A single ultrasound-guided intra-articular hip injection of corticosteroid plus local anaesthetic can provide lasting pain relief in hip osteoarthritis, according to a new study led by researchers from Keele University and published in The BMJ. The injection offers superior relief to current standard care, the authors said.
Although previous trials have shown some benefit from intra-articular steroid injection in hip osteoarthritis, the clinical and economic evidence supporting it is limited and conflicting. Hence at present, the practice is recommended for knee osteoarthritis but generally not for hip osteoarthritis.
National Institute for Health and Care Excellence (NICE) guidelines advise education, exercise, and weight reduction as core treatments. Intra-articular corticosteroid injection is recommended only as an adjunct if pain is moderate to severe.
"Patients with hip osteoarthritis are typically treated in primary care for several years before surgical referral, with evidence suggesting that primary care management is suboptimal," the authors said.
Therefore, they set out to compare the clinical effectiveness of best current treatment (BCT) alone versus BCT combined with ultrasound-guided intra-articular hip injection of either triamcinolone plus lidocaine or lidocaine alone.
BCT comprised written information, a bespoke leaflet on exercise and functional activities, and personalised advice about weight loss, exercise, footwear, walking aids, and pain management.
Subjects were 199 adults with hip osteoarthritis recruited from two NHS community musculoskeletal centres in England. Their average age was 63, 57% were women and all reported being in at least moderate pain. They were randomised to one of the three groups, and participants in the injection groups were masked to the type of injection they received.
Patients rated their current intensity of hip pain on a 0-10 scale at 2 weeks and at 2, 4, and 6 months. Over the whole 6 months, those in the BCT plus ultrasound-triamcinolone-lidocaine group reported a greater reduction in pain intensity compared with those receiving either BCT alone or BCT plus ultrasound-lidocaine, by an average score of 1.4 and 0.5, respectively, on the pain scale.
Those in the triamcinolone-lidocaine group were more likely to meet the criterion for low pain (a score of less than 5 on the pain scale) at 2 weeks and at 2 and 4 months than were those in the BCT alone group.
In addition, secondary outcomes including physical function and pain self-efficacy (personal belief in their capacity to improve their health), also showed greater improvements in the BCT-ultrasound-triamcinolone-lidocaine group compared with those receiving BCT alone, and these differences also persisted to 4 months.
The differences in pain scores were greater at 2 weeks and 2 months than at later time points, and no significant differences between the groups in pain or function were reported by 6 months.
However, at 6 months, 58.2% of those in the BCT-ultrasound-triamcinolone-lidocaine group said they were satisfied with the care and treatment received, compared with 34% of those receiving BCT. The dual injection group were also more more likely to say they were not limited in their usual activities because of hip pain (66.7% vs. 44.6%).
Findings Offer an 'Important Choice to Patients'
The researchers said their findings show that steroid-plus-local anaesthetic injections appear to lead to significantly greater pain relief and movement for up to 4 months than current best care in adults with hip osteoarthritis, and injection treatment may provide longer lasting benefits for hip pain.
Although no unexpected adverse events were reported, seven serious events were recorded, one of which (subacute bacterial endocarditis in a participant with a bioprosthetic aortic valve, who died 4 months after receiving BCT plus ultrasound-triamcinolone-lidocaine) was considered possibly related to treatment. The researchers said caution should be applied in patients with signs of, or risk factors for, infection.
They concluded: "In patients with mild to moderate hip osteoarthritis, ultrasound guided corticosteroid and local anaesthetic injection with advice and education led to greater pain reduction and improvement in function over 6 months, compared with advice and education alone.
"This study is the largest randomised controlled trial of the clinical effectiveness of intra-articular corticosteroid injection in hip osteoarthritis," they said. A systematic review of previously published studies reported that the quality of evidence was "relatively poor".
Therefore they concluded: "These findings provide evidence to inform international guidelines and offer important choice to patients, who often believe their treatment options are limited."
Better Short-term Improvement in Pain
Lead author Dr Zoe Paskins, honorary consultant rheumatologist in the School of Medicine at Keele University, told Medscape UK: "I envisage the guidelines, which do not recommend steroid injections for hip osteoarthritis, might change – so that it could be considered as a treatment option, particularly when core treatments are ineffective."
She added: "Unfortunately we only studied the effect of a single injection - we don’t know about the effectiveness or safety of repeated injections, nor do we know if injections would delay the need for [hip] replacement."
Commenting on the study, Dr Wendy Holden, honorary consultant rheumatologist at North Hampshire Hospitals NHS Foundation Trust and medical advisor to UK Charity Arthritis Action said: "Mild to moderate hip osteoarthritis can be painful and disabling and current treatment options are limited to lifestyle advice such as weight loss and exercise. This study suggests that a single injection of local anaesthetic plus corticosteroid given with ultrasound guidance into a painful hip joint may lead to a better short-term improvement in pain and function than advice and education alone.
"This may offer some hope for patients who may not be eligible for joint replacement surgery or who are waiting to see an orthopaedic surgeon to discuss other options.
"The study is limited by not being blinded, so some of the benefits of the injection could be attributed to the placebo effect. In addition, the benefits in terms of a reduction in pain and improvement in function beyond 6 months are unknown."
She added that as 7 of 66 patients who received the active treatment had a serious adverse effect, including one fatal bacterial infection, this "would be considered to be a high complication rate for an intra-articular injection".
Funding for the study was provided by the National Institute for Health Research (NIHR).
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