The aim of this study was to compare the efficacy of combined periarticular and incisional injections versus periarticular injection alone of bupivacaine in reducing post-operative pain after total knee arthroplasty (TKA).
In this prospective, randomized, double-blind comparative study, 90 patients with primary osteoarthritis who underwent TKA were enrolled. The patients were then randomly divided into 3 groups (30 in each): group 1, without injection; group 2, with periarticular injection of 20 mL 0.5% bupivacaine hydrogen chloride (HCl) (100 mg) after implantation; and group 3, periarticular injection of 20 mL 0.5% bupivacaine HCl (100 mg) after implantation and incisional injection of 10 mL 0.5% bupivacaine HCl (50 mg) before wound closure. Post-operative pain levels were measured using a 100-mm visual analogue scale (VAS) (0 mm: no pain and 100 mm: worst pain) at 30 min and 1, 2, 4, and 6 h, post-operatively.
The mean VAS score in group 3 (the combined group-periarticular and incisional injections) within the first 4 h was lower than that in group 1 and group 2 (p<0.001). The mean VAS scores at the first 30 min were 65.21±9.46 in group 1, 51.86±5.96 in group 2, and 29.33±8.55 in group 3 (p<0.001). The mean VAS scores at the first 1 h were 64.43±9.32 in group 1, 47.26±4.77 in group 2, and 31.66±7.37 in group 3 (p<0.001). The mean scores at the 2 h were 61.46±8.62 in group 1, 48.33±4.66 in group 2, and 30.83±6.76 in group 3 (p<0.001). The mean scores at the 4 h were 64.72±8.91 in group 1, 47.53±4.35 in group 2, and 34.36±6.64 in group 3 (p<0.001). The differences were not significant at 6 h between group 2 (44.91±4.12) and group 3 (41.83±6.71) (p>0.001). However, the values were significantly lower than those of the control group (63.56±9.73) (p<0.001). In addition, VAS scores at all follow-up times were significantly higher in the control group compared with the other groups (p<0.001).
Level I, Therapeutic study.
Evidence from this study revealed that the combined injection of bupivacaine is more effective than its periarticular injection alone and provides effective post-operative pain management after TKA.