Efficacy of adductor canal and popliteal plexus block combined with local anesthetic injection in the interspace between the popliteal artery and posterior capsule of the knee and local infiltrative analgesia for postoperative pain and functional outcome after total knee arthroplasty: A randomized controlled study.

ABSTRACT

BACKGROUND: Adductor canal block and periarticular infiltration analgesia (PIA) have been shown to relieve pain in total knee arthroplasty (TKA) effectively. However, their analgesic effectiveness has some limitations. Thus, we considered a novel blocking site that could achieve analgesia without affecting the muscle strength of the lower limbs. METHODS: Seventy-two patients undergoing primary unilateral total knee arthroplasty were randomized into two groups. One group was treated with adductor canal and popliteal plexus (APB) combined with interspace between the popliteal artery and posterior capsule of the knee (iPACK) and local infiltration anesthesia (LIA) and the other was treated with PIA. The primary outcomes included postoperative pain, as assessed by the visual analog scale (VAS), and the consumption of oral tramadol. Secondary outcomes included functional recovery and daily ambulation distance. Tertiary outcomes included postoperative adverse effects. RESULTS: The APB group had lower VAS scores after surgery at rest and during motion. Compared with the PIA group, the walking distance of the APB group on the second day was greater. The muscle strength of the APB group was lower than that of the PIA group at the early stage. Patients in the APB group also consumed less tramadol than those in the PIA group. There was no difference in the incidence of adverse events between the two groups. CONCLUSIONS: APB combined with iPACK and LIA is a novel block for TKA, and it can reduce postoperative pain sooner after TKA without affecting postoperative functional recovery or increasing complications.