Evaluation of analgesic regimens in total knee arthroplasty, retrospective study

Analgesic therapies have an immense role in early rehabilitation period after total knee arthroplasty (TKA) and multimodal approaches should be considered as the first choice of treatment. In this retrospective study, the aim was to evaluate the effectiveness of multimodal analgesic therapies for TKA, including femoral nerve block (FNB) and patient controlled analgesia (PCA).

The data of 79 patients who underwent TKA between January and December 2016 were retrospectively evaluated. In all, 63 patients met the inclusion criteria. Hemodynamic records and Visual Analogue Scale (VAS) pain scores for postoperative 0, 2, 4, 6, 9, and 12 hours were evaluated and patients were separated into 3 groups. Group 1: FNB with 0.25% bupivacaine, Group 2: FNB with 0.166% bupivacaine, and Group 3: No FNB.

The average age of the patients was 64.3±14.9 years and average body mass index (BMI) was 32.5±5.3 kg/m². There was no statistical difference between groups in age, gender, American Society of Anesthesiologists (ASA) classification of physical health scores, BMI, or anesthesia type (p<0.05). When VAS scores at postoperative time intervals were compared, there was a statistically significant difference between Group 1 and Group 2 (p>0.05). When difference between Groups 1 and 3 and Groups 2 and 3 were compared, the difference was statistically significant for VAS 0 (p>0.05). Additional analgesic use was highest in Group 3.

This study demonstrated that FNB significantly decreases postoperative pain intensity and additional analgesia requirement in patients undergoing TKA. A concentration of 0.166% bupivacaine is as effective as a concentration of 0.25% when used as part of a multimodal analgesia regimen in TKA.