This is a prospective, randomized clinical trial evaluating three groups. The groups are:

Group 1 (Control): Subjects that receive only the existing standard-of-care multimodal pain management protocol and do not receive post-operative intra-articular catheter.

Group 2 (Investigational Treatment/Intervention): Subjects that receive the brand 1 intra-articular catheter pump with existing standard-of-care multimodal pain management protocol in the immediate post-operative period.

Group 3 (Investigational Treatment/Intervention): Subjects that receive the newer brand 2 intra-articular catheter pump with existing standard-of-care multimodal pain management protocol in the immediate post-operative period.

The purpose of this study is to determine the effects of one of two continuous local infiltration analgesia (intra-articular catheter device) on patient postoperative pain scores following primary unilateral total knee arthroplasty in comparison to no addition of an intra-articular (IART) catheter post total knee arthroplasty (TKA). The investigators hypothesize that if patients undergoing primary unilateral TKA surgery receive an intra-articular catheter device that continuously delivers local infiltration analgesia in the postoperative period, then their postoperative pain scores on the visual analog scale will decrease. Secondary objectives will include determining the role of intraoperative tourniquet use on thigh versus knee postoperative pain and quantifying the amount of additional postoperative patient communication related to the intra-articular catheter device.

Previous literature demonstrates conflicting results on the effects of continuous local infiltration analgesia on postoperative pain management following TKA. The proposed study incorporates a well-designed and substantially powered study to directly compare patient postoperative pain scores with and without the use of an intra-articular catheter device, which will provide additional evidence and clarity to the literature.

If the intra-articular catheter is determined to provide meaningful reductions in postoperative pain, this directly benefits patients undergoing TKA surgery. Decreases in postoperative pain allow for increased patient comfort and earlier functional knee rehabilitation following surgery, both of which promote a faster recovery. A favorable intra-articular catheter study, in addition to the previous literature on continuous local infiltration analgesia, has the potential to change the previous standard of care following TKA surgery to add intra-articular catheter or similar devices as an evidence-based treatment in multimodal pain protocols. If the intra-articular catheter is determined not to provide clinically significant reductions in postoperative pain, then these devices have no substantial benefit to the patient and orthopedic surgeons can stop prescribing them. TKA surgery would become more cost-effective as the additional cost associated with the intra-articular catheter device will no longer be charged. The intraarticular intra-articular catheter patient pump has a rare, but small risk of infection due to the portal from the external environment to the knee joint. This additional catheter infection risk will be eliminated if future use of the intra-articular catheter device subsides.

Inclusion Criteria:

1. Patients undergoing elective outpatient unilateral TKA at Mallard Creek Surgery Center
2. Subjects ≥ 18 years or age
3. Subjects willing and able to provide written informed consent to participate in this study
4. Subjects who are indicated to use an intra-articular catheter pump system

Exclusion Criteria:

1. Subjects < 18 years of age
2. Subjects with history of chronic pain, neuropathic pain, or currently enrolled in pain management agreement
3. Subjects undergoing bilateral TKA
4. Subjects taking opiate pain medication preoperatively within 6 weeks of surgery date.
5. Subjects allergic to any components or treatment medications

No IPD sharing