title: Pain After Unilateral Total Knee Arthroplasty: A Prospective Randomized Controlled Trial Examining the Analgesic Effectiveness of a Combined Adductor Canal Peripheral Nerve Block with Periarticular Infiltration Versus Adductor Canal Nerve Block Alone Versus Periarticular Infiltration Alone.
abstract: Total knee arthroplasty is a painful surgery that requires early mobilization for successful joint function. Multimodal analgesia, including spinal analgesia, nerve blocks, periarticular infiltration (PI), opioids, and coanalgesics, has been shown to effectively manage postoperative pain. Both adductor canal (AC) and PI have been shown to manage pain without significantly impairing motor function. However, it is unclear which technique is most effective. This 3-arm trial examined the effect of AC block with PI (AC + PI) versus AC block only (AC) versus PI only (PI). The primary outcome was pain on walking at postoperative day (POD) 1.
  
  
  
  One hundred fifty-one patients undergoing unilateral total knee arthroplasty were included. Patients received either AC block with 30 mL of 0.5% ropivacaine or sham block. PI was performed intraoperatively with a 110-mL normal saline solution containing 300 mg ropivacaine, 10 mg morphine, and 30 mg ketorolac. Those patients randomly assigned to AC only received normal saline knee infiltration.
  
  
  
  On POD 1, participants who received AC + PI reported significantly lower pain numeric rating scale scores on walking (3.3) compared with those who received AC (6.2) or PI (4.9) (P < 0.0001). Participants who received AC reported significantly higher pain scores at rest and knee bend compared with those who received AC + PI or PI (P < 0.0001). The difference in pain scores between participants who received AC + PI and those who received AC was 2.83 (95% confidence interval, 1.58-4.09) and the difference between those who received AC + PI and those who received PI was 1.61 (95% confidence interval, 0.37-2.86). On POD 2, participants who received AC + PI reported significantly less pain on walking (4.4) compared with those who received AC (5.6) or PI (5.6) (P = 0.006). On POD 2, there was no difference between the groups for pain at rest or knee bending. Participants who received AC used more IV patient-controlled analgesia on POD 0. There was no difference between the groups regarding distance walked.
  
  
  
  Participants who received AC + PI reported significantly less pain on walking on PODs 1 and 2 compared with those who received AC only or PI only.
authors.affiliation: From the *Faculty of Health Sciences, School of Nursing, Queen's University, Kingston, Ontario, Canada; †Peri-operative Services, North York General Hospital, Toronto, Ontario, Canada; ‡Department of Surgery, University of Toronto, Toronto, Ontario, Canada; §Department of Anaesthesia, University of Toronto, Toronto, Ontario, Canada; and ‖Department of Anaesthesia, Canadian Institute for Health Information, Toronto, Ontario, Canada.
authors.forename: Monakshi
authors.initials: M
authors.lastname: Sawhney
authors.forename: Hossein
authors.initials: H
authors.lastname: Mehdian
authors.forename: Brian
authors.initials: B
authors.lastname: Kashin
authors.forename: Gregory
authors.initials: G
authors.lastname: Ip
authors.forename: Maurice
authors.initials: M
authors.lastname: Bent
authors.forename: Joyce
authors.initials: J
authors.lastname: Choy
authors.forename: Mark
authors.initials: M
authors.lastname: McPherson
authors.forename: Richard
authors.initials: R
authors.lastname: Bowry
mesh_terms: D000368:Aged; D000577:Amides / Q000008:administration & dosage* / Q000009:adverse effects; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D004311:Double-Blind Method; D004434:Early Ambulation; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000294:innervation* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000009:adverse effects / Q000379:methods*; D009864:Ontario; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects; D010149:Postoperative Pain / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D011446:Prospective Studies; D020127:Recovery of Function; D000077212:Ropivacaine; D013997:Time Factors; D016896:Treatment Outcome; D016138:Walking
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine