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

Maintaining physiological homeostasis against surgical stress is a critical component of perioperative management. In this study, preoperative functional reserve will be assessed using Handgrip Strength (HGS) as a rapid, non-invasive marker of muscle strength and physical capacity. Quantitative muscle quality and stiffness (in kPa or m/s) will be evaluated via ultrasound Shear Wave Elastography (SWE) of the dominant biceps brachii muscle.

Patient-reported postoperative recovery quality will be measured using the validated Turkish version of the Quality of Recovery-15 score (QoR-15T). Secondary objectives include assessing the correlation between HGS and SWE measurements, evaluating the influence of anesthesia type (general vs. spinal anesthesia) on QoR-15T scores in patients with low functional reserve, and analyzing the association of baseline routine laboratory parameters (e.g., albumin, total protein, CRP, calcium and creatinine) with recovery outcomes. All procedures are observational, non-invasive, and integrated into standard perioperative care without altering routine clinical management.

• Handgrip Strength (HGS) Measurement (Diagnostic test): Isometric handgrip strength measured preoperatively using a hydraulic hand dynamometer on the dominant hand (mean of 3 consecutive measurements in kg).
• Ultrasound Shear Wave Elastography (SWE) (Diagnostic test): Quantitative measurement of biceps brachii muscle stiffness (shear wave elasticity kPa) assessed preoperatively at rest and during contraction using ultrasound shear wave elastography.

Primary outcomes

• Postoperative Quality of Recovery Score (QoR-15T) [Postoperative 24 hours]: Postoperative quality of recovery assessed at the bedside using the validated Turkish version of the Quality of Recovery-15 (QoR-15T) scale. The scale evaluates five dimensions: pain, physical comfort, emotional state, physical independence, and psychological support. Total scores range from 0 to 150, where higher scores represent superior recovery quality.

Secondary outcomes

• Dominant Handgrip Strength (HGS) [Preoperative baseline (Day of surgery, prior to induction)]: Maximum isometric handgrip strength (measured in kilograms) evaluated using a Baseline LITE hydraulic hand dynamometer on the dominant hand. The mean value of three consecutive attempts will be recorded.
• Biceps Brachii Muscle Stiffness Measured by Shear Wave Elastography (SWE) [Preoperative baseline (Day of surgery, prior to induction)]: Quantitative measurement of dominant biceps brachii muscle stiffness (shear wave elasticity in kPa) evaluated using ultrasound shear wave elastography. Three consecutive measurements each will be obtained during muscle relaxation and active contraction, and averaged.
• Comparison of Postoperative QoR-15T Scores by Anesthesia Technique [Postoperative 24 hours]: Comparison of 24-hour postoperative QoR-15T scores between patients receiving general anesthesia versus spinal anesthesia, specifically analyzing the interaction with preoperative functional reserve levels.
• Correlation Between Routine Preoperative Laboratory Biomarkers and Recovery Scores [Preoperative baseline (up to 7 days prior to surgery) and postoperative 24 hours]: Assessment of the correlation between baseline routine laboratory parameters (C-reactive protein, serum albumin, total protein, creatinine, calcium) and 24-hour postoperative QoR-15T recovery scores.

Sex: All, ages: 60 Years to 100 Years

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.

• Derya Ozkan, Prof. MD, Principal investigator, Ankara Etlik City Hospital, Department of Anesthesiology and Reanimation