Intraoperative Posterior Cruciate Ligament (Transcruciate) Injection After Total Knee Arthroplasty (TKA)

Study Overview
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Brief Summary
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his study is being done because total knee replacements can leave patients with considerable pain after surgery. Therefore, many studies have been done to find the best ways to control knee pain after the surgery. Currently, a popular approach is to use many different techniques to control the pain. This includes injecting freezing (local anesthetic) into the spinal column (spinal anesthetic), injecting freezing close to the nerves of the knee and using various kinds of medications (e.g. narcotics and anti-inflammatory medications). Studies have shown using this a combination of techniques can reduce pain and allow earlier discharge from the hospital. However, one downside to this approach is it does not usually control the pain in the back of the knee. One new technique has been used to try and overcome this. This technique is called a posterior cruciate ligament block or PCL block. It involves injecting a drug into the back of the knee which will block the nerves in this area. Sometimes the investigators refer to this as freezing. The purpose of our study is to determine whether this PCL Block will improve pain after the total knee replacement surgery. The investigators will also determine whether this technique will improve movement in the knee and lessen narcotic usage after the surgery.

Official Title
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Reducing Posterior Knee Pain Following Total Knee Arthroplasty Using an Intraoperative Posterior Cruciate Ligament (Transcruciate) Injection

Conditions
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Arthroplasty, Replacement, Knee

Intervention / Treatment
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* Procedure: transcruciate injection of 20cc of normal saline
* Procedure: transcruciate injection of 20 cc of 0.5% Ropivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists' (ASA) physical status classification (ASA) I and II patients undergoing unilateral total knee arthroplasty at Saskatoon City Hospital Patients recruited from the practice of 4 orthopedic surgeons Exclusion Criteria: Inability to obtain informed consent Simultaneous bilateral total knee arthroplasty or revision cases Preexisting neurological deficits in the distribution of the femoral nerve or known diagnosis of peripheral neuropathy Coagulopathies Infection either systemically or at the needle insertion sites Allergies to local anesthetics or opioids Patients with a history of narcotic dependency or chronic pain ASA III and IV Body Mass Index (BMI) > 40

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Saline<br> | Procedure: transcruciate injection of 20cc of normal saline<br>* Group 2 (control group) will receive a transcruciate injection of 20cc of normal saline through the posterior cruciate ligament during the procedure (in addition to a subarachnoid block and femoral nerve block pre-operatively).<br>|
| Active Comparator: Ropivicaine<br> | Procedure: transcruciate injection of 20 cc of 0.5% Ropivacaine<br>* Group 1 (study group) will receive a transcruciate injection of 20 cc of 0.5% Ropivacaine through the posterior cruciate ligament during the procedure (in addition to a subarachnoid block and femoral nerve block pre-operatively).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee flexion |  | up to one week postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Postoperative pain score | Pain scores will be recorded at rest and on attempt of achieving a 90 degree passive flexion of the knee. | in PACU , on ward (baseline), and post-op day 1 & 2 at 10am & 6pm | 
| Total narcotic consumption |  | up to 1 week postoperative |