Minimal Versus Conventional Exposure in Unicompartmental Knee Arthroplasty

The purpose of this study is to determine whether Minimal Invasive Surgery results in less postoperative pain and better mobilization than conventional technique in Unicompartmental Knee Arthroplasty, provided that both groups receive Local Infiltration Analgesia.

Postoperative pain is often moderate to severe following unicompartmental knee arthroplasty. In order to reduce postoperative pain and improve mobilization the minimal invasive technique was developed. After a 8-10 cm skin incision, a medial parapatellar capsule incision in made. The rectus tendon or the vastus medialis are not incised and the patella is not everted. In recent years The Local Infiltration Analgesia (LIA) technique has been developed to reduce postoperative pain. 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. The aim of this study is to investigate if Minimal Invasive Surgery results in less postoperative pain and better mobilization than conventional technique in Unicompartmental Knee Arthroplasty, provided that both groups receive Local Infiltration Analgesia.

Unicompartmental knee arthroplasty, Surgical exposure, Minimal invasive surgery, Local Infiltration Analgesia, Knee Arthroplasty

After a 8-10 cm skin incision, a medial parapatellar capsule incision is made. The vastus medialis muscle or the rectus tendon are not incised, nor is the patella everted. The patella is merely pushed slightly aside when the bone cuts are made and the prostheses are cemented in place. Local Infiltration Analgesia is used.

After a 15-20 cm midline skin incision is made, a medial parapatellar capsule incision is made. The incision is carried up through the insertion of the vastus medialis and into the rectus tendon. The patella is everted. The bone cuts are made and the prostheses are cemented in place. Local Infiltration Analgesia is used.

Inclusion Criteria: Patients scheduled for unicompartmental knee arthroplasty Aged 20-80 yrs ASA physical status I-III and mobility indicating normal postoperative mobilization Exclusion Criteria: Known allergy or intolerance to local anesthetics, ASA or NSAID Serious liver-, heart- or renal decease Rheumatoid arthritis Chronic pain or bleeding disorder

Essving P, Axelsson K, Otterborg L, Spannar H, Gupta A, Magnuson A, Lundin A. Minimally invasive surgery did not improve outcome compared to conventional surgery following unicompartmental knee arthroplasty using local infiltration analgesia: a randomized controlled trial with 40 patients. Acta Orthop. 2012 Dec;83(6):634-41. doi: 10.3109/17453674.2012.736169. Epub 2012 Oct 8.