Total arthroplasty of the thumb trapeziometacarpal joint.

Considering the large number of procedures designed for the thumb trapeziometacarpal (TMC) joint, it is evident that none are completely satisfactory. Total arthroplasty attempts to improve the results of resection or space-occupying arthroplasties which, while providing good pain relief, have offered little thumb stability, strength, or normal motion. Conditions of surrounding joints indicate that this disease process is not always a straightforward clinical presentation and that a variety of surgical options are needed. When joint disease is limited to the TMC joint, bone stock is good and there is no excessive heterotopic bone. A total arthroplasty can be considered in selected patients. Careful analysis of comparative series between silicone spacers and tendon spacers for trapezium resection arthroplasty demonstrates that both pinch strength and motion are somewhat less than with total trapezial arthroplasty. Key-type pinch rarely was over 50% of the normal and averaged less than 5 kg for both interposition and silicone arthroplasty. Continued problems with implant subluxation, silicone reactive synovitis, and other complications suggest that these resections (replacement) of the trapezium are not error-free and sacrifice thumb stability. With all types of thumb reconstruction, high precision technique is required. With improved biomaterials, thumb biomechanics, and better fixation techniques, more physiologic implant arthroplasties can be anticipated to improve the current designs of total joint arthroplasties.