Saphenous (Adductor Canal) Nerve Block vs. Femoral Nerve Block for Total Knee Arthroplasty: A Novel Approach for Postoperative Analgesia

IRB Number: 2012-031
(trial not enrolling new patients)

Institutional Review Board, Hospital for Special Surgery

December 09, 2010

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Principal Investigator

David H. Kim, MD 


Yi Lin, MD, PhD
Jacques T. YaDeau, MD, PhD
Daniel B. Maalouf, MD, MPH
Enrique A. Goytziolo, MD
Richard L. Kahn, MD
Alejandro Gonzalez Della Valle, MD
Janet Cahill, PT, DPT, CSCS
Charles Fisher, PT
Daniel Yoo


Our study will compare the use of saphenous nerve blocks performed at the adductor canal versus femoral nerve blocks for total knee replacements. We hypothesize that the saphenous nerve block performed at the level of the adductor canal provides adequate pain relief without significantly compromising muscle strength, enabling patients to mobilize early and possibly be discharged earlier to the rehabilitation center.

We will enroll a total of 84 patients (42 patients will receive the saphenous nerve block and 42 will receive the femoral nerve block). Before and after surgery, we will assess motor strength of the operative and nonoperative legs by a neurologic exam (based on a 12 point scale) and by using a hand held dynamometer. Until discharge, we will also record patientsí pain scores, physical therapy progress and satisfaction.

If our study proves the saphenous nerve block to be an effective method of postoperative pain control without compromising quadriceps strength, it would be seen as a better alternative to femoral nerve blocks. 

Inclusion/Exclusion Criteria

Inclusion Criteria

 All patients ages 18-90 undergoing primary unilateral total knee arthroplasty

        Planned use of neuraxial anesthesia

        Ability to follow study protocol

        American Society of Anesthesiology (ASA) Class 1-3

Exclusion Criteria

        Contraindication to a spinal or epidural anesthetic

        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 a pre-existing neuropathy on the operative limb

        Contraindication to a femoral nerve block or saphenous nerve block

        Allergy to any of the study medications

        ASA Class 4-5

        Non-English speaking patients

Contact Information

David Kim, MD