Hyaluronic Acid Injections in Patients with Hip Osteoarthritis: A Systematic Review

Research Article

Austin Arthritis. 2016; 1(2): 1007.

Hyaluronic Acid Injections in Patients with Hip Osteoarthritis: A Systematic Reviews

Slaunwhite E¹, Al-Qarni A² and Wong IH³*

¹Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada

²Division of Orthopaedic Surgery, Capital District Health Authority, Halifax, Nova Scotia, Canada

³Sports Medicine, Dalhousie University, Halifax, Nova Scotia, Canada

*Corresponding author: Wong IH, Sports Medicine, Dalhousie University Halifax, Nova Scotia, Canada

Received: April 20, 2016; Accepted: May 23, 2016; Published: May 26, 2016


Osteoarthritis (OA) is a major cause of pain and disability characterized by continual loss of cartilage, osteophyte formation, synovitis, and possible soft tissue damage. Intra-articular injections of corticosteroids or Hyaluronic Acid (HA) are used as an intervention when symptoms are refractory to other medical management options, or to delay a total hip replacement operation. HA is conceptually superior compared to other intra-articular injections as it is not suspected to expedite cartilage breakdown with serial injections and could potentially have a longer lasting therapeutic benefit than corticosteroids. Intraarticular injection of HA for symptom management of OA has the potential to increase viscosity of synovial fluid and provide pain relief to patients. Currently there is inconclusive evidence on the benefit of HA in patients with hip OA. Given the need for consensus, this systematic review evaluated the current literature to determine the benefit of HA injections in the hip. A review of databases including EMBASE, Pubmed, MEDLINE, and Cochrane Clinical Trial Register was conducted and two authors independently assessed all of the studies. Inclusion criteria dictated that only five randomized controlled trials involving the treatment of hip OA with HA compared to a control injection were considered. Five studies satisfied the inclusion criteria, and were subsequently used for analysis. Two out of four papers demonstrated significant improvement in outcome scores when HA was compared to placebo or local anesthetic injections. Two out of three papers showed no difference in outcome scores between HA and Corticosteroid injections. The third study that compared HA and Corticosteroids showed greater improvement for corticosteroid injected patients in early follow-up, but HA was shown to be superior in patients with high-grade disease in later follow-up. Given these results, it may be important to focus on patients with a higher grade of OA who may be more likely to benefit from HA injections in the hip in future research. Our recommendations for future research would be to continue evaluation of HA in the form of randomized controlled trials.

Keywords: Hyaluronic acid; Hip; Osteoarthritis


Osteoarthritis (OA) is a chronic disease accompanied by increasing pain and is characterized by the continual degradation of cartilage, formation of osteophytes, presence of synovitis, and possible soft tissue damage. OA affects multiple domains of a patient’s health, including physical function, social activities, relationships, socioeconomic status, emotional well being, and body image [1]. The prevalence of knee and hip joint OA is 9% in the general population [2].

Current Osteoarthritis Research Society International (OARSI) guidelines for hip OA were last published in 2008 and include nonpharmacologic recommendations for the management of OA such as education, exercise, weight loss if overweight, and walking aids [3]. If these methods failed there are limited pharmacologic interventions available for patients, which include acetaminophen/paracetamol and NSAIDS, and finally intra-articular injections hyaluronic acid or corticosteroids. If all these interventions fail to alleviate the symptoms of OA, joint replacement can be considered in appropriate patients [3]. The American College of Rheumatology (ACR) guidelines do not currently recommend intra-articular HA injections, duloxetine, or topical NSAIDs due to a lack of evidence [4].

Although current guidelines show conflicting recommendations, several intra-articular injections are currently successfully used in patients who are refractive to other methods of intervention in clinical practice [5,6]. However, intra-articular injections of hyaluronans, glucosamine/chondroitin, and corticosteroids remain controversial [7,8].

Intra-articular injection of Hyaluronic Acid (HA) is currently used as one option for conservative treatment of OA in the hip. HA is an organic polysaccharide produced by chondrocytes, synoviocytes, and fibroblasts. HA forms parts of connective, epithelial, and neural tissues and is necessary in maintaining the viscosity of the synovial fluid and protect the joint from inflammation and degradation [9]. Beyond the viscosity effects of HA in synovial fluid, HA also has a role in preventing fibronectin fragment mediated cartilage injury by coating the articular surface [10], providing chondroprotective effects on joint cells chondrocytes and synoviocytes [11], and reducing nociceptive activity [12]. The concentration of HA in joints decreases with age and a reduced concentration of HA has been seen in knees plagued with OA compared to normal knees [13]. Therefore, it is thought that intra-articular injection of HA into the joint affected by OA could increase the viscosity of synovial fluid, decrease inflammation, and decrease pain.

Intra -articular injections of HA have been used in clinical practice in spite of the fact that the therapeutic effect has not been extensively evaluated. Therefore, our goal was to perform a systematic review to evaluate the benefit of HA injections in the context of OA in the hip and to determine clinical situations in which this treatment would be most appropriate.


Search strategy

Our search identified randomized controlled trials that involved intra-articular treatment of OA in the hip using HA and a control. Our search included all HA products, types of administration, and grades of OA. We performed a comprehensive literature search that included all articles up until July 2014 using multiple databases including Pubmed, MEDLINE, Cochrane Clinical Trial Register, and EMBASE. The searches were independently performed and the results collected by two researchers. Using the following search terms: (Hyaluronic acid [MeSH] AND (hip osteoarthritis [MeSH] or hip arthritis) AND (randomized controlled trial [pt] OR controlled clinical trial [pt] OR randomized [tiab] OR placebo [tiab] OR drug therapy [sh] OR randomly [tiab] OR trial [tiab] OR groups [tiab] NOT (animals [mh], we found 192 papers.

Selection of studies

To select the appropriate studies, two researchers who met after each review to compare results conducted a review of the search results independently. First the title was reviewed, then the abstract, and finally the entire paper for inclusion or exclusion. Studies were included if they met the criteria of being a randomized controlled trial involving the treatment of hip OA with HA compared to a control injection group (for example saline, local anesthetic, or corticosteroid injections). The outcome of interest was pain and function at followup visits after receiving HA or control injection. We excluded studies involving joints other then the hip, systematic reviews, prospective and retrospective studies, observational studies with no control, and animal studies. All studies were independently assessed for inclusion based on our criteria and disagreement between reviewers was resolved by discussion.


The initial search from all databases produced 192 studies. Following the title, abstract, and full text review five RCTs were deemed to be relevant and eligible for our review (Figure 1).

Study characteristics

Table 1 demonstrates the characteristics and patient demographics of the five randomized control trials that were selected for our systematic review analysis. Two studies compared HA to a placebo (either saline or local anesthetic), one study compared HA to corticosteroid, and two studies compared HA to corticosteroid and saline. The primary outcome measure selected for comparison amongst the studies was WOMAC or lequesne index and the secondary outcome measure was pain or patient global assessment. Baseline characteristics of patients including age, ratio of male to female, and disease severity were similar amongst all studies.