Abstract
Rotator cuff pathologies are related with higher incidence of morbidity in the modern society in young patients. Although it is well known that rotator cuff is sandwiched between the acromion and humeral head during various movements of the shoulder joint, only few studies have investigated this looking at the humeral head as a culprit for the rotator cuff pathology.
We carried out the cadaveric study of 15 shoulder joints to find out the influence of the humeral head anatomy on the rotator cuff pathology. We dissected 15 shoulder joints and looked at the rotator cuff tears. All the specimens were examined and photographed digitally from the superior aspect of shoulder joint. All these images were entered into a computer and using special software, we carried out 3D reconstruction of these images. With this software, the outermost point of intersection of humerus head with acromion decided. We calculated the area of the humeral head in an outside the acromion and correlated with the rotator cuff tear.
We found that the area of the humeral head outside the acromion is variable, ranging from 18% to 50% of diameter of humeral head (mean 34%, median 33%, mode 20%, 33%, 45%). When the area of humerus head outside the acromion is less than 32% of the diameter of head (i.e. humerus head was more under the acromion and less outside the outer most point of acromion), those specimens had either incomplete or complete rotator cuff tear.
We conclude that when the area of humeral head, covered under the acromion is more than 68% of the diameter of the head, they have more chances of developing rotator cuff pathology as compare to other individual.
The abstracts were prepared by Mr Roger Emery. Correspondence should be addressed to him at the British Orthopaedic Association, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN
