This study is being done to evaluate the outcomes of patients undergoing total knee replacement with two different methods of local pain control:shots of liposomal bupivacaine, a long acting anesthetic, directly into the knee during surgery or anesthetic delivered continuously to the adductor canal to provide long term pain relief. The goal is to try to find a standard protocol that provides the greatest pain relief for patients undergoing total knee replacement.

Inclusion Criteria:

• Male or non-pregnant female between the ages of 18-65
• Patients willing and able to sign the informed consent
• Patients able to comply with follow-up requirements including self-evaluations
• Patients requiring a primary total knee replacement
• Patients with a diagnosis of osteoarthritis, traumatic arthritis, or avascular necrosis

Exclusion Criteria:

• Revision total knee arthroplasty
• Bilateral total knee arthroplasty
• Patients with inflammatory arthritis
• Patients with a body mass index (BMI) > 40
• Allergy to ropivacaine, bupivacaine, or other local anesthetic agents
• Current use of opioid drugs
• Patients with a history of total or unicompartmental reconstruction of the affected joint
• Patients that have had a high tibial osteotomy or femoral osteotomy
• Patients with neuromuscular or neurosensory deficiency, which would limit the ability to assess pain levels
• Patients with a systemic or metabolic disorder leading to progressive bone deterioration
• Patients that are immunologically compromised, or receiving chronic steroids (>30 days), excluding inhalers
• Patients' bone stock is compromised by disease or infection, which cannot provide adequate support and/or fixation to the prosthesis
• Patients with knee fusion to the affected joint
• Patients with an active or suspected latent infection in or about the knee joint
• Patients that are prisoners