Abstract
Dear Sir,
Scaphotrapeziotrapezoid (STT) arthrodesis is mainly used for treating STT arthritis. Trapeziectomy, fibrous arthoplasty and prosthetic arthroplasty are alternative surgical options. The nonunion rate of STT arthrodesis with free bone grafting has been estimated to be 0–26% and additional surgery is necessary in difficult cases (Ishida and Tsai, 1993). We describe a new vascularized bone grafting (VBG) technique and its outcome for treating STT arthritis in three patients.
The average age of the patients at the time of the operation was 67 years (range 55–77 years). All patients were female and right-handed and the dominant hand was affected in all cases. We used the method of Zaidemberg et al. (1991) as the VBG technique. The STT joint surface was refreshed and a bone cavity was created for the VBG. A VBG graft attached to the 1,2 inter-compartmental supraretinacular artery (1,2-ICSRA) was harvested 20–22 mm away from the radiocarpal joint surface. Cancellous bone chips were also harvested from the same cavity in the distal radius and grafted into the small space around the VBG. The bone graft was secured with Kirschner wires and 3–4 weeks of additional plaster immobilization was used.
We assessed pain on a scale of 1–4 (1, no pain; 2, slight or occasional pain; 3, moderate pain; 4, severe pain) and a satisfaction score of 1–3 (1, complete satisfaction; 2, partial satisfaction; 3, dissatisfaction). We determined the range of motion (ROM) in flexion and extension of the wrist and grip power. The average pain score improved from 3.3 to 1.0, and the average satisfaction score improved from 2.6 to 1.0. All patients returned to preoperative daily activities. The average preoperative ROM was 93° (range 90–100°), whereas the average postoperative ROM was 72° (range 65–75°). The preoperative grip strength was 12 kg in one case. We were unable to measure the grip in the other two cases because of intense pain. The average postoperative grip strength was 13 kg (range 8–16 kg). Radiological bone union was achieved at 10 weeks postoperatively on average (range 8–12 weeks) and the Kirschner wires were removed after union. There were no significant postoperative complications. The mean follow-up period was 43 months (range 38–50 months). Typical pre- and postoperative radiographs are shown in Figure 1.
(A) Preoperative radiograph. (B) Postoperative radiograph 4 years after surgery in the same patient.
We used cancellous bone graft and VBG when carrying out STT arthrodesis. Sunagawa et al. (2000) reported that VBG improved the rate of union in a canine model of scaphoid nonunion with avascular necrosis. Revascularization may occur in both the free bone grafts and the surrounding bone of the STT joint with the use of a VBG. Although we found that this procedure was effective in STT arthrodesis, more clinical cases with long-term follow-up are required to establish the effectiveness and complications of STT arthrodesis with VBG.
Footnotes
Conflict of interests
None declared.