Muscular wellness of knee osteoarthritis people is preserved before 75 years old

Abstract

Aging causes a decrease in mass and muscle strength, leading to sarcopenia. Osteoarthritis not only joint but also muscle and ligaments, causes joint instability and muscle weakness. The objective is to measure the muscular quality of knee osteoarthritis patients under 75 years. We identified adults aged between 50 and 75 years with symptomatic knee osteoarthritis defined by ACR criteria and Kellgren and Lawrence score between I-IV. Pain (EVA) and function (WOMAC function) were assessed. The evaluation of the muscular quality was assessed by Skeletal Muscle Index (SMI), handgrip and Short Physical Performance Battery (SBBP). Normal values of muscle mass by SMI, mesured by Bio-impedance (BIA) are ≥ 10.76 kg/m 2 for men and ≥ 6.76 kg/m 2 for women, muscle strength by handgrip are ≥ 30 kg for men and ≥ 20 kg for women, and physical performance measurement by the SBBP score are 0–6; low performance, 7–9; intermediate performance and 10–12; high performance. One hundred and fifty patients were included (79.2% women), the mean age was 65.5 years (± 6.4), of which 37.9% were obese (BMI > 30). The mean score of Kellgren and Lawrence was 3 (± 0.83). Mean pain on VAS 5.0 (± 2.1) and WOMAC function mean score was 37.0 (± 19.0). The mean SMI was 12.57 (± 1.36) for men and 8.92 (± 1.41) for women. The mean handgrip score was 26.4 kg (± 10.5). The SPPB total score was 9.1 (± 1.1), with a low performance for 2.0%, intermediate performance for 74.7% and high performance for 23.3%. The muscular wellness of knee osteoarthritis patients is preserved, revealing no sarcopenia before 75 years. Muscle deconditioning and progression of sarcopenia induced by osteoarthritis symptoms might appear after 75 years old.