Current concepts in the management of bisphosphonate associated atypical femoral fractures

Bisphosphonates are a class of drugs used as the mainstay of treatment for osteoporosis. Bisphosphonates function by binding to hydroxyapatite, and subsequently targeting osteoclasts by altering their ability to resorb and remodel bone. Whilst aiming to reduce the risk of fragility fractures, bisphosphonates have been associated with atypical insufficiency fractures, specifically in the femur. Atypical femoral fractures occur distal to the lesser trochanter, until the supracondylar flare. There are a number of the differing clinical and radiological features between atypical femoral fractures and osteoporotic femoral fractures, indicating that there is a distinct difference in the respective underlying pathophysiology. At the point of presentation of an atypical femoral fracture, bisphosphonate should be discontinued. This is due to the proposed inhibition of osteoclasts and apoptosis, resulting in impaired callus healing. Conservative management consists primarily of cessation of bisphosphonate therapy and partial weightbearing activity. Nutritional deficiencies should be investigated and appro-priately corrected, most notably dietary calcium and vitamin D. Currently there is no established treatment guidelines for either complete or incomplete fractures. There is agreement in the literature that nonoperative management of bisphosphonate-associated femoral fractures conveys poor outcomes. Currently, the favoured methods of surgical fixation are cephalomedullary nailing and plate fixation. Newer techniques advocate the use of both modalities as it gives the plate advantage of best reducing the fracture and compressing the lateral cortex, with the support of the intramedullary nail to stabilise an atypical fracture withincreased ability to load-share, and a reduced bending moment across the fracture site. The evidence suggests that cephalomedullary nailing of the fracture has lower revision rates. However, it is important to appreciate that the anatomical location and patient factors may not always allow for this. Although causation between bisphosphonates and atypical fractures is yet to be demonstrated, there is a growing evidence base to suggest a higher incidence to atypical femoral fractures in patients who take bisphosphonates. As we encounter a growing comorbid elderly population, the prevalence of this fracture-type will likely increase. Therefore, it is imperative clinicians continue to be attentive of atypical femoral fractures and treat them effectively.     

与双膦酸盐类药物相关的非典型股骨骨折的研究进展

双膦酸盐类药物是治疗骨质疏松症的常用药物之一。它们的应用大大降低了骨质疏松症相关的椎体、非椎体骨折的发生率。然而,近年来美国食品药品监督管理局发布安全警告:长期使用双膦酸盐可能导致下颌骨坏死、心房颤动、非典型股骨骨折等。最近关于长期应用双膦酸盐与非典型骨折的关系越来越受到关注。这些低能量性骨折也称为脆性骨折。其多发生于股骨转子下或股骨干。目前认为双膦酸盐可能通过长期严重地过度抑制骨转换,导致骨重塑受损,骨微损伤累积,骨脆性增加,从而诱发自发性骨折。女性、亚裔、西班牙裔人种、体重指数、长期应用糖皮质激素、长期应用双膦酸盐且无药物假期被认为是非典型股骨骨折的危险因素。美国骨与矿物质研究学会推荐非典型骨折患者应立即停用双膦酸盐类药物,并予以钙剂、维生素D及特立帕肽治疗;对于完全性骨折患者,建议行股骨全长髓内钉内固定以保护整个股骨。总之,与经典的高能量性骨折相比,非典型股骨骨折具有独特的病理生理学特点、临床表现及影像学特征等。这里我们基于近期研究及文献检索做一综述。     

Outcomes between older adults with atypical and typical femoral fractures are comparable

IntroductionAtypical femoral fractures (AFFs) are rare but a serious complication associated with prolonged use of bisphosphonates. However little is known about clinical outcomes of AFFs. The aim of this study is to compare the characteristics and postoperative outcomes between older patients with AFFs and typical femoral fractures (TFFs).MethodsA retrospective matched cohort study (each AFF was age- and sex-matched with three TFFs) of patients aged 65 years or older who were admitted to The Queen Elizabeth Hospital, South Australia between January 2011 and December 2013 was undertaken. Baseline characteristics of both groups were compared. The primary outcomes evaluated were level of independence in mobility at discharge and 3 months after surgery. Secondary outcomes included length of hospital stay, post-operative complications, rate of surgical revision, discharge destination (after acute hospital stay or rehabilitation), 28-day hospital readmission and 12-month mortality.ResultsTen patients (mean age: 78.1 years) with AFFs were compared with 30 matched TFFs. Patients with AFFs were predominantly female (90%) and 80% had been taking oral bisphosphonate. Nine of the AFFs had their fractures fixed with an intramedullary (IM) nail. The level of independent mobility at discharge (OR 0.31; 95%CI: 0.06–1.71; p = 0.26) and at 3 months (OR 0.51; 95%CI: 0.10–2.53; p = 0.47) were comparable between the two groups. Only one AFF patient treated with plate and screws required surgical revision, compared with none in the TFF group. Secondary outcomes were not significantly different between the two groups.ConclusionRecovery of mobility and reoperation rates after surgery of patients with AFFs were favourable and did not differ significantly from TFFs. Further consideration should be given to using IM fixation in the management of AFFs in older people.     

Retrospective review of patients with atypical bisphosphonate related proximal femoral fractures

IntroductionPatients may be at an increased risk of atypical proximal femoral fractures with prolonged bisphosphonate use.Patients and methodsThis was a retrospective review of patients who sustained a subtrochanteric fracture of the femur in our department between April 2009 and March 2014. The radiographs were reviewed for features of atypical femoral fractures as described by the American Society of Bone Mineral Research.Results185 patients were coded according to the National Hip Fracture Database as having sustained a subtrochanteric fracture of the femur. Of these, 26 patients had radiographic findings consistent with an atypical subtrochanteric fracture. 5 patients were excluded as their histology confirmed malignancy. 12 patients were taking bisphosphonates on admission. All 12 patients were females taking alendronic acid on admission, who sustained the fracture as the result of minimal or no trauma and underwent long gamma nail fixation. The mean age was 71.6 years (range 62–79 years). The mean length of time on bisphosphonates prior to admission was 8.33 years (range 3–25 years). 9/12 patients had pre-existing symptoms for between 5 days and 2 years prior to admission. 1 patient sustained a broken gamma nail 14 weeks post-operatively requiring revision. The mean time to discharge from theatre was 16 days (range 5–57 days). The mean time to radiological union in the patients in whom there was evidence was 24 weeks.ConclusionsIn this small group of patients, management of this fracture pattern can be complex with the potential for delayed or non-union and prodromal symptoms are common.     

Factors affecting fracture location in atypical femoral fractures: A cross-sectional study with 147 patients

IntroductionMany studies have tried to determine the characteristics of atypical femoral fractures (AFFs) through age-, sex-, and ethnicity-matched comparison with non-AFFs. However, we hypothesized that diaphyseal AFFs would have characteristics different from those of subtrochanteric AFFs. The aim of this study was to evaluate the clinical features of diaphyseal/subtrochanteric AFFs and determine the factors related to fracture location.Patients and methodsOne hundred forty-seven patients with AFF were enrolled, 114 patients (78%) had a history of bisphosphonate use. Forty-nine patients (33%) had bilateral lesion, and 35% of patients had thigh pain. Patients were divided into two groups according to fracture location: 52 patients (35.4%) with subtrochanteric AFF and 95 patients (64.6%) with diaphyseal AFF. The patient demographics and fracture characteristics of the two groups were compared. Multivariate logistic regression analysis was used to adjust for variables related to fracture location.ResultsThe patients in the diaphyseal AFFs group were older and had lower BMI, lower BMD, and larger lateral and anterior bowing. Multivariate analysis revealed that age greater than 65 years and low BMD were related with diaphyseal location. With greater lateral bowing angle, the AFF location was moved from the subtrochanteric area to the diaphyseal area.ConclusionThis study demonstrated that patients with diaphyseal AFFs had different characteristics compared with those with subtrochanteric AFFs.     

Surgical outcome of intramedullary nailing in patients with complete atypical femoral fracture: A multicenter retrospective study

BackgroundManagement of atypical femoral fracture on bisphosphonate therapy still remains controversy and is reported high rate of complications. The aim of this study was to evaluate the outcome of intramedullary nailing in patients with atypical femoral fracture who took bisphosphonate more than one year through the multicenter retrospective study.MethodsWe gathered 75 atypical femoral fractures from seven institutions between 2009 and 2014. Among them 46 atypical femoral fractures which met the inclusion criteria was evaluated in this study. The average age was 70.1 years (53–80) and the average duration of bisphosphonate use was 5.1 years (1–15 years). Medical records and radiographs were reviewed to determine time to union, union rate, need for revision surgery, restoration of ambulatory function, and complications.ResultsTwenty-nine (63%) fractures healed within 6 months without complications. The average time to union except two non-union was 24.9 weeks (11–48 weeks). Two patients (4.3%) underwent revision surgery for non-union and there was no implant failure. Thirty-seven (80.4%) patients achieved their pre-fracture ambulatory function at the final follow up.ConclusionsAlthough the incidence of delayed bone healing is high in atypical femoral fracture on bisphosphonate therapy even treated with intramedullary nailing, the incidence of revision surgery and implant failure was relatively lower than those of extramedullary devices.     

Frequency and associated factor of atypical periprosthetic femoral fracture after hip arthroplasty

BackgroundAtypical femoral fracture (AFF) is a serious complication after the use of bisphosphonates, and periprosthetic femoral fracture (PFF) appeared as a common complication after hip arthroplasty, especially in senile patients. Although American Society for Bone and Mineral Research has excluded PFFs from the definition of AFFs, several case reports found PFF patients undergoing bisphosphonate treatment, have fractures resembling AFF and the authors suggested that AFF can also occur in operated femurs after hip arthroplasty. To date, the frequency and risk factors of atypical PFF are unknown. The purpose of our study was (1) to evaluate the proportion of atypical PFF among Vancouver type B PFFs, and (2) to determine the association between occurrence of atypical PFF and use of bisphosphonate.MethodsWe reviewed medical records and radiographs of 67 Vancouver type B PFFs (67 patients) due to low-energy trauma and classified them into atypical PFF group and ordinary PFF group. We calculated the proportion of atypical PFFs among PFFs and identified risk factors for atypical PFF.ResultsAmong the 67 PFFs, 7 fractures (10.4%) were classified as atypical PFF. Longer duration of bisphosphonate use was an independent risk factor of atypical PFF. (Odds ratio 2.600, 95% CI 1.184–5.709, p = 0.017).ConclusionIn accordance with wide use of bisphosphonate, atypical PFFs after hip arthroplasty are not rare anymore. Physicians should suspect the atypical PFF, when they meet low-energy fracture in bisphosphonate users, and radiographs show features of AFF.     

股骨干不典型骨折一例

股骨干不典型骨折是相对于通常股骨干骨折而言的,是指在没有明显暴力外伤情况下发生的骨折,并且排除了骨质疏松性骨折及病理性骨折。本文报道患者在没有暴力外伤、股骨干皮质增厚的情况下发生了股骨干骨折。为什么在没有暴力外伤、股骨干皮质增厚的情况下会发生通常只会发生在有暴力外伤的情况下才会发生的股骨干骨折呢？我们详细回顾了该患者的病史,发现该患者在长期服用抗骨质疏松药福善美,该不典型股骨骨折是否与长期服用福善美有关？本文就此回顾了相关文献,以期提醒临床实践中关注此问题并逐渐明确二者是否相关。     

双膦酸盐相关非典型股骨骨折的手术治疗

目的 探讨手术治疗双膦酸盐相关非典型股骨骨折的疗效。方法 回顾性分析2011年1月至2012年12月手术治疗的15例(15侧骨折)双膦酸盐相关非典型股骨骨折患者资料,平均年龄76.0±6. 4岁(65~88岁)。所有病例骨折时髓部骨密度T值平均为–3. 1±0. 7(–1.8~–4.5)。9病例骨折部位位于转子下,6例位于股骨干。12例采用髓内针固定。3例采用钢板螺钉固定。术后观察患者的骨折愈合情况。结果 所有患者术后均获骨性愈合,平均愈合时间为5.9±1.4个月(4~8个月)。无感染、骨折不愈合,内固定物松动或断裂,下肢深静脉血栓等并发症发生。不同固定方式骨折愈合时间无差异(t=1.56,P=0.14)。服药时间与骨折愈合时间无相关性(r=0.034,P=0.904)。结论 手术治疗是双膦酸盐相关非典型股骨骨折的有效方法。     

Delayed fixation of displaced type II and III pediatric femoral neck fractures

Background:

Time from injury to fixation of femoral neck fractures has been postulated as a vital determinant for rate of complications; however, no prospective study is available in the English literature. Delay, unfortunately, is inevitable in developing countries. The aim of the present study is to retrospectively review the outcome after delayed fixation of displaced type II and III femoral neck fractures in children.

Materials and Methods:

Using a standard assessment chart, we retrospectively reviewed medical records of all pediatric patients having femoral neck fractures presenting to our institution from June 1999 to May 2006. Inclusion criteria were children between 5 and 15 years of age sustaining displaced Delbet type II and III femoral neck fractures having a complete follow-up of at least 2 years. Patients with known metabolic disease, poliomyelitis or cerebral palsy, were excluded from the study. After application of inclusion and exclusion criteria, 22 patients having 22 fractures (13 type II and 9 type III) were studied. Surgery could be performed after a mean delay of 11.22 days (ranging from 2 to 21 days). Closed reduction was achieved in 14 cases and 8 cases required open reduction through anterolateral approach.

Result:

Osteonecrosis was noted in eight patients (36.37%) who included two of nine patients (22.22%) operated in the first week, three of eight patients (37.51%) operated in the second week, and three of five patients (60%) operated in the third week of injury. Nonunion was seen in four (18.18%) cases, and two of them were associated with failure of implants. One was treated by valgus osteotomy and the other by Meyer''s procedure. Fractures united in both children but the latter developed avascular necrosis. Functional results, as assessed using Ratliff''s criteria, were good in 14 (63.63%), fair in 2 (9%), and poor in 6 (27.27%) patients.

Conclusion:

Delay in fixation, type of fracture, and ability to achieve and maintain reduction are factors primarily responsible for the outcome. We also found that delay after the first week further adversely affects the outcome.     

Subtrochanteric fractures after retrograde femoral nailing

Secondary fractures around femoral nails placed for the management of hip fractures are well known. We report, two cases of a fracture of the femur at the interlocking screw site in the subtrochanteric area after retrograde femoral nailing of a femoral shaft fracture. Only a few reports in the existing literature have described these fractures. Two young men after sustaining a fall presented to us with pain, swelling and deformity in the upper thigh region. On enquiring, examining and radiographing them, peri-implant fractures of subtrochanteric nature through the distal interlocking screws were revealed in both patients who also had histories of previous falls for which retrograde intramedullary nailing was performed for their respective femora. Both patients were managed with similar surgical routines including removal of the existing hardware, open reduction and ace cephallomedullary antegrade nailing. The second case did show evidence of delayed healing and was additionally stabilized with cerclage wires. Both patients had uneventful postoperative outcomes and union was evident at the end of 6 mo postoperatively with a good range of motion at the hip and knee. Our report suggests that though seldom reported, peri-implant fractures around the subtrochanteric region can occur and pose a challenge to the treating orthopaedic surgeon. We suggest these be managed, after initial stabilization and resuscitation, by implant removal, open reduction and interlocking intramedullary antegrade nailing. Good results and progression to union can be expected in these patients by adhering to basic principles of osteosynthesis.     

Potential pathogenic mechanism for stress fractures of the bowed femoral shaft in the elderly: Mechanical analysis by the CT-based finite element method

IntroductionStress fractures of the bowed femoral shaft (SBFs) may be one of the causes of atypical femoral fractures (AFFs). The CT-based finite element method (CT/FEM) can be used to structurally evaluate bone morphology and bone density based on patient DICOM data, thereby quantitatively and macroscopically assessing bone strength. Here, we clarify the pathogenic mechanism of SBFs and demonstrate this new understanding of AFFs through mechanical analysis by CT/FEM.Patients and methodsA prospective clinical study was performed from April 2012 to February 2014. We assembled two study groups, the bowed AFF group (n = 4 patients; mean age, 78.0 years) including those with a prior history of AFF associated with bowing deformity and the thigh pain group (n = 14 patients; mean age, 78.6 years) comprising outpatients with complaints of thigh pain and tenderness. Stress concentration in the femoral shaft was analysed by CT/FEM, and the visual findings and extracted data were assessed to determine the maximum principal stress (MPS) and tensile stress–strength ratio (TSSR). In addition, we assessed femoral bowing, bone density, and bone metabolic markers. Wilcoxon's rank sum test was used for statistical analysis.ResultsAll patients in the bowed AFF group showed a marked concentration of diffuse stress on the anterolateral surface. Thirteen patients in the thigh pain group had no significant findings. However, the remaining 1 patient had a finding similar to that observed in the bowed AFF group, with radiographic evidence of bowing deformity and a focally thickened lateral cortex. Patients were reclassified as having SBF (n = 5) or non-SBF (n = 13). Statistical analysis revealed significant differences in MPS (p = 0.0031), TSSR (p = 0.0022), and femoral bowing (lateral, p = 0.0015; anterior, p = 0.0022) between the SBF and non-SBF groups, with no significant differences in bone density or bone metabolic markers.ConclusionsSignificant tensile stress due to bowing deformity can induce AFFs. SBFs should be considered a novel subtype of AFF, and patients with complaints of thigh pain and femoral shaft bowing deformity must be considered at high risk for AFFs.This project (Ref: AOTAP 13-13) was supported by AOTrauma Asia Pacific.     

Surgical strategy of the treatment of atypical femoral fractures

The atypical femoral fracture (AFF) has been attracting significant attention because of its increasing incidence; additionally, its treatment is challenging from biological and mechanical aspects. Although surgery is often required to manage complete AFFs, clear guidelines for the surgical treatment of AFFs are currently sparse. We reviewed and described the surgical treatment of AFFs and the surveillance of the contralateral femur. For complete AFFs, cephalomedullary intramedullary nailing spanning the entire length of the femur can be used. Various surgical techniques to overcome the femoral bowing common in AFFs include a lateral entry point, external rotation of the nail, and the use of a nail with a small radius of curvature, or a contralateral nail. In the case of a narrow medullary canal, severe femoral bowing, or pre-existing implants, plate fixation may be considered as an alternative. For incomplete AFFs, prophylactic fixation depends on several risk factors, such as a subtrochanteric location, presence of a radiolucent line, functional pain, and condition of the contralateral femur; the same surgical principles as those in complete AFFs can be applied. Finally, once AFF is diagnosed, clinicians should recognize the increased risk of contralateral AFFs, and close surveillance of the contralateral femur is recommended.     

Outcome after intramedullary nailing of femoral shaft fractures

Background: The results of intramedullary nailing of femoral shaft fractures from Australian institutions have not been widely reported. This study examines a consecutive group of patients treated at a major metropolitan trauma centre and reports on the injury statistics and outcome data, and compares this to previously reported results from the literature. Methods: A total of 101 fractures in 97 consecutive adult patients were included in the study. Nine patients were excluded. At a minimum of 6 months post injury, 54 patients were interviewed by telephone and 35 patients presented for clinical review and underwent physical examination, computed tomography (CT) scanogram of the lower limbs and Short Form 36 questionnaires. Results: Road trauma accounted for 81% of injuries and 15% of fractures were open. Of the 54 patients reviewed, 13 (23%) required further surgery for delayed or non‐union. Of the 35 who presented for physical examination, there was poor correlation between perceived leg length discrepancy and measured leg length discrepancy on examination or scanogram. Presence of a limp correlated with measured leg length discrepancy of more than 1 cm but did not correlate with rotational abnormality measured on CT scanogram. Pain at the hip, thigh or knee was present in 60% of patients. The Short Form 36 scores for physical functioning, role ? physical, bodily pain, general health and vitality were all significantly lower than population norms with P values ranging from <0.001?0.05. Subgroup analysis comparing isolated femur fracture to multi‐trauma patients for all five of these parameters revealed significant differences only in the multi‐trauma group. Conclusion: The incidence of pain, limp, leg length discrepancy and delayed or non‐union is higher in this study than in previously reported results of intramedullary nailing for femoral shaft fractures. This may be due to differences in the patient population, the skill level of the operating surgeon, or incomplete follow up.     

Incomplete Atypical Femoral Fractures: Assessing the Diagnostic Utility of DXA by Extending Femur Length

Atypical femoral fractures (AFFs) are associated with prolonged bisphosphonate therapy. A feature of incomplete AFF is a localized periosteal reaction. It has been suggested that extending the length of the femur image at the time of dual-energy X-ray absorptiometry (DXA) may diagnose an incomplete AFF. In patients older than 50 yr on bisphosphonate therapy for more than 5 yr, we extended femur length at the time of routine DXA. Abnormal DXA images were suggested in 19 of 257 patients (7.4%). On X-ray, 7 patients (2.7%) showed no abnormality, 7 patients (2.7%) showed evidence of AFF, and 5 patients (2.0%) showed an unrelated radiographic abnormality. Of the 7 cases with X-ray evidence of AFF, 5 had a periosteal flare and 2 had a visible fracture line, both of whom needed insertion of an intramedullary nail. We demonstrated that it is feasible to detect incomplete AFF early using extended femur length imaging with a prevalence in our sample of 2.7% (95% confidence interval: 1.7%–3.7%).     

股骨近端带锁髓内钉联合抗骨质疏松药物治疗高龄不稳定型股骨粗隆间骨折的疗效观察

目的：采用股骨近端带锁髓内钉（ PFN）微创内固定术结合规范抗骨质疏松方案治疗高龄不稳定型股骨粗隆间骨折,评估近期疗效。方法2010年1月至2012年12月,对92例不稳定型股骨粗隆间骨折行微创内固定术治疗,其中男32例,女60例,年龄70～88岁,平均年龄78．5岁。骨折采用Tronzo-Evans分型,其中Ⅲ型46例,Ⅳ型34例,Ⅴ型12例。术前骨密度测量值（ DEXA法）为0.46～0.82 g/cm2,平均0.64±0.16 g/cm^2,均达到严重骨质疏松的诊断标准。固定方式采用股骨近端带锁髓内钉（ PFN）,骨缺损严重者予Wright人工骨粒植入。术后早期床上进行双下肢肌肉锻炼,CPM机辅助治疗。先后给予鲑鱼降钙素、唑来膦酸并补充钙剂、维生素D进行抗骨质疏松治疗。结果所有患者均顺利完成手术,术后无伤口感染等并发症;根据Parker髋关节功能评分,优62例,良22例,一般6例,差2例,优良率91.3％。所有患者均获得12个月以上连续随访,经X线片证实均达到骨性愈合。骨折愈合时间12～18周,平均14.5周,3例患者发生旋转螺钉向后轻度退出。结论 PFN结合抗骨质疏松治疗高龄不稳定型股骨粗隆间骨折,具有创伤小、固定可靠,利于骨折愈合等优点,近期疗效满意。     

Bilateral simultaneous femoral neck fractures in a child

Introduction  Bilateral femoral neck fracture is a rare injury, mostly seen in adults often with bony and metabolic disorders. This injury occurs very rarely in children and only few of it have been reported. Case report  A 4-year-old child with direct pelvic trauma and bilateral femoral neck fractures is reported in whom early surgical treatment was successful. Conclusion  Bilateral femoral neck fracture is extremely rare in children, but in patients with pelvis trauma it should be suspected and the radiograms should be carefully reviewed.     

Plate Fixation for Atypical Fractures of the Femoral Diaphysis

BackgroundPlate fixation for atypical femoral fractures has shown high failure rates compared to intramedullary nail fixation. The aim of this study was to evaluate the radiological results of patients treated with a plate and screws for atypical fractures of the femoral diaphysis.MethodsThis study was conducted retrospectively on 16 patients who had undergone internal fixation using plates for treatment of atypical femoral complete fractures from 2007 to 2015. Nine patients were treated with lag screws and short plates while 7 patients were treated with position screws and long plates, which covered the whole femur. Radiologic evaluation was performed on all patients. Complications were also evaluated.ResultsBone union was achieved in all patients and the average bone union time was 17.7 weeks (range, 14–28 weeks). There was no correlation between the preoperative use of a bisphosphonate, plate length, postoperative teriparatide use, and the time to bone union. Regarding complications, 2 cases of complete fractures and 1 impending fracture occurred at the end of short plates.ConclusionsSatisfactory results were obtained with use of plates for patients with atypical femoral complete diaphyseal fractures, in whom intramedullary nails could not be applied due to severe bowing. In particular, it seemed advantageous compared with intramedullary nail fixation in that it could maintain the leg length through anatomical reduction and prevent iatrogenic fracture.