Total knee arthroplasty (TKA) is the most common and cost-effective treatment for older adults with long-standing
osteoarthritis. Projections indicate that nearly 3.5 million older adults will undergo this procedure annually by the year 2030. Thus, understanding the factors that lead to optimal outcomes is of great clinical interest. In the majority of cases,
tourniquet is applied during surgery to maintain a clear surgical field, however, there is debate as to whether this intervention is completely benign. In particular,
muscle atrophy is a significant factor in preventing full functional recovery following surgery, and some evidence suggests that
tourniquet application and the associated
ischemia-reperfusion injury that results contributes to
muscle atrophy. For this reason, we examined tissue level changes in muscle in TKA patients following surgery and found that there was a significant increase in cross-sectional area of muscle fibers of all types. Furthermore, to detect changes not evident at the tissue level, we performed NextSeq analysis to assess the transcriptional landscape of quadriceps muscle cells following TKA with
tourniquet and found 72 genes that were significantly upregulated. A large proportion of those genes regulate cell stress pathways, suggesting that muscle cells in our cohort of older adults were capable of mounting a significant response to cell stress. Furthermore, factors related to
complement were upregulated, suggesting
tourniquet may play a role in priming cells to
ischemia reperfusion injury. Therefore, our analysis reveals potential harms of
tourniquet during TKA, thus suggesting that surgeons should consider limiting its use.