Genicular Nerve Block for Total Knee Arthroplasty

Part of the way in which pain is controlled during total knee replacement surgery is through
a nerve block. The investigators have developed an effective protocol for pain control after
knee replacement, but know that many patients still experience pain around the knee after
knee replacement. There are nerves around the knee that carry pain impulses from behind the
knee. The investigators believe that placing numbing medicine around these nerves can help
with pain in front of the knee after surgery, in addition to the standard nerve block placed
for knee replacement surgery. This may result in taking less pain medication by mouth,and
having less pain with movement. For this study, before the operation, either a placebo
solution or the local anesthetic bupivacaine (a numbing solution) will be placed at three
sites around the knee where these nerves reside. The investigators will evaluate how
participants feel in recovery after surgery, during the stay in the hospital, and call at
home one week after surgery. Knowing if numbing these nerves helps with pain after surgery
will help us further refine our postoperative care plan for patients.

Inclusion Criteria:

- Subjects scheduled for primary elective total knee arthroplasty

- American Society of Anesthesiologists Physical Status I-III

- BMI 18-40 kg/m2

Exclusion Criteria:

- Inability to cooperate with protocol

- Inability to understand or speak English

- Allergy to ropivacaine, bupivacaine or other local anesthetic

- Contraindication to peripheral nerve block (e.g. local infection, neurologic deficit
or disorder, previous trauma or surgery to ipsilateral knee, etc.)

- Revision knee surgery

- Chronic opioid consumption (daily morphine equivalent of >30 mg for at least four
weeks prior to surgery)

- History of chronic pain

- History of psychiatric disorder

- History of diabetes mellitus