Hip osteoarthritis (OA) is a leading cause of disability worldwide. Treatment guidelines typically advise combining non-pharmacologic and pharmacologic therapies, with the latter often meaning intra-articular injection of a steroid to reduce pain and swelling.
Some clinical trials have shown that these injections are beneficial for up to 8 weeks, but overall, the evidence is conflicting.
A new study from the UK published by The BMJ adds to the literature supporting steroid injections, and also suggests that pain relief may last longer than 8 weeks: The researchers report that steroid injections appeared to lead to significantly greater pain relief and movement for up to 4 months than current best care in adults with hip OA.
For the study, the researchers compared the clinical effectiveness of advice and education – considered to be the best current treatment, or BCT – with BCT plus a single ultrasound-guided intra-articular injection of a corticosteroid and a local anesthetic in individuals with hip OA.
The study cohort included 199 adults (average age 63 years; 57% women) with hip OA who reported at least moderate pain at 2 National Health Service community musculoskeletal centers in England. These patients were randomly assigned to 1 of 3 groups:
- BCT only (n=67)
- BCT plus ultrasound-guided injection of the steroid triamcinolone and the anesthetic lidocaine (n=66)
- BCT plus ultrasound-guided injection of lidocaine only (n=66)
Baseline characteristics were similar among the groups, and participants in the ultrasound-guided groups were masked to the injection they received.
The primary outcome measure was intensity of hip pain on a 0 to 10 numerical rating scale at 2 weeks and 2, 4, and 6 months. Secondary outcomes included physical function and pain self-efficacy (an individual’s belief in their capacity to improve their health).
Over the 6-month study period, participants in the BCT plus steroid and anesthetic group reported a greater reduction in pain intensity, by an average pain scale score of 1.4 and 0.5, than those receiving BCT alone or BCT plus anesthetic, respectively.
Generally, greater differences were seen at earlier time points (2 weeks and 2 months) than at later time points (4 and 6 months), and no significant differences in pain or function were reported at the 6-month time point.
Participants in the BCT plus steroid and anesthetic group were more likely to meet the criterion for low pain (a score of less than 5 on the pain scale) at 2 weeks, 2 months, and 4 months than those in the BCT group.
Greater improvements in physical function and pain self-efficacy also persisted to 4 months in the BCT plus steroid and anesthetic group compared with those receiving BCT alone.
At 6 months, participants in the BCT plus steroid and anesthetic group were more likely to be satisfied with their care and treatment than those receiving BCT alone (58.2% vs 34%) and were more likely to say they were not limited in their usual activities because of hip pain (66.7% vs 44.6%).
Seven serious adverse events were recorded, 1 of which – a bacterial infection – was considered possibly related to the trial treatment. The researchers said that caution should be applied in patients with risk factors for, or signs of, infection.
Strengths and Limitations
The researchers acknowledged some trial limitations, including a lack of blinding between the BCT and the BCT plus ultrasound-guided treatment groups and relying on self-reporting by patients, which may have affected accuracy.
However, strengths include the large sample size, the inclusion of 2 comparison arms, the length of follow-up, and the high response rates. Results were also similar after further analyses, suggesting that they were robust.
As such, the researchers concluded that, “In patients with mild to moderate hip osteoarthritis, ultrasound-guided corticosteroid and local anesthetic injection with advice and education led to greater pain reduction and improvement in function over 6 months, compared with advice and education alone.
“These findings provide evidence to inform international guidelines and offer important choice to patients, who often believe their treatment options are limited.”
Paskins Z, Bromley K, Lewis M, et al. Clinical effectiveness of one ultrasound guided intra-articular corticosteroid and local anaesthetic injection in addition to advice and education for hip osteoarthritis (HIT trial): single blind, parallel group, three arm, randomised controlled trial. BMJ. 2022 Apr 6;377:e068446. doi: 10.1136/bmj-2021-068446.