Injectables for Osteoarthritis

Optimising Knee Osteoarthritis Treatment: What Is The Evidence Telling Us

Knee osteoarthritis (OA) is a leading cause of pain and disability, and sonographers, radiologists and clinicians play a crucial role in its management by administering intra-articular injections. Traditionally, corticosteroid (CS) injections have been the go-to option for pain relief, but recent research highlights both their limitations and the potential benefits of alternative treatments such as hyaluronic acid (HA) and platelet-rich plasma (PRP). This blog post summarises three key studies that provide insight into the long-term effectiveness and risks associated with these treatments.

Study 1: Very-High-Molecular-Weight Hyaluronic Acid vs. High-Molecular-Weight Hyaluronic Acid

A 15-year cohort study examined the efficacy of very-high-molecular-weight hyaluronic acid (VHMW-HA) compared to high-molecular-weight hyaluronic acid (HMW-HA) in knee OA management. Results showed that 73.44% of patients responded positively to HA injections, with VHMW-HA demonstrating superior long-term outcomes. The study found that patients receiving VHMW-HA required less frequent repeat injections (average 5.67 years vs. 1.95 years for HMW-HA), suggesting a more sustained therapeutic effect. This finding highlights VHMW-HA as a potential alternative for patients seeking long-lasting symptom relief, reducing the need for repeated interventions.

Aggarwal 2024

Study 2: The Risks of Corticosteroid Injections for Knee Osteoarthritis

Although intra-articular corticosteroid (IACS) injections remain a widely used pain management strategy, emerging evidence suggests significant risks. This study reviewed four key complications associated with IACS: accelerated OA progression, subchondral insufficiency fractures, osteonecrosis, and rapid joint destruction with bone loss. Some patients experienced an accelerated need for joint replacement following repeated CS injections. For sonographers and radiologists performing image-guided injections, these findings raise important questions about the long-term safety of corticosteroids, emphasising the need for careful patient selection and consideration of alternative therapies.

Kompel 2019

Study 3: Comparing Corticosteroids, Hyaluronic Acid, and Platelet-Rich Plasma

A systematic review and meta-analysis of 35 randomized controlled trials (RCTs) assessed the efficacy of CS, HA, and PRP injections in 3,348 patients with knee OA. Key findings include:

• CS and HA provided similar short-term symptom relief, with HA offering a slight advantage in long-term pain reduction, though not clinically significant.

• PRP demonstrated superior pain and functional improvement at mid- and long-term follow-ups, with results exceeding the minimal clinically important difference (MCID).

These findings suggest that while CS injections offer rapid but temporary relief, PRP may be the more effective option for patients seeking sustained improvement in knee OA symptoms.

Bensa 2024

Key Takeaways

1. VHMW-HA may be a preferred alternative to traditional HA injections, providing longer-lasting symptom relief and reducing the frequency of repeat procedures.

2. CS injections carry potential long-term risks, making it essential for imaging specialists to discuss these considerations with referring physicians and patients.

3. PRP demonstrates superior long-term benefits, positioning it as a promising option for patients requiring sustained pain relief and functional improvement.

Clinical Implications and Future Considerations

For sonographers and radiologists performing ultrasound-guided intra-articular injections, these findings highlight the need for a more evidence-based approach to knee OA treatment. While CS injections remain a widely requested intervention, their potential risks should prompt clinicians to consider alternative options such as HA (particularly VHMW-HA) and PRP. Engaging in discussions with referring physicians about these findings can help optimise patient outcomes and reduce reliance on short-term symptom management strategies.