gms | German Medical Science

Objectives/Interrogation: There have been many reports on the usefulness of three-dimensional preoperative planning (3D planning) using computed tomography (CT) for total knee and hip arthroplasties. However, few reports have described CT-based 3D planning for prosthetic arthroplasty of the upper limbs. We report a case of total wrist arthroplasty (TWA) using CT-based 3D planning.

Methods: A 65-year-old female presented to our hospital with weakness of the extensors of the left middle and ring fingers, which had gradually progressed over 2 months. She also had suffered from left wrist pain for 2 years. Having been diagnosed previously with rheumatoid arthritis and systemic sclerosis, she had been treated with methotrexate and tocilizumab since she was 40 years old. On physical examination, her left wrist was swollen, and the range of motion of her wrist joint was restricted: -10 degrees in extension to 40 degrees in flexion. Plain radiography revealed advanced bone destruction of the wrist joint and volar dislocation of the carpal bones, indicating arthritis mutilans. We planned a total wrist arthroplasty and extensor tendon reconstruction. After a 3D digital model of the wrist was reconstructed using CT and software, the computer-aided design models of the implant were superimposed on the wrist; the appropriate size and position of the implant were determined. During surgery, the planned parameters were measured with a slide gauge to reproduce the 3D-planned position of the implant. The size of the implant used at surgery was the same as in 3D planning, and the location of the implant was virtually the same as in 3D planning. Nine months after surgery, the extension and flexion of her wrist improved to 15 degrees and 35 degrees, respectively. Postoperative complications were not observed.

Results and Conclusions: It is difficult to place an implant in the proper position during TWA since the procedure is indicated for the treatment of severe wrist deformity due to RA with advanced bone destruction and bone weakness. The size and position of the implant can be appropriately predicted by 3D planning. Our method may contribute to a reduced incidence of complications and improved long-term outcomes after TWA.