6-week cryo-compression therapy and opioid use after unicompartmental knee arthroplasty with comparable pain scores: a secondary analysis of a randomized controlled trial

BACKGROUND AND PURPOSE: Cryo-compression benefits after knee arthroplasty appear short-lived. Evidence in unicompartmental knee arthroplasty (UKA) is particularly scarce. We aimed to assess 6-week cryo-compression on pain (including oxycodone consumption), function, and quality of life (QoL) at 6 weeks following UKA compared with standard care. METHODS: In this single-center, single-blind randomized controlled trial (NCT05572359), adults scheduled for UKA were randomly assigned (1:1) to the regular or cryo-compression group. The cryo-compression group was instructed to use the cold compression brace 5 times daily for 6 weeks. Primary outcome (Numeric Rating Scale [NRS] pain at rest) and secondary outcomes (NRS pain during loading, Knee Injury and Osteoarthritis Outcome Score-subscales, Oxford Knee Score, Work, Osteoarthritis and joint-Replacement Questionnaire [WORQ], physical tests, EuroQol 5-Dimensions 5-Level [EQ5D-5L]) were measured preoperatively and at 6 weeks. Oxycodone consumption was recorded daily. RESULTS: At 6 weeks, there was no between-group difference in pain at rest (mean difference 0.1 points, CI -0.6 to 0.9). The cryo-compression group consumed 46% less oxycodone over the 6 weeks (CI 9-68), with an absolute median difference of 3.5 5-mg tablets in total. WORQ and EQ5D-5L index-scores improved more in the cryo-compression group (8.7 points, CI 0.7-16.6, and 0.10 points, CI 0.03-0.2, respectively), but neither reached the minimal clinically important difference (13 and 0.11). CONCLUSION: 6-week cryo-compression following UKA demonstrated no differences in pain at rest or functional and QoL-related outcomes. Oxycodone consumption was lower in the cryo-compression group, although absolute differences were small.