Treatment of Eaton stage I trapeziometacarpal disease with thumb metacarpal extension osteotomy.

The current benchmark for the treatment of Eaton stage I disease of the trapeziometacarpal (TMC) joint includes palmar oblique ligament reconstruction and reflects its primary role in providing stability during lateral pinch. This study prospectively evaluates the efficacy of an alternative extra-articular approach using a 30 degrees extension osteotomy of the thumb metacarpal to redistribute trapeziometacarpal contact area and load, obviating the need for ligament reconstruction. Preoperative and postoperative subjective and objective data are reported for 12 patients enrolled in the study between 1995 and 1998. Trapeziometacarpal arthrotomy allowed accurate intra-articular assessment and verified palmar oblique ligament incompetence in each case. The average follow-up period was 2.1 years (range, 6-46 months). All osteotomies healed at an average of 7 weeks. Eleven patients were satisfied with outcome. Grip and pinch strength increased an average of 8.5 and 3.0 kg, respectively. Thumb metacarpal extension osteotomy is an effective biomechanical alternative to ligament reconstruction in the treatment of Eaton stage I disease of the trapeziometacarpal joint.