Comparison of tendon suspension-interposition and silicon spacers in the treatment of degenerative osteoarthritis of the base of the thumb.

In a retrospective study, 75 patients with tendon suspension-interposition arthroplasty were compared with 27 patients with prosthetic replacement of the trapezium for CMC I osteoarthritis. A significant decrease in pain and an increase in subjective strength was observed in both groups. The extent of change was not significantly different between the two groups. Although there was radiographically less proximalisation of the thumb in the patient group with silastic interposition, objective strength and range of motion was not significantly different between the two groups. Since the results of trapeziectomy for the treatment of degenerative osteoarthritis of the base of thumb with or without silicone interposition are comparable, the use of silastic implants, with their inherent complications, no longer seems to be justified. There might be a place for the condylar type of implants in low-demand rheumatoid patients, in whom as much bone stock as possible should be preserved.