Objectives: To examine the viability of the abductor muscles following extensile exposures to the acetabulum in the presence of superior gluteal artery (SGA) or vein (SGV) injury.
Design: In vivo animal study.
Intervention: Twenty-two dogs underwent either an extensile or combined two-incision acetabular approach; either the SGA, the SGV, or no vessel was ligated.
Main Outcome Measurements: Blood flow to the affected gluteal region was evaluated by angiography, laser Doppler flowmetry, and fluorescent microspheres, and histologic and wet weight analyses were performed on the abductor muscles.
Results: Complete ischemic necrosis of the abductor muscles did not occur in any specimen; however, there were statistically significant reductions in immediate postoperative gluteal muscle perfusion (-47 percent, p < 0.01), loss of abductor muscle mass (-41 percent, p < 0.001), and histologic evidence of moderate to severe necrosis in five of seven specimens with extensile exposures and SGA ligation (p = 0.01). Extensile exposure and SGV ligation also caused a significant loss of muscle mass (-25 percent, p < 0.02), with moderate to severe necrosis occurring in four of seven specimens (p < 0.04). Dogs with SGA ligation undergoing the two-incision approach had no significant changes in muscle mass (-3 percent) or perfusion. Moderate to severe necrosis occurred in only one of four specimens.
Conclusions: This study fails to support the hypothesis that extensile approaches to complex acetabular fractures eliminate abductor collateral circulation when performed in the presence of SGA injury.