Recognizing Sarcopenia in Total Knee Arthroplasty Patients: A Call for Greater Awareness.

Abstract

Suspected sarcopenia, characterized by early signs of muscle weakness and functional decline, is a growing concern in elderly populations and may adversely affect outcomes of total knee arthroplasty (TKA). While formal diagnostic confirmation may not always be feasible in clinical practice, early recognition using simple screening tools such as the Strength, Assistance with walking, Rising from a chair, Climbing stairs, and Falls (SARC-F) questionnaire and functional performance tests can help identify at-risk patients and may provide valuable prognostic information to improve postoperative outcomes. This retrospective study included 97 patients (10 men, 87 women; mean age: 66 years) who underwent unilateral TKA between 2018 and 2023. Sarcopenia was assessed using the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) algorithm. All patients completed the SARC-F and Sarcopenia Quality-of-Life (SarQoL), Oxford, and Knee Society Score (KSS), as well as pre- and postoperative Visual Analog Scale (VAS) scores. Handgrip strength, gait speed, and appendicular skeletal muscle mass (ASM)/height² (measured by bioelectrical impedance analysis) were evaluated. Patients were grouped according to the presence or absence of suspected sarcopenia based on the SARC-F questionnaire. Suspected sarcopenia was present in 34 patients (35.1%), while 63 patients (64.9%) had no suspicion. Probable sarcopenia based on handgrip strength was identified in eight patients, whereas no patient met the muscle mass cutoff for confirmed sarcopenia. Patients who had suspected sarcopenia were older (P = 0.05), had higher postoperative VAS scores (P = 0.05), and more frequently fell below handgrip cutoff values (P = 0.03). Gait speed was significantly slower in this group (P < 0.01). They also demonstrated lower Oxford scores (P < 0.01) and a trend toward lower KSS scores (P = 0.07). Postoperative walking aid requirement (P = 0.03) and comorbidity rates (P = 0.04) were significantly higher in patients who had suspected sarcopenia. Patients who had suspected sarcopenia exhibited poorer functional outcomes following TKA, even in the absence of reduced muscle mass on bioimpedance analysis. The SARC-F questionnaire, as a simple and practical tool, may provide early recognition of patients at risk and guide interventions to improve postoperative satisfaction and recovery. Larger prospective studies are warranted to validate these findings.