This randomized prospective study compared the treatment of trapeziometacarpal joint osteoarthritis with a) trapeziectomy with no ligament reconstruction, no soft tissue interposition and no temporary Kirschner wire stabilization (Group T); b) trapeziectomy with flexor carpi radialis ligament reconstruction and interposition and temporary K-wire stabilization (Group T+LRTI). We followed 99 patients with 114 thumbs (59 T and 55 T+LRTI) for a mean of 6.2 (range, 4.2-8.1) years. There were no significant differences between the two treatments in any subjective or objective outcome measure at 6 year follow-up. Eighty-two percent of the thumbs were painless or only ached after use. The DASH (Group T mean, 31; 95% CI, 26-42: Group T+LRTI mean 30; 95% CI, 22-35) and Patient Evaluation Measure (Group T mean, 35; 95% CI, 29-41: Group T+LRTI mean 34; 95% CI, 27-39) scores were significantly better than preoperatively. Thumb key pinch strength did not differ significantly between the two treatment groups (Group T mean 3.7 kg: 95% CI, 3.3-4.2: Group T+LRTI mean 4.1 kg, 95% CI, 3.7-4.7) and was not significantly different from the preoperative key pinch strength. This study does not provide evidence to support the use of LRTI and temporary K-wire stabilization after trapeziectomy.