Association Between Declining Walking Speed and Increasing Bone Marrow Lesion and Effusion Volume in Individuals with Accelerated Knee Osteoarthritis.

OBJECTIVE: To determine whether a decline in walking speed during the year prior to disease onset is associated with concurrent changes in cartilage, bone marrow lesions (BMLs), or effusion in adults who develop common knee osteoarthritis (OA), accelerated knee OA, or no knee OA.
METHODS: We identified 3 groups from the Osteoarthritis Initiative based on annual radiographs from baseline to 48 months: accelerated knee OA, common knee OA, and no knee OA. We used the cartilage damage index (CDI) to assess tibiofemoral cartilage damage and used a semiautomated program to measure BML and effusion volume. Walking speed was assessed as an individual's habitual walking speed over 20 meters. One-year change in walking speed and structural measures were calculated as index visit measurements minus measurements from the year prior visit. Logistic regression models were used to determine whether change in walking speed (exposure) was associated with change in each structural measure (outcome) for the overall group and then separately for the accelerated knee OA, common knee OA, and no knee OA groups.
RESULTS: Adults who slowed their walking speed were almost twice as likely to present with increased BML volume, with a significant association (odds ratio 3.04 [95% confidence interval (95% CI) 1.03-8.95]) among adults with accelerated knee OA. Adults with accelerated knee OA who slowed their walking speed were approximately 3.4 times (95% CI 1.10-10.49) more likely to present with increased effusion volume. Walking speed change was not significantly associated with CDI change.
CONCLUSION: A change in an easily assessable clinical examination (i.e., 20-meter walk test) was associated with concurrent worsening in BML and effusion volume in adults who developed accelerated knee OA.