Hip osteoarthritis (OA) is a widespread global health issue, recognised as one of the leading causes of disability worldwide. This degenerative joint disease causes pain, stiffness, and reduced mobility, significantly impairing the quality of life for those affected. Hip OA does not only impact individuals physically but also emotionally, as it often leads to limitations in daily activities and independence. In severe cases, it can result in complete immobility, adding to the disease’s burden on both patients and healthcare systems.
In 2019, over 100,000 primary total hip replacements were performed in the United Kingdom, with costs exceeding £500 million. Alarmingly, nearly 90% of these surgeries were performed to address hip OA. These figures underline the profound economic and healthcare challenges posed by the disease. Despite the availability of surgical interventions, many patients endure years of suboptimal management in primary care before being referred for surgery. This delay often exacerbates their condition, highlighting a critical need for improvements in early diagnosis and treatment pathways.
Current Guidelines and Recommendations
Managing hip OA effectively requires a multifaceted approach, as highlighted by the National Institute for Health and Care Excellence (NICE). Their guidelines recommend combining several non-surgical strategies to help alleviate symptoms and improve patients’ quality of life. These include patient education, regular physical exercise personalised to the individual’s abilities, and weight management to reduce joint stress. Analgesics, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen, are also suggested to provide pain relief.
However, while these interventions can help manage symptoms, their effectiveness varies among patients. In cases where non-surgical strategies fail to provide sufficient relief, corticosteroid injections are often considered. While intra-articular corticosteroid injections are a widely accepted treatment for knee osteoarthritis, their use in hip OA remains a topic of debate. This is due to limited and conflicting evidence regarding their efficacy and safety for hip-specific applications. Understanding the role of these injections in hip OA management is critical for optimising treatment outcomes.
Evidence on Corticosteroid Injections
Research into the use of corticosteroid injections for hip OA is limited, with only a few clinical trials addressing this treatment approach. To date, five randomised controlled trials (RCTs) have investigated the effects of intra-articular corticosteroid injections on hip OA. These studies have included sample sizes ranging from 36 to 101 participants, which, while small, provide valuable insights into the potential benefits of this treatment.
Some RCTs have reported that corticosteroid injections combined with local anaesthetics can offer short-term relief from hip OA symptoms. Pain reduction and functional improvement were observed for up to eight weeks following the injections. However, the evidence is not uniform, and the small sample sizes in these studies limit the generalisability of the findings. The lack of a standardised methodology across trials further complicates efforts to draw definitive conclusions.
One of the most significant studies in this area is the largest RCT to date, which compared standard care with ultrasound-guided corticosteroid-lidocaine injections. This trial demonstrated significant improvements in pain and function during early follow-up periods, specifically from two weeks to four months after treatment. These findings suggest that corticosteroid injections can provide valuable relief during the initial stages of treatment, potentially improving patients’ quality of life during this period. However, by six months, differences in outcomes between the treatment and control groups were no longer statistically significant. This highlights the limitations of corticosteroid injections as a standalone treatment and the need for complementary or follow-up therapies to sustain long-term benefits.
Strengths and Limitations
The largest RCT investigating corticosteroid injections for hip OA had several strengths that make its findings relevant for clinical practice. The study’s large sample size allowed for more robust data analysis, while pragmatic recruitment strategies ensured that participants reflected real-world patient populations. High follow-up rates further enhanced the reliability of the findings. Additionally, the inclusion of two comparison groups provided a comprehensive view of treatment outcomes, enabling researchers to evaluate the relative benefits of corticosteroid-lidocaine injections against standard care.
Despite these strengths, the study faced several limitations. One of the primary challenges was its reliance on self-reported outcomes. While self-reported data can provide valuable insights into patients’ experiences, it is subject to bias and may not always accurately reflect clinical improvements. Recruitment challenges also impacted the study, resulting in a slightly underpowered sample size that may have limited the ability to detect smaller but clinically relevant differences between treatment groups.
Another notable limitation was the lack of diversity among study participants. The trial included only white participants, raising questions about the generalisability of its findings to other ethnic groups. Additionally, the study did not include a placebo arm, which would have provided a more rigorous comparison and helped isolate the effects of the corticosteroid injections. The absence of radiographic outcomes also meant that researchers could not assess the potential impact of the treatment on joint structure. Finally, high dropout rates in the control group posed challenges to data interpretation and may have introduced additional biases.
Clinical Implications of Corticosteroid Injections
The findings of the largest RCT highlight the potential benefits of corticosteroid-lidocaine injections when used as part of a broader treatment strategy for hip OA. By providing rapid pain relief and functional improvement, these injections can significantly improve patients’ quality of life during the initial months of treatment. This is particularly valuable for individuals experiencing severe symptoms that limit their ability to perform daily activities.
The mechanisms underlying the benefits of corticosteroid injections are multifaceted. Corticosteroids have well-documented anti-inflammatory properties, which can help reduce joint inflammation and alleviate pain. Lidocaine, a local anaesthetic, provides additional pain relief, allowing patients to regain mobility and function. The injections may also enhance patient engagement with their overall treatment plan, as the relief they provide can encourage individuals to participate more actively in physical therapy and other interventions.
However, it is essential to recognise the limitations of corticosteroid injections. While they can provide significant short-term relief, their benefits tend to diminish over time, with no significant differences observed between treatment and control groups by the six-month mark. This underlines the importance of incorporating additional therapies to sustain long-term improvements in symptoms and function.
Addressing Safety and Long-Term Effects
The safety of corticosteroid injections for hip OA remains a critical area of concern. Adverse reactions have been reported, including a single case of subacute bacterial endocarditis that may have been related to the treatment. Additionally, there are concerns about the potential impact of repeated injections on joint health. Some studies have suggested that repeated corticosteroid injections may contribute to cartilage volume loss and accelerate the progression of radiographic OA. These findings highlight the need for further research to assess the long-term safety of this treatment approach.
Imaging studies could play a vital role in addressing these concerns. For example, advanced imaging techniques could help identify early signs of cartilage damage or other structural changes in the joint, enabling clinicians to monitor the effects of corticosteroid injections more closely. Future research should also investigate strategies for minimising potential risks, such as optimising the timing and frequency of injections.
Research Priorities
To refine the role of corticosteroid injections in hip OA management, future research should focus on several key areas. One priority is the development of stratified treatment approaches that use imaging indicators, such as synovitis, to predict which patients are most likely to benefit from corticosteroid injections. This could help ensure that treatments are personalised to individual patient needs, maximising their effectiveness.
Another important area of investigation is the exploration of alternative administration routes for corticosteroids. For example, intramuscular injections may offer a safer and more effective option for delivering corticosteroids to patients with hip OA. Research should also evaluate the safety, effectiveness, and optimal timing of repeated injections, as well as the potential for combining corticosteroid injections with other therapies to enhance outcomes.
Understanding the contextual effects of treatments is another critical area for exploration. Factors such as patient expectations, clinician-patient interactions, and the psychological impact of receiving targeted treatments may all influence outcomes. By studying these effects, researchers can gain a more comprehensive understanding of how to optimise treatment strategies for hip OA.
Finally, future studies should prioritise diversity and inclusivity in their design. Expanding research to include participants from a broader range of ethnic and demographic backgrounds will enhance the generalisability of findings and ensure that treatment recommendations are equitable and applicable to all patient populations.
Conclusion
Corticosteroid-lidocaine injections represent a promising option for managing hip osteoarthritis, particularly for patients experiencing severe symptoms. These injections provide rapid and meaningful improvements in pain and function, offering much-needed relief during the initial months of treatment. However, their benefits are primarily short-term, with diminishing effects observed after six months.
While these findings support the inclusion of corticosteroid injections as part of a broader treatment strategy for hip OA, they also highlight the need for additional or complementary therapies to sustain long-term improvements. Addressing safety concerns and refining the use of corticosteroid injections through stratified treatment approaches and advanced imaging techniques will be essential for optimising their role in hip OA management.
By prioritising research into these areas, clinicians can better support patients in managing the challenges of hip OA, ultimately improving their quality of life and reducing the burden of this debilitating condition. With continued advancements in our understanding of hip OA and its treatment, there is hope for more effective and equitable care for all individuals affected by this disease.
References
Paskins, Z., Bromley, K., Lewis, M., Hughes, G., Hughes, E., Hennings, S., Cherrington, A., Hall, A., Holden, M. A., Stevenson, K., Menon, A., Roberts, P., Peat, G., Jinks, C., Kigozi, J., Oppong, R., Foster, N. E., Mallen, C. D., & Roddy, E. (2022). Clinical effectiveness of one ultrasound guided intra-articular corticosteroid and local anaesthetic injection in addition to advice and education for hip osteoarthritis (HIT trial): single blind, parallel group, three arm, randomised controlled trial. BMJ (Clinical Research Ed.), 377, e068446. https://doi.org/10.1136/bmj-2021-068446
McCabe, P. S., Maricar, N., Parkes, M. J., Felson, D. T., & O’Neill, T. W. (2016). The efficacy of intra-articular steroids in hip osteoarthritis: a systematic review. Osteoarthritis and Cartilage, 24(9), 1509–1517. https://doi.org/10.1016/j.joca.2016.04.018