Vascularized medial femoral trochlea osteocartilaginous flap reconstruction of proximal pole scaphoid nonunions.

Purpose: The descending geniculate artery's branching pattern includes periosteal vessels supplying the cartilage-bearing trochlea of the medial patellofemoral joint. Previous cadaveric studies described anatomic similarities between the greater curvature of the proximal scaphoid and the convex surface of the medial femoral trochlea (MFT). We describe the technique and report our first 16 consecutive cases of vascularized osteocartilaginous arthroplasty for chronic scaphoid proximal pole nonunions using the MFT, with a minimum of 6 months of follow-up.

Methods: Chart reviews of 16 consecutive cases of osteocartilaginous MFT flap transfers for scaphoid reconstruction were performed at 2 institutions. Follow-up data were recorded at a minimum of 6 months, with an average of 14 months (range, 6-72 mo). Patient age and sex, duration of nonunion, number of previous surgical procedures, surgical technique, achievement of osseous union, preoperative and postoperative scapholunate angles, preoperative and postoperative range of motion, and pain relief were recorded.

Results: Computed tomography imaging confirmed healing in 15 of 16 reconstructed scaphoids. Mean patient age was 30 years (range, 18-47 y). The average number of previous surgical procedures was 1 (range, 0-3). All patients experienced some wrist pain improvement (12/16 complete relief, 4/16 incomplete relief). Wrist range of motion at follow-up averaged 46° extension (range, 28° to 80°) and 44° flexion (range, 10° to 80°), which was similar to preoperative measurements (average 46° extension and 43° flexion). Scapholunate relationship remained unchanged with average scapholunate angles of 52° before surgery and 49° after surgery.

Conclusions: Osteochondral vascularized MFT flaps provide a reliable means of achieving resolution of difficult proximal pole scaphoid nonunions. These flaps allow resection of the proximal portion of the unhealed scaphoid and reconstruction with an anatomically analogous convex segment of cartilage-bearing bone. This technique provides the advantages of vascularized bone and ease of fixation. Early follow-up demonstrates a high rate of union with acceptable motion and pain relief.

Clinical Relevance: Early follow-up suggests that the vascularized MFT osteocartilaginous flap is a valuable tool for treating challenging proximal pole scaphoid nonunions.