Review Question - QID 3167

The femoral neck fracture seen in Figure A is considered by most to be a surgical emergency in a 25-year old due to the at risk blood supply of the femoral head. Due to the intra-capsular hematoma and hemarthrosis that occurs, the involved extremity is often found to be in external rotation and flexion as the intra-capsular volume is the highest in this position. Debate exists of the significance of the pressure caused by the fracture hemarthrosis as it is believed by some to cause a local compartment syndrome adding further insult to the already tenuous blood supply. Advocates of early fixation have proposed that reduction maneuvers without capsulotomy can compromise the circulation of the femoral head by increasing the hip joint pressure. Maruenda et al showed in their study of 34 consecutive patients with femoral neck fractures that the mean intracapsular pressure was the highest with the hip in extension and internal rotation.

Bonnaire et al in their prospective study of 55 patients with intracapsular femoral neck fractures found the lowest pressure to be at 70 degrees of flexion. Both Maruenda and Bonnaire's studies showed no significant intracapsular pressure difference based on fracture displacement.

Corollary to adult fracture patients, it is also noted that pediatric patients with a septic hip hold their hip in a flexed and externally rotated position to maximize intracapsular volume as shown in Illustration A.