Clinical and Radiographic Outcomes Following Medial Collateral Ligament-Sparing Interposition Elbow Arthroplasty Using Acellular Dermal Allograft

Introduction Interposition arthroplasty is a joint-preserving option for younger patients with elbow osteoarthritis (OA) who are poor candidates for total elbow arthroplasty. However, optimal graft choice and surgical technique remain unclear. This study evaluates clinical and radiographic outcomes following interposition elbow arthroplasty using acellular dermal allograft with a medial collateral ligament (MCL)–sparing approach. Methods A retrospective review was performed of consecutive patients undergoing interposition elbow arthroplasty at a single academic institution from 2014 to 2025. Patients with ≥6 months' follow-up were included. Outcomes included Visual Analog Scale (VAS) pain, Disabilities of the Arm, Shoulder, and Hand (DASH) scores, range of motion, radiographic joint space, complications, and reoperations. Subgroup analyses were performed by diagnosis and revision status. Radiographic outcomes were analyzed using repeated measures analysis of variance. Results Eighteen patients (mean age, 54 years) were included, with mean follow-up of 40 (6-87) months for patient-reported outcomes. Significant improvements were observed in VAS pain (–3.0, P=.013) and DASH scores (–15.9, P=.036), with mean final values of 4.0 and 36.0 respectively. Range of motion generally improved from preoperative to postoperative (flexion 112-128 degrees, P=0.114; pronation 65-70 degrees, P=0.498; supination 62-65 degrees, P=0.507; extension was unchanged) but was not statistically significant. Complications and reoperation occurred in 0% of patients with primary surgery and in 50-60% of patients undergoing revision surgery. Radiocapitellar joint space increased postoperatively but decreased at final follow-up (P < .05), with no significant progression in OA severity. Conclusion Interposition elbow arthroplasty using acellular dermal allograft with an MCL-sparing approach yields improvements in pain and function that reach minimally clinically important difference. Patients undergoing revision or secondary surgery experienced very high rates of complication or reoperation, while those undergoing primary surgery did not. Despite partial loss of early radiographic gains, the procedure does not appear to accelerate degenerative changes, supporting its role as a joint-preserving option in younger patients.