Adductor Canal Block Versus Periarticular Infiltration Effect on Functional Outcome In Patients Undergoing Total Knee Replacement

Osteoarthritis (OA) of the knee has become a major public health issue and imposes a significant healthcare burden and accounts for high annual hospitalizations. Chronic OA of the knee may lead to reduced physical fitness, mobility disability with a resultant increased risk of cardio-metabolic comorbidity and early mortality. Total knee arthroplasty (TKA) is indicated in severe cases to improve long-term pain and function. (1) TKA involves extensive bone resection as well as soft tissue excision and therefore is associated with profound postoperative pain. (2) Inadequate perioperative pain control may prolong hospitalization, hinder early rehabilitation, and is also a strong predictor of persistent pain beyond 3 months. (3) Adequate analgesia after TKA is therefore considered paramount to facilitate early hospital discharge and effective functional recovery. (4) The recently introduced adductor canal block (ACB) typically covers the anterio-medial aspect of the knee and preserves quadriceps function, which presumably enhances postoperative rehabilitation by allowing patients to actively participate in knee movement. The relative effectiveness of this ACB technique added to intrathecal morphine is limited to a single study (1) in which assessment of short-term functional recovery was done and dexamethasone was neither included in the LIA solution nor perineurally in the ACB. Thus, we hypothesize that adductor canal block as an adjunct to intrathecal morphine will have a better impact on functional recovery than peri-articular infiltration.