Analgesia After Total Knee Arthroplasty

University of Manitoba90 enrolled

Overview

The recovery from knee replacement surgery often involves a significant amount of pain. The best way to prevent/treat this pain is unknown. This study will compare two accepted methods of pain control in order to determine which is superior. The first method involves the injection of a solution containing multiple medications into the knee joint at the time of surgery. The second method involves the placement of a catheter adjacent to the femoral nerve which senses pain from the knee. This catheter is used to deliver local anesthetic which serves to block the transmission of pain signals from the nerve. The catheter will be left in place until 2 days after surgery. This method is combined with injection of local anesthetic in a particular area of the knee joint at the time of surgery. Patients will be followed until 2 days after surgery in order to determine which method is superior. We believe the second method will be deemed superior.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

Conditions

Analgesia

Interventions

A 20 ml bolus of saline will be given through the sham femoral nerve block catheter. Periarticular infiltration solution containing 400 mg Ropivicaine, 30 mg Ketorolac, 5 mg Epidural Grade Morphine, and 0.6 ml of 1:1000 Epinephrine will be made up to a volume of 100 ml with saline. Intra-op, 20 ml will be injected into the posterior capsule; 40 ml in the quadriceps mechanism, retinacular tissues, medial and lateral collateral ligaments; 40 ml in the skin and subcutaneous tissues. The sham catheter will be connected to a saline infusion running at 15 ml/hr until the morning of post-operative day 2.

CFNB + Posterior Capsular InjectionDRUG

A 20 ml bolus of 0.2% Ropivacaine will be given via a femoral nerve catheter. Periarticular infiltration will be performed intra-op. 20 ml of 1% Ropivacaine in the posterior capsule; 20 ml of normal saline in the quadriceps mechanism, retinacular tissues, medial and lateral collateral ligaments; 20 ml of normal saline for the skin and subcutaneous tissues. Postoperatively, the femoral catheter will be infused with 0.15% Ropivacaine running at 15 ml/hour until the morning of post-operative day 2

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

Inclusion Criteria: * ASA I, II, \& III patients * Elective primary total knee arthroplasty * Spinal Anesthesia Exclusion Criteria: * Patients refusing consent * Contraindications to regional anesthesia * Pre-existing neurological disease * Allergy/contraindication to drugs used in the study * Revision knee arthroplasty * Patients with chronic pain/on narcotics preoperatively * Pre-existing Rheumatoid Arthritis/Ankylosing Spondylitis * Alcohol or drug abuse * Psychiatric disorders * Inability to use the outcome assessment tools * Wheel chair or walker dependent for mobilization

Outcomes

Primary Outcomes

Static and dynamic pain scores until post-operative day 2 (POD 2)

Time frame: 9:00 and 15:30 daily for the first 2 postoperative days