The Effects of a Tourniquet in Total Knee Arthroplasty.

The Effects of a Tourniquet on Implant Migration and Muscle Strength and Function in Patients Operated With Total Knee Arthroplasty

Zimmer Biomet, University of British Columbia, Karolinska University Hospital, St Olavs Hospital University Hospital in Trondheim, Kristiansund Hospital

About 5000 total knee arthroplasties (TKA) are performed annually in Norway. Pain and reduced physical function is present in patients operated with TKA up to a year after surgery and about one of five patients are not satisfied with the outcome from TKA surgery. The use of tourniquet during surgery may also have impact on pain and physical function. Whether TKA surgery should be performed with or without the use of tourniquet, is a much-debated issue in orthopedic surgery today, and there is still no consensus in this field. This study will investigate early muscle strength and power recovery, neuromuscular recordings, neuronal changes and patient reported outcome measures after surgery with tourniquet versus not tourniquet.The findings in this study are expected to have implications for rehabilitation and the outcome of the TKA surgery.

In the patients randomized to the use of tourniquet, the tourniquet time starts before skin incision and terminates when the wound closure starts. The cuff pressure is set at 300mmHg.

EMG recordings are made using 10mm electrodes (Ag-AgCl) attached in a bipolar configuration over the vastus lateralis and rectus femoris

Change from 1) preoperative (baseline) to day 2 postoperative, 2) change from preoperative to 8 weeks postoperative, 3) change from preoperative to 1 year postoperative

The stair climbing test measures the time (in seconds) to ascend, turn around and descend a regular stairway of 11 steps. The patients are asked to perform the test as quickly as possible.

Change from 1) preoperative (baseline) to 2) change from preoperative to 8 weeks postoperative, 3) change from preoperative to 1 year postoperative

1RM leg strength is measured using a leg press ergometer with the participant in a supine position (Steens Physical; Ring Mekanikk, Moelv, Norway)

Change from 1) preoperative (baseline) to day 2 postoperative, 2) change from preoperative to 8 weeks postoperative, 3) change from preoperative to 1 year postoperative

1RM knee extension is measured using a knee extension equipment (Body-Solid, Forest Park, IL, USA) with the participant in a seated position.

Change from 1) preoperative (baseline) to day 2 postoperative, 2) change from preoperative to 8 weeks postoperative, 3) change from preoperative to 1 year postoperative

Change from 1) preoperative (baseline) to day 2 postoperative, 2) change from preoperative to 8 weeks postoperative, 3) change from preoperative to 1 year postoperative

Evaluating pain. The scale range from 0 (no pain) to 10 (worst pain imaginable) (7). The patients are asked to write down NRS values both at rest and during activity each day for the first 4 weeks postoperatively in a home log.

Gene expression analyses. RT-PCR for expression levels for VEGF, NGF, SP, CGRP, IL-6, IL-1, TNF-alpha, Bad, Bax, Bid, Bim, Fas, Fas-ligand, Bcl-2, Mcl, and FLIP. Results will be normalized to GAPDH expression levels.

Inclusion Criteria: Knee osteoarthrosis qualifying for total knee arthroplasty Exclusion Criteria: Coagulation disease Rheumatoid arthritis Peripheral vascular disease Malign disease Pregnancy On-going infection Not able to understand written and oral information in Norwegian