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Shoulder

  • Anatomy
  • Conditions
  • Procedures

The shoulder is the most flexible joint in the body that enables a wide range of movements including forward flexion, abduction, adduction, external rotation, internal rotation, and 360-degree circumduction. Thus, the shoulder joint is considered the most insecure joint of the body, but the support of ligaments, muscles, and tendons function to provide the required stability.

Bones of the Shoulder

The shoulder joint is a ball and socket joint made up of three bones, namely the humerus, scapula, and clavicle.

Humerus

The end of the humerus or upper arm bone forms the ball of the shoulder joint. An irregular shallow cavity in the scapula called the glenoid cavity forms the socket for the head of the humerus to fit in. The two bones together form the glenohumeral joint, which is the main joint of the shoulder.

Scapula and Clavicle

The scapula is a flat triangular-shaped bone that forms the shoulder blade. It serves as the site of attachment for most of the muscles that provide movement and stability to the joint. The scapula has four bony processes - acromion, spine, coracoid and glenoid cavity. The acromion and coracoid process serve as places for attachment of the ligaments and tendons.

The clavicle bone or collarbone is an S-shaped bone that connects the scapula to the sternum or breastbone. It forms two joints: the acromioclavicular joint, where it articulates with the acromion process of the scapula and the sternoclavicular joint where it articulates with the sternum or breast bone. The clavicle also forms a protective covering for important nerves and blood vessels that pass under it from the spine to the arms.

Soft Tissues of the Shoulder

The ends of all articulating bones are covered by smooth tissue called articular cartilage, which allows the bones to slide over each other without friction, enabling smooth movement. Articular cartilage reduces pressure and acts as a shock absorber during movement of the shoulder bones. Extra stability to the glenohumeral joint is provided by the glenoid labrum, a ring of fibrous cartilage that surrounds the glenoid cavity. The glenoid labrum increases the depth and surface area of the glenoid cavity to provide a more secure fit for the half-spherical head of the humerus.

Ligaments of the Shoulder

Ligaments are thick strands of fibers that connect one bone to another. The ligaments of the shoulder joint include:

Coracoclavicular ligaments: These ligaments connect the collarbone to the shoulder blade at the coracoid process.
Acromioclavicular ligament: This connects the collarbone to the shoulder blade at the acromion process.
Coracoacromial ligament: It connects the acromion process to the coracoid process.
Glenohumeral ligaments: A group of 3 ligaments that form a capsule around the shoulder joint and connect the head of the arm bone to the glenoid cavity of the shoulder blade. The capsule forms a watertight sac around the joint. Glenohumeral ligaments play a very important role in providing stability to the otherwise unstable shoulder joint by preventing dislocation.

Muscles of the Shoulder

The rotator cuff is the main group of muscles in the shoulder joint and is comprised of 4 muscles. The rotator cuff forms a sleeve around the humeral head and glenoid cavity, providing additional stability to the shoulder joint while enabling a wide range of mobility. The deltoid muscle forms the outer layer of the rotator cuff and is the largest and strongest muscle of the shoulder joint.

Tendons of the Shoulder

Tendons are strong tissues that join muscle to bone allowing the muscle to control the movement of the bone or joint. Two important groups of tendons in the shoulder joint are the biceps tendons and rotator cuff tendons.

Bicep tendons are the two tendons that join the bicep muscle of the upper arm to the shoulder. They are referred to as the long head and short head of the bicep.

Rotator cuff tendons are a group of four tendons that join the head of the humerus to the deeper muscles of the rotator cuff. These tendons provide more stability and mobility to the shoulder joint.

Nerves of the Shoulder

Nerves carry messages from the brain to muscles to direct movement (motor nerves) and send information about different sensations such as touch, temperature, and pain from the muscles back to the brain (sensory nerves). The nerves of the arm pass through the shoulder joint from the neck. These nerves form a bundle at the region of the shoulder called the brachial plexus. The main nerves of the brachial plexus are the musculocutaneous, axillary, radial, ulnar and median nerves.

Blood vessels of the Shoulder

Blood vessels travel along with the nerves to supply blood to the arms. Oxygenated blood is supplied to the shoulder region by the subclavian artery that runs below the collarbone. As it enters the region of the armpit, it is called the axillary artery and further down the arm, it is called the brachial artery.

The main veins carrying de-oxygenated blood back to the heart for purification include:

Axillary vein: This vein drains into the subclavian vein.
Cephalic vein: This vein is found in the upper arm and branches at the elbow into the forearm region. It drains into the axillary vein.
Basilic vein: This vein runs opposite the cephalic vein, near the triceps muscle. It drains into the axillary vein.

Shoulder Separation

Shoulder Separation

Acromioclavicular joint (AC joint) dislocation or shoulder separation is one of the most common injuries of the upper arm. It involves separation of the AC joint and injury to the ligaments that support the joint.

Arthritis of the Shoulder

Arthritis of the Shoulder

The term arthritis literally means inflammation of a joint but is generally used to describe any condition in which there is damage to the cartilage. Damage of the cartilage in the shoulder joint causes shoulder arthritis.

Biceps Tendon Rupture at the Shoulder

Biceps Tendon Rupture at the Shoulder

Overuse and injury can cause fraying of the biceps tendon and eventual rupture. A biceps tendon rupture can either be partial, where it does not completely tear the tendon or complete, where the tendon completely splits in two and is torn away from the bone.

Shoulder Fracture

Shoulder Fracture

A break in a bone that makes up the shoulder joint is called a shoulder fracture.

The clavicle and end of the humerus closest to the shoulder are the bones that usually get fractured.

Frozen Shoulder (Adhesive Capsulitis)

Frozen Shoulder (Adhesive Capsulitis)

Frozen shoulder, also called adhesive capsulitis, is a condition characterized by pain and loss of motion in the shoulder joint. It is more common in older adults aged between 40 and 60 years and is more common in women than men.

Shoulder Impingement

Shoulder Impingement

Shoulder impingement is the inflammation of the tendons of the shoulder joint. It is one of the most common causes of pain in the shoulder. Shoulder impingement is also called swimmer’s shoulder, tennis shoulder or rotator cuff tendinitis.

Shoulder Labral Tear

Shoulder Labral Tear

Traumatic injury to the shoulder or overuse of the shoulder (throwing, weightlifting) may cause the labrum to tear. In addition, aging may weaken the labrum leading to injury.

Rotator Cuff Tear

Rotator Cuff Tear

A rotator cuff is a group of tendons in the shoulder joint that provides support and enables a wide range of motion. A major injury to these tendons may result in rotator cuff tears. It is one of the most common causes of shoulder pain in middle-aged and older individuals.

Shoulder Dislocation

Shoulder Dislocation

Sports that involve overhead movements and repeated use of the shoulder at your workplace may lead to sliding of the upper arm bone from the glenoid.

SLAP Tears

SLAP Tears

The term SLAP (superior –labrum anterior-posterior) lesion or SLAP tear refers to an injury of the superior labrum of the shoulder.

AC (Acromioclavicular) Arthritis

AC (Acromioclavicular) Arthritis

The acromioclavicular joint is part of the shoulder joint. It is formed by the union of the acromion, a bony process of the shoulder blade, and the outer end of the collar bone or clavicle. The joint is lined by cartilage that gradually wears with age as well as with repeated overhead or shoulder level activities such as basketball. The condition is referred to as AC arthritis or acromioclavicular arthritis.

From nonsurgical treatment options to minimally invasive surgical techniques, the physicians at the Hinsdale Orthopaedics take a multi-disciplined approach to expertly treat the broad range of shoulder conditions that can occur at any stage of life. Once the proper diagnosis has been made, you and your physician will decide the best course of treatment.

Non-Surgical Treatment

Many shoulder problems may be treatable without surgery. The surgeons at Hinsdale Orthopaedics maintain a philosophy that surgery should be reserved as a last resort when all other measures have proven unsuccessful in returning patients to an active lifestyle. Fortunately, there are several nonsurgical treatment options to help reduce shoulder pain such as exercise, physical therapy, and Cortisone treatments.

Surgical Treatment

Shoulder Arthroscopy

Shoulder Arthroscopy

Arthroscopy is a minimally invasive diagnostic and surgical procedure performed for joint problems. Shoulder arthroscopy is performed using a pencil-sized instrument called an arthroscope.

Shoulder Stabilization

Shoulder Stabilization

Shoulder stabilization surgery is performed to improve stability and function to the shoulder joint and prevent recurrent dislocations. It can be performed arthroscopically, depending on your particular condition, with much smaller incisions.

Rotator Cuff Repair

Rotator Cuff Repair

Surgery to repair the rotator cuff has traditionally been done through a large shoulder incision, about 6-10cm long, and the muscle over the rotator cuff was separated.

Shoulder Labrum Reconstruction

Shoulder Labrum Reconstruction

The labrum is a ring of fibrous cartilage surrounding the glenoid, which helps in stabilizing the shoulder joint. The biceps tendon is attached inside the shoulder joint at the superior labrum of the joint.

SLAP Repair

SLAP Repair

A superior labrum anterior and posterior tear or SLAP tear is an injury to the labrum. This injury may also involve the biceps tendon, which is attached to the top part of the labrum.