Protocol not feasible as written

Patients will be randomized (like the flip of a coin) to receive Exparel and a nerve block, standard of care for this procedure, or Exparel alone for pain management after surgery. They will also be asked to complete questionnaires before surgery, during their stay at the hospital after surgery, then at 3 months, 6 months and 12 months after surgery to assess pain and/or function levels, as well as the amount of pain medicine patients have used after surgery. Patients' leg strength will be measured immediately after surgery and again at 3, 6 and 12 months after surgery.

Inclusion Criteria:

• Male or female, aged 18 to 80 years at the time of surgery.
• Willing and able to give voluntary informed consent to participate in this investigation.
• Candidate for total knee arthroplasty.
• BMI < 35.

Exclusion Criteria:

• Subject has had previous arthroplasty or fracture procedure(s) on the operative knee.
• Creatine level ≥ 1.5
• Pre-existing gait disturbance or neuropathy.
• Allergy to local anesthetics.
• Inflammatory arthropathies.
• Female patient who is pregnant or nursing.
• Chronic use of narcotics
• Any other reason (in the judgment of the investigator).