Long term effect of steroid in local infiltration analgesia after total knee arthroplasty. A paired-randomised controlled Trial

Abstract

Introduction: Total knee arthroplasty (TKA) is the most successful treatment for advance osteoarthritis; however, severe post-operative pain remains unresolved. Sufficient analgesia is important for immediate mobilisation and rehabilitation. Local infiltration analgesia (LIA) is effective in relieving pain after TKA, however, the optimal cocktail combination and its individual roles are unclear. Corticosteroid in LIA has shown to improve early rehabilitation outcomes, however, its long term effect and safety is uncertain. Objectives: To evaluate the long term effects and safety of steroid in LIA. Methodology: This is a paired-randomised controlled study approved by Institutional Review Board. Patients undergoing one-stage bilateral TKA were recruited. Peri-operative analgesics were standardised. LIA containing ropivacaine, ketorolac, adrenaline with or without triamcinolone was given. Each knee of same patient was randomised to receive LIA with or without steroid. Primary outcome includes differences in complications and functional scorings (Knee Society Score (KSS) and Oxford Knee Score (OKS)) up to one year follow-up. Secondary outcome includes differences in Visual Analogue Scale (VAS) and rehabilitation parameters between both knees of same patient. Results: 45 patients (90 TKAs) were included. LIA with steroid knees showed significantly lower VAS at rest and during activity from day one to six weeks (p<0.05). Active and passive knee range was greater in steroid treated knee from day one to day seven (p<0.05). Time to active straight leg raise was shorter in steroid group (p<0.05). Up to one year follow-up, no infection, wound complications or tendon ruptures in all knees. KSS and OKS were comparable at one year. Conclusion: Steroid in LIA can improve early pain control and recovery after TKR, while no increase in long term complications were found. It is effective and safe. This has important clinical significance in setting of fast-track arthroplasty.