Surface replacement arthroplasty of the proximal interphalangeal joint using the SR PIP implant: long-term results.

PURPOSE: To evaluate the long-term results of proximal interphalangeal (PIP) joint surface replacement arthroplasty for arthritis using the SR PIP implant (Small Bone Innovations, New York, NY). METHODS: This is a long-term retrospective analysis of results in 39 of 43 joints first reported in 2008. Subjective results were based upon a mailed questionnaire. Active range of motion was measured by a certified hand therapist, and x-rays were obtained to analyze changes occurring since the first study. RESULTS: The average follow-up time was 9.3 years. The average active PIP joint arc of motion in the present cohort of patients went from 64° at the first report (2008) to 56° at this time. Radiographic comparisons revealed no major changes since the first study. Ten of 11 revisions were done for pain due to loosening and were performed at an average of 20 months after the primary procedure. No further revisions were necessary in the interim. Overall, subjective measures of satisfaction and symptomatic and functional improvement remained unchanged. CONCLUSIONS: Surface replacement arthroplasty using the SR PIP implant continues to be an option for patients with osteoarthritis of the PIP joint. Long-term subjective and objective outcomes are comparable to those reported using other implants. This and other studies suggest that this procedure is not appropriate for most rheumatoid joints. In the interim between studies, we saw a reduction in the average PIP joint arc of motion, although this change did not reach statistical significance. Our original revision incidence of 26% has not changed. Subjective evaluation and radiologic findings did not change between studies. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Surface replacement arthroplasty of the proximal interphalangeal joint using the PIP-SRA implant: results, complications, and revisions.

PURPOSE: To evaluate the subjective and objective results of surface replacement arthroplasty (SRA) for arthritis of the proximal interphalangeal (PIP) joint using the PIP-SRA implant. Emphasis is placed on causes of complications, failures, and techniques used for revision. METHODS: This is a retrospective review of 43 surface replacement PIP joint arthroplasties performed in 25 patients using the PIP-SRA implant. Subjective results were obtained through a mailed questionnaire. Pre- and postoperative ranges of motion were obtained for PIP joints and DIP joints. X-rays were evaluated for signs of subsidence, periprosthetic radiolucency, loosening, or stress-shielding. Joints requiring revision were separately analyzed. RESULTS: The average follow-up time was 37 months (range, 12 to 72 months). The average active PIP joint arc of motion went from 57 degrees before surgery to 58 degrees after surgery, excluding 2 joints that were salvaged with arthrodesis. The average active DIP joint arc of motion went from 36 degrees before surgery to 24 degrees after surgery, excluding arthrodeses. Satisfaction rating revealed 26 very satisfactory (60%), 12 fairly satisfactory (28%), and 5 not satisfactory (12%). Thirty-three patients rated their joint pain better, 3 joints were unchanged, and 7 were worse. Eleven (26%) arthroplasties failed, requiring major revision (arthrodesis or replacement of 1 or both components) for pain. Ten of 11 revisions were due to loosening associated with the lack of cement. Revision procedures produced satisfactory results in 8 of 11 joints. CONCLUSIONS: Surface replacement arthroplasty of the PIP joint holds promise for the future. It offers motion and stability for the index finger unattainable with silicone arthroplasty. Our results do not differ notably from those of other series using this implant, except that failures due to loosening in our study were almost exclusively associated with the lack of cement. Therefore, we recommend using cement with the PIP-SRA implant in every case until superior long-term results can be demonstrated using uncemented components. Proximal interphalangeal joint arthroplasty is an exacting procedure no matter what technique or implant is used, and no one technique has yet been proven superior to all others. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.