The original Burton-Pellegrini technique used to treat trapeziometacarpal joint osteoarthritis suggests the use of half of the flexor carpi radialis (FCR) width to reconstruct the ligament and perform the tendon interposition arthroplasty. In our study, unlike the original technique, we used the full thickness of the FCR and evaluated a sample of 100 thumbs (95 patients) preoperatively and postoperatively, with a mean follow-up of 36 months. According to the Eaton classification, 1 thumb was grade II, 81 were grade III, and 18 were grade IV. The mean patient age at the time of surgery was 62.4 years. The finger-tip pinch improved by 46.3%, the key pinch improved by 34.5%, the grip strength improved by 50.8%, and the Kapandji test improved by 7.4%. Pain measured with visual analog score improved by 78.8%. The self-administrated questionnaires DASH and PRWHE were completed postoperatively from 2006 to 2012, because the Italian version of PRWHE was not yet validated: the postoperative DASH and PRWHE were, respectively, 9.9 and 10.5. No complications such as metacarpal subluxation of the thumb, impingement, fracture of the first metacarpal base, or a decrease in the wrist function were found in our population after surgical treatment. Therefore, according to our series, this variation of the original Burton-Pellegini surgical technique provides pain relief, stability, and mobility of the thumb without any morbidity caused by the full harvest of the FCR tendon.