Session VII Pelvis and Acetabulum

The Superior Gluteal Artery in the Extended Iliofemoral Approach

Mark C. Reilly, MD, Joel M. Matta, MD, Steven Olson, MD, Paul Tornetta, III, MD

Good Samaritan Hospital, Los Angeles, CA; UC Davis Medical Center, Sacramento, CA; Kings County Hospital, Brooklyn, NY

Purpose: Although injury to the superior gluteal artery following fracture of the acetabulum has been described, its incidence is unknown. Furthermore, it has not been proven that the combination of a superior gluteal artery injury and the use of an extended iliofemoral approach to the acetabulum guarantees abductor muscle necrosis. Routine angiography prior to use of the extended iliofemoral approach may not be justified.

Materials and Methods: Between 1980 and 1992, 86 extended iliofemoral approaches were performed by the senior author for the treatment of fractures of the acetabulum. A review of these patients revealed gradual recovery of abductor function and no evidence of abductor muscle necrosis. In 1992, a prospective protocol was established in which the patency of the superior gluteal artery was determined by intraoperative Doppler examination both prior to and following reduction and fixation of the posterior column fracture. Three institutions followed the same protocol for preoperative evaluation, choice of surgical approach, technique of exposure and post-operative followup. Abductor function was assessed at each follow -up visit after an initial 3 month recovery period.

Results: 41 patients had fractures of the acetabulum treated between November, 1992 and January, 1995 with the use of the extended iliofemoral approach. No patients had pre-operative angiograms performed. The majority (88%) of the patients had associated fracture patterns with 49% being associated both column injuries. Associated extremity, head, chest and abdominal injuries were identified in 69% of patients. Unstable pelvic ring injuries were identified in 22%. All fractures involved the posterior column and all but 2 fractures had displacement of the greater sciatic notch. The average displacement of the notch was 2.5 cm (Range 6mm to 60mm). Neurologic injury was seen in 20% of patients overall with 3 sciatic and 2 peroneal injuries identified.

Intraoperative doppler examination of the superior gluteal artery was performed subsequent to reduction and fixation of the posterior column. Pulsatile flow was confirmed in 40 of 41 patients. All patients were followed for a minimum of 6 months with an average follow-up of 1.3 years. At most recent follow-up no patients had evidence of complete loss of abductor function. 63% of patients had achieved 4/5 motor strength and 25% had achieved 5/5 motor strength. Because motor strength can improve for up to two years post-operatively, these findings may underestimate the true distribution of recovery of function. Five patients had achieved only 3/5 motor recovery but 1 had significant post-traumatic arthritis, 2 have had less than 1 year follow-up and 1 patient has had a superior gluteal nerve injury.

Conclusion: Doppler examination of the superior gluteal vessels provides a means of determining the patency of the artery. No instances of superior gluteal artery laceration or thrombosis were encountered in these 41 patients despite significant fracture displacement involving the sciatic notch. The incidence of superior gluteal artery injury was significantly less than would be expected from prior studies. Massive abductor necrosis resulting from superior gluteal artery injury combined with an extended approach is described based on animal and cadaver studies only. With no instances of this complication in over 120 cases, we cannot support the recommendation of preoperative angiographic study of all patients undergoing acetabular fracture surgery via an extended approach. Arteriograms are useful in the control of hemodynamic instability, but the presence of an abnormal superior gluteal arteriogram may not preclude the use of an extended iliofemoral approach.