The shoulder is the coming-together of three bone structures: the scapula (shoulder blade); the humerus (upper arm bone); and the clavicle (collarbone). The humerus articulates, or loosely connects to allow motion, with (i) the scapula (above the humerus); and (ii) radius and ulna (below the humerus).
First, a lesion is defined, according to Stedman’s Medical Dictionary, as a wound, injury or any pathological change in tissue. Pathological refers to the essential nature, development and causes of any abnormal condition (i.e. the physical and functional changes induced by an illness).
A Bankart Lesion refers to an injury to the part of the shoulder known as the labrum. Labrum is a cuff of cartilage that forms a cup at the humerus. to The labrum provides stability for, and movement of, the shoulder joint within it.
When the labrum of the shoulder joint is torn (this tear is a type of lesion), the shoulder joint becomes less stable. The Bankart Lesion is a specific type of labrum tear that usually occurs when the shoulder pops out of the joint (i.e. when someone dislocates their shoulder). In the process of the shoulder dislocating, the labrum tears.
If you hold your arm out to your side and bend at the elbow (creating a “J” or “L” shape with your arm) and push back on your arm (gently please), you can feel the very beginning of a motion, that if greatly exaggerated, would lead to a Bankart Lesion. Bankart Lesions occur often as a result of someone falling on an outstretched hand in addition excessively, strenuously and repeatedly throwing a ball can cause the condition as well.
Hill-Sachs lesion or fracture is a cortical depression (depression here refers to an inward or downward displacement) in the posterior superior head of the humerus bone. Cortical refers to a cortex, which is the outer portion of an organ.This is usually the result of an injury to the humeral head by the rim of the glenoid fossa after anterior glenohumeral dislocation…in other words, when the humeral head strikes the inferior margin/rim of the glenoid.
Hill Sachs lesion may destabilize the glenohumeral joint and may predispose the sufferer to future dislocation.The presence of a Hill-Sach’s lesion is a specific sign of dislocation (even if the joint has since been reset).The dislocation may also cause a Bankart Fracture at the impact site on the glenoid.