Abstract
BACKGROUND: Knee arthroplasty is an established treatment for degenerative and inflammatory knee disorders. Effective perioperative analgesia is essential for early mobilisation and same-day discharge. This study evaluated the relationship between different regional anaesthesia techniques, postoperative pain, and same-day discharge rates in knee arthroplasty patients. METHODS: We evaluated 100 consecutive patients as part of a service evaluation of our established knee arthroplasty pathway. Four regional anaesthesia strategies were used: adductor canal block (ACB) only, ACB + genicular, ACB + IPACK (infiltration of popliteal artery and capsule of the knee), and no block. Pain was assessed using a verbal rating scale (0–3) at 2, 6, 12, and 24 h postoperatively. Patient demographics, anaesthetic technique, surgical type and discharge status were recorded. Group comparisons were statistically analysed and predictors of same-day discharge were assessed adjusting for age, gender, BMI, and mean 24-h pain score and surgical type. RESULTS: Mean 24-h pain score for the cohort was 1.05 ± 0.81, with women reporting higher scores than men (p-value 0.023). Higher pain scores were independently associated with reduced odds of same-day discharge (OR 0.32, p-value 0.002). Across the four block modalities, mean pain scores did not differ significantly (p-value 0.968). Using no block as the reference, ACB + genicular was associated with higher odds of same-day discharge (OR 5.29, p-value 0.035). Younger age (p-value 0.022) and higher BMI (p-value 0.044) were also significant predictors; gender and ASA grade were not. CONCLUSION: While overall pain scores were similar between block types, higher pain was independently associated with lower likelihood of same-day discharge. In this observational cohort, ACB + genicular was independently associated with same-day discharge following adjustment for confounders. Further work is needed to determine whether these associations are reproducible across centres and patient populations.