Atypical periprosthetic femoral fractures of the hip: A PRISMA compliant systematic review.

INTRODUCTION: Long-term use of bisphosphonates (BPs) is associated with Atypical Femoral Fracture (AFF). Theoretically, periprosthetic femoral fractures (PFF) should be excluded from the diagnosis of AFF. However, recently several studies reported the occurrence of PPFs around a hip arthroplasty presenting features of an AFF. The present study describes the characteristics of Atypical Periprosthetic Femoral Fracture (APFF) and evaluates the effectiveness of their management through a PRISMA compliant systematic review of the published case reports and series.

MATERIALS AND METHODS: A literature search was performed using "periprosthetic fracture" and "atypical femoral fracture" as keywords. Patients demographics, drug use, clinical and imaging characteristics, stem fixation and classification, management strategies for APFF and patients' outcomes, were also collected.

RESULTS: The present review included and analysed 17 patients from 12 studies. All APFFs occurred in females with a mean age of 75.9 years of age (range 43-87). In 11 patients, APFFs occurred around an uncemented stem, and in 6 around a cemented stem. Ten fractures were incomplete, and 7 complete. Conservative management was effective in 4 of 10 patients with incomplete fracture, while all patients with complete fractures underwent open reduction and internal fixation. A fracture non-union was observed in 5 patients and further surgery was required.

DISCUSSIONS: APFFs share several clinical and imaging characteristics with AFF. An appropriate and early diagnosis may allow to improve the outcome of these fractures, the management of which should be based on the same principles of that of AFFs.

CONCLUSIONS: Considering the low quality of published articles and the heterogeneity of the treatment used, a clear recommendation of the most appropriate treatment cannot be formulated.