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.