The study aimed to describe and analyse longitudinal use of intra-articular injections after treatment initiation among adults with radiographically confirmed knee osteoarthritis (OA) concluded that the proportion of patients switching injection use and one-time users was substantial.
The Osteoarthritis Initiative (OAI) data was used to enrol participants who were radiographically confirmed of suffering OA (Kellgren–Lawrence grade (K–L) ≥ 2) in ≥1 knee at baseline. A total data of 9 years was used in which, 412 participants newly initiating hyaluronic acid or corticosteroid injections with their index visit were identified. For each type of injection initiated the clinical and socio-demographic characteristics were described by patterns of treatments i.e. one-time use, switched, or continued injections. Multinomial logistic models evaluated the extent to which patient-reported symptoms (post-initial injection and changes over time) were associated with patterns of injection use.

The findings evaluated that of these initiating injections, ∼19% switched, ∼21% continued injection type, and ∼60% did not report any additional injections. In participants who initiated corticosteroid injections, greater symptoms post-initial injection were found to be associated with lower odds of continued use compared to one-time users (adjusted odds ratio (aOR) for Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain: 0.91; 95%, confidence interval (CI): 0.83 to 0.99; aORstiffness: 0.77; CI: 0.63 to 0.94; aORphysical function: 0.97; CI: 0.94 to 1.00). The symptom that changed with time (e.g., worsened or improved) were not correlated with patterns of injections use.
But the symptoms post-initial injection found to be linked with patterns of injection use. There is a need to explore patterns of the lack of impact on patient-reported symptoms.