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

Efficacy of Supplementation With Micronized Creatine Monohydrate in the Recovery of Muscle Mass, Muscle Strength and Functional Capacity in Older Adults Operated on for Total Knee Arthroplasty: Randomized Clinical Trial

Double-blind randomized placebo-controlled clinical trial with two parallel arms. The main objective is to evaluate the efficacy and safety of creatine supplementation in older adults who have been operated on for total knee arthroplasty and undergoing a usual rehabilitation program. The intervention will consist of daily creatine monohydrate supplementation for 12 weeks. The intervention will start after surgery with a loading dose of 20g/day for 1 week and then continue with a maintenance dose of 5g/day for 11 weeks.

Main outcome mesures included muscle mass, muscle strenght, sarcopenia, frailty, functional capacity and physical performance and will be assessed at baseline, 3 and 6 months follow-up.

Study Overview

• Status: Recruiting
• Conditions: Functional Capacity; Physical Performance; Arthroplasties, Knee Replacement; Sarcopenia in Elderly; Creatine Supplementation; Frailty at Older Adults
• Intervention / Treatment: Dietary supplement: Creatine Monohydrate; Other: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 262
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jéssica Martínez Rodríguez; Phone Number: 2282 0034 937417700; Email: jmartinezro@csdm.cat

Study Locations

• Spain
  • Barcelona
    • Mataró, Barcelona, Spain, 08304
      • Recruiting
      • Elisabet Palomera

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CREATINE; The intervention will consist of daily supplementation with micronized creatine monohydrate for 12 weeks. The intervention will start at the time of hospital discharge with a loading dose of 20g/day for 1 week. Subsequently, a maintenance dose of 5g/day will be continued for 11 weeks.	Dietary supplement: Creatine Monohydrate; The intervention will consist of daily supplementation with micronized creatine monohydrate (FullGas Sport Creatine 200 mesh) for 12 weeks. The intervention will start at the time of hospital discharge with a loading dose of 20g/day for 1 week, divided into 4 intakes of 5g to favor digestive tolerance (breakfast, lunch, snack and dinner). Subsequently, a maintenance dose of 5g/day will be continued for 11 weeks (breakfast). Creatine should be consumed with food to improve its absorption.
Placebo Comparator: PLACEBO; The control group will follow the same rehabilitation regimen as the intervention group and will receive a placebo. It will start at the time of hospital discharge with a loading dose of 20g/day for 1 week. Subsequently, a maintenance dose of 5g/day will be continued for 11 weeks.	Other: Placebo; The control group will follow the same rehabilitation regimen as the intervention group and will receive a placebo with FullGas Sport microcrystalline cellulose. Its physical and organoleptic characteristics are the same as micronized creatine monohydrate. The dosage will be the same as that indicated for the study intervention: it will start at the time of hospital discharge with a loading dose of 20g/day for 1 week, divided into 4 intakes of 5g to favor digestive tolerance (breakfast, lunch, snack and dinner). Subsequently, a maintenance dose of 5g/day will be continued for 11 weeks (breakfast).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in muscle mass	Mesured by Bioimpedance Analysis	Baseline, 3 and 6 months follow-up
Change in Muscle Strenght	Handgrip mesured by Jamar Dynamometer	Baseline, 3 and 6 months follow-up
Change in the prevalence of Sarcopenia	Mesured by EWGSOP2 criteria	Baseline, 3 and 6 months follow-up
Change in Functional Capacity	Mesured by Barthel score	Baseline, 3 and 6 months follow-up
Changes in Performance	Mesured by Timed Up and Go Test (seconds)	Baseline, 3 and 6 months follow-up
Changes in Physical Performance	Mesured by Short Physical Performance Batery (SPPB)	Baseline, 3 and 6 months follow-up
Changes in aerobic capacity	Mesured by 6 minutes Walking Test (meters)	Baseline, 3 and 6 months follow-up
Changes in Walking Speed	Mesured by Gaid Speed	Baseline, 3 and 6 months follow-up
Number of Advers Health Events	Register of advers health events	Baseline, 3 and 6 months follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Frailty status	Mesured by Linda Fried criteria (0 positive criteria: robust, 1-2: pre-frail positive criteria, 3 or more positive criteria: frail)	Baseline, 3 and 6 months follow-up
Arthroscopy complications		Baseline, 3 and 6 months follow-up

Collaborators and Investigators

• Sponsor: Consorci Sanitari del Maresme
• Collaborators: Fundació Privada Salut del Consorci Sanitari del Maresme
• Investigators: Principal Investigator: Jéssica Martínez Rodríguez, Consorci Sanitari Del Maresme; Study Director: Mateu Serra-Prat, PhD, Consorci Sanitari Del Maresme

Study record dates

Study Major Dates

• Study Start (Actual): June 10, 2025
• Primary Completion (Estimated): May 31, 2027
• Study Completion (Estimated): October 31, 2027

Study Registration Dates

• First Submitted: March 27, 2025
• First Submitted That Met QC Criteria: April 11, 2025
• First Posted (Actual): April 13, 2025

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 25, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neuromuscular Manifestations; Pathologic Processes; Pathological Conditions, Anatomical; Muscular Atrophy; Atrophy; Frailty; Sarcopenia; Amino Acids, Peptides, and Proteins; Organic Chemicals; Amino Acids; Guanidines; Amidines; Creatine
• Other Study ID Numbers: CEIm CSdM 24/25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No