The Negative Impacts of Sarcopenia on Primary Total Knee Arthroplasty under the Enhanced Recovery after Surgery Protocol.

ABSTRACT

OBJECTIVE: Sarcopenia, as an emerging public health concern, has been associated with postoperative adverse outcomes in various surgical procedures. However, the evidence regarding the impacts of sarcopenia on total knee arthroplasty (TKA) remained limited. This study aimed to assess the impacts of sarcopenia on primary TKA based on the enhanced recovery after surgery (ERAS) protocol. METHODS: This retrospective study included 291 patients who received unilateral TKA from October 2017 to May 2018 in our institution. Sarcopenia was diagnosed based on the algorithm of Asian Working Group for Sarcopenia 2019. The handgrip strength was measured using a handheld dynamometer and the muscle mass was estimated by a previously validated anthropometric equation. Patients were classified into sarcopenia group and non-sarcopenia group. The outcomes included complications, postoperative length of stay (LOS), total hospitalization cost, operative time, total estimated blood loss, blood transfusion rate, and the 12-item forgotten joint score (FJS-12) at the follow-up. The propensity score matching (PSM) was used to adjust confounding factors. We compared continuous variables using Student's t-test and the Wilcoxon Mann-Whitney U test for normal and non-normal distributions, respectively, and categorical variables with chi-square tests. RESULTS: Of the 291 patients, 58 (19.9%) patients were identified as having sarcopenia. After PSM, each group matched 42 patients. All matched patients were followed-up at least 5 years. Patients with sarcopenia had higher rates of surgical complications compared to the non-sarcopenia group (p = 0.019), and no significant difference was observed in 30-day readmission, and periprosthetic joint infection. The sarcopenia group had significantly longer LOS (p = 0.038), higher total hospitalization (p = 0.015) than the non-sarcopenia group. For the FJS-12 scores at follow-up, patients with sarcopenia had significantly higher scores than the non-sarcopenia group (p = 0.024). CONCLUSION: Our findings indicated sarcopenia may be a risk factor for postoperative complications, prolonged LOS, increased hospitalization cost and reduced patient satisfaction.