Basal joint arthroplasty using an allograft tendon interposition versus nointerposition: A radiographic, vascular, and histologic study

To assess the role of a tendon spacer that fills the trapezial void, the tr apeziums were excised and anterior oblique ligaments were reconstructed in 25 monkeys. In addition to the ligament reconstruction, 20 of the monkeys h ad the trapezial void filled with a tendon allograft. The trapezial space w as investigated at 0, 3, 6, 15, and 40 weeks using routine histologic stain ing, arterial perfusion (Spalteholz), and standardized radiographs. There w as a statistically greater decline in trapezial height in the animals witho ut tendon interposition allografts. The tendon grafts became progressively neovascularized and populated with fibroblasts. fly 40 weeks, the allograft was no longer a folded tendon but a homogeneous mass of collagen, fibrobla sts, and capillaries. The specimens without an interpositional tendon graft had loose fibroadipose tissue filling the carpal void. Polarized light mic roscopy showed fibers crossing the subchondral bone and moving into the adj acent fibrous spacer in the specimens implanted with a tendon graft. The re sults indicate that filling the trapezial void with an interposition tendon spacer may aid in maintaining normal wrist anatomy. (J Hand Surg 2000;25A: 447-457. Copyright (C) 2000 by the American Society for Surgery of the Hand .).