Lumbar Epidural Corticosteroid Injection Reduces Subacute Pain and Improves Knee Function in the First Six Weeks After Total Knee Arthroplasty: A Double-Blinded Randomized Trial.

BACKGROUND: Pain control immediately following total knee arthroplasty (TKA) has been a focus for orthopaedists. However, control of subacute pain, which may persist up to 3 months, is usually not optimized. The efficacy of epidural corticosteroids in reducing pain after surgery is documented, but data on their efficacy in controlling subacute pain after TKA are lacking. Our aim was to investigate the efficacy of an epidural corticosteroid in controlling pain in the first 3 months following TKA using a double-blinded randomized clinical trial.

METHODS: One hundred and eight patients with osteoarthritis of the knee who underwent TKA and received analgesic drugs through an epidural catheter for 48 hours were randomized to receive either 40 mg (1 mL) of triamcinolone acetonide plus 5 mL of 1% lidocaine, or 6 mL of 1% lidocaine alone before catheter removal. The outcomes of interest were pain level during motion and at rest, knee function, and range of motion, which were recorded up to 3 months after surgery. Multilevel regression models were used to estimate the differences between groups.

RESULTS: The corticosteroid + lidocaine group had a lower average level of pain during motion compared with the lidocaine-only group, as measured by a visual analog scale (VAS), from day 3 to 7 weeks postoperatively (p < 0.05). At 7 weeks, the mean difference was -7 points (95% confidence interval [CI], -12.8 to -1.0 points; p = 0.033). The corticosteroid + lidocaine group also had a better mean overall modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 6 weeks postoperatively (28 compared with 33 points; 95% CI, -8.6 to -0.6 points; p = 0.03). There was no difference between the groups in the level of pain at rest and knee range of motion during the 3-month period (p > 0.05).

CONCLUSIONS: Lumbar epidural corticosteroid injection reduced pain during motion for 7 weeks and provided better knee function at 6 weeks postoperatively compared with lidocaine alone. There was no difference detected with respect to pain at rest and knee range of motion during the 3-month follow-up. Epidural corticosteroids could improve patient satisfaction during the early weeks of recovery after TKA.

LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.