Serial Changes in Clinical Outcomes After Arthroscopic Osteocapsular Arthroplasty for Primary Elbow Osteoarthritis: A Medium-term Follow-up Study

BACKGROUND: Arthroscopic osteocapsular arthroplasty (OCA) shows promising short-term outcomes for primary elbow osteoarthritis (OA). However, serial changes in clinical outcomes for medium-term follow-up are not well known. PURPOSE: To evaluate clinical outcomes after arthroscopic OCA in primary elbow OA from preoperative to short- and medium-term follow-up and to analyze the correlation between the time from short- to medium-term follow-up and the changes in clinical outcomes between the periods. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients with primary elbow OA who were treated with arthroscopic OCA between January 2010 and April 2020 were evaluated. Elbow range of motion (ROM), visual analog scale (VAS) for pain, and Mayo Elbow Performance Score (MEPS) were assessed preoperatively and at short-term (3-12 months) and medium-term (≥2 years) follow-up. The correlation between the time from short- to medium-term follow-up and the changes in clinical outcomes was analyzed using the Pearson correlation coefficient. RESULTS: Included were 56 patients who underwent short-term follow-up (mean [range], 5.9 [3-12] months) and medium-term follow-up (62.2 [24-129] months) after arthroscopic OCA. When compared with preoperative values, significant improvements were seen at short-term follow-up: ROM (from 89.4° to 111.7°; P < .001), VAS for pain (from 4.9 to 2.0; P < .001), and MEPS (from 62.3 to 83.7; P < .001). From short- to medium-term follow-up, ROM decreased (from 111.7° to 105.4°; P = .001) while VAS for pain (from 2.0 to 1.4; P = .031) and MEPS (from 83.7 to 87.8; P = .016) improved. All outcomes improved significantly at medium-term follow-up as compared with preoperative values (P < .001 for all). The time between short- and medium-term follow-up had a significant positive correlation with decreased ROM (r = 0.290; P = .030) and a significant negative correlation with improvement in MEPS (r = –0.274; P = .041). CONCLUSION: Serial assessment of patients with primary elbow OA who underwent arthroscopic OCA showed that the clinical outcomes improved from preoperative assessment to short- and medium-term follow-up, although ROM decreased between short- and medium-term follow-up. VAS for pain and MEPS showed continued improvement until medium-term follow-up.