Morphological abnormalities of the hip in acetabular fractures.

Poor prognosis factors in surgical treatment of acetabular fracture-dislocations have been well established but there is little information about how morphological abnormalities of the hip may affect the surgical outcome. Hip anatomy has a wide range of variations. Morphological abnormalities of the hip can also be observed in patients with acetabular fractures. We present a case of a complication in a patient with a complex acetabular fracture, acetabular retroversion and femoroacetabular impingement. A 31-year old male patient was transferred to our trauma center following a high speed road traffic accident. Trauma series CT revealed cerebral contusion, subdural hematoma, aortic dissection and a left transverse plus posterior wall acetabular fracture. The left hip was reduced and the acetabular fracture was treated with a Kocher Langenbeck approach in prone position. The pelvic X- ray evidenced an anatomic reduction and signs of acetabular retroversion with positive posterior wall sign and crossover sign. CT scan evidenced increased alpha angle in the femoral head neck junction. During the follow up, 2 months after the acetabular fixation, patient suffered a posterior left hip dislocation and a total cementless hip arthroplasty was performed. Patients with acetabular retroversion and femoroacetabular impingement (CAM lesion) may be at risk of posterior dislocation. The influence of acetabular version and impingement may be also closely involved in how challenging the determination of hip stability can be in patients with posterior wall acetabular fractures. Acetabular retroversion and FAI may be related to the dislocation of unstable patterns with small fragments (wall sizes less than 20%). In this case postoperative precautions were not enough. We believe capsular reattachment with anchors and bracing may be useful in these selected cases. As these patients are not candidates for retroPAO (the recommended treatment for acetabular retroversion) maybe arthroscopic anterior wall riming and CAM resection should be performed at an early stage to decrease or avoid fulcrum.