Evaluation of Utility of Ultrasound Guided iPACK Block for Knee Extension After Total Knee Arthroplasty.

Phase 4

Completed

Conditions: Primary Total Knee Arthroplasty
Pain
Knee Extension
Physical Therapy
Knee Osteoarthritis

Interventions: Procedure: Interspace Between the Popliteal Artery and Capsule of the Knee (iPACK) Block
Drug: Ropivacaine
Drug: Saline

Brief Summary: The purpose of this study is to learn if using an Interspace between the Popliteal Artery and Capsule of the Knee (iPACK) injection technique (also called a "nerve block") that numbs the nerves going to the back part of the knee to aid in physical therapy after surgery. The iPACK technique uses a numbing solution (local anesthetics) that is injected behind the knee to reduce pain and to help straighten the knee. This block may affect movement in the leg and make the legs weak, but thing is rare. A few institutions use the iPACK block for patients having total knee replacements, with the hope of providing good pain relief combined with improved mobility after surgery.

Recruitment & Eligibility

Inclusion Criteria

English speaking
Between 18 and 75 years old
American Society of Anesthesiologists (ASA) 1-3 patients undergoing primary total knee arthroplasty

Exclusion Criteria

ASA 4 or 5
Revision knee arthroplasty
Diagnosis of chronic pain
Daily chronic opioid use (over 3 months of continuous opioid use)
Inability to communicate pain scores or need for analgesia
Acute knee dislocation/fracture
Infection at the site of block placement
Age under 18 years old or greater than 75 years old
Pregnant women
Intolerance/allergy to local anesthetics
Weight <50 kg
Suspected, or known addiction to or abuse of illicit drug(s), prescription medicine(s), or alcohol within the past 2 years.
Uncontrolled anxiety, schizophrenia, or other psychiatric disorder that, in the opinion of the investigator, may interfere with study assessments or compliance
Current or historical evidence of any clinically significant disease or condition that, in the opinion of the investigator, may increase the risk of surgery or complicate the subject's postoperative course.

Arm && Interventions

Group	Intervention	Description
Sham Group	Interspace Between the Popliteal Artery and Capsule of the Knee (iPACK) Block	The same nerve block technique as above, however using an inactive solution of salt water.
Sham Group	Saline	The same nerve block technique as above, however using an inactive solution of salt water.
iPACK Block Group	Interspace Between the Popliteal Artery and Capsule of the Knee (iPACK) Block	A nerve block technique using a numbing medication called ropivacaine.
iPACK Block Group	Ropivacaine	A nerve block technique using a numbing medication called ropivacaine.

Primary Outcome Measures

Name	Time	Method
Number of Participants Able to Hyperextend the Knee After Surgery	Within 8 hours	Ability to hyperextend the knee after surgery

Secondary Outcome Measures

Name	Time	Method
Cumulative Opioid Consumption	24 hours	Total amount of opioids used
Ambulation as Measured by Distance Walked After Surgery	Post-operative Day 0
Pain as Measure by Numerical Rating Scale (NRS) 11	24 hours	The 11-point numeric rating scale ranges from 0 ("no pain") to 10 ("worst pain imaginable").