Atypical Femur Fractures in Patients Treated with Bisphosphonates: Identification, Management, and Prevention

Bisphosphonates and Atypical Femur Fractures: Is the Relationship Causal or Casual?

Bisphosphonates (BPs) are a time-tested drug class with multivariate use cases. They are used in pathologies ranging from osteoporosis to Paget's disease, and also help in accelerated fracture healing. They have been used to treat both benign and malignant lesions of the skeletal system since a long time. However, there have been reports of increased incidences of atypical femoral fractures (AFFs) in patients exhibiting chronic use of bisphosphonates in the past years. This has led to the widespread dissuasion of physicians and practitioners from using the drug class. By means of this review of the literature, the authors aim to investigate the relationship between BP use and its association with AFFs. The review focuses on and elucidates the basic pharmacology of BPs and goes on to illustrate the indications of BPs in various pathologies of the musculoskeletal system, further exploring the effects of BPs on the healing of various bony fractures. The authors also explore the incidences of other pathologies, such as osteonecrosis of the jaw and nephropathies associated with BP use, and elaborate on their features. Through this review, the authors have tried to educate and induce critical thinking on the part of clinicians and medical professionals in regard to prescribing BPs to patients that need them, by keeping in mind the risk-reward relationship that accompanies their use.

Plate osteosynthesis for atypical femoral fractures in patients with severely bowed femurs: comparing short versus long segment fixation - a case series

BACKGROUND

Intramedullary nail fixation is currently the modality of choice in surgical treatment for atypical femoral fractures (AFF). Its uses are limited, however, in severely bowed femurs, narrow medullary canals, or in the presence of thick endosteal callus at the apex of the femoral curve. In these cases, extramedullary plate osteosynthesis is preferred. The consideration when adopting plate osteosynthesis is whether a short or long segment fixation is superior. We hypothesize that a long segment fixation has the potential advantage of protecting the entire length of the femur from future fractures in the adynamic bone. In this series, we present two cases from our institution, with the aims of discussing the benefits and limitations of short versus long segment plate fixation in AFF.

CASE SUMMARY

We report two uncommon cases of bisphosphonate-related AFF in two Asian patients with severe femoral curvature, who were treated with extramedullary plate osteosynthesis at our institution. One patient underwent fixation with a short segment plate osteosynthesis, and the other received a long plate osteosynthesis spanning the proximal to distal femur in an attempt to protect the bone from future fractures. Both patients showed a favourable and uncomplicated course post-surgery, with early return to ambulation and radiographic bone union at follow up.

CONCLUSION

We expect to see an increase in the number of patients with AFF and bowed femurs, especially with the increased usage of bisphosphonates given an ageing Asian population. Surgical treatment with short and long plate osteosynthesis are options with their own advantages and limitations. With the advent of new anatomical plate options, long segment fixation has become more accessible and may be considered in this patient group as it has the potential advantage of protecting the adynamic femur from future fractures. Further studies should be targeted to determine which method of treatment is superior in this particular group of patients.

ATYPICAL FEMORAL FRACTURES DUE TO THE USE OF BISPHOSPHONATES: EPIDEMIOLOGIC STUDY IN A TERTIARY HOSPITAL

Objective:

Show the relationship between atypical femoral fractures and prolonged use of bisphosphonates and analyze the limit of its beneficial use.

Methods:

Retrospective cohort study (level of evidence 2B). From Atypical fracture cases, patients who used bisphosphonates were selected and the time period of their use was analyzed. Additionally, the variables sex, age, and the side most affected were studied.

Results:

Nine atypical femur fractures were found, all associated with the use of bisphosphonates. The average period of use of this medication was nine years (minimum of three years; maximum of 14 years). The patients’ mean age was of 78 years (69-88 years) and all were women, with the right member being the most affected.

Conclusion:

The use of bisphosphonates to prevent osteoporotic fractures has been increasingly frequent and, when used for a prolonged period, it has been related to atypical fractures. Further scientific studies on doses, maximum periods of treatment, and risk-benefit in the indication of these medications are needed to assist in therapeutic management for each case. Level of Evidence II, Retrospective Study.

Bone Fractures Numerical Analysis in a Femur Affected by Osteogenesis Imperfecta

This work presents a non-invasive methodology to obtain a three-dimensional femur model of three-year-old infants affected with Osteogenesis Imperfecta (OI) type III. DICOM^® Files of a femur were processed to obtain a finite element model to assess the transverse, the oblique, and the comminuted fractures. The model is evaluated under a normal walking cycle. The loads applied were considered the most critical force generated on the normal walking cycle, and the analyses considered anisotropic bone conditions. The outcome shows stress concentration areas in the central zone of the diaphysis of the femur, and the highest levels of stress occur in the case of the comminuted fracture, while the transverse fracture presents the lowest values. Thus, the method can be helpful for determining the bone fracture behavior of certain pathologies, such as osteogenesis imperfecta, osteopenia, and osteoporosis.

Is there a familial predisposition to bisphosphonate-induced atypical femoral fractures?

Bisphosphonates are commonly used in the treatment of osteoporosis. Atypical femoral fracture (AFF) is a well-known adverse effect of bisphosphonate use. The importance of genetic factors has been demonstrated in bone quality, bone turnover, and in the response to osteoporosis treatment. Herein, we present two cases of bilateral AFFs after bisphosphonate use for a short period of time in members of the same family (mother and her daughter) and discuss genetic predisposition to bisphosphonate-induced AFFs in the light of literature data.

Osteoporosis treatment rate following hip fracture in a community hospital

Treatment rates for osteoporosis after a major osteoporotic fracture are unacceptably low. We evaluate the effectiveness of an ortho-geriatric team (OGT) in initiating pharmacologic therapy for osteoporosis post-hip fracture. The OGT was able to achieve a higher treatment rate for patients post-hip fracture in comparison to usual care provided by the primary care hospitalist. Potential reasons for delaying or not proceeding with drug therapy include patient concern regarding potential rare side effects of antiresorptive therapy including osteonecrosis of the jaw and atypical femoral fracture. These events however are rare, and in this study, only 3% of hip fractures were atypical femoral fractures.

INTRODUCTION

Currently, a significant care gap for osteoporosis therapy exists post-hip fracture despite advances in pharmacologic therapy. We evaluate the effectiveness of the OGT at the Oakville Trafalgar Memorial Hospital (OTMH), Ontario, Canada, in reducing the care gap and initiating pharmacologic therapy in hip fracture patients prior to hospital discharge. We also evaluated the incidence of atypical femoral fracture (AFF) separately.

METHODS

A retrospective chart review of patients 59 years and older with a hip fracture admitted to OTMH from January 1, 2016, to February 1, 2017, was conducted. The primary outcome was the proportion of hip fracture patients discharged from the hospital with appropriate treatment for their underlying osteoporosis. A sub-analysis was completed reporting the incidence of AFF among older adults.

RESULTS

A total of 197 patients with a hip fracture were identified, 134/197 (68%) patients were seen by the OGT, 98/134 (73%) of these patients were started on pharmacologic therapy prior to discharge, and 120/134 (89%) of patients seen by the OGT were on treatment within 3 months of discharge following assessment in the complex osteoporosis clinic. Sixty-three patients of the 197 (63/197) (32%) of the hip fracture patients were seen by a hospitalist, and treatment rates prior to discharge were 5%. Only 6/197 patients had experienced an AFF during the study period, and all patients with an atypical femoral fracture had been on long-term bisphosphonate therapy. All of the patients with an AFF had thigh or groin pain for several weeks to months prior to the development of the atypical femoral fracture, providing an opportunity to stop therapy and possibly prevent the development of a complete AFF.

CONCLUSION

The OGT was able to initiate anti-osteoporosis therapy in significantly more patients in comparison to usual care, and higher treatment rates are possible with an OGT.

The impact of sequential therapy from short-term teriparatide to denosumab compared with denosumab alone in patients with osteoporotic hip fracture: a 1-year follow-up study

Background

Sequential therapy from bone-forming medication to resorptive agents is reportedly effective for patients with severe osteoporosis. The objective of this study is to determine the impact of implementing short-term teriparatide (TPTD) intervention before denosumab (DMab) therapy compared with DMab therapy alone for 1 year after hip fracture.

Methods

We retrospectively reviewed the medical records and radiographs of patients who were treated due to osteoporotic hip fracture. TPTD was administered to 22 patients for an average of 12.1 weeks after which the intervention was switched to DMab therapy for 12 months (group 1). DMab alone was administered to 16 patients for 12 months (group 2). Bone mineral density (BMD) was evaluated before and after treatment at the 1-year follow-up. The improvement of BMD in hip and spine was compared with the levels of bone turnover marker.

Results

The difference in femoral neck BMD was 0.005 ± 0.04 in group 1 and − 0.014 ± 0.10 in group 2 (p = 0.442). The difference of spine BMD was 0.043 ± 0.05 in group 1 and 0.052 ± 0.06 in group 2 (p = 0.640). BMD of the spine improved significantly in groups 1 and 2 (p < 0.001, p = 0.002). There was no statistical difference in C-terminal telopeptide and osteocalcin level.

Conclusion

Short-term TPTD administration followed by DMab alone was effective only in improving spine BMD. Short-term treatment with TPTD caused mild improvement in femur neck BMD compared with DMab alone. However, further research with a longer duration of TPTD treatment is warranted, as our findings lack statistical significance.