Disabling Arthritis at the Base of the Thumb

Arthritic involvement of the joints at the base of the thumb can seriously interfere with normal function of the hand. This disability may result from osteoarthritis, traumatic arthritis, or rheumatoid arthritis. The severity of the symptoms and deformity depend on the severity of the destructive changes which occur at the basal thumb joints and the resulting imbalance of forces on the distal thumb joints. The swan-neck deformity seen in rheumatoid thumbs and in severe osteoarthritic thumbs is caused by arthritic changes of the basal joints. [See figure in the PDF file]. A study of the roentgenograms of the patients selected for reconstructive surgery of the thumb demonstrated that the arthritic changes most frequently occur at the trapeziometacarpal joint, but that the trapezioscaphoid, trapeziotrapezoid, and the trapezio-second metacarpal joints are also involved in a significant number of cases. The trapezium was at the center of the arthritic process in all cases of osteoarthritis and of traumatic arthritis. Rheumatoid patients may have a similar localized involvement of the basal thumb joints. They also may have severe absorptive changes of the trapezium and base of the metacarpal which produces a result not unlike a resection arthroplasty. If the joint is reasonably stable, mobile and pain-free, no surgery is indicated. A new method of trapezium resection and implant arthroplasty for the treatment of disabilities at the base of the thumb is described. Total resection of the affected trapezium and replacement with a heat-molded, intramedullary-stemmed silicone rubber implant has been used successfully in my clinic for the last five and one-half years. It has restored a stable, mobile, pain-free and powerful thumb. With a mobile joint at the base of the thumb, a severe collapse deformity can be treated by fusion of the distal joints, if need be, without producing a rigid thumb. The indications and surgical techniques are discussed as well as the treatment of the associated collapse deformities of the thumb and the technical pitfalls that must be avoided. The results obtained in forty-six thumbs operated on during the past five and one-half years are presented. The trapezium resection implant arthroplasty is a reliable method of treatment for disabling arthritis at the base of the thumb if certain simple points of technique are followed.