Preoperative Muscle Stiffness, Functional Reserve, and Postoperative Quality of Recovery in Lower Extremity Arthroplasty

In elderly patients undergoing arthroplasty surgery, postoperative recovery quality is closely related to preoperative physical reserve. Sarcopenia and reduced muscle quality can increase postoperative complications. This prospective observational study aims to investigate whether preoperative Handgrip Strength (HGS) and muscle stiffness measured by Shear Wave Elastography (SWE) can predict the quality of recovery at postoperative 24 hours (assessed via the Quality of Recovery-15 \[QoR-15T\] score) in patients aged 60 and older undergoing elective total knee or hip arthroplasty.

Inclusion Criteria: * Patients aged 60 years and older. * Scheduled for elective unilateral total knee arthroplasty (TKA) or total hip arthroplasty (THA). * American Society of Anesthesiologists (ASA) Physical Status classification I, II, or III. * Six-Item Screener (SIS) score \> 4 (indicating preserved baseline cognitive status). * Voluntary participation with signed written informed consent. Exclusion Criteria: * History of upper extremity surgery, trauma, or pathology precluding handgrip or biceps brachii measurement. * ASA Physical Status classification IV or V. * Emergency surgical procedures. * Significant baseline cognitive impairment (Six-Item Screener \[SIS\] score ≤ 4). * Refusal to provide consent or withdrawal from the study.