Enhanced Recovery After Major Surgery and Chronic Pain for Total Knee Arthroplasty

The goal of this interventional clinical trial is to assess opioid consumption 24-48 hrs post anesthesia block among patients undergoing total knee arthroplasty. The main question it aims to answer is:

1. Is there a difference in opioid consumption 24-48 hours post block administration among patients that receive an adductor canal catheter (ACC) versus adductor canal block (ACB)?

Participants will be:

* Randomized to receive an adductor canal catheter (ACC) or a sham adductor canal catheter.
* Asked to use the Diagnotes application to communicate with the pain doctor while the catheter is in place.
* Follow up for up to 6 months post-operation. Researchers will compare the interventional group (ACC) to the control group (sham ACC + ACB) to see if there is difference in opioid consumption and chronic pain at 6 months post-operation.

The purpose of this study is to see if adding a continuous ACB catheter will extend analgesia beyond the 24-48 hour period. This interventional clinical trial will assess opioid consumption in patients undergoing total knee arthroplasty 24 to 48 hours after anesthesia block. Rebound pain is a well-known phenomenon in which patients experience severe pain immediately after the nerve block is removed. It is also known that by extending the duration of analgesia, you can reduce or prevent rebound pain. Motor sparing compartment blocks have transformed patients' ability to participate in rehabilitation earlier than ever before, even ambulating on POD 0. Thus, by extending analgesia and encouraging early ambulation, adductor canal catheters are likely to not only reduce opioid consumption but also allow for earlier discharge. The two "hot" themes in recent total knee replacement analgesia pathways are not only providing an effective Enhanced recovery after surgery (ERAD) protocol, but also combating the opioid epidemic through regional anesthesia and non-opioid multimodal pathways. This study will assist in determining which modality is superior (single shot blocks with additive versus catheter) and will introduce a novel method of following patients at home via a transitional pain service (telemedicine). This research will further investigate chronic pain 6 months after surgery.

Patients in the intervention group will have a catheter that continuously infuses numbing medication into their operative leg for 50 hours (up to POD 3). It is hypothesized that the patient will have better pain control, mobility, and less rebound pain, which is common following POD 1. By infusing the catheter with a disposable single use ambIT system (Summit Medical Products), all patients enrolled in the intervention group (ACC) will have the same amount running continuously, allowing the patient to be discharged with the catheter in place before the 50-hour infusion is completed. Prior to discharge, patients will be instructed on how to remove the catheter and will be able to download the Smartphone app "Diagnotes" at the hospital. While the catheter is in place, the Diagnotes app (a HIPPA-compliant text messaging service) will be the patient's primary means of communication with the pain doctor at home.

Patients in the control group will have a sham (fake) catheter attached to their operative leg for 50 hours. Patients will also be instructed on how to remove the catheter prior to discharge and will be able to download the Smartphone app "Diagnotes" in the hospital. While the catheter is in place, the Diagnotes app (a HIPPA-compliant text messaging service) will be the patient's primary means of communication with the pain doctor at home.

Researchers will contact both groups for follow-ups for up to 6 months.

Eligibility Criteria:
Inclusion Criteria:

* Patients with osteoarthritis scheduled for a primary total knee arthroplasty with a participating surgeon
* Age 18 to 75 years
* Planned use of regional anesthesia
* Ability to follow study protocol
* English speaking (secondary outcomes include questionnaires validated in English only)
* Patients of participating surgeons: Drs. Mayman, Jerabek, Westrich, Su, Della Valle, Alexiades
* Lives within one hour of the hospital
* Has a smartphone

Exclusion Criteria:

* Hepatic or renal insufficiency
* Younger than 18 years old and older than 65
* Patients undergoing general anesthesia
* Allergy or intolerance to one of the study medications
* BMI \> 40
* Diabetes
* ASA of III,IV
* Chronic gabapentin/pregabalin use (regular use for longer than 3 months)
* PCS \> 30
* Chronic opioid use (taking opioids for longer than 3 months, or daily oral morphine equivalent of \>5mg/day for one month)
* Patients with severe valgus deformity or flexion contracture
* Patients unable to follow home catheter instructions and unwilling to go home with an infusing catheter
* Patients who have no home caregivers in the event if a catheter is to be sent home with the patient
* Patients with planned stay at rehab facility