Background There is increasing evidence suggesting an association between bisphosphonate use and the occurrence of atypical femoral fractures^1,2. The incidence of atypical femoral fractures accounts for less than 1% of hip and femoral fractures overall³.

Objectives The aim of our audit was to assess the prevalence of atypical femoral fractures and adherence to regional (Fracture Reduction in South Central England (FRiSC)) guidelines in our departmental cohort.

Methods We retrospectively reviewed 1,803 patients from the National Hip Fracture Database (NHFD), with femoral fractures admitted to a district general hospital during a 49-month period (January 2007 to February 2011). We studied all subtrochanteric fractures in patients admitted on bisphosphonates. Corresponding hip radiographs were examined for features of atypical fractures according to the American Society for Bone and Mineral Research (ASBMR) diagnostic criteria⁴.

Results The mean age of the patients included was 63. 161 femoral fractures were identified in patients on bisphosphonates; 73 intertrochanteric, 68 intracapsular and 20 subtrochanteric. 151 (93%) of these were in women. Radiographs of the 20 subtrochanteric fractures were reviewed by a consultant musculoskeletal radiologist, and five were classified as atypical according to ASBMR diagnostic criteria.

Positive aspects of the audit: 1. We examined an increasing management problem in patients on long term bisphosphonates for osteoporosis. 2. A large number of fractures were studied. 3. Radiographs were verified by a consultant musculoskeletal radiologist.

Limitations of the audit: 1. We conducted a retrospective review, thereby introducing potential selection bias. 2. The NHFD did not include mid or distal femoral shaft fractures, with possible underestimation of atypical fractures in our cohort.

Audit recommendations: 1. To improve adherence to FRiSC guidelines for inpatient management of atypical fractures 2. To increase awareness, recognition and management of atypical fractures and increase availability of FRiSC guidelines within the trust by including them on the hospital intranet 3. To design an audit tool for a regional audit.

Conclusions Overall, five atypical femoral fractures were found in a cohort of 1,803 patients at our district general hospital. This is 0.3% of the population studied, consistent with the incidence reported in the literature. We found that improvements in adherence to local guidelines for the management of atypical femoral fractures, along with increasing awareness of the nature of these fractures is necessary.

References

1. NeviaserAS, Lane JM, LenartBA, Edobor- OsulaF, LorichDG. Low-energy femoral shaft fractures associated with alendronate use. J OrthopTrauma. 2008 May-Jun;22(5):346-50.

2. SchilcherJ, MichaelssonK, AspenbergP. Bisphosphonate use and atypical fractures of the femoral shaft. N EnglJ Med. 2011 May 5;364(18):1728-37.

3. FDA Drug Safety Communication: Safety update for osteoporosis drugs, bisphosphonates, and atypical fractures.

4. GiustiA, HamdyNA PapapoulosSE. Atypical fractures of the femur and bisphosphonate therapy: a systematic review of case/case series studies. Bone 2010;47:169–80

Disclosure of Interest None Declared