Long-term assessment of Swanson implant arthroplasty in the proximal interphalangeal joint of the hand.

PURPOSE: The purpose of this study was to evaluate the clinical results of Swanson silicone implant arthroplasty of the proximal interphalangeal (PIP) joint, specifically evaluating clinical results with long-term assessment.

METHODS: A retrospective review of 70 silicone implants of the PIP joint in 48 patients was performed with an average follow-up period of 6.5 years (range, 3-20 y). Clinical assessment included motion, stability, and alignment. Radiographic assessment included implant fracture, deformity, and cystic bone resorption. The pathology consisted of degenerative joint disease in 14, posttraumatic arthritis (TA) in 11, rheumatoid arthritis (RA) in 13, and idiopathic arthritis (IA) associated with collagen disease in 12 patients. Swan neck and boutonniere deformities were assessed separately. Statistical analysis of preoperative risk factors was compared with the postoperative assessment of pain, motion, and function (return to work).

RESULTS: There was no significant change in the active range of motion (ROM) before and after PIP arthroplasty (26 degrees vs 30 degrees ). Correction of swan neck and boutonniere deformities was difficult, usually leading to poor results. There was improvement in maximum active extension before surgery lacking 32 degrees to after surgery lacking 18 degrees . From a statistical standpoint rheumatoid joint involvement with PIP arthroplasty had poorer results than degenerative or posttraumatic arthritis with respect to pain relief and ROM. Pain relief was present in 70% of replaced PIP joints with residual pain and loss of strength in 30%. Radiographic analysis showed abnormal bone formation (cystic changes) in 45%. There were 11 implant fractures and 9 joints that required revision surgery.

CONCLUSIONS: Silicone replacement of the PIP joint is effective in providing relief of pain from arthritis but does not provide improvement in motion or correction of deformity. It provided a poorer outcome in rheumatoid disease in comparison with degenerative, posttraumatic, or idiopathic arthritis.