Purpose: Scaphotrapezotrapezoidal (STT) pain is common but often asymptomatic. Medical treatment may be proposed if symptoms become bothersome. In case of failure, several surgical solutions may be proposed. The purpose of this work was to assess outcome in a series of eleven STT arthrodeses performed for isolated STT osteoarthritis.
Material and methods: Ten patients, three men and seven women (11 hands), mean age 63 years, developed STT osteoarthritis which was treated by arthrodesis. All patients experienced pain for daily life activities and had diminished wrist movement. According to the Crosby radiographic classification, three were one grade I, four grade II, and five grade II with carpal misalignmen t. One patient had chondrocalcinosis and six had tendinitis of the flexor carpi radialis. The anterior approach was used for three patients and the lateral approach for seven. Nine patients had an iliac graft to fill bony defects resulting from anterior wear. Pin fixation was used in six cases and staple fixation in five. An antebrachiopalmar cast was maintained for at least six weeks after surgery.
Results: At mean follow-up of 62 months, the pain score improved in all patients (p=0.05). There was no significant difference in motion, excepting decreased wrist extension (12°, p=0.03). Grasp and pinch force were not modified by STT arthrodesis. All patients were able to resume their former recreational and occupational activities. There was no worsening of the five cases with intracarpial deaxation. Four patients developed non-union (three pin fixations, one staple fixation), which was symptomatic in only two. These patients underwent successful revision using the same fixation technique. There were no complications.
Discussion: Like other series reported in the literature, our series of STT arthrodeses demonstrated effective pain relief. However, unlike former work, we were unable to obtain a significant reduction in the radial inclination force, or radio-carpal conflict. The other therapeutic option is resection of the distal pole of the scaphoid which provides more rapid clinical results but which leads to inevitable misalignment of the carpus.
Conclusion: We have decided to retain STT arthrodesis with iliac graft for patients with STT osteoarthritis, especially for young patients.