Open acromioplasty does not prevent the progression of an impingement syndrome to a tear

Open acromioplasty does not prevent the progression of an impingement syndrome to a tear / Author’s reply

Bernstein, J

Sir

I read with interest the article by Hyvonen et al1 in the September 1998 issue entitled `Open acromioplasty does not prevent the progression of an impingement syndrome to a tear’. Their conclusion is given in the title. I believe that, given their data, it is reasonable to decide exactly the opposite, namely, that acromioplasty does prevent tears.

Their study showed that about 20% of cases of impingement without associated tears of the cuff went on to sustain a tear. In the absence of a control group for comparison, meaningful inferences cannot be made. If the baseline rate of progression was 100%, then acromioplasty gives a reduction of 80% in the risk, and can reasonably be described as ‘preventing’ tears. If, on the other hand, the baseline risk was closer to the rate of 20% observed after surgery, then the authors’ conclusions are justified. As described, we simply do not know.

The theories regarding the pathogenesis of tears of the rotator cuff are vigorously contested. Researchers ask whether the acromion causes or abets the process. A study which shows that acromioplasty does not prevent tears sheds light on that debate. Unfortunately, this article does not.

J. BERNSTEIN, MD

University of Pennsylvania

Philadelphia, USA.

1. Hyvonen P, Lohi S, Jalovaara P. Open acromioplasty does not prevent the progression of an impingement syndrome to a tear. J Bone Joint Surg [Br] 1998;80-B:813-6.

Author’s reply:

Sir

We thank Dr Bernstein for his comments regarding our interpretation of our data. On the basis of clinical experience we know that the baseline of the progression of the impingement syndrome from tendinitis to tear is not 100%, since conservative treatment is successful in many cases in the initial phase and there is no evidence to suggest that all of these would later develop into a tear. The assumption that an impingement syndrome would only follow mechanical compression exerted by the acromion on the cuff would mean that relief of compression would interrupt the inflammatory process in the cuff and no tears would appear after acromioplasty. If we had not found any tears in our long-term follow-up study it might have been concluded that the mechanical theory of the pathogenesis of the impingement syndrome is true. We observed a tear of the cuff in 20% of our cases which suggests that primary degeneration of the cuff is in some way involved in the pathogenesis of the impingement syndrome. In this sense, we consider our title to be justified. We assume that many questions remain open: What is the role of age-related degeneration in the impingement syndrome? Is this deterioration primary or is it caused by the acromion? etc. Before our study there was no information available on the long-term condition of the cuff after acromioplasty.

P. JALOVAARA, MD, PhD

University of Oulu

Oulu, Finland.

Copyright British Editorial Society of Bone & Joint Surgery Jul 1999

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