Comparative Effectiveness of Peri-Articular and Single-Shot Intra-Articular Injections in Patients Undergoing Total Knee Replacement

Abstract

Objective : To compare the effectiveness of peri-articular injections and single-shot intra-articular injection in postoperative pain control following total knee arthroplasty (TKA). The study was conducted at Kamphaeng Saen Hospital between October 1, 2021, and September 30, 2022 (12 months).

Methods : This was a prospective randomized controlled trial involving 60 patients (60 knees) who underwent primary TKA. Patients were randomly assigned into two groups using sealed sequentially numbered envelopes. Group 1 (peri-articular injection group) received analgesic infiltration into the muscles and soft tissues surrounding the knee joint. Group 2 (single-shot intra-articular injection group) received analgesic injection into the joint cavity once after wound closure. Pain intensity was compared between groups at 24, 48, and 72 hours postoperatively. Outcome measures included pain scores and severity of osteoarthritis evaluated using the Oxford Knee Score (OKS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and International Knee Documentation Committee (IKDC) score. Data were analyzed using frequency, percentage, mean, standard deviation, independent t-tests, and one-way repeated measures ANOVA.

Result : The osteoarthritis severity scores evaluated using OKS, WOMAC, and IKDC did not differ significantly between the two groups across all time points. However, the single-shot intra-articular injection group reported significantly lower postoperative pain scores at 24, 48, and 72 hours compared to the peri-articular injection group (p < 0.01).

Conclusion : Single-shot intra-articular injection is more effective than peri-articular injection in reducing postoperative pain after total knee arthroplasty, while both techniques show no significant difference in osteoarthritis severity outcomes.