Sarcopenia and Postoperative Outcomes Following Total Knee Arthroplasty: A Systematic Review of Observational Studies.

Purpose: Sarcopenia has emerged as a potential prognostic factor for postoperative complications, functional recovery, patient-reported outcomes, and healthcare costs in patients undergoing total knee arthroplasty (TKA). This systematic review aimed to evaluate its impact on these outcomes following primary TKA.

Methods

A systematic review was conducted according to PRISMA guidelines and prospectively registered in PROSPERO (CRD420261320013). PubMed/MEDLINE, EMBASE, and Cochrane Library were searched up to 1 December 2025. Comparative clinical studies including sarcopenic and non-sarcopenic patients undergoing primary TKA and reporting postoperative outcomes were included. Methodological quality was assessed using the MINORS tool. Due to heterogeneity in study design, diagnostic criteria, and outcome measures, a narrative synthesis was performed.

Results

Nine studies including more than 93,000 patients were analyzed. Sarcopenia prevalence ranged from 7.7% to 25%. Sarcopenic patients demonstrated higher rates of postoperative complications, including medical events, blood transfusion, falls, fractures, reoperations, and implant-related complications. Functional recovery was delayed, particularly in patients with sarcopenic obesity, with slower improvements in range of motion and gait speed. Although both groups improved after TKA, short- to mid-term patient-reported outcomes were often inferior in sarcopenic patients, while long-term differences were less consistent. Sarcopenia was also associated with longer hospital stay and increased healthcare costs.

Conclusions

Sarcopenia is associated with worse postoperative outcomes following primary TKA and may represent a modifiable risk factor for perioperative optimization.