Donor-site morbidity of the pedicled rectus femoris muscle flap

Abstract

The rectus femoris muscle flap is well known for its reliable anatomy, the ease with which it can be harvested, and its great versatility. As a pedicled or free flap, it is used to cover soft-tissue defects and to recreate motor function. Although the muscle is very reliable, it is not well respected because of its assumed donor-site morbidity, such as weakened knee extension force and decreased range of motion of the knee. To date, these clinical assumptions have only rarely been quantified in terms of objective scores, concerning force deficit and functional or aesthetic outcome. From 1995 to 2002, the authors treated 24 patients with pedicled rectus femoris muscle flaps. Fourteen patients were followed up. Follow-up time ranged from 3 to 56 months postoperatively. The results were evaluated by a standard questionnaire in which pain in relation to walking distance, subjective feeling of weakness, sensibility disorders, everyday function, and aesthetic aspects were assessed. Range of motion in the hip and the knee was measured. For objective verification of a decrease of maximal voluntary contraction force of the remaining quadriceps muscle and for detecting differences in true muscular capacity and voluntary activation, 10 patients with unilateral rectus femoris flaps were tested using the twitch interpolation technique. The authors' patients assessed the remaining function and the aesthetic result of the thigh as at least satisfactory. Two patients complained about pain and weakness in the thigh. Eight patients reported hypesthesia in the lateral suprapatellar region. The maximal voluntary contraction and true muscular capacity values were reduced by 21.8 percent and 18 percent, respectively, when compared with the healthy leg. The range of motion in the knee and hip was not influenced by muscle harvesting. The twitch interpolation technique revealed a mild voluntary activation deficit, probably caused by inhibitory regulation in the spinal cord. In conclusion, donor-site morbidity of the rectus femoris muscle flap is evident but well compensated. There is no decrease in active range of motion in the knee and hip. Patient satisfaction with the functional and aesthetic outcome was high.