Soft tissue interposition arthroplasty for scaphoid nonunion.

Twenty-six patients with scaphoid nonunion were reexamined 22 to 39 years after Bentzon's soft tissue interposition arthroplasty was performed. All but one were satisfied, although three still had moderate pain. Mobility of the wrist was reduced by 20% to 25% and grip strength by 8%. The nonunion remained open and unstable in 16 of 25 radiologically reexamined cases. Carpal collapse, which had increased over time, was found in 15 cases, nine of which presented an unstable nonunion. Osteoarthritis had developed in five of 15 wrists with carpal collapse and in two of 10 without it. No significant osteoarthritis was found in any case earlier than 27 years after the operation. Thus, the risk of disability that is due to late degenerative changes of the wrist is small, even in the presence of carpal collapse.