Conditions: Total Knee Arthroplasty
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 165
Healthy volunteers: yes

Brief summary:
The purpose of this study is to find a better way to make patients comfortable after their knee surgery. The investigators compared three ways of providing pain relief, either by use of a nerve block at the femoral and sciatic nerve areas, or with actual injections in the surgical joint area with one of two different medicines, either ropivacaine or liposomal bupivacaine (Exparel®). The hypothesis was that the nerve block at the femoral and sciatic nerve areas would result in lower pain scores and opioid consumption than either of the two injections in the surgical joint area.

Detailed description:

Arms:
arm 1: This group received a continuous femoral nerve block and a single injection sciatic nerve block consisting of the following: Peripheral nerve blocks with Bupivacaine. arm 2: This group received intra articular injection with Ropivacaine, a total volume of 120 milliliters (mL) injected in the periarticular structures by the surgeon. Following the current, standardized practice for periarticular infiltration, approximately 30 - 40 mL of solution was injected into the posterior capsule just prior to cementing the implants in place and 40 - 50 mL of solution injected into the medial and lateral retinaculum while the cement was hardening and prior to deflation of the tourniquet. The remaining volume of approximately 40 mL was injected into the quadriceps tendon and subcutaneous tissue prior to skin closure. arm 3: This group received Intra articular injection with liposomal bupivacaine, a total volume of 120 milliliters (mL) injected in the periarticular structures by the surgeon. Following the current, standardized practice for periarticular infiltration, approximately 30 - 40 mL of solution was injected into the posterior capsule just prior to cementing the implants in place and 40 - 50 mL of solution injected into the medial and lateral retinaculum while the cement was hardening and prior to deflation of the tourniquet. The remaining volume of approximately 40 mL was injected into the quadriceps tendon and subcutaneous tissue prior to skin closure.

Interventions: intervention 1: Peripheral nerve blocks with Bupivacaine intervention 2: Intra articular injection with Ropivacaine intervention 3: Intra articular injection with liposomal bupivacaine
Intervention descriptions: intervention 1: Subjects received Bupivacaine 0.5% preoperatively, then Bupivacaine 0.2% upon post anesthesia care unit (PACU) arrival via femoral nerve block, then Bupivacaine 0.25% via single-injection sciatic nerve. intervention 2: Subjects received an intra articular injection with Ropivacaine, a total volume of 120 milliliters (mL) injected in the periarticular structures by the surgeon. Ropivacaine dose depended upon body weight: 50-74.9 kg: 200 mg, 75-99.9 kg: 300 mg, 100-125 kg: 400 mg. intervention 3: Subjects received an intra articular injection with liposomal bupivacaine, a total volume of 120 mL injected in the periarticular structures by the surgeon. Patients weighing 50-125 kg received 266mg of Liposomal Bupivacaine.

Protocol document: