Amino Acids Aid Recovery After Surgery

Good news has been announced for the many thousands of people who undergo arthroplasty every year. This surgical procedure, also known as total knee replacement, is effective in relieving pain and restoring mobility, but patients often suffer after surgery from weakness due to atrophied muscles, particularly in the quadriceps. A recent medical study carried out in the USA1 found that by administering essential amino acid supplements for some time before and after the surgery, debilitating muscle wastage of the quadriceps can be avoided. This problem has long been a drawback of knee replacement surgery, causing the mobility of recovering patients to be impaired, but essential amino acid supplementation is an effective and inexpensive way to avoid muscle wastage following the operation.

Background to the Study

A team of scientists at the University of Oregon gave amino acids to two groups of patients both before and after they had knee-replacement surgery. The patients’ average mean age was 69. One group, the control, was given a placebo consisting of a non-essential amino acid, while another group was given a mix of essential amino acids. These cannot be produced by the body and need to be ingested either as a supplement or via the diet. The eight essential amino acids used in the study were isoleucine, leucine, valine, lysine, phenylalanine, methionine, threonine and histidine. Administration of the supplements to the two groups was started one week before the surgery and continued until two weeks after surgery. The dosage, given twice a day, was 20 grams of essential amino acids and 40 grams of the placebo.

Findings of the Study

Before the operation and six weeks after surgery, all patients in the study were tested for various functional skills to assess their physical performance. Actions such as rising from a chair, climbing stairs and walking short distances took patients in the control group 32% longer after surgery than before. The group who had been taking essential amino acid supplements showed no reduction in movement. Pre- and post-surgery measurements were taken of the muscle mass of the quadriceps, an area that usually shows atrophy following arthroplasty. The placebo group showed a reduction of 18.4% muscle mass, while the group given EAA supplements had an average loss of only 6.2%.

Implications of the Study

While this study was relatively small, involving 28 patients, it showed clear evidence that a supplement of essential amino acids has a beneficial effect on post-operative patients by speeding up their recovery and improving their quality of life after TKA. Professor Hans C Dreyer, who led the team, sees supplementation as a cost-effective way to accelerate functional recovery and mitigate muscle atrophy and weakness. The findings of the clinical trial were published in the Journal of Clinical Investigation in 2013 and can be found online.

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