Knee pain in older people may be associated with greater back pain/disability, according to a study published in Arthritis Research & Therapy.
A total of 4638 participants (average age at baseline, 62.4 years), selected from an initial cohort of 9764 community residents age ≥50 years, were asked to complete 2 questionnaires regarding their knee pain and demographic data at baseline and again after an average of 5.4 years.
A total of 64.8% of participants were women. The average body mass index (BMI) in the cohort was 22.5 kg/m2, and average scores on the Japanese Knee Osteoarthritis Measure (32-point scale) were 1.1 at baseline and 2.8 at follow-up. If a participant’s score increased by 3 or more points (9%), they were considered to have a “new symptom.”
Of the total population, 1262 participants were deemed to have new knee pain after 5 years. Older age, female sex, higher BMI, weight increase, worse mental health, and the presence of low back pain/disability were identified as significant factors for the development of knee pain. A predictive score on a 0 to 14 scale was created, based on identified risk factors. Being age 70≤ years was associated with a score of 4 points, and having a BMI of ≤25 kg/m2 added 3 points to the score. Depending on a participant’s total score, the risk for developing new knee pain ranged from 11.0% to 63.2%.
Study limitations include the lack of confirmation of the origin of knee pain symptoms.
“The current study shows that a self-reported score without any invasive tests can be sufficient to select people at risk with a desirable probability. The actual potential of the developed score should be verified in the future,” noted the study authors.
Ito H, Tominari S, et al. Low back pain precedes the development of new knee pain in the elderly population; a novel predictive score from a longitudinal cohort study [published online April 15, 2019]. Arthritis Res Ther. doi:10.1186/s13075-019-1884-0