Effects of amino acid supplementation on muscle mass, muscle performance and functional capacity in subjects undergoing total knee arthroplasty: a systematic review of randomized clinical trials.

The aim of the present study was to summarize the effectiveness of amino acid supplementation on muscle strength, muscle volume, and functional capacity in patients undergoing total knee arthroplasty. For this, in November 2022, a search was carried out in the PubMed, Cochrane Library, and EMBASE databases, identifying a total of 2182 documents, of which only 4 were included in the present review. The included studies had 148 participants (47 men and 101 women), with a minimum age of 53 and a maximum of 92 years, and supplementation times of 13 to 30 days (1 to 3 times a day). For the results, in relation to muscle performance, when comparing the control and experimental groups, greater muscle atrophy was observed in the pre- and post-moments of the control group, in relation to the experimental group. In addition, studies suggest a good tendency for muscle mass gain, and improvement in the functional capacities of patients who used supplementation. Therefore, the use of amino acids after TKA surgery reduces muscle atrophy, which preserves muscle mass and leads to better performance in tests of strength and functional capacity, when compared to the use of a placebo.

Analysis of mechanical variables in Hoffa fracture - A comparison of four methods by finite elements.

BACKGROUND: Correct management of Hoffa fractures is a challenge in the clinical context. Open reduction along with internal fixation should be the therapy of choice. Mechanical trials with the main internal fixation systems conducted by individualized finite element (FEM) models, to date, have been neglected. The aim of this study was to biomechanically analyze four fixation methods for the treatment of Type II Hoffa fracture (OTA Classification: 33B3.2∗ lateral) using FEM. METHODS: Four internal fixators were developed to treat Type II Hoffa fracture using finite elements: 4.5 mm cortical screws and 7 mm cannulated screw in anterior-to-posterior and posterior-to-anterior directions (4.5AP, 4.5 PA, 7AP and 7 PA). Under the same conditions, fractural deviation in the vertical, maximum and minimum principal and Von Mises directions in the syntheses used were evaluated. RESULTS: The vertical displacements evaluated were 0.7 mm, 0.5 mm, 0.8 mm and 0.3 mm; the values of maximum were 6.14 Mpa, 6.15 hPa, 6.0 Mpa and 6.2 Mpa, the values obtained from minimum data were 6.26 Mpa, -6.45 Mpa, -7.3 MPa and -6.8 Mpa and the maximum values of Von Mises peak stress were 185.0 Mpa, 194.1 Mpa, 143.6 Mpa and 741.4 Mpa, for the fixation models 4.5AP, 4.5 PA, 7AP and 7 PA, respectively. CONCLUSION: The 7 mm-cannulated screw fixation system yielded the best mechanical results evaluated by FEM in the treatment of Type II Hoffa fracture, causing a decrease in vertical displacement when used in retrograde and in Von Mises peak stress in anterograde.