Relationship between knee osteoarthritis and the locomotive syndrome risk tests: A cross-sectional study

To determine the relationship between locomotive syndrome (LS) risk tests and knee osteoarthritis (KOA).

Cross-sectional cohort study.

In 2015, 225 people (male 84, females 141, mean age 67.9, range 30-90) were examined using LS risk tests, including the stand-up test, the two-step test, and the 25-question risk assessment, in Katashina Village in Gunma prefecture. The Japanese orthopaedic association defined LS risk test stage 1, difficulty with standing from a 40-cm-high seat using one-leg in the stand-up test, two-step test <1.3, the 25-question risk assessment ≧7, and defined stage 2, difficulty with standing from a 20-cm-high seat using both legs in the stand-up test, two-step test <1.1, the 25-question risk assessment ≧16. Persons with two or more of the following on the ultrasound (US) assessment were defined as having KOA: peripheral joint space (PJS) < 5 mm during weight-bearing; medial radial displacement (MRD) > 5 mm during weight-bearing; and osteophytes > 2 mm. If the residents had KOA in either knee, they were defined as having KOA.

45 residents had KOA in either knee. Logistic regression analysis adjusted for age, height, weight, gender, and knee pain was performed with stage 0 as reference. On the stand-up test, the odds ratio was 5.484 (95% confidence interval (CI) 1.966-15.297) for stage 1 and 2.067 (95% CI 0.426-10.017) for stage 2. On the two-step test, the odds ratio was 1.497 (95% CI 0.557-4.021) for stage 1 and 0.71 (95% CI 0.210-2.395) for stage 2. On the 25-question risk assessment, the odds ratio was 1.73 (95% CI 0.646-4.631) for stage 1 and 1.5 (95% CI 0.508-4.433) for stage 2.

A stand-up test of stage 1 had a significant relationship with KOA. This might suggest that proper care of KOA is needed to prevent progressive disability.