Individuals with accelerated knee osteoarthritis (OA) present with earlier worsening of knee structure and poorer patient-reported and physical function measures, including a decline in walking speed, compared with individuals who have a more common, gradual onset of knee OA, according to the results of a longitudinal analysis of data from the Osteoarthritis Initiative (OAI) published in Arthritis Care & Research.
The investigators sought to determine whether a decline in walking speed in the year prior to onset of disease is linked to concurrent changes in cartilage, bone marrow lesions (BMLs), or effusion in adults with common knee OA, accelerated knee OA, or no knee OA. They identified 3 groups of individuals within the OAI based on annual radiographs performed at baseline through 48 months: participants with accelerated knee OA (n=106; mean age, 64.5±8.4 years), participants with common knee OA (n=121; mean age, 59.4±8.4 years), and participants with no knee OA (n=119; mean age, 58.3±7.8 years).
Tibiofemoral cartilage damage was evaluated using the cartilage damage index (CDI) and BMLs and effusion volume were assessed using a semi-automated program. Walking speed was measured as a person’s habitual walking speed over 20 meters.
Adults who slowed their walking speed were nearly 2 times as likely to have increased BML volume, with a statistically significant association in adults with accelerated knee OA (odds ratio [OR], 3.04; 95% CI, 1.03-8.95). Moreover, individuals with accelerated knee OA who slowed their walking speed were approximately 3.4 times more likely to present with increased effusion (OR, 3.39; 95% CI, 1.10-10.49). Change in walking speed, however, was not significantly associated with changes in the CDI.
The investigators concluded that a significant relationship exists between a decline in a clinically accessible measure of physical function such as walking speed and specific changes in knee structure that are observed in individuals with accelerated knee OA. Similar associations in individuals with incident common knee OA or no knee OA were not observed. Additional studies are warranted to determine whether interventions that target declining walking speed will also generate improvements in knee structure outcomes.
Harkey MS, Price LL, McAlindon TE, et al. Declining walking speed associates with increasing bone marrow lesion volume and effusion volume in individuals with accelerated knee osteoarthritis [published online June 8, 2018]. Arthritis Care Res (Hoboken). doi:10.1002/acr.23613