Vascularized thumb metacarpal periosteal pedicled flap for scaphoid nonunion: An anatomical study and pediatric case report.

PURPOSE: Through an anatomical review, the primary aim of this study was to delineate the dorsal thumb metacarpal (TM) periosteal branches of the radial artery (RA). In addition, we report here the clinical utility of a vascularized TM periosteal pedicled flap (VTMPF), supplied by the first dorsal metacarpal artery (FDMA), in a complex case of scaphoid nonunion.

METHODS: Ten latex-colored upper limbs from fresh human cadavers were used. Branches of the RA were dissected under 3x loupe magnification, noting the periosteal branches arising from the FDMA. The VTMPF was measured for both length (cm) and width (cm).

RESULTS: The FDMA provided a mean 12 periosteal branches (range 9 to 15), with a mean distance between branches of 0.5 cm (range 0.2-1.1), allowing for the design of a VTMPF which measured a mean 4 cm in length and 1.2 cm in width. We used a VTMPF to treat recalcitrant scaphoid nonunion, with a volar defect of 0.7 cm, in a 16-year-old boy. No bone graft was used. The patient experienced no postoperative complications. Successful consolidation was achieved three months after surgery, confirming the flap's survival. At 14-months of postoperative follow-up, the patient's VAS pain rating was 0 out of 100, and his DASH questionnaire score was 5. The patient had painless range that was 95% that of the contralateral limb. The patient's pinch and grip strengths were 6.5 kg and 28 kg, respectively (95% of unaffected side).

CONCLUSIONS: VTMPF may be considered a valuable and reliable surgical option for scaphoid nonunion in complex clinical scenarios.