Wondering how to lubricate stiff joints? Modern joint injections claim to replicate the lubricating and cushioning functions of natural synovial fluid—but how well do they really work, especially in foot and ankle joints? LFAC’s Matthew Solan explains.
Joint pain, in the ankle as well as the knees and hips, is one of the most common complaints as people age. For many, it leads to significant discomfort, reduced mobility, and a diminished quality of life.
One treatment approach that has gained traction over the years involves injecting lubricants or shock-absorbing substances directly into the joints to alleviate pain and improve function. These injections, often referred to as viscosupplementation, typically involve the use of hyaluronic acid (HA) or other synthetic lubricants.
But, do these products actually bring benefit for patients?
While the idea of lubricating or cushioning damaged joints seems intuitive—much like oiling a squeaky hinge – questions have arisen regarding the effectiveness of these treatments. Are they truly beneficial, or are they largely driven by the interests of the pharmaceutical and medical device industries? And do they work better than a placebo, or is the relief patients feel largely psychological? This article will delve into the science behind these treatments, scrutinize the evidence supporting them, and examine the role of industry in their promotion.
The Theory: How Do Joint Injections Lubricate Stiff Joints?
Hyaluronic acid (HA) injections are among the most well-known treatments that fall under the umbrella of viscosupplementation. HA is a naturally occurring substance in the body that plays a key role in joint function by helping maintain the viscosity and elasticity of the synovial fluid, which lubricates joints and acts as a shock absorber during movement.
In people with osteoarthritis (OA), particularly in the knee, the synovial fluid becomes less viscous, reducing its ability to lubricate and cushion the joint. This can lead to increased friction between the bones, causing pain, inflammation, and further joint degradation.
The rationale behind HA injections is to restore this lost lubrication and provide cushioning, thereby improving joint function and reducing pain. For those desperate to know how to lubricate stiff joints, it’s something to believe in.
What substances are used in joint injections?
The main substances used in joint injections for lubrication and shock absorption include:
- Hyaluronic Acid (HA): Often derived from rooster combs or produced synthetically, HA injections are designed to increase the viscoelasticity of the synovial fluid. The treatment is particularly popular for knee osteoarthritis but has also been used in other joints like the hip, shoulder, and ankle.
- Steroid Injections: Though not considered a lubricant or shock absorber, corticosteroid injections are often used in tandem with HA or as an alternative, aiming to reduce inflammation rather than restore lubrication.
- Synthetic Lubricants and Hydrogels: Some newer treatments involve synthetic substances designed to mimic the shock-absorbing properties of natural cartilage. These are still under research and not as widely used as HA.
Is Hyaluronic Acid Effective Or A Placebo?
Numerous studies have sought to determine whether hyaluronic acid injections genuinely provide relief for joint pain or if their perceived benefits are no better than a placebo effect. The results are mixed, with some studies showing modest benefits while others show little to no improvement over placebo injections.
- Efficacy in Knee Osteoarthritis: Several meta-analyses (huge studies that bring all avaialble data together for analysis) have examined the efficacy of HA injections for knee osteoarthritis, with varying conclusions. For instance, a 2015 review published in the Journal of the American Medical Association) JAMA analyzed the results of multiple randomized controlled trials (RCTs) and found that, while some patients reported reduced pain and improved function, the overall benefit was small and not clinically significant. The authors concluded that the efficacy of HA was questionable, especially when compared to placebo. On the other hand, some studies suggest that certain patients, particularly those in the earlier stages of osteoarthritis, might experience more significant relief. A study published in The American Journal of Sports Medicine indicated that patients with mild to moderate osteoarthritis reported improvement in symptoms following HA injections, but those with severe osteoarthritis did not see similar benefits . This variability may explain the conflicting results in the literature.
- Effectiveness Beyond the Knee: The evidence for HA injections in joints other than the knee, such as the hip, shoulder, and ankle, is even less convincing. Fewer studies have been conducted in these areas, and the results tend to be inconsistent. The difficulty with these joints is that they are deeper and harder to access, which may contribute to reduced efficacy compared to knee treatments.
Placebo Effect: The placebo effect plays a large role in pain treatments, and injections are no exception. Placebo-controlled trials (half of the volunteers have a new injection treatment, the others still have an injection, but with “pretend treatment “ like saline) often reveal that patients experience significant pain relief even when they receive an injection of saline (a placebo) rather than an active substance. This could be due to the psychological effects of receiving a treatment, the act of injecting a joint (which may temporarily reduce inflammation due to the mechanical action), or the body’s natural healing processes being stimulated.
One analysis found that HA injections had a slightly better outcome than placebos but questioned whether the difference was clinically relevant. Many patients in the placebo groups also experienced pain relief, leading researchers to argue that the placebo effect plays a significant role in the perceived efficacy of viscosupplementation .
Industry Influence: Is the Treatment Driven by Profit?
As with many treatments in modern healthcare, the question arises whether the promotion of joint injections, particularly with hyaluronic acid, is more driven by industry interests than by robust scientific evidence. Less led by a desire to help those desperate to know how to lubricate stiff joints, and more a way to earn more money.
The global market for viscosupplements is substantial, and manufacturers of hyaluronic acid injections, medical device companies, and private healthcare providers have a financial stake in promoting these treatments. Some industry critics argue that the popularity of HA injections is driven in large part by aggressive marketing campaigns and the promise of a relatively simple, minimally invasive solution for joint pain, rather than by solid clinical evidence.
The FDA (Food and Drug Administration) in the USA approved hyaluronic acid injections for knee osteoarthritis in 1997, and since then, the market has grown steadily. Pharmaceutical companies have invested heavily in promoting these injections to physicians and patients alike. The promise of “restoring lubrication” to a worn-out joint is appealing, especially when the alternative might be more invasive, such as surgery or a joint replacement. However, many experts caution that the evidence for long-term benefits does not fully support the enthusiastic promotion of these injections.
Conflict of Interest in Research
There is also evidence to suggest that some studies demonstrating the effectiveness of hyaluronic acid injections may be influenced by conflicts of interest. Researchers with financial ties to pharmaceutical companies that manufacture HA products may be more likely to publish positive findings, leading to biased conclusions. A 2016 review found that industry-funded studies were more likely to report favorable results for HA injections compared to independent studies . This raises concerns about the objectivity of the research promoting viscosupplementation.
Alternative Treatments: Are Lubricating Injections Better Than Surgery For Stiff Joints?
For joint pain, especially due to osteoarthritis, there are several treatment options available besides viscosupplementation. Some of the most common alternatives include:
- Physiotherapy: Many patients with osteoarthritis or joint pain benefit from physical therapy, which helps strengthen the muscles around the joint, improve range of motion, and reduce pain. Physiotherapy has robust evidence supporting its efficacy, especially when combined with lifestyle changes such as weight-loss management and activity modification.
- Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Oral NSAIDs, like ibuprofen or naproxen, are commonly used to manage osteoarthritis pain. While these drugs do not alter the underlying disease, they effectively reduce inflammation and pain. However, long-term use carries risks such as gastrointestinal problems (indigestion or ulcers) and cardiovascular issues (blood pressure and heart attacks).
- Corticosteroid Injections: Corticosteroid injections are a common alternative to HA injections. While they reduce inflammation effectively, their effects tend to be short-lived, and frequent use can lead to joint damage over time.
- Joint Replacement Surgery: For patients with advanced osteoarthritis, joint replacement surgery may be the only option to significantly improve mobility and quality of life. However, surgery is invasive and carries significant risks, including infection, blood clots, and the potential need for future revisions.
When Are Injections Worth Considering?
Despite the debate over the effectiveness of joint injections for lubrication and shock absorption, there are certain circumstances where they may be worth considering:
- For Patients Who Cannot Undergo Surgery: For older adults or individuals with significant comorbidities who are not good candidates for surgery, HA injections may offer temporary relief and improve quality of life, even if the benefits are modest.
- For Patients With Early-Stage Osteoarthritis: Some evidence suggests that HA injections may be more effective for patients with mild to moderate osteoarthritis, delaying the need for more invasive interventions like joint replacement.
- As Part of a Comprehensive Treatment Plan: Joint injections should not be seen as a standalone treatment but rather as part of a broader, multimodal approach to managing joint pain. Combining injections with physical therapy, weight management, and medications may provide better outcomes than relying on injections alone.
Conclusion: Evidence vs. Industry Influence
The evidence for joint injections using lubricants and shock absorbers, particularly hyaluronic acid, is mixed at best. While some patients may experience modest improvements in pain and function, the benefits often appear small and may not be clinically significant compared to a placebo. Additionally, the role of industry in promoting these treatments raises questions about the objectivity of the research supporting their use.
While HA injections may be worth considering for certain patients—particularly those in the earlier stages of osteoarthritis or those who cannot undergo surgery—they are unlikely to provide dramatic or long-lasting relief for most individuals. Given the placebo effect and the availability of other evidence-based treatments, it is important for patients and clinicians to weigh the potential benefits and limitations of viscosupplementation carefully. In many cases, conservative treatments, such as physical therapy, weight management, and NSAIDs, may offer more reliable and cost-effective alternatives.
Struggling with stiff joints or considering injections? Contact our team to discuss whether joint lubrication treatments are right for you.
Q – How can I lubricate stiff joints without surgery?
Joint injections with hyaluronic acid aim to mimic the natural lubrication of synovial joints. Evidence in ankles is weak, though they are safe and commonly used.
Q – Are lubricant injections effective for ankle joints?
Current research shows limited benefit in ankle joints. Most studies focus on knees, with mixed results in foot and ankle applications.
Mr Matthew Solan
Mr Matthew Solan is a consultant orthopaedic surgeon, dealing in all foot and ankle disorders. He has been with LFAC since its formation in 2003.
