Epidural versus intra-articular infusion analgesia following total knee replacement

To compare the efficacy of epidural versus intra-articular infusion analgesia following total knee replacement (TKR).

25 men and 50 women aged 55 to 75 (mean, 67) years who underwent primary TKR by a single surgeon were randomised and consented to receive either epidural (n=35) or intra-articular (n=40) infusion analgesia for 48 hours at 5 ml/ hr. All patients also received intravenous aqueous diclofenac 50 mg twice a day. Patients were assessed 6 hourly for visual analogue score (VAS) for pain to determine the analgesic effect. Complications such as paraesthesia in the lower limbs, hypotension, urinary retention, and abdominal distension were recorded, as was the rehabilitation progress with respect to the time to stand, climb stairs, use of commode chair, and discharge.

The epidural and intra-articular infusion groups were comparable with respect to age, sex, weight, and operating time, as was the analgesic efficacy within 48 hours of TKR. Patients with epidural infusion analgesia had a higher complication rate in terms of hypotension (51.4% vs. 22.5%, p=0.015) and troublesome paraesthesia in the lower limbs (45.7% vs. 12.5%, p=0.028), and a trend of higher abdominal distension rate (20% vs. 5%, p=0.073). Patients with intra-articular infusion analgesia were able to stand/ walk earlier (2.08 vs. 2.54 days, p<0.001). The 2 groups did not differ significantly in the time needed to climb stairs, use of commode chair, and discharge.

The efficacy of epidural and intraarticular infusion analgesia was comparable. Intra-articular infusion was associated with fewer complications and earlier rehabilitation.