May 23, 2021
Paper Review: Intra-articular Saline vs Corticosteroids vs PRP vs Hyaluronic Acid for Hip Osteoarthritis

Paper Review: Intra-articular Saline vs Corticosteroids vs PRP vs Hyaluronic Acid for Hip Osteoarthritis

Osteoarthritis (OA) is one of the most significant disease burdens worldwide. The hip is the second most common location of OA behind the knee. Most hip OA is primary, although it can be associated with other pediatric diseases of the hip or certain risk factors such as increasing age, obesity and high impact sports. The vast majority of patients will report insidious onset of worsening hip pain without any clear injury. Diagnosis is easily made on radiographs.

Case Vignette

You are treating a 51 year old female athlete with mild hip osteoarthritis. She is inquiring about non-surgical options as she wants to continue running. Which of the following would not be considered first line therapy?

A) Physical Therapy
B) NSAIDS
C) Intra-articular injection
D) Proper footwear

In this week’s blog post, we’re going to review the paper by Gazendam et al comparing intra-articular normal saline (NS) to corticosteroids (CS), platelet rich plasma (PRP) and hyaluronic acid (HA) for the treatment of hip OA.
There are many treatment options for hip OA. First line therapy is typically multimodal, including some combination of patient education, physical therapy and exercise, activity modification, weight loss (if appropriate) and pharmacotherapy including acetaminophen and NSAIDS. Often second line treatment includes injections into the joint, most commonly intra-articular (IA) injections. Although CS are the most common and least expensive, physicians may also consider injecting HA, PRP, and stem cells among others.
intra articular hip injection with ultrasound

Image 1. Example of intra-articular hip injection with ultrasound guidance (adopted from arthroscopytechniques.org)

IA injections seem to help. A 2015 meta-analysis found that intra-articular treatments were superior to NSAIDS for knee OA (Bannuru 2015). That group found HA to be most effective. Other studies have found varying degrees of benefits from various types of injections (We 2017, Migliore 2008, Bennel 2017, Dall’Oca 2019).

Corticosteroids involve injecting a strong anti-inflammatory medicine with the goal of reducing synovitis of the arthritic joint and thus decreasing symptoms. Hyaluronic acid injections are a synthetic form of synovial fluid designed to mimic native fluid and provide a high kilodalton, viscous solution acting as a cushion within the joint space. Platelet rich plasma uses a patient’s own concentrated platelets to promote healing of injured soft tissue structures and joints. Finally, the authors in this study used normal saline, commonly considered a placebo in studies, which may also have therapeutic benefits.

Study

The authors of this study performed a systematic review and meta-analysis of existing studies to compare these four treatment modalities (CS, HA, PRP, NS). Eligible studies must be randomised controlled trials assessing the efficacy of CS, HA, PRP and placebo (NS) for patients with hip OA. Ultimately, they included 11 RCTs comprising 1353 patients. Essentially, they concluded there was no difference between NS, CS, PRP and HA for hip OA at 2, 4 and 6 months. This was true for both low- and high molecular weight HA.
This study was a network meta-analysis that only included level 1 evidence which really helps the reader draw conclusions about comparative efficacy. They followed the Cochrane and PRISMA guidelines. Limitations include the (relatively) small sample size and that the authors did not compare IA injections to other modalities of nonoperative management. It also doesn’t appear to distinguish between the different stages of hip OA where management, including IA injections, can vary dramatically.

Summary

This is a strong study which provides level 5 evidence for management of hip OA. It doesn’t state that CS, PRP and HA don’t work, rather that there were no significant differences compared to NS at 2, 4 and 6 months. IA injections remain part of the multimodal management of non-surgical hip OA. There is probably some room for further investigation here as far as frequency of injections, combinations of injections and considering the effects of local anesthetics (which are also known to be chondrotoxic).

Case Conclusion

Answer C. Intra-articular injections are a major component of treating hip OA. This can include corticosteroids, platelet rich plasma and hyaluronic acid among other options. However this would not routinely be considered first line treatment. Physical therapy, NSAIDS and correcting footwear if necessary would be considered first line therapy.

Lespasio, Michelle J., et al. “Hip osteoarthritis: a primer.” The Permanente Journal 22 (2018).

Citations

  1. Gazendam, Aaron, et al. “Intra-articular saline injection is as effective as corticosteroids, platelet-rich plasma and hyaluronic acid for hip osteoarthritis pain: a systematic review and network meta-analysis of randomised controlled trials.” British Journal of Sports Medicine 55.5 (2021): 256-261.
  2. Bannuru, Raveendhara R., et al. “Comparative effectiveness of pharmacologic interventions for knee osteoarthritis: a systematic review and network meta-analysis.” Annals of internal medicine 162.1 (2015): 46-54.
  3. He, Wei-wei, et al. “Efficacy and safety of intraarticular hyaluronic acid and corticosteroid for knee osteoarthritis: A meta-analysis.” International Journal of Surgery 39 (2017): 95-103.
  4. Migliore, Alberto, and Mauro Granata. “Intra-articular use of hyaluronic acid in the treatment of osteoarthritis.” Clinical interventions in aging 3.2 (2008): 365.
  5. Bennell, Kim L., David J. Hunter, and Kade L. Paterson. “Platelet-rich plasma for the management of hip and knee osteoarthritis.” Current rheumatology reports 19.5 (2017): 1-10.
  6. Dall’Oca Carlo, Breda Stefano, et al. “Mesenchymal Stem Cells injection in hip osteoarthritis: preliminary results.” Acta Bio Medica: Atenei Parmensis 90.Suppl 1 (2019): 75.

2 Replies to “Paper Review: Intra-articular Saline vs Corticosteroids vs PRP vs Hyaluronic Acid for Hip Osteoarthritis”

  1. The problem with articles like this is that interventions are compared based only on subjective results of pain complaints. We should also look at the effects of these chemicals or interventions on a cellular level- chondrocytes, subchondral bone, capsule, ligaments as well as other periarticular tissues. Obviously they all have different physiologic effects that need to be measured differently as well.

    1. 100% agreed. There are multiple questions that remain unanswered. One is certainly what are the histological effects of these injections? Lots of opportunity for research but since its not a clinical driven outcome and requires pathology and microbiology, the number of physicians/researchers doing it is a lot smaller.

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