EFFECTS OF SURGICAL APPROACHES FOR ACETABULAR FRACTURES WITH ASSOCIATED GLUTEAL VASCULAR INJURY

Objectives: To examine the viability of the abductor muscles following extensile exposures to the acetabulum in the presence of superior glu teal artery (SGA) or vein (SGV) injury. Design: In vivo animal study. Intervention: Twenty-two dogs underwent either an extensile or combine d two-incision acetabular approach; either the SGA, the SGV, or no ves sel 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 w ere performed on the abductor muscles. Results: Complete ischemic necr osis of the abductor muscles did not occur in any specimen; however, t here were statistically significant reductions in immediate postoperat ive gluteal muscle perfusion (-47 percent, p < 0.01), loss of abductor muscle mass (-41 percent, p < 0.001), and histologic evidence of mode rate to severe necrosis in five of seven specimens with extensile expo sures 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 specimen s (p < 0.04). Dogs with SGA ligation undergoing the two-incision appro ach had no significant changes in muscle mass (-3 percent) or perfusio n. Moderate to severe necrosis occurred in only one of four specimens. Conclusions: This study fails to support the hypothesis that extensil e approaches to complex acetabular fractures eliminate abductor collat eral circulation when performed in the presence of SGA injury.