[Functional chimeric perforator flap of medial femoral condyle for osteochondral and soft tissue reconstruction in hand and foot joints].

Abstract

Objective: To evaluate the effectiveness of free medial femoral condyle (MFC) functional chimeric perforator flap (FCPF) transplantation in reconstructing joint function by repairing concomitant osteochondral defects and soft tissue defect in hand and foot joints.

Methods: A retrospective analysis was performed on 6 patients (5 males, 1 female; mean age of 33.4 years, range 21-56 years) with traumatic osteochondral joint defects and associated tendon, nerve, and soft tissue defects treated between January 2019 and November 2024. Defect locations included metacarpal heads (n=2), metacarpophalangeal joint (n=1), first metatarsal head (n=1), base of first proximal phalanx (n=1), and talar head (n=1), with soft tissue defects in all cases. Osteochondral defect sizes ranged from 1.5 cm×1.2 cm×0.7 cm to 4.0 cm×0.6 cm×0.6 cm, and skin defects ranged from 4 cm×3 cm to 13 cm×4 cm. The stage Ⅰ treatment included debridement, antibiotic-loaded bone cement filling of bone-cartilage defects, fracture internal fixation, and coverage with vacuum sealing drainage. Stage Ⅱ involved harvesting a free MFC- FCPF included an osteochondral flap (range of 1.5 cm×1.2 cm×0.7 cm to 4.0 cm×0.6 cm×0.6 cm), gracilis and/or semitendinosus tendon grafts (length of 4-13 cm), saphenous nerve graft (length of 3.5-4.0 cm), and a perforator skin flap (range of 6 cm×4 cm to 14 cm×6 cm), each with independent vascular supply. The flap was transplanted to reconstruct joint function. Donor sites were closed primarily or with skin grafting. Flap survival was monitored postoperatively. Radiographic assessment was used to evaluate bone/joint healing. At last follow-up, the joint function recovery was assessed.

Results: All 6 MFC-FCPF survived completely, with primary healing of wounds and donor sites. All patients were followed up 6-44 months (mean, 23.5 months). The flaps at metacarpophalangeal joint in 1 case and at ankle joint in 1 case were treated with degreasing repair because of their bulky appearance, while the other flaps had good appearance and texture. At 3 months after operation, the visual analogue scale (VAS) score for pain during joint movement of recipient site was 0-2, with an average of 0.7; at last follow-up, the VAS score of the donor site was 0-1, with an average of 0.3. According to the Paley fracture healing scoring system, the osteochondral healing of all the 6 patients was excellent. The range of motion of the metacarpophalangeal joint in 3 cases was 75%, 90%, and 100% of contralateral side respectively, the range of motion of the metatarsophalangeal joint in 2 cases was 65% and 95% of contralateral side respectively, and the range of motion of the ankle joint in 1 case was 90% of contralateral side. The hand function was evaluated as excellent in 2 cases and good in 1 case according to the upper limb function evaluation standard of the Chinese Medical Association Hand Surgery Society, and the foot function was evaluated as excellent in 2 cases and fair in 1 case according to the Maryland foot function score of 93, 91, and 69, respectively. The International Knee Documentation Committee (IKDC) score of 6 knees was 91-99, with an average of 95.2.

Conclusion: The free MFC-FCPF enables precise anatomical joint reconstruction with three-dimensional restoration of tendon, nerve, capsule, and soft tissue defects, effectively restoring joint function and improving quality of life.