TO THE EDITOR:
In "Current Concepts Review. Subacromial Impingement Syndrome" (79-A: 1854—1868, Dec. 1997), Bigliani and Levine cited a study by us2. The authors indicated that we "used anatomical specimens to investigate the contact areas of the subacromial joint; however, the use of such specimens did not allow for direct clinical correlation." This statement is contrary to our findings and observations.
In 1981 and 1982, we studied sixty cadaveric shoulders and performed studies of the contact area between the rotator cuff and the inferior acromial surface. Multiplane radiographs were made of twelve acromions. Full-thickness tears of the rotator cuff were noted in eight of the sixty shoulders. In all eight shoulders, a corresponding area of osteophytes and osseous excrescences was observed on the anterior-inferior surface of the ipsilateral acromial process. In each instance, the pathological changes in the cuff corresponded to the stained contact area.
We also noted that some tears were associated with a curved hook-like structure projecting from the anterior-inferior surface of the acromion. This structure resulted in reduced space between the acromial process and the tendons of the cuff. Lateral radiographs of several acromial processes showed flat acromions with 15 degrees of inferior inclination, curved acromions with 20 degrees of inferior inclination or more, and acromions with a hook-like appearance along the anterior-inferior edge.
It appears that the terms flat, hooked, and curved could be inferred from Figure 4, on page 136 of our article2 (Fig. 1). It appears to us that Bigliani and Levine have essentially put labels on our radiographs.
In 1986, Bigliani et al. reported on the morphology of the acromion and its relationship to tears of the rotator cuff1. Those authors claimed credit for describing type-I (flat), type-II (curved), and type-III (hooked) acromial processes, which were well illustrated and discussed by us in 19842. We also presented our work at the Second International Shoulder Conference in Toronto in 1983. Dr. Bigliani was listed as a participant at that conference.
Richard J. Nasca, M.D.: 7241 Hanover Parkway, Suite A, Greenbelt, Maryland 20770
E. George Salter, Ph.D.: University of Alabama, Birmingham, 1670 University Boulevard, Birmingham, Alabama 32594-0019
Craig E. Weil, M.D.: 1211 Johnson Ferry Road, Marietta, Georgia 30068
Dr. Bigliani and Dr. Levine reply:
We did not mean to slight the clinical relevance of the contributions of Nasca et al.2. The point of our statement concerning direct clinical correlation was that the study by Nasca et al. was not a clinical study but rather a cadaveric study. Therefore, we apologize if there was any misunderstanding concerning the term direct clinical correlation. Our intent was to note that this study was not performed on patients who had impingement syndrome but rather was a basic-science cadaveric study.
In reference to the other issue, one of us (L. U. B.) has, in the past, spoken with Dr. Nasca concerning acromial morphology and was in attendance at the meeting in 1983. Our institution has its own history of interest and involvement with impingement lesions and acromial morphology. For years, Neer and colleagues discussed the formation of anterior acromial spurs and the increased slope of the anterior aspect of the acromion3-5. We have always referenced the work of Nasca et al.2 and continue to hold it in high regard. In our research, we attempted to classify acromions into three basic shapes after studying a rather large series of acromions and finding that they fell into these broad categories. This classification into three types was not included in the article by Nasca et al. At our institution, we continue to do a substantial amount of clinical and basic-science work concerning subacromial shape and contact, and we believe that the contributions of Nasca et al. in this area are quite relevant.
Louis U. Bigliani, M.D.; William N. Levine, M.D.: New York Orthopaedic Hospital Associates, Incorporated, Columbia-Presbyterian Medical Center, 161 Fort Washington Avenue, New York, N.Y. 10032