Purpose: To compare the outcomes of silicone proximal interphalangeal joint (PIPJ) arthroplasties to pyrolytic carbon implants in patients with osteoarthritis.
Methods: This study is a retrospective review of 41 arthroplasties in 22 patients with severe PIPJ osteoarthritis performed by a single surgeon. There were 13 patients and 22 joints in the silicone group with an average follow-up of 45 months. There were 9 patients and 19 joints in the pyrolytic carbon group with an average follow-up of 19 months. Clinical assessment included range of motion, grip strength, and deformity. Radiographs were evaluated for alignment, subsidence, and implant fracture. Patients filled out a subjective questionnaire with respect to pain, appearance of the finger, and satisfaction. Complications were recorded.
Results: In the silicone group, the average preoperative PIPJ range of motion (ROM) was 11 degrees /64 degrees (extension/flexion) and the average postoperative ROM was 13 degrees /62 degrees . In the pyrolytic carbon group, the average preoperative PIPJ ROM was 11 degrees /63 degrees and the average postoperative ROM was 13 degrees /66 degrees . Eleven of 20 joints in the silicone group and 4 of 19 joints in the pyrolytic carbon group had a coronal plane deformity as defined by angulation of the PIPJ > or =10 degrees . The average coronal plane deformity was 12 degrees in the silicone group and 2 degrees in the pyrolytic carbon group. The difference was statistically significant. In the silicone group, 3 of 22 joints required additional surgery. Two implants in one patient were removed and the PIPJ fused, and one implant was permanently removed for sepsis. In the pyrolytic carbon group, 8 of 19 joints squeaked, and there were 2 early postoperative dislocations and 2 implants with radiographic loosening. To date, there has been no revision surgery. Both groups had good pain relief. Patients were generally satisfied with the appearance of their joints in the pyrolytic carbon arm; however, satisfaction with appearance was variable in the silicone group. Nine of 13 patients in the silicone group and 6 of 7 patients in the pyrolytic carbon group would have the procedure again.
Conclusions: Both implants provide excellent pain relief and comparable postoperative ROM. Complications were implant specific. The results of this series show promise for the pyrolytic carbon PIPJ resurfacing arthroplasty but did not clearly demonstrate superiority compared with the silicone implant.