In a randomized, placebo-controlled trial published in BMC Musculoskeletal Disorders, diclofenac etalhyaluronate (DF-HA) showed a statistically significant change from baseline in numerical rating scale (NRS) for pain over 12 weeks following the first injection among persons with symptomatic osteoarthritis (OA). The purpose of this study was to evaluate if DF-HA was effective for non-knee OA, and how its efficacy differed between the affected joints.

Individuals (age 20 years or above) diagnosed with OA of ankle, hip, shoulder, elbow were randomly allocated 1:1 into DF-HA 30 mg and placebo (buffer solution-citric acid-sodium citrate) groups. Overall, 370 individuals were assessed, and 290 were registered and randomly allocated to receive three injections of either DF-HA (hip= 46, shoulder=45, ankle=30 and elbow=25) or placebo (hip=44, shoulder=45, ankle=30 and elbow =25)  in the target joint cavity every four weeks.

The volunteers were followed up for 12 weeks after the initial injection. The key outcome was average change in an 11-point NRS for pain during 12 weeks, evaluated for each joint. Treatment-emergent adverse events were documented, and radiographic changes in each joint were assessed. In the DF-HA group, there was no improvement in any endpoints compared to the placebo group in OA of the ankle, shoulder, and elbow. In the case of hip OA, however, statistically significant improvement was seen. At all the time points from weeks 1-12, the alteration from baseline in hip joint was higher with DF-HA compared to placebo.

No significant adverse events or radiographic alterations were noted.  DF-HA generated better effects in weight-bearing joints when compared to the non-weight-bearing joints. The differences in results between joints may be explained in part by differences in daily load on each joint, which may have influenced pain assessment.  In individuals with hip OA, intra-articular DF-HA generated a speedy response with a good safety profile and analgesia lasting 12 weeks when delivered every 4 weeks.