Trapeziectomy for basal thumb osteoarthritis does not increase the risk of developing wrist osteoarthritis in the long term

BACKGROUND: Symptomatic osteoarthritis of the basal joint of the thumb (trapeziometacarpal joint) is a common disabling condition mainly affecting women. It is frequently treated with complete removal of the trapezium with or without soft-tissue interposition. There is limited evidence about whether removal of the trapezium affects stability of the wrist joint and increases the risk of developing wrist osteoarthritis. The aim of this study was to evaluate the long-term prevalence of OA in wrists with previous trapeziectomy compared to wrists with intact trapezium. METHODS: Patients treated with surgery for trapeziometacarpal osteoarthritis at one orthopedic department were invited 10–29 (mean 17) years postoperatively for bilateral radiographic examination. We included radiographs from 114 hands with trapeziectomy and 46 hands with intact trapezium; 38 patients had unilateral trapeziectomy and intact contralateral trapezium. The radiographs were blinded so that the intact trapezium or the trapezial space after trapeziectomy was not visible. The radiographs were then evaluated for radiocarpal/midcarpal osteoarthritis independently by two assessors using three different osteoarthritis grading systems, including the Kellgren–Lawrence classification. The patients rated their satisfaction with the function of each of their hands on a visual analog scale (VAS) from 0 to 100 (higher score better). RESULTS: The prevalence of osteoarthritis ranged from 20 to 26%, mostly mild (Kellgren–Lawrence grade 1). The prevalence of osteoarthritis did not differ between wrists with previous trapeziectomy and those with intact trapezium, both in the whole cohort and in the subgroup of patients with unilateral trapeziectomy and intact contralateral trapezium. There was no significant difference in hand function VAS scores between hands with previous trapeziectomy and hands with intact trapezium in the whole cohort or in the subgroup. CONCLUSIONS: Removal of the trapezium as treatment for basal thumb osteoarthritis does not increase the risk of developing wrist osteoarthritis in the long term.