Scaphoid implant resection arthroplasty. Long-term results.

A silicone scaphoid implant was developed in 1967 to help improve the results of simple resection arthroplasty in the treatment of arthritic changes associated with advanced scaphoid disease. Patients who had scaphoid implant surgery since 1967 were studied. Preoperative and postoperative roentgenograms, charts, surgical pathology, and clinical evaluations were reviewed. A total of 55 cases of scaphoid implant arthroplasty were evaluated. A classification system was developed based on progressive severity, and treatment recommendations were developed for each stage of disease progression. Cystic and degenerative changes in contiguous carpal bones were evaluated. No evidence of cystic change could be found in 37 wrists, minimal changes were found in 9, moderate changes in 5, and severe changes in 4. There were no implant infections or fractures. Implant rotation occurred in two cases. Functional use of the hand with decreased pain was observed. It is important to detect and treat carpal instability, which may be associated with scaphoid disease. Cystic formation can be minimized by avoiding oversized implants, treating the associated carpal instability, bone-grafting preexisting cysts, and avoiding Kirschner wire fixation. By following treatment protocols as established in the classification system, the scaphoid implant can be successfully used in the management of scaphoid pathology.