Free vascularized bone graft from the lateral epicondylar region of the humerus for treatment of scaphoid nonunion

BackgroundFree vascularized bone grafting (FVBG) has become one of the essential methods for treating scaphoid nonunion complicated by avascular necrosis. However, commonly used bone graft, including the medial femoral condyle bone graft and iliac crest bone graft, still present challenges such as a high rate of donor site complications and variations of vascular pedicle. In this study, we have introduced a novel bone graft-the lateral humeral condyle bone graft with the posterior branch of the radial collateral artery (PBRCA) as the vascular pedicle-as an alternative option, with the aim of overcoming some of the limitations of previously described FVBG procedures.MethodsNine patients who had a nonunion of the scaphoid that had been present for an average of 16.8 months (range 9-35 months) were managed with use of a free vascularized bone graft obtained from the lateral humeral epicondylar region. Avascularity of the scaphoid, as assessed on preoperative magnetic resonance imaging and intraoperative bone marrow puncture test. Postoperatively, regular X-ray and CT scans examinations were conducted to assess the progress of fracture healing. Active motion of the wrist, and grip strength recovery were measured periodically. Wrist pain was graded using the Visual Analogue Scale (VAS), while wrist joint functionality was evaluated using the Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) questionnaire and the Patient-Rated Wrist Evaluation (PRWE) scale. The elbow functional outcome was evaluated by the Mayo Elbow Performance Score (MEPS).ResultsAll of nine lateral humeral epicondylar bone grafts were successfully harvested. The blood supply of the graft during surgery was excellent in six cases and good in three cases. The size of the bone grafts ranges from 1.0 cm x 0.5 cm x 0.5 cm to 2.0 cm x 1.0 cm x 0.5 cm. The average vascular pedicle length was 3.4 cm (range 2.0-6.0 cm). There were no early complications in either the donor or recipient areas after surgery. Union was successfully achieved in all nine patients, with an average time to union of 14.3 weeks (range 11-20 weeks) after surgery. The average follow-up period was 31.2 months (range 26-40 months). At the final follow-up, the average palmar flexion, dorsal extension, radial deviation, and ulnar deviation angles of the injured wrist joint were 56.1 degrees (range 45 degrees-70 degrees), 56.1 degrees (range 40 degrees-80 degrees), 10.6 degrees (range 5 degrees-20 degrees), and 22.2 degrees (range 15 degrees-35 degrees), respectively, which reached 79.0%, 82.1%, 59.4%, and 72.8% of the average activity of the contralateral normal side. The average grip strength of the injured side was 35.2 kg (range 22-51 kg), which was equivalent to 81.3% of the average grip strength of the contralateral side. The average VAS score for wrist joint pain was 1.0 point (range 0-2 points); the Quick-DASH score was 9.2 points (range 6-18 points); and the PRWE score was 13.1 points (range 9-16 points), the Mayo Elbow Performance Index was 100 points (range 100-100 points). One patient reported a feeling of friction during movement but no pain. One patient reported numbness in the donor site. One patient complained of pain when applying force to the scar in the donor area. During the follow-up period, these complications showed improvement without any treatment.ConclusionThe FVBG technique has been considered an effective method for treating scaphoid nonunion with avascular necrosis. Compared to traditional FVBG, the lateral humeral epicondylar bone graft exhibits a higher union rate, fewer complications, and easier accessibility, making it a favorable choice.