Stress fractures of the femoral neck and coxa vara.

BACKGROUND: Theoretically, coxa vara substantially modifies the biomechanical conditions of the femoral neck, increasing the effect of direct muscle pull and leading to fatigue of opposing muscle groups; such modifications would appear to favour the appearance of stress fractures.

METHODS: We studied 22 stress fractures of the femoral neck, 12 in patients with coxa vara (group A) and 10 in patients with a normal neck-shaft angle (group B), to assess the possible influence of the femoral angle in the production of stress fractures.

RESULTS: Intergroup differences were found for age at the appearance of the fracture (younger patients in the coxa vara group) and symptom duration (longer in group A).

CONCLUSIONS: It is suggested that coxa vara predisposes to femoral neck stress-fracture.