Abstract
Background
The trapeziometacorpal joint (TMJ) of the thumb is a common site of primary osteoarthritis. Pain, crepitis and instability secondary to subluxation are common symptoms associated with TMJ arthritis. Conservative therapy help to control symptoms however with time, many patients progress with pain, deformity and functional limitation. The goals of operative intervention are to restore stability and strength, decrease pain and to provide a functional range of motion. Francobal-prosthesis may fulfil these criterions.
Technique
We implanted the prosthesis through a dorso-radial straight longitudinal or slightly curved skin incision. A dorsal capsulotomy is performed and at this step adduction deformity should be addressed. An osteotomy of the proximal surface of the first metacarpal is made perpendicular to the long axis of the medullary cavity followed by reaming of the medullary cavity and then a trial fit. This is followed by preparation of the trapezium including removing any osteophytes, drilling of a cavity. Dental burs may be used at this step to deepen the cavity. The process of cementation started by cementation of the cup with its opening neutral to the joint surface, and if there is any muscle tension, bone is removed from the metacarpal before the metacarpal component is cemented. Reduction is achieved by snapping. The capsule and wound are closed and the thumb is immobilised in an adduction splint for ten days.
Results
Results showed marked improvement of pain in many patients with high rate of satisfaction. No restriction of movement or instability was observed. In some cases, loosening of the shaft was noticed. However, this does not affect the overall function.
Discussion
De La Caffini`re-prosthesis presents one of the operative options in the management of trapeziometacorpal joint (TMJ). Arthritis, however, this operation is recommended only in selective cases where skaphoid-trapezium-trapezoid (STT) joints are not involved.
