EUROVISCO Recommendations for the Use of Viscosupplementation with Hyaluronic Acid in the Management of Hip Osteoarthritis

Abstract

Background

Viscosupplementation (VS) by intra-articular injections of hyaluronic acid (HA) is an increasingly used treatment of hip osteoarthritis (OA). However, there are no clear European recommendations for its use.

Methods

Twelve members of the European Viscosupplementation Consensus Group (EUROVISCO), made up of rheumatologists, orthopedic surgeons, and rehabilitation physicians from European countries, were asked to make a therapeutic decision on 23 statements based on an exhaustive analysis of the literature and their clinical experience, using the Delphi method. For each statement, the strength of agreement and the level of consensus were calculated by the chairman of the group

Results

The expert panel reached unanimous or high consensus, either for or against, on 16 of the proposed statements. The main ones are: Current evidence and the results of observational trials support the use of VS in patients with hip OA who do not require surgery. VS is more effective in cases of mild to moderate hip OA. Hip VS is safe and well tolerated, even with repeated injections. The outcome of VS depends on the viscosupplement used. A standard X-ray must be obtained before deciding on VS. VS must be performed under imaging guidance. A single injection regimen is preferable to repeat injections. VS can be considered for individuals who wish to postpone surgery. Hip replacement surgery should not be performed within 3 months of VS. VS should not be used to treat an osteoarthritis flare. VS is part of a multimodal treatment for hip OA.

Conclusion

This set of recommendations is intended to help practitioners make decisions about HA VS in patients with OA.

Keywords

hyaluronic acid viscosupplementation recommendations hip osteoarthritis guidelines EUROVISCO

Introduction

Hip osteoarthritis (OA) is a prevalent condition worldwide significantly impacting individuals quality of life and imposing a substantial economic burden on healthcare systems. Global prevalence of hip OA is reported to be at 8.55%, with higher rates observed in Europe (12.59%) compared with Africa (1.20%), Asia (4.26%), and North America (7.95%). Notably, the prevalence of hip OA increases with age but does not significantly differ between gender.¹

The economic implications of hip OA are considerable. In 2020, an estimated 595 million people were living with OA, representing 7.6% of the global population—a 132.2% increase since 1990. This upward trend is projected to continue with cases of hip OA expected to rise by 78.6% by 2050.²

In the United States, the overall economic impact of OA is estimated at US$136.8 billion annually, with direct medical costs accounting for US$65 billion. This figure has more than doubled over the last decade, surpassing the annual economic costs associated with tobacco-related health effects, cancer, and diabetes.³ These trends underscore the escalating importance of effective management strategies for hip OA to mitigate its impact on individuals and healthcare systems globally. The role of intra-articular hyaluronic acid (IA-HA) in knee OA is well-established. However, its application in hip OA has been more controversial due to anatomical challenges and variability in clinical outcomes.

The EUROVISCO (European Viscosupplementation Consensus Group) is a multidisciplinary panel of European experts specializing in OA management established to develop evidence-based guidelines for viscosupplementation (VS).⁴ The group has focused on optimizing the use of IA-HA in different OA joints.^5,6

The present set of recommendations aims to update statements on the role of VS in hip OA management, based on the latest evidence-based medical data and expert opinion.

Methods

Experts: The EUROVISCO working group comprises 12 health care professionals and researchers from eight European countries, including, Belgium, the United Kingdom, France, Italy, Portugal, Spain, Sweden, and Turkey, joined by a guest expert from Brazil. This panel of 12 experts includes five rheumatologists, three orthopedic surgeons, two rehabilitation specialists, one specialist in sport medicine and one interventional radiologist. All members are experts in OA treatment, with a particular focus on VS and clinical research methodology. The group represents various medical settings, including private practices, public hospitals, and university hospitals.

The group convened in Lyon on September 19 and 20, 2024. Nine members attended in person, whilst three participated remotely. Since its inception in 2014, the group has designated one member as the chairperson for each meeting. The chairperson facilitates discussions, moderates debates, and resolves differences of opinion among members.

The working session was divided into two parts. In the first session, the four working group members (TC, YH, DD, and AM) were tasked with carrying out a comprehensive literature review on four key topics (by conducting an in-depth literature review, analyzing several databases and selecting the most relevant publications in their field of interest) and present it to the panel of experts on the following topics: (a) Current level of evidence in hip VS, (b) Italian experience in hip VS, (c) Treatment of hip OA with IA corticosteroid injection, and (d) platelet-rich plasma (PRP) for the treatment of hip OA.

The second session was devoted to discussion and voting on 24 statements concerning VS of the hip. Each issue was subjected to a vote using a 9-point numeric scale: scores 1 to 3 indicated disagreement (“I disagree”), score 1 meant “I fully disagree,” scores 4 to 6 reflected conditional agreement (“I agree, but only under specific conditions”), scores 7 to 9 signified agreement (“I agree in the majority of cases”) and score 9 meant full agreement.

Voting was conducted using interactive software (Quizzbox^©, Clermont-Ferrand, France), which provided real-time results for the group and individual members. The software calculated a median agreement score for each question, with recommendations categorized as follows:

Strong in favor: Median score of 9 or 8.

Moderate in favor: Median score of 7.

Weak in favor: Median score of 6.

No possible recommendation: 5.

Weak Against: Median score of 4.

Moderate Against: Median score of 3.

Strong Against: Median score of 1 or 2.

The level of consensus was determined based on the number of experts assigning similar scores to each issue:

Unanimous: All 12 experts share the same opinion.

High: 11 or 10 experts share the same opinion.

Moderate: 9 experts share the same opinion.

Low: 8 or 7 share the same opinion.

No consensus: 6 or fewer experts share the same opinion.

After each recommendation, the group discussed the results. Members shared their perspectives, including dissenting opinions, and attempted to reach a unified consensus. If necessary, a new vote was conducted at the request of any member wishing to amend their initial response. The debates were recorded in their entirety to allow the authors of the article to refer to the arguments of the protagonists.

Results

From Literature Research

The literature research includes six meta-analyses, four systematic reviews, and 14 observational studies evaluating IA-HA for hip OA.

Meta-Analyses

In 2016, Piccirilli et al.⁷ included 26 articles reporting a lack of standardization of HA injections for hip conditions. They also suggested that IA-HA is the best conservative therapy before surgery, as it can act on pain relief and function. However, there was no evidence to prove its ability to modify the morphological structure of the pathological hip and the natural history of the disease. In 2018, Leite et al.⁸ found no significant difference between HA and placebo in terms of pain relief at 3 months and no superiority over corticosteroids in short-term symptom relief. Liao et al.⁹ included only five high-quality randomized controlled trials (RCTs) in their meta-analysis. They found that IA-HA did not significantly reduce pain or improve function compared with placebo, highlighting the need for better-designed trials. Wu et al.¹⁰ published in 2021 a meta-analysis of 15 studies and concluded that high molecular weight (HMW) HA showed superior pain relief and functional improvement at 3 and 6 months compared with lower molecular weight HA. The same year, Ebad Ali et al.¹¹ in a systematic review analyzed the efficacy of only intra-articular HMW HA for hip OA including four studies comprising 185 and 189 patients in HMW HA and control groups. Although intra-articular HMW HA injection provided pain relief and functional improvement, the results did not favor treatment with HMW HA over other treatment methods. Patel et al.¹² in 2024 discussed a meta-analysis of 4 high-quality RCTs assessing HMW HA and found no statistically significant difference in pain reduction or functional improvement (Lequesne Index) compared with placebo or other treatments. However, it confirmed the safety of HA, with no increased risk of adverse events.

Systematic review

In a systematic review, Acuña et al.¹³ found that HA improved patient-reported outcome measures but was not consistently superior to placebo or other intra-articular treatments in 39 studies involving 5864 patients. The authors outlined that there was considerable variation across studies regarding HA formulations, injection schedules, and postinjection protocols. Vilabril et al.¹⁴ in the same year compared three studies on the clinical effect between IA injections of corticosteroids and HA in hip OA, showing heterogeneity in the type of population, number of injections and formulation of HA VS. The analyzed studies had a short follow-up time. The results obtained seem to demonstrate the superiority of steroids compared with HA in managing pain, namely, in the onset of clinical response. Ferrara et al.¹⁵ analyzed 12 RCTs including eight papers comparing HA and PRP or corticosteroids and saline solution, one paper comparing two types of HA with different MW and finally, three papers studying the effects of corticosteroids alone or compared with ketorolac or saline solution. The studies reviewed were heterogeneous regarding sample size, OA severity evaluated by and follow-up timings. However, IA injections of PRP seem to decrease pain in the short term and the disability in the long term more effectively than HA. The assumption was that administering HA and corticosteroids simultaneously could yield better results than administering HA alone. On the contrary, Zhu et al.¹⁶ in a systematic review of 40 studies (3,350 patients) reported improvements in pain and function at 1, 3, and 6-months postinjection. However, high heterogeneity, low evidence levels, and bias limited the strength of conclusions. However, subgroup analyses of the effects of dose, volume, composition of VS, and number of injections seemed to compliment the primary findings. The most recent systematic review was published by Migliorini et al.¹⁷ in 2025. All the RCTs evaluating the efficacy of IA-HA injections in the hip for OA were included. Nine hundred and eighty-two patients were analyzed. Patients receiving HMW-HA and medium molecular weight (MMW) HA showed significant improvements in Western Ontario and McMaster Universities (WOMAC) score. No significant differences in patients’ reported outcomes (PROs) were observed among groups at 3 to 4 months of follow-up. However, at 4 to 6 months, the HMW-HA group exhibited significantly lower pain scores compared with the other treatment groups. At 4 to 6 months, both HA performed better than the control group (P < .0001), but no significant difference was observed between HAs according to the MW (P = 1.0). The authors concluded that IA-HA effectively reduce hip OA symptoms.

Key findings from observational studies

A long-term follow-up study published in 2017 by Migliore et al.¹⁸ reported the efficacy of US-guided HA (4 ml) injections, administered at least twice a year for up to 7 years, involving 1022 patients with hip OA. Regardless of age or body mass index (BMI), all patients experienced significant improvements in assessment scores for 6 months posttreatment, with repeated HA injections maintaining these improvements up to 7 years. No systemic or severe local side effects were reported over 7 years affirming previous data.^19,20 The same authors confirmed the property of hip VS to reduce painkiller consumption.²¹ De Lucia et al.²¹ observed symptom improvement with IA-HA over 2 years in patients with both primary OA or secondary OA to inflammatory rheumatic diseases. These data also suggested that repeated administrations are safe and can achieve an additive effect. Several studies with different lengths of follow-up and patient sample sizes between 2017 and 2024 have shown similar results, reporting that subjects with a moderate grade of OA (Kellgren–Lawrence K-L-grade 2) represent the group that could benefit the most with VS.^22
-27 In active sportsmen, clinical benefits were reported after hip VS.²⁸ Letizia Mauro et al.²⁹ in 2017 demonstrated in 40 treated patients that the effects of the HA enabled patients to comply better with the rehabilitation therapy, synergizing the two therapeutic effects. It could be suggested that patients suffering from hip OA seem to benefit from VS and concurrent exercise therapy.

Voting Statements

The statements that achieved unanimous or high consensus are displayed in Table 1.

Table 1.

Statements on Hip Viscosupplementation Achieving Unanimous or High Level of Consensus.

Statement	Agreement	Level of Consensus	Level of Evidence³⁰
The current hindsight in its use and the results of observational studies make the use of VS legitimate in patients suffering from hip OA not requiring surgery.	Strong in favor	Unanimous	2a
The anatomical characteristics of the hip (radiological grade and pattern of femoral head migration) should be taken into account before considering VS	Strong in favor	High	2b
Recent standard X-rays (less than 3-month-old), with at least 2 radiological views are essential before considering VS of the hip	Strong in favor	Unanimous	5
To ensure accurate needle positioning, hip VS should be performed under imaging guidance (ultrasound or fluoroscopy)	Strong in favor	Unanimous	2a
The outcomes of VS vary according to the viscosupplements characteristics	Strong in favor	High	2b
A single injection regimen, with a viscosupplement specifically dedicated to this purpose, should be preferred to a multiple injection regimen in hip VS	Strong in favor	Unanimous	5
In hip VS, it is recommended to use only viscosupplements that have demonstrated their efficacy/safety in clinical trials	Weak in favor	Unanimous	5
VS is more effective in mild to moderate than in severe hip OA	Strong in favor	Unanimous	1b
VS can be considered in patients with severe hip OA wishing to postpone hip prosthesis or with a contraindication to surgery, provided that they are properly informed about the low chances of success	Moderate in favor	High	5
VS can be considered in symptomatic early hip OA (normal X-rays, evidence of OA on MRI or CT arthrography).	Strong in favor	High	5
In case of acute hip OA flare with joint effusion, it is preferable to inject a corticosteroid rather than VS.	Strong in favor	Unanimous	2a
Hip VS is part of a multimodal treatment that must include other therapeutic modalities (rehabilitative and/or pharmacological measures).	Strong in favor	Unanimous	5
The time interval between 2 applications depends on the clinical conditions and the wishes of the patient.	Strong in favor	High	5
Viscosupplement injections can be repeated, if necessary, every 6 to 12 months, as long as they are effective, without any limit on the number.	Strong in favor	High	2b
It is recommended to perform an IA injection of corticosteroids at the time of VS to improve the results of the latter.	Strong against	High	5
If arthroplasty is planned, it is recommended not to perform VS for at least 3 months before surgery.	Strong in favor	Unanimous	2b
VS can be considered in mild OA due to femoroacetabular impingement	Strong in favor	Unanimous	2b
Hip VS is safe and well tolerated, even in case of repeated injections.	Strong in favor	Unanimous	1a

Statement 1: The Current Hindsight in Its Use and the Results of Observational Studies Make the Use of VS Useful in Patients Suffering from Hip OA Not Requiring Surgery

Mean (SD) 8.3 (0.6); Min-max 7-9; median 9

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: The experts initially expressed only moderate support with a low level of consensus for the assertion that “the actual Evidence Based Medicine is sufficient to include VS in the management of hip OA.” While some considered the evidence sufficiently robust, others argued that, based solely on the available randomized clinical trials and meta-analyses whose results are conflicting, the evidence remains insufficient to strongly warrant including VS in clinical recommendations for managing hip OA. After a comprehensive debate with this second formulation—“the current hindsight in its use and the results of observational studies make the use of VS useful in patients suffering from hip OA not requiring surgery”—the statement achieved unanimous approval with a high level of agreement. Indeed, numerous open-label studies and years of clinical practice have demonstrated that many patients with hip OA experience significant and enduring benefits from VS.^22
-27

Statement 2: VS Can Reduce Pain and Improve Function and Quality of Life in Patients with Hip OA for Several Months

Mean (SD) 6.7 (2.1); Min-max 2-9; Median 7

Agreement: Weak in favor

Level of consensus: moderate (9/12)

Comment: While the large majority of experts concurred that VS can sustainably alleviate pain and improve function and quality of life in patients with hip OA, the overall degree of agreement was only “moderate,” indicating that the expected improvement is generally moderate and depends on multiple factors, including the severity of OA and the type of femoral head migration.

Statement 3: The Anatomical Characteristics of the Hip (Radiological Grade and Pattern of Femoral Head Migration) Should Be Taken into Account before Considering VS

Mean (SD) 7.6 (2.3); Min-max 2-8; Median 8

Agreement: Strong in favor

Level of consensus: High (10/12)

Comment: Drawing on the work of Eymard et al.,³¹ which highlighted the influence of anatomical severity and architectural factors on the outcomes of hip VS, most experts supported this proposal.

Statement 4: Recent Standard X-Rays (Less than 3 Months Old), with at least Two Radiological Views, Are Essential before Considering VS of the Hip

Mean (SD) 8.5 (0.7); Min-max 7-9; Median 9;

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: Unsurprisingly, all experts considered that a recent standard hip X-ray was essential before proposing hip VS. The recommended radiological views are an anteroposterior pelvic view and a Lequesne false profile,³² both taken in a standing position. In cases of femoroacetabular impingement, a Dunn 45° view³³ is also necessary.

Statement 5: A Recent MRI Can Be Helpful before Considering VS of the Hip

Mean (SD) 6.4 (2.4); Min-max 2-9; Median 6

Agreement: Weak in favor

Level of consensus: low (8/12)

Comment: This statement received only a low level of agreement, as experts considered that MRI is generally not essential to make OA diagnosis and to decide treatment with VS despite Deseyne et al.³⁴ demonstrated that hip inflammation MRI scoring system (HIMRISS) was highly predictive of VS outcome. They suggest making decisions on a case-by-case basis when there is a clinico-radiological discrepancy, especially when the level of pain cannot be explained solely by the radiological findings (e.g., minimal joint space narrowing with severe pain) and differential diagnosis is necessary to discriminate hip osteonecrosis or bursitis and/or tendon involvement.³⁵

Statement 6: To Ensure Accurate Needle Positioning, Hip VS should be Performed under Imaging Guidance (Ultrasound or Fluoroscopy)

Mean (SD) 8.9 (0.3); Min-max 8-9; Median 9

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: All experts share the same opinion: imaging guidance is essential as it is the only way to ensure proper needle placement within the joint cavity. Ultrasound-guided IA injection provided superior clinical outcomes compared with landmark-guided IA injection.³⁶ In comparison with fluoroscopy ultrasound has the advantage of not using ionizing radiation. A review shows that ultrasound is as useful as fluoroscopy for injecting contrast material for CT arthrogram and MR arthrogram. However, contrast material was observed in soft tissues in 53.8% of fluoroscopy-guided procedures and Intra-articular gas was observed in 21.9% of ultrasound-guided studies compared with 38.5% in fluoroscopy-guided studies.³⁷

Fluoroscopy is the traditional imaging modality of choice for the hip, though the complexity of the injection requires a referral to a radiologist causing potential delays in care, increasing cost and longer procedure times. The use of ultrasound guidance is increasing globally since it is less expensive and does not require a contrast.³⁸

Statement 7: The Outcomes of VS Vary According to the Viscosupplements Characteristics

Mean (SD) 7.6 (1.2); Min-max 5-8; Median 8

Agreement: Strong in favor

Level of consensus: high (11/12)

Comment: All members of the working group, except one, agreed that the characteristics of the viscosupplement (MW, concentration, viscoelasticity, linear or cross-linked molecular structure) influence clinical outcomes.³⁹ In 2015, EUROVISCO group strongly agreed not to consider HA viscosupplements as a single class due to the wide difference between products.⁵ Hence the results of clinical trials of a particular VS cannot be extrapolated to others.⁴ HAs can be roughly classified according to their MW: low <1 MDa, medium between 1 and 2 MDa, and high >2 MDa. HMW are generally cross-linked products whose MW can exceed 90 MDa. Wu et al.¹⁰ reported that among different MWs of HA for treating hip OA, HMW HA injection demonstrated the best efficacy for up to 6 months after treatment without increased risk of adverse effects.

Statement 8: A Single Injection Regimen, with a Viscosupplement Specifically Dedicated to This Purpose, Should be Preferred to a Multiple Injection Regimen in Hip VS

Mean (SD) 8.3 (0.7); Min-max 7-9; Median 9

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: All experts favor the use of single injection viscosupplements over repeated injections to minimize risks and inconveniences for patients. Moreover, a single-injection regimen must be performed with products specifically developed for this.⁴

Statement 9: In Hip VS, It Is Recommended to Use only Viscosupplements that Have Demonstrated Their Efficacy/Safety in Clinical Trials

Mean (SD) 7.7 (0.9); Min-max 7-9; Median 8

Agreement: Weak in favor

Level of consensus: unanimous (12/12)

Comment: As previously recommended for the treatment of knee OA with HA,⁵ the EUROVISCO group emphasizes that only viscosupplements that have undergone clinical evaluation should be used for the treatment of hip OA.

Statement 10: VS Is More Effective in Mild to Moderate than in Severe Hip OA

Mean (SD) 8.7 (0.4); Min-max 8-9; Median 9

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: Most studies published to date indicate that VS demonstrates greater efficacy in patients with early to moderate hip OA.^40
-43

Eymard et al.³¹ Have confirmed this finding, reporting significantly better outcomes in patients with KL grades 1 and 2 compared with those with grades 3 and 4. As a result, experts have reached a consensus that IA-HA injections are more effective in managing mild to moderate forms of hip OA.

Statement 11: VS Can Be Considered in Patients with Severe Hip OA Wishing to Postpone Hip Prosthesis or with a Contraindication to Surgery, Provided that They Are Appropriately Informed about the Low Chances of Success

Mean (SD) 7.6 (1.1); Min-max 7-9; Median 7

Agreement: Moderate in favor

Level of consensus: high (10/12)

Comment: Despite evidence demonstrating limited efficacy of VS in advanced stages of OA, experts have suggested that it may still be considered for patients with formal contraindications to surgery or for those unwilling or unable to undergo surgical intervention in the short term. However, Conrozier et al.⁴³ have shown that VS is not a viable long-term alternative to surgery.

Statement 12: VS Can Be Considered in Symptomatic Early Hip OA (Normal X-Rays, Evidence of OA on MRI or CT Arthrography)

Mean (SD) 7.8 (2.1); Min-max 2-8; Median 8

Agreement: Strong in favor

Level of consensus: high (11/12)

Comment: Most experts agree that the earlier OA is treated, the higher the likelihood of a successful outcome. This underscores the importance of identifying “early” OA using precise diagnostic criteria, as has been done for the knee. The working group, therefore, concluded that once the diagnosis of hip OA is confirmed through imaging, even if standard radiographs appear normal, VS is a reasonable therapeutic option. Eymard et al.³¹ demonstrated a 100% success rate at 3 months in their cohort of patients with early-stage hip OA.

Statement 13: In Case of Acute Hip OA Flare with Joint Effusion, It Is Preferable to Inject a Corticosteroid Rather than VS

Mean (SD) 9 (0); Min-max 9-9; Median 9

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: This recommendation received unanimous support and the highest rating from all task force members. Additionally, in the absence of contraindications, IA corticosteroids are considered the primary treatment for acute inflammatory flares of OA, of either the hip or the knee.^5,6,44

Statement 14: Hip VS Is Part of a Multimodal Treatment that Must Include Other Therapeutic Modalities (Rehabilitative and/or Pharmacological Measures)

Mean (SD) 8.9 (0.3); Min-max 8-9; Median 9

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: This statement was endorsed by all members of the working group. It is emphasized that HA injections represent only one aspect of hip OA management. They should be integrated into a comprehensive treatment plan that includes non-pharmacological measures (e.g., physical therapy, tailored physical activity, and weight management) and when necessary, pharmacological interventions.

Statement 15: The Time Interval between 2 Applications Depends on the Clinical Conditions and the Wishes of the Patient

Mean (SD) 7.7 (1.6); Min-max 3-9; Median 8

Agreement: Strong in favor

Level of consensus: high (10/12)

Comment: Most experts agreed with this proposal, considering that treatment should be adapted on a case-by-case basis according to the severity of the disability and the patient’s wishes. Mostly of the observational studies report 2 to 3 injection per year according to the symptoms and wishes of patients.⁴⁵

Statement 16: Viscosupplement Injections Can Be Repeated, If Necessary, every 6 to 12 Months, as long as They Are Effective, without Any Limit on the Number

Mean (SD) 7.2 (2.3); Min-max 2-9; Median 8

Agreement: Strong in favor

Level of consensus: high (10/12)

Comment: The Italian experience endorsed this view of the members that systematically repeating the injection every 6 to 12 months is both an effective and well-tolerated protocol.¹⁹

Statement 17: In Case of Failure of a Previous Hip VS, It Is Recommended to Choose Other Treatment Modalities rather than Repeating the VS

Mean (SD) 6.8 (1.7); Min-max 3-9; Median 7

Agreement: Moderate in favor

Level of consensus: low (8/12)

Comment: Only 3 out of 4 experts agreed with this proposal. Those who disagreed pointed out that not all viscosupplements are equally effective and that in the event of failure of a first HA injection, it is acceptable to try another viscosupplement before concluding to abandon VS. It is similar to what we stated in knee by Eurovisco.⁴⁵

Statement 18: Previous (2 to 4 Weeks before VS) IA Injection of Corticosteroid May Potentiate the Effect of Hip VS

Mean (SD) 5.8 (2.6); Min-max 1-9; Median 6

Agreement: Weak in favor

Level of consensus: no consensus (6/12)

Comment: It was not possible to reach a consensus on this issue. Half the group agreed with this assertion, while the other half considered that injecting a corticosteroid a few weeks before VS brought no additional benefit in terms of pain and joint function. No literature data is available on this issue.

Statement 19: It Is Recommended to Perform an IA Injection of Corticosteroids at the Time of VS to Improve the Results of the Latter

Mean (SD) 2.6 (2.2); Min-max 1-9; Median 2

Agreement: Strong against

Level of consensus: High (11/12)

Comment: On the contrary, the experts were virtually unanimous in recommending that corticosteroid injections should not be carried out at the same time as HA injections. An in vitro study has shown that adding a corticosteroid to HA alters its molecular structure and impairs its rheological properties.⁴⁶ Although an uncontrolled study involving 100 patients with mild to moderate hip OA reported symptomatic improvement up to 6 months after a single injection of a HA–triamcinolone combination,⁴⁷ this benefit was not observed in knee OA, where the combination showed no superiority over HA alone.⁴⁸ These findings are consistent with those of another study comparing cross-linked HA with the same product combined with triamcinolone, which found no difference in efficacy between the two treatment modalities at 3 and 6 months.⁴⁹

Statement 20: If Arthroplasty Is Planned, It Is Recommended Not to Perform VS for at least 3 Months before Surgery

Mean (SD) 8.4 (0.6); Min-max 7-9; Median 8

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: Results on the risk of joint sepsis in patients previously injected with HA or corticosteroids differ. However, it appears that the risk of prosthetic joint infection is significantly reduced when a 3-month interval is observed between the last IA injection and arthroplasty. The experts were therefore unanimous in recommending a minimum delay of 3 months between VS and THR.^50,51

Statement 21: The Total Volume of Intra-Articular Fluid Injected Should Be Less than 6 ml

Mean (SD) 7.6 (1.3); Min-max 5-9; Median 7

Agreement: Moderate in favor

Level of consensus: low (8/12)

Comment: Based on their own experience and for reasons of immediate tolerance by the patient, the members of the working group felt that it was preferable to use low volumes (2 to 3 ml) of viscosupplement, although no published data had shown that increasing the volume beyond 5 or 6 ml could have an unfavorable clinical impact since much higher volume has been used in hip capsulitis.⁵² A radiological study to evaluate two different ultrasound-guided injection techniques for MR arthrography of the hip in fifty-nine consecutive patients (21 men, 38 women) showed no difference in pain perception by the patient between the techniques.⁵³ The injected contrast material volume ranged from 8.9 ± 3.4 ml to 11.2 ± 2.9 ml.

Statement 22: VS Can Be Considered in Mild OA due to Femoro-Acetabular Impingement

Mean (SD) 8.0 (0.8); Min-max 7-9; Median 8

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: Femoro-acetabular impingement is a frequent cause of hip OA in young,⁵⁴ often athletic patients, and progresses slowly. Treatment with VS in conjunction with rehabilitation, therefore, seems particularly well suited to avoiding the adverse effects of long-term use of treatments such as NSAIDs. This view perhaps explains why this proposal was unanimously approved. Significant pain reduction and function improvement have been reported by several authors.⁵⁵,⁵⁶,⁵⁷ The review of Khan et al.⁵⁸ suggests that therapeutic relief at 12 months may be achieved, particularly with HA VS and a negative response to preoperative injections may predict poor short-term surgical outcomes.

Statement 23: Hip VS Is Safe and Well Tolerated, even in the Case of Repeated Injections

Mean (SD) 8.4 (0.7); Min-max 7-9; Median 9

Agreement: Strong in favor

Level of consensus: unanimous (12/12)

Comment: After more than 25 years of experience in clinical practice no severe safety alerts have been reported with VS in knee OA.^59,60 The only meta-analysis that reports safety issues with VS in knee OA is that of Pereira et al.,⁶¹ which has been strongly and rightly criticized⁶² and whose results are more than questionable. All EUROVISCO members consider that hip VS is a well-tolerated treatment, even when injections are repeated over several years.¹⁸

Discussion

Although the systematic literature review found several studies on VS in hip OA, it is still difficult to draw practical conclusions on the treatment protocol. While older studies (2008–2019) leaned toward no significant benefit of VS over placebo or corticosteroids, some recent studies (2021–2025) have suggested that specific formulations, particularly HMW HA (10), may offer clinical benefits for up to 6 months, though evidence remains inconsistent. Although some studies suggest that VS may not be superior to a placebo in the short term, non-comparative studies support its efficacy and have established that the treatment is safe with minimal adverse effects. There is clear evidence that IA-HA reduces pain and improves function in certain patients with hip OA, according to both RCTs and real-world data.^16,18,20 Nevertheless, the heterogeneity of studies (due to different HAs, dosing regimens, multiple hip OA phenotypes/patients) makes it impossible to quantify the clinical benefit of hip VS. Several studies suffer from important limitations such as HAs are not optimally used (i.e., single injection of products designed for multiple injections),⁶³ and/or the radiological characteristics of hip OA are not well defined. In mild to moderate hip OA, IA-HA appears to be as effective as corticosteroids in reducing pain in the medium term, but the effect of corticosteroids is more rapid to occur.¹⁵ HMW HAs (cross-linked HAs) might be more effective than low or medium MW HAs.¹⁰ The degree of heterogeneity and risk of bias in these studies suggest that results should be interpreted with caution with ongoing debate regarding appropriate clinical use. Despite this lack of undeniable evidence about the VS HA effectiveness in hip OA, EUROVISCO considers that it is legitimate to use VS HA to treat hip OA in symptomatic patients not requiring hip replacement. This statement is based more on the experts’ long clinical experience than on the level of scientific evidence, as detailed in Table 1.

The present recommendations aim refining indications, dosing regimens, and injection techniques for IA-HA in hip OA: patient selection by confirming that IA-HA is most effective in mild to moderate hip OA and by cautioning that VS is not an alternative to surgery for advanced disease.⁴ The image-guided injection (fluoroscopy or ultrasound) is strongly recommended to ensure accuracy and efficacy. The group’s consensus work provides more precise and more detailed guidance for clinicians about handling hip VS, aiming to improve treatment outcomes and patient satisfaction in hip OA management. Also the Brazilian Consensus Statement⁶² recommended guided injections for hip VS, noting its cost-effectiveness and efficacy, particularly for mild to moderate hip OA resulting in significant pain reduction and functional improvement. Moreover, VS may delay the need for hip replacement surgery, thus making it a valuable option for the treatment of hip OA.²⁰ In this EUROVISCO consensus for the first time, an expert from Brazil joined the EUROVISCO group and participated in the discussions and voted with the group. He presented the Brazilian Consensus Statement On VS Of The Hip (Cobravi-Q) which had published recommendations on the same subject in 2022.⁶⁴ The Canadian Arthroscopy Association reported that although HA has the potential to provide improvements in pain and functional outcomes for up to 6 months in the treatment of hip OA, high-level evidence remains scarce, with significant heterogeneity in available HA products. Therefore, Canadian guidelines cannot recommend for or against the use of HA for hip OA until further high-quality clinical studies become available.⁶⁵

The Italian consensus published by the “The Italian National Institute of Health” as national authority reports that IA injections are helpful for mild to moderate OA of the hip and found that IA injections are suitable for KL grade II/III OA.⁶⁶ The experts of the Italian consensus also believe that HMW HA is considered to be the most appropriate product, and low-MW HA products may be inappropriate. It is noteworthy that a very high percentage of members were in favor of the use of IA injections in low-grade OA (grade 0-I), reflecting a tendency to perform IA injections earlier in the clinical course of OA, as proposed by us in statement no 12. Early intervention with IA-HA injections in hip OA may play a crucial role in both symptom management and functional preservation. Although HA has not been shown to modify disease progression, its early use is associated with improved joint lubrication, reduced inflammation, and delayed reliance on more invasive treatments.⁵ Treating hip OA in its initial stages could help maintain mobility and potentially extend the period before surgical intervention becomes necessary.¹⁹ Moreover, early HA VS could be particularly beneficial for active patients who seek to preserve their quality of life and delay functional decline.⁶⁷ Given the limited regenerative capacity of articular cartilage, early HA treatment could help optimize conservative management strategies and improve long-term outcomes.

The safety issue in hip VS is noteworthy. While HA injections are widely used for knee OA, their safety and efficacy in hip OA require careful consideration due to the anatomical complexity of the hip joint. The most common side effects are transient pain, swelling and stiffness at the injection site, typically resolving within a few days. Studies report a minor adverse event rate ranging from 3% to 10%.⁶⁸,⁶⁹ Although rare (<0.1%), septic arthritis is a potential complication. Strict aseptic technique is essential to minimize this risk.⁶⁸ Due to the deep anatomical location of the hip joint and its proximity to critical neurovascular structures, improper needle placement can lead to extra-articular injection or neurovascular injury. Imaging guidance, such as ultrasound or fluoroscopy, is mandatory to avoid these risks.⁶⁹ Some patients experience transient synovitis or inflammatory reactions following HA injection. This may be associated with the MW of the HA formulation used.³⁰ Data from the registry and post marketing surveillance confirm a clear good safety record in the real world. However, a statistically significant increased risk of prosthetic joint infections in patients with prior history of IA injections within 3 months from injections has been reported. No definitive increased risk was found for the interval time of 6–12months, in which the pooled effect had not reached statistical significance. At 12 months, the RR ratio returned to be in line with the general risk found for the cohort of patients who received intra articular injections at any time.^50,51

Strengths and Limitations of the Study

Among strengths, first this consensus is based on an extensive systematic literature review encompassing multiple meta-analyses, systematic reviews and observational studies ensuring a broad evaluation of available evidence. The panel of experts is multidisciplinary from multiple countries, providing a well-rounded and convincing perspective. The inclusion of observational studies and clinical practice experiences (e.g., long-term follow-up studies) reflects real-world efficacy and safety evaluation and powers the consensus to provide realistic suggestions to clinicians. The multinational and comparative perspectives integrating insights from national and international association highlights global perspectives on hip VS. Finally, the consensus underscores a personalized approach to care. The main limitation is the heterogeneity of studies that vary significantly in terms of HA formulations, injection protocols and patient selection criteria, making conclusions challenging. Moreover, many underlying trials have small sample sizes, short follow-up durations and/or methodological inconsistencies. Real-world studies included in the review may be subject to selection bias, as patients who experience benefits from HA are more likely to continue treatment. Lastly, unfortunately the lack of literature data did not allow us from reaching a conclusion on two key points: the cost-effectiveness of hip viscosupplementation, and whether it can delay the need for prosthetics in certain cases.

If we had to summarize our work in just a few lines and retain only a few take-home messages, they would be as follows: (a) The earlier the treatment is carried out, the greater its effectiveness, prompting us to consider VS at the earliest possible anatomical stage. (b) Do not hesitate to re-treat every 6 to 12 months, as soon as the pain tends to increase again. (c) Repeat imaging regularly, as advanced stages have a poor prognosis. (d) Do not perform VS if there is an inflammatory flare-up or if the MRI shows significant bone marrow edema of the femoral head or acetabulum. (e) Always integrate VS into a multimodal treatment plan that includes physical therapy.^70,71,72 (f) Use a HMW HA viscosupplement to optimize the chances of success.

Conclusions

We believe these recommendations are relevant and important to consider when deciding on treatment for hip OA. However, most of the recommendations are based on expert opinion, as there is very little literature available in this field. There is unanimous agreement that the appropriate indication for VS is the mild to moderate stage of hip OA. From a clinical perspective, HA injection for hip OA may provide short-term pain relief and functional improvement, but results vary depending on molecular weight and patient selection. HMW HA seems to be more effective than lower MW formulations, at least in the first 6 months after injection. This finding suggests that HAs cannot be classified as a single group. Therefore, guidelines should consider this point, as HMW HA may be a potential candidate for conservative treatment in hip OA. Moreover, VS in the hip should be considered as part of a multimodal approach. Nevertheless, many uncertainties remain. Larger, well-designed randomized clinical trials with longer follow-up periods are needed to determine the true long-term benefits, the most effective dosage regimens and products, and which patients are likely to benefit most from treatment. Further research is also required to examine the role of VS in the early stages of hip OA and its potential disease-modifying effects specifically, as well as the cost-effectiveness of the procedure. Pending more conclusive data, in a disease that sorely lacks conservative treatments, VS now appears to be a therapeutic option worth considering in certain cases.

Footnotes

ORCID iDs

Yves Henrotin

Thierry Conrozier

Ethical Approval

This work did not require ethical approval.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of Conflicting Interests

The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: We wish to draw the attention of the Editor to the following facts that may be considered as potential conflicts of interest related to the subject and to significant financial contributions to this work. Alberto Migliore: Received consulting fees from Abbvie, BMS, MSD, Fidia, Sanofi, IBSA, Pfizer, and LABRHA, for national and international studies and courses. Yves Henrotin: Received honorarium from Menarini, Flexion therapeutics, IBSA, Bioiberica, Expansciences, Royal Canin, MagPharm, Pfizer, Fidia, LABRHA, and Tilman SA, Grunenthal, Artialis, Kiomed pharma, Genequine for consultant services. Thierry Conrozier: Received honorarium from MEDAC, and LABRHA for expert and/or speaker and/or consultant services. Xavier Chevalier: Received fees as a Genevrier Board member, Sanofi-Aventis expert, member of the IBSA foundation, speaker in IBSA and LABRHA meetings, and Moebius and Flexion therapist consultant. Jordy Monfort: Received consulting fees from Labrha, Sanofi and Bioiberica. Dominique Baron: Received speaker fees from LABRHA? LCA and Expansciences. Demirhan Diraçoglu: Received speaker fees from LABRHA. Mats Brittberg is a Member Advisory board of: Episurf Medical AB, Xintela AB, Magellan Stem Cells PTY LTD, Cline Scientific AB, Askel Healthcare LTD, Vanarix SA. Participation Speaker’s bureau for Arthrex and for Anika Therapeutics. Member editorial board Osteoarthritis & Cartilage, Editor-in-Chief CARTILAGE. Raghu Raman: Received consulting fees from Labrha. Paulo Cesar Hamdan: Received consulting fees from Labrha. Belarmino Goncalves: None. We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us. We confirm that we have given due consideration to the protection of intellectual property associated with this work and that there are no impediments to publication, including the timing of publication, with respect to intellectual property. In so doing we confirm that we have followed the regulations of our institutions concerning intellectual property.

References

Fan

Yan

Liu

Fan

Liu

, et al. The prevalence of hip osteoarthritis: a systematic review and meta-analysis. Arthritis Res Ther. 2023;25(1):51. doi:10.1186/s13075-023-03033-7.

Wong

Samartzis

Maher

. The global burden of osteoarthritis: past and future perspectives. Lancet Rheumatol. 2023;5(9):e496-7. doi:10.1016/S2665-9913(23)00207-2.

Centers for Disease Control and Prevention. Osteoarthritis. [cited 2025 Jan 29]. Available from: https://www.cdc.gov/arthritis/osteoarthritis/index.html

Conrozier

Raman

Chevalier

Henrotin

Monfort

Diraçoglù

, et al. Viscosupplementation for the treatment of osteoarthritis. The contribution of EUROVISCO group. Ther Adv Musculoskelet Dis. 2021;131759720X211018605. doi:10.1177/1759720X211018605.

Henrotin

Raman

Richette

Bard

Jerosch

Conrozier

, et al. Consensus statement on viscosupplementation with hyaluronic acid for the management of osteoarthritis. Semin Arthritis Rheum. 2015;45(2):140-9. doi:10.1016/j.semarthrit.2015.04.01.

Conrozier

Monfort

Chevalier

Raman

Richette

Diraçoglù

, et al. EUROVISCO recommendations for optimizing the clinical results of viscosupplementation in osteoarthritis. Cartilage. 2020;11(1):47-59. doi:10.1177/1947603518783455.

Piccirilli

Oliva

Murè

Mahmoud

Foti

Tarantino

, et al. Viscosupplementation with intra-articular hyaluronic acid for hip disorders. A systematic review and meta-analysis. Muscles Ligaments Tendons J. 2016;6(3):293-9. doi:10.11138/mltj/2016.6.3.293.

Leite

Daud Amadera

Buehler

. Viscosupplementation for hip osteoarthritis: a systematic review and meta-analysis of the efficacy on pain and disability, and the occurrence of adverse events. Arch Phys Med Rehabil. 2018;99(3):574-83.e1. doi:10.1016/j.apmr.2017.07.010.

Liao

Lin

Zhu

Shi

Yan

. Intra-articular viscosupplementation for patients with hip osteoarthritis: a meta-analysis and systematic review. Med Sci Monit. 2019;25:6436-45. doi:10.12659/MSM.916955.

10.

Huang

Shih

Chen

Cheng

, et al. Molecular weight of hyaluronic acid has major influence on its efficacy and safety for viscosupplementation in hip osteoarthritis: a systematic review and meta-analysis. Cartilage. 2021;13(Suppl 1):169S-184S. doi:10.1177/19476035211021903.

11.

Ebad Ali

Farooqui

Sahito

Ali

Khan

Naeem

. Clinical outcomes of intra-articular high molecular weight hyaluronic acid injection for hip osteoarthritis–a systematic review and meta-analysis. J Ayub Med Coll Abbottabad. 2021;33(2):315-21.

12.

Patel

Orfanos

Gibson

Banks

McConaghie

Banerjee

. Viscosupplementation with high molecular weight hyaluronic acid for hip osteoarthritis: a systematic review and meta-analysis of randomised control trials of the efficacy on pain, functional disability, and the occurrence of adverse events. Acta Chir Orthop Traumatol Cech. 2024;91(2):109-19. doi:10.55095/ACHOT2024/009.

13.

Acuña

Samuel

Jeong

Emara

Kamath

. Viscosupplementation for hip osteoarthritis: does systematic review of patient-reported outcome measures support use? J Orthop. 2020;21:137-49. doi:10.1016/j.jor.2020.03.016.

14.

Vilabril

Rocha-Melo

Gonçalves

Vilaça-Costa

Brito

. Hip osteoarthritis treatment with intra-articular injections: hyaluronic acid versus glucocorticoid–a systematic review. Acta Reumatol Port. 2020;45(2):127-36.

15.

Ferrara

Codazza

Coraci

Malerba

Ferriero

Ronconi

. State of art in intra-articular hip injections of different medications for osteoarthritis: a systematic review. BMC Musculoskelet Disord. 2021;22(Suppl 2):997. doi:10.1186/s12891-021-04866-6.

16.

Zhu

Lim

McCaskie

Khanduja

. Viscosupplementation is effective for the treatment of osteoarthritis in the hip: a systematic review. Arthroscopy. 2024;40(6):1908-22.e13. doi:10.1016/j.arthro.2023.11.010.

17.

Migliorini

Pilone

Mazzoleni

Schäfer

Katusic

Maffulli

. Intra-articular hyaluronic acid injections for hip osteoarthritis: a level I systematic review. Eur J Orthop Surg Traumatol. 2025;35(1):180. doi:10.1007/s00590-025-04292-7.

18.

Migliore

Massafra

Frediani

Bizzi

Sinelnikov Yzchaki

Gigliucci

, et al. HyalOne® in the treatment of symptomatic hip OA–data from the ANTIAGE register: seven years of observation. Eur Rev Med Pharmacol Sci. 2017;21(7):1635-44.

19.

Migliore

Bella

Bisignani

Calderaro

De Amicis

Logroscino

, et al. Total hip replacement rate in a cohort of patients affected by symptomatic hip osteoarthritis following intra-articular sodium hyaluronate (MW 1,500-2,000 kDa) ORTOBRIX study. Clin Rheumatol. 2012;31(8):1187-96. doi:10.1007/s10067-012-1994-4.

20.

Migliore

Granata

Tormenta

Laganà

Piscitelli

Bizzi

, et al. Hip viscosupplementation under ultra-sound guidance riduces NSAID consumption in symptomatic hip osteoarthritis patients in a long follow-up. Data from Italian registry. Eur Rev Med Pharmacol Sci. 2011;15(1):25-34.

21.

De Lucia

Pierannunzii

Pregnolato

Verduci

Crotti

Valcamonica

, et al. Effectiveness and tolerability of repeated courses of viscosupplementation in symptomatic hip osteoarthritis: a retrospective observational cohort study of high molecular weight vs. medium molecular weight hyaluronic acid vs. no viscosupplementation. Front Pharmacol. 2019;10:1007.

22.

Schiavi

Calderazzi

Pedrini

Tacci

Vaienti

Pogliacomi

. Efficacy and safety of viscosupplementation with hyaluronic acid for hip osteoarthritis: results from a cross-sectional study with a minimum follow-up of 4 years. Acta Biomed. 2020;91(14-S):e2020032. doi:10.23750/abm.v91i14-S.11110.

23.

Battaglia

D’Apolito

Labionda

Ramazzotti

Zagra

. Ultrasound-guided hip injections with high density hyaluronic acid: outcome at one year follow up. J Clin Med. 2024;13(9):2515. doi:10.3390/jcm13092515.

24.

Migliore

Frediani

Gigliucci

Foti

Crimaldi

De Lucia

, et al. Efficacy of a single intra-articular HYMOVIS ONE injection for managing symptomatic hip osteoarthritis: a 12-month follow-up retrospective analysis of the ANTIAGE register data. Orthop Res Rev. 2020;12:19-26. doi:10.2147/ORR.S239355.

25.

Conrozier

Couris

Mathieu

Merle-Vincent

Piperno

Coury

, et al. Safety, efficacy and predictive factors of efficacy of a single intra-articular injection of non-animal-stabilized-hyaluronic-acid in the hip joint: results of a standardized follow-up of patients treated for hip osteoarthritis in daily practice. Arch Orthop Trauma Surg. 2009;129(6):843-8. doi:10.1007/s00402-008-0778-4.

26.

Migliore

Massafra

Bizzi

Tormenta

Cassol

Granata

. Duration of symptom relief after intra-articular injection of hyaluronic acid combined with sorbitol (anti-ox-vs) in symptomatic hip osteoarthritis. Int J Immunopathol Pharmacol. 2014;27(2):245-252D. doi:10.1177/039463201402700211.

27.

Spoto

Midiri

Letizia Mauro

. Hybrid hyaluronic acid versus high molecular weight hyaluronic acid for the treatment of hip osteoarthritis in overweight/obese patients. J Funct Morphol Kinesiol. 2022;7(1):20. doi:10.3390/jfmk7010020.

28.

Rando

Pastorino

. Intra-articular HYMOVIS injection for managing hip OA in active sportsmen. A 24-month observational retrospective clinical investigation. J Clin Orthop Trauma. 2021;22:101594. doi:10.1016/j.jcot.2021.101594.

29.

Mauro

Sanfilippo

Scaturro

. The effectiveness of intra-articular injections of Hyalubrix® combined with exercise therapy in the treatment of hip osteoarthritis. Clin Cases Miner Bone Metab. 2017;14(2):146-52. doi:10.11138/ccmbm/2017.14.1.146.

30.

OCEBM Levels of Evidence Working Group. The Oxford 2011 levels of evidence. Howick J, Iain Chalmers (James Lind Library), Paul Glasziou et al. Oxford Centre for Evidence-Based Medicine. [cited 2025 Nov 10]. Available from: http://www.cebm.net/index.aspx?o=5653

31.

Eymard

Maillet

Lellouche

Mellac Ducamp

Brocq

Loeuille

, et al. Predictors of response to viscosupplementation in patients with hip osteoarthritis: results of a prospective, observational, multicentre, open-label, pilot study. BMC Musculoskelet Disord. 2017;18(1):3. doi:10.1186/s12891-016-1359-2.

32.

Lequesne

. The false profile view of the hip: role, interest, economic considerations. Joint Bone Spine. 2002;69(2):109-13. doi:10.1016/s1297-319x(02)00358-5.

33.

Mascarenhas

Castro

Rego

Sutter

Sconfienza

Kassarjian

, et al. The Lisbon agreement on femoroacetabular impingement imaging-part 1: overview. Eur Radiol. 2020;30(10):5281-5297. doi:10.1007/s00330-020-06822-9. Epub 2020 Jul 17. Erratum in: Eur Radiol. 2020;30(12):6966-7. doi:10.1007/s00330-020-07009-y.

34.

Deseyne

Conrozier

Lellouche

Maillet

Weber

Jaremko

, et al. Hip Inflammation MRI Scoring System (HIMRISS) to predict response to hyaluronic acid injection in hip osteoarthritis. Joint Bone Spine. 2018;85(4):475-80. doi:10.1016/j.jbspin.2017.08.004.

35.

Sofat

Howe

. Bone marrow lesions in osteoarthritis: characterising genetic and histological changes to understand disease pathophysiology. Osteoarthritis Cartilage Open. 2024;6(4):100531. doi:10.1016/j.ocarto.2024.100531.

36.

Linklater

Siddiq

MAB

Hunter

. Comparison of ultrasound guidance with landmark guidance for symptomatic benefits in knee, hip and hand osteoarthritis: systematic review and meta-analysis of randomised controlled trials. Australas J Ultrasound Med. 2024;27(2):97-105. doi:10.1002/ajum.12386.

37.

Martínez-Martínez

García-Espinosa

Ruiz-Santiago

Guzmán-Álvarez

Castellano-García

. Comparison of ultrasound and fluoroscopic guidance for injection in CT arthrography and MR arthrography of the hip. Radiologia. 2016;58(6):454-9. doi:10.1016/j.rx.2016.07.006.

38.

Saha

Smith

Hasan

. Accuracy of intraarticular injections: blind vs. image guided techniques–a review of literature. J Funct Morphol Kinesiol. 2023;8(3):93. doi:10.3390/jfmk8030093.

39.

Altman

Bedi

Karlsson

Sancheti

Schemitsch

. Product differences in intra-articular hyaluronic acids for osteoarthritis of the knee. Am J Sports Med. 2016;44(8):2158-65. doi:10.1177/0363546515609599.

40.

Pogliacomi

Schiavi

Paraskevopoulos

Leigheb

Pedrazzini

Ceccarelli

, et al. When is indicated viscosupplementation in hip osteoarthritis? Acta Biomed. 2018;90(1-S):67-74.

41.

Schiavi

Calderazzi

Pedrini

Tacci

Vaienti

Pogliacomi

42.

Conrozier

Vignon

. Is there evidence to support the inclusion of viscosupplementation in the treatment paradigm for patients with hip osteoarthritis? Clin Exp Rheumatol. 2005;23(5):711-6.

43.

Conrozier

Bossert

Balblanc

Sondag

Walliser-Lohse

. Viscosupplementation with HANOX-M-XL is effective in moderate hip osteoarthritis but is not an alternative to hip joint surgery in patients with severe disease. Results of a clinical survey in 191 patients treated in daily practice. EJMD. 2014;3(2):49-55.

44.

Conrozier

Diraçoglù

Monfort

Chevalier

Bard

Baron

, et al. EUROVISCO good practice recommendations for a first viscosupplementation in patients with knee osteoarthritis. Cartilage. 2023;14(2):125-35. doi:10.1177/19476035221138958.

45.

Raman

Henrotin

Chevalier

Migliore

Jerosch

Montfort

, et al. Decision algorithms for the retreatment with viscosupplementation in patients suffering from knee osteoarthritis: recommendations from the EUROpean VIScosupplementation COnsensus Group (EUROVISCO). Cartilage. 2018;9(3):263-75. doi:10.1177/1947603517693043.

46.

Conrozier

Patarin

Mathieu

Rinaudo

. Steroids, lidocain and ioxaglic acid modify the viscosity of hyaluronic acid: in vitro study and clinical implications. Springerplus. 2016;5:170. doi:10.1186/s40064-016-1762-z.

47.

Prospective Evaluation of the Cingal™ Injection for Hip Osteoarthritis (ECHO) Investigators. Intra-articular injection of a cross-linked hyaluronic acid combined with triamcinolone hexacetonide improves pain at six months in patients with mild to moderate hip osteoarthritis: a prospective observational study. J ISAKOS. 2025;10:100363. doi:10.1016/j.jisako.2024.100363.

48.

Hangody

Szody

Lukasik

Zgadzaj

Lénárt

Dokoupilova

, et al. Intraarticular injection of a cross-linked sodium hyaluronate combined with triamcinolone hexacetonide (cingal) to provide symptomatic relief of osteoarthritis of the knee: a randomized, double-blind, placebo-controlled multicenter clinical trial. Cartilage. 2018;9(3):276-83. doi:10.1177/1947603517703732.

49.

de Campos

Rezende

Pailo

Frucchi

Camargo

. Adding triamcinolone improves viscosupplementation: a randomized clinical trial. Clin Orthop Relat Res. 2013;471(2):613-20. doi:10.1007/s11999-012-2659-y.

50.

Saracco

Ciriello

D’Angelo

Zagra

Solarino

Logroscino

. Do prior intra-articular injections impact on the risk of periprosthetic joint infection in patients undergoing total hip arthroplasty? a meta-analysis of the current evidences with a focus on the timing of injection before surgery. EFORT Open Rev. 2023;8(6):459-67. doi:10.1530/EOR-23-0028.

51.

Colen

Hoorntje

Maeckelbergh

van Diemen

Dalemans

van den Bekerom

MPJ

, et al. Intra-articular hyaluronic acid injections less than 6 months before total hip arthroplasty: is it safe? a retrospective cohort study in 565 patients. J Arthroplasty. 2021;36(3):1003-8. doi:10.1016/j.arth.2020.09.024.

52.

Yoon

Shim

Lee

Sung

Choo

. Ultrasound-guided hydrodilatation for adhesive capsulitis of the hip is a safe and effective treatment. Int Orthop. 2021;45(6):1455-61. doi:10.1007/s00264-020-04909-y.

53.

Kantarci

Ozbayrak

Gulsen

Gencturk

Botanlioglu

Mihmanli

. Ultrasound-guided injection for MR arthrography of the hip: comparison of two different techniques. Skeletal Radiol. 2013;42(1):37-42. doi:10.1007/s00256-011-1306-0.

54.

Zhang

Tian

. Current understanding of articular cartilage lesions in femoroacetabular impingement syndrome. J Orthop Surg Res. 2024;19(1):886. doi:10.1186/s13018-024-05322-6.

55.

Abate

Scuccimarra

Vanni

Pantalone

Salini

. Femoroacetabular impingement: is hyaluronic acid effective? Knee Surg Sports Traumatol Arthrosc. 2014;22(4):889-92. doi:10.1007/s00167-013-2581-1.

56.

Lee

Kang

. Intra-articular injections in patients with femoroacetabular impingement: a prospective, randomized, double-blind, cross-over study. J Korean Med Sci. 2016;31(11):1822-7. doi:10.3346/jkms.2016.31.11.1822.

57.

Ometti

Schipani

Conte

Pironti

Salini

. The efficacy of intra-articular HYADD4-G injection in the treatment of femoroacetabular impingement: results at one year follow up. J Drug Assess. 2020;9(1):159-66. doi:10.1080/21556660.2020.1843860.

58.

Khan

Alradwan

Williams

Simunovic

Ayeni

. Utility of intra-articular hip injections for femoroacetabular impingement: a systematic review. Orthop J Sports Med. 2015;3(9):2325967115601030. doi:10.1177/2325967115601030.

59.

Strand

McIntyre

Beach

Miller

Block

. Safety and efficacy of US-approved viscosupplements for knee osteoarthritis: a systematic review and meta-analysis of randomized, saline-controlled trials. J Pain Res. 2015;8:217-28. doi:10.2147/JPR.S83076.

60.

Maheu

Bannuru

Herrero-Beaumont

Allali

Bard

Migliore

. Why we should definitely include intra-articular hyaluronic acid as a therapeutic option in the management of knee osteoarthritis: results of an extensive critical literature review. Semin Arthritis Rheum. 2019;48(4):563-72. doi:10.1016/j.semarthrit.2018.06.002.

61.

Pereira

Saadat

Bobos

Iskander

Bodmer

Rudnicki

, et al. Effectiveness and safety of intra-articular interventions for knee and hip osteoarthritis based on large randomized trials: a systematic review and network meta-analysis. Osteoarthritis Cartilage. 2025;33(2):207-17. doi:10.1016/j.joca.2024.08.014.

62.

Richette

Ravaud

Conrozier

Euller-Ziegler

Mazières

Maugars

, et al. Effect of hyaluronic acid in symptomatic hip osteoarthritis: a multicenter, randomized, placebo-controlled trial. Arthritis Rheum. 2009;60(3):824-30. doi:10.1002/art.24301.

63.

Sousa

Hamdan

Menegassi

ZJB

Alchaar

AADA

Tieppo

Souza

, et al. Brazilian consensus statement on viscosupplementation of the hip (COBRAVI-Q). Acta Ortop Bras. 2022;30(5):e250414.

64.

Barbara

Ritchie

Severn

. Intra-articular hyaluronic acid for osteoarthritis of the hip, shoulder, and ankle: rapid review. Ottawa (ON): Canadian Agency for Drugs and Technologies in Health. Mar. Report No.: RC1528. 2024.

65.

Paoloni

Bernetti

Belelli

Brignoli

Buoso

Caputi

, et al. Appropriateness of clinical and organizational criteria for intra-articular injection therapies in osteoarthritis. A Delphi method consensus initiative among experts in Italy. Ann Ist Super Sanita. 2015;51(2):131-8.

66.

Migliore

Tormenta

Massafra

Alessandri

Martin

. Safety of intra-articular hyaluronic acid injections in the osteoarthritic hip: a literature review. Exp Ther Med. 2012;4(1):130-40.

67.

McCabe

Parkes

Maricar

Hutchinson

Arden

. Safety and efficacy of intra-articular therapies in hip osteoarthritis: a systematic review and meta-analysis. Rheumatology. 2021;60(6):2717-31.

68.

Davis

Hummer

Spritzer

Guermazi

. Ultrasound-guided intra-articular hip injections: efficacy and safety considerations. Skelet Radiol. 2019;48(5):715-26.

69.

Henrotin

Lambert

Richette

Chevalier

. Importance of assessing the molecular weight of hyaluronic acid for viscosupplementation in osteoarthritis: a literature review. Curr Rheumatol Rep. 2015;17(6):59.

70.

Migliore

Massafra

Bizzi

Lagana

Germano

Piscitelli

, et al. Intra-articular injection of hyaluronic acid (MW 1,500-2,000 kDa; HyalOne) in symptomatic osteoarthritis of the hip: a prospective cohort study. Arch Orthop Trauma Surg. 2011;131(12):1677-85.

71.

Veronese

Cooper

Bruyère

Al-Daghri

Branco

Cavalier

, et al. Multimodal multidisciplinary management of patients with moderate to severe pain in knee osteoarthritis: a need to meet patient expectations. Drugs. 2022;82(13):1347-55. doi:10.1007/s40265-022-01773-5.

72.

Bian

Zhao

Zhang

. Comparative efficacy of platelet-rich plasma injection vs ultrasound-guided hyaluronic acid injection in the rehabilitation of hip osteoarthritis: an observational study. Ann Med. 2025;57(1):2524091. doi:10.1080/07853890.2025.2524091.