Vascularized Medial Femoral Condyle Bone Graft for Resistant Nonunion of the Distal Radius.

BACKGROUND: Nonunion involving the metaphyseal region of the distal radius is exceedingly rare, usually involving co-morbidity. Patients that have failed multiple prior conventional surgical interventions represent an even more difficult subset to treat; this investigation examined the utility of a specially designed free vascularized medial femoral condyle flap consisting of a central structural block graft with an extended corticoperiosteal sleeve to wrap around the junctions.

METHODS: Six patients (5 males, 1 female) with a mean age of 52 years had failed to achieve union involving the distal radius metaphysis after a mean of 3.7 prior surgeries occurring over a mean period of 24 months. Comorbidities included smoking, alcoholism, chronic nutritional deficiency, and prior osteomyelitis. The unique descending genicular artery medial femoral condyle flap designed to address these patients consisted of a central structural block graft in continuity with an extended corticoperiosteal sleeve. The structural block filled the bone defect, and the corticoperiosteal sleeve wrapped around the bone junctions and the neighboring bone margins. The mean flap size was 5.3 (+/- 1.3) cm long by 4.5 (+/- 0.9) cm wide. Pre-operative to post-operative DASH scores were compared using the paired student' s t-test, with p < 0.05.

RESULTS: All flaps achieved union at a mean of 6.8 (+/- 2.1) weeks following surgery, using the criteria of bridging trabeculae on all 3 radiographs: coronal, sagittal, and oblique. The mean pre-operative DASH score of 63 (+/- 10) was statistically significantly different compared to the mean post-operative DASH score of 18 (+/- 8).

CONCLUSIONS: With few alternative solutions able to address this unique and difficult problem, the structural block of vascularized bone with the extended corticoperiosteal sleeve proved able to achieve a union that had failed multiple previous attempts and able to resist reactivation of infection, in a challenging group of patients with comorbidities.