Ligament reconstruction/tendon interposition arthroplasty (LRTIA) is a common procedure for basal joint osteoarthritis of the thumb. We evaluated 31 operations in 30 patients, 28 females, 2 males with a mean age of 57 years. The mean follow-up was 24 months (range 8 to 46 months). Pain reduction was 75% on average, with good preservation of motion and of first web space. Twenty-six patients were satisfied or very satisfied; five were not. The grip strength and key-pinch strength increased post-operatively, albeit not significantly.