Titanium scaphoid implant for scaphoid nonunion

Abstract

A titanium scaphoid implant was developed in 1985 as an alternative to the silicone model. Surgical indications included aseptic necrosis with arthritic changes of the scaphoid, failures from previous surgery including bone grafting for fracture nonunion, and arthritic involvement of the scaphoid with associated carpal instability, particularly the scapholunate advanced collapse (SLAC) wrist pattern. An additional indication was revision surgery following a previous scaphoid silicone implant with swelling and pain in the presence of cystic or progressive degenerative bony changes. Between 1985 and 1990, Swanson performed 54 titanium scaphoid arthroplasties. The results were analyzed on 28 patients (29 cases) with 24 months follow-up or greater (range 24 to 55 months). Preoperative and postoperative roentgenograms were reviewed to assess changes in carpal height and radiolunate angle. Cystic changes in contiguous carpal bones, bone tolerance, and maintenance of implant position were also evaluated. Postoperatively, there was improved functional use of the hand with marked decreased pain. The carpal height was well maintained and the congruity of the contiguous carpal bones were well maintained. Important steps of the procedure include curettage and cancellous bone grafting of preexisting subchondral bony cysts and correction of associated carpal instability and degenerative changes with selective intercarpal functions