Femoral Head Excision Arthroplasty Using the Vascularised Rectus Femoris Muscle Sling

SummaryRectus femoris muscle slings were transposed over femoral head ostectomy sites in four large breed dogs, while in three other dogs, standard femoral head and neck excision arthroplasty was performed. After the operation two dogs, with rectus femoris muscle slings, showed transient swelling of the operated limb and remained weight bearing minimally throughout the 28-day study period. In the two remaining dogs with muscle transposition, the surgical sites were normal, but decreased weight bearing and marked lameness were apparent. The dogs with standard femoral head excisions did not have any postoperative problems with the surgical sites and were weight bearing, with slight to moderate gait abnormalities, after the operation. All of the dogs showed decreases in coxofemoral range of motion, standing hip angle and limb length of the operated leg but postoperative differences between the two treatment groups were not significant. Thigh muscle circumference was significantly less in dogs with rectus femoris muscle slings than those with standard femoral head excision. Extensive perfusion of transposed slings was apparent on angiographic studies. Histopathology of muscle slings showed focal inflammation, muscle fibre atrophy and fibrosis with intact neurovascular supply.Femoral head excisional arthroplasty was performed in seven large breed dogs, four of which had adjunctive rectus femoris muscle slings trans-posed over ostectomy sites. Although the rectus femoris muscle sling remained vascular and was associated with minimal immediate postoperative complications, dogs with muscle transposition showed decreased weight bearing, more obvious lameness and a slower return to function, than dogs with standard femoral head and neck excision. Dogs with rectus femoris muscle slings did not show any improvement in coxofemoral range of motion, standing hip angle or limb length, rather more thigh muscle atrophy was evident on day 28 after surgery.