Atraumatic bilateral femur fracture in long-term bisphosphonate use

Femoral Bowing and Femoral Neck-Shaft Angle Evaluation Can Reduce Atypical Femoral Fractures in Osteoporotic Patients: A Scientific Report

Bisphosphonates (BPs) are the mainstay of osteoporosis treatment due to their safety and efficacy. There is evidence that BPs medication may be complicated by atypical femoral fractures (AFFs). Prolonged administration of BPs is even more strongly associated with AFFs. AFF is a relatively rare complication of BPs when taking into account the huge population worldwide that benefits from this pharmacotherapy. AFF is, however, a serious complication of BPs treatment, which includes prolonged healing time and high revision rate when operative treatment is required. Less frequently, AFFs occur even without BPs administration, while these fractures have all the characteristics of “stress” or “insufficiency” fractures. The critical point of view in AFFs pathogenesis seems to be not only the biology of cortical bone, but also the mechanical issue. It has been proven that BPs, glucocorticoids and proton pump inhibitors (PPIs) can cause bone turnover suppression and affect the biological parameter of AFFs pathogenesis. Specific mechanical femoral bone properties predispose to AFFs pathogenesis. Several studies have already reported that increased femoral bowing > 5.25⁰ degrees or decreased femoral neck-shaft angle <125 degrees, are associated with increased risk for diaphyseal and subtrochanteric AFFs respectively, regardless of BPs uptake. If these two parameters are simultaneously present, the probability for AFFs occurrence increases dramatically. Our scientific report, which is based on the current evidence about AFFs, is that if both femoral bowing angle and femoral neck-shaft angle are evaluated before BPs administration, this intervention may reduce the incidence of AFFs. Thus, in cases with excessive lateral femoral shaft bowing or very small femoral neck-shaft angle, the prescription of another anti-osteoporotic treatment than BPs should be recommended. If, however, BPs can’t be avoided, clinicians should be aware of the fact that long-term administration may be implicated with AFFs occurrence. In these cases, short term BPs administration with timely drug holiday between three and five years may be reasonable. Finally, roentgenographic evaluation of both femurs every six months and medical reference in case of any emerging thigh pain are also logical interventions to prevent and reduce AFFs.

Atypical femoral fractures related to bisphosphonate treatment: issues and controversies related to their surgical management

AIMS

Treatment guidelines for atypical femoral fractures associated with bisphosphonates have not been established. We conducted a systematic review of the treatment of atypical femoral fractures first, to evaluate the outcomes of surgical fixation of complete atypical fractures and secondly, to assess whether prophylactic surgery is necessary for incomplete atypical fractures.

MATERIALS AND METHODS

Case reports and series were identified from the PubMed database and were included if they described the treatment of atypical femoral fractures. In total, 77 publications met our inclusion criteria and 733 patients with 834 atypical complete or incomplete femoral fractures were identified.

RESULTS

For complete fractures, internal fixation was predominantly achieved by intramedullary nailing. The mean time to healing post-operatively was 7.3 months (2 to 31). Revision surgery for nonunion or implant failure was needed in 77 fractures (12.6%). A greater percentage of fractures treated with plate fixation (31.3%) required revision surgery than those treated with intramedullary nailing (12.9%) (p < 0.01). Non-operative treatment of incomplete fractures failed and surgery was eventually needed in nearly half of the patients (47%), whereas prophylactic surgery was successful and achieved a 97% rate of healing.

CONCLUSION

Intramedullary nailing is the first-line treatment for a complete fracture, although the risk of delayed healing and revision surgery seems to be higher than with a typical femoral fracture. Non-operative treatment does not appear to be a reliable way of treating an incomplete fracture: prophylactic intramedullary nailing should be considered if the patient is in intractable pain. Radiographs of the opposite side should be obtained routinely looking for an asymptomatic fracture. Bisphosphonates must be discontinued but ongoing metabolic management in the form of calcium and/or vitamin D supplements is advisable. Teriparatide therapy can be considered as an alternative treatment. Cite this article: Bone Joint J 2017;99-B:295-302.

Spontaneous bilateral fracture neck of femur secondary to vitamin D deficiency: a case report

We report a case of a patient who presented with inability to walk for 2 days which was acute in onset, with no history or preceeding trauma. On examination it was found to have stable vitals. Both lower limbs were in the flexed, abducted & externally rotated attitude, with no sensory motor deficit. Radiological investigations revealing osteoporosis and bilateral fracture neck of femur and blood investigations indicated severe vitamin D deficiency.

Osteoporotic Hip and Spine Fractures: A Current Review

Hip and spine fractures represent just a portion of the burden of osteoporosis; however, these fractures require treatment and often represent a major change in lifestyle for the patient and their family. The orthopedic surgeon plays a crucial role, not only in the treatment of these injuries but also providing guidance in prevention of future osteoporotic fractures. This review provides a brief epidemiology of the fractures, details the surgical techniques, and outlines the current treatment guidelines for orthopedic surgeons.

Bilateral femur fractures associated with short-term bisphosphonate use

Bisphosphonates are the most commonly prescribed drugs to treat osteoporosis because they have been proposed to prevent bone loss. Nevertheless, in up to 0.1% of patients, long-term use may cause atypical stress or insufficiency femoral fractures. Bilateral femoral shaft fractures have been reported after long-term use of bisphosphonates; however, there is limited evidence of the effect of short-term use. The current study reports a case of bilateral femoral fractures after a low-energy fall in a 56-year-old woman and provides a review of the literature on bilateral femoral shaft fractures after long-term use of bisphosphonates. Patients should be educated about the potential for stress fractures with the use of this treatment. In patients with thigh pain, a thorough history and physical examination, including the contralateral thigh, may be beneficial to detect bilateral traumatic or atypical stress fracture patterns. More studies with larger sample sizes are necessary to better identify patients who may be at risk for fracture, including histomorphometric evidence of low bone turnover in patients with unfortunate bilateral cases.

Bisphosphonate long-term treatment related bilateral subtrochanteric femoral fracture. Can teriparatide be useful?

Long-term treatment with bisphosphonates has been related to atypical femoral fractures. We report the clinical case of a woman who suffered a proximal diaphyseal oblique fracture of the left femur after uninterrupted 13-year treatment with alendronate. Shortly after surgery, a painful lytic image in the external cortex of her right femur diaphysis was detected. Some papers have suggested surgical treatment to repair femur fractures after long-term treatment with bisphosphonates. Otherwise, two studies have shown healing acceleration of bone fractures with teriparatide. A lytic lesion was treated with teriparatide obtaining progressive disappearance of symptoms as well as bone healing. This outcome may suggest a way of prevention of complete fractures in symptomatic patients with long-term treatment with bisphosphonates.

Atypical incomplete femoral fractures in asymptomatic patients on long term bisphosphonate therapy

OBJECTIVES

Progression of an incomplete atypical femoral fracture (IF) to a complete fracture in patients on long term bisphosphonate (BP) therapy can be catastrophic. We aimed to determine the frequency and imaging features of IF in asymptomatic patients on long-term BP therapy and to identify distinguishing clinical and laboratory markers in the subset of patients who develop these fractures.

MATERIAL AND METHODS

From August 2009 to March 2011, 220 femoral radiographs in 110 asymptomatic patients (101 women, 9 men, age 47-94) were reviewed by 2 radiologists. All patients were on BP therapy for at least 3 years and had no history of hip/thigh pain or recent trauma. MRI was performed when a fracture was suspected on radiographs. Bone mineral density, serum calcium, 25-hydroxy vitamin D, intact parathyroid hormone, serum c-telopeptide and urine n-telopeptide were obtained in all patients.

RESULTS

Two of 110 patients (1.82%, confidence interval of 0.6% to 6.3%) had 3 IFs. Both patients, age 50 and 57, were Caucasian, active and on BP for 8 years. MRI confirmed radiographic findings in both patients. Both women had T-scores in the osteopenic range at 2 sites and osteoporotic range at 1 site.

CONCLUSION

The 1.82% frequency of IF in asymptomatic patients on long term BP therapy is higher than that suggested in the literature. Statistical differences between fracture and non-fracture groups were not presented as the patient population was too small to draw any significant conclusions.

Oral bisphosphonates are associated with increased risk of subtrochanteric and diaphyseal fractures in elderly women: a nested case-control study

OBJECTIVES

To evaluate the association between bisphosphonate use and the risk of atypical femoral fractures among women aged 65 or older.

DESIGN

Nested case-control study.

SETTING

General practice research database in Spain.

EXPOSURES

Use of oral bisphosphonates before the occurrence of atypical fractures among cases or the corresponding index date among controls. Bisphosphonate use was categorised as ever versus never users. Ever users were divided according to the total time since first prescription.

MAIN OUTCOME MEASURES

Cases were defined as women aged 65 years or older with a first diagnosis of subtrochanteric or diaphyseal fracture, recorded in the BIFAP database between 1 January 2005 and 31 December 2008, and with at least 1 year of follow-up before the index date. For each case, five age-matched and calendar-year-matched controls without a history of hip or atypical fracture were randomly selected from the database.

STATISTICAL ANALYSIS

OR of atypical femoral fracture by bisphosphonate use was determined using conditional logistic regression. Models were adjusted for comorbidities and use of other medications.

RESULTS

The analysis included 44 cases and 220 matched controls (mean age, 82 years). Ever use of bisphosphonates was more frequent in cases than controls (29.6% vs 10.5%). In multivariate analyses, OR (95% CI) of atypical femoral fracture was 4.30 (1.55 to 11.9) in ever versus never users of bisphosphonates. The risk increased with long-term use, with an OR of 9.46 (2.17 to 41.3) comparing those using bisphosphonates over 3 years versus no users (p for trend=0.01).

CONCLUSIONS

Bisphosphonate use was associated with an increased risk of subtrochanteric or diaphyseal fractures in elderly women in a low fracture risk population, with a higher risk among long-term bisphosphonate users.

Microindentation for in vivo measurement of bone tissue material properties in atypical femoral fracture patients and controls

Atypical femoral fractures (AFF) associated with long-term bisphosphonates (LTB) are a growing concern. Their etiology is unknown, but bone material properties might be deteriorated. In an AFF series, we analyzed the bone material properties by microindentation. Four groups of patients were included: 6 AFF, 38 typical osteoporotic fractures, 6 LTB, and 20 controls without fracture. Neither typical osteoporotic fractures nor controls have received any antiosteoporotic medication. A general laboratory workup, bone densitometry by dual-energy X-ray absorptiometry (DXA), and microindentation testing at the tibia were done in all patients. Total indentation distance (Total ID), indentation distance increase (IDI), and creep indentation distance (Creep ID) were measured (microns). Age-adjusted analysis of covariance (ANCOVA) was used for comparisons. Controls were significantly younger than fracture groups. Bisphosphonate exposure was on average 5.5 years (range 5 to 12 years) for the AFF and 5.4 years (range 5 to 8 years) for the LTB groups. Total ID (microns) showed better material properties (lower Total ID) for controls 36 (± 6; mean ± SD) than for AFF 46 (± 4) and for typical femoral fractures 47 (± 13), respectively. Patients on LTB showed values between controls and fractures, 38 (± 4), although not significantly different from any of the other three groups. IDI values showed a similar pattern 13 (± 2), 16 (± 6), 19 (± 3), and 18 (± 5). After adjusting by age, significant differences were seen between controls and typical (p < 0.001) and atypical fractures (p = 0.03) for Total ID and for IDI (p < 0.001 and p < 0.05, respectively). There were no differences in Creep ID between groups. Our data suggest that patients with AFF have a deep deterioration in bone material properties at a tissue level similar to that for the osteoporotic fracture group. The LTB group shows levels that are in between controls and both type of fractures, although not statistically different. These results suggest that bisphosphonate therapy probably does not put the majority of patients at risk for AFF.

Atypical femoral fracture after long-term alendronate treatment: report of a case evidenced with magnetic resonance imaging

Postmenopausal osteoporosis is commonly treated with alendronate, one of the bisphosphonates used for the prevention and treatment of osteoporotic fractures. However, the correlation between atypical femoral fractures and long-term bisphosphonate therapy has not been clearly identified. We report here the case of a 69-year-old woman with postmenopausal osteoporosis who presented with an atypical femoral subtrochanteric fracture on magnetic resonance imaging (MRI) confirmation after having received alendronate therapy for about 3 years. The fracture united after refixation and after administration of alendronate was stopped. Several published reports were reviewed, and some clinical characteristics of this atraumatic fracture were revealed, including the clinical symptoms of thigh pain, stress reaction or stress fracture, and transverse fracture with unicortical beak in an area of cortical hypertrophy. In addition to a regular radiographic survey, MRI, which may provide early information, and bone biopsy for pathologic analysis may be used as tools for early detection and final diagnosis. Once an insufficiency fracture is suspected or proved to be related to bisphosphonate, the withholding of bisphosphonate should be highly recommended to enhance fracture healing. Prophylactic fixation should be considered if fracture healing is not good or if the patient cannot tolerate protection of weight-bearing.

Do bisphosphonates cause femoral insufficiency fractures?

In recent years, several reports have suggested an association between the use of bisphosphonates and subtrochanteric insufficiency fractures. Research from animal studies and in some cases from histomorphometric data collected from patients provide evidence of a possible pathophysiological mechanism behind this phenomenon. Despite this, it has not yet been possible to confirm a causal relationship. The small number of cases, the lack of consistency in defining these atypical fractures, the absence of homogeneity between studies, and the fact that most data available are derived from retrospective observational studies, are some of the difficulties encountered in the evaluation of evidence. Despite the proven benefit of bisphosphonates at providing protection against osteoporotic fractures, caution should be used before continuing therapy for longer than 5 years.

Frequency of incomplete atypical femoral fractures in asymptomatic patients on long-term bisphosphonate therapy

OBJECTIVE

The purpose of our study was to determine the frequency and imaging features of atypical femoral fractures in a consecutive asymptomatic patient population on long-term bisphosphonate treatment and search for distinguishing clinical and laboratory parameters in the subset of patients with fractures.

SUBJECTS AND METHODS

Two hundred femoral radiographs in 100 asymptomatic patients (93 women and seven men; age range, 47-94 years; mean age, 69.3 years) were prospectively reviewed by two radiologists. All patients had received bisphosphonate treatment for at least 3 years and had no history of pain or recent trauma. MRI studies were performed when a fracture was suspected on radiographs. Bone mineral density, serum calcium, albumin, 25-hydroxy vitamin D, intact parathyroid hormone (iPTH), serum C-telopeptide, and urine N-telopeptide values were obtained.

RESULTS

Two of 100 patients (2%) had three insufficiency fractures. Both patients, 50 and 57 years old, were white, active, and had been receiving bisphosphonate therapy for 8 years. The patient with bilateral atypical femoral fractures showed typical features of bisphosphonate-related incomplete atypical femoral fractures. MRI confirmed the radiographic findings in both patients. The two patients with incomplete atypical femoral fractures were significantly younger than those without atypical femoral fractures. There were no significant differences among the fracture and nonfracture groups in terms of clinical or laboratory results, except for mean iPTH, which was significantly decreased in the fracture group.

CONCLUSION

The 2% frequency of incomplete atypical femoral fractures in asymptomatic patients on long-term bisphosphonate therapy is higher than suggested in the literature. Aside from age and mean iPTH, there were no significant differences in clinical or laboratory data between the two groups.

Treatment of femoral fracture nonunion after long-term bisphosphonate use

Bisphosphonates are a class of drugs that prevent bone loss by decreasing bone resorption. They represent a major treatment for osteoporosis and other metabolic bone diseases. Recent reports suggest that a potential complication of long-term bisphosphonate therapy may be atypical insufficiency fractures of the femur. Concern exists about delayed union after fracture stabilization in patients taking bisphosphonates.This article describes 2 patients on long-term bisphosphonate therapy treated for atypical femur fractures that failed to heal with intramedullary nailing. Both patients' fractures occurred after at least 4.5 years of bisphosphonate use and displayed classic findings of bisphosphonate fractures reported in the literature, including a subtrochanteric location, presentation after minimal trauma, transverse fracture, no comminution, and cortical beaking. The original fractures were treated at other institutions with intramedullary nails. Subsequently, both patients presented with pain and atrophic nonunion of their fractures. Evaluation included a computed tomography scan of the fracture and a metabolic workup. The patients discontinued bisphosphonate therapy. They were treated with nail removal and definitive plating to achieve compression across the fracture site. Both fractures went on to heal after this treatment with no further complications.The literature currently recommends treating bisphosphonate fractures with an intramedullary nail. Perhaps initial treatment of these fractures should be similar to an atrophic nonunion, involving compression plating to obtain bone-on-bone contact and promote healing. This would address the biologic and mechanical etiologies of the bisphosphonate fracture.

Atypical femoral fractures and bisphosphonate treatment

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.

Femoral stress fractures associated with long-term bisphosphonate treatment

BACKGROUND

Recent studies have described unique clinical and radiographic characteristics of femoral stress fractures or low-energy fractures associated with long-term bisphosphonate therapy. However, it is unclear whether these fractures require subsequent surgery after the initial treatment.

QUESTIONS/PURPOSES

We performed a cohort analysis of bisphosphonate-associated femoral stress fractures to (1) confirm the unique clinical and radiographic findings compared with existing literature, (2) determine whether any patients with completed fractures had no preexisting transverse stress fracture lines, (3) assess the need for additional surgical procedures, and (4) determine whether the hospital length of stay (LOS) differed for patients with prophylactic fixation of stress fractures versus fixation of completed fractures.

METHODS

We retrospectively reviewed 16 patients with 24 diaphyseal and subtrochanteric femoral stress fractures (14) or low-energy fractures (10) who had been on bisphosphonates for 3 to 10 years. Data included demographics, symptoms, medication history, radiographic characteristics, treatment parameters, LOS, and outcome. Minimum followup was 9 months (average, 44.0 months; median, 31 months; range, 9-112 months).

RESULTS

All patients had clinical and radiographic findings similar to those reported in the literature. Two of four patients sustained completed fractures after radiographs failed to reveal transverse lateral fracture lines. None of the 14 prophylactically treated impending fractures progressed or required additional surgery; however, in five of 10 femurs treated after fracture completion, six additional surgeries were performed. The average hospital LOS was shorter in patients who underwent prophylactic fixation (3.8 days) than in patients treated for completed fractures (5.6 days).

CONCLUSIONS

Bisphosphonate-associated stress fractures and completed fractures are unique, possessing subtle characteristic radiographic features. Completed fractures may occur through the thickened bone in the absence of an appreciable transverse stress fracture line. Our observations suggest prophylactic reconstruction nail fixation may avoid fracture completion and may be associated with a shorter hospital LOS and less morbidity than treatment of completed fractures.

LEVEL OF EVIDENCE

Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Periprosthetic Femoral Insufficiency Fracture in a Patient on Long-term Bisphosphonate Therapy

Recent literature shows an association between long-term bisphosphonate therapy and low-energy fractures of the subtrochanteric femur. It is thought that the pharmacology of bisphosphonates and stress characteristics of the sub-trochanteric femur predispose patients on long-term therapy to fracture. There are few reports in the literature of bisphos-phonate-associated periprosthetic fractures with the characteristic fracture pattern. We report a case in a patient with a 10- year history of sustained bisphosphonate use. The patient is a 79-year-old female that developed new thigh pain 9 years following a cemented total hip arthroplasty. Radiographs revealed lateral cortical thickening and a transverse periprosthetic stress fracture of the lateral femoral cortex at the level of the distal stem. This fracture appears consistent with a bisphosphonate-associated insufficiency fracture, demonstrating that this pattern is not isolated to nonarthroplasty patients.

Schaeffer JF, Attarian DE, Wellman SS. Periprosthetic Femoral Insufficiency Fracture in a Patient on Long-term Bisphosphonate Therapy. The Duke Orthop J 2012;2(1):66-69.

[Biphosphonate-induced femoral stress fractures : A new problem and knowledge so far - case report]

During the last several years the treatment of osteoporosis with bisphosphonates has become accepted as a safe and effective procedure. However, recently there have been increasing numbers of reports of rare complications in the literature. Particularly the occurrence of atypical fractures of the femur has become a focus of interest but the problem is insufficiently known and only rarely addressed in the scientific discussion. The case illustrated here and a survey of the important facts in the recent literature highlight essential aspects of long-term bisphosphonate therapy.

Fracture risk associated with continuation versus discontinuation of bisphosphonates after 5 years of therapy in patients with primary osteoporosis: a systematic review and meta-analysis

Purpose:

The risks and benefits of continuing bisphosphonate therapy beyond 5 years in patients with primary osteoporosis have not been well established.

Methods:

We searched MedLine, EMBase, CENTRAL, CINAHL, and AgeLine prior to February 2010. Bibliographies were also searched and experts in the field contacted. The ProQuest Dissertations and Theses database and relevant conference proceedings were searched to identify unpublished or ongoing studies. Two authors independently reviewed search results. Randomized controlled trials and comparative nonrandomized controlled trials examining post-menopausal women or men ≥50 years of age with primary osteoporosis assigned to continue versus discontinue bisphosphonate therapy after ≥5 years of therapy were included. Of 1188 identified articles, three studies (n = 1443) met criteria for inclusion in data synthesis. Data were extracted and risk of bias assessed by two independent reviewers using predefined criteria.

Results:

No statistically significant association was found between fracture incidence and the discontinuation of therapy beyond 5 years for any type of fracture: clinical nonvertebral fracture (relative risk [RR] = 0.97; 95% confidence interval [CI] 0.77–1.23), clinical vertebral fracture (RR = 0.61; 95% CI 0.32–1.19), or morphometric vertebral fracture (RR = 0.90; 95% CI 0.5–1.64). No differences in adverse events were identified between the two groups.

Conclusion:

We found no significant difference in fracture risk or adverse events between postmenopausal women with primary osteoporosis who continued bisphosphonate therapy versus those who discontinued bisphosphonate therapy after 5 years of treatment. However, given the small number and limited quality of available studies, no firm conclusions or recommendations can be made.

Subtrochanteric fractures after long-term treatment with bisphosphonates: a European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, and International Osteoporosis Foundation Working Group Report

This paper reviews the evidence for an association between atypical subtrochanteric fractures and long-term bisphosphonate use. Clinical case reports/reviews and case-control studies report this association, but retrospective phase III trial analyses show no increased risk. Bisphosphonate use may be associated with atypical subtrochanteric fractures, but the case is yet unproven.

INTRODUCTION

A Working Group of the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis and the International Osteoporosis Foundation has reviewed the evidence for a causal association between subtrochanteric fractures and long-term treatment with bisphosphonates, with the aim of identifying areas for further research and providing recommendations for physicians.

METHODS

A PubMed search of literature from 1994 to May 2010 was performed using key search terms, and articles pertinent to subtrochanteric fractures following bisphosphonate use were analysed.

RESULTS

Several clinical case reports and case reviews report a possible association between atypical fractures at the subtrochanteric region of the femur in bisphosphonate-treated patients. Common features of these 'atypical' fractures include prodromal pain, occurrence with minimal/no trauma, a thickened diaphyseal cortex and transverse fracture pattern. Some small case-control studies report the same association, but a large register-based study and retrospective analyses of phase III trials of bisphosphonates do not show an increased risk of subtrochanteric fractures with bisphosphonate use. The number of atypical subtrochanteric fractures in association with bisphosphonates is an estimated one per 1,000 per year. It is recommended that physicians remain vigilant in assessing their patients treated with bisphosphonates for the treatment or prevention of osteoporosis and advise patients of the potential risks.

CONCLUSIONS

Bisphosphonate use may be associated with atypical subtrochanteric fractures, but the case is unproven and requires further research. Were the case to be proven, the risk-benefit ratio still remains favourable for use of bisphosphonates to prevent fractures.

Atypical subtrochanteric and diaphyseal femoral fractures: report of a task force of the American Society for Bone and Mineral Research

Reports linking long-term use of bisphosphonates (BPs) with atypical fractures of the femur led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address key questions related to this problem. A multidisciplinary expert group reviewed pertinent published reports concerning atypical femur fractures, as well as preclinical studies that could provide insight into their pathogenesis. A case definition was developed so that subsequent studies report on the same condition. The task force defined major and minor features of complete and incomplete atypical femoral fractures and recommends that all major features, including their location in the subtrochanteric region and femoral shaft, transverse or short oblique orientation, minimal or no associated trauma, a medial spike when the fracture is complete, and absence of comminution, be present to designate a femoral fracture as atypical. Minor features include their association with cortical thickening, a periosteal reaction of the lateral cortex, prodromal pain, bilaterality, delayed healing, comorbid conditions, and concomitant drug exposures, including BPs, other antiresorptive agents, glucocorticoids, and proton pump inhibitors. Preclinical data evaluating the effects of BPs on collagen cross-linking and maturation, accumulation of microdamage and advanced glycation end products, mineralization, remodeling, vascularity, and angiogenesis lend biologic plausibility to a potential association with long-term BP use. Based on published and unpublished data and the widespread use of BPs, the incidence of atypical femoral fractures associated with BP therapy for osteoporosis appears to be very low, particularly compared with the number of vertebral, hip, and other fractures that are prevented by BPs. Moreover, a causal association between BPs and atypical fractures has not been established. However, recent observations suggest that the risk rises with increasing duration of exposure, and there is concern that lack of awareness and underreporting may mask the true incidence of the problem. Given the relative rarity of atypical femoral fractures, the task force recommends that specific diagnostic and procedural codes be created and that an international registry be established to facilitate studies of the clinical and genetic risk factors and optimal surgical and medical management of these fractures. Physicians and patients should be made aware of the possibility of atypical femoral fractures and of the potential for bilaterality through a change in labeling of BPs. Research directions should include development of animal models, increased surveillance, and additional epidemiologic and clinical data to establish the true incidence of and risk factors for this condition and to inform orthopedic and medical management.

5-Androstene-3β,7β,17β-triol (β-AET) slows thermal injury induced osteopenia in mice: relation to aging and osteoporosis

5-androstene-3β,7β,17β-triol (β-AET), an active metabolite of dehydroepiandrosterone (DHEA), reversed glucocorticoid (GC)-induced suppression of IL-6, IL-8 and osteoprotegerin production by human osteoblast-like MG-63 cells and promoted osteoblast differentiation of human mesenchymal stem cells (MSCs). In a murine thermal injury model that includes glucocorticoid-induced osteopenia, β-AET significantly (p<0.05) preserved bone mineral content, restored whole body bone mineral content and endochondral growth, suggesting reversal of GC-mediated decreases in chondrocyte proliferation, maturation and osteogenesis in the growth plate. In men and women, levels of β-AET decline with age, consistent with a role for β-AET relevant to diseases associated with aging. β-AET, related compounds or synthetic derivatives may be part of effective therapeutic strategies to accelerate tissue regeneration and prevent or treat diseases associated with aging such as osteoporosis.

Bilateral simultaneous femoral diaphyseal fractures in a patient with long-term ibandronate use

Bisphosphonates are the most common medication used to treat patients with documented osteoporosis. Recently, reports have associated long-term bisphosphonate use with low-energy femur fractures. While no definitive mechanism has been associated, bisphosphonate use has been strongly implicated. This article presents the case of a 65-year-old woman with a 2-year history of ibandronate use presenting with simultaneous low-energy femoral shaft fractures. The patient reported prodromal bilateral thigh pain and was seen by a spine surgeon. A review of the literature implicates long-term ibandronate use in low-energy femur fractures. With most of the basic science studies demonstrating suppressed bone turnover after 5 years of treatment with alendronate, the significance of the present case also lies in the relatively short duration of time the patient was on ibandronate before suffering the bilateral femoral shaft fractures. Possible pathophysiology for the fractures includes suppressed bone turnover that may allow microcracks to propagate in cortical bone, which can weaken the bone and possibly predispose it to fractures. Patients who have been on bisphosphonates long term should be questioned about thigh pain and have radiographs of their femurs obtained if pain exists. Furthermore, if a patient presents with a single subtrochanteric or diaphyseal low-energy femur fracture after long-term bisphosphonate use, a radiograph of the contralateral femur should be obtained to assess for a cortical stress reaction.

Atypical fractures of the femur and bisphosphonate therapy: A systematic review of case/case series studies

Atypical fractures of the femur below the lesser trochanter have been reported in patients treated with bisphosphonates. We performed a systematic literature search of case/case series studies to better define the clinical presentation and to identify characteristics that may predispose patients to such fractures. We considered only women treated with a bisphosphonate at a dosing regimen used for the prevention or treatment of osteoporosis and we included also eight own unpublished cases. We identified 141 women with atypical fractures of the femur, mean age of 67.8+/-11.0 years, who were treated with bisphosphonate for 71.5+/-40.0 months (range=3-192 months). The results of this analysis allow identification of patients on bisphosphonate treatment at risk of developing atypical fractures, define fractures better as predominantly insufficiency fractures, illustrate that long-term bisphosphonate treatment is not a prerequisite for their development, recognize the use of glucocorticoids and proton pump inhibitors as important risk factors, but do not provide insights in the pathogenesis of these fractures and raise questions that need to be addressed in properly designed studies.

Adverse effects of bisphosphonates

Use of bisphosphonates has been growing steadily in the last decade. This follows the introduction of simpler dosing regimes, the availability of lower-priced generics, and concerns about the safety of hormone-replacement therapy. Bisphosphonates have a relatively good safety record and are tolerated by the majority of patients, but serious adverse events have been recorded in some cases. Only the most common of adverse effects are robustly observable in clinical trials. In general, studies were not powered to detect effects that were lower in incidence than fractures. This review of adverse events in bisphosphonate-treated patients was based on published information from case reports, case series, claims databases, national databases, surveys, adverse event reporting databases, and single or pooled clinical trials. The most common acute adverse events with bisphosphonates for osteoporosis are gastrointestinal discomfort and acute influenza-like illness. Renal complications are very rare with oral bisphosphonates and rare with i.v. bisphosphonates when used appropriately. Based on our current knowledge, skeletal events in the form of osteonecrosis of the jaw and atypical fragility fractures are rare compared with the risk of osteoporotic fractures, at least in patients with the same risk of fractures as those in the phase III trials. It is biologically plausible that atypical fragility fractures could follow from suppression of bone remodeling, but high-quality studies proving causality are lacking. Physicians are advised to critically reassess BMD and risk profile after 3-5 years of therapy to avoid treatment in patients at low risk.