Analgesic Efficacy of Anterior Femoral, Genicular and Adductor Canal Nerve Block

Postoperative pain associated with total knee arthroplasty (TKA) can pose significant challenges in the recovery process of the patients undergoing this procedure. Traditionally, opioids have played a significant role in treating postoperative pain. It is well established that opioids are highly effective in relieving pain at rest, but are less effective in relieving pain associated with motion (e.g. ambulation, passive motion, and physical rehabilitation). Furthermore, the use of opioids for analgesia is associated with well-known side effects (such as: nausea, vomiting, constipation, ileus, bladder dysfunction, respiratory depression, pruritus, drowsiness, sedation, and allergic reaction). These opioid side effects, which range in severity, can significantly interfere with the rehabilitation process and contribute to a delay in hospital discharge. Significant interest exists in the application of regional anesthetic techniques as an adjuvant to traditional opioid analgesics for pain control in patients after TKA. Specifically, the incorporation of femoral nerve blocks (FNB) as an adjunct in postoperative pain control has been widely reported in the anesthesia literature. While it has shown to be effective in post-operative pain control, it has introduced additional challenges for physical therapy and raised new concerns regarding the associated quadriceps muscle weakness. Until adequate quadriceps function returns, the need for knee immobilization devices to protect patients with traditional FNB from falls interferes with the early recovery process and the achievement of physical therapy milestones.