Scaphoid-trapezium-trapezoid fusion in the treatment of chronic scapholunate instability

Abstract

Limited intercarpal arthrodesis for chronic scapholunate instability has been the subject of several recent publications. We have followed nine patients, who had scapho-trapezio-trapezoidal (S-T-T) fusion for scapholunate instability. All nine patients were re-examined recently after an average follow-up period of 19 months (range, 12 to 25 months). Six of the nine patients believed that their symptoms were significantly improved. The postoperative range of wrist motion (ROM) was decreased in all directions of motion. The pinch strength averaged 86% on the treated side and the grip strength averaged 74% of the unoperated side. Review of follow-up x-ray films showed radiographic evidence of union in eight of nine patients. We conclude that, with careful patient selection and close attention to operative detail, S-T-T fusion can be an effective treatment for scapholunate instability. However, the results are not uniformly predictable, and neither range of motion nor strength is normal after the procedure.