OA of the hip: The HIT Trial

Osteoarthritis of the hip: common, painful, hugely limiting to function and quality of life and now post pandemic we and our patients face huge delays and barriers to surgical referral. We advise patients on weight loss, we refer if we can for physio and structured exercise programmes but the patient with pain and limitations on their quality of life and function keep coming back to us for help. What next? 

To be fair, the treatment cupboard for OA has always looked pretty bare but it is barer still now that paracetamol and weak opioids have been removed as recommendations in the new draft NICE guidelines for OA NICE OA draft guideline, 2022. So, apart from weight loss and exercise, what else can we offer? 

A recent trial called the HIT trial has published 2022;377;e068446. It deserves a prize for its short and punchy acronym alone (the Hip Injection Trial), but the results are similarly impressive. Patients with mild to moderate OA hip, but with significant pain and functional limitation, were randomised to best current treatment (BCT) comprising education and information or BCT plus ultrasound guided injection of local anaesthetic (lidocaine) plus or minus steroid (triamcinolone).  The improvements in the injection groups were rapid and sustained. For the combined injection patients had a 50% reduction in pain scores at 2 weeks, with a mean improvement of 25% over 6 months. The NNT at 2 months were just 2 for improved sleep, 3 for feeling better and 3 for no limits to functional activity. Those are impressive results. At 6 months pain relief was not sustained but functional improvements persisted.

Interestingly, the anti-inflammatory effect of the steroid was most beneficial when the scan revealed active synovitis or effusion.  It suggests the anti-inflammatory benefits will be greater earlier in the disease process when there is still some joint lining to become actively inflamed. Once we get to ‘bone on bone’ it is an intervention which is less likely to help.  In an accompanying editorial BMJ2022;377:o1028 the authors discuss how this confirms that we should discard the old view of OA as being due to ‘wear and tear’, and conceptualise the pathology instead as a model of ‘tear, flare and repair’. The term ‘wear and tear’ arthritis should be abandoned;  it is negatively framed, reinforces expectations of inexorable decline and discourages exercise and use which we know is beneficial.

So, we have a non-surgical intervention for OA that gives rapid and effective short-term relief whilst patients are waiting for surgery. Let us hope our commissioners make it available to us and our patients just as rapidly!