Factors Affecting the Second Complete Atypical Femoral Fracture after the First Atypical Fracture

Area of Science:

• Orthopedics
• Bone Metabolism
• Pharmacology

Background:

• Atypical femoral fracture (AFF) is a low-energy fracture of the femur.
• Contralateral femur fractures can occur even after initial healing.
• Understanding risk factors for secondary AFF is crucial for patient management.

Purpose of the Study:

• To identify factors influencing complete AFF in the contralateral femur.
• To analyze predictors of secondary complete AFF in patients with incomplete AFF.

Main Methods:

• Retrospective analysis of 111 femurs from 104 AFF cases.
• Classification of contralateral femurs into complete AFF, incomplete AFF, and untreated incomplete AFF.
• Collection of clinical data and multivariate analysis to determine risk and protective factors.

Main Results:

• Incomplete AFF progressed to complete fracture in 37.5% of cases.
• Lateral cortical bone thickening and thigh pain were associated with poorer prognoses.
• Eldecalcitol use post-fracture and prior bisphosphonate/denosumab use were protective; thigh pain was a risk factor for second complete AFF.

Conclusions:

• Eldecalcitol administration after bone union may prevent AFF recurrence.
• Painful incomplete AFF presents a high risk for progression to complete fracture.