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.

ABSTRACT

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 Performance 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 classification. Clinical outcomes were compared according to the radiologic severity of OA by their absolute values and the number of patients 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° ± 14°; stage II, 100° ± 23°; and stage III, 97° ± 20°; 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.