Study of Atypical Femoral Fracture Cases Coupled in a Multicenter Study

Abstract

: There are several causes of atypical femoral fractures (AFF) in elderly Japanese patients, including longterm bisphosphonate (BP) use or bowed femoral shaft stress fractures, but the available sample size for examining AFF etiology in a single institution is limited. The purpose of this study was to categorize the characteristics of AFF by analyzing the data compiled on patients treated at our hospital and at affiliated institutes. This multicenter, retrospective, observational study included 34 AFF cases (bilateral AFF 10) in one male and 23 female patients (age range 30-90 years, mean age 73.0 years). Evaluation measures included the presence/absence of BP use, duration of BP use, history of other drug use, presence/absence of comorbidities, fracture site, presence/absence of femoral lateral bowing, bone biopsy parameters, and time to bone union. Nineteen patients were prescribed BP for osteoporosis (duration range 4-10 years, mean duration 6.1 years). Subtrochanteric and femoral shaft fractures were seen in 16 and 18 cases, respectively (complete fractures 22, incomplete fractures 12). Femoral lateral bowing (n = 16) occurred with femoral shaft fractures. Mean time to bone union was 9.0 months (complete fractures 11.3 months, incomplete fractures 3.7 months). AFF could be substantially caused by three factors: BP use, drugs other than BP/ comorbidity, and femoral lateral bowing. Twenty four patients were classified as having BP-related-type (n = 2), drug/comorbidity-type (n = 3), lateral bowing-type (n = 2), or mixed-type (n = 17) AFF. AFF etiology cannot be explained by a single cause; thus, a multifactorial etiology, including poor bone quality due to mutual interactions and mechanical stress, seems to be responsible for the occurrence of AFF. Level of evidence: Ⅳ diagnostic

Comparison of Atypical and Osteoporotic Femoral Shaft Fractures in the Elderly: A Multicenter Study

“…There have been reports showing that the long-term use of BPs, steroids, rheumatoid arthritis, femoral lateral bowing, and diabetes mellitus are associated with the risk of AFF [ 1 , 4 , 8 – 12 ]. A multifactorial etiology, including poor bone quality due to mutual interactions and mechanical stress, appears to be responsible for the occurrence of AFF [ 4 , 6 ].…”

“…There have been reports showing that the long-term use of BPs, steroids, rheumatoid arthritis, femoral lateral bowing, and diabetes mellitus are associated with the risk of AFF [ 1 , 4 , 8 – 12 ]. A multifactorial etiology, including poor bone quality due to mutual interactions and mechanical stress, appears to be responsible for the occurrence of AFF [ 4 , 6 ]. In particular, patients with severe lateral bowing of the femur are likely to sustain dynamic stress on the femoral shaft due to axial pressure [ 4 ]; as a result, femoral shat fractures are increased [ 2 – 4 ].…”

“…A multifactorial etiology, including poor bone quality due to mutual interactions and mechanical stress, appears to be responsible for the occurrence of AFF [ 4 , 6 ]. In particular, patients with severe lateral bowing of the femur are likely to sustain dynamic stress on the femoral shaft due to axial pressure [ 4 ]; as a result, femoral shat fractures are increased [ 2 – 4 ]. In surgical treatment, intramedullary nail fixation has been recommended [ 2 ], and plates were previously chosen as the fixation device owing to the technical impracticability of nailing due to bowing of the femur or cortex thickening [ 7 ].…”

“…Atypical femoral fracture (AFF) is a fracture that occurs at the femoral subtrochanteric or shaft region. The occurrence of this type of fracture is associated with the long-term use of bisphosphonates (BPs) and bowed femoral shaft stress fractures [ 1 – 4 ]. It is a common conception that atypical femoral shaft fractures heal poorly [ 1 , 5 ], but there have been few reports comparing patients with AFF and the control group with respect to bone healing times [ 5 ].…”

Endoprosthetic Reconstruction for a Displaced Atypical Femoral Fracture in a Cancer Patient with Poor Prognosis

“…Displaced AFFs are more difficult to treat than incomplete AFFs. Displaced AFFs also can be treated successfully with IMN and discontinuation of BMAs; however, some earlier reports have indicated that revision was required in 46% (7/17) of patients owing to nonunion/delayed union [ 2 ] and that the mean time to bone union was 11.3 months for displaced AFFs [ 9 ]. Another report demonstrated that teriparatide (TPTD) combined with IMN is advantageous, although TPTD is contraindicated in cancer patients with bone metastasis [ 10 ].…”