تصنيف كسور العضد القريبة - تصنيف نير proximal humeral fracture classification - Neer classification

classification of proximal humerus fractures. The proximal humerus comprises four “parts”. the anatomical neck, at the base of the widened articular surface of the humeral head. The greater and lesser tuberosities, they are the sites of attachment for the tendons of the rotator cuff muscles. The surgical neck which is located at the constriction distal to the humeral head and tuberosities. This is where the articular capsule attaches . Proximal humerus fracture includes all fractures to the anatomical neck, greater tuberosity. lesser tuberosity. or surgical neck. either isolated or in combination. Radiographs are used to classify the fracture in terms of the displacement of the parts affected. The most widely employed, however, is the Neer classification. This classification system is based upon the anatomical relationship of the four segments . the greater tuberosity. the lesser tuberosity. the humeral head including articular surface. and the humeral shaft. Thus, fractures are defined by the number of parts involved (one-part through four-part). and additional categories for articular fracture and dislocation. In order to qualify as a part, the fragment must have greater than 1 cm of displacement from a normal anatomic position or 45 degrees of angulation. The greater tuberosity is an exception to this rule, requiring only 0.5 cm of displacement to be considered a part. A fracture without displaced fragments is a “one-part”, regardless of the number of fracture lines. “Two-part fractures” have one displaced fragment, which is the greater tuberosity, lesser tuberosity, or articular segment at the level of the anatomical neck or surgical neck. Three-part fractures are defined by two displaced fragments, but the humeral head remains in contact with the glenoid. Four-part fractures are defined by three or more displaced fragments. The articular surface remains in contact with the glenoid. This is a serious injury and a high risk of avascular necrosis.