• AC joint - the acromioclavicular joint; this is the joint that connects the distal end of the clavicle to the acromion, which is part of the scapula, or shoulder blade.

    Acromioclavicular joint - also called the AC joint, this is the joint that connects the distal end of the clavicle to the acromion, which is part of the scapula, or shoulder blade.

    Acromion - the most superior and lateral part of the scapula; the supraspinatus tendon (one of the rotator cuff muscles) passes underneath the acromion before attaching to the humerus. In some cases, a malshaped acromion may lead to shoulder impingement.

    Active exercise - exercise in which the participant uses the muscles of the affected limb to create the limb motion. See also passive exercise.

    Anterior inferior shoulder instability - this is the most common type of shoulder instability; a person with this type of instability may have problems with the humerus subluxing or dislocating out the front of the joint. See also multidirectional instability.

    Arthritis - degeneration of a joint. When a joint becomes arthritic there is a loss of articular cartilage and degenerative changes to the bone.

    Arthroplasty - joint replacement, the creation of an artificial joint, or the surgical restoration of the integrity and functional power of a joint. In shoulder arthroplasty, the arthritic articular surfaces are replaced by metal and polyethylene components.

    Arthroscopic surgery - see arthroscopy.

    Arthroscopy - the use of arthroscopic equipment allows some surgeries to be performed through two or three very small incisions.

    Avascular necrosis - death of bone and cartilage tissue due to impaired or disrupted blood supply (as that caused by traumatic injury or disease) and marked by severe pain in the affected region and by weakened bone that may flatten and collapse. Also called osteonecrosis.

  • Bankart lesion - a defect in the shoulder capsule and labrum caused by a shoulder dislocation. The defect is located at the anteroinferior border of the glenoid. The defect is referred to as a bony Bankart lesion when, in addition to the soft tissue defect, a piece of bone is missing from the anteroinferior glenoid.

    Bankart repair - surgical correction of a Bankart lesion (a torn labral cartilage and shoulder capsule). A Bankart lesion commonly occurs after a shoulder dislocation.

    Biceps repair - tenodesis of the distal biceps tendon to the radius bone, as is necessary for a biceps tendon rupture.

    Biceps tendon - the biceps, also called the biceps brachii, is a large muscle at the front of the upper arm that flexes the forearm. The distal tendon attaches to the radius bone at the radial tuberosity. The biceps is responsible for elbow flexion and forearm supination.

    Biceps tenodesis - the surgical anchoring of a biceps tendon, as to a bone. This term is used most commonly to refer to tenodesis of the long head of the biceps proximally. Tenodesis of the distal biceps tendon to the radius is more commonly referred to as a biceps repair.

    Brachial neuritis - an acute syndrome of unknown cause marked by pain in the shoulder girdle, flaccid weakness of the muscles innervated by the brachial plexus, and mild sensory loss in the affected upper extremity. Brachial neuritis is usually of limited duration with spontaneous recovery. Also called acute brachial radiculitis, brachial plexus neuropathy, shoulder-girdle syndrome, and shoulder-hand syndrome.

    Brachial plexus - a network of nerves formed by cervical and thoracic spinal nerves and supplying the arm and parts of the shoulder.

  • Clavicle - Also called collarbone, it is either of the two slender bones in humans that extend from the manubrium of the sternum to the acromion of the scapula.

    Clavicle fracture - a break, rupture, or crack, of the clavicle bone.

    Coracoid - a bony process projecting from the scapula toward the sternum. Several ligaments attach to the coracoid, as do the tendons of the coricobrachialis muscle and the short head of the biceps.

    Cuff tear arthropathy - a type of arthrosis of the shoulder joint with a unique bony wear pattern. After years of having a massive rotator cuff tear, superior migration of the humeral head is often seen, along with superior wear of the glenoid bone.

  • Deltoid muscle - a muscle with origin from the lateral third of the clavicle, the lateral border of acromion process, and the lower border of spine of scapula, with insertion to the side of the shaft of the humerus, with nerve supply from the axillary nerve from the fifth and sixth cervical nerves through the brachial plexus, and whose action causes the abduction, flexion, extension, and rotation of the arm.

    Dislocation - displacement of a body part, especially the temporary displacement of a bone from its normal position within a joint.

  • External rotators - a term that is commonly used to refer to the infraspinatus and teres minor muscles, which affect external rotation of the shoulder.

  • Fracture - a break, rupture, or crack, of a bone .

  • Glenohumeral arthritis - shoulder arthritis. Inflammation of the shoulder, usually accompanied by pain, swelling, and stiffness, and resulting from infection, trauma, degenerative changes, metabolic disturbances, or other causes. It occurs in various forms, such as bacterial arthritis, osteoarthritis, or rheumatoid arthritis.

    Glenohumeral joint - the shoulder joint.

    Glenoid - the articular depression of the scapula entering into the formation of the shoulder joint.

  • Hemiarthroplasty - arthroplasty in which one joint surface is replaced with artificial material, usually metal. In shoulder hemiarthroplasty, the proximal humerus is usually replaced, rather than the glenoid.

    Heterotopic ossification - the pathologic formation of bony tissue in a location where bone does not normally form, e.g. within muscle.

    Hoop stresses - the type of force that holds a press-fit prosthesis into a bone during joint replacement.

    Humeral head - the smooth, round articular surface of the proximal humerus bone.

    Humerus - the bone of the arm, articulating with the scapula above and the radius and ulna below.

  • Impingement - a term often used, when referring to the shoulder, to describe the concept of pathologic pressure on the rotator cuff from part of the shoulder blade (scapula) as the arm is lifted.

    Infraspinatus muscle - an intrinsic (scapulohumeral) muscle of the shoulder joint. The tendon of this muscle contributes to the formation of the rotator cuff; origin, infraspinous fossa of scapula; insertion, middle facet of greater tubercle of humerus; action, extends arm and rotates it laterally; its tonic contraction helps to hold the head of the humerus in the shallow glenoid fossa; nerve supply, suprascapular (from fifth to sixth cervical spinal nerves).

    Internal rotator muscle - a term that is commonly used to refer to the subscapularis muscle, which affects internal rotation of the shoulder.

    Interscalene block - a procedure that is used to provide pain relief for shoulder surgery. An anesthetic (e.g. bupivcaine) is injected near the nerves as they exit from the neck region. This often leads to better pain control with less need for narcotic pain medications.

  • Labrum - a rim or cup of cartilage that contributes to shoulder stability by deepening and increasing the glenoid surface area, and by providing attachments for the shoulder capsule and various ligaments and tendons.

  • Mini open repair - a surgical technique that is used to repair the rotator cuff through a single, small incision, usually about 3 cm long.

    Multidirectional instability (MDI) - shoulder instability in patients who have generalized looseness of the supporting ligaments that surround the shoulder’s glenohumeral joint. The laxity can be a congenital condition (present from birth) or a condition that has developed over time, often from repetitive activities that stretch the shoulder capsule such as overhead sports (volleyball, gymnastics, swimming, or throwing).

  • Osteoarthritis - arthritis that occurs with aging or as a sequela of trauma characterized by degenerative and sometimes hypertrophic changes in the bone and cartilage of a joint and a progressive wearing down of apposing joint surfaces with consequent distortion of joint position. Also called degenerative arthritis, degenerative joint disease, hypertrophic arthritis, post-traumatic arthritis.

    Osteonecrosis - necrosis of bone tissue due to impaired or disrupted blood supply (as that caused by traumatic injury or disease) and marked by severe pain in the affected region and by weakened bone that may flatten and collapse. Also called avascular necrosis.

  • Passive exercise - exercise that emphasizes maintaining range of motion rather than strengthening. During a passive shoulder exercise, for example, the surgical shoulder and arm remain loose while the unaffected arm provides the power to take the shoulder through a range of motion. See also active exercise.

    Posterior shoulder instability - a condition in which the head of the humerus tends to sublux or dislocate posterior to the shoulder joint (out toward the back). Posterior instability is much less common than anterior instability. Patients with this condition often don’t present with a typical history of true dislocations, but rather symptoms of posterior joint pain and/or clicking. Athletes, such as weight lifters may be at higher risk for developing this disorder. Posterior dislocation of the shoulder has also been associated with a history of seizures or an electrical shock.

    Prosthesis (pl. prostheses) - an artificial device used to replace a missing body part. A shoulder prosthesis is usually made of metal and plastic.

  • Reverse shoulder prosthesis - an artificial shoulder joint made from metal and plastic that is used to replace a natural shoulder joint that is worn out, painful, and/or no longer functions properly. With a reverse shoulder prosthesis, the ball (humeral head) and socket (glenoid cup) are switched or “reversed.” There may be advantages to using a reverse shoulder prosthesis in patients with an irreparable, massive rotator cuff tear or significant glenoid bone loss. Compare to standard shoulder prosthesis.

    Revision surgery - surgery that is performed after a previous, initial surgery; a revision surgery may be performed for many reasons, e.g. to correct alignment, replace worn out components, etc.

    Rheumatoid arthritis - a usually chronic disease that is considered an autoimmune disease and is characterized especially by pain, stiffness, inflammation, swelling, and sometimes destruction of joints.

    Rotator cuff - a supporting and strengthening structure of the shoulder joint that is made up of part of its capsule blended with tendons of the subscapularis, infraspinatus, supraspinatus, and teres minor muscles as they pass to the capsule or across it to insert on the humerus. Also called the musculotendinous cuff.

  • Scapula - Either of two large, flat, triangular bones forming the back part of the shoulder. Also called shoulder blade.

    Scapular winging - a rare condition sometimes caused by nerve injury or another disorder affecting the shoulder; “winging” refers to abnormal protrusion of a part of the scapula.

    Septic arthritis - acute inflammation of synovial membranes, with purulent effusion into a joint, due to bacterial infection; the usual route of infection is hemic to the synovial tissue, causing destruction of the articular cartilage, and may become chronic, with sinus formation, osteomyelitis, deformity, and disability. Also called suppurative arthritis.

    SLAP tear - a tear of the superior labrum of the shoulder. SLAP is an acronym for Superior Labrum Anterior Posterior. If the arm is forcefully bent inward at the shoulder, the humerus acts as a lever and tears the long head of the biceps tendon and labrum cartilage from the glenoid cavity in a front-to-back (anterior-posterior) direction.

    Standard shoulder prosthesis - an artificial shoulder joint made from metal and plastic that is used to replace a natural shoulder joint that is worn out, painful, and/or no longer functions properly. With a standard shoulder prosthesis, the ball (humeral head) and socket (glenoid cup) are fabricated in a manner that imitates the shoulder’s normal anatomy. Compare to reverse shoulder prosthesis.

    Subscapularis muscle - one of four rotator cuff muscles. The subscapularis is located on the undersurface of the scapula and connects to an area on the proximal humerus bone called the lesser tubercle. It is responsible for internal rotation of the arm at the shoulder.

    Supraspinatus muscle - one of four rotator cuff muscles. The supraspinatus sits on the superior, posterior scapula in an area known as the supraspinatus fossa, and it connects to the proximal humerus bone at the greater tubercle. It contributes to stabilization of glenohumeral joint. The supraspinatus is the most often injured rotator cuff muscle.

    Suture anchor - a small screw made of metal or synthetic material that is buried into the bone during some shoulder surgeries. Sutures or stitches run through an eyelet in the screw, and these are used to repair soft tissues and hold them to the bone.

    Synovial osteochondromatosis (SOC) - a benign condition characterized by synovial membrane proliferation and metaplasia. The entity also is termed synovial chondromatosis. The synovial lining of a joint, bursa, or tendon sheath undergoes nodular proliferation, and fragments may break off from the synovial surface into the joint. In this location and nourished by synovial fluid, the fragments may grow, calcify, or ossify. The intra-articular fragment may vary in size from a few millimeters to a few centimeters.

  • Tenodesis - the surgical anchoring of a tendon, as to a bone.

    Teres minor muscle - one of four rotator cuff muscles, it originates from the lateral border of the scapula and inserts into the proximal humerus at the greater tubercle. It contributes to the shoulder’s external rotation strength.

    Total elbow arthroplasty - replacement of the shoulder joint with an artificial device, usually made from metal and high-density plastic.

    Total joint arthroplasty - arthroplasty in which both joint surfaces are replaced with artificial materials, usually metal and high-density plastic.

    Total shoulder arthroplasty - replacement of the shoulder joint with an artificial device, usually made from metal and high-density plastic.