Treatment of duplicated thumb using a ligamentous/periosteal flap.

Since 1975, 22 duplicated thumbs in 21 children were treated by ablation of one of the digits, elevation of a ligament and periosteal flap from the proximal bone, reduction osteotomy to narrow the widened proximal bone, centralization of the retained thumb, and stabilization of the joint by reattaching the ligament and periosteal flap. In addition to improving the cosmetic appearance by centralizing the retained thumb on the narrowed proximal bone, good joint stability was provided. Three patients had subsequent joint arthrodesis because of laxity of the contralateral collateral ligament. The procedure is preferred to the reconstruction of a single digit by using component parts of both duplicated thumbs because the described procedure is technically simpler and does not potentially interfere with physeal growth or leave a nail matrix defect.