Long-Term Outcome of Arthroscopic Resection Arthroplasty With or Without Interposition for Thumb Basal Joint Arthritis.

PURPOSE To report results on 144 cases following arthroscopic resection arthroplasty (ARA) with or without interposition for basal joint arthritis. METHODS Cases undergoing ARA for thumb carpometacarpal osteoarthritis between 2004 and 2011 were prospectively enrolled (n = 178). Data were collected before surgery and after surgery at 1, 3, 6, and 12 months and annually thereafter. Patients were excluded for less than 1-year follow-up or concomitant procedures that interfered with evaluation of the variable of interest (interposition). Human acellular dermal matrix (GRAFTJACKET) was the most commonly used interposition. Outcomes on 19 cases of interposition using collagen bioimplant (OrthADAPT) and porous polyurethaneurea (Artelon) scaffolds were also reported. Comparative analyses were performed on 52 patients with GRAFTJACKET interposition and on 73 without. Mean follow-up was 7.4 and 5.6 years with and without interposition, respectively. Descriptive statistics were evaluated on all baseline variables. Raw change scores of grip, pinch, and pain outcomes were evaluated. Confounding variables at a significance level of P less than .05 were adjusted for in linear mixed models, and an analysis of covariance was employed through an unstructured type of variance-covariance matrix. RESULTS Change scores from baseline to 1 year for the interposition group for pain (numerical rating scale, 0-10), pinch, and grip was -5.8, 3.3, and 7, respectively, and -5.1, 2.1, and 9 for the noninterposition group. Postoperative mean satisfaction was 4.7 and 4.4 for the with- and without-interposition groups, respectively. There were 4 failures with and 2 without interposition. Artelon and OrthADAPT did poorly with unacceptably high failure rates. CONCLUSIONS This study suggested that interposition is not necessary following ARA for thumb basal joint arthritis. Because arthroscopic interposition of material contributes to health care costs in terms of patient and facility costs without clear benefit to the patient, routine use of expensive interposition products should be abandoned or carefully evaluated with a prospective randomized controlled trial. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.