Gait analysis for knee osteoarthritis: Significant increase in stride length and walking speed with one OSTENIL® PLUS injection

In osteoarthritic joints, there is an increased concentration of free radicals. Hyaluronic acid is sensitive to oxidative stress and can be depolymerised by free radicals. Polyols are effective antioxidants that can be used to counteract depolymerisation. Simultaneously, polyols stabilise hyaluronic acid and reduce joint inflammation.^1,2 The new generation of hyaluronic acid products is therefore stabilised with polyols such as mannitol or sorbitol to protect against depolymerisation.

The aim of a recent study by Pereira et al.³ was to compare the efficacy of two hyaluronic acid products cross-linked with different polyols in patients with radiologically confirmed knee osteoarthritis. The prospective, randomised and controlled pilot study included 22 patients with Ahlbäck grade II–III knee osteoarthritis (obliteration of the joint space, minor bone attrition). Nine of these patients were given an injection of OSTENIL® PLUS (2% hyaluronic acid plus mannitol), five patients an injection of Synolis VA (2% hyaluronic acid plus sorbitol) and eight patients an injection of sterile saline (placebo group).

To test the efficacy, a sensor-based gait analysis over a distance of 60 meters with the following parameters was used:

• Walking speed
• Stride length
• Cadence (steps/minute)
• Swing duration

Additional clinical scores observed were:

• Knee Society score
• VAS pain and VAS stiffness
• WOMAC score

Follow-up observations in this study lasted four weeks. It was clear that the patients in the OSTENIL® PLUS group benefited most from the treatment. The authors reported that walking speed and stride length were the most significant parameters with respect to the efficacy of the intra-articular injections.​

After four weeks, there was a significant increase in walking speed in the OSTENIL® PLUS group of 0.076 m/s (p=0.039). This was 13% higher than the mean difference between healthy individuals and those with knee osteoarthritis.	In the OSTENIL® PLUS group, there was also a clear improvement in stride length after four weeks. The significant increase in stride length in the OSTENIL® PLUS group was 0.055 m (p = 0.027).	There was also a statistically significant improvement in the Knee Society score in the OSTENIL® PLUS group. After four weeks, it improved by 15 points (p=0.047).

 

In the other two comparison groups, the Synolis VA and the placebo group, no statistically significant changes in the gait and clinical parameters were found after four weeks.

► SUMMARY
In patients with knee osteoarthritis, just one injection of OSTENIL® PLUS led to a statistically significant improvement of stride length and walking speed. There was also a significant improvement in the Knee Society score (pain, symptoms, activities of daily living, exercise and free time and knee-related quality of life).

1 Belda JI et al., Hyaluronic acid combined with mannitol to improve protection against free-radical endothelial damage: experimental model. J Cataract Refract Surg. 2005; 31: 1213–8. 
2 Mongkhon JM et al., Sorbitol-modified hyaluronic acid reduces oxidative stress, apoptosis and mediators of inflammation and catabolism in human osteoarthritic chondrocytes. Inflamm Res. 2014; 63: 691–701.
3 Pereira et al., Gait analysis following single-shot hyaluronic acid supplementation: a pilot randomized double-blinded controlled trial, Pilot and Feasibility Studies 2019; 5: 56.