Postoperative quadriceps muscle strength was lowered after tourniquet application during total knee arthroplasty (TKA). Furthermore, tourniquet application results in higher proteolytic activity within vastus medialis cells, without influence on the amount and function of mitochondria. The effects of the commonly utilized intraoperative tourniquet on gene expression within the human skeletal muscle cells are barely examined. The purpose of the present study was to analyze the gene expression within the skeletal muscle cells after tourniquet-induced ischemia to identify differential expressed genes (DEGs) and pathways.
As part of a randomized, controlled, monocentric trial (Clinical-Trials.gov NCT02475603) 20 patients, scheduled to undergo primary total knee arthroplasty (TKA), were included. Written informed consent was received and the patients were randomly assigned to Group A (TKA with tourniquet) (n = 10) and Group B (TKA without tourniquet) (n = 10). A muscle biopsie of (5 × 5 × 5 mm) 125 mm
Tourniquet application resulted in a total of 3555 (13.8%) statistically significant DEGs within vastus medialis cells. 76 DEGs (29 upregulated, 47 downregulated) revealed a relative difference of more than 25%. Statistically significant changes occurred in 59 (25.8%) of 229 analyzed pathways. Furthermore, there was no clinically meaningful difference between the groups with regard to CRP and WBC count.
These findings add further knowledge and should raise the awareness of surgeons about the effects of tourniquet induced ischemia at the gene expression level. Additional high-quality research may be warranted to examine the short and long term clinical significance of the present data.
Level I.
Tourniquet induced ischemia results in significant changes of the gene expression within cells of vastus medialis including metabolism, genetic information processing and cellular processes. The identified altered expression of genes and pathways might serve as pharmacotherapeutical targets; although further research is needed to clarify the underlying biological processes.