Intra-articular steroid injection (IAST) proved to be a safe, efficacious, and well tolerated therapy for pain management in hip osteoarthritis patients.

Hip osteoarthritis (OA) is one of the most common and prevalent articular diseases, causing pain and functional disability in patients. It involves major structural changes of the joint which may have a substantial impact on ability to perform daily activities and quality of life. Various treatment methods including surgical and non surgical interventions are used to reduce pain and restore function in patients with hip OA. Patients undergoing surgical treatment with total hip arthroplasty (THA) might need a revision surgery in future. The use of non surgical interventions before surgery to reduce pain may help to avoid revision surgery in these days.

The use of intra-articular steroid therapy (IAST) is also evolving as a potential therapy to reduce pain in OA patients. However, the recommended use of IAST in hip patients is still controversial due to lack of studies evaluating long term efficacy of IAST. A previous systematic review reported the efficacy of IAST in hip OA patients, but it included only five studies with 346 patients and shorter follow up period, indicating the need to determine the efficacy of IAST in long term.

Rationale behind research:

Previous literature is unclear about the long term efficacy of IAST in hip OA patients and potential factors such as the injection dose, the severity of OA, or other predictors that may affect the clinical outcomes. Therefore, the current systematic review was conducted.

Objective:

To determine the efficacy, safety and tolerability of IAST for hip OA patients and discuss the duration and impact of influential factors on IAST efficacy

Literature search:

A systematic search was conducted using online databases such as Medline, EMBASE, and Web of Science. Articles were searched from inception to May 2019 using the keywords “hip oste- oarthritis AND intra-articular injection AND steroids OR methylprednisolone OR triamcinolone OR betamethasone. The search included all non-controlled clinical trials, randomized controlled trials (RCTs), cohort studies, case-control studies and references of review articles to access the other available studies and reduce possible omission.

Inclusion and exclusion criteria:

Inclusion criteria: This systematic review included studies which comprise:

• Patients suffering from pain caused by hip OA, diagnosed using ACR criteria or radiographic evidences
• Intervention groups in which patients received IAST
• IAST and placebo groups in RCTs or IAST groups with different regimes in non-controlled trials
• Patients reporting usable pain reduction outcomes

Exclusion criteria:  Animal studies, protocols or reviews and studies without useful data were excluded

Study selection:

Two reviewers (LXY and LJF) independently screened titles and abstracts and removed duplicate and ineligible studies. For each potentially eligible study, another two reviewers (ZSQ and LXY) examined qualification criteria by reading full articles. In cases of disagreements, a decision was made by discussion.

Quality assessment:

Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence was used to rate the quality of included studies whereas the overall quality of evidences was rated using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

Data Extraction and Analysis:

Common demographics data such as patients’ age and gender, study design, sample sizes of intervention and control groups was extracted under standardized form. Outcome data was extracted at baseline; short term (1-2 weeks, 3–4 weeks) and long term (8-12 weeks) follow up points.

The efficacy measure was converted as standardized mean differences and pooled for above mentioned three time intervals. Review Manager (RevMan 5.3) software was used to generate forest plots of meta-analysis graphs. The heterogeneity of included RCTs was evaluated by the χ2 test. The ratio of the consistency among included studies was calculated using the inconsistency I2 formula. Random-effects model was used to combine different study outcomes when the I2 value was over 50%. Sensitivity and meta regression analysis was not performed.

Study Outcomes:

• The primary outcome was assessment of pain scores after the IASP treatment
• Other study outcomes included impact of influential factors such as such as the injection dose, the severity of OA, or other predictors on pain outcomes and adverse events of IAST

Outcomes:

Study characteristics:  Among 12 included trials, 5 were RCT's and 7 were non controlled trials

Study quality: The quality of 5 RCT's was considered level 2, whereas among 7 non controlled trials, three cohort trials were rated level 3, three case series trials were rated level 4 and one observational trial rated level 2

Effect of intervention on outcome:

• There was a significant reduction in hip pain, which persisted up to 12 weeks after IAST
• The impact of radiographic severity of OA, severity of synovitis, dose of steroids, and injection dose or volume on the clinical outcome of IAST was not significant
• No serious adverse effects were observed and IAST was found to be safe and well tolerated I the most hip OA patients
  

The clinical evidences from the present review demonstrated the significant efficacy of IAST injection on both immediate and delayed pain relief until 12 weeks. The longer follow up data of 12 weeks is reported, which is lacking in previous studies. Also, the potential impact of influential factors on the efficacy of IAST is also discussed, which is rarely reported in any of the previous systematic reviews. Safety and tolerability analysis indicated only a few participants reported side effects. Most fluoroscopic or ultrasound-guided hip IAST procedures were well tolerated among patients.

Guidelines provided by Osteoarthritis Research Society International (OARSI) recommended the use of IAST in patients suffering from moderate-severe pain, local inflammation and those who do not respond to oral analgesic/anti-inflammatory agents satisfactorily. The severity of OA and response to oral medication should be considered before applying IAST for most patients.