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Background A lack of scientific information regarding the risk factors and diagnosis of peri-implant atypical femoral fracture (PI-AFF) exists. We report a case series of developed PI-AFF with a nail or plate construct wherein prior femoral fractures were already healed after osteosynthesis. This study aimed to identify the cause and risk factors of PI-AFF and to devise a preventive method based on this. Methods We identified 11 PI-AFFs displaying features of AFFs. All patients were ambulant females (mean age, 74.9 years). The mean T-score of the femur measured by DEXA (Dual Energy X-ray Absorptiometry) scan was 3.5. Osteosynthesis was performed with a plate and an intramedullary nail in six and five patients, respectively. Possible risk factors were investigated, including the used implant, the medication of bisphosphonate, the characteristics of previous fracture (AFF or non-AFF), and the co-existence of AFF on the contralateral side. Results The PI-AFFs developed at an average of 6.6 years from the time of prior fracture. All fractures were located at the screw through the plate or nail. Regarding anatomic locations, seven and four fractures were at the subtrochanteric area and diaphysis, respectively. Diaphyseal PI-AFFs occurred in plating cases, all of which were associated with excessive femoral bowing. Subtrochanteric PI-AFFs included all five patients with nail fixation, which occurred near a proximal interlocking screw. Six of the 11 patients were on bisphosphonate treatment before or at the time of fracture. The duration of bisphosphonate treatment was 6 years on average. Concerning the previous femoral fractures, seven and four patients were AFF and non-AFF, respectively. Considering the pathology on the contralateral leg, eight had suffered diaphyseal AFF. Four patients were treated nonoperatively. Seven patients needed an operation; 6 of them healed after reconstruction nailing, and one needed hip arthroplasty because of the associated displaced femoral neck fracture. Conclusions PI-AFFs may develop through the screw hole at the subtrochanteric or diaphyseal area due to femoral fragility and stress riser effect of the implant. An improved osteosynthesis strategy may be necessary to avoid PI-AFFs when fixing osteoporotic femoral fractures.

Background In shoulder arthroplasty, bone resorption around the stem can lead to stem loosening and makes surgery difficult at the time of revision. Proximal bone resorption after reverse shoulder arthroplasty can cause instability because of a decrease of deltoid wrapping effect. As factors of the stem itself, such as stem coating, shape, length, and use of bone cement, may also affect bone resorption, a single-stem model should be used to compare bone resorptions between different pathologies and surgical procedures. However, to date, a few reports have compared these differences in detail using a single-stem model. Therefore, we investigated the prevalence and location of humeral bone resorption in a single-stem model. Methods The study included 100 shoulders that underwent anatomical total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with a single uncemented humeral stem from 2008 to 2018. The patients were 31 men and 69 women. The mean age at surgery was 72.9 years (range, 41-86 years). The patients were divided into three groups: especially, 25, 61, and 14 shoulders received TSA for primary osteoarthritis without rotator cuff tears (TSA group), HHR using an anatomical head with rotator cuff repair for cuff tear arthropathy (CTA) (HHR group), and HHR using a CTA head without rotator cuff repair (CTA group), respectively. Patients were monitored for a mean of 56 months (range, 12-98 months). The location of bone resorption was divided into seven zones as follows: zone 1, greater tuberosity; zone 2, lateral diaphysis; zone 3, lateral diaphysis beyond the deltoid tuberosity; zone 4, tip of the stem; zone 5, medial diaphysis beyond the deltoid tuberosity; zone 6, medial diaphysis; and zone 7, calcar region. The degree of bone resorption was classified from grade 0 to 4. Results Bone resorption of grade 3 or higher was significantly more frequent at the greater tuberosity in the HHR and CTA groups (P Conclusion The state of attachment of the rotator cuff to the greater tuberosity might affect bone resorption at the greater tuberosity, such as the greater tuberosity after shoulder arthroplasty. In cases of shoulder arthroplasty for arthropathy with rotator cuff tear, performing rotator cuff repair might prevent bone resorption. Level of evidence Level IV; Prognosis Study

Background Previous studies have evaluated the initial stability of uncemented tibial components in revision total knee replacement (rTKR) in the presence of an Anderson Orthopaedic Research Institute (AORI) Type II tibial defect. This study sought to evaluate similar metrics in the severe Type III (AORI TIII) defects with combined uncemented stem and sleeve fixation, specifically, the effect of varying the stem’s length and tibial canal engagement upon stability and bone strain. Method Finite element models generated from the CT scans of 4 tibias with Type III defects were used to investigate the primary stability, in terms of the bone–implant composite peak micromotion (CPM) and microstrains (CPS), achieved after virtual implantations with and without stems. Results A stemless rTKR had increased metaphyseal CPM and CPS compared to all stemmed implants. Significant area of the bone supporting the stemless rTKR had CPS greater than bone yield (7000 μe). Short engaging stems (≤150 mm construct length), could not achieve reliable engagement in the diaphysis (canal fill ≤ 50%), leading to insufficient reduction of CPS (≥5000 μe). Longer engaging stems (170–220 mm construct length), were able to reliably engage the diaphysis (fill ratio ≥ 75%) resulting in CPS ≤ 5000 μe. Although, non-engaging stems resulted in increased CPM and CPS compared to engaging stems, long non-engaging stems (170–220 mm construct) appeared to provide additional stability to the rTKR compared to stemless rTKR. Conclusion The results indicate a likely correlation between uncemented stem engagement and metaphyseal CPS in Type III defects. Excessive strain within the supporting metaphyseal bone is likely to lead to rTKR migration and loosening.

Introduction Internally cooled bone drills with an open system, conduct coolant directly to the point of contact of cutting surface of the drill and the bone and lower the temperature at the drilling site. During bone drilling with internally cooled drills of open type, there is a possibility that coolant enters the intramedullary canal and has an adverse effect on intramedullary pressure. In this research, the intramedullary distribution of the coolant during and after drilling was analyzed. Materials and Methods Specially constructed open type internally cooled medical steel drills were used. Experimental studies were conducted on the porcine femoral bone diaphysis. Coolant (saline) was mixed with water-soluble contrast agent and x-ray images of the distribution of coolant during and after drilling were taken with different regimes of drilling (drill rotational speed from 1300 rpm to 5000 rpm, and coolant flow rate from 0,6 l/min to 1,35 l/min). Results An x-ray images showed that coolant did not spread from the borehole and has not spread intramedullary with any combination of coolant flow and drill rotation regimes. Conclusion Coolant does not disperse into the intramedullary canal outside of the borehole in given flow ranges (0,6–1,35 l/min) and drill rotational speed regimes (1300–5000 rpm). Open type internally cooled can safely be used for bone drilling.

Since the cross-sectional geometries of long bone diaphyses preserve evidence of a bone's mechanical loading history, examination of a bones' cross-sectional properties can be used to inform its loading history. Here, we use a novel colormap method to quantitatively visualize the topography of cortical bone, second moment of areas, and polar moment of areas along the humeral diaphyses to shed light on the potential manipulative behaviors of the Tianyuan 1 fossil human (Homo sapiens). We compare both humeri of Tianyuan 1 to two Holocene Chinese populations. Our results show that the standardized cortical bone thickness, standardized second moment of areas, and standardized polar moment of areas of Tianyuan 1's right humeral diaphysis are greater than those of the left diaphysis. This evidence supports the hypothesis that the individual was right-handed. The greater medial and lateral cortical reinforcement in the right midshaft humerus, relative to that of the left humerus, may be related to increased unilateral physical activity of the right arm. Unlike the lower humeral asymmetry of recent human agriculturalists, the relatively higher bilateral asymmetry, combined with the relatively larger femoral robusticity, indicate that Tianyuan 1 lived an activity lifestyle compared to the agriculturalists investigated in this study. The bilateral asymmetry of the right and left humeri may be more informative for discriminating between fossil and recent modern human samples than cortical thickness or rigidity values in only one side. This study also indicates that upper limb internal structures can provide important information for inferring the behavior of ancient hominins.

Introduction Aneurysmal bone cysts (ABCs) are benign lesions of long bone metaphysis affecting mostly medullary region in younger age below 20 years of life. These may be originated rarely either in the cortex or in the superficial regions of diaphysis. The study highlighted the differences of diaphyseal lesions from the usual metaphyseal ones in view of their clinical, radiological and biological behavior and also discussed their management in brief. Material and methods We reviewed a total of 84 aneurysmal bone cysts over the past fourteen years (2004–2017) and evaluated their surgical outcomes retrospectively. Total ten lesions were diaphyseal cortical in location (group I), while 74 lesions were conventional metaphyseal type (group II). Results We observed that cortical ABCs were occurred commonly in diaphysis of femur, humerus, tibia and radius while presentation was at an older age than metaphyseal type. Radiographically these were eccentric lesion and more prone for pathological fractures than conventional type. These are differentiated radiographically from other benign lesions but also mimicking malignant conditions including low grade surface osteosarcoma and telangiectatic osteosarcoma while resemble similar to these on histopathological examination (HPE). Conclusion Biological behavior of cortical lesions does not differ significantly than conventional type but these are more prone for pathological fractures so these eccentric cortical ABC lesions should be treated with adequate internal fixation along with curettage and bone grafting. Although incidence of cortical or surface variety of ABCs is rare but surgeons might evaluate its severity in view of aggressive benign or malignant lesions of diaphysis.

Background The purpose of this study was to evaluate the relative contribution of the reverse shoulder arthroplasty (RSA) humeral stem length on initial implant fixation, which may contribute to the long-term success of uncemented shoulder implants. Methods Three RSA humeral components were randomly divided into the following testing groups: (1) 100% Stem length (n = 7); (2) 50% Stem length (n = 7); (3) 0% Stem length (n = 7). Each humeral stem was press-fit into twenty-one 4th Generation Osteoporotic Sawbones humeri. Torque and compressive axial load were applied to the humerus for 10,000 cycles at ±2.5 Nm and −392 N, respectively. Rotational micromotion of the implant was measured. Results Micromotion for all 3 testing groups was below the 150 µm micromotion threshold throughout testing. The overall micromotion in Group 2 was significantly larger than Group 1 (P Conclusion All stem lengths studied maintained micromotion below the 150 µm threshold, suggesting that any of these treatment groups would provide adequate initial fixation to allow bony on-growth. Clinically, stemless or short-stemmed prosthesis design offer theoretical benefits such as the degree of freedom for humeral stem placement independent of diaphysis. This study concluded that the zero-length stem will allow for this and provide adequate fixation comparable to the full-length stem. Level of Evidence Basic Science Study.

While Ewing sarcoma of bone is the second most common primary osseous malignancy in childhood where it typically involves the diaphysis or metadiaphyses of long bones of skeletally immature patients, primary epiphyseal involvement of the long bone in skeletally mature patients is rare with no cases reported in the literature to our knowledge, rendering this case the first of its kind. We present the first case of primary Ewing Sarcoma of the epiphyses of the long bones in a skeletally mature 20-year-old male patient. The patient initially presented with left knee stiffness and pain that was empirically treated with non-steroidal anti-inflammatory medications. His pain progressed despite treatment. An x-ray of the left knee was obtained 5 months later demonstrating an irregular lucent lesion in the medial femoral condyle. A subsequent MRI revealed an enhancing lesion in the medial femoral condyle, and when biopsied it was consistent with Ewing sarcoma (positive for EWSR1gene rearrangement by fluorescence in situ hybridization). The lesion was resected surgically, and the patient underwent neoadjuvant chemotherapy with a good clinical outcome.

Purpose To compare the likelihood of spiral fracture of the humerus using torsional load to failure after intraosseous biceps tenodesis at the position of the arthroscopic suprapectoral tenodesis versus the subpectoral meta-diaphyseal location. Methods Eight matched pairs of humeri were dissected. Unicortical tenodesis holes were drilled, either at the bottom of the bicipital groove (group 1) or just below the pectoralis major tendon insertion (subpectoral) in the humeral diaphysis (group 2). Tenodesis was performed in a 7-mm bone tunnel, with suture fixation distal to this site using 2 separate 2-mm holes, secured with No. 2 polyester suture. Each humerus was potted in plaster and mounted to a hydraulic torsional load frame, consistent with previously validated models for creating humeral spiral fractures. External rotation torque was applied to each humerus distally until fracture occurred. The paired t test was used to compare the 2 groups. Results Fracture occurred at the subpectoral cortical drill hole in all 8 specimens in group 2. In group 1, only 2 fractures occurred through the tenodesis hole, with spiral fracture resulting in the diaphysis of the humerus in 6 of 8 specimens. Average torque to failure measured 31.35 Nm in group 1 and 25.08 Nm in group 2; the difference was statistically significant (P Conclusions Subpectoral cortical drill holes for biceps tenodesis were shown to be a stress riser for humeral spiral fracture. Suprapectoral cortical drill holes were shown to be significantly less of a stress riser. The amount of torque required to fracture the humerus through the subpectoral drill holes was less than with the suprapectoral drill holes. Only 2 fractures occurred through the suprapectoral tenodesis holes, and significantly more torque was required to create these fractures. Clinical Relevance Clinically, the difference between suprapectoral and subpectoral tenodesis fracture potential should be considered when selecting a tenodesis location.

Reduction in cortical bone mineral density at diaphysis of metacarpal bones of the hand, evaluated by dual X-ray radiogrammetry, has a bad prognostic value in patients with early arthritis. Nevertheless, this technique is hardly accessible in clinical practice. By contrast, evaluation of cortical bone mineral density at that location has not been previously assessed by conventional dual X-ray absorptiometry. The aim of this study is to evaluate the reproducibility of bone mineral density measurements at diaphysis of metacarpal bones using conventional dual X-ray densitometry in a population of healthy volunteers and patients with early arthritis. Nondominant hand dual X-ray densitometry was performed at three consecutive times with complete hand replacement in 27 subjects: 10 early arthritis and 17 healthy volunteers. Three different evaluators analyzed the 3 measurements of second to fourth metacarpal bones. To assess the reproducibility and accuracy of the measurements, intra- and interobserver agreement degrees, intra- and interclass correlation coefficients, smallest difference detectable assessment, and Bland Altman graphs were calculated. The coefficients of variation obtained for the different metacarpal evaluations were 2.25%, 2.91%, 2.85%, and 2.07% for metacarpal-2, metacarpal-3, metacarpal-4, and mean metacarpal-second to fourth, respectively, with a smallest difference detectable of 0.028, 0.034, 0.028, and 0.03 g/cm2, respectively. The mean intra- and interobserver correlation coefficients between of metacarpal second to fourth were 0.990 (95% confidence interval [CI]: 0.982–0.995) and 0.995 (95% CI: 0.991–0.997), respectively. As expected, women had lower bone mineral density at metacarpal bones, especially after menopause. The results obtained in this study show an excellent reproducibility of bone mineral density measurements at diaphysis of metacarpal bones of the hand, measured by conventional dual X-ray densitometry, in a mixed population of healthy subjects and patients with early arthritis. This is of great interest for longitudinal studies in patients with early arthritis.

Introduction Multiple hereditary exostosis (MHE) is the formation of benign, cartilage-capped bony outgrowths predominantly extending from the metaphysis of long bones that presents with reduction in growth, deformity, restricted motion, short stature and premature osteoarthritis. Aim To review the clinical and radiological results of a stemless reverse shoulder arthroplasty in a case of MHE. Case 81-year-old, right hand dominant short-statured retired male engineer with long standing shoulder pain and restricted movements on the background of an old proximal humeral fracture managed conservatively. The radiographs revealed osteoarthritis and a mal-united proximal humerus fracture on the background of MHE with 3 plane bone deformity and a lack of medullary canal. Results The patient underwent a stemless reverse shoulder arthroplasty. At 6 months post operatively the patient had recovered well with a range of movement including: forward flexion 110°, external rotation 20° and abduction of 80°. Internal rotation remained limited to buttocks. Improved ADLIER, Subjective shoulder value and Constant Murley score compared to pre-operative figures. Conclusion The stemless humeral component relies on metaphyseal impaction for stability. When the humeral canal is malformed or in presence of malunited distal fractures, it circumvents the need of navigating a deformed diaphysis with encouraging postoperative results.

Introduction Short stem humeral stem components represent an area of potential advancement that may decrease the risk of complications associated with traditional length stems, but early data has demonstrated a high rate of malalignment with certain designs. The utilization of a short stem specifically designed to self-align in the proximal portion of the diaphysis has the potential to provide more consistent adequate alignment. Methods A multicenter retrospective review was performed on 269 shoulders that had undergone an anatomic Total shoulder arthroplasty or a reverse shoulder arthroplasty with implantation of a self-aligning short stem humeral component. Radiographic outcomes included stem alignment and fill-fit ratios. Results Radiographs showed adequate stem alignment in 94% of the shoulders. The differences in the superior region canal-fill ratio between the neutral and malaligned group were statistically significant (P Conclusion The self-aligning short stem analyzed in this study provided a very high rate of adequate stem radiographic alignment. Higher fill ratios were correlated with improved stem alignment. Further studies are needed to understand if improved initial alignment rates correlate with improved patient outcomes or a decreased rate of mechanical failure or other complications. Level of evidence IV

Background Percutaneous osseointegrated (OI) docking of prosthetic limbs returns loading directly to the residual bone of individuals with amputations. Lower limb diaphyseal biomechanics have not been studied during the wide range of daily activities performed by individuals with lower extremity amputations; therefore, little is known about the loads experienced at the bone-endoprosthetic interface of a percutaneous OI device. Research question Does residual limb length and/or gender influence loading magnitudes in the diaphysis of the femur or tibia during daily activities? Methods This observational study used motion capture data from 40 non-amputee volunteers performing nine activities ranging from low to high demand, to virtually simulate residual limbs of amputees. To simulate diaphyseal bone loading in individuals with lower limb amputations, virtual joints were defined during post-processing at 25, 50, and 75 % of residual limb length of both the femur and the tibia, representing six clinically relevant residual limb lengths for OI device placement. Peak axial distractive and compressive forces, torsional moments, and bending moments were calculated for each activity. Comparisons were made between genders and between different levels of the simulated residual limb. Results For simulated above and below knee amputations, short residual limbs showed the highest average bending, torsion, and axial distractive loads, while axial compressive loads were highest for long residual limbs. Absolute maxima for all subjects showed this same trend, except in below knee torsion, where 75 % residual tibia length showed the maximum. The highest demand activities yielding peaks in all directions were cutting with right leg planted, jump, run, and fall. Significance Overall, individuals with shorter residual limbs experienced higher diaphyseal forces. This should be taken into consideration during surgical implantation of percutaneous OI devices where residual limb length can potentially be shortened, and during rehabilitation of percutaneous OI patients.

Intraosseous ganglion is a benign cystic lesion located in the subchondral region and in the epiphyseal areas of long and short tubular bones. It occasionally extends to the metaphysis and diaphysis regions and rarely involves the metatarsal bone. In this report, a case of intraosseous ganglion of the second metatarsal extending from metaphysis to diaphysis was presented. This presented with dull aching pain of the forefoot dorsum, and the diagnosis was confirmed by magnetic resonance imaging. It was successfully treated by endoscopic curettage and bone grafting without the need of lengthy incision of open surgery. The patient remained asymptomatic and had no evidence of local recurrence 28 months after the surgery. This report demonstrated the feasibility of endoscopic surgery in treatment of extensive intraosseous benign lesion of the metatarsal bone.

Atypical femoral fracture (AFF) associated with bisphosphonate (BP) use is common, and its pathophysiology is considered to involve severely suppressed bone turnover. Surgical results following AFF fixation have not been optimal, with some cases resulting in delayed union or nonunion. Regarding bone healing, glucocorticoid (GC) has similar properties to BP. We investigated the surgical results of AFF fixation in both users of BP and GC, especially with regard to intraoperative fracture reduction. We included 12 AFFs in 11 patients with a follow-up over one year who all took GC for autoimmune disease and BP for management of GC-induced osteoporosis. Their mean age was 62 years and 10 patients were female. Six fractures were located in the subtrochanteric region of the femur and six were in the diaphysis. Intramedullary nails were used to treat all fractures. Union rate was recorded, and the status of the reduction immediately after the operation was analyzed. Four of the 12 cases developed nonunion, and three of them required additional surgery. The relationship between alignment, cortical continuity, fracture gap, and bone union was not significant. In the nonunion cases, cortical continuity on the anteroposterior and lateral views were never confirmed. Even if cortical continuity in either of the views was there, the two limbs resulted in nonunion. One third of the patients with AFF secondary to long-term BP and GC use developed nonunion despite their fracture reductions being acceptable. We consider strict reduction should be needed for these cases with disadvantage condition to bone union.

Highlights • Brodie’s abscess occurring in upper extremities is rare. • Penumbra sign identified on MRI is a useful finding for diagnosis. • We recommend that bone grafting after curettage of the abscess cavity is not always necessary for upper extremities., Introduction Brodie’s abscess is an uncommon type subacute osteomyelitis. It is typically localized in the metaphysis of tubular bones, particularly in the lower extremities. We herein report a rare case of the abscess appearing in the upper extremities. Furthermore, we successfully treated the large abscess without autogenous bone grafting. Presentation of case 14-year-old female presented with pain and swelling on the right forearm. Plain radiograph and CT scan indicated a 10 cm longitudinal cortical bone hypertrophy and a well-defined radiolucent lesion in the diaphysis of the right radius. MRI demonstrated that the lesion was hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging inside as well as outside the bone marrow of the radius. Laboratory data showed no inflammatory response, but Staphylococcus aureus was detected by biopsy. We diagnosed Brodie’s abscess of the radius, and performed definitive surgery. Infected bone marrow was curetted and a bony sequestrum inside the cortical bone was harvested. We did not use autogenous bone grafting, since the upper extremities are areas of unloaded bone. Postoperative administration of antibiotics was subsequently performed. One year after surgery, the patient was asymptomatic and there were no complications or signs of infection recurrence. Conclusion We diagnosed and surgically treated a rare case of Brodie’s abscess of the radius in an adolescent. An abscess with large cavity is usually treated by curettage and autogenous cancellous bone grafting. However, since the upper extremities are areas of unloaded bone, we successfully treated the abscess by debridement without bone grafting.

Purpose Atypical ulnar fracture (AUF) related to prolonged bisphosphonate therapy is a rare complication. We propose diagnostic criteria of AUFs and present a treatment algorithm. Methods Twelve AUFs in 10 patients were studied. The diagnosis of AUF was based on the case definition of atypical femoral fracture (AFF). We investigated clinical and radiographic characteristics of AUFs according to major and minor features of AFFs, and modified the case definition of an AFF to fit the characteristics of AUFs. All AUFs were treated surgically. The radiographic union of fractures was investigated, and delayed fracture healing was defined as a delay of 6 months or more. Results The average point at which AUFs occurred was at a point 35.1% along the proximal diaphysis of the total ulnar length. All major features of AFFs were identified in the 12 AUFs. Among the minor features, generalized cortical thickening was observed in 6 AUFs, prodromal symptoms in 2 AUFs, bilateral involvement in 2 patients, and delayed fracture healing in 10 AUFs (5 delayed union, 5 nonunion). Initially, 11 of 12 AUFs were treated with plating, and 1 was treated with intramedullary nailing . Two nonunions were revised with sclerotic bone resections , bone grafts , and plate fixation . Finally, union was achieved in 9 AUFs. Conclusions The case definition of AFFs can be used for the diagnosis of AUFs, although some modifications must be included in the case definition. Plating is useful in managing AUFs, although sclerotic bone resections and bone grafts may be required. Atypical ulnar fractures occurred in patients who took bisphosphonates longer than AFFs or those whose bisphosphonates were discontinued a few years earlier. Therefore, physicians should be aware of AUFs in those patients and, if necessary, perform a screening test to look for atypical fractures in other bones. Type of study/level of evidence Diagnostic V.

Background Various options exist for implant fixation in revision total knee arthroplasty. One of it is direct cementless metaphyseal sleeve fixation with stems, which has shown excellent short-term and midterm results. Stemless fixation of sleeves is another fixation option for the treatment of specific bone defects; however, so far no data in larger series exist. The objective of this study was, therefore, to analyze the midterm (3-6.5 years) results of stemless sleeve fixation in a larger revision total knee arthroplasty series. Methods In this prospective study, 85 patients with 109 stemless sleeves have been assessed with a mean follow-up of 58.2 (36-78) months. An exclusion criterion was uncontained type II and type III defects. Analysis included clinical and radiographic assessment. Results The results showed a survival rate of sleeves in 96% of the tibia (27/28) and 100% of the femur (81/81). This results in an overall survival rate of sleeves of 99% (108/109). So far, 10 patients (11.8%) underwent rerevision during the follow-up period. The main reason for failure was infection (4/85; 4.7%). Range of motion, Oxford Knee Score, Knee Society Score, and Functional Score improved significantly. Mechanical leg alignment was within the 3° corridor in all patients. Conclusions In cases with type I and contained type II defects, sleeves without stems are a promising option, with a survival rate of sleeves of 99% after 5 years. Also, the clinical improvement and reconstruction of leg alignment showed excellent results. In uncontained defects and type III defects, however, we do recommend using stems for additional fixation in the diaphysis. Although the midterm results are very promising, long-term data are needed.

The abundant femoral assemblage of Homo naledi found in the Dinaledi Chamber provides a unique opportunity to test hypotheses regarding the taxonomy, locomotion, and loading patterns of this species. Here we describe neck and shaft cross-sectional structure of all the femoral fossils recovered in the Dinaledi Chamber and compare them to a broad sample of fossil hominins, recent humans, and extant apes. Cross-sectional geometric (CSG) properties from the femoral neck (base of neck and midneck) and diaphysis (subtrochanteric region and midshaft) were obtained through CT scans for H. naledi and through CT scans or from the literature for the comparative sample. The comparison of CSG properties of H. naledi and the comparative samples shows that H. naledi femoral neck is quite derived with low superoinferior cortical thickness ratio and high relative cortical area. The neck appears superoinferiorly elongated because of two bony pilasters on its superior surface. Homo naledi femoral shaft shows a relatively thick cortex compared to the other hominins. The subtrochanteric region of the diaphysis is mediolaterally elongated resembling early hominins while the midshaft is anteroposteriorly elongated, indicating high mobility levels. In term of diaphyseal robusticity, the H. naledi femur is more gracile that other hominins and most apes. Homo naledi shows a unique combination of characteristics in its femur that undoubtedly indicate a species committed to terrestrial bipedalism but with a unique loading pattern of the femur possibly consequence of the unique postcranial anatomy of the species.

Stress fractures are common overuse injuries caused by repetitive bone loading. These fractures are of particular concern for military recruits and athletes resulting in attrition in up to 60% of recruits that sustain a fracture. Army and Navy recruits supplemented with daily calcium and vitamin D (Ca + D) demonstrated improved bone strength and reduced stress fractures. The aim of the current study was to evaluate whether Ca + D supplementation improves measures of bone health in recruits undergoing United States Marine Corps initial military training (IMT), and whether the effect of supplementation on indices of bone health varied by season. One-hundred ninety-seven Marine recruits (n = 107 males, n = 90 females, mean age = 18.9 ± 1.6 y) were randomized to receive either Ca + D fortified snack bars (2000 mg Ca and 1000 IU vitamin D per day) or placebo divided into twice daily doses during 12 weeks of IMT. Anthropometrics, fasted blood samples, and peripheral quantitative computed tomography (pQCT) scans of the tibial metaphysis and diaphysis were collected upon entrance to- and post-training (12 weeks later). Half of the volunteers entered training in July and the other half started in February. Time-by-group interactions were observed for vitamin D status (25OHD) and the bone turnover markers, BAP, TRAP and OCN. 25OHD increased and BAP, TRAP and OCN all decreased in the Ca + D group (p .05). Training increased distal tibia volumetric BMD (+1.9 ± 2.8%), BMC (+2.0 ± 3.1%), and bone strength index (BSI; +4.0 ± 4.0%) and diaphyseal BMC (+1.0 ± 2.2%) and polar stress strain index (SSIp; +0.7 ± 2.1%) independent of Ca + D supplementation (p .05 for all). When analyzed by season, change in BSI was greater in the Ca + D group as compared to placebo in the summer iteration only (T*G; p .05). No other effects of supplementation on bone tissue were observed. When categorized by tertile of percent change in BSI, recruits demonstrating the greatest changes in BSI and 25OHD entered training with the lowest levels of 25OHD (p .05). Over all, these results suggest that Ca + D supplementation reduced some markers of bone formation and resorption and the decline in 25OHD over training in volunteers that started training in the summer was prevented by supplementation. Baseline 25OHD and trajectory may impact bone responses to IMT, but little effect of Ca + D supplementation was observed at the investigated doses.

Introduction The incidence of periprosthetic fractures after total knee arthroplasty (TKA) is rising due to an increasing number of TKAs performed annually and the growing elderly population. Like periprosthetic fractures of the distal femur, periprosthetic tibia fractures are primarily treated with operative fixation; however, there is limited scientific literature that has reported outcomes of periprosthetic tibia fractures treated with modern plating techniques. To our knowledge, this is the largest series of non-intraoperative periprosthetic tibia fractures treated with open reduction internal fixation (ORIF) ever reported. Methods Retrospective chart review of 4557 operatively treated tibia fractures with ORIF over a 16-year period at two Level 1 Trauma Centers. Results 38 patients with an average follow-up of 15.3 months (range 3–24) were identified. 11 (28.9%) fractures were in the proximal tibia (four with extension into the plateau (Felix 1A) and seven adjacent to the tibial stem (Felix 2A)), six (15.8%) in the midshaft/diaphysis (Felix 3A), and 21 (55.3%) in the distal 1/3rd (metaphysis, Felix 3A). 76.3% (29/38) of fractures united by 6 months following the index procedure, leaving 9 nonunions. The overall re-operation rate was 31.6% (12/38). There were no significant differences in rates of union (p = 1.00), reoperation (p = 0.66), superficial infection (p = 0.66), or deep infection (p = 0.31) in patients treated with single versus dual plating. Conclusion Periprosthetic tibia fractures are difficult to treat and have a high risk of nonunion and reoperation even with modern plating techniques. Most patients can be treated to union with operative fixation and do not require revision arthroplasty, if the components are stable initially. We recommend dual plating for fractures in the proximal third, and either single plating or nailing for fractures in the middle and distal thirds depending on bone quality, implant positioning, and fracture morphology.

The proximal humerus is a common, yet understudied site for osteoporotic fracture. The current study explored the impact of prolonged physical activity on proximal humerus bone health by comparing bone properties between the throwing and nonthrowing arms within professional baseball players. The proximal humerus in throwing arms had 28.1% (95% CI, 17.8 to 38.3%) greater bone mass compared to nonthrowing arms, as assessed using dual-energy x-ray absorptiometry. At the level of the surgical neck, computed tomography revealed 12.0% (95% CI, 8.2 to 15.8%) greater total cross-sectional area and 31.0% (95% CI, 17.8 to 44.2%) greater cortical thickness within throwing arms, which contributed to 56.8% (95% CI, 44.9 to 68.8%) greater polar moment of inertia (i.e., estimated ability to resist torsional forces) compared to nonthrowing arms. Within the humeral head and greater tubercle regions, throwing arms had 3.1% (95% CI, 1.1 to 5.1%) more trabecular bone, as assessed using high-resolution magnetic resonance imaging. Three-dimensional mapping of voxel- and vertex-wise differences between arms using statistical parametric mapping techniques revealed throwing arms had adaptation within much of the proximal diaphysis, especially the posterolateral cortex. The pattern of proximal diaphysis adaptation approximated the pattern of strain energy distribution within the proximal humerus during a fastball pitch derived from a musculoskeletal and finite element model in a representative player. These data demonstrate the adaptive ability of the proximal humerus to physical activity-related mechanical loads. It remains to be established how they translate to exercise prescription to improve bone health within the proximal humerus, however, they provide unique insight into the relationship between prolonged loading and skeletal adaptation at a clinically relevant osteoporotic site.

Rapid declines in bone mineral density (BMD) at the knee after spinal cord injury (SCI) are associated with an increased risk of fracture. Evaluation of bone quality using the trabecular bone score (TBS) may provide a complimentary measure to BMD assessment to examine bone health and fracture risk after SCI. The purpose of this study was to assess bone mineral density (BMD) and trabecular bone score (TBS) at the knee in individuals with and without SCI. Nine individuals with complete SCI (mean time since SCI 2.9 ± 3.8 yr) and 9 non-SCI controls received dual-energy X-ray absorptiometry scans of the right knee using the lumbar spine protocol. BMD and TBS were quantified at epiphyseal, metaphyseal, diaphyseal, and total bone regions of the distal femur and proximal tibia. Individuals with SCI illustrated significantly lower total BMD at the distal femur (23%; p = 0.029) and proximal tibia (19%; p = 0.02) when compared with non-SCI controls. Despite these marked differences in BMD from both locations, significant differences in total TBS were observed at the distal femur only (6%; p = 0.023). The observed differences in total BMD and TBS could be attributed to reductions in epiphyseal rather than metaphyseal or diaphysis measurements. The relationship between TBS and duration of SCI was well explained by a logarithmic trend at the distal femoral epiphysis (r2 = 0.54, p = 0.025). The logarithmic trend would predict that after 3 yr of SCI, TBS would be approximately 6% lower than the non-SCI controls. Further evaluation is needed to determine if TBS measures at the knee provide important information about bone quality that is not captured by traditional BMD.

Background Peri-implant fractures occur in association with an implant used to treat a previous injury and that is still attached to the bone. Peri-implant fractures are considered to be relatively "new" fractures and they lack any classification system that is accepted in practice. Generally, the fracture classification systems currently used in our clinical practice were not developed or validated using rigorous scientific evaluation methods. Aim To provide data for a proposed classification of peri-implant femoral fractures. Methods This is an international and multicentre study (12 centres) based on a cohort of consecutive peri-implant fractures with the criterion being: a fracture in any segment of the femur in association with previously-used osteosynthesis material, whether a nail, plate or screws. A proposed system for the classification was tested, based on a topographical classification using alphanumeric coding, following a similar nomenclature to that explained in the "Vancouver-Classification-for-Total-Hip-Arthroplasty-Periprosthetic-Fractures", and classified according to whether the implant is a nail, a screw or a plate, and the location of the fracture in relation to the original implant and the affected femoral segment. The study coordinator performed the first classification exercise, which was discussed subsequently for the study coordinator group to reach a consensus. A descriptive analysis of the fractures was produced. The proportion of peri-implant femoral fractures was estimated, and 95% confidence interval (95%CI) was calculated. Results Between January 2013 and December 2016, data on a total of 143 peri-implant femoral fractures were collected. Only 5 (3.5%) fractures had to be discussed to reach a consensus. The most common peri-implant femoral fractures were located at the diaphyseal segment (#32) and associated with nails or plates: 51%, 73/143, 95%CI:43-59%; at the proximal segment (#31): 39%, 56/143, 95%CI:32-47%; and at the distal femoral segment (#33): 10%, 14/143, 95%CI:6-16%. The highest proportion of peri-implant femoral fractures corresponded to #31-AN (trochanteric and neck area) and #32-CNP (diaphysis fractures distant from the implant, often distal and spiral). Conclusion The proposed classification for peri-implant femoral fractures appears to be useful and easy to accomplish. Future studies will be necessary to validate it and demonstrate the effectiveness of its application in clinical practice.

A ∼1.52 Ma adult upper limb skeleton of Paranthropus boisei (KNM-ER 47000) recovered from the Koobi Fora Formation, Kenya (FwJj14E, Area 1A) includes most of the distal half of a right humerus (designated KNM-ER 47000B). Natural transverse fractures through the diaphysis of KNM-ER 470000B provide unobstructed views of cortical bone at two sections typically used for analyzing cross-sectional properties of hominids (i.e., 35% and 50% of humerus length from the distal end). Here we assess cross-sectional properties of KNM-ER 47000B and two other P. boisei humeri (OH 80-10, KNM-ER 739). Cross-sectional properties for P. boisei associated with bending/torsional strength (section moduli) and relative cortical thickness (%CA; percent cortical area) are compared to those reported for nonhuman hominids, AL 288-1 (Australopithecus afarensis), and multiple species of fossil and modern Homo. Polar section moduli (Zp) are assessed relative to a mechanically relevant measure of body size (i.e., the product of mass [M] and humerus length [HL]). At both diaphyseal sections, P. boisei exhibits %CA that is high among extant hominids (both human and nonhuman) and similar to that observed among specimens of Pleistocene Homo. High values for Zp relative to size (M × HL) indicate that P. boisei had humeral bending strength greater than that of modern humans and Neanderthals and similar to that of great apes, A. afarensis, and Homo habilis. Such high humeral strength is consistent with other skeletal features of P. boisei (reviewed here) that suggest routine use of powerful upper limbs for arboreal climbing.

Background Stress fracture risk is elevated during initial military training (IMT), particularly in lower-extremity bones such as the tibia. Although the etiology of stress fractures is multifactorial, lower bone strength increases risk. Objective The objective of this study was to assess, through the use of peripheral quantitative computed tomography, whether adherence to a dietary pattern rich in calcium, potassium, and protein before IMT is positively associated with bone indexes in young adults entering IMT. Design A cross-sectional analysis was performed with the use of baseline data from 3 randomized controlled trials in Army, Air Force, and Marine recruits (n = 401; 179 men, 222 women). Dietary intake was estimated from a food-frequency questionnaire. A dietary pattern characterized by calcium, potassium, and protein was derived via reduced rank regression and a pattern z score was computed for each volunteer, where higher scores indicated greater adherence to the pattern. At the 4% (metaphysis) and 14% (diaphysis) sites of the tibia, bone mineral content (BMC), volumetric bone mineral density, robustness, and strength indexes were evaluated. Associations between dietary pattern z score as the predictor variable and bone indexes as the response variables were evaluated by multiple linear regression. Results Pattern z score was positively associated with BMC (P = 0.004) and strength (P = 0.01) at the metaphysis and with BMC (P = 0.0002), strength (P = 0.0006), and robustness (P = 0.02) at the diaphysis when controlling for age, sex, race, energy, smoking, education, and exercise. Further adjustment for BMI attenuated the associations, except with diaphyseal BMC (P = 0.005) and strength (P = 0.01). When height and weight were used in place of body mass index, the association with BMC remained (P = 0.046). Conclusions A dietary pattern rich in calcium, potassium, and protein is positively associated with measures of tibia BMC and strength in recruits entering IMT. Whether adherence to this dietary pattern before IMT affects injury susceptibility during training remains to be determined. These trials were registered at clinicaltrials.gov as NCT01617109 and NCT02636348.

Background Biological reconstruction after tumor resection is significant for restoration of limb integrality. However, it is unclear what risk factors influence mechanical complications of patients after extremity sarcoma resection and biological reconstruction. The objective of study was (1) to compare complications between patients receiving inactivated autograft and allograft, (2) to analyze influence of graft type, nonunion and fixation method on mechanical complications for patients after biological reconstruction. Hypothesis We hypothesized allograft, nonunion and fixation method influence occurrence of mechanical complications after biological reconstruction. Materials and methods We retrospectively reviewed 71 patients with sarcomas at the extremity receiving biological reconstruction from January 1999 to November 2015. Eight patients were lost at last follow-up. Sixty-three patients with complete clinical data were recruited into the present study. There were 32 males and 31 females with a mean age of 20.5 ± 14.9 yrs (median, 17 yrs; range, 2–72 yrs). Sixty-one cases had tumors at lower extremity and two at upper extremity. Histological diagnosis was confirmed as forty-five with osteosarcoma, thirteen with Ewing sarcoma and five with chondrosarcoma. Results Forty-four patients were free of disease, sixteen died of disease and three lived with pulmonary metastasis at last follow-up. Twenty-one out of 63 patients (33.3%) had local recurrence requiring surgical treatment. Reconstruction choice (mechanical complications rates were 38.9% for allograft (14/36) versus 14.8% inactivated autograft (4/27)) and nonunion occurrence (yes 58.8% (10/17); no 17.4% (8/46)) had the close relationship with mechanical complication in the univariate analysis. The multivariate analysis revealed fixation method (p = 0.041) and nonunion (p = 0.008) were prognostic factors for mechanical complication of sarcoma resection and biological reconstruction at the extremity. Fourteen of 36 patients receiving massive allograft had a second surgery due to mechanical complication compared to 4 of 27 patients with massive inactivated autograft [38.9%, 14/36 vs. 14.8%, 4/27 (p = 0.05)]. Time to union for diaphysis and metaphysis was not significantly different between allograft and inactivated autograft groups. Discussion Patients receiving massive allograft are prone to suffer from the mechanical complications. Extramedullary plate and nonunion have the tendency of increasing occurrence of mechanical complications of biological reconstruction. Level of Evidence IV; retrospective study.

Introduction Functional orthodontic treatment depends on the stage and duration of intermediate stages of pubertal growth for obtaining optimal results, which is stable over time. Even though there are studies about identification of stages of skeletal maturation, the one that clearly outlines the duration is scarce. The purpose of this study was to determine the stage and duration of intermediate stages of pubertal growth of Indonesian subjects using hand-wrist radiographs. Methods The study samples consisted of hand-wrist radiographs from 220 girls aged 8.0 to 16.9 years and 109 boys aged 9.0 to 16.9 years, which is analyzed for 11 skeletal maturation index (SMI) stages (PP3= [proximal phalanges III, epiphyseal = diaphysis] to Ru [radius union]) using the Fishman method. The duration of intermediate stages of pubertal growth, PP3= to S (ossification of adductor Sesamoid of thumb), S to MP3cap (medial phalanges III, capping of epiphysis to diaphysis), and MP3cap to Ru were evaluated. Statistical analysis was performed using IBM SPSS version 21. Results There were significant differences between girls and boys of PP3= to S, S to MP3cap, and MP3cap to Ru. Even though girls exhibited statistically significant longer duration of pubertal growth compared with boys, no difference in duration was observed between boys and girls for PP3= to MP3cap (P > 0.05), which is considered the ideal time for functional orthodontic treatment. Conclusion It is suggested that functional appliance directed toward growth modification should be initiated in girls much earlier than what is now outlined in the literature to gain its full potential.

Aneurysmal bone cyst (ABC) is a benign but locally aggressive, mostly pediatric neoplasm, with characteristic USP6 gene rearrangement that distinguishes it from a secondary ABC and other primary bone tumors. With the advent of next-generation sequencing (NGS) technology, several hitherto unknown USP6 fusion partners have been identified in ABC. Accordingly, we present a case of an 18-year-old male with a solid sub-periosteal primary ABC in the diaphysis of the left femur. Using an NGS-based assay, we identified SPARC-USP6 fusion, which has not previously been described in ABC. Including our case, the list of currently known USP6 fusion partners in primary ABC include: CDH11, CNBP, COL1A1, CTNNB1, EIF1, FOSL2, OMD, PAFAH1B1, RUNX2, SEC31A, SPARC, STAT3 and THRAP3.

Background Nonoperative management of proximal humeral fractures (PHFs) is the most common treatment, but its functional outcome may improve with early mobilization. In frail osteoporotic patients, quick recovery of prefracture independency is mandatory. This study assessed fracture displacement in PHFs managed with conservative treatment after early mobilization and a home-based self-exercise program. Methods We retrospectively analyzed the radiologic displacement of fracture fragments of PHFs treated conservatively with early mobilization and a home-based self-exercise program. Results Included were 99 patients with 26 one-part, 32 two-part, 32 three-part, and 9 four-part PHFs managed conservatively, followed by early mobilization and a home-based self-exercise program. In the x-ray examinations, the head displaced from varus into valgus 55° ± 23° to 42° ± 22°, in the normal range of anatomic values. The medial hinge displaced from medial to the diaphysis (+1 ± 6 mm) to lateral to the head (−0.6 ± 6 mm). The greater tuberosity displaced cranially from −1 ± 7 mm to 2 ± 5 mm. The Constant score at the 1-year follow-up was 79.69 ± 16.3. Discussion and conclusions The home-based self-exercise program for conservative treatment of PHFs displaces the head-diaphysis angle and the medial hinge toward anatomic reduction, but there is a risk of greater tuberosity cranial displacement. Functional results are fairly good, allowing frail patients to keep on with their independency and life style. Because a large number of patients might need further physiotherapy, the quality of the home-based self-exercises should be supervised.

Purpose To assess plain radiographic morphology of arcuate fractures in order to identify patterns and help shape treatment algorithm for proximal fibula fracture. Methods A search of radiographic reports at a level 1 trauma center from 2014 to 2016 using MONTAGE search software for the phrases “arcuate fracture”, “fibular head avulsion”, or “fibular head fracture” was conducted. Descriptive measurements were obtained including dimensions of the fragment, the displacement of the fragment from its anatomic position, and the orientation of the primary fracture line relative to the axis of the fibular diaphysis in both the sagittal and coronal plane. After review of the measurements and radiographs, fracture patterns were assessed based off previous knowledge previous knowledge of posterior lateral corner (PLC) anatomy. Results Radiographic reports of 48 knees (48 patients) met inclusion criteria. The distance of fractures from the proximal aspect of the fibula averaged 9.25 ± 5.53 mm on AP radiographs, and 9.42 ± 4.89 mm on lateral radiographs. The medial-to-lateral width of the proximal fragment averaged 20.09 ± 7.94 mm on AP radiographs, while the anterior-to-posterior width measured on lateral radiographs averaged 17.53 ± 8.48 mm. Orientation of the primary fracture line was calculated at an average of 23.04 ± 14.95° from the perpendicular on the AP view, and 21.55 ± 17.44° from the perpendicular on the lateral. Maximal displacement at the primary fracture line on the AP view was 4.95 ± 8.49 mm). Maximal displacement on the lateral measured 3.98 ± 7.01 mm. Recurring fracture patterns were identified and described. Assessment revealed 11 (22.9%) pattern 1 fractures, six (12.5%) pattern 2 fractures, 31 (64.58%) pattern 3 fractures, possibly correlating with anatomical features and fracture mechanism. Conclusions These measurements and recurring patterns in our study shows the heterogeneity of the size and displacement of these fracture fragments and demonstrates the need for further studies in order to create an anatomic descriptive classification for arcuate fractures, which could be used for clinically for treatment.

U.S. Army Basic Combat Training (BCT) is a physically-demanding program at the start of military service. Whereas animal studies have shown that increased mechanical loading rapidly alters bone structure, there is limited evidence of changes in bone density and structure in humans exposed to a brief period of unaccustomed physical activity.We aimed to characterize changes in tibial bone density and microarchitecture and serum-based biochemical markers of bone metabolism in female recruits as a result of 8 weeks of BCT.We collected high-resolution peripheral quantitative computed tomographic images of the distal tibial metaphysis and diaphysis (4% and 30% of tibia length from the distal growth plate, respectively) and serum markers of bone metabolism before and after BCT. Linear mixed models were used to estimate the mean difference for each outcome from pre- to post-BCT, while controlling for race/ethnicity, age, and body mass index.91 female BCT recruits volunteered and completed this observational study (age = 21.5 ± 3.3 yrs). At the distal tibial metaphysis, cortical thickness, trabecular thickness, trabecular number, bone volume/total volume, and total and trabecular volumetric bone density (vBMD) increased significantly by 1-2% (all p 0.05) over the BCT period, whereas trabecular separation, cortical tissue mineral density (TMD), and cortical vBMD decreased significantly by 0.3-1.0% (all p 0.05). At the tibial diaphysis, cortical vBMD and cortical TMD decreased significantly (both -0.7%, p 0.001). Bone strength, estimated by micro finite element analysis, increased by 2.5% and 0.7% at the distal tibial metaphysis and diaphysis, respectively (both p 0.05). Among the biochemical markers of bone metabolism, sclerostin decreased (-5.7%), whereas bone alkaline phosphatase, C-telopeptide cross-links of type 1 collagen, tartrate-resistance acid phosphatase, and 25(OH)D increased by 10-28% (all p 0.05).BCT leads to improvements in trabecular bone microarchitecture and increases in serum bone formation markers indicative of new bone formation, as well as increases in serum bone resorption markers and decreases in cortical vBMD consistent with intracortical remodeling. Together, these results demonstrate specific changes in trabecular and cortical bone density and microarchitecture following 8 weeks of unaccustomed physical activity in women.

Background Hyperextension of the femoral component and excessive slope of the tibial component may delay the cam–post engagement in semi-constrained revision total knee arthroplasty (TKA). Further, it may compromise the posterior condylar offset (PCO). No prior study has determined whether a short 50-mm stem, or longer stems (100 mm and 150 mm) lead to less hyperextension of the femoral component or excessive slope and its influence on the posterior condylar offset. Methods Flexion/extension of the femoral component with respect to the sagittal femoral anatomic axis of the distal diaphysis (SFAA) and the tibial slope were measured from rotationally controlled lateral X-rays of 126 consecutive patients with a one- or two-stage revision TKA. Stems of 50 mm, 100 mm and 150 mm were analyzed. Further, reconstruction of the PCO with respect to stem length and component flexion was evaluated. Results The average flexion (+) or extension (−) of the femoral component in the sagittal distal anatomical axis was − 4.1° ± 2.8° (mean ± std) for components, which have been implanted with 50-mm stems and 1.1° ± 1.1° for components with 100- or 150-mm stems, respectively (P = 0.0001). The average slope of the tibial was 2.6° ± 1.5° for tibial trays with 50-mm stems, which was more than the 1.3° ± 1° for trays with 100-mm stems (P = 0.0001). The average PCO ratio was 0.8 ± 1.7 for femoral components with 50-mm stems, which was less than the 1.0 ± 1.7 for trays with 100-mm stems (P = 0.0001). Conclusions Because 50-mm stems resulted in about three degree hyperextension of the femoral component with respect to the SFAA compared to 100-mm or 150-mm stems, the longer stems do not alter the natural femoral flexion and a delay of the cam–post engagement may be avoided. Further, a better reconstruction of the PCO may be archived with the use of longer stems.

Fracture risk increases as type 2 diabetes (T2D) progresses. With the rising incidence of T2D, in particular early-onset T2D, a representative pre-clinical model is needed to study mechanisms for treating or preventing diabetic bone disease. Towards that goal, we hypothesized that fracture resistance of bone from diabetic TallyHO mice decreases as the duration of diabetes increases. Femurs and lumbar vertebrae were harvested from male, TallyHO mice and male, non-diabetic SWR/J mice at 16 weeks (n ≥ 12 per strain) and 34 weeks (n ≥ 13 per strain) of age. As is characteristic of this model of juvenile T2D, the TallyHO mice were obese and hyperglycemic at an early age (5 weeks and 10 weeks of age, respectively). The femur mid-shaft of TallyHO mice had higher tissue mineral density and larger cortical area, as determined by micro-computed tomography, compared to the femur mid-shaft of SWR/J mice, irrespective of age. As such, the diabetic rodent bone was structurally stronger than the non-diabetic rodent bone, but the higher peak force endured by the diaphysis during three-point (3pt) bending was not independent of the difference in body weight. Upon accounting for the structure of the femur diaphysis, the estimated toughness at 16 weeks and 34 weeks was lower for the diabetic mice than for non-diabetic controls, but neither toughness nor estimated material strength and resistance to crack growth (3pt bending of contralateral notched femur) decreased as the duration of hyperglycemia increased. With respect to trabecular bone, there were no differences in the compressive strength of the L6 vertebral strength between diabetic and non-diabetic mice at both ages despite a lower trabecular bone volume for the TallyHO than for the SWR/J mice at 34 weeks. Amide I sub-peak ratios as determined by Raman Spectroscopy analysis of the femur diaphysis suggested a difference in collagen structure between diabetic and non-diabetic mice, although there was not a significant difference in matrix pentosidine between the groups. Overall, the fracture resistance of bone in the TallyHO model of T2D did not progressively decrease with increasing duration of hyperglycemia. However, given the variability in hyperglycemia in this model, there were correlations between blood glucose levels and certain structural properties including peak force.

Background: Femoral bone loss during revision total hip arthroplasty poses a challenging problem. Bypass fixation over the diaphysis has achieved clinical success in cases of proximal femoral bone loss. Fracture of cementless, fully bead-coated femoral stem is an uncommon complication. The purpose of this study is to analyze the patients with and without fracture stem and find out the possible risk factors. Methods: From 2006 to 2012, a total of 251 revision long stems (Zimmer, Warsaw, IN) were implanted. In the same period, 17 broken stems that underwent treatment were included for analysis. Patients' demographic data, pattern of femoral bone loss, stem size, medial calcar support in the proximal region of the stem, and the timing of stem breakage were collected and analyzed. Results: The stem size in patients with a broken stem was smaller (p

Introduction Studies conducted on forearm bone diaphysis nonunion are limited due to the rarity of this condition. The present study aimed to evaluate the outcome of our technique using autologous iliac corticocancellous bone graft fixed by locking plate system for the forearm bone diaphyseal nonunion without infection. Patients and methods We treated eight patients with nonunion of radial or ulnar shaft fracture (four men, four women) aged 38 years (range: 18–52 years) on average. The average follow-up period was 18 months (range: 12–24 months). In our technique, we applied the locking plate to the diaphyseal bone fragment, before grafting the bone block to the nonunion site. After excision of sclerotic ununited bone, the autologous iliac corticocancellous bone was grafted to the defect and fixed with single locking screw. Pain, grip strength, and disabilities of the arm, shoulder, and hand (DASH) score were measured and compared before and 12 months after the surgery. Radiographs were taken at each follow-up, and the time of bony union was determined. Results The mean time to radiological union was 4.2 months (range: 3–6 months), and bony union was achieved in all cases within 6 months. All measured values, visual analog scale, DASH score, and grip strength, were significantly improved at 12 months after surgery (p Conclusions Locking compression plate fixation and autologous iliac corticocancellous bone grafting with a holding locking screw appears to be a reliable primary procedure for nonunion of the forearm diaphyseal fracture without infection. Level of evidence IV; Therapeutic study.

Small animal models, and especially transgenic models, have become widespread in the study of bone mechanobiology and metabolic bone disease, but test methods for measuring fracture toughness on multiple replicates or at multiple locations within a single small animal bone are lacking. Therefore, the objective of this study was to develop a method to measure cortical bone fracture toughness in multiple specimens and locations along the diaphysis of small animal bones. Arc-shaped tension specimens were prepared from the mid-diaphysis of rabbit ulnae and loaded to failure to measure the radial fracture toughness in multiple replicates per bone. The test specimen dimensions, crack length, and maximum load met requirements for measuring the plane strain fracture toughness. Experimental groups included a control group, bisphosphonate treatment group, and an ex vivo deproteinization treatment following bisphosphonate treatment (5 rabbits/group and 15 specimens/group). The fracture toughness of ulnar cortical bone from rabbits treated with zoledronic acid for six months exhibited no difference compared with the control group. Partially deproteinized specimens exhibited significantly lower fracture toughness compared with both the control and bisphosphonate treatment groups. The deproteinization treatment increased tissue mineral density (TMD) and resulted in a negative linear correlation between the measured fracture toughness and TMD. Fracture toughness measurements were repeatable with a coefficient of variation of 12–16% within experimental groups. Retrospective power analysis of the control and deproteinization treatment groups indicated a minimum detectable difference of 0.1 MPa·m1/2. Therefore, the overall results of this study suggest that arc-shaped tension specimens offer an advantageous new method for measuring the fracture toughness in small animal bones.

Background Bone resorption around the femoral stem after total hip arthroplasty is a well-known phenomenon. However, only a few studies have evaluated bone resorption after shoulder arthroplasty. This study investigated the prevalence of humeral bone resorption after different shoulder arthroplasty procedures. Methods The study included 147 shoulders that underwent total shoulder arthroplasty (TSA) or humeral head replacement (HHR) with an uncemented humeral stem from November 2008 to May 2015 and were monitored for more than 1 year. The prevalence of humeral bone resorption and risk factors were investigated. Results The most advanced grade of bone resorption, grade 0, occurred in 21 shoulders (14.3%). Grade 1 bone resorption occurred in 10 (6.8%), grade 2 in 28 (19.0%), grade 3 in 61 (41.5%), and grade 4 in 27 (18.4%). High occurrence of bone absorption was observed in zones 1, 2, and 7. Grade 4 bone resorption did not occur in zones 3 and 5. HHR, on-growth type stem coating, and occupation ratio were significant independent risk factors for grade ≥3 bone resorption, whereas female sex and HHR were significant independent risk factors for grade 4. Conclusion Bone resorption was observed in 126 shoulders (85.7%), and full-thickness cortical bone resorption occurred in 27 shoulders (18.4%). Bone resorption was frequently observed at the greater tuberosity, lateral diaphysis, and calcar region (zones 1, 2, and 7). Significant risk factors included female sex, HHR with rotator cuff reconstruction, on-growth type stem coating, and high occupation ratio of the implant.

Background The study purpose is to evaluate the working length, proximal screw density, and diaphyseal fixation mode and the correlation to fracture union after locking plate osteosynthesis of distal femoral fractures using bridge-plating technique. Methods A four-year retrospective review was performed to identify patients undergoing operative fixation of distal femur fractures with a distal femoral locking plate using bridge-plating technique for the metadiaphyseal region. Primary variables included fracture union, secondary surgery for union, plate working length, and diaphyseal screw technique and configuration. Multiple secondary variables including plate metallurgy and coronal plane fracture alignment were also collected. Results Ninety-six patients with distal femur fractures with a mean age 60 years met inclusion criteria. None of the clinical parameters were statistically significant indicators of union. Likewise, none of the following surgical technique parameters were associated with fracture union: plate metallurgy, the mean working length, screw density and number of proximal screws and screw cortices. However, diaphyseal screw technique did show statistical significance. Hybrid technique had a statistically significant higher chance of union when compared to locking (p = 0.02). All proximal locking screw constructs were 2.9 times more likely to lead to nonunion. Conclusions Plating constructs with all locking screws used in the diaphysis when bridge-plating distal femur locking plates were 2.9 times more likely to incur a nonunion. However, other factors associated with more flexible fixation constructs such as increased working length, decreased proximal screw number, and decreased proximal screw density were not significantly associated with union in this study.

Background The aim of this study was to assess proximal humeral fracture patterns using 3-dimensional computed tomography images and relate them to the normal osseous landmarks and soft-tissue attachments. Methods Forty-eight 3-dimensional computed tomography scans of proximal humeral fractures were retrospectively collected, and the fractures were transcribed onto proximal humeral templates. We analyzed the common location and orientation of the fracture lines, with a focus on fractures of the articular surface, tuberosities, metaphysis, and proximal diaphysis. These fractures were compared with the attachments of the rotator cuff and glenohumeral capsule. Results Fifty-two percent of the fractures involved the articular surface. No fractures passed through the bicipital groove, and fractures were more commonly found on the posterior lesser tuberosity and on the anterior greater tuberosity, coinciding with the intervals between the rotator cuff tendon insertions. Intracapsular fractures of the calcar were more common (68%) than extracapsular fractures (32%). On the anterolateral aspect of the proximal humerus, fractures radiated from the articular margin, vertically down through the tuberosity zone between the rotator cuff footprints, meeting horizontally oriented fractures in the metaphyseal zone. On the posterior aspect, vertical fractures from the tuberosity zone continued downward to the metaphyseal zone adjacent to the infraspinatus and teres minor footprints. Conclusions Fractures of the proximal humerus follow characteristic patterns. Fractures frequently split the greater tuberosity and are closely related to the intervals of the rotator cuff attachments.

Background Although mechanical alignment is critical for optimal function and long-term implant durability, the role of modular stems in achieving ideal alignment is unclear. Methods We identified 319 revision total knee arthroplasty from 2003-2013, for which stem length, stem diameter, and stem fixation method were recorded prospectively. Three-dimensional canal-filling ratio, the product of canal-filling ratio at the stem tip in both the anteroposterior and lateral planes, and alignment were measured radiographically. Results Ideal alignment of the femur was considered to be 95° in the anteroposterior (AP) plane and from 1° of extension to 4° of flexion in the lateral plane, and ideal tibial alignment was considered to be 90° in the AP plane. Even after accounting for difference in stem size and canal-fill, ideal AP alignment was more reliably achieved with press-fit stems. Conclusion Furthermore, increased engagement of the diaphysis and its anatomical axis with canal-filling stems facilitates accurate alignment.

We report the results of physiolysis of the epiphyseal bracket combined with free fat grafting for the treatment of delta phalanx. Thirteen cases (five patients) were included. Mean patient age was 6.6years (range, 4-9). The patients underwent physiolysis in which the epiphyseal bracket was cut and replaced with a free fat graft. The angle between the long axis of the proximal and distal phalanges and the ratio between the width and length of the affected middle phalanx were evaluated on plain radiographs. The range of motion in the fingers was also evaluated. The mean follow-up period was 42.2months (range, 25-61). The mean correction angle was 17.1° (range; 13-23). The mean width-to-length ratio of the affected phalanx was improved from 0.6 to 0.47. The range of motion was maintained at the previous level. Physiolysis by untethering the bracketing epiphysis and free fat grafting can alleviate the angulation of clinodactyly, especially in growing children. It also allows catch-up growth in the middle phalanx.

Ewing’s sarcoma is a common malignant bone tumor seen in 5–15 years age group. It often arises from diaphysis of long bones. Ewing’s sarcoma arising from the ilium is very rare, and it has an unfavourable prognosis. We present a rare case report of Ewings sarcoma of ilium with no metastasis in a two and a half year old boy, who was treated with neoadjuvant chemotherapy followed by surgical excision of the tumor and reconstruction using allograft from the femoral head fixed with multiple k-wires and screw. The patient is disease free at one year follow up and the allograft has taken the shape of growing ilium and excellent functionality and gait with minimal limp. Through this report, we emphasize on the occurrence of Ewings sarcoma in unusual site and resection and reconstruction of the tumor utilizing the allograft.

Intramedullary nailing has become the standard for the treatment of long bones diaphyseal fractures. Modern techniques of locking have further enlarged the primary indications to more proximal and distal fractures relying upon a former correct alignment. Nevertheless, residual deformities are not rare as once the nail has left the narrow diaphyseal canal and comes into the wider metaphysis, it may follow an unwished trajectory. There is also a chance for malreduction in diapyhseal fractures. The more complex the fracture is, the more difficult its reduction, not only for the alignment of the proximal or the distal part of bone in relation to the diaphysis, but also correct rotation and length. In this paper, we analyze recommended techniques to achieve accurate bone fracture reduction, to avoid post-operative deformities combined with correct implant insertion.

Diaphyseal femoral fractures are common and can present as isolated injuries or as part of a polytrauma situation. Management of these fractures requires an understanding of the timing of definitive surgery in systemically unwell patients, as well as the physiologic effects of reaming and instrumentation of the femoral canal. An appreciation of biomechanics of femoral nails, along with other implants, and the nuances of their application is essential in achieving a satisfactory outcome.

Bone is considered to be stronger in compression and weaker in shear. Therefore the study on shear properties of cortical bone is important to identify the fracture behavior of cortical bone. Shear properties of the cortical bone are usually evaluated by torsion testing. During torsion test bone undergoes through a tensile fracture rather than expected spiral fracture. This testing method involves preparation of circular samples which require complex machining operations contrary to the samples in Iosipescu which are much easier to procure. This paper studies the shear behavior of a bovine femoral cortical bone using the Iosipescu test and Finite Element Method (FEM) using commercial based software known as ABAQUS. Load-Displacement curves of the bone have been obtained with the help of FE models of Iosipescu test. The stiffness values of cortical bone have been calculated using the load-displacement curves obtained from the FE simulation. This way stiffness values were evaluated for three different locations of cortical bone diaphysis namely upper, middle and lower locations. The main motive of this analysis is to identify an experimental setup for shear testing of bone which comes in handy and is as accurate as others.

Little is known about the impact behavior of composite fixation plate used in the fracture healing of long bones diaphysis. Hence, this study examined polypropylene composite fixation plates using different glass fibers and measured their biomechanical responses under axial impact loading experimentally and numerically. Short randomly oriented, long unidirectional prepregs and fiber yarn of glass were considered as reinforcements, and fixation plates were fabricated through two different heat-compressing and 3D printing processes. Furthermore, assessing the fixation plate structures impact behavior was carried out using in vitro impact test and finite element analysis (FEA). Impact damping behavior, damage mechanisms, and stress and strain pattern of the composite fixation plate structures were obtained under various bone fractures and impact energies. The impact load-time responses and the failure mechanisms demonstrated that fixation plate structures with more plastic behavior and lower stiffness could act as an initial shock absorber and dampen the transmission of axial impact load by distributing the impact energy over time. Therefore, considering the ability of stress shielding and adequate interfragmentary movement which amplifies bone ossification, the proposed Glass Fiber/PP (GF/PP) composite fixation plates could serve as a proper alternative in orthopedics.

Objectives This study was conducted to evaluate clinically and radiologically the patients for whom compressive and non-compressive intramedullary nails were applied and to analyse the compression effectiveness in adult femur distal diaphysis fractures. Hypothesis The compressive locked nails shortened the union period in the distal diaphysis fractures, and it was found to be an effective method, as the pseudoarthrosis rate was lower. Material and methods A retrospective study was conducted among 59 patients for whom the compressive and non-compressive IMNs were applied to treat femur distal diaphysis fractures. Thirty-one for whom the non-compressive IMN was applied were categorised as group I, and 28 for whom the compressive nail was applied were categorised as group II. Finite element analysis was performed using 1.5 mm compression, and a mean stress value of 34.67 Mpa. Results The mean values of union period were calculated as 13.6 ± 2.4 weeks (range: 11–20 months) and functional score was 79.2, respectively in group I, and they were evaluated as a good grade. In group II, the respective mean values of union period were 11.5 ± 2.6 weeks (range: 10–17 months) and functional score was 86, and they were evaluated as excellent. Conclusion Radiological and functional scores were determined to be better with interlocking compressive nails and shortened the fracture union period in the follow-up in adult femur distal diaphysis fractures. Level of evidence III; retrospective cohort study.

Objectives This study was conducted to evaluate clinically and radiologically the patients for whom compressive and non-compressive intramedullary nails were applied and to analyse the compression effectiveness in adult femur distal diaphysis fractures. Hypothesis The compressive locked nails shortened the union period in the distal diaphysis fractures, and it was found to be an effective method, as the pseudoarthrosis rate was lower. Material and methods A retrospective study was conducted among 59 patients for whom the compressive and non-compressive IMNs were applied to treat femur distal diaphysis fractures. 31 for whom the non-compressive IMN was applied were categorised as Group I, and 28 for whom the compressive nail was applied were categorised as Group II. Finite element analysis was performed using 1.5 mm compression, and a mean stress value of 34.67 Mpa. Results The mean values of union period were calculated as 13.6 ± 2.4 weeks (range: 11–20 months) and functional score was 79.2, respectively in Group I, and they were evaluated as a good grade. In Group II, the respective mean values of union period were 11.5 ± 2.6 weeks (range: 10–17 months) and functional score was 86, and they were evaluated as excellent. Conclusion Radiological and functional scores were determined to be better with interlocking compressive nails and shortened the fracture union period in the follow-up in adult femur distal diaphysis fractures. Level of evidence III; retrospective cohort study.

Background Cementless modular endoprostheses with tapered fluted stems cover a wide spectrum of femoral defects in reconstructive surgery of the hip. Nevertheless, for these hip stems the recommendations concerning the minimum diaphyseal anchorage distance differ widely. The present experimental study investigated the primary stability of a conical fluted revision stem depending on different types of femoral bone defects. Methods Using six fresh frozen human femora, the relative movement of a bi-modular revision stem within the implant-bone interface was examined under cyclic loading conditions. Implant subsidence as well as micromotions at the bone-implant interface were captured with linear variable differential transformers for the intact femora and three different defects ranging from Paprosky type II to type IIIB. Findings Compared to the intact femur, the infliction of a Paprosky type IIIB defect (3 cm of intact diaphysis) notably increased mean stem subsidence (13–389 μm per 500 load cycles; P = 0.116) but the mean interface micromotion vector sum remained unchanged (50 μm vs. 53 μm). In Paprosky IIIB defects the subsidence component resulting from rotation (horizontal plane) was significantly higher than with the intact femur and a Paprosky II defect (P ≤ 0.041). Interpretation With optimal bone quality and ideal femur preparation a 3 cm conical fixation was sufficient to meet the set criteria of bony ingrowth in vitro. A conical fixation of 7 cm should be recommended to limit rotational subsidence, especially in case of impaired diaphyseal bone quality or expected difficulties with partial weight-bearing.