Postoperative Pain Control Results Using Periarticular Versus Intra-capsular Injection of Bupivacaine Liposome Injectable Suspension in Total Knee Arthroplasty

The purpose of this study is to determine quantitative and qualitative differences in post-operative pain relief for patients undergoing primary total knee arthroplasty (TKA) who receive administration of a newly approved, long acting local anesthetic branded as ExparelTM (bupivacaine liposome injectable suspension) introduced by one of two different administration methods.

Group 1 would receive a predetermined and standardized dose of ExparelTM introduced directly into the joint capsule at the conclusion of the surgery, effectively bathing the joint in anesthetic solution.

Group 2 would receive the same predetermined and standardized dose of ExparelTM as a local infiltration anesthetic (LIA) by injecting it into the periarticular tissues in nine (9) standard sites at the conclusion of the surgery.

This study is being done to determine if a difference exists between two methods of intraoperative (during surgery) administration of a long-acting local anesthetic (pain relief).

Local pain relief medications are accepted as standard of care as a part of a comprehensive plan for pain relief following a total knee replacement (arthroplasty) (TKA). We expect that the addition of ExparelTM to the usual post-surgery pain control medicines and procedures will result in less need for additional pain medication. It is possible that local injection into the tissue around the total knee replacement joint (periarticular tissues) may provide more effective pain relief than injection directly into the joint (intracapsular) itself, or vice versa. It is also possible that pain relief with either method is approximately equivalent. On the day of surgery, each patient will undergo total knee arthroplasty and cared for utilizing the standard protocol for all patients that undergo total knee arthroplasty at Broward Health Medical Center.

Patients in Group 1 will receive the same amount of ExparelTM injected intracapsularly. Those in is Group 2 will receive a standardized medication regimen including ExparelTM by local infiltration into the periarticular tissues at the conclusion of their TKA procedure. Study participants will undergo injection in this manner until the conclusion of the study.

All subjects will be provided the same methods of postoperative pain control following their TKA surgery as those patients not enrolled in the study.

Eligibility Criteria:
Inclusion Criteria:

* Patients must be over the age of 18
* Patients must have a preoperative diagnosis of osteoarthritis of the knee requiring total knee arthroplasty

Exclusion Criteria:

* Allergy to ExparelTM or certain other local anesthetic agents
* Pregnant females or females who think they may become pregnant
* Markedly abnormal kidney function or renal disease
* History of substance abuse
* History of chronic pain requiring medication
* Had a previous total knee arthroplasty on the same knee which is being replaced (revision total knee arthroplasty)
* Had a previous partial knee arthroplasty, such as a unicompartmental knee arthroplasty on the same knee (also a revision total knee arthroplasty)