Prolonged Adductor Canal Block in Perioperative Analgesia for Total Knee Arthroplasty in Elderly and Senile Patients: An Open Randomized Study

BACKGROUND: Total knee arthroplasty (TKA) is among the most frequently performed orthopedic procedures and often represents the only effective method to relieve pain and improve quality of life in patients with knee osteoarthritis. Despite advances in pain management, no universally accepted or standardized strategy for analgesia in this population has been established.

AIM: The work aimed to compare the efficacy and safety of three prolonged postoperative analgesia techniques for TKA: prolonged epidural analgesia (PEA, control group), prolonged adductor canal block (PACB), and a combination of PACB with infiltration between the popliteal artery and the posterior capsule of the knee (iPACK)—PACB+iPACK.

METHODS: Patient were enrolled between December 2023 and June 2024. A total of 184 patients aged 60 years and older were analyzed and randomized into three groups: the control group with PEA (n = 62), PACB (n = 60), and PACB+iPACK (n = 62). The primary endpoint was the proportion of patients who achieved effective analgesia 24 hours after surgery. Secondary endpoints included muscle strength assessment using the Medical Research Council (MRC) Weakness Scale, posterior knee pain 24 hours after surgery, length of hospital stay, opioid analgesic consumption, and patient satisfaction with anesthesia measured by the Quality of Recovery Questionnaire (QoR-40).

RESULTS: In the PACB group, the proportion of patients who achieved effective analgesia was 70%, compared with 91.9% in the control group (OR = 0.21; 95% CI, 0.07–0.6; p = 0.0036). When comparing the control group with the PACB+iPACK group, the rates were 91.9% and 90.3%, respectively (OR = 0.81; 95% CI, 0.24–2.84; p = 0.752). Posterior knee pain was significantly more frequent in the PACB group: it was recorded in 9 patients (14.5٪) in the control group, 38 (63.3٪) in the PACB group, and 11 (17.1٪) in the PACB+iPACK group (p < 0.001; p_PEA/PACB < 0.001; p_{PACB/PACB+iPACK} < 0.001). In the PEA group, a muscle weakness score of 4 points on the MRC scale persisted even after 28 hours. In 80٪ of cases in the PACB group, tramadol administration was required. The length of hospital stay was significantly longer in the control group compared with the other groups. According to the QoR-40 questionnaire, patient satisfaction with anesthesia was higher in the groups of peripheral nerve blocks.

CONCLUSION: The analgesic efficacy of PACB was significantly lower than that of PEA. However, the combination of PACB + iPACK provided analgesia similar to that achieved with PEA.