Association between regional anaesthesia strategies, postoperative pain and same-day discharge following knee arthroplasty: a single-centre service evaluation

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. 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. 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. 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. Evaluates the effect of four regional anaesthesia strategies (ACB only, ACB + genicular, ACB + IPACK, no block) on pain and same-day discharge after knee arthroplasty. Finds no significant difference in 24-hour mean pain scores between ACB only, ACB + genicular, ACB + IPACK, and no block. Identifies higher pain scores as independently associated with reduced likelihood of same-day discharge. ACB + genicular was independently associated with higher odds of same-day discharge compared with no block. Reports younger age and higher BMI as significant predictors of same-day discharge, while gender and ASA grade were not.