Correlation between the four types of acromion and the existence of enthesophytes: A study on 423 dried scapulas and review of the literature

Abstract

The purpose of this study was to correlate the four types of acromial shape with the existence of enthesophytes, which together comprise two important parameters for subacromial impingement syndrome and rotator cuff tears. In addition, a review of the literature was carried out. Four hundred twenty-three dried scapulas were studied at the Department of Anatomy in the University of Cologne, Germany. Four types of acromion were found: the three classical ones as described by Bigliani et al. ([1986] Orthop Trans 10:216) and a fourth one, where the middle third of the undersurface of acromion was convex (Gagey et al. [1993] Surg Radiol Anat 15:63-70). The correlation between the four types of acromion and the presence of enthesophytes at its anterior undersurface was also recorded. The distribution of acromial types was as follows: type I, flat, 51 (12.1%); type II, curved, 239 (56.5%); type III, hooked, 122 (28.8%); and type IV, convex, 11 (2.6%). Enthesophytes were found in 1 of type I (2%), in 19 of type II (7.9%), in 46 of type III (37.7%), and in 0 (0%) of type IV acromions. Overall, 66 (15.6%) out of 423 scapulas had enthesophytes. In all cases, they were localized at the site of the coracoacromial ligament insertion on the acromion. Enthesophytes were significantly (P < 0.05) more common in type III acromions and this combination is particularly associated with subacromial impingement syndrome and rotator cuff tears. In type I and in type IV acromions, the incidence of enthesophytes is very small and, according to other studies, with these two acromial types rotator cuff tears are also rare.

Morphometry of Acromion Process of Human Scapulae and Its Clinical Importance Amongst Nepalese Population

“…In type I and type IV acromia the incidence of enthesophytes was very small and rotator cuff tears were rare. 12 In the present study, it is important to note that length and breadth of acromion process of scapulae and acrmiocorocoid distance and acromio-glenoid distance do not present statistically significant differences between right and left scapulae. But we were able to classify acromion process, on the basis of shape, into three types as: Triangular -36.76%, Quadrangular -52.94% and Tubular -10.29%.…”

Osteometry of Acromion Process of Adult Nigerians: Clinical and Forensic Implications

“…It will not be suitable for use from one race to another because of racial variations seen in scapulae. Natsis et al [6] claimed that enthesophytes are significantly more common in the type III acromion and this combination is particularly associated with sub acromial impingement syndrome and rotator cuff tears [6]. The hooked type of acromion, in this study was only 15.38% on the right and 8.18% on the left, given reasons for the uncommon cases of rotator curve tears, enthesophytes and acromial impingement in Nigerian population.…”

“…This classification has not gained much acceptance, mainly owing to the very small incidence of this type of acromion (1.6-13.3%) and the absence of correlation with rotator cuff pathology [5]. Natsis et al [6] claimed that enthesophytes are significantly more common in the type III acromion and this combination is particularly associated with sub acromial impingement syndrome and rotator cuff tears. In type I and type IV acromia the incidence of enthesophytes was very small and rotator cuff tears were rare [6].…”

“…Natsis et al [6] claimed that enthesophytes are significantly more common in the type III acromion and this combination is particularly associated with sub acromial impingement syndrome and rotator cuff tears. In type I and type IV acromia the incidence of enthesophytes was very small and rotator cuff tears were rare [6]. According to Yukio et al [7] the possibility of having a type III acromion is greater as the subject's age increases, allowing for speculation that a hooked form of acromion is a degenerative process [7].…”

Acromial Morphology and Subacromial Architecture in a South African Population

“…Type I acromia presented with a flat inferior surface (17.2%), Type II acromia were characterized by a curved inferior surface (42.9%) and Type III acromia portrayed a hooked inferior surface (39.3%) (Bigliani et al, 1986;Rockwood et al, 2004). Despite the proposal of a fourth acromial type (convex inferior surface) by Gagey et al (1993) and Natsis et al (2007), it has not been related to rotator cuff tendinopathy.…”