At a 10-Year Follow-up, Tendon Repair Is Superior to Physiotherapy in the Treatment of Small and Medium-Sized Rotator Cuff Tears

At a 10-Year Follow-up, Tendon Repair Is Superior to Physiotherapy in the Treatment of Small and Medium-Sized Rotator Cuff Tears

To repair or not to repair, that is the question. This recent paper by Moosmayer et al (2019) appears to provide some much-needed evidence in relation to this question. The authors of this randomised controlled trial conclude: ‘At 10 years, the differences in outcome between primary tendon repair and physiotherapy for small and medium-sized rotator cuff tears had increased, with better results for primary tendon repair.’

When considering whether to go ahead with a surgical repair of the torn rotator cuff, both clinicians and patients are rightfully mindful of the long-term implications of such a decision. Therefore, this 10-year follow-up study is an important contribution to the evidence base.

However, it can be seductive to think that this study supports the need for rotator cuff repair surgery in people with small to medium-sized rotator cuff tears. As always, the devil is in the detail and it is important to read beyond the headline conclusion reported in the abstract.

There are many points of discussion that this paper raises. But, in this short blog, I will focus on statistical significance versus clinical importance and the confidence interval.

The headline figure from Moosmayer et al (2019) is that there is a statistically significant difference between the two treatment groups (surgery versus physiotherapy) in favour of the surgical group with reference to the primary outcome measure, the Constant score. However, statistical significance tells you nothing about clinical importance. For example, you might have a statistically significant difference of 0.4 points on a visual analogue scale but that difference is not recognizable or meaningful to clinicians or patients. However, with regards to this study, the difference between groups is reported as 9.6 points on the Constant Score and a clinically important difference is 10 points. So, this is close and any critique suggesting this is not relevant based on lacking 0.4 points is open to challenge given the uncertainty around determining clinically important differences.

But, and there is a big but here, the point estimate, i.e. 9.6 points on the Constant Score, does not tell the whole story. When we do research, we recruit a sample of patients rather than the whole population and then we attempt to infer the results from this sample to the wider population. Given that the smaller sample cannot be fully representative of the whole population, e.g. everyone with rotator cuff tears, there is always some uncertainty around the treatment effects observed in the sample. Often we express this uncertainty in terms of confidence intervals, i.e. the range of values In which the true population value lies. So, although the estimate of 9.6 points difference on the Constant Score might represent the sample, it doesn’t necessarily reflect the difference in the population and so we need to express a degree of uncertainty.

Despite current convention, it is interesting to note that Moosmayer et al (2019) do not report such confidence intervals in the abstract. But, when reading the full paper, they are easily accessible in Table IV where the confidence interval is reported as 3.6 to 15.7. This means that in the population of patients with rotator cuff tear, surgical repair is superior to physiotherapy and the difference in clinical outcomes, measured on the Constant Score, might range from 3.6 points (clinically meaningless) to 15.7 points (clinically meaningful).

Where from here? Well, there is still a degree of uncertainty. All thing being equal (and that is open to question), surgery offers superior clinical outcomes to physiotherapy at 10-years as measured by the Constant Score. But, that superiority might not be clinically recognisable to the patient and clinician and any decision to undergo surgery needs to consider the risk, burden, e.g. time off work, and patient preference. So, the clinical discussion might be along the following lines; ‘you have a rotator cuff tear, we have different treatment options including surgical repair, physiotherapy, or we could wait and see. Surgical repair seems to offer better clinical outcomes 10 years after surgery, not so after 1, 2 or 5 years, but the extent of this benefit is unclear. If you do opt for surgery then you need to think about the risk and burden of surgery and whether that is acceptable to you given that the clinical importance of long-term benefits are unclear.

Management of rotator cuff tears remains challenging with much uncertainty. My own view is that we need to be more balanced in reporting such research and remain open to the current uncertainty.

Thanks for making it this far – comments welcome and appreciated.

Chris