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Background: Management of scaphoid nonunions with bone loss varies substantially. Commonly, internal fixation consists of a single headless compression screw. Recently, some authors have reported on the theoretical benefits of dual-screw fixation. We hypothesized that using 2 headless compression screws would impart improved stiffness over a single-screw construct. Methods: Using a cadaveric model, we compared biomechanical characteristics of a single tapered 3.5- to 3.6-mm headless compression screw with 2 tapered 2.5- to 2.8-mm headless compression screws in a scaphoid waist nonunion model. The primary outcome measurement was construct stiffness. Secondary outcome measurements included load at 1 and 2 mm of displacement, load to failure for each specimen, and qualitative assessment of mode of failure. Results: Stiffness during load to failure was not significantly different between single- and double-screw configurations ( P = .8). Load to failure demonstrated no statistically significant difference between single- and double-screw configurations. Using a qualitative assessment, the double-screw construct maintained rotational stability more than the single-screw construct ( P = .029). Conclusions: Single- and double-screw fixation constructs in a cadaveric scaphoid nonunion model demonstrate similar construct stiffness, load to failure, and load to 1- and 2-mm displacement. Modes of failure may differ between constructs and represent an area for further study. The theoretical benefit of dual-screw fixation should be weighed against the morphologic limitations to placing 2 screws in a scaphoid nonunion.

A female in her 40s was referred to our institution having undergone right-sided percutaneous sacroiliac (SI) screw fixation of a pelvic fracture 28 years prior, following a road traffic collision. She had made a complete recovery and was engaging in an active lifestyle. She presented to her local

Background It is recommended to have 6 bicortical screws for plate fixation of long bone fractures; however, many metacarpal fractures do not allow 6 screws due to size limitations and proximity of crucial anatomical structures. The purpose of this biomechanical study was to determine whether the mechanical properties of a 4-screw nonlocking construct are noninferior to those of a 6-screw nonlocking construct. Methods Metacarpal sawbones were used to simulate a midshaft, transverse fracture. Nonlocking bicortical screws were placed in the 6-hole plate, and the metacarpals were randomly assigned to 2 equal study groups: (1) 4 screws, 2 on either side of the fracture (4S); and (2) 6 screws, 3 on either side of the fracture (6S). The metacarpals were tested in a cyclic loading mode and load to failure in a cantilever bending mode. Results Maximum deflection was significantly higher for 4S compared with 6S. Cyclic root mean square (RMS) was also significantly greater for 4S at 70 and 100 N. There were no statistically significant differences observed between the 2 constructs for maximum bending load, bending stiffness, and cyclic RMS at 40 N. The maximum bending load in 4S and 6S was 245.6 ± 37.9 N and 230.8 ± 41.9 N, respectively; 4S was noninferior and not superior to 6S. Noninferiority testing was inconclusive for bending stiffness. Conclusions A 4-screw bicortical nonlocking construct is noninferior to a 6-screw bicortical nonlocking construct for fixation of metacarpal fractures, which may be advantageous to minimize disruption of soft tissues while maintaining sufficient construct stability.

Since the atlantoaxial region have critical neurovascular anatomy and limited bone surface for fusion, the application and choice of salvage fixation techniques are highly important. To discuss alternative posterior atlantoaxial fixation surgery techniques.We retrospectively surgical records of 22 patients that posterior atlantoaxial fixation techniques were applied.The patients included 11 males and 11 females (mean age: 65.7 years). The fracture type that caused instability is type 2 odontoid fractures (22). In six of these patients alternative stabilization techniques were applied due to anatomical variations, huge venous bleeding and iatrogenic trauma of the screw entry points during surgery.Owing to anatomical variations, intraoperative challenges, and/or instrumentation failures, performing alternative surgical fixation technique is an important factor that affects the success of stabilization of the atlantoaxial region. Knowledge of salvage techniques especially during the learning curve is vitally important. Surgeons should adapt to intraoperative surgical challenges as required.

Statement of problem Computer-aided design and computer-aided manufacturing (CAD-CAM) methodologies allow the fabrication of custom dental implant abutments with a variety of materials and techniques. Studies on the mechanical strength of such components and the wear induced at their coupling interface during mechanical cycling are sparse. Purpose The purpose of this in vitro study was to measure the wear patterns at the hexagonal platform of dental implants induced by the installation and mechanical cycling of custom abutments fabricated by using 4 different CAD-CAM methods and to determine the compressive static resistance of the implant-abutment combinations. Material and methods A CAD software program was used to design a custom abutment for a single-unit screw-retained external hexagon dental implant crown. The same design file was used to manufacture with 4 CAM methods (N=40): milling and sintering of zirconium dioxide (ZO), cobalt-chromium (Co-Cr) sintered by selective laser melting (SLM), fully sintered machined Co-Cr alloy (MM), and machined and sintered agglutinated Co-Cr alloy powder (AM). Prefabricated titanium abutments were used as a control (TI). Each abutment was installed onto a dental implant (4.1×11 mm), and the specimens were mechanically aged (1 million cycles, 2 Hz, 100N, 37 °C). After mechanical cycling, the hexagonal connection of the dental implants was examined with a scanning electron microscope (SEM), and unused dental implants (NI) were examined as a control (n=10). The images were analyzed with a software program to quantify the areas that showed wear. The implant-abutment combinations were reassembled and submitted to a compression test (1mm/min) with a universal testing machine. The data obtained were submitted to 1-way ANOVA (α=.05). Results The mean ±standard deviation fracture load (N) of the specimens of each group were 1005 ±187 (ZO), 1074 ±123 (SLM), 1033 ±109 (MM), 1019 ±149 (AM), and 923 ±129 (TI). These values were statistically similar (P=.213). The mean ±standard deviation wear of the implants in squared-pixels were 1.1 ±0.38×105 (ZO), 2.0 ±0.29×105 (SLM), 1.0 ±0.38×105 (MM), 1.1 ±0.27×105 (AM), 1.1 ±0.33×105 (TI), and 0.51 ±0.29×105 (NI). The results indicated that, although significantly higher than those in in the control group (NI), the wear values found in the groups TI, ZO, MM, and AM were significantly lower than in the SLM group (P Conclusions The CAD-CAM abutments presented the same mechanical fracture load and wear measurements as the TI group, except for the SLM material, which showed increased wear. The failure mode from the load bearing test was the fracture of the abutments for the ZO group. The implants permanently deformed or fractured for the metal abutment groups.

Evidence to validate the routine use of angled screw-channel abutments in the anterior maxilla is sparse. If properly planned, they might provide surgical and prosthetic benefits.The purpose of this observational study was to determine the prevalence of digitally placed implants in the anterior maxilla that would allow screw-retained implant-supported restorations with either a straight or an angled screw-channel abutment.Two hundred cone beam computed tomography (CBCT) scans met the inclusion criteria for retrospective analysis and digital implant planning. Virtual implants were planned for randomly selected anterior maxillary teeth by using the anatomic crown and root position. Virtual abutments of varying angulation were attached to the implants to determine the ability to screw retain a restoration with either a straight or an angled screw-channel abutment.One hundred fifty-two (76%) sites required an angled screw-channel abutment to enable screw retention. Forty-eight (24%) sites allowed screw retention with a straight abutment. The percentage of implants requiring angled or straight abutments varied significantly among anterior teeth (P.005). One hundred nine (71.7%) angled screw-channel abutment sites required a 5-degree abutment, 41 (26.9%) required a 10-degree abutment, and 2 (1.3%) required a 15-degree abutment. Among the anterior teeth, lateral incisors presented a greater need for angled screw-channel abutments. None of the implants in the present study needed cement-retained restorations.Angled abutments allowed for screw-retained restorations on digitally planned implants in the anterior maxilla. The required angular correction to a screw-retained restoration was ≤15 degrees. Screw-retained restorations were frequently achievable (76%) with the use of angled screw-channel abutments or with straight abutments (24%), and lateral incisors presented a greater need for angled screw-channel abutments.

OBJECTIVE To evaluate S1 transsacral (TS) corridors on reformatted and non-reformatted computed tomography (CT) images to determine which most reliably identifies narrow corridors. DESIGN Retrospective cohort. SETTING Level 1 trauma center. PATIENTS 245 patients with operative pelvic ring injuries. INTERVENTION CT scan review. MAIN OUTCOME MEASUREMENTS Preoperative CT scans were evaluated to determine the width of the S1 TS corridor on standard axial non-reformatted (ANR), axial reformatted (AR), and coronal reformatted (CR) images. Sensitivity and specificity of each format to detect a narrow corridor (

Tibiofibular injury repair of ankle fractures may result in over-compression when performed via a partially threaded screw depending on its placed level. We aimed to examine the relationship between the screw level relative to the tibiotalar joint and syndesmosis malreduction in postoperative radiographs of ankle fractures treated with partially threaded screws. We retrospectively analyzed 129 patients who underwent surgery due to lateral malleolar fractures between 2011 and 2019. We measured the distance between the screw and the tibiotalar joint and stratified the patients per their screw level as either trans-syndesmotic or suprasyndesmotic. According to Lauge-Hansen, 83 cases were supination-external rotation type (64.3%), and the remaining were pronation-external rotation type (35.7%) injuries. We found postoperative syndesmosis malreduction in 20 cases (15.5%). Eight (6.2%) cases had medial clear space mismatch. As the distance of the screw to the joint increased, postoperative medial clear space values increased (rho: 0.190, p = .031). The relationship between postoperative syndesmosis mismatch and the level of the syndesmotic screw was statistically significant (p = .044). In syndesmosis repair with a partially threaded screw, as the distance of the screw from the joint increases, the over-compression caused by the screw may cause an increase in postoperative syndesmotic malreduction rates.

Maintaining reduction after syndesmotic injury is crucial to patient function; however, malreduction remains common. Flexible suture button fixation may allow more physiologic motion of the syndesmosis compared with rigid screw fixation. Conventional syndesmotic imaging fails to account for physiologic syndesmotic motion with ankle range of motion (ROM), providing misleading results. Four-dimensional computerized tomography (4DCT) can image joints through a dynamic ROM. Our purpose was to compare syndesmotic motion after rigid and flexible fixation using 4DCT.We analyzed 13 patients with syndesmotic injury who were randomized to receive rigid (n = 7) or flexible (n = 6) fixation. Patients underwent bilateral ankle 4DCT while moving between ankle dorsiflexion and plantar flexion. Measures of syndesmotic position and rotation were extracted from 4DCT to determine syndesmotic motion as a function of ankle ROM.Uninjured ankles demonstrated significant decreases in syndesmotic width of 1.0 mm with ankle plantar flexion (SD = 0.6 mm, P0.01). Initial rigid fixation demonstrated reduced motion compared with uninjured ankles in 4 of 5 measures (P0.01) despite all patients in the rigid fixation group having removed, loose, or broken screws by the time of imaging. Rigid fixation led to less motion than flexible fixation in 3 measures (P = 0.02-0.04). There were no observed differences in syndesmotic position or motion between flexible fixation and uninjured ankles.Despite the loss of fixation in all subjects in the rigid fixation group, initial rigid fixation led to significantly reduced syndesmotic motion. Flexible fixation recreated more physiologic motion compared with rigid fixation and may be used to reduce rates of syndesmotic malreduction.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background Achieving medial support for proximal humeral fractures (PHFs) by regular calcar screw positioning is challenging when the humeral head is small or locking plates are placed distally, as there are unable inserted calcar screws into the humeral head. We aimed to investigate the suitability of the two strategies, slotting calcar screw (SCS) and off-axis calcar screw (OCS) to achieve medial support for PHFs. Methods Regular calcar screw (RCS), SCS, OCS, and non-calcar screw (NCS) were tested via mechanical experiments and finite element analysis (FEA), using synthetic bones for biomechanical comparisons. All PHFs treated in our hospital from March 2017 to March 2019 were reviewed. The patients were divided into three groups based on the calcar screw fixation: RCS, SCS, and OCS. The postoperative varus collapse (neck-shaft angle changed to less than 120°) and Disabilities of the Arm, Shoulder and Hand (DASH) scores were recorded. Results The properties of RCS, SCS, and OCS against the torsion and varus force were superior to those of NCS, while the stiffness of SCS, OCS, and RCS were similar. FEA predicted lower peri-screw strains in the OCS and SCS than in the RCS, indicating a lower risk of cut-out. Patients (n = 125; 75 female, 50 male) aged 55.9 ± 13.0 years were evaluated. Compared with the RCS (5/55), varus collapse incidences were not significantly higher following SCS (0/29, p = 0.094) or OCS (3/41, p = 0.756), and neither were DASH scores (p = 0.867 and 0.736, respectively). Conclusions This study is a preliminary study demonstrating that the SCS and OCS fixation strategies could be useful alternatives when regular calcar fixation is not possible using the plate at hand.

Study Design: Retrospective study.Objective: To investigate the long-term clinical outcome and incidence of iliac screw-related complications in patients with adult spinal deformity (ASD).Summary of Background Data: Rigid lumbosacral fixation is crucial to achieve optimal global alignment and successful long-term clinical outcomes.Methods: The data of eligible patients with ASD who underwent spinopelvic fixation using bilateral iliac screws with at least 5-year follow-up periods were retrospectively analyzed. Iliac screw loosening and rod breakage between the S1 and iliac (S1/IL) screws were defined as distal instability (DI). Demographic data, health-related quality of life scores, and spinopelvic parameters in the DI group were compared with those in the non-DI group. Sub-group analyses were performed between the cases with and without alignment change after rod fracture at S1/IL.Results: Of the 159 patients, the data of 110 patients (15 men, 95 women; mean age, 67.8 years) were analyzed. The follow-up rate was 69%. Forty-five (41%) patients showed DI (29 cases [26%] in screw loosening, 16 cases [15%] in rod breakage). Eight patients (7.3%) required revision surgery because of iliac screw-related complications. No significant differences were observed in the Oswestry Disability Index and Scoliosis Research Society questionnaire (revised) scores between the DI and non-DI groups. The patients with iliac screw loosening showed significantly greater values of preoperative pelvic incidence, pelvic tilt (PT) and postoperative PT, and T1-pelvic angle. In patients with rod breakage at S1/IL, five patients (31%) who had associated mechanical complications showed an alignment change between pre and post rod breakage. They showed significantly higher and lower rates of high-grade osteotomies and L5/S interbody fusion, respectively.Conclusion: The incidence rate of iliac screw-related complications was relatively high. However, they had a little effect on sagittal alignment deterioration and there were few cases that required revision surgery., Mini abstract:Long fusion surgery with pelvic fixation using iliac screw resulted in higher incidence rates of iliac screw-related complications; however, the cases that required revision surgery were limited (7.3%). Iliac screw loosening and rod breakage at S1/IL had little effect on sagittal alignment deterioration.

This clinical report with an 8-year follow-up describes the multidisciplinary management of a patient diagnosed with amelogenesis imperfecta. The rehabilitation included horizontal-guided bone regeneration, implant placement, use of a fixed interim prosthesis to preview the correction of occlusal disharmonies, and placement of a custom screw-retained definitive implant-supported restoration with a design that was retrievable and minimized maintenance problems.

Statement of problem. Polyetheretherketone (PEEK) has been advocated to replace metal components in dentistry. Although PEEK is a high-performance polymer with a white color, adequate biological response, and resistance to fracture, data to support PEEK as an alternative material for implant abutments are lacking. Purpose. The purpose of this in vitro study was to assess the mechanical and functional properties of PEEK implant abutments as a nonmetallic alternative to titanium abutments, which presents esthetic limitations and greater difficulty to customize clinically. Material and methods. Implant abutments manufactured by using PEEK (n=24) or titanium grade 5 (n=24) were attached to MIS Implants type M4 3.75×16 mm with an internal screw tightened to 25 Ncm. Screw loosening and microleakage was assessed by submersion in a 2% methylene blue solution for 48 hours at 37 C. Both groups were compared with and without applying dynamic loading; fatigue testing was performed following the International Organization for Standardization (ISO) 14801:2016 standard. All specimens were observed under a stereomicroscope at ×8 magnification. Statistically significant differences among the PEEK and titanium implant abutments were tested with 2-factor ANOVA and the chi-square analysis for nonpaired and paired data, respectively (a=.05). Results. The implant abutments made of titanium were better in all mechanical tests. The torque loss of titanium abutments was approximately 10%, while PEEK showed a significantly higher (P

Introduction Plating of unstable OTA/AO 44-B2 equivalent lateral malleolus (Danis-Weber B) fractures has been associated with pain, peroneal irritation, and the need for subsequent hardware removal (ROH). The purpose of this study is to retrospectively compare the rates of ROH in unstable Weber B fractures fixed with a posterior, true antiglide plate with no screws in the distal segment versus those that were fixed with a similarly placed posterior, neutralization construct that included screws in the distal fragment. Thus, evaluating the role of the distal screws in rates of ROH. Methods Skeletally mature patients that were treated for an unstable, isolated Weber B fracture at a single level-1 trauma center over a ten-year period were reviewed. Fractures treated with a single posterior plate with at least six months of follow-up were included and those fixed with a direct lateral plate were excluded. The primary outcome of this study was hardware removal defined as entire plate removal; isolated syndesmotic screw removal was not included. Results Ninety-six patients were included in the study with average age of 46 years (range 17-83) and mean length of follow-up of 24.5 months (range 6.1-140.3). There were 33 patients in the antiglide group (mean follow-up 25.5 months) and 63 in the neutralization plate group (mean follow-up 24 months, p=0.81). Fractures fixed with or without distal screws had equivalent excellent results related to bony union and alignment. However, there was a statistically significant decrease in ROH rates in the antiglide group (antiglide ROH rate 15.2%; neutralization ROH rate 38.1%; p=0.02). Relative risk of ROH with antiglide plate was 0.4 (95% CI 0.17 – 0.95; p=0.04). Conclusions Antiglide plating shows a significant risk reduction in the rate of ROH when compared to posterior based neutralization plating. A true antiglide plating construct should be considered as a safe and effective way of managing Weber B fractures with a lower relative risk of a second operation for hardware removal. Level of evidence Therapeutic level III. See Instructions for Authors for a complete description of levels of evidence.

Statement of problem Implant-supported and implant-retained extraoral prostheses are reliable treatment options for patients with craniofacial defects. They provide stable retention and therefore enhance the patient's appearance and quality of life. Despite studies on survival rates of extraoral implants, little attention has been paid to the design of the implants used to support and retain extraoral prostheses. Purpose The purpose of this longitudinal clinical study was to assess the long-term survival rate (1 to 12 years, mean 6 years) of 2 different designs of implants (disk: single, double, and triple and screw-type) used for extraoral epithesis anchorage. Material and methods Twenty-six participants with orbital and nasal defects, 10 of whom had had radiation treatment, were included in the study. Disk implants and extraoral (EO) screw implants were used and placed in the periorbital (15 participants) and perinasal regions (11 participants). Data were analyzed by using the Chi-square test and the Fisher Exact test for qualitative variables and the Mann-Whitney U test for comparison of quantitative variables. Implant survival rates were calculated by Kaplan-Meier analysis. Results The overall 12-year survival rate of all implants was 90.3% (mean=79 months), with 92.9% for nasal (mean=84 months) and 88.2% for orbital (mean=75 months) implants. Related to the implant design, survival rates were as follows: for single-disk implants, 90.2%; for double disks, 94.6%; for triple disks, 88.3%; and for screw implants, 83.3%. In nonradiated participants, the implant survival rate was 97.6%, and for radiated participants, 76.1%. Conclusions Survival rates for implant-retained craniofacial prostheses are limited. The nasal site seems to be a more predictable implant site than the orbital site, with a higher overall survival rate. Also, implants inserted in radiated tissues have lower survival rates for both anatomic sites, with statistically significantly lower results in the orbital region. The most reliable type of implant among the disk implants used was the double disk in the orbital site and the single disk in the nasal site, which may indicate the advantages of some designs in specific areas.

The purpose of this research was to compare insertion techniques and effects on mechanical and clinical parameters between 2 types of miniscrews.Forty-four consecutive patients whose orthodontic treatment involved the use of miniscrews (miniscrew A [MA] and miniscrew B [MB]) for anchorage were included in this study. Miniscrews were placed with predrilling or self-drilling; peak maximum insertion torque (MIT) and Periotest values were measured. Cone-beam computed tomography was performed after the insertion of miniscrews and root proximity determination; cortical bone thickness was also analyzed. Periotest values were measured after the application of orthodontic force.Self-drilling produced higher Periotest values (P 0.01) for MA and higher MIT (P 0.01) for MB with closer root proximity (P 0.05). MB had higher MIT and Periotest values with drilling compared with MA (P 0.05); MB also showed closer root proximity (P 0.05). Successful miniscrews had lower MIT (P 0.05) for MB and lower Periotest values (P 0.01) for both MA and MB, with significantly more distant root proximity (P 0.01). Self-drilling produced higher Periotest values at the time of placement (P 0.01) and after 4 weeks (P 0.05) in MA. Drilling produced higher Periotest values for MB at the time of placement (P 0.05). MIT had positive correlations with Periotest values for MB with self-drilling (P 0.01) and with root proximity for MA with drilling (P 0.01). Periotest values had negative correlations with root proximity for MA and the MB group with drilling (P 0.01).For miniscrews with larger diameters, higher MIT may result in more mobility (higher Periotest values). Drilling can avoid root contact and enhance primary stability, thus producing lower Periotest values.

Background: The purpose of this study was to investigate variations in radiographic metacarpal anatomy as it relates to intramedullary (IM) fixation of metacarpal fractures and to compare this anatomy with available headless screw dimensions. Methods: We radiographically analyzed posteroanterior and lateral (LAT) radiographs of 120 metacarpals across 30 patients without structural abnormalities. Primary outcomes included IM isthmus diameter, isthmus location, metacarpal cascade, and head entry point collinear with IM canal. Measurements were compared with a list of commercially available headless screws used for IM fixation. Results: The average largest isthmus diameter was in the small metacarpal (3.4 mm), followed by the index (2.8 mm), long (2.7 mm), and ring (2.7 mm) metacarpals. The average cascade angle between long and index, long and ring, and long and small metacarpals was 0°, 24°, and 27°, respectively. The appropriate head entry point ranged between 25% and 35% from the dorsal surface of the metacarpal head on a LAT view. The retrograde isthmus location of the index and long finger was 39.2 and 38.1 mm, respectively. Twenty-five screws from 7 manufacturers were analyzed with sizes ranging from 1.7 to 4.5 mm. Only 8 of 17 screws between 2.3 and 3.5 mm had a length range above 35 mm. Conclusions: Metacarpal head entry point and cascade angle can help identify the appropriate reduction with the guide pin starting point in the dorsal 25% to 35% of the metacarpal head. Surgeons should be mindful to choose the appropriate fixation system in light of the variations between metacarpal isthmus size, isthmus location, and available screw lengths.

Pressure therapy is widely used in the management of keloid mass and for preventing postexcision recurrence of earlobe keloid. Although various types of compression devices are available, the pressure applied by these devices is uncontrolled and associated with the risk of pressure necrosis. This article presents a novel design for a compression device with threaded connectors to control the amount and direction of the pressure applied on the keloid mass.

A complete digital workflow to remove a cement-retained implant-supported crown by using an additively manufactured implant abutment screw-access guide is described. The existing cone beam computed tomography (CBCT) scan was superimposed on the digital scans of the patient, which facilitated the visualization of the implant abutment screw access and guided the design of the device. Advantages of the technique described include the precise translation of the implant abutment screw access, safe removal of the implant crown, and conservative clinical intervention.

Although leg length discrepancy (LLD) commonly occurs following in situ fixation with screws for slipped capital femoral epiphysis (SCFE), the literature regarding this issue is scarce. The purpose of this study was to evaluate the degree of LLD in patients who had been treated with in situ fixation with screws and to identify the risk factors for the development of LLD. We retrospectively reviewed 44 patients (mild slip 24, moderate slip, 20) who were treated with in situ fixation with screws for SCFE. The mean age at surgery was 12.2 years and the mean follow-up period was 6.9 years. We investigated the relationship between the final LLD, articulotrochanteric distance difference (ATDD) at skeletal maturity, and various clinical and radiographic parameters using linear regression analysis. The mean values of LLD and ATDD were 13.1 and 11.1 mm, respectively. The LLD and ATDD was significantly higher in patients with moderate slips than in those with mild slips. The degree of slip angle was associated with the degree of LLD only. While there was no significant factor affecting the LLD in moderate slips, younger age and a larger degree of slip angle were associated with the degree of LLD. The degree of slip was the only factor that affected LLD in patients with mild or moderate SCFE who underwent threaded screw fixation. Age at surgery was not associated with LLD, and there were no factors related to the degree of LLD in mild slip. Monitoring for LLD may only be necessary for patients with moderate slip who are treated with in situ screw fixation.

Introduction: Patellar fractures constitute almost 1% of total skeletal injuries. Existing common operative methods include the use of different types of Tension band wiring techniques like cannulated screws and K-wires. The Patellar plating construct is a relatively newer operative method for patellar fracture fixation with promising outcomes with fewer complications. Method: We conducted a pilot prospective study at our Apex Trauma Centre in twenty patients aged 18- 65years with displaced patellar fractures, AO type A2, A3, B2, B3, C1, C2, C3. Fractures were fixed with low profile patellar plates (1.8mm). Radiological and functional follow-up was done using X-rays, CT scans and BKS scoring (Bostman-Knee-Scale), Knee Society Score(KSS), and Tegner Lysholm knee scores respectively for two years. Result: Mean functional outcome scores at 6 weeks, 3 months, 6 months and 2 years was 25.5, 28.3, 29.05 and 29.9 for BKS; 64.62, 84.12, 90.6, and 97.5 for KSS; 73.75, 89.7,94.8, and 99.3 for Tegner Lysholm knee score respectively. Radiological union, confirmed by CT scan, was observed in all patients at 3 months. Two patients had superficial surgical site infection (SSI) at 2 weeks. Implant impingement was also found in 2 patients at 3 months. None of the patients had a failure of fixation at the end of the study. Conclusion: Patients with low profile patellar plate constructs have favorable clinical and radiological outcomes with minimal non-specific complications.

We evaluated the effects of using a navigation technique with anterior approach surgery for thoracolumbar burst fractures on vertebral body screw placement and discussed its effects on the long-term prognosis of patients.We performed a prospective study of patients who had undergone anterior approach thoracolumbar surgery from May 2018 to August 2019. The 40 patients were randomly divided into the navigation group (NG) and control group (CG). In the NG, vertebral body screw placement was performed with 2-dimensional navigation guidance. For the CG, no navigation guidance was used. The clinical and radiological evaluations of the 2 groups were compared preoperatively, immediately after surgery, and at the final follow-up. Paired t tests and the χNo differences were found in the hospital stay, operation time, autologous blood recovery, postoperative drainage volume, Cobb angle of the preoperative coronal plane and sagittal plane, postoperative sagittal plane, postoperative Cobb angle of the coronal and sagittal planes measured on radiographs and computed tomography scans between the 2 groups (P0.05). The correction of the kyphosis deformity of the fracture segment was better in both groups (P0.001). The intraoperative blood loss and Cobb angle of the postoperative coronal plane in the NG was less than that in the CG (P0.05). Also, the 4 vertebral body screws in the NG were more parallel to the endplate than were those in the CG.We found that the use of navigation can improve the accuracy of screw placement in anterior approach surgery for thoracolumbar burst fractures and improve patients' long-term prognosis.

The choices of the treatments for femoral neck fractures (FNF) remain controversial. The purpose of this study is to evaluate the prognoses of the variable pitch fully threaded headless cannulated screws (HCS) in the fixation of femoral neck fractures and to compare them with those of partially threaded cannulated screws (PCS). Between 1st January 2012 and 31st December 2016, there were 89 patients with the main diagnose of FNF who accepted the treatment of closed reduction cannulated screw fixation in Peking University People’s Hospital. 34 cases of PCS and 23 cases of HCS met the criterion. The characteristics, prognoses and the imaging changes of all cases were described and the differences between the two groups were compared. Statistical analyses were performed using SPSS version 23.0 (SPSS Inc., USA). Mann–Whitney U test, Analysis of Variance and Chi-square test were used. Statistical significance was defined as P value (two sided) less than 0.05. There was no significant difference in the general characteristics, fracture classifications and reduction quality between the two groups. HCS group had a significant lower angle decrease rate (30.4% vs. 58.8%, P = 0.035), femoral neck shortening rate (26.1% vs. 52.9%, P = 0.044) and screw back-sliding rate (21.7% vs. 50.0%, P = 0.032), but a higher screw cut-out rate (21.7% vs. 0.0%, P = 0.008). In non-displacement fracture subgroup, HCS had significant higher Harris Score (92 vs. 90, P = 0.048). Compared with PCS, HCS had a lower screw back-sliding rate, femoral shortening rate, angle decrease rate and similar function score, but would result in more screw cut-outs in displaced FNF. As a conclusion, HCS should not be used in displaced FNF due to its higher screw cut-out rate, and its potential advantage in non-displaced FNF needs to be further proved. Further qualified investigations with a larger scale of patients and longer follow-up are needed in the future.

Introduction Femoral neck fractures in the young patient present a unique challenge. Most surgeons managing these injuries prefer a fixed angle implant, however these devices are fraught with problems. A dynamic hip screw (DHS) is one such fixed angle device that risks malreduction through rotational torque during screw insertion. To avoid this risk some surgeons utilize a dynamic helical hip system (DHHS), however little is known about the complication profile of this device. We hypothesized that the complication rate between these two devices would be similar. Patients and Methods All patients presenting to a single tertiary referral center with a femoral neck fracture were identified from a prospectively collected trauma database over an 11-year period. Patients were included if they were less than 60 years of age, treated with a DHS or DHHS, and had at least 6 months of follow-up. Demographic data, injury characteristics, and post-operative complications were obtained through chart review. Standard statistical comparisons were made between groups. A total of 77 patients met inclusion criteria. Results Average age of patients was 38 years (range: 18–59) and 56 (73%) were male. The DHS was used in 37 (48%) patients and the DHHS was used in 40 (52%) patients. Demographic data including average age, gender, body mass index, and smoking status did not differ between the groups. There were 29 (39%) total complications of interest (femoral neck shortening >5 mm, non-union requiring osteotomy, conversion to THA, and osteonecrosis. There were 19 (51%) complications in the DHS group and 10 (25%) in the DHHS group (p = 0.01, risk difference 25%, 95% CI 7–43). Comparisons of the individual complications about the DHS and DHHS cohort did not reach statistical significance for non-union (8% vs 3%) or THA (16% vs 13%) (p = 0.33, p = 0.64, respectively) but a difference was detected in the rate of shortening (27% vs 10%; p = 0.05). Conclusion This study demonstrates a high risk of complication when managing young femoral neck fractures in line with prior literature. The major complication rate of non-union requiring osteotomy or fixation failure resulting in THA was no different between the two groups, but the rate of shortening was greater the DHS group. This data suggests the DHHS may be a suitable device to manage the young femoral neck fracture and without increased risk of complication.