PERSPECTIVES

Drs. de SA and Bhandari discussed a paper by Gazendam and colleagues that has been accepted for publication in the British Journal of Sports Medicine (Impact factor: 12.022 bjsm). Our discussion uncovered 3 core themes. These themes and their supporting insights are highlighted below.

1. Rethinking Hip Injection: Corticosteroids, HA, and PRP no better than saline

In this paper (OE Original), the authors conducted a network meta-analysis (NMA) that included 11 randomized controlled trials (RCTs) with 1353 patients evaluating the efficacy of intra-articular (IA) hip injections for treating osteoarthritis (OA). Below is a summary of this NMA.

Patients: Hip OA ranged from Kellgren-Lawrence grades 1-4 (the majority being in grades 2-3)
Interventions: Corticosteroids, hyaluronic acid (HA), platelet-rich plasma (PRP), HA+PRP
Controls: Saline, no injection
Outcomes: Pain, function at 2-4 and 6 months

Main findings:
-    No intervention significantly outperformed the placebo IA injection.
-    Except for a comparison between HA+PRP versus no injection, the rest of the IA injections did not lead to a pain reduction that exceeded the minimal clinically important difference (MCID).

2. Digging deeper: Is there something we’re not capturing?

Dr. de SA regards that this is a methodologically sound study by providing the pooled results from RCTs. In Dr. de SA’s opinion, we also have to consider the following aspects.

a)    Compared to knee OA, the literature of IA injections for hip OA is relatively scarce. The included 11 RCTs were relatively small with a median trial sample size of 80 patients.

b)    Your own patients may be different from the patients included in the RCTs. Clinicians need to consider the applicability of the results.

I think it's important that this study and the decisions that you raise [...] the need for appropriate patient selection [...] by and large, injections joint pain may not be applicable to every patient [...] we just don't understand the relative contribution of the many factors that go into one's response to them, if at all.

Dr. de SA

c)    Significant heterogeneity across treatments under the same category existed including doses, injection frequencies and formulation of injectables.

The hard part with particularly injection therapy, at least taking it from the literature, is that there's significant heterogeneity across many different aspects of it, in terms of doses, frequency of injections. PRP literature in general is quite over the place with regards to formulations, and we don't really know exactly what we're injecting.

Dr. de SA

d)    Not all important outcomes, especially in terms of longevity, were available for this network meta-analysis.

We're looking at one-year, two-year outcomes. Is it just pain or function? There's a lot still to capture.

Dr. de SA

3. Future research: High-quality large single trial

Dr. de SA believes that this study is a springboard that is bringing clinicians to start discussing the efficacy of IA injections for treatment of hip OA, especially whether any efficacies can be influenced by a placebo effect. An ideal future trial should include a large sample size, take into account more important outcomes determined by the consensus of expert clinicians, and follow-up patients for a longer term.

Rather than doing multiple small trials and combining 11 randomized trials to get 1300 patients, we should try to get 1300 patients in a single trial. Maybe that will be the ultimate driver of change in the longer term.

Dr. Bhandari

SENSE-MAKING

Drs. de SA and Bhandari discussed results from an NMA which showed that IA injections of corticosteroids, HA, and PRP are no better than saline for treatment of hip OA. It is less likely to shift practice of clinicians. Rather, this study will serve as a springboard to go forward.