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Background and Purpose:  We aimed to examine the histological characteristics of vastus lateralis muscles in patients undergoing total hip arthroplasty (THA) following femoral neck fractures and to explore the correlation between muscle fiber types and postoperative functional recovery., Methods:  34 patients undergoing THA for femoral neck fractures were included. A biopsy of the vastus lateralis muscle was performed during surgery, followed by immunohistochemical staining. Subsequently, image analysis was conducted to measure the average area of muscle fiber types and the number of type I and II muscle fibers, and the ratio of the area and the number of type II muscle fibers. Functional recovery was assessed 2 weeks post-surgery using the Short Physical Performance Battery (SPPB)., Results: A significant positive correlation was observed between type II muscle fibers and SPPB scores. The ratio of type II muscle fiber area and number strongly correlated with the SPPB scores, indicating a robust static association. The average area of type II fibers showed a strong correlation (r = 0.63, P < 0.001), as did the number of type II fibers (r = 0.53, P = 0.001). Moreover, the ratio of type II muscle fiber area and number significantly correlated with SPPB scores (area: r = 0.77, P < 0.001; number: r = 0.51, P = 0.002), indicating that larger and more numerous type II fibers are associated with better physical performance., Conclusion: The reduction of type II muscle fibers was strongly correlated with a low SPPB postoperative functional recovery in patients who underwent THA following femoral neck fractures.

Background: Treatment of femoral neck fractures in patients who are nongeriatric (≤ 60 years) is challenging because of high failure rates. Anatomic parameters influence the biomechanical environment for fracture healing, but their associations with clinical prognosis remains unclear., Questions/purposes: (1) Which anatomic parameter that is identifiable on pelvic radiographs shows a statistical correlation with a higher risk of clinical failure defined as nonunion, avascular necrosis (AVN), reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference) in the screw fixation of femoral neck fractures among nongeriatric patients? (2) How does the influence of anatomic parameters on clinical prognosis manifest: directly or mediated by additional mechanisms?, Methods: This retrospective, multicenter study used a nationwide database in China. Between January 2014 and December 2020, we evaluated 1066 patients with femoral neck fractures with a median age of 53 years (interquartile range 46 to 56) and median follow-up period of 62 months. Anatomic parameters including femoral neck-shaft angle (NSA), femoral head radius, femoral neck width, femoral offset, acetabular center-edge angle, and acetabular sharp angle were variables of interest. The primary outcome was clinical failure including nonunion, AVN, reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference). Risk factors for failure were first filtered using the Bayesian information criterion and then assessed with multiple regression adjusting for confounders. The mediation effect was further explored using model-based causal mediation analysis with a quasi-Bayesian Monte Carlo method., Results: Of all anatomic parameters we assessed, the contralateral NSA was associated with clinical failure, after adjusting for all potential covariates and confounding variables (adjusted odds ratio 0.92 [95% confidence interval 0.89 to 0.95]; p < 0.001). The optimal threshold for the NSA was 130°, with the highest Youden index of 0.27. Patients with an NSA < 130° (41% [441 of 1066]) demonstrated an increased occurrence of nonunion (15% [68 of 441] versus 5% [33 of 625]; p < 0.001), AVN (32% [141 of 441] versus 22% [136 of 625]; p < 0.001), functional failure (25% [110 of 441] versus 15% [93 of 625]), and reoperations (28% [122 of 441] versus 13% [79 of 625]). The impact of an NSA less than 130° on clinical failure was direct and substantially mediated by the type of displaced fracture (mediation proportion: 18.7%)., Conclusion: In our study of screw fixations for femoral neck fractures among nongeriatric patients, we identified that a contralateral NSA < 130° correlates with an increased risk of clinical failure including nonunion, AVN, functional failure, and reoperation. The effect is either direct or mediated through displaced fracture types. This is important for surgeons in order to recognize the elevated rate of clinical failure and nature of the challenging biomechanical environment, which should guide them in refining surgical details and selecting appropriate fixation and rehabilitation plans. Approaches to managing these fractures require further validation with large-scale clinical trials., Level of Evidence: Level III, prognostic study., Competing Interests: All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the Association of Bone and Joint Surgeons.)

To analyze the fixation strength of cannulated screws fixation in the treatment of femoral neck fracture with posterior tilt due to insufficient reduction. Two sets of digital models of anatomical reduction and 15° tilting reduction were established by CT data. Each group of models was modeled with two different fixation methods. One fixation method was fixed according to the standard cannulated screws recommended by AO. Another fixation method is to tilt the screw posterior tilt 15°. The final four groups of models were obtained: AO principle nailing posterior tilt model (Group A), posterior direction nailing posterior tilt model (Group B), AO principle nailing anatomic reduction model (Group C) and posterior direction nailing anatomic reduction model (Group D). The maximum displacement of the fracture end, the maximum Von-Mises stress and the stress distribution of the internal fixation were compared among the four groups. Four groups of models were established on artificial bone by 3D printing guide plate technology. The 600 N pressure test and yield test were performed on a biomechanical machine. The finite element and biomechanical models showed that groups B and C were more stable than groups A and D. The stability of group B was not worse than that of group C. When the femoral neck fracture produces a posterior tilt, a posterior reduction is allowed. The change of AO screw to posterior tilting screw fixation has more powerful advantages. No posterior tilt or posterior reduction, AO screw placement is still required.

Introduction: Several internal fixation devices are available for treating Pauwels type I, II and III femoral neck fractures. The present study compared various fixation implants for all Pauwels fracture types using a CT-based subject-specific finite element model of the femur and determined the most effective implant for each fracture type., Materials and Methods: The analysis included four different configurations of cannulated screw models, Femoral Neck System, Dynamic Hip Screw and Dynamic Condylar Screw (with and without anti-rotational screw). Ti-alloy was considered as the implant material. Heterogeneous bone material property was assigned based on CT grey value. Frictional contact was assumed in the contact interfaces. Peak loading corresponding to normal walking and stair-climbing were considered. Equivalent strain in bone, equivalent stress in the implants, femoral head deformation and rotation, micromotion in the contact interfaces, and strain-shielding in bone were evaluated for each implanted model., Results: Stresses generated in the implants were within the yield limit of the implant material. In Pauwels I and II, the micromotion predicted at the contact regions in all the implanted models was within 100 µm, which is suitable for bone integration. However, in Pauwels III fracture, most of the implanted models other than DHS with AR-screw model exhibited micromotion of more than 150 µm in the contact regions, which is expected to inhibit bone growth., Conclusions: The DHS with AR-screw implanted model was identified as the most effective in treating Pauwels I and III fractures. However, for Pauwels type II, DCS with an AR-screw implant was deemed superior to the other configurations., Competing Interests: Declaration of competing interest We hereby state that there are no financial and personal relationships with other people and organizations with regard to the submission of this manuscript., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: This study aimed to compare the clinical outcomes and differences in biomechanical characteristics between the femoral neck system (FNS) and cannulated cancellous screws (CCSs) in the treatment of femoral neck fractures., Methods: This study retrospectively analysed a cohort of 38 registered cases of femoral neck fractures treated surgically with either the FNS (n = 17) or CCSs (n = 21) between January 2020 and December 2023. Indicators such as fluoroscopy frequency, length of hospital stay, and fracture healing time were compared between the two groups. Functional status was evaluated via the Harris hip score (HHS) and visual analogue scale (VAS), whereas prognosis was assessed based on changes in the neck shaft angle and femoral neck shortening. Additionally, six sets of femoral neck fracture models were developed based on Pauwels angles of 30°, 40°, 50°, 60°, 70°, and 80°. Two experimental groups, FNS and CCS, were established, and a joint reaction force of 1800 N was applied to the proximal femur. The displacement, stress, and stiffness of the components of interest in the different models were tested and compared., Results: The distributions of all the baseline characteristics were similar between the two groups (p > 0.05). The FNS group presented significantly shorter fluoroscopy frequency, length of hospital stay, and fracture healing time (p < 0.05). Harris and VAS scores were higher in the FNS group than in the CCS group (p < 0.05). Postoperative changes in the neck shaft angle and femoral neck shortening were significantly lower in the FNS group than in the CCS group (p < 0.05). The results of the finite element analysis indicated that the maximum stress on the femoral head and varus angle were generally lower in the FNS group than in the CCS group and that the maximum displacement of the femoral head and FNS was generally lower in the FNS group than in the CCS group. However, the superiority of FNS over CCS decreased with increasing Pauwels angle. Additionally, the effectiveness of FNS in limiting displacement of the femoral neck upper wall was not as favourable as that of CCS., Conclusions: The treatment of femoral neck fractures with FNS is superior and contributes to improved hip joint function. Biomechanical research has confirmed its structural stability and advantages in resisting femoral head varus. However, challenges to its fixation efficacy persist, particularly at higher Pauwels angles., (© 2024. The Author(s).)

Objective: There is currently a lack of in-depth comparative evaluation regarding the biomechanical properties of novel intramedullary nail devices in the treatment of basal femoral neck fractures (BFNF). This study aims to utilize finite element analysis to compare the performance differences of two novel devices with traditional PFNA and InterTan nails in the fixation of BFNF., Methods: Based on a validated finite element model, this study constructed an accurate BFNF model and implanted four different intramedullary nail devices: PFNA, InterTan nail, PFBN (proximal femoral biomimetic nail), and NIS (novel intramedullary system). Under a vertical load of 2100N, the displacement and Von Mises stress (VMS) distribution of each group of models were evaluated through simulation testing., Results: Under a load of 2100N, the PFBN device exhibited the best performance in terms of displacement and peak stress, while PFNA performed poorly. The peak displacement of the NIS device was lower than that of PFNA and InterTan nails, while the peak stress of the InterTan nail was lower than that of PFNA and NIS., Conclusion: The PFBN device demonstrates stronger load-bearing and shear-resistant properties in the treatment of BFNF, and the NIS device also shows significant improvement in stability. Therefore, both the PFBN and NIS devices are reliable internal fixation techniques for the treatment of CFIFs, with potential clinical application prospects., (© 2024. The Author(s).)

This study aims to evaluate the biomechanical performance of the Gamma 3 nail with an anti-rotation screw (GNS) and compare it to two established gold-standard methods for treating unstable femoral neck fractures (UFNFs). Synthetic bone models were prepared with Pauwels' type III osteotomy and an additional posterior wedge. Three different implant configurations were tested: three cannulated crews (3CS) in an inverted triangle configuration, a dynamic hip screw with an anti-rotation screw (DHSS), and GNS. Non-destructive cyclic axial loading was applied at 7° adduction, with 1000 cycles ranging from 100 to 1000 N. Subsequently, a construct failure test was conducted using progressive axial compression, and fracture reduction loss was recorded. The average axial stiffness was 321 ± 52 N/mm for 3CS, 430 ± 71 N/mm for DHSS, and 519 ± 104 N/mm for GNS. The average ultimate failure loads were 2699.3 N for 3CS, 3427.1 N for DHSS, and 3758.9 N for GNS. GNS demonstrated significantly greater axial stiffness compared to the other two groups (P < 0.05). Both DHSS and GNS exhibited similar failure loading, which were greater than those of 3CS (P < 0.05). GNS offers the advantages of a minimally invasive and intramedullary implant with comparable stability to the DHSS system. Moreover, GNS demonstrated superior biomechanical performance compared to 3 CS configuration., (© 2024. The Author(s).)

Introduction: Reconstruction nails are commonly used to treat proximal femur fractures, with cephalic screw placement for femoral neck "prophylaxis" becoming standard practice. These implants are traditionally introduced through piriformis fossa (PF) or greater trochanter (GT) entry portals. A third "central collinear" (CC) portal has been proposed that allows entry along the femoral anatomic axis and central placement of cephalic screws. The present study aimed to quantify and compare the CC portal femoral neck strength with the two traditional (PF and GT) entry portals., Materials and Methods: Eighteen cadaveric femur specimens (nine matched pairs) were divided into three groups using a balanced incomplete block design to control for variations in age and sex: (1) GT, (2) CC, and (3) PF entry points. Specimens and implants were cut to a standard length and instrumented with straight or valgus bend nails of appropriate laterality and two cephalic screws. Specimens were mounted on a custom jig replicating load distribution along the mechanical axis. A 100 N compressive preload was applied to the femoral head, followed by loading to failure at a rate of 10 mm/s until fracture, indicated by 30 % drop in axial force., Results: THE THREE ENTRY POINTS DID NOT DIFFER IN LOAD-TO-FAILURE: GT (6378.7 ± 1494.9 N), P (6912.4 ± 4924.1 N) and CC (7044.2 ± 2911.4 N) (P = 0.948) or maximum displacement, stiffness, and toughness. Most PF specimens failed at the basicervical neck, whereas most GT specimens failed at the subcapital neck; these differences were not significant. CC specimens failed evenly split between subcapital and basicervical., Conclusion: There were no significant difference in femoral neck load-to-failure after placement of a reconstruction nail through a CC entry portal when compared to both GT and PF entry. Clinically, this suggests the CC entry portal is a viable option when clinical considerations warrant its use., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sapan Shah reports financial support and equipment, drugs, or supplies were provided by AOTNA. Melodie Metzger reports a relationship with Arthrex Inc that includes: funding grants. Geoffrey Marecek reports a relationship with Bone Support AB that includes: consulting or advisory. Geoffrey Marecek reports a relationship with DePuy Orthopaedics Inc that includes: consulting or advisory. Geoffrey Marecek reports a relationship with Globus Medical Inc that includes: consulting or advisory, equity or stocks, and funding grants. Geoffrey Marecek reports a relationship with NuVasive Inc that includes: consulting or advisory. Geoffrey Marecek reports a relationship with Orthofix Medical Inc that includes: consulting or advisory. Geoffrey Marecek reports a relationship with restore 3D that includes: consulting or advisory and equity or stocks. Geoffrey Marecek reports a relationship with Siemens Medical Solutions USA Inc that includes: consulting or advisory. Geoffrey Marecek reports a relationship with Zimmer Inc that includes: consulting or advisory. Melodie Metzger reports a relationship with Robson Forensic Inc that includes: paid expert testimony. Geoffrey Marecek - AAOS Comprehensive Review editorial board, AOTNA committee member If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The selection of implants for fixing unstable femoral neck fractures (FNF) remains contentious. This study employs finite element analysis to examine the biomechanics of treating Pauwels type III femoral neck fractures using cannulated compression screws (3CS), biplane double-supported screw fixation (BDSF), and the femoral neck system (FNS). A three-dimensional model of the proximal femur was developed using computed tomography scans. Fracture models of the femoral neck were created with 3CS, BDSF, and FNS fixations. Von Mises stress on the proximal femur, fracture ends, internal fixators, and model displacements were assessed and compared across the three fixation methods (3CS, BDSF, and FNS) during the heel strike of normal walking. The maximum Von Mises stress in the proximal fragment was significantly higher with 3CS fixation compared to BDSF and FNS fixations (120.45 MPa vs. 82.44 MPa and 84.54 MPa, respectively). Regarding Von Mises stress distribution at the fracture ends, the highest stress in the 3CS group was 57.32 MPa, while BDSF and FNS groups showed 51.39 MPa and 49.23 MPa, respectively. Concerning implant stress, the FNS model exhibited greater Von Mises stress compared to the 3CS and BDSF models (236.67 MPa vs. 134.86 MPa and 140.69 MPa, respectively). Moreover, BDSF displayed slightly lower total displacement than 3CS fixation (7.19 mm vs. 7.66 mm), but slightly higher displacement than FNS (7.19 mm vs. 7.03 mm). This study concludes that BDSF outperforms 3CS fixation in terms of biomechanical efficacy and demonstrates similar performance to the FNS approach. As a result, BDSF stands as a dependable alternative for treating Pauwels type III femoral neck fractures., (© 2024. The Author(s).)

Background: Basicervical femoral neck fracture is a rare proximal femur fracture with a high implant failure rate. Biomechanical comparisons between cephalomedullary nails (CMNs) and dynamic hip screws (DHSs) under torsion loading are lacking. This study compared the biomechanical performance of three fixations for basicervical femoral neck fractures under torsion load during early ambulation., Methods: The biomechanical study models used three fixations: a DHS, a DHS with an anti-rotation screw, and a short CMN. Finite element analysis was used to simulate hip rotation with muscle forces related to leg swing applied to the femur. The equivalent von Mises stress (EQV) on fixation, fragment displacement, and strain energy density at the proximal cancellous bone were monitored for fixation stability., Results: The EQV of the short CMN construct (304.63 MPa) was comparable to that of the titanium DHS construct (293.39 MPa) and greater than that of the titanium DHS with an anti-rotation screw construct (200.94 MPa). The proximal fragment displacement in the short CMN construct was approximately 0.13 mm, the greatest among the constructs. The risk of screw cutout for the lag screw in short CMNs was 3.1-5.8 times greater than that for DHSs and DHSs with anti-rotation screw constructs., Conclusions: Titanium DHS combined with an anti-rotation screw provided lower fragment displacement, stress, and strain energy density in the femoral head than the other fixations under torsion load. Basicervical femoral neck fracture treated with CMNs may increase the risk of lag screw cutout., (© 2024. The Author(s).)

Background: The purpose of this study was to compare the outcomes of femoral neck shortening between the femoral neck system (FNS) and the cannulated cancellous screws (CCS) for displaced femoral neck fractures in young adults PATIENTS AND METHODS: In this retrospective analysis, 225 patients aged 18-65 years with displaced femoral neck fracture were divided into two groups according to internal fixation: 135 patients in the FNS group and 90 patients in the CCS group. The length of hospital stay, duration of surgery, intraoperative blood loss, quality of reduction, extent of femoral neck shortening, incidence of femoral neck shortening, femoral neck shortening at each follow-up visit, Harris hip score (HHS), reoperation, and complications were compared between the two groups., Results: The median follow-up time was 28.2 (26.0, 31.2) months in the FNS group and 30.2 (26.3, 34.7) months in the CCS group. The follow-up time, age, sex distribution, body mass index (BMI), mechanism of injury, injured side, length of hospital stay, time from injury to surgery, and fracture classification were similar between the groups. Duration of surgery was longer in the FNS group (65.0 (55.0, 87.0) min versus 55.0 (50.0, 65.0) min, P<0.001); intraoperative blood loss was greater in the FNS group (50.0 (20.0, 60.0) ml versus 20.0 (10.0, 35.0) ml, P<0.001). Femoral neck shortening was 2.4 (1.0, 4.5) mm in the FNS group versus 0.6 (0.0, 2.6) mm in the CCS group at 1 month postoperatively (P<0.001); 3.7 (1.8, 6.4) mm in the FNS group versus 1.2 (0.6, 3.8) mm in the CCS group at 3 months (P<0.001); 4.1(2.4, 7.7) mm in the FNS group versus 2.3 (1.1, 4.4) mm in the CCS group at 6 months (P<0.001); 4.2 (2.6, 7.7) mm in the FNS group versus 2.6 (1.3, 4.6) mm in the CCS group at 12 months (P<0.001); and 4.5 (2.8, 8.0) mm in the FNS group versus 2.8 (1.5, 4.8) mm in the CCS group at 18 months (P<0.001). The two groups showed no significant differences in HHS, reoperation, and reduction quality., Conclusion: Compared to CCS, FNS is deficient in preventing femoral neck shortening. Future research should focus on improving FNS in terms of preventing femoral neck shortening., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The choice between cemented or uncemented stem fixation in the treatment of a femoral neck fracture may influence patient rehabilitation and the resulting gait pattern, due to potential differences in implant positioning and fixation. We used gait analysis to study temporal gait parameters, hip kinematics and kinetics in patients who, 2 years previously, had been randomised to treatment with a cemented or uncemented stem and due to an acute femoral neck fracture., Methods: 45 Patients implanted with a cemented Lubinus SP II ( n  = 29) and an uncemented ( n  = 16) Corail stem were studied. Gait analysis was performed using a 16-camera motion capture system and force plates. 28 subjects served as controls. Temporal gait parameters, hip kinematics and kinetics were analysed. The patients had no or minimum pain (median Harris pain score 44, range 40-44) and the majority had no limp (median Harris limp score 11, range 5-11)., Results: Temporospatial gait parameters and abduction-adduction motions and moments did not differ between patients with cemented or uncemented stems ( p   >  0.05). Patients with cemented stems did, however, show more hip flexion and less extension during walking than those with an uncemented stem ( p  < 0.05). Moreover, the flexion-extension range was less in the cemented group ( p  < 0.04). Compared with controls, the hip fracture patients walked more slowly, with a shorter stride length and a longer stance phase., Conclusions: Increased hip flexion and reduced extension in patients using the Lubinus SP II cemented stem could be an effect of its anteverted neck, but this question requires further study. Despite acute treatment with THA, hip fracture patients demonstrated a change in gait pattern compared with controls 2 years after the operation. This suggests that these changes are caused by the presence of an implant, or the soft-tissue trauma partly caused by the surgery than by any degenerative disease present in patients undergoing elective surgery.ClinicalTrials.gov Identifier: NCT04791605., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Introduction: American orthopaedists are increasingly seeking fellowship sub-specialization. One proposed benefit of fellowship training is decrease in complications, however, few studies have investigated the rates of medical and surgical complications for hip fracture patients between orthopedists from different fellowship backgrounds. This study aims to investigate the effect of fellowship training and case volume on medical and surgical outcomes of patient following hip fracture surgical intervention., Methods: 1999-2016 American Board of Orthopedic Surgery (ABOS) Part II Examination Case List data were used to assess patients treated by trauma or adult reconstruction fellowship-trained orthopedists versus all-other orthopaedists. Rates of surgeon-reported medical and surgical adverse events were compared between the three surgeon cohorts. Using binary multivariate logistic regression to control of demographic factors, independent factors were evaluated for their effect on surgical complications., Results: Data from 73,427 patients were assessed. An increasing number of hip fractures are being treated by trauma fellowship trained surgeons (9.43% in 1999-2004 to 60.92% in 2011-2016). In multivariate analysis, there was no significant difference in type of fellowship, however, surgeons with increased case volume saw significantly decreased odds of complications (16-30 cases: OR = 0.91; 95% CI: 0.85-0.97; p = 0.003; 31+ cases: OR = 0.68; 95% CI: 0.61-0.76; p<0.001). Femoral neck hip fractures were associated with increased odds of surgical complications., Discussion: Despite minor differences in incidence of surgical complications between different fellowship trained orthopaedists, there is no major difference in overall risk of surgical complications for hip fracture patients based on fellowship status of early orthopaedic surgeons. However, case volume does significantly decrease the risk of surgical complications among these patients and may stand as a proxy for fellowship training. Fellows required to take hip fracture call as part of their training regardless of fellowship status exhibited decreased complication risk for hip fracture patients, thus highlighting the importance of additional training., Competing Interests: The authors have declared that no competing interests exist.

Closed reduction and internal fixation with three cannulated compression screws is a common method for treating femoral neck fractures in young and middle-aged patients. Protocols including the inverted triangle configuration and dispersion of the screws still needed further supports. The purpose of this study was to explore a novel oblique triangle configuration (OTC) of three screws in fixing femoral neck fractures based on the morphology of the femoral neck isthmus (FNI). The computer-aided design modules were used to explore the ideal spatial configuration with largest triangle by three parallel screws. A univariate evaluation model was established based on the oval-like cross-section of the FNI. When the three screws were positioned by the OTC, Inverted Equilateral Triangle Configuration (IETC), and the Maximum Area Inverted Isosceles Triangle Configuration (MA-IITC) respectively, the proportion of area and circumference in the cross-section of FNI and the changing trend of proportion were compared under various torsion angles, eccentricity, and cross-sectional area of FNI. The area and circumference ratios of the parallel screws using the OTC method were significantly higher than in the IETC and MA-IITC groups. In the univariate evaluation model, the OTC area ratio and circumference ratio remained stable under the different femoral neck torsion angles, FNI cross-sectional area, and eccentricity. The OTC method provided an ideal spatial configuration for the FNA fixation with the largest area using three parallel screws. The position of the posterior screw was also away from the metaphyseal artery, potentially reducing the possibility of vascular injury and screw penetrating., (© 2022. The Author(s).)

Decline of bone mineral density (BMD) during menopause is related to increased risk of fractures in postmenopausal women, however, this relationship in premenopausal women has not been established. To quantify this relationship, real-world data (RWD) from the National Health and Nutrition Examination Survey (NHANES), and longitudinal data from the elagolix phase III clinical trials were modeled across a wide age range, and covariates were evaluated. The natural changes in femoral neck BMD (FN-BMD) were well-described by a bi-exponential relationship with first-order BMD formation (k 1 ) and resorption (k 2 ) rate constants. Body mass index (BMI) and race (i.e., Black) were significant predictors indicating that patients with high BMI or Black race experience a relatively lower BMD loss. Simulations suggest that untreated premenopausal women with uterine fibroids (UFs) from elagolix phase III clinical trials (median age 43 years [minimum 25-maximum 53]) lose 0.6% FN-BMD each year up to menopausal age. For clinical relevance, the epidemiological FRAX model was informed by the simulation results to predict the 10-year risk of major osteoporotic fracture (MOF). Premenopausal women with UFs, who received placebo only in the elagolix phase III trials, have a projected FN-BMD of 0.975 g/cm 2 at menopause, associated with a 10-year risk of MOF of 2.3%. Integration of modeling, RWD, and clinical trials data provides a quantitative framework for projecting long-term postmenopausal risk of fractures, based on natural history of BMD changes in premenopausal women. This framework enables quantitative evaluation of the future risk of MOF for women receiving medical therapies (i.e., GnRH modulators) that adversely affect BMD., (© 2021 AbbVie Inc. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Background: Femoral neck shortening can occur in young patients receiving internal fixation for Pauwels type II femoral neck fracture. The risk factors for neck shortening, which can affect hip function, are not clear. This study aimed to retrospectively identify risk factors for neck shortening after internal fixation with parallel partially threaded cannulated cancellous screws (FPTCS) for Pauwels type II femoral neck fracture in relatively young patients., Methods: Clinical data from 122 cases with Pauwels type II femoral neck fracture from February 2014 to February 2019 were reviewed and analyzed, and causes of neck shortening were statistically analyzed. And the Chi-squared test or Fisher's exact test was used to compare indicators. Multivariate analysis was conducted with non-conditional logistic regression analysis., Results: Statistically significant differences were found in age, sex, BMD, BMI, fracture type, posterior medial cortex comminution, and reduction quality between patients with femoral neck shortening and those without femoral neck shortening. Logistic regression analysis showed that fracture type, posterior medial cortex comminution, and reduction quality were the main risk factors for neck shortening., Conclusion: Fracture type, posterior medial cortex comminution, and reduction quality can be used as important reference indexes to predict the possibility of neck shortening after internal fixation with FPTCS for Pauwels type II femoral neck fracture in young patients. BMD and BMI may be also risk factors.

Background: THA is a reasonable surgical option for some patients with fragility fractures of the femoral neck, but it has the risk of prosthesis dislocation. The prosthesis combination that reduces the risk of dislocation and the rate of revision surgery is not known., Questions/purposes: In patients receiving primary THA for a femoral neck fracture, does (1) the rate of all-cause revision or (2) the reason for revision and rate of revision for dislocation differ among THA with a standard head size, large head size, dual mobility (DM), or constrained liner? (3) Is there a difference in the revision risk when patients are stratified by age at the time of surgery?, Methods: Data were analyzed for 16,692 THAs performed to treat fractures of the femoral neck reported in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from January 2008 to December 2018, as this included the first use of DM prostheses. The AOANJRR includes information on more than 98% of arthroplasty procedures performed in Australia. Most patients were female (72%) and the mean age was 74 years ± 11. There were 8582 standard-head prostheses, 5820 large-head prostheses, 1778 DM prostheses, and 512 constrained prostheses identified. The cumulative percent revision (CPR) was determined for all causes as well as CPR for dislocation. The time to the first revision was described using Kaplan-Meier estimates of survivorship, with right censoring for death or closure of the database at the time of analysis. The unadjusted CPR was estimated each year of the first 10 years for standard heads, 10 years for large heads, 8 years for constrained liners, and 7 years for DM prostheses, with 95% confidence intervals using unadjusted pointwise Greenwood estimates. The results were adjusted for age, sex, femoral fixation, and head size where appropriate and were considered by age groups < 70 and ≥ 70 years., Results: When adjusted for age, sex, femoral fixation and head size, there was no difference in the rate of all-cause revision at 7 years for any of the four groups. There was no difference in the rate of all-cause revision when patients were stratified by < 70 or ≥ 70 years of age. Dislocation was the most common reason for revision (32%). When analyzing revision for dislocation alone, large-head THA had a lower rate of revision for dislocation compared with standard head (HR 0.6 [95% CI 0.4 to 0.8]; p < 0.001) and DM prostheses had a lower rate of revision for dislocation than standard head for the first 3 months (HR 0.3 [95% CI 0.1 to 0.7]; p < 0.004) but not after this time point., Conclusion: The Australian registry shows that there is no difference in the rate of all-cause revision for standard-head, large-head, DM prostheses or constrained liner THA after femoral neck fractures for all patients or for patients stratified into younger than 70 years and at least 70 years of age groups. Dislocation is the most common cause of revision. Large-head prostheses are associated with a lower revision risk for dislocation and DM prostheses have a lower rate of revision for dislocation than standard heads for the first 3 months only. Surgeons treating a femoral neck fracture with THA might consider a large head size if the diameter of the acetabulum will allow it and a DM prosthesis if a large head size is not possible. The age, life expectancy and level of function of patients with femoral neck fractures minimizes the potential long-term consequences of these prostheses. The lack of significant differences in survival between most prosthesis combinations means surgeons should continue to look for factors beyond head size and prosthesis to minimize dislocation and revision surgery., Level of Evidence: Level III, therapeutic study., Competing Interests: Each author certifies that neither he or she, nor any member of his or her immediate family, has funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2020 by the Association of Bone and Joint Surgeons.)

Background: A successful osseointegration of total hip arthroplasty (THA) relies on the interplay of implant surface and bone marrow microenvironment. This study was undertaken to investigate the impact of perioperative biochemical molecules (Ca 2+ , Mg 2+ , Zn 2+ , VD, PTH) on the bone marrow osteogenetic factors (BMP2, BMP7, Stro-1 + cells) in the metaphyseal region of the femoral head, and further on the bone mineral density (BMD) of Gruen R3., Methods: Bone marrow aspirates were obtained from the discarded metaphysis region of the femoral head in 51 patients with THA. Flow cytometry was used to measure the Stro-1 + expressing cells. ELISA was used to measure the concentrations of bone morphologic proteins (BMP2 and BMP7) and the content of TRACP5b in serum. TRAP staining was used to detect the osteoclast activity in the hip joint. The perioperative concentrations of the biochemical molecules above were measured by radioimmunoassay. The BMD of Gruen zone R3 was examined at 6 months after THA, using dual-energy X-ray absorptiometry (DEXA)., Results: Our data demonstrated that the concentration of Ca 2+ was positively correlated with BMP7 expression, and with the postoperative BMD of Gruen zone R3. However, the concentration of Mg 2+ had little impact on the R3 BMD, although it was negatively correlated with the expression of BMP7. Osteoclast activity in hip joint tissue of patients with femoral neck fractures was increased. Compared with the patients before THA, the levels of TRACP5b in serum of patients after THA were decreased. The data also suggested that the other biochemical molecules, such as Zn 2+ , VD, and PTH, were not significantly correlated with any bone marrow osteogenetic factors (BMP2, BMP7, Stro-1 + cells). The postoperative R3 BMD of patients of different gender and age had no significant difference., Conclusions: These results indicate the local concentration of Ca 2+ may be an indicator for the prognosis of THA patients.

Introduction: Femoral neck fractures are a major problem in orthopaedic practice, having a huge impact on society, and involving a large number of elderly patients for whom early recovery is paramount. Thus, the aim of this study was to compare 2 surgical approaches, direct anterior (DA group) versus posterolateral (PL group), used for bipolar hip hemiarthroplasty (BHA) with femoral neck fractures in order to assess pain recovery after surgery. Our hypothesis was that early pain recovery would be faster in the DA group., Methods: 100 patients were randomised to surgery using either a DA group or PL group approach, and were then followed up for 6 months. Surgical time, intra- and postoperative complications were recorded for each patient. The main outcome, pain, was recorded using an NRS scale at 3 days, 1, 3 and 6 months after surgery. At the same time, patient status was evaluated using Activities of Daily Living and Cumulated Ambulation Score scales., Results: Surgical time was longer in the DA group ( p   <  0.0001). Pain perception at 3 days and at 1 month after surgery was significantly lower in DA group patients ( p   <  0.0001). The results of the other scales were comparable in the 2 groups (at 3 days, 1 and 3 months after surgery)., Discussion: The DA approach offers a significant advantage in terms of pain perception up to 1 month after the operation. Early recovery in terms of pain perception is an important finding. Future studies should explore whether this early pain reduction could translate into a faster rehabilitation programme for an earlier recovery of full function.Clinical trial registration: Protocol 423/CE; Study n. CE 41/15.

Background: The risk of femoral neck fracture progressively increases with age. However, the reasons behind this consistent increase in the fracture risk can't be completely justified by the decrease in the bone mineral density. The objective of this study was to analyze the correlation between various bone structural features and age., Study Design & Methods: A total of 29 consecutive patients who suffered an intracapsular hip fracture and underwent joint replacement surgery between May 2012 and March 2013 were included in this study. A 2 cm × 1 cm Ø cylindrical trabecular bone sample was collected from the femoral heads and preserved in formaldehyde. Bone mineral density (BMD), microarchitecture, organic content and crystallography were analyzed using a Dual-energy X-ray absorptiometry scan, micro-CT scan, and high resolution magic-angle-spinning-nuclear magnetic resonance (MAS-NMR), respectively. Statistical correlations were made using Spearman´s or Pearson´s correlation tests depending on the distribution of the continuous variables., Results: The mean patient age was 79.83 ± 9.31 years. A moderate negative correlation was observed between age and the hydrogen content in bone ( 1 H), which is an indirect estimate to quantify the organic matrix (r = -0.512, p = 0.005). No correlations were observed between BMD, trabecular number, trabecular thickness, phosphorous content, apatite crystal size, and age (r = 0.06, p = 0.755; r = -0.008, p = 0.967; r = -0.046, p = 0.812; r = -0.152, p = 0.430, respectively). A weak positive correlation was observed between Charlson´s comorbidity index (CCI) and c-axis of the hydroxiapatite (HA) crystals (r = -0.400, p = 0.035)., Conclusion: The femoral head relative protein content progressively decreases with age. BMD was not correlated with other structural bone parameters and age. Patients with higher comorbidity scores had larger HA crystals. The present results suggest that the progressive increase in the hip fracture risk in elderly patients could be partially explained by the lower bone protein content in this age group., Competing Interests: Declaration of Competing Interest All authors declare no conflict of interest in relation to the content of this study., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The aim of this study was to investigate the effect of Gotfried positive reduction (GPR) on repair of femoral neck fracture in rabbits and its underlying mechanisms. Male New Zealand white rabbits were employed to establish the model of femoral neck fracture. All the rabbits were randomly divided into four groups: control, open accurate reduction (OR), closed Gotfried negative support reduction (CR-N) and closed Gotfried positive support reduction (CR-P). At the 8th and 12th week after surgery, the anteroposterior and lateral radiographs of their hip joints were taken by X-ray, and local hemodynamics of their hip joints was detected by ultrasound. Histological examination was evaluated by HE staining and bone biological strength test was measured by testing machine, which was performed to study the repair of femoral neck fracture. Osteogenesis and angiogenesis-related proteins were measured by western blot in bone tissues and synovial tissues. The results revealed that the fracture healing intensity and blood supply in CR-P were better than those in CR-N and much more excellent than those in OR. In addition, the content of bone morphogenetic protein2 (BMP2), platelet derived growth factor (PDGF) and ocsteocalcin was higher in CR-P group than in CR-N, while lower in CR-P than OR. Furthermore, the expression of BMP2, COL-2 and angiopoietin (ANGPT) was upregulated in CR-P compared to CR-N and OR. Taken together, our results indicated that GPR was able to promote the repair of femoral neck fracture via enhancing osteogenesis and angiogenesis, which is valuable to us and shows good application prospect in bone tissue repair., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2019 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Our study aimed to examine the status of plasma fatty acids (FAs), inflammatory markers, and lipid peroxidation in patients with femoral neck fractures. The study included 20 patients (64-86 years) with femoral neck fractures indicated for surgery and a control group of 17 elderly subjects without fractures or serious chronic diseases. Plasma was obtained during the first 12 h postfracture and presurgery and 7 days postop. Compared to the control, patients had significantly higher saturated FA (SFA) and monounsaturated FA as well as increased TNF-α and IL-6. Opposite to that, levels of individual and total n -6 polyunsaturated FA (PUFA), individual and total n -3 PUFA, n -6/ n -3 ratio, and levels of thiobarbituric acid reactive substances (TBARS) were markedly lower in the patient than in the controls. On the seventh day after the surgery, we showed a further rise in the SFA, oleic acid, and TNF-α and reductions of n -6 PUFA and IL-6. Taken together, our results suggest that altered FA status, especially reduced PUFA, may influence hip fracture repair and even contribute to femoral fracture susceptibility in the elderly. A potential benefit from nutritional intervention with PUFA in prevention and (or) fracture healing should be considered.

A case-control study assessing the association of DXA-derived 3D measurements at lumbar spine with osteoporotic hip fractures was performed. Stronger association was found between transcervical hip fractures and integral (AUC = 0.726), and cortical (AUC = 0.696) measurements at the lumbar spine compared with measurements at the trabecular bone (AUC = 0.617); although femur areal bone mineral density (aBMD) remains the referent measurement for hip fracture risk evaluation (AUC = 0.838)., Purpose: The aim of the present study was to evaluate the association between DXA-derived 3D measurements at lumbar spine and osteoporotic hip fractures., Methods: We analyzed a case-control database composed by 61 women with transcervical hip fractures and 61 age-matched women without any type of fracture. DXA scans at lumbar spine were acquired, and areal bone mineral density (aBMD) was measured. Integral, trabecular and cortical volumetric BMD (vBMD), cortical thickness, and cortical surface BMD (sBMD) at different regions of interest were assessed using a DXA-based 3D modeling software. Descriptive statistics, tests of difference, odds ratio (OR), and area under the receiver operating curve (AUC) were used to compare hip fracture and control groups., Results: Integral vBMD, cortical vBMD, cortical sBMD, and cortical thickness were the DXA-derived 3D measurements at lumbar spine that showed the stronger association with transcervical hip fractures, with AUCs in the range of 0.685-0.726, against 0.670 for aBMD. The highest AUC (0.726) and OR (2.610) at the lumbar spine were found for integral vBMD at the posterior vertebral elements. Significantly, lower AUC (0.617) and OR (1.607) were found for trabecular vBMD at the vertebral body. Overall, total femur aBMD remains the DXA-derived measurement showing the highest AUC (0.838) and OR (6.240)., Conclusion: This study showed the association of DXA-derived measurements at lumbar spine with transcervical hip fractures. A strong association between vBMD at the posterior vertebral elements and transcervical hip fractures was observed, probably because of global deterioration of the cortical bone. Further studies should be carried out to investigate on the relative risk of transcervical fracture in patients with long-term cortical structural deterioration.

Background: Globally, hip fractures are among the top 10 causes of disability in adults. For displaced femoral neck fractures, there remains uncertainty regarding the effect of a total hip arthroplasty as compared with hemiarthroplasty., Methods: We randomly assigned 1495 patients who were 50 years of age or older and had a displaced femoral neck fracture to undergo either total hip arthroplasty or hemiarthroplasty. All enrolled patients had been able to ambulate without the assistance of another person before the fracture occurred. The trial was conducted in 80 centers in 10 countries. The primary end point was a secondary hip procedure within 24 months of follow-up. Secondary end points included death, serious adverse events, hip-related complications, health-related quality of life, function, and overall health end points., Results: The primary end point occurred in 57 of 718 patients (7.9%) who were randomly assigned to total hip arthroplasty and 60 of 723 patients (8.3%) who were randomly assigned to hemiarthroplasty (hazard ratio, 0.95; 95% confidence interval [CI], 0.64 to 1.40; P = 0.79). Hip instability or dislocation occurred in 34 patients (4.7%) assigned to total hip arthroplasty and 17 patients (2.4%) assigned to hemiarthroplasty (hazard ratio, 2.00; 99% CI, 0.97 to 4.09). Function, as measured with the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score, pain score, stiffness score, and function score, modestly favored total hip arthroplasty over hemiarthroplasty. Mortality was similar in the two treatment groups (14.3% among the patients assigned to total hip arthroplasty and 13.1% among those assigned to hemiarthroplasty, P = 0.48). Serious adverse events occurred in 300 patients (41.8%) assigned to total hip arthroplasty and in 265 patients (36.7%) assigned to hemiarthroplasty., Conclusions: Among independently ambulating patients with displaced femoral neck fractures, the incidence of secondary procedures did not differ significantly between patients who were randomly assigned to undergo total hip arthroplasty and those who were assigned to undergo hemiarthroplasty, and total hip arthroplasty provided a clinically unimportant improvement over hemiarthroplasty in function and quality of life over 24 months. (Funded by the Canadian Institutes of Health Research and others; ClinicalTrials.gov number, NCT00556842.)., (Copyright © 2019 Massachusetts Medical Society.)

Objective: The purpose of this study was to compare perioperative hidden blood loss after hip hemiarthroplasty via the SuperPATH approach and the conventional posterior approach (the Moore approach)., Patients and Methods: From January 2015 to January 2017, 130 patients (80.7 ± 6.0 years) with displaced femoral neck fracture (Garden type III or IV) undergoing hip hemiarthroplasty were included in this study. As a non-randomisation study, Fifty-two patients (SuperPATH group) were operated using the SuperPATH approach, and 78 patients (Moore group) were operated with the conventional posterior approach (Moore approach). The demographic and relevant clinical information of the patients were collected. According to the combination formulas of Nadler, Gross and Sehat, the hidden blood loss (HBL) of each patient was calculated. Student's t-test for independent samples was used to compare the normally distributed variables and the Mann-Whitney U test was used to compare variables not following a normal distribution., Results: The visible blood loss (VBL) in the SuperPATH group was 123.7 ± 47.5 ml, the hidden blood loss (HBL) was 1084.1 ± 816.8 ml and the HBL% was 82.7 ± 16.5%. In the Moore group, the VBL was 303.6 ± 139.6 ml, the HBL was 700.2 ± 563.8 ml and the HBL% was 61.5 ± 23.8%. The patients in the SuperPATH group had more HBL and HBL% (P < 0.05). However, no significant difference was observed of total blood loss (TBL) between the two groups (P = 0.125)., Conclusions: HBL should not be ignored in patients who underwent hip hemiarthroplasty for displaced femoral neck fractures, as it is a significant portion of TBL. Compared with the conventional approach, the SuperPATH approach had a greater amount of HBL. A better understanding of HBL after hip hemiarthroplasty may help surgeons improve clinical assessment and ensure patient safety., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Clinicians have very limited options to improve fracture repair. Therefore, it is critical to develop a new clinically available therapeutic option to assist fracture repair biologically. We previously reported that the topical cutaneous application of carbon dioxide (CO 2 ) via a CO 2 absorption-enhancing hydrogel accelerates fracture repair in rats by increasing blood flow and angiogenesis and promoting endochondral ossification. The aim of this study was to assess the safety and efficacy of CO 2 therapy in patients with fractures., Methods: Patients with fractures of the femur and tibia were prospectively enrolled into this study with ethical approval and informed consent. The CO 2 absorption-enhancing hydrogel was applied to the fractured lower limbs of patients, and then 100% CO 2 was administered daily into a sealed space for 20 min over 4 weeks postoperatively. Safety was assessed based on vital signs, blood parameters, adverse events, and arterial and expired gas analyses. As the efficacy outcome, blood flow at the level of the fracture site and at a site 5 cm from the fracture in the affected limb was measured using a laser Doppler blood flow meter., Results: Nineteen patients were subjected to complete analysis. No adverse events were observed. Arterial and expired gas analyses revealed no adverse systemic effects including hypercapnia. The mean ratio of blood flow 20 min after CO 2 therapy compared with the pre-treatment level increased by approximately 2-fold in a time-dependent manner., Conclusions: The findings of the present study revealed that CO 2 therapy is safe to apply to human patients and that it can enhance blood flow in the fractured limbs., Trial Registration: This study has been registered in the UMIN Clinical Trials Registry (Registration number: UMIN000013641, Date of registration: July 1, 2014).

Background: Refractory femoral neck fractures cannot be anatomically reduced by closed traction reduction which may affect fracture healing. We evaluated the biomechanical effects of positive, negative, and anatomic reduction of various degrees of displacement in Pauwels I femoral neck fractures by a finite element analysis., Methods: Five reduction models of Pauwels type I femoral neck fracture were established using the Mimics 17.0 (Materialize, Leuven, Belgia) and Hypermesh 12.0 (Altair Engineering, Troy, MI, USA). According to the degree of fracture displacement, there were three models of positive support, an anatomic reduction model, and a negative 2 mm reduction model. Finite element analysis was conducted using the ABAQUS 6.9 software (Simulia, Suresnes, France). The von Mises stress distribution and the stress peak of internal fixation in different models, the displacement between fracture blocks, and the principal strain of the femoral neck cancellous bone model were recorded under the axial stress of 2100 N., Results: The peak von Mises stress on screw of each model was located at the thread of the screw tip. The peak von Mises stress was the lowest at the tip of the anatomic reduction model screw (261.2 MPa). In the positive 4 mm model, the von Mises stress peak was the highest (916.1 MPa). The anatomic reduction model showed the minimum displacement (0.388 mm) between fracture blocks. The maximum displacement was noted in the positive 4 mm model (0.838 mm). The displacement in the positive 3 mm model (0.721 mm) was smaller than that in the negative 2 mm model (0.786 mm). Among the five models, the strain area of the femoral neck cancellous bone was mainly concentrated around the screw hole, and the area around the screw hole could be easily cut., Conclusions: Compared with negative buttress for femoral neck fracture, positive buttress can provide better biomechanical stability. In Pauwel type I fracture of femoral neck, the range of positive buttress should be controlled below 3 mm as far as possible.

Controversy exists for the optimum method of surgical treatment for the 'fitter' elderly patient with a displaced intracapsular fracture. 105 patients were randomised to treatment with either a cemented polished tapered stem hemiarthroplasty or a cemented total hip arthroplasty (THR) with a cemented acetabular cup. All patients were followed up for a minimum of one year using a blinded assessment of functional outcome. Those patients treated with a THR had a tendency to a longer hospital stay and increased medical (12 versus 62) and surgical complications (4 versus 2) in comparison to those treated by hemiarthroplasty. Mean operative times (842 versus 52 min) and operative blood loss (335mls versus 244mls) were increased for THR. Final outcome measures of residual pain and regain of function were similar for both methods of treatment. We recommend that caution should be exercised regarding the increased promotion of THR for intracapsular hip fractures until further studies are completed., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: Both sliding hip screws (SHS) and cancellous screws are used in the surgical management of intracapsular femoral neck fracture. However, there is paucity of information as to which is the superior treatment modality. We performed this systematic review and meta-analysis study to compare the clinical outcomes of SHS and cancellous screws for the treatment of femoral neck fractures in adult patients., Methods: We searched PubMed, Scopus, Web of Science, and Cochrane CENTRAL, up to December 2017. Randomized controlled trials (RCTs) directly comparing the clinical outcomes of SHS and cancellous screws for femoral neck fractures were retrieved with no language or publication year restrictions. Data retrieved included operative details, nonunion rate, avascular necrosis, reoperation, infection and mortality, hip pain, functional hip scores, and medical complications. These were pooled as risk ratio or mean difference (MD) with their corresponding 95% confidence interval (CI). Heterogeneity was assessed by Chi-square test., Results: Ten RCTs involving 1934 patients were included in the final analysis. The pooled estimate showed that the SHS group was associated with more intraoperative blood loss (MD = 110.01 ml, 95% CI [52.42, 167.60], p = 0.00002) than the cancellous screws. There was no significant difference in terms of operative time, postoperative hip function, nonunion, avascular necrosis, reoperation rate, infection, fracture healing, hip pain, medical complications, and mortality rate., Conclusion: Based on our study, the cancellous screws group was associated with less intraoperative blood loss in comparison with the SHS group. No other significant differences were found between the two interventions.

Aims: The aim of this study was to determine if different patient groups have superior mobility regain following intertrochanteric hip fracture fixation with a cephomedullary nail compared to a sliding hip screw (SHS)., Patients and Methods: The present study is a subgroup analysis of patients which were enrolled into a randomized controlled trial which randomized 1000 patients with an intertrochanteric hip fracture to fixation with either a short cephomedullary nail (Targon® PF or PFT) or a SHS. In the present study the two treatment groups were dicotomised on the basis of six variables determined at the time of admission; age (<80; ≥80 years), sex, residence (admitted from own home; institutional care), mobility (mobility score ≥7 [good]; <7 [poor]), mental status (AMTS < 7 [cognitively impaired]; ≥7) and health status (ASA < 3; ≥3). The primary outcome measure was the difference between mobility score pre-fracture and mobility score during the year after hip fracture fixation., Results: Patients less than 80 years of age, those admitted from their own home, cognitively intact patients and patients who mobilised without assistance pre-fracture, recovered superior mobility when fracture fixation was performed with a nail compared to a SHS. Those patients admitted from institutional care, those with significant cognitive or mobility impairment at the time of the injury did not have any significantly improved benefit in mobility regain with a nail compared to a SHS., Conclusion: Fixation of an intertrochanteric hip fracture with a cephomedullary nail results in superior recovery of mobility for younger patients who prior to the injury were more mobile, cognitively intact and living at home., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Purpose: To assess the clinical outcomes of unipolar versus bipolar hemiarthroplasty for displaced intracapsular femoral neck fractures in older patients and to report whether bipolar implants yield better long-term functional results., Methods: We searched PubMed, Scopus, EBSCO, and Cochrane Library for relevant randomized clinical trials (RCTs) and observational studies, comparing unipolar and bipolar hemiarthroplasty. Data were extracted from eligible studies and pooled as relative risk (RR) or mean difference (MD) with corresponding 95% confidence intervals (CI) using RevMan software for Windows., Results: A total of 30 studies were included (13 RCTs and 17 observational studies). Analyses included 30,250 patients with a mean age of 79 years and mean follow-up time of 24.6 months. The overall pooled estimates showed that bipolar was superior to unipolar hemiarthroplasty in terms of hip function, range of motion and reoperation rate, but at the expense of longer operative time. In the longer term the unipolar group had higher rates of acetabular erosion compared to the bipolar group. There was no significant difference in terms of hip pain, implant related complications, intraoperative blood loss, mortality, six-minute walk times, medical outcomes, and hospital stay and subsequently cost., Conclusions: Bipolar hemiarthroplasty is associated with better range of motion, lower rates of acetabular erosion and lower reoperation rates compared to the unipolar hemiarthroplasty but at the expense of longer operative time. Both were similar in terms of mortality, and surgical or medical outcomes. Future large studies are recommended to compare both methods regarding the quality of life., (Crown Copyright © 2019. Published by Elsevier Ltd. All rights reserved.)

Background: This study aimed to analyze the effects of intracapsular pressure (IAP) on blood flow in the femur after a femoral neck fracture., Methods: Four simplified vascular models were used to measure the effect of vessel length on arterial blood flow in 10 New Zealand white rabbits. Ten models were evaluated under 10 different blood pressures., Findings: IAP increased following fracture of the femoral neck, and deformation had the greatest potential effect on blood flow in the retinacular artery. When blood pressure was fixed at 60 mm Hg, an increase in IAP caused a reduction in blood flow. When the IAP was relatively high (above 60 mm Hg), and higher than the blood pressure, blood flow continued to drop as intracapsular pressure increased. Shortening of blood vessels had no significant effect on blood supply. However, the p-value was uniformly significant (<0.05) when stretched and twisted blood vessels were compared with normal blood vessels., Interpretation: The results of computational fluid-structure interaction similarly indicated that a smaller blood vessel diameter and twisted blood vessels will result in decreased flow velocity when IAP increases. This study also revealed a close relationship between IAP and the hip joint's position and traction., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The supercapsular percutaneously-assisted total hip (SuperPATH®) approach was created by combining the percutaneous preparation of the acetabulum using the percutaneously-assisted total hip (PATH), femoral reaming, and broaching of superior capsulotomy (SuperCap) approach. This technique reported a low complication rate, excellent gait kinematics, low transfusion rate, a shorter length of hospital stay, and a high proportion of discharge from the hospital. As minimally invasive SuperPath approach is designed for both trauma and end-stage degenerative joint disease, we investigated if this technique and standard surgical tools can replace artificial femoral head in elderly patients with femoral neck fracture. We also tested if it has advantages over the traditional posterior approach., Methods: A prospective study was performed in 100 cases of eligible femoral neck fractures from May 01, 2015 to October 31, 2016. They were randomly divided into SuperPath and traditional group. The outcomes were evaluated using preoperative index, intraoperative data, and postoperative function data., Results: No significant difference was detected in the operation time between the two groups. Compared with the traditional group, SuperPath group had smaller incision length, less intraoperative bleeding, lower transfusion rate, and a shorter starting time of weight-bearing activity. Harris Hip Score, Barthel Index, and VAS for pain-level scores in the SuperPath group at 1-week follow-up intervals were significantly lower than the conventional group, but not significantly different at 3-month and 2-year follow-up post-operation., Conclusions: SuperPath approach for artificial femoral head replacement can reduce surgical injury due to smaller size of incision and accelerate weight-bearing activities post-operation to treat senile femoral neck fractures compared with traditional posterior approach surgeries., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Proximal humerus fractures which occur as a result of a fall on an outstretched arm are frequent among the elderly population. The necessity of stabilizing such fractures by surgical procedures is a controversial matter among surgeons. Validating a personalized FE analysis by ex-vivo experiments of humeri and mimicking such fractures by experiments is the first step along the path to determine the necessity of such surgeries., Methods: Four fresh frozen human humeri were loaded using a new simple experimental setting, so to fracture the humeri at the anatomical neck. Strains on humeri's surfaces predicted by the high order FE analyses (as in Dahan et al., 2016) were compared to the experimental observations to further enhance the validity of the FE analyses. A simplified yield criterion based on a linear elastic analysis and principal strains was used to predict the anatomical neck fracture as observed in the experiment., Findings: An excellent correlation between experimental measured and FE predicted strains was obtained (slope of 0.99 and R 2 =0.98). All humeri were fractured at the anatomical neck. The predicted yield load was within 10%-20% accuracy., Interpretation: High-order FE analyses reliably predict strains and yield loads in the humeri. Fractures induced by the experimental setting correspond to anatomical neck fractures noticed in practice and classified as AO C1.1-C1.3. Surgical neck fractures, which are most common in clinical practice, could not be realized in the proposed experiments, and a different experimental setting should be sought to obtain them ex-vivo., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Early mobilization following hip fracture surgery is of superior importance especially in elderly hip fracture patients. Reduced mobilization can result in complications and increased mortality. In this study a gait analysis was performed using force-measuring insoles. We hypothesized, that patients with femoral neck fractures treated with hip replacement surgery load the affected limb more compared to patients with pertrochanteric fractures treated with fracture fixation. All patients (> 65 years) treated for a femoral neck fracture with hip replacement or a pertrochanteric fracture, respectively using fracture fixation with intramedullary nailing, were consecutively included in this study. For gait analysis, specific insole forcesensors (Loadsol®) were inserted into the footwear. Five days after surgery gait analysis was performed with a defined walking distance and all patients were instructed to transpose full weight. 20 patients following hip replacement surgery and 27 patients following intramedullary nailing were included. The hip replacement group loaded the affected limb with an average of 74.01% (SD 13.6) of bodyweight, while the fracture fixation group loaded a significantly reduced average of 62.70% (SD 8.3; p = 0.002). The results of the present study indicate that patients suffering from pertrochanteric fractures following fracture fixation are struggling to fully load the affected leg compared to patients suffering from femoral neck fractures treated with hip replacement surgery. The focus of further studies should concentrate on alternative analgesia and verify the cause of the observed difference in order to facilitate early full weight bearing especially in hip fracture patients following fracture fixation. The results indicate that in elderly patients, the fracture pattern and thus the surgical approach lead to a different weight bearing pattern. The primary therapeutic goal for elderly patients must be early mobilization at full weight bearing., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Introduction: Femoral neck fractures are uncommon injuries in children, but the high incidence of long-term complications makes it important clinical entity. Early surgical treatment to achieve optimal results and to avoid a high rate of complications is widely advised. The purpose of this study was to retrospectively analyze the outcome of 8 children who sustained a femoral neck fracture., Patients and Methods: The patients (6 boys and 2 girls with an average age of 9.2 years) were treated within 24 h following admission to hospital by closed reduction and internal fixation. The type of fracture was distinguished according to Delbet's classification system. The outcome was analyzed using Ratliff's criteria, and a detailed record of complications was maintained., Results: According Delbet's classification system, there were 3 type I, 2 type II, 2 type III, and 1 type IV fractures. The average follow-up was 39.2 months (range 8-95). A satisfactory outcome was obtained in 6 (75%) children. Avascular necrosis was the most notable complication, which was reported in the 2 fair outcomes (25%)., Conclusions: Early and aggressive surgical treatment aimed at anatomical reduction result in a satisfactory outcome in pediatric femur neck fractures. Development of avascular necrosis is the main complication., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Osteosynthesis of femoral neck fractures is still associated with high complication rates. The novel method of biplane double-supported screw fixation offers better osteosynthesis stability by buttressing two of three medially diverging cannulated screws on the inferior neck cortex. Biomechanically, the most effective component of this fixation is the third, inferior obtuse screw, supported along considerable distance on both the inferior and posterior cortices of the femoral neck following its spiral anterior curve. Thus, biplane double-supported screw fixation achieves greater inferoposterior cortical support of the implants, allowing immediate full weight bearing for patients older than 55 years. Although the method has been recently communicated, some important surgical aspects still remain to be discussed. This report aims at describing a detailed and modified surgical technique and providing criteria and recommendations for its successful application according to the clinical experience over more than 9 years. LEVEL OF EVIDENCE:: Level V, expert evidence.

Background: There is limited information on the complications and costs of conversion THA after hemiarthroplasty for femoral neck fractures. Previous studies have found that patients undergoing conversion THA experience higher risk complications, but it has been difficult to quantify the risk because of small sample sizes and a lack of comparison groups. Therefore, we compared the complications of patients undergoing conversion THA with strictly matched patients undergoing primary and revision THA., Questions/purposes: (1) What are the risks of complications, dislocations, reoperations, revisions and periprosthetic fractures after conversion THA compared with primary and revision THA and how has this effect changed over time? (2) What are the length of hospital stay and hospital costs for conversion THA, primary THA, and revision THA?, Methods: Using a longitudinally maintained total joint registry, we identified 389 patients who were treated with conversion THA after hemiarthroplasty for femoral neck fractures between 1985 and 2014. The conversion THA cohort was 1:2 matched on age, sex, and year of surgery to 778 patients undergoing primary THA and 778 patients undergoing revision THA. The proportion of patients having at least 5-year followup was 73% in those who underwent conversion THA, 77% in those who underwent primary THA, and 76% in those who underwent revision THA. We observed a significant calendar year effect, and therefore, compared the three groups across two separate time periods: 1985 to 1999 and 2000 to 2014. We ascertained complications, dislocations, reoperations, revisions and periprosthetic fractures from the total joint registry. Cost analysis was performed using a bottom-up, microcosting methodology for procedures between 2003 and 2014., Results: Patients who converted to THA between 1985 and 1999 had a higher risk of complications (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.7-3.1; p < 0.001), dislocations (HR, 2.3; 95% CI, 1.3-4.2; p = 0.007), reoperations (HR, 1.7; 95% CI, 1.2-2.5, p = 0.005), and periprosthetic fractures (HR, 3.8; 95% CI, 2.2-6.6; p < 0.001) compared with primary THA. However, conversion THAs during the 1985 to 1999 time period had a lower risk of reoperations (HR, 0.7; 95% CI, 0.5-1.0; p = 0.037), revisions (HR, 0.6; 95% CI, 0.5-0.9; p = 0.014), and periprosthetic fractures (HR, 0.6; 95% CI, 0.4-0.9; p = 0.007) compared with revision THA. The risk differences across the three groups were more pronounced after 2000, particularly when comparing conversion THA patients with revision THA. Conversion THA patients had a higher risk of reoperations (HR, 1.9; 95% CI, 1.0-3.4; p = 0.041) and periprosthetic fractures (HR, 1.7; 95% CI, 1.0-2.9; p = 0.036) compared with revision THA, but there were no differences in the complication risk (HR, 1.4; 95% CI, 0.9-2.1; p = 0.120), dislocations (HR, 1.5; 95% CI, 0.7-3.2; p = 0.274), and revisions (HR, 1.4; 95% CI, 0.7-3.0; p = 0.373). Length of stay for conversion THA was longer than primary THA (4.7 versus 4.0 days; p = 0.012), but there was no difference compared with revision THA (4.7 versus 4.5 days; p = 0.484). Similarly, total inpatient costs for conversion THA were higher than primary THA (USD 22,662 versus USD 18,694; p < 0.001), but there was no difference compared with revision THA (USD 22,662 versus USD 22,071; p = 0.564)., Conclusions: Over the 30 years of the study, conversion THA has remained a higher risk procedure in terms of reoperation compared with primary THA, and over time, it also has become higher risk compared with revision THA. Surgeons should approach conversion THA as a challenging procedure, and patients undergoing this procedure should be counseled about the elevated risks. Furthermore, hospitals should seek appropriate reimbursement for these cases., Level of Evidence: Level III, therapeutic study.

Purpose: The medical morbidity and mortality associated with neck of femur fractures is well-documented, whereas there is limited data for patient-reported outcomes. The aim of this study was to characterize the impact of neck of femur fractures on activities of daily living and patient-reported health-related quality of life., Methods: Design and participants: Multicentric prospective cohort study. Consecutive sample patients with fragility hip fracture over 50 years old admitted in 48 hospitals in Spain., Outcomes: daily living activity function (Barthel Index) and health-related quality of life (EQ-5D) pre-fracture, admission to hospital and at 1- and 4-month follow-up post-fracture., Statistics: Barthel and EQ-5D over time are described as mean (SD) and median (interquartile range)., Results: A total of 997 patients were recruited at baseline with 4-month outcomes available for, and 856 patients (89.5%). Barthel Index fell from 78.77 (23.75) at baseline to 43.62 (19.86) on admission to hospital with the fracture. Scores partially recovered to 54.89 (25.40) and 64.09 (21.35) at 1- and 4-month post-fracture, respectively. EQ-5D fell from a median of 0.75 (0.47-0.91) to - 0.01 (- 0.03 to 0.51) on admission. Partial recovery was observed again to (0.51 (- 0.06 to 0.67)) and (0.60 (0.10 to 0.80)) at 1- and 4-month post-fracture, respectively., Conclusions: Hip fracture results in a large decline in the ability to perform activities of daily living and patient-reported health-related quality of life with only partial recovery amongst survivors 4-month post-fracture.

Introduction: The purpose of this study was to determine factors that affect the early failure of femoral neck fracture healing after internal fixation with a dynamic locking plate implant., Patients and Methods: Retrospective analysis of all cases of femoral neck fracture (FNF) primarily treated with dynamic locking plate implant from 04/2014 to 04/2017 with a minimum of 6 month follow-up. For the purpose of the study age, sex and time from admission to surgery were retrieved from the hospital medical database. Patient's pre- and postoperative hip radiographs were reviewed by the authors. Radiographically detected fracture healing failure (non-union and screw cut-out) was recorded., Results: For the period of the study, there were 77 consecutive FNF (76 patients) treated with the dynamic locking plate implant. Eight (10%) patients were lost to follow-up, 13 (17%) patients died within 6 months after surgery. Healing failure was identified in 23 (41%) of remaining 56 cases. Three of four (75% failure rate) failures were observed in cases with fair-quality reduction and two of two (100% failure rate) failures were noticed in the case of none telescoping screw located within subchondral bone. Multiple logistic regression showed an increased risk of fracture failure in cases with at least one completely collapsed telescoping screw (OR = 73.2; 95% CI 9.4-568.5, p < 0.01), while telescoping screws' location around centre of the femoral head reduces the risk of failure (OR = 14.7; 95% CI 1.6-135.1, p = 0.02)., Conclusion: In our group of patients, fracture healing failure of the FNF treated with dynamic locking plate reached 41%. This high failure rate was associated with poor fracture reduction, not subchondrally and centrally placed telescoping screws and in the case of complete collapse on at least one of the telescoping screws.

Objective: To investigate the biomechanical effects of reduction quality on patients after femoral neck fracture internal fixation., Methods: The data of individual patients with femoral neck fractures were reviewed. Data for patients with simple unilateral femoral neck fractures whose reduction quality was evaluated as good by hip X-ray films after internal fixation were collected from January 2013 to January 2017. The CT data of the patients was used to reconstruct 3D models of the femur and the screw. The spatial displacement after the operation of femoral neck fracture was measured, which included the displacement of the deepest portion of the femoral head fovea, the displacement of the center of the femoral head, and the rotational angle. The cases were followed up by telephone consultation and clinical review to determine whether the osteonecrosis of the femoral head occurred. Follow-up time should be more than 18 months after surgery. The cases were grouped according to the results into an osteonecrosis of the femoral head group and a non-osteonecrosis of the femoral head group. Finally, the differences in postoperative spatial displacement between the two groups were compared and analyzed. In addition, a mechanical analysis of femoral force during gait was performed via finite element analysis., Results: Data for 241 patients with femoral neck fractures who were treated with closed reduction and internal fixation were collected. 3D measurement showed the average displacement value, including the center of the femoral head (5.90 ± 3.4 mm), the deepest portion of the femoral head fovea (9.32 ± 4.8 mm), and the rotational angle (16.1° ± 9.4°). After telephone consultation and clinical review, osteonecrosis of the femoral head was diagnosed in 28 (11.62%) of the patients. In the osteonecrosis of the femoral head (ONFH) group, the displacement of the deepest portion of the femoral head fovea was 10.92 ± 9.18 mm; the displacement was 8.86 ± 6.29 mm in the non-ONFH group. The displacement of the center of the femoral head in the ONFH group was 7.575 ± 5.69 mm and 5.31 ± 4.05 mm in non-ONFH group. The rotational angle was 20.11° ± 10.27° in the ONFH group and 14.19° ± 11.09° in the non-ONFH group. The statistical analysis showed that the postoperative spatial displacements, including the displacement of the deepest portion of the femoral head fovea, the displacement of the center of the femoral head, and the rotational angle between the two groups, had statistical differences. Finite element analysis showed that as the spatial displacement increased, the stress, the displacement, and the equivalent strain of the proximal femur also increased., Conclusion: Poor reduction quality after femoral neck fracture is a risk factor for re-fracture and femoral head necrosis, and the measurement method of this study can be used to predict the occurrence of femoral head necrosis early after femoral neck fracture., (© 2019 The Authors. Orthopaedic Surgery published by Chinese Orthopaedic Association and John Wiley & Sons Australia, Ltd.)

Objectives: To report on the final displacement after in situ percutaneous pinning for Garden type 1 and 2 fractures in height, femoral neck fracture collapse, and loss of offset., Design: Retrospectively reviewed case series., Setting: Three Academic Medical Centers. Boston University Medical Center (Level 1 Trauma Center), Lahey Hospital and Medical Center (Level 2 Trauma Center), and Geisinger Medical Center (level 2 Trauma Center)., Patients/participants: One hundred thirty skeletally mature patients with 130 fractures (78 garden 1 and 52 garden 2) who were treated between January 2000 and January 2014 at participating hospitals with percutaneous pinning with a cannulated screw system to successful union after sustaining an intracapsular femoral neck fracture without complete displacement., Intervention: In situ percutaneous pinning with 3 cannulated, partially threaded screws in an inverted triangle orientation., Main Outcome Measurements: Femoral neck fracture collapse (mm), femoral height shortening (mm), and femoral offset shortening (mm)., Results: A total of 130 patients (81F, 49M), average age 72 years, sustained 78 Garden 1 and 52 Garden 2 femoral neck fractures. Maximal collapse occurred in the plane of the femoral neck. Thirty-three of 78 (42%) Garden 1 fractures and 33/52 (63%) Garden 2 fractures demonstrated >10 mm fracture collapse. The range of displacements was 0-39 mm as measured along the plane of the femoral neck., Conclusions: Garden 1 fractures collapse less frequently than Garden 2 fractures, but both have high rates of fracture collapse when treated to union with in situ percutaneous pin fixation., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: The aim of this study was to investigate the postoperative outcomes of cementless Total hip arthroplasty (THA) following failed internal fixation for femoral neck and intertrochanteric fractures., Method: Ninety-six cementless THAs for failed internal fixation after femoral neck fracture (59, group I) and intertrochanteric fracture (37, group II) with a minimum follow-up of 3 years were analyzed. Clinical and radiologic evaluations were performed on all patients., Results: The intraoperative blood loss and operating time were significantly increased in group II (p = 0.001, p = 0.001, respectively). Harris hip score at last follow-up was significantly improved in group I (p = 0.007) but, there were no differences in hospital stay, Koval score at last follow-up, and perioperative complications between both groups. Long femoral stems for diaphyseal fitting were frequently used in group II (32/37, 86%) (p = 0.001). Radiographically, none of the acetabular cups showed evidence of migration, loosening. All cases showed stable fixation of the femoral stem at last follow-up., Conclusions: Outcomes of cementless THA following failed internal fixation for femoral neck and intertrochanteric fractures were satisfactory; increased intraoperative blood loss, operating time, and requirement of long femoral stem should be considered in the latter type of fracture., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Introduction: Hip fractures are common in the elderly population. It is currently believed that patients can expect to lose a level of mobility following a hip fracture. The aim of this study was to compare the pre- and post-treatment mobility of patients treated in our institution who had suffered a fracture neck of femur and identify the factors that could predict pre-operatively those patients who would suffer a deterioration in mobility after treatment., Methods: Patients admitted to a large UK teaching hospital with a surgically treated neck of femur fracture were included between 2 April 2011 and 31 March 2014. Patient's mobility was assessed on admission and at 1 year following surgery., Results: There were a total of 615 patients alive at 1 year. There were 142 males and 473 females with a mean age of 82.1 (range 47-100). On admission, 338 (55.0%) mobilised independently 52.2% had no change in their pre-fracture mobility at 1 year following their treatment. Age, a lower AMTS, a higher ASA and living in residential care were significant risk factors for not regaining their pre-fracture mobility. Sex and type of fracture were not associated with change in mobility., Conclusion: It is commonly stated that patients lose one level of mobility following a hip fracture. This case series demonstrates that over 50% of patients can expect to have the same level of mobility at 1 year post-surgery as they did previously.

Fractures of the femoral neck can occur in young healthy individuals due to high loads occurring during motor vehicle accidents, impacts, or falls. Failure forces are lower if impacts occur sideways onto the greater trochanter as compared with vertical loading of the hip. Bone density, bone geometry, and thickness of cortical bone at the femoral neck contribute to its mechanical strength. Femoral neck fractures in young adults require accurate reduction and stable internal fixation. The available techniques for fracture fixation at the femoral neck (cannulated screws, hip screw systems, proximal femur plates, and cephallomedullary nails) are reviewed with respect to their competence to provide biomechanical stability. Mechanically unstable fractures require a load-bearing implant, such as hip screws, with antirotational screws or intramedullary nails. Subcapital or transcervical fracture patterns and noncomminuted fractures enable load sharing and can be securely fixed with cannulated screws or solitary hip screw systems without compromising fixation stability.

Background: Postmenopausal osteoporosis develops due to a deficiency of estrogen that causes a decrease in bone mass and changes in the macro- and micro-architectural structure of the bone, leading to the loss of mechanical strength and an increased risk of fracture. Although the assessment of bone mineral density (BMD) has been widely used as a gold standard for diagnostic screening of bone fracture risks, it accounts for only a part of the variation in bone fragility; thus, it is necessary to consider other determinants of bone strength. Therefore, we aimed to comprehensively evaluate the architectural changes of the bone that influence bone fracture strength, together with the different sensitivities of cortical and trabecular bone in response to ovariectomy (OVX)., Methods: Bone morphology parameters were separately analyzed both in cortical and in trabecular bones, at distal-metaphysis, and mid-diaphysis of OVX rat femurs. Three-point bending test was performed at mid-diaphysis of the femurs. Correlation of OVX-induced changes of morphological parameters with breaking force was analyzed using Pearson's correlation coefficient., Results: OVX resulted in a decline in the bone volume of distal-metaphysis trabecular bone, but an increase in distal-metaphysis and mid-diaphysis cortical bone volume. Tissue mineral density (TMD) remained unchanged in both the trabecular and cortical bone of the distal metaphysis but decreased in cortical bone of the mid-diaphysis. The OVX significantly increased the breaking force at mid-diaphysis of the femurs., Conclusions: OVX decreased the trabecular bone volume of the distal-metaphysis and increased the cortical bone volume of the distal-metaphysis and mid-diaphysis. Despite the reduction in TMD and increased cortical porosity, bone fracture strength increased in the mid-diaphysis after OVX. These results indicate that analyzing a single factor, i.e., BMD, is not sufficient to predict the absolute fracture risk of the bone, as OVX-induced bone response vary, depending on the bone type and location. Our results strongly support the necessity of analyzing bone micro-architecture and site specificity to clarify the true etiology of osteoporosis in a clinical setting.

Background: Nearly 18,000 individuals suffer from hip fracture in Sweden each year. The choice in operation method for femoral neck fractures has changed over the years as well as the overall management. Functional outcome after hip fracture is affected by several factors and the overall functional level for old people in Sweden has improved over the last decades., Objective: To describe and analyse the functional outcome and choice of operation method for hip fracture patients between 1988 and 2012., Patients and Methods: All patients with cervical or trochanteric hip fracture treated at Lund University Hospital from 1988 until 2012 were collected from the National Quality Register for hip fracture patients, RIKSHÖFT. Patients younger than 50 years and those with pathological fractures were excluded. Data regarding patient characteristics, fracture type, operation method and housing, walking ability and use of walk aids prefracture and at 4-months follow-up was retrieved and analysed., Results: For this study 8723 patients were included with a mean age of 81.6 (men 79.3, women 82.5). The mean age significantly increased over the period studied. Sliding hip screw dominates as method of choice for the trochanteric fractures. For the cervical fractures there is a clear shift from osteosynthesis to arthroplasty. There is a significant decrease in functional outcome at follow-up compared to prefracture. No significant trend change can be seen over 25 years. Functional outcome are worse for the patients with trochanteric fracture., Conclusion: Although there have been changes in operation methods for hip fractures and the management has developed, our study does not show any effect on functional outcome over a 25-year period. The medical condition of these patients with increasing age seems to counteract efforts to improve the care., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Introduction: Femoral neck fractures (FNF) after internal fixation of trochanteric fractures (AIFTF) with the implant in situ (WIIS) are uncommon. Publications of FNFAIFTFWIIS are rare. The purpose of this systematic review of the literature is to report on the frequency, risk factors, mechanisms, clinical presentation, diagnostic and therapeutic modalities, outcomes and the eventual prevention of this complication., Materials and Methods: A comprehensive review of the literature was undertaken using the PRISMA guidelines with no language restriction. Case reports of FNFAIFTFWIIS and series of trochanteric fractures (TF) with this complication in adults published between inception of journals to May 2018 were eligible for inclusion. Cases with fractures in pathological bone, undergoing treatment with hip replacement, or after partial or total implant removal were excluded. Relevant information was divided in two parts. Part I included the analysis of cases of FNFAIFTFWIIS, with the objective of establishing the eventual risk factors, mechanisms, diagnostic, treatment modalities, and outcomes. Part II analyzed series of TFs with implants in situ which included cases of FNFs for assessing the incidence of FNFs in this condition., Results: Overall 77 publications with 104 cases of FNFAIFTFWIIS met the inclusion criteria. The median incidence of this complication was 0,43%. The mean age was 80 years (range, 42-96).The prevalent factors for FNFAIFTFWIIS were osteoporosis, and the presence of the implant in the femoral neck and head. A short nail or screw with the tip far from the subchondral bone was of influence as a stress riser factor, but not prevalent because in two thirds of the cases the FNF occurred when the implant was introduced up to the subchondral bone. Other risk factors analysed included varus reduction or nonunion of the TF, and the breakage of the hip screw, which modify the forces exerted over the femoral neck, and may contribute to the FNF. The FNFs were spontaneous, i.e. not related to trauma or fall, in more than two thirds of the cases., Conclusion: The etiology of FNFAIFTFWII should be considered multifactorial. The frequency seems low. Although a subchondral positioning of the hip screw might diminish the incidence of FNFS, a correct surgical technique does not preclude a FNFAIFTFWIIS, and in fact the incidence of this complication was higher in these correctly treated patients. FNFAIFTFWIIS is a fragility fracture and adequate management of systemic osteoporosis should be targeted as a main factor of prevention., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background and Purpose: The recommended treatment of displaced femoral neck fractures (FNF) in patients younger than 70 years of age is fracture reduction and internal fixation (IF). The incidence of re-operation due to nonunion (NU) or avascular necrosis (AVN) has been reported to be between 20-30%. Knowledge of possible predisposing factors needs to be elucidated. The primary aim of this study was to identify factors associated with a major re-operation due to NU or AVN in patients <70 years with a displaced FNF treated with IF., Patients and Methods: 128 patients, 20-69 years with a FNF treated with IF. Follow up included radiographic and clinical examination at 4, 12 and 24 months. Logistic regression analysis was used to identify factors associated with re-operation due to NU or AVN., Results: The re-operation rate due to NU or AVN was 6%, 16% and 28% at 4, 12 and 24 months respectively. Patients with low BMD was more likely to be re-operated than those with normal BMD, OR 5.5, CI (95%) 1.15-26.8, and those with a high alcohol consumption had 3.2 times higher odds to be re-operated due to NU or AVN, CI (95%) 1.16-8.76., Interpretation: In more than two thirds (83/120) of the patients the fracture healed after one operation. Moreover, a low BMD and high alcohol consumption were related to a major re-operation. These results suggest that only age as a sole variable for choosing the type of surgical treatment may not be rational., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Purpose: The aim of our study is to compare the mechanical resistance of two screw configurations in fixating type II Pauwels femoral neck fractures., Methods: Fifteen synthetic models of femur bones in young adults were divided into three equal groups: intact (G1), models with fixation of a 5.0-mm failure zone created in the posterior cortex of the femoral neck using an L-shaped screw arrangement (G2, n = 5), and models with an identical failure zone fixated using an inverted triangle assembly (G3, n = 5). Model strength (axial loading) and rotational deviation of the fragments were load-tested until a 5.0-mm displacement was reached (step 1) and then until failure, here considered as 10.0 mm displacement in G2 and G3 or femoral neck fracture in G1 (step 2)., Results: In step 1, the mean resistance in G1 was 1593 N (standard deviation [SD] of 62 N); this value in G2 was 1261 N (SD 49 N) and in G3 was 1074 N (SD 153 N). During step 2, the value for G1 was 2247 N (SD 84 N), for G2 was 1895 N (SD 69 N), and for G3 was 1523 N (SD 280 N). G3 (the inverted triangle assembly) showed a significantly lower maximum load than the group using the L-shaped assembly (G2) and the control group (G1), which was significant using Kruskal-Wallis analysis of variance (p = 0.002)., Conclusion: Under test conditions in synthetic bone, fixation using a L-shaped screw assembly provides greater mechanical resistance than an inverted triangle assembly.