Knee Donor Site Morbidity Following Harvest of Medial Femoral Trochlea Osteochondral Flaps for Carpal Reconstruction

Purpose This study examines donor site morbidity associated with the medial femoral trochlea (MFT) when used as a donor site for vascularized osteochondral flaps for reconstruction of challenging carpal defects such as proximal pole scaphoid nonunion and advanced Kienbock disease. Methods The retrospective study population included all patients who had undergone MFT flap harvest for scaphoid or lunate reconstruction. Chart review, patient questionnaires, and validated knee function assessment tools were used: International Knee Documentation Committee Subjective Knee Form scores ranged from 0 (maximal disability) to 100 (no disability). Western Ontario and McMaster Universities osteoarthritis index scores ranged from 0% (no disability) to 100% (maximal disability). Magnetic resonance imaging and radiographs were obtained on the donor knee on the majority of patients. Results Questionnaire response rate was 79% (45 of 57 patients). Average patient age was 35 ± 11 years (range, 19–70 years). Average postoperative follow-up was 27 ± 17 months (range, 9–108 months). The indication for MFT flap reconstruction was scaphoid nonunion in 30 patients and Kienbock disease in 15 patients. All 45 patients had a stable knee on examination. Magnetic resonance and radiographic imaging obtained on 35 patients exhibited no pathological changes. Average duration of postoperative pain was 56 ± 59 days (range, 0–360 days); average duration until patients reported the knee returning to normal was 90 ± 60 days (range, 14–360 days). Forty-three of 44 patients would have the same surgery again if needed; overall satisfaction with the surgery was rated as 5 ± 1 (range, 2–5) on a scale from 0 (no satisfaction) to 5 (maximal satisfaction). Average International Knee Documentation Committee score was 96 ± 9 (range, 56.3–100) and the average Western Ontario and McMaster Universities score was 6% ± 16% (range, 0%–68%). Conclusions Medial femoral trochlea osteochondral flap harvest results in minimal donor site morbidity in the majority of patients. Symptoms are time limited. Intermediate-term follow-up demonstrates excellent results in subjective outcome measures. Type of study/level of evidence Therapeutic IV.