The shoulder is a complex ball-and-socket joint known as the glenohumeral joint. The socket, known as the glenoid, is part of the shoulder blade (scapula) and is a shallow cavity for the ball of the joint to attach. The glenoid is covered in a layer of cartilage, which acts to cushion and lubricate the joint, allowing for smooth motion. A layer of specialized cartilage known as the glenoid labrum forms a ring around the socket that adds depth to the joint, creates a seal that maintains joint fluid within the shoulder and increases overall stability to the shoulder socket. The capsule around the labrum has regions of thickening that add stability to the shoulder and these regions are known as glenohumeral ligaments. Collectively, this structure of thickened ligaments and the labrum that encircles the joint is called the capsulolabral complex. The labrum is frequently torn in pre-arthritic conditions when the ball of the joint comes out of the socket. The ball of the ball-and-socket joint is the top part of the upper arm bone (humerus) known as the humeral head. The ball is also covered in a layer of cartilage that contacts the cartilage layer of the socket, again allowing for smooth movement. Labrum tears lead to weakness and shoulder instability that can result in recurrent dislocations. A torn labrum causes pain that is intensified during high-demand activates (throwing, pressing, lifting) and normal daily activities (reaching up, putting on a shirt, picking up objects, etc.)
Several other muscles, bones and ligaments surround the shoulder joint to add stability and allow movement of the shoulder. The rotator cuff is made up of 4 muscles that create a sleeve over the shoulder and help lift and rotate the joint. A rotator cuff tear can be painful and cause a lot of difficulty with raising the arm with the affected shoulder. Shoulder impingement can result when the tendons of the rotator cuff become inflamed as well as other tissue in the shoulder. The acromioclavicular (AC) joint is comprised of several ligaments that connect the shoulder blade (scapula) and clavicle (collarbone) at the front of the shoulder. Tears in the ligaments that make up the AC joint lead to a separated shoulder. Also, the clavicle is one of the most commonly fractured bones in the body and clavicle fractures cause sharp pain in the front of the shoulder. Another important muscle that attaches to the shoulder is the bicep (upper arm muscle). Bicep tendon injuries cause pain and limited mobility in the arm and can occur in conjunction with other injuries in the shoulder like labrum tears.
Minimally invasive shoulder arthroscopy can help identify and repair shoulder injuries that involve the soft tissues (muscle, tendon, ligament) surrounding the shoulder joint. Specialized procedures for shoulder stabilization are often used to repair a torn labrum and restore strength and mobility to the shoulder joint. Damage to the layer of cartilage that covers the surface of the humeral head and glenoid can result in osteoarthritis. Osteoarthritis (arthritis) is a loss of the cartilage surface in a joint, resulting in painful bone-to-bone contact. When it becomes advanced and painful enough, the only available option is a total shoulder replacement, which removes the arthritic parts of the joint and replaces them with metal, ceramic and/or plastic.There are several other shoulder injuries that can cause pain and functional limitations of the shoulder. These include SLAP tears, frozen shoulder, and pectoralis ruptures. These injuries and their respective treatments are listed below. If you have any of the following conditions or undiagnosed shoulder or upper arm pain, please contact us for an appointment.