Pre-emptive injection of peri-articular-multimodal drug for post-operative pain management in total knee arthroplasty: a double-blind randomized clinical trial.

PURPOSE: Severe post-operative pain is one of the main problems after total knee arthroplasty. In this study, we investigated the effect of a peri-articular multimodal drugs injections pre-emptively on post-operative pain control and knee functions following total knee arthroplasty.

METHODS AND MATERIALS: This study was a double-blind randomized clinical trial. Eligible cases including 137 patients-aged 30 to 80 years old-were randomly divided into one of two groups: the drug group received a cocktail consisting of bupivacaine hydrochloride, morphine sulphate, epinephrine, and ketorolac. The control group received epinephrine only. The injections were given 15 minutes before incision. Joint range of motion (ROM) and the severity of pain by using visual analog scale (VAS) of 1 to 10 and patient's facial expression, were assessed in the pre-operative visit, after 24 hours, 48 hours, and six weeks after operation. Knee Society score (KSS) was recorded before the operation, six weeks, and six months after the operation for each patient.

RESULTS: The data of VAS showed no significant difference between the groups before operation but there was statistically significant difference between the two groups at 24 hours, 48 hours, and six weeks after the operation. In KSS, difference was not significant between the two groups before the operation and six months after surgery while our results showed a statistically significant difference between groups six weeks after the operation. In ROM, there was no significant difference between the groups before operation. There was a statistically significant difference between the two groups at 24 hours, 48 hours and six weeks after the operation. Complications were recorded at six weeks after surgery.

CONCLUSION: Peri-articular multimodal injection including bupivacaine, morphine, and ketorolac preferably with pre-emptive injection method provided proper post-operative pain relief, less opioid consumption, and better early rehabilitation following TKA at 48 hours after surgery.

LEVEL OF STUDY: Level I.