Saphenous Nerve Block vs. Femoral Nerve Block for Total Knee Arthroplasty

Hospital for Special Surgery (HSS)

Status

Completed

Conditions

Difference Between Femoral Nerve Block and Saphenous Block

Treatments

Procedure: Control Technique

Procedure: Study Technique

Study type

Interventional

Funder types

Other

Identifiers

NCT01505374

2012-033

Details and patient eligibility

About

Currently, the regional anesthetic standard of care for total knee replacement surgery is combined spinal/epidural to provide long-lasting pain relief with or without a femoral nerve block (FNB). The femoral nerve block refers to a technique that your anesthesiologist can use to numb the thigh muscle for approximately 18 hours after surgery. While this technique offers significant pain relief, it is possible it may cause muscle weakness and increase patients' recovery times. Hence there is a need for an alterative anesthetic technique, one that may help minimize postoperative pain as effectively as a femoral nerve block, while not causing weakness of the thigh muscle.

The saphenous nerve, a branch of the femoral nerve, provides sensation to the knee. Thus it is hypothesized by "blocking" or anesthetizing the saphenous nerve with local anesthetic closer to where it branches off, the area around and below the knee will feel numb. Yet unlike the femoral nerve block, the thigh muscle itself will still be able to function.

For patients undergoing two total knee replacements at one time or bilateral total knee replacement, they will be randomly assigned to receive a femoral nerve block on one leg and a saphenous block on the other. Pain levels will be measured and thigh muscle strength will be tested using a dynamometer before surgery, 6-8 hours following anesthesia administration, and on postoperative days 1 and 2.

Enrollment

60 patients

Sex

All

Ages

40 to 80 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

All patients ages 40-80 undergoing Bilateral Total Knee Replacement
Planned use of neuraxial anesthesia
Ability to follow study protocol

Exclusion criteria

Contraindication to a spinal or epidural anesthestic
Not a candidate for bilateral total knee replacement
Chronic opioid use (defined as daily or almost daily use of opioids for >3 months)
Hypersensitivity and/or allergy to local anesthetics
Intraoperative use of any volatile anesthetic
Patients with pre-existing neuropathy on the operative limb
Contraindication to femoral nerve block or saphenous nerve block
Allergy to any of the study medications
American Society of Anesthesiologists (ASA) Class 4-5
Non-English speaking patients