Local Infiltration Analgesia Following Total Knee Arthroplasty (RAK-total)

Local Infiltration Analgesia With Ropivacaine, Ketorolac and Epinephrine Intra- and Postoperatively in Total Knee Arthroplasty

The primary aim of this study is to evaluate if intra- and postoperative administration of ropivacaine, ketorolac and epinephrine into the operating field would affect morphine consumption. Secondary end-points are hospital stay, pain intensity and side effects. In an attempt to assess the safety of this technique, knee function and patient satisfaction scores are assessed up to 3 months after surgery.

Postoperative pain is often severe following knee arthroplasty. Recently, a local infiltration analgesia (LIA) technique was developed by Drs Kerr and Kohan in Sydney, Australia. With this LIA-technique, a long-acting local anesthetic (ropivacaine), a nonsteroidal anti-inflammatory drug (ketorolac), and epinephrine are infiltrated intraoperatively and via an intraarticular catheter postoperatively. We ahve completed a study on unicompartmental knee arthroplasty and the present study is investigating total knee arthroplasties. The primary aim of this study is to evaluate if intra- and postoperative administration of ropivacaine, ketorolac and epinephrine into the operating field would affect morphine consumption. Secondary end-points are hospital stay, pain intensity and side effects. In an attempt to assess the safety of this technique, knee function and patient satisfaction scores are assessed up to 3 months after surgery.

In Group A, 400 mg ropivicaine, 30 mg ketorolac and 0.5 mg epinephrine (total volume 166 ml) are infiltrated by the surgeon into the soft tissues peri-articularly during the operation in the following way: Before inserting the components, 20-30 ml are injected into the posterior capsule and before closure of the wound the rest is injected into the capsule incision, the synovium, the ligament and the subcutaneous tissue. After 21 postoperative hours in Group A, 200 mg ropivicaine, 30 mg ketorolac and 0.1 mg epinephrine, total volume 22 ml, are injected intraarticularly via the catheter.

In Group P (placebo) no injections were given intraoperatively. All patients had a tunnelled intra-articular multihole 20-G catheter placed at the end of the operation by the surgeon.After 21 postoperative hours 22 ml of saline was injected intraarticularly via the catheter.

Inclusion Criteria: Patients scheduled for total knee arthroplasty Aged 20-85 yrs ASA physical status I-III and mobility indicating normal postoperative mobilization Exclusion Criteria: Known allergy or intolerance to one of the study drugs Serious liver-, heart- or renal decease Rheumatoid arthritis Chronic pain or bleeding disorder