DONOR LEG MORBIDITY AND FUNCTION AFTER FIBULA FREE-FLAP MANDIBLE RECONSTRUCTION

The purpose of this study was to determine the donor leg morbidity and function after removal of the fibula free flap for mandible reconstru ction. In the past 24 months, 29 consecutive patients underwent a tota l of 30 fibula free flap mandible reconstructions. A muscle-sparing te chnique was used to harvest the fibula flap, and the proximal 6 cm and distal 8 cm of fibula were left intact. Patients included 20 men and 9 women; their mean age was 58.8 years (range 29 to 82 years); the mea n length of fibula removed was 14.5 cm (range 8 to 25 cm); osteocutane ous flaps were used in 27 patients (90 percent); and 16 patients (53 p ercent) required skin grafts to the donor leg. Donor leg morbidity and function were determined by patient questionnaire, physical examinati on, and isokinetic testing, with the opposite, unoperated leg serving as a control. Immediate postoperative morbidity occurred in 5 patients (17 percent) (infection, wound separation, or partial graft loss); no ne required additional surgery for donor complications. Patient questi onnaires were completed by all patients at an average of 7.3 months af ter surgery. Patients were able to ambulate pain-free an average of 5. 1 weeks (range 2 to 32 weeks) postoperatively and were all fully able to engage in all daily and recreational activities. Most (21 patients, 72 percent) were free of any donor pain, and the remainder (28 percen t) had only occasional mild discomfort. Other complaints included ankl e stiffness (41 percent), mild ankle instability (10 percent), and tra nsient peroneal motor (7 percent) or sensory (28 percent) loss, which resolved in all patients. Isokinetic testing was performed in 11 repre sentative patients an average of 8.4 months after their fibula flap ha rvest. There were no significant differences between operated and cont rol legs in the range of motion of the knee or in ankle eversion/inver sion. However, donor legs had significantly less range of motion in an kle flexion/extension (29 percent decrease; p = 0.003) than controls. Ah strength measurements at the knee and ankle revealed a significantl y decreased strength in the donor leg compared with the unoperated con trol leg. These values ranged from a low of 14 percent (p = 0.02) decr ease in knee flexion/extension strength to a high of 49 percent decrea se (p = 0.002) in ankle eversion strength. While these decreases were significant, the questionnaire results indicate they were not severe e nough to have an impact on patients' daily activities. There was no co rrelation between any subjective or measured patient morbidity and pat ient age, length of fibula harvested, or the use of a skin graft. This study demonstrates that there is a measurable morbidity associated wi th harvest of the free fibula flap which nearly all patients will tole rate well and should not alter lifestyle but which is detectable with isokinetic testing. Patients should be apprised of this morbidity, and strategies to further minimize this morbidity are presented.