Incidence and medical management of bisphosphonate-associated atypical femoral fractures in a major trauma centre: a retrospective observational study

Prevalence and risk factors for atypical femoral fracture among Lebanese patients with hip and shaft fractures

This retrospective study investigates the prevalence of atypical femoral fractures (AFFs) among patients admitted with hip and shaft fractures at a tertiary referral center in Beirut, Lebanon. We analyzed electronic medical records and radiology studies of patients aged above 40 admitted with hip and shaft fractures between January 2006 and December 2019. Fractures were confirmed by ICD9 or ICD10 codes. All cases were reviewed by radiologists, and AFFs were identified according to the 2013 revised ASBMR criteria. We identified 1366 hip and shaft fracture patients, of which 14 female patients had 19 AFFs. This represents a prevalence of 1.0% among all hip and shaft fractures patients and 1.7% among all female hip and shaft fracture patients. Bilateral AFFs were found in 5 of the 14 patients. Patients with AFF tended to be younger, with a mean age of 74.3 (±8.6) yr compared to 78.0 (±10.6) for patients with non-AFF fractures. A total of 36% of AFF patients had a prior history of non-traumatic fracture at first admission. A high percentage of patients with AFFs reported intake of proton pump inhibitors (42.9%) and glucocorticoids (21.4%). Bisphosphonate exposure was noted in 64.3% of AFF patients. None of the AFF patients were active smokers or consumed alcohol regularly. BMD assessments were available for 7 AFF patients, indicating osteoporosis in 4 and osteopenia in 3 cases. Hip axis length measurements showed no significant difference between AFF patients (N = 7) and sex and age-matched controls (N = 21). The study underlines the prevalence and characteristics of AFFs in Lebanon, which is consistent with the numbers reported in the literature (0.32%-5%). A larger prospective study that includes hospitals across the nation is needed to gain a more comprehensive view of the prevalence of AFFs in the Lebanese population.

Atypical femur fracture in a male without history of bisphosphonate use: a case report

BACKGROUND

Atypical femur fractures are a rare occurrence, especially in bisphosphonate-naïve men, and merit reporting owing to their unusual presentation and clinical implications. This case report highlights a unique instance of atypical femur fractures in a 73-year-old male with no prior bisphosphonate exposure.

CASE PRESENTATION

The patient, a 73-year-old Indian male with no history of bisphosphonate use, presented with left thigh pain and swelling following a minor fall. Radiographic assessment unveiled a closed left mid diaphyseal femoral shaft fracture. Subsequent imaging revealed an impending fracture in the contralateral femur. A comprehensive diagnostic evaluation, encompassing radiographic analysis, laboratory tests, and clinical assessment confirmed the diagnosis. Surgical management via intramedullary nailing was pursued for both fractures. Notably, the patient's medical history was characterized by radiographic manifestations, the infrequent occurrence of atypical femur fractures in men, and associated risk factors. Treatment encompassed anabolic bone therapy employing teriparatide, alongside discontinuation of antiresorptive agents.

CONCLUSIONS

This case underscores the significance of considering atypical femur fractures in older individuals with limited trauma history. It accentuates the role of anabolic agents in the therapeutic regimen and contributes to the evolving understanding of atypical femur fractures. The report underscores the need for vigilant monitoring and tailored management strategies in similar cases, thereby enhancing clinical practice and patient care.

The safety profile of denosumab in oncology beyond the safety of denosumab as an anti-osteoporotic agent: still more to learn

INTRODUCTION

Initially endorsed as an antiosteoporotic agent, denosumab ‒ human monoclonal antibody inhibiting the receptor activator of nuclear factor kappa-B ligand (RANKL)‒ has currently shown an anticancer potential, rationalizing its exploitation in oncology. A prerequisite for leveraging denosumab in oncology is a favorable safety profile.

AREAS COVERED

The present review provides an overview of the adverse events of denosumab in oncology, with a focus on hypocalcemia, medication-related osteonecrosis of the jaw, atypical femoral fracture(s), post-denosumab vertebral fractures, increased risk of infections, and excess of second primary cancer. Representative studies addressing the safety and efficacy of denosumab compared to bisphosphonates in oncology are summarized. Critical gaps in the literature concerning the safety of denosumab in oncology are highlighted as opposed to plenty of available safety data on denosumab as an antiosteoporotic agent.

EXPERT OPINION

Despite the generally acceptable safety profile of denosumab in oncology, many issues remain unresolved. Further research is mandatory to counteract current challenges, namely: (i) validation of risk factors for adverse events; (ii) elucidation of the pathophysiology of the adverse events in search of actionable molecular pathways; (iii) illumination of the association of denosumab with increased risk of infections and/or second primary cancer; (iv) establishment of optimal diagnostic, and therapeutic protocols.

Atypical femur fractures: current understanding and approach to management

Osteoporosis and resulting osteoporotic fractures are responsible for significant morbidity, excess mortality, and health care costs in the developed world. Medical therapy for osteoporosis has been shown in multiple randomized controlled trials to reduce the risk of vertebral and non-vertebral fractures and hip fractures, and in some studies bisphosphonate medications have been associated with improved survival. Although the overall benefit to risk ratio of osteoporosis medications remains favorable, there have been concerns raised about the long-term safety of these treatments. Atypical femur fracture, which is a rare type of fracture that has been associated with the long-term use of potent antiresorptive bone medications, is a potentially devastating consequence of osteoporosis treatment. This paper reviews our current understanding of atypical femur fractures, their relationship to antiresorptive osteoporosis medications, and proposed strategies for management, in order to inform clinical decision making about the optimal use and duration of medical therapy for the treatment of patients with osteoporosis or at high risk for osteoporotic fractures.

Post-operative Rehabilitation of Atypical Femoral Fracture in a Single Center

Objective:

Increasing numbers of reports have described atypical femoral fracture (AFF) in patients being treated with oral bone resorption inhibitors, such as bisphosphonates. Most AFF patients undergo surgical treatment. However, there is little information about post-operative rehabilitation and patient activity levels after surgery for such fractures. Here we report the outcome of surgical treatment and postoperative rehabilitation for AFF at a single center in Japan.

Methods:

We retrospectively reviewed 13 patients (14 AFFs) who underwent surgery at Nagano Matsushiro General Hospital between January 2013 and December 2016. The clinical backgrounds of the patients were evaluated.

Results:

The patients comprised 1 man (1 AFF) and 12 women (13 AFFs). The mean age at surgery was 77.7±7.1 years (mean±SD). Before AFF occurred, 12 of the 13 patients had used bisphosphonates for osteoporosis. An intramedullary nail was inserted in all patients. Partial weight bearing was started on average 2 weeks after surgery, and full weight-bearing gait was permitted on average 3 weeks after surgery. The average time to bone union was 9.9±6.1 months, ranging from 3 to 23 months. None of the patients required additional surgical procedures, including revision surgery for pseudoarthrosis (nonunion) or delayed union. Before AFF, 12 patients walked independently, and 1 patient walked with a single cane. At the final follow-up (mean duration: 34.5±15.7 months), 8 patients could walk independently and 5 patients walked with a single cane.

Conclusions:

We recognized that rigid fixation for AFF supported early weight-bearing gait after surgery.

Atypical Femur Fractures: Review of Epidemiology, Relationship to Bisphosphonates, Prevention, and Clinical Management

Bisphosphonates (BPs) are highly effective in treating osteoporosis and reducing hip, vertebral, and other fractures by as much as 50% to 70%. However, since 2006, atypical femur fractures (AFFs) emerged as potential side effects of BPs and other treatments. These fractures have unusual radiologic features and occur with little trauma. Public concern has led to a >50% decrease in BP usage. AFFs are rare: for each AFF, >1200 fractures, including 135 hip fractures, are prevented. Case definition criteria were updated by the American Society of Bone and Mineral Research in 2014. Many epidemiologic studies have been reported, and although methodologically challenging, generally support a BP-AFF association. However, the magnitude of the association between BPs and AFFs is uncertain: estimates of relative risk for AFFs among BP users vs nonusers range from 1 to 65 with a meta-analysis estimate of 1.7. Although mechanistic studies have proposed several hypotheses explaining how BPs might decrease bone strength, AFF pathogenesis remains uncertain and cannot explain the paradox of efficacy of reduction of common fractures while increasing risk for rare fractures at one site. There are several consistent risk factors, including Asian race (in North America), femoral bowing, and glucocorticoid use, whereas others remain unclear. Consensus is emerging about strategies to prevent AFFs in BP users (including drug holidays after 5 years' use in some patients). In conclusion, AFFs can be devastating, but even under the most pessimistic assumptions, the benefit/risk ratio is highly positive for BPs, particularly during 3 to 5 years of use. As understanding of AFFs increases, it is becoming increasingly possible to maximize BP benefits while minimizing AFF risk.