Reexploring the Anatomy of the Distal Humerus for its Role in Providing Vascularized Bone

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

BACKGROUND

Free 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.

METHODS

Nine 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).

RESULTS

All 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 × 0.5 cm × 0.5 cm to 2.0 cm × 1.0 cm × 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° (range 45°-70°), 56.1° (range 40°-80°), 10.6° (range 5°-20°), and 22.2° (range 15°-35°), 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.

CONCLUSION

The 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.

[Repair of resurfacing soft tissue defect of hand with radial collateral artery polyfoliate perforator flap]

Objective

To explore the feasibility and effectiveness of radial collateral artery polyfoliate perforator flap in repair of resurfacing soft tissue defect of hand.

Methods

Between September 2017 and September 2018, the radial collateral artery polyfoliate perforator flaps were transplanted to repair 5 cases of two adjacent wounds of hand and wide or irregular wounds. All patients were male, aged from 27 to 52 years, with an average of 42.5 years. The time from injury to admission was 4 hours to 3 weeks, with an average of 7.3 days. Causes of injury included traffic accident in 2 cases, crushing injury in 2 cases, and paint injection injury in 1 case. The wounds were located at the dorsum of hand in 3 cases, the dorsum of finger in 1 case, and the thumb and thumb web in 1 case. The area of wound ranged from 8 cm×6 cm to 10 cm×8 cm. The area of skin flap ranged from 6.0 cm×3.0 cm to 11.0 cm×4.5 cm, all of which carried the posterior cutaneous nerve of the arm, and the donor site was closed directly.

Results

All flaps survived and healed by first intention. All patients were followed up 3-11 months (mean, 6.5 months). The patients were satisfied with the appearance of hands. The flaps were not bulky, and the color and texture were similar to the hand. There was only linear scar in the donor site, no radial nerve injury occurred, and elbow joint function was not affected. One patient underwent finger-splitting and skin flap thinning at 6 months after operation.

Conclusion

The radial collateral artery polyfoliate perforator flap is a good method for repairing two adjacent wounds and wide or irregular wounds of hand.