Muscle Regrowth During Physical Rehabilitation and Amino Acid Supplementation
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ClinicalTrials.gov Identifier: NCT00760383 |
Recruitment Status :
Completed
First Posted : September 26, 2008
Results First Posted : December 4, 2014
Last Update Posted : December 4, 2014
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The general hypothesis is that in older adults muscle regrowth after an acute musculoskeletal stress will be positively influenced by traditional physical rehabilitation, and further enhanced by nutritional supplementation. Using state-of-the-art stable isotope methodologies for the study of muscle metabolism and methodologies for the measurement of cell signaling, we will test the following specific hypotheses: 1) Total knee arthroplasty (TKA) induces an acute net protein catabolism mainly by reducing muscle protein synthesis; 2) TKA induced catabolism is attenuated by the ingestion of essential amino acids (EAA); 3) EAA supplementation in combination with physical therapy (PT) will stimulate muscle protein synthesis and mTOR signaling to a greater extent than PT with Placebo; and 4) EAA supplementation during TKA PT rehabilitation will improve muscle strength, muscle volume and functional outcomes to a greater extent than PT with Placebo.
Public Benefit: This research will focus rehabilitation efforts on specific and currently unresolved mechanisms responsible for muscle loss following total knee replacement in older adults. While knee pain due to bone arthritis is often alleviated after knee replacement, complete return of physical function and independence is difficult to achieve. This research will help to restore physical function and independence in the rapidly growing population of older adults with knee arthritis.
Condition or disease | Intervention/treatment | Phase |
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Osteoarthritis | Dietary Supplement: Essential amino acids Dietary Supplement: Alanine | Not Applicable |

Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 60 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Treatment |
Official Title: | Muscle Regrowth During Physical Rehabilitation and Amino Acid Supplementation |
Study Start Date : | June 2008 |
Actual Primary Completion Date : | December 2013 |
Actual Study Completion Date : | December 2013 |

Arm | Intervention/treatment |
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Experimental: EAA+PT
20 g EAA daily for 7 days prior to TKA surgery and for 14 days after surgery.
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Dietary Supplement: Essential amino acids
Subjects will ingest 20 grams of essential amino acids (EAA) daily for 7 days prior to total knee arthroplasty (TKA) surgery and for 14 days after surgery daily. On the days they are seen by physical therapy (PT) they will ingest the EAA supplement 30 minutes after the end of each PT rehabilitation session.
Other Names:
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Placebo Comparator: ALA+PT
20 g NEAA daily for 7 days prior to TKA surgery and for 14 days after surgery.
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Dietary Supplement: Alanine
Subjects will ingest 20 grams of non-essential amino acid (NEAA) daily for 7 days prior to total knee arthroplasty (TKA) surgery and for 14 days after surgery daily. On the days they are seen by physical therapy (PT) they will ingest the NEAA supplement 30 minutes after the end of each PT rehabilitation session. |
- Stair Time up [ Time Frame: 6 weeks ]
- Quadriceps Muscle Strength [ Time Frame: 6 weeks ]
- Mid-thigh Muscle Volume [ Time Frame: 6 weeks ]Analysis was performed using the Analyze 11 software package with semi-automated delineation of quadriceps, hamstrings, and adductors boarders. Using thresholding methods, the software can differentiate operator-delineated parameters set to distinguish muscle from non-muscle (i.e., adipose tissue) using voxel intensity within each border region for quantitative determination of muscle volume.

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Ages Eligible for Study: | 60 Years to 80 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Total Knee Arthroplasty surgical candidate
Exclusion Criteria:
- Overt muscle disease

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00760383
United States, Oregon | |
University of Oregon | |
Eugene, Oregon, United States, 97401-1240 | |
Slocum Center for Orthopedics and Sports Medicine | |
Eugene, Oregon, United States, 97401 |
Principal Investigator: | Hans C Dreyer, PT, PhD | Assistant Professor, Department of Human Physiology |
Publications of Results:
Other Publications:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: | Hans Dreyer, University of Oregon, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) |
ClinicalTrials.gov Identifier: | NCT00760383 |
Other Study ID Numbers: |
1K01HD057332 ( U.S. NIH Grant/Contract ) 1K01HD057332 ( U.S. NIH Grant/Contract ) |
First Posted: | September 26, 2008 Key Record Dates |
Results First Posted: | December 4, 2014 |
Last Update Posted: | December 4, 2014 |
Last Verified: | December 2014 |
Total Knee Arthroplasty Osteoarthritis Muscle Metabolism Rehabilitation Physical Therapy |
Osteoarthritis Arthritis Joint Diseases Musculoskeletal Diseases Rheumatic Diseases |