Open versus arthroscopic acromioplasty
======================================

* Shawn W. O’Driscoll

The article comparing open and arthroscopic acromioplasties by Kinnard and associates in the February 1996 issue of the Journal (pages 21 to 23) is of great interest. The authors are to be congratulated for attempting to compare the relative benefits of the two procedures. However, there are a couple of points that merit clarification.

First, they did not report on the power of their study. This is important since they conclude that there was no significant difference in time off work between the two procedures. With a total sample of 20, they would only have an 80% power of determining a difference in the means of one standard deviation, which is considered a “large-effect” difference. Also, they did not report the confidence interval for the difference in means. Considering that the data may well be skewed rather than normally distributed, these data would be important.

The authors state that “in reality, it [arthroscopic acromioplasty] is much more difficult that open acromioplasty . . . . ” Many would take strong exception to this statement. Although surgeons recognize that arthroscopic acromioplasty is an exceedingly difficult operation for some to learn, the majority of surgeons experienced and skilled in this technique find that the procedure is easier and faster to perform than open acromioplasty.

Finally, the difference in morbidity between these two procedures is striking. Having had an arthroscopic acromioplasty myself, I can attest to the fact that I was able to take part in a scientific meeting later on the day of the procedure and take an international flight and drive for 1 hours by myself the next day. I would not anticipate being able to do this after an open acromioplasty.

I do not believe that every orthopedic surgeon who has mastered the open technique should feel obliged to learn the arthroscopic technique. Nevertheless, the advantages of the arthroscopic technique should not be underestimated and should be evaluated in a rigorous scientific fashion.