Physeal-Sparing Medial Femoral Condyle Flap for Treatment of Scaphoid Nonunion With Avascular Necrosis in Skeletally Immature Patients: A Case Series With Long-Term Follow-Up.

BACKGROUND

Scaphoid nonunion is a rare but challenging condition in the pediatric population. While acute scaphoid fractures in children typically heal well with cast immobilization, nonunion can result in persistent pain and functional impairment. The medial femoral condyle (MFC) flap offers potential advantages for reconstruction by providing a robust blood supply and structural support. However, its application in skeletally immature patients is limited by concerns over damaging the open distal femoral physis.

METHODS

We present 2 cases of skeletally immature patients with scaphoid nonunion treated using modified physeal-sparing MFC osseous flaps. The flap was harvested using a pedicle based on the transverse branch of the descending genicular artery to avoid injury to the distal femoral physis. Intraoperative fluoroscopy guided harvest site selection. The flaps were inset to reconstruct the scaphoid defect and secured with cannulated screw fixation. Postoperative immobilization was followed by staged rehabilitation. Long-term clinical and radiologic outcomes were assessed, including patient-reported outcome measures.

RESULTS

Both patients achieved radiologic union confirmed on computed tomography within 3 months postoperatively. Functional outcome scores improved, with QuickDASH scores improving from 31.9 and 36.4 preoperatively to 0 at long-term follow-up of 8.4 and 8.5 years. Both patients returned to pain-free, near-normal wrist function and activities, although heterotopic ossification along the pedicle was noted to limit wrist flexion and radial deviation. No clinical or radiographic evidence of distal femoral physeal arrest or growth disturbance was noted, with preserved knee function on follow-up.

CONCLUSION

This series demonstrates the feasibility of a physeal-sparing modified MFC osseous flap based on the transverse branch of the descending genicular artery for select skeletally immature patients with complex scaphoid nonunion. In these 2 cases, the technique avoided distal femoral physeal injury and was associated with union and good long-term wrist and knee function. However, heterotopic ossification, possible hardware-related impingement, and the need for secondary surgery in 1 patient highlight the importance of cautious patient selection and appropriate counseling.

LEVELS OF EVIDENCE: Level IV.