Knee vs hip single-joint intra-articular hyaluronic acid injection in patients with both hip and knee osteoarthritis: a pilot study.

Comparison of Single-Joint Hyaluronic Acid Injections in Multi-Joint Osteoarthritis

This clinical study aims to compare the efficacy of single-joint hyaluronic acid (HA) injections in the knee versus the hip for patients suffering from osteoarthritis (OA) in both joints. The research focuses on evaluating pain relief and functional recovery to determine the effectiveness of localized treatment when multiple joints are affected by OA.

Study Methodology and Patient Demographics

The study enrolled 38 patients diagnosed with concurrent hip and knee osteoarthritis. Participants were divided into two distinct groups to receive a series of three HA injections administered at one-week intervals. The clinical evaluation utilized the following standardized metrics to measure progress:

• Visual Analog Scale (VAS): Used to assess pain levels during both activity and rest.
• WOMAC Index (5-point Likert 3.0): Used to evaluate pain, stiffness, and physical function.
• Timeline: Measurements were recorded prior to the first injection and one month following the third injection.

Clinical Outcomes: Knee vs. Hip Injection Groups

The results revealed varying degrees of improvement between the two groups. While both groups benefited from the treatment, the hip injection group showed a broader range of significant clinical improvements across all measured parameters.

Knee Injection Group Results

In the knee injection group, the intragroup analysis demonstrated significant improvements in VAS activity pain, VAS rest pain, and WOMAC pain values. However, no significant statistical differences were detected in WOMAC stiffness, WOMAC physical function, or WOMAC total scores following the treatment.

Hip Injection Group Results

Patients in the hip injection group experienced comprehensive recovery. Significant improvements were recorded across all categories, including VAS activity and rest pain, as well as WOMAC pain, stiffness, physical function, and total values.

Comparative Analysis of Treatment Efficacy

Final Conclusion on HA Injections for OA

Although the comparison of differences between the two groups was statistically not significant (p > 0.05), the hip injection group demonstrated higher overall improvement values. The study implies that intra-articular single-joint HA injections—whether applied to the knee or the hip—are effective therapeutic options for managing pain and functional status in patients with multi-joint osteoarthritis involvement.