Aims. Currently, periprosthetic fractures are excluded from the American Society for Bone and Mineral Research (ASBMR) definition of atypical femoral fracture (AFFs). This study aims to report on a series of periprosthetic femoral fractures (PFFs) that otherwise meet the criteria for AFFs. Secondary aims were to identify predictors of periprosthetic atypical femoral fractures (PAFFs) and quantify the complications of treatment. Patients and Methods. This was a retrospective case control study of consecutive patients with periprosthetic femoral fractures between 2007 and 2017. Two observers identified 16 PAFF cases (mean age 73.9 years (44 to 88), 14 female patients) and 17 typical periprosthetic fractures in patients on bisphosphonate therapy as controls (mean age 80.7 years (60 to 86, 13 female patients). Univariate and multivariate analysis was performed to identify predictors of PAFF. Management and complications were recorded. Results. Interobserver agreement for the PAFF classification was excellent (kappa = 0.944; p < 0.001). On univariate analysis compared with controls, patients with PAFFs had higher mean body mass indices (28.6 kg/m. 2. (. sd. 8.9) vs 21.5 kg/m. 2. (. sd. 3.3); p = 0.009), longer durations of bisphosphonate therapy (median 5.5 years (IQR 3.2 to 10.6) vs 2.4 years (IQR 1.0 to 6.4); p = 0.04), and were less likely to be on alendronate (50% vs 94%; p = 0.02) with an indication of secondary osteoporosis (19% vs 0%; p = 0.049). Duration of bisphosphonate therapy was an independent predictor of PAFF on multivariate analysis (R. 2. = 0.733; p = 0.05). Following primary fracture management, complication rates were higher in PAFFs (9/16, 56%) than controls (5/17, 29%; p = 0.178) with a relative risk of any complication following PAFF of 1.71 (95% confidence interval (CI) 0.77 to 3.8) and of reoperation 2.56 (95% CI 1.3 to 5.2). Conclusion. AFFs do occur in association with prostheses. Longer duration of bisphosphonate therapy is an independent predictor of PAFF. Complication rates are higher following PAFFs compared with typical PFFs, particularly of reoperation and infection. Cite this article: Bone Joint J 2019;101-B:1285–1291

Aims. The incidence of atypical femoral fractures (AFFs) continues to increase. However, there are currently few long-term studies on the complications of AFFs and factors affecting them. Therefore, we attempted to investigate the outcomes, complications, and risk factors for complication through mid-term follow-up of more than three years. Methods. From January 2003 to January 2016, 305 patients who underwent surgery for AFFs at six hospitals were enrolled. After exclusion, a total of 147 patients were included with a mean age of 71.6 years (48 to 89) and 146 of whom were female. We retrospectively evaluated medical records, and reviewed radiographs to investigate the fracture site, femur bowing angle, presence of delayed union or nonunion, contralateral AFFs, and peri-implant fracture. A statistical analysis was performed to identify the significance of associated factors. Results. The mean follow-up period was 70.2 months (36 to 191). There were 146 AFFs (99.3%) in female patients and the mean age was 71.6 years (48 to 89). The AFFs were located in the subtrochanter and shaft in 52 cases (35.4%) and 95 (64.6%), respectively. The preoperative mean anterior/lateral femoral bowing angles were 10.5° (SD 5.7°)/6.1° (SD 6.2°). The postoperative mean anterior/lateral bowing values were changed by 8.7° (SD 5.4°)/4.6° (SD 5.9°). Bisphosphonates had been used contemporarily in 115 AFFs (78.2%) for a mean of 52.4 months (1 to 204; SD 45.5) preoperatively. Nailing was performed in 133 AFFs (90.5%), and union was obtained at a mean of 23.6 weeks (7 to 85). Delayed union occurred in 41 (27.9%), and nonunion occurred in 13 (8.8%). Contralateral AFF occurred in 79 patients (53.7%), and the use of a bisphosphonate significantly influenced the occurrence of contralateral AFFs (p = 0.019). Peri-implant fractures occurred in a total of 13 patients (8.8%), and a significant increase was observed in cases with plating (p = 0.021) and high grade of postoperative anterolateral bowing (p = 0.044). Conclusion. The use of a bisphosphonate was found to be a risk factor for contralateral AFF, and high-grade postoperative anterolateral bowing and plate fixation significantly increased the occurrence of peri-implant fractures. Long-term follow-up studies on the bilaterality of AFFs and peri-implant fractures are warranted. Cite this article: Bone Joint J 2021;103-B(11):1648–1655

We performed a retrospective review of all patients admitted to two large University Hospitals in the United Kingdom over a 24-month period from January 2008 to January 2010 to identify the incidence of atypical subtrochanteric and femoral shaft fractures and their relationship to bisphosphonate treatment. Of the 3515 patients with a fracture of the proximal femur, 156 fractures were in the subtrochanteric region. There were 251 femoral shaft fractures. The atypical fracture pattern was seen in 27 patients (7%) with 29 femoral shaft or subtrochanteric fractures. A total of 22 patients with 24 atypical fractures were receiving bisphosphonate treatment at the time of fracture. Prodromal pain was present in nine patients (11 fractures); 11 (50%) of the patients on bisphosphonates suffered 12 spontaneous fractures, and healing of these fractures was delayed in a number of patients. This large dual-centre review has established the incidence of atypical femoral fractures at 7% of the study population, 81% of whom had been on bisphosphonate treatment for a mean of 4.6 years (0.04 to 12.1). This study does not advocate any change in the use of bisphosphonates to prevent fragility fractures but attempts to raise awareness of this possible problem so symptomatic patients will be appropriately investigated. However, more work is required to identify the true extent of this new and possibly increasing problem

Aims. The aim of this study was to evaluate the outcomes of a salvage procedure using a 95° angled blade plate for failed osteosynthesis of atypical subtrochanteric femoral fractures associated with the long-term use of bisphosphonates. These were compared with those for failed osteosynthesis of subtrochanteric fractures not associated with bisphosphonate treatment. Patients and Methods. Between October 2008 and July 2016, 14 patients with failed osteosynthesis of an atypical subtrochanteric femoral fracture were treated with a blade plate (atypical group). Their mean age was 67.8 years (60 to 74); all were female. During the same period, 21 patients with failed osteosynthesis of a typical subtrochanteric fracture underwent restabilization using a blade plate (typical group). Outcome variables included the time of union, postoperative complications, Harris Hip Score, and Sanders functional rating scale. Results. In the atypical group, union was achieved in 12 patients (85.7%) at a mean of 8.4 months (4 to 12). The mean follow-up was 31.2 months (12 to 92) The plate broke in one patient requiring further stabilization with a longer plate and strut-allograft. Another patient with failure of fixation and varus angulation at the fracture site declined further surgery. In the typical group, union was achieved in 18 patients (85.7%) at a mean of 7.9 months (4 to 12). There was no difference in the mean Harris Hip Score between the two groups (83.1 points vs 86.8 points; p = 0.522) at the time of final follow-up. Sanders functional rating scores were good or excellent in 78.6% of the atypical group and in 81.0% of the typical group. Conclusion. The 95° angled blade plate was shown to be an effective fixation modality for nonunion of atypical subtrochanteric fractures with a high rate of union and functional improvement, comparable to those after fractures not associated with bisphosphonate treatment. Cite this article: Bone Joint J 2018;100-B:1511–17

Introduction. Atypical femoral fracture focused on relation of bisphosphonate use, frequently. However, the mechanism of atypical femoral fracture was not yet clarified. Atypical femoral fractures have been kept femoral shaft cortical thickness and BMD, practically. We hypothesized that atypical femoral fractures were associated with impaired bone quality and curvature of femoral shaft. Materials & Methods. We experienced four atypical femoral fractures. One was subtrochanteric and three were shaft fracture. Two cases received bisphosphonate therapy for 3–5 years. BMD, bone metabolic markers, and bone quality markers were evaluated. Histomorphometry and collagen cross-link analysis were performed. Curvature of femoral shaft and 3-D finite element analysis in one incomplete fracture case were assessed. Results. BMD values were either maintained or not severely decreased. Deterioration of bone quality were verified by the results of histomorphometry, collagen cross-link analysis, and bone quality maker. Especially, homocystine values, such as one of bone quality markers, were increased in all cases. All atypical femoral shaft fractures showed outward curvature of femoral bone. In one case of incomplete atypical femoral shaft fracture, stress was concentrated at the fracture region according 3-D finite element analysis. Conclusions. The results of this study suggest that atypical femoral fractures were estimated associated with deterioration of bone quality and curvature of femoral shaft

Introduction. Since the concept of severely suppressed bone turnover (SSBT) after long-term bisphosphonate (BPs) use, SSBT have been believed as the major cause of low-energy femoral fractures, which are called atypical femoral fractures. Here we present several cases of stress fractures with bowing femoral shaft deformity, which can be another cause of low-energy femoral fractures in the elderly. Materials and Methods. From 1998 to 2012, we treated thirteen cases of low-energy fractures of femoral shaft. All cases were females with an average age of 77.0 (67–88) years. Retrospectively, we assessed fracture type, X-ray of contralateral side, bowing deformity of femur, and duration of BPs use. Result. All cases were classified as simple fracture; AO/OTA type 32-A. In eleven cases, incomplete fracture of contralateral side was found by X-ray and confirmed by a bone scintigram. In twelve cases, obvious bowing deformity of the femoral shaft was noted. BPs were used only in seven cases, and the medication period was not so long. Just one case had taken Alendronate for ten years, and this case showed no bowing deformity. Discussion. Shane defined atypical femoral fracture, and indicated that the same fractures may develop even without BPs use. According to this definition, our advocating stress fractures by bowing deformity will also be included in atypical fractures. We think stress fractures by bowing deformity should be discriminated from atypical fractures by SSBT

Atypical femoral fractures (AFFs) are reported in patients taking bisphosphonates (BPs). This study aims to describe demographics, potential risk factors and outcome of fixation in AFFs. Forty-three patients with AFF were identified retrospectivity from all identified patients with subtrochanteric or diaphyseal fractures within NHS Grampian between 2008–2018. Patients were identified via hospital coding and electronic search of patients undergoing femoral fixation. AFFs were diagnosed by the 2014 American Society of Mineral and Bone Research diagnostic criteria by electronic patient record review by two investigators. Within this cohort, the incidence of AFF was 8.25% with male to female ratio of 10:1 and a mean of presentation age 73.3 years. 27.9% of AFFs occurred in the diaphysis. 22% of AFFs were bilateral. Mean follow-up was 11.5 months. 87.5% of patients had documented prodromal symptoms. 35% had proven radiological changes before fracture. All patients identified were on BPs. Duration of BPs before fracture was 5 months- 13.2 years (mean 6.3 years). Concurrent use of BPs with steroid and proton pump inhibitors was seen in 58.5%. All patients had intramedullary fixation with 8 (18.6%) requiring revision for non-union. For those that united radiologically it took on average 304 days (220–513). BPs were only stopped in 45% of patients after fixation. AFFs in this cohort appear to be associated with BP use, female sex, clinical and radiological prodrome. AFF remain a difficult clinical problem with a high revision rate. Further work is required to identify the temporal relationships and to raise awareness to improve surveillance/management