Continuous Adductor Canal Blockade In Perioperative Pain Management For Total Knee Replacement

BACKGROUND: Total knee replacement (TKR) is one of the commonly performed orthopedic procedures and remains the only definitive method for relieving pain and improving quality of life in patients with knee osteoarthritis. Despite significant progress in pain management, there is still no consensus on the optimal approach to postoperative analgesia in this patient population.

AIM: To compare the efficacy and safety of three prolonged postoperative analgesia techniques following TKR: continuous epidural analgesia (CEA — control group), continuous adductor canal block (CACB), and a combination of CACB with infiltration between the popliteal artery and the capsule of the knee (IPACK) — CACB+IPACK.

METHODS: Patients were enrolled between December 2023 and June 2024. A total of 184 patients aged 60 years and older were randomized into three groups: CEA (n=62), CACB (n=60), and CACB+IPACK (n=62). The primary endpoint was the proportion of patients achieving effective analgesia at 24 hours postoperatively. Secondary endpoints included muscle strength assessed using the Medical Research Council (MRC) Scale for Muscle Strength, presence of posterior knee pain at 24 hours, length of hospital stay, opioid analgesic requirements, and patient satisfaction with anesthesia measured by the QoR-40 questionnaire.

RESULTS: Effective analgesia was achieved in 70% of patients in the CACB group, compared to 91.9% in the CEA group (OR 0.21; 95% CI 0.07–0.6; p=0.0036). In the CACB+IPACK group, 90.3% of patients achieved effective analgesia, not significantly different from the CEA group (OR 0.81; 95% CI 0.24–2.84; p=0.752). Posterior knee pain was significantly more common in the CACB group (63.3%) compared to the CEA (14.5%) and CACB+IPACK (17.1%) groups (p <0.001). Muscle weakness rated as 4 on the MRC scale persisted at 28 hours in the CEA group. Tramadol use was required in 80% of cases in the CACB group, significantly more often than in the other groups. The duration of hospital stay was significantly longer in the CEA group. According to the QoR-40 questionnaire, patient satisfaction with anesthesia was higher in both peripheral nerve blockade groups.

CONCLUSIONS: CACB alone provided significantly less effective analgesia compared to CEA. However, the combination of CACB with IPACK demonstrated comparable efficacy to CEA.