Effect of Micronized Creatine Monohydrate on Muscle Mass, Strength and Performance in Older Adults Submitted to Total Knee Arthroplasty

Inclusion Criteria: * Persons 65 years of age or older who have been operated on for the first time for total knee arthroplasty, * who are undergoing an outpatient rehabilitation program according to standard clinical practice, * who sign the informed consent form. Exclusion Criteria: * Chronic renal disease at stage G3b or higher or glomerular filtration rate \<30 ml/min/1.73m2. * Hepatic insufficiency, cirrhosis. * Neuromuscular and neurodegenerative diseases (amyotrophic lateral sclerosis, multiple sclerosis, muscular dystrophy, myasthenia gravis, Parkinson's disease, etc.). * Severe or very severe chronic obstructive pulmonary disease (COPD) (GOLD III-IV). * Moderate or severe chronic heart failure (NYHA 3-4). * Central sensitivity syndrome (fibromyalgia and chronic fatigue syndrome). * Moderate or severe cognitive impairment (GDS≥4). * Moderate-severe dependence for basic activities of daily living (preintervention Barthel index \<60 points). * Hemiparesis, amputation or malformation of any limb. * Consumption of creatine monohydrate supplements in the last 6 months.