Clinical features and myofascial pain syndrome in older adults with knee osteoarthritis by sex and age distribution: A cross-sectional study.

Background: A source of myofascial pain and myofascial trigger points (MTrPs) in muscles of the knee area could play a crucial role in the management of pain in osteoarthritis patients. The aim of this study was to describe and compare demographic, clinical and myofascial pain syndrome characteristics in older adults with knee osteoarthritis by sex and age distribution.

Methods: A cross-sectional study was carried out. 114 patients with osteoarthritis were recruited in older-adult care centers. The diagnosis of active and/or latent MTrPs (AMTrPs/LMTrPs) was performed. Numerical Pain Rating Scale, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Barthel Index, Timed Up and Go Test (TUG), Mini-Mental State Examination, EuroQol Group 5-Dimension Self-Report Questionnaire, chronicity, number of falls, and medication use were collected. All data were compared by sex (male or female) and age (< 70, 70-80, or > 80 years) distributions.

Results: The most prevalent muscles with AMTrPs and LMTrPs were the quadriceps vastus medialis (75.43%) and lateralis (65.78%), respectively. The clinical characteristics showed significant differences (P<0.05) for chronicity, WOMAC functionality and total scores, TUG, falls rate and medication between males and females, as well as for chronicity, Barthel index and TUG between age distributions. There were not any significant differences (P>0.05) by sex or age distribution according to the number and presence of active and latent MTrPs.

Conclusions: The demographic and clinical features of older adults with knee osteoarthritis may be influenced by sex and age distribution. Nevertheless, the myofascial pain syndrome associated with knee osteoarthritis did not seem to be related to sex or age distribution.