Radiologically severe osteoarthritis is related to worse clinical outcomes after arthroscopic osteocapsular arthroplasty in primary elbow osteoarthritis at medium-term follow-up: a retrospective cohort study

Hypothesis: This study aimed to compare the clinical outcomes after arthroscopic osteocapsular arthroplasty (OCA) at medium-term follow-up according to the radiologic severity of primary elbow osteoarthritis (OA) and assess serial changes in clinical outcomes in each group. Methods: Patients treated from January 2010 to April 2019 with arthroscopic OCA for primary elbow OA with a minimum of 3 years' follow-up were retrospectively assessed regarding range of motion (ROM), visual analog scale (VAS) pain score, and Mayo Elbow Per-formance Score (MEPS) preoperatively, at short-term follow-up (3-12 months postoperatively), and at medium-term follow-up (>= 3 years after surgery). Preoperative computed tomography was performed to evaluate the radiologic severity of OA using the Kwak clas-sification. Clinical outcomes were compared according to the radiologic severity of OA by their absolute values and the number of pa-tients achieving the patient acceptable symptomatic state (PASS). Serial changes in the clinical outcomes in each subgroup were also assessed. Results: Of the 43 patients, 14, 18, and 11 were classified as the stage I, II, and III groups, respectively; the mean follow-up duration was 71.3 +/- 28.9 months, and the mean age was 56.5 +/- 7.2 years. At medium-term follow-up, the stage I group had a better ROM arc (stage I, 114 degrees +/- 14 degrees; stage II, 100 degrees +/- 23 degrees; and stage III, 97 degrees +/- 20 degrees; P =.067) and VAS pain score (stage I, 0.9 +/- 1.3; stage II, 1.8 +/- 2.1; and stage III, 2.4 +/- 2.1; P = .168) than the stage II and III groups without reaching statistical significance, whereas the stage I group had a significantly better MEPS (stage I, 93.2 +/- 7.5; stage II, 84.7 +/- 11.9; and stage III, 78.6 +/- 15.2; P = .017) than the stage III group. The percentages of patients achieving the PASS for the ROM arc (P = .684) and VAS pain score (P = .398) were comparable between the 3 groups; however, the percentage achieving the PASS for the MEPS was significantly higher in the stage I group than in the stage III group (100.0% vs. 54.5%, P = .016). During serial assessment, all clinical outcomes tended to improve at the short-term follow-up. Compared with the short-term period, the ROM arc tended to decrease at the medium-term follow-up whereas the VAS pain score and MEPS overall did not show significant changes. Conclusion: After arthroscopic OCA, the stage I group showed an overall better ROM arc and pain score than the stage II and III groups at medium-term follow-up, whereas the stage I group showed a significantly better MEPS and higher percentage of patients achieving the PASS for the MEPS than the stage III group. Level of evidence: Level III; Retrospective Cohort Comparison; Prognosis Study (c) 2023 Published by Elsevier Inc. on behalf of Journal of Shoulder and Elbow Surgery Board of Trustees.