Comprehensive Guide to Shoulder Anatomy and Conditions
Do you suffer from shoulder problems or conditions? Whether it’s an old sports injury that still lingers, a recent injury that is causing you problems, or simply wear and tear, suffering from a shoulder condition is painful and debilitating.
To help you discuss shoulder conditions and treatment options with your surgeon, here’s a breakdown of the anatomy of the shoulder.
- Anatomy
- Conditions
- Procedures
Shoulder Anatomy
The shoulder is the most flexible joint in the body, which enables it to perform a wide range of movements, including: forward flexion, abduction, adduction, external rotation, internal rotation, and 360-degree circumduction. This versatility comes at a price, because the shoulder joint is the most insecure joint of the body. Ligaments, muscles, tendons, and bones provide stability and support, but if any of those become damaged or injured, it can be extremely painful and debilitating
Bones of the Shoulder
The shoulder joint is a ball and socket joint made up of three bones:
Humerus
The humerus, or upper arm bone, forms the ball of the shoulder joint. The head of the humerus fits into an irregular shallow cavity in the scapula called the glenoid cavity. The two bones together form the glenohumeral joint, which is the main joint of the shoulder.
Scapula
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.
Clavicle
The clavicle, or collarbone, is an S-shaped bone that connects the scapula to the sternum (or breastbone). 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. Articular cartilage enables smooth movement, reduces pressure, and acts as a shock absorber during movement of the shoulder bones. The glenoid labrum provides extra stability, and increases the depth and surface area of the glenoid cavity, providing a more secure fit.
Ligaments of the Shoulder
Ligaments are thick strands of fibers that connect one bone to another. The shoulder has four types of ligaments:
- Coracoclavicular ligaments connect the collarbone to the shoulder blade at the coracoid process.
- Acromioclavicular ligament connects the collarbone to the shoulder blade at the acromion process.
- Coracoacromial ligament connects the acromion process to the coracoid process.
- Glenohumeral ligaments connect the head of the arm bone to the glenoid cavity of the shoulder blade, providing stability.
Muscles of the Shoulder
The rotator cuff is a group of four muscles that form a sleeve around the humeral head and glenoid cavity, providing stability and 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 join muscle to bone allowing the muscle to control the movement of the bone or joint. There are two groups of tendons in the shoulder joint:
- Bicep tendons are the two tendons that join the bicep muscle of the upper arm to the shoulder.
- Rotator cuff tendons are four tendons that join the head of the humerus to the muscles of the rotator cuff.
Nerves of the Shoulder
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 and include the musculocutaneous, axillary, radial, ulnar, and median nerves.
Blood Vessels of the Shoulder
The subclavian artery supplies oxygenated blood to the shoulder region. As it enters the region of the armpit, it is called the axillary artery as it enters the region of the armpit and the brachial artery further down the arm.
Three veins carrying deoxygenated blood back to the heart:
- The axillary vein drains into the subclavian vein.
- The cephalic vein branches at the elbow into the forearm region and drains into the axillary vein.
- The basilic vein runs opposite the cephalic vein, near the triceps muscle. It drains into the axillary vein.
Now that you know the anatomy of the shoulder, see how we’re prepared to help solve your shoulder problems and conditions.
Rotator Cuff Repair
Rotator cuff tears are commonly caused by acute injuries or degenerative changes that occur slowly with age or overuse. Orthopedic Institute of North Texas (OINT) provides diagnosis and individualized nonoperative and operative treatments for the shoulder including rotator cuff repair in Baylor Frisco.
SLAP Repair
Repeated use of the shoulder while throwing or a fall onto the shoulder can result in a SLAP (superior labrum anterior and posterior) tear or injury. Orthopedic Institute of North Texas (OINT) provides diagnosis and individualized nonoperative and operative treatments for the shoulder including SLAP repair in Baylor Frisco.
Arthroscopic Bankart Repair
Young people who have sustained a dislocation of the shoulder may experience a specific type of labral tear called a Bankart tear. The condition usually occurs during a shoulder injury. Orthopedic Institute of North Texas (OINT) provides diagnosis and individualized nonoperative and operative treatments for the shoulder including arthroscopic Bankart repair in Baylor Frisco.
Arthroscopic Frozen Shoulder Release
An arthroscopic frozen shoulder release is a minimally-invasive shoulder surgery performed to relieve pain and restore normal function using a special instrument called an “arthroscope”.
Shoulder Stabilization
Frequent dislocations of the shoulder joint can lead to chronic shoulder instability. Surgery to stabilize the shoulder may be recommended when conservative treatment options fail.
Latarjet Procedure
The Latarjet procedure is an advanced procedure to treat shoulder instability caused by lack of bony support in the shoulder joint. Orthopedic Institute of North Texas (OINT) provides diagnosis and individualized nonoperative and operative treatments including the Latarjet procedure in Baylor Frisco.
Shoulder Joint Replacement
Arthritis of the shoulder can cause pain, swelling and stiffness in the joint. The condition is treated by removing the damaged articulating parts and replacing them with prostheses. Orthopedic Institute of North Texas (OINT) provides expert diagnosis and individualized non-operative and operative treatments for the shoulder including shoulder joint replacement in Baylor Frisco.
Reverse Shoulder Replacement
Individuals with rotator cuff tear arthropathy (occurrence of shoulder arthritis and rotator cuff tear), a fully torn rotator cuff that is difficult to repair or prior failed shoulder replacement are candidates for reverse shoulder replacement.
Minimally Invasive Shoulder Joint Replacement
The shoulder is a ball and socket joint that allows various arm movements. The head of the upper arm bone (humerus) articulates with the glenoid cavity of the shoulder bone (scapula). The two articulating surfaces of the bones are covered with cartilage which prevents friction between the moving bones.
Simpliciti Canal-Sparing Total Shoulder Arthroplasty
When the shoulder joint is affected by arthritis, the cartilage lining the articulating bones breaks down. This causes the bones to rub against each other leading to pain and inflammation.
Revision Shoulder Replacement
Persistent pain, infection, stiffness, weakness, instability, hardware loosening, malposition or fracture after a total shoulder replacement may necessitate revision surgery. Orthopedic Institute of North Texas (OINT) provides expert diagnosis and individualized nonoperative and operative treatments for the shoulder including revision shoulder replacement in Baylor Frisco.
Am I A Candidate For Shoulder Replacement?
Shoulder replacement is a surgical procedure where the damaged parts of your shoulder are removed and replaced with artificial parts known as prostheses.
Failed Shoulder Surgery
Failed shoulder surgery is a surgery that did not meet expectations and resulted in recurring pain or other unwanted symptoms. All surgeries are associated with risks, some have a higher risk than others. The most commonly reported failed shoulder surgeries include rotator cuff repairs and shoulder stabilization for shoulder instability.
Shoulder Fracture Care
A break in the bone that makes up the shoulder joint is called a shoulder fracture. The clavicle (collarbone) and end of the humerus (upper arm bone) closest to the shoulder are the bones that usually are fractured. The scapula, or shoulder blade, is not easily fractured because of its protective cover of surrounding muscles and chest tissue.
Orif Of The Scapula Fractures
Scapular (shoulder blade) fractures are usually the result of intense trauma such as a high-speed motor vehicle accident, a fall from a height onto one’s back or a fall on an outstretched arm. Orthopedic Institute of North Texas (OINT) provides diagnosis and individualized nonoperative and operative treatments for the shoulder including ORIF of scapular fractures in Baylor Frisco.
Ultrasound-guided Shoulder Injections
An ultrasound is a common imaging technique that employs high-frequency sound waves to create images of organs and other internal structures of the body. These images provide valuable information about the underlying pathology of tissues and assists with diagnosis and planning the treatment of a condition.
Proximal Biceps Tenodesis
Proximal biceps tenodesis is the surgical reattachment of a torn proximal biceps tendon, which connects the upper part of your biceps muscle to the shoulder.
Arthroscopic Acromioplasty
Acromioplasty is the surgical removal of a small part of the surface of the acromion (bony process on your shoulder blade). The shoulder joint is made up of a ball and socket joint, where the head of the humerus (upper arm bone) articulates with the socket of the scapula (shoulder blade), which is called the glenoid.
Acromioclavicular (Ac) Joint Reconstruction
The acromioclavicular (AC) joint is one of the joints present within your shoulder. It is formed between a bony projection at the top of the shoulder blade (acromion) and the outer end of the clavicle (collarbone). The joint is enclosed by a capsule and supported by ligaments.
Sternoclavicular Joint Reconstruction
Sternoclavicular joint reconstruction is a surgical procedure employed to repair and restore full function of a damaged sternoclavicular joint.
Latissimus Dorsi Tendon Transfer
Latissimus dorsi tendon transfer is a surgical procedure performed to reconstruct the irreparable rotator cuff tears in your shoulder. The procedure typically involves detaching the latissimus dorsi tendon from its original location and transferring it to the shoulder to repair the rotator cuff.
Distal Clavicle Excision
Distal clavicle excision is a procedure which involves removal of the outer end of the clavicle (collarbone) to treat shoulder pain and disability due to arthritis or impingement.
Pectoralis Major Tears/Repairs
The pectoralis muscle is a large fan-shaped muscle comprised of the pectoralis major and pectoralis minor muscles that stretch from the armpit to the collarbone and down across the lower chest region on both sides of the chest. The two sides of the chest connect at the breastbone or sternum.
Bony Instability Reconstruction Of The Shoulder
The shoulder is the most flexible joint in the body. Injury and trauma can tear or stretch the labrum and/or ligaments, causing loosening and instability of the shoulder joint which can lead to partial or complete dislocation of the joint.
Open Glenoid Bone Grafting
The glenoid, also called the glenoid cavity or glenoid fossa, is a shallow depression in the shoulder blade (scapula) that connects the upper arm bone (humerus) with the collar bone (clavicle).
Revision Open Labral Repair (Revision Bankart)
Revision open labral repair, also known as a revision Bankart surgery, is an open surgery performed to stabilize the shoulder joint after an unsuccessful primary labral repair surgery that may have been done either arthroscopically or as open surgery.
Lower Trapezius Tendon Transfer
Lower trapezius tendon transfer is a surgical procedure to treat massive, irreparable, posterosuperior rotator cuff tears of the shoulder.
ORIF of the Clavicle Fractures
A clavicle fracture refers to a broken collarbone and is a common injury associated with contact sports such as football and martial arts, as well as impact sports such as motor racing. A direct blow over the shoulder, a fall on an outstretched arm, or a motor vehicle accident may also cause the clavicle bone to break.
Subacromial Decompression
Subacromial decompression is a surgical procedure performed for the treatment of a condition called shoulder impingement. In shoulder impingement, the degree of space between the rotator cuff tendon and shoulder blade is decreased due to irritation and swelling of the bursa or due to development of bone spurs.
Periprosthetic Shoulder Fracture Fixation
A periprosthetic shoulder fracture is a fracture that occurs in the bone adjacent to a shoulder prosthesis.
Non-surgical Shoulder Treatments
Shoulder injuries can often be treated by non-surgical methods including the following:
Shoulder Pain
Pain in the shoulder may suggest an injury, which is more common in athletes participating in sports such as swimming, tennis, pitching, and weightlifting. The injuries are caused due to the over usage or repetitive motion of the arms.
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. Inflammation is the body's natural response to injury. The warning signs that inflammation presents are redness, swelling, heat, and pain.
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.
Massive Retracted Rotator Cuff Tear
The rotator cuff consists of 4 muscles which stabilize the shoulder joint and enable certain arm movements. The muscles of the rotator cuff include:
Frozen Shoulder
Frozen shoulder, also called adhesive capsulitis, is a condition in which you experience pain and stiffness in your shoulder. The symptoms appear slowly, worsen gradually and usually take one to three years to resolve on their own.
Shoulder Dislocation
The shoulder joint is a ball and socket joint. A ball at the top of the upper arm bone (humerus) fits neatly into a socket, called the glenoid, which is part of the shoulder blade (scapula). The glenoid is surrounded by a ring of fibrous cartilage called the labrum for stabilization of the shoulder joint.
Shoulder Instability
Shoulder instability is a chronic condition that causes frequent dislocation of the shoulder joint.
Shoulder Impingement
The shoulder is a ball-and-socket joint. The ball-shaped end of the upper arm bone (humerus) fits neatly into a socket, called the glenoid, which is part of the shoulder blade or scapula.
Shoulder Trauma
Shoulder injuries most commonly occur in athletes participating in sports such as swimming, tennis, pitching, and weightlifting. The injuries are caused due to the over usage or repetitive motion of the arms.
SLAP Tears
The shoulder joint is a ball and socket joint. A ball at the top of the upper arm bone (humerus) fits neatly into a socket, called the glenoid, which is part of the shoulder blade (scapula). The glenoid is surrounded by a ring of fibrous cartilage called the labrum for stabilization of the shoulder joint. The biceps tendon attaches inside the shoulder joint at the superior labrum of the shoulder joint.
Shoulder Labral Tear
The shoulder joint is a ball and socket joint. A ball at the top of the upper arm bone (humerus) fits neatly into a socket, called the glenoid, which is part of the shoulder blade (scapula). The glenoid is surrounded by a ring of fibrous cartilage called the labrum for stabilization of the shoulder joint. The biceps tendon attaches inside the shoulder joint at the superior labrum of the shoulder joint.
Baseball And Shoulder Injuries
The shoulder is a ball and socket joint, formed by the bone of the upper arm (humerus), which articulates with the shoulder blade in a cavity called the glenoid fossa.
Overhead Athlete's Shoulder
An overhead athlete is at increased risk of injury due to the mechanism associated with rapid shoulder elevation, external rotation, and abduction. An overhead throwing motion is an intricate and skillful movement that presents a special challenge of needing the glenohumeral joint to surpass its physiologic limits during overhead sports activities.
Little League Shoulder
The upper arm bone is called the humerus. It forms the shoulder joint at the upper end and elbows joint at the lower end. In children, the bone continues from a region called the growth plate, which is found at the ends of the bone. This is a region of cartilage cells, which are still soft. In time, they mature and harden to form the adult bone.
Clavicle Fracture
The break or fracture of the clavicle (collarbone) is a common sports injury associated with contact sports such as football and martial arts, as well as impact sports such as motor racing. A direct blow over the shoulder that may occur during a fall on an outstretched arm or a motor vehicle accident may cause the clavicle bone to break.
Shoulder Fracture
The shoulder is the most flexible joint in the body, enabling a wide range of movements. It is a ball-and-socket joint made up of three bones, namely the humerus (upper arm bone), scapula (shoulder blade) and clavicle. The head of the humerus articulates with the socket of the scapula called the glenoid cavity.
Fracture Of The Shoulder Blade (Scapula)
The scapula (shoulder blade) is a flat, triangular bone providing attachment to the muscles of the back, neck, chest and arm. The scapula has a body, neck and spine portion.
Glenoid Fractures
The shoulder joint is a ball and socket joint. A ball at the top of the upper arm bone (humerus) fits neatly into a socket, called the glenoid, which is part of the shoulder blade (scapula). The glenoid is surrounded by a ring of fibrous cartilage called the labrum for stabilization of the shoulder joint.
Proximal Humerus Fractures
The humerus is the bone that forms the upper arm. It articulates with the glenoid cavity of the scapula (shoulder blade) to form the shoulder joint and with the lower arm bones – the ulna and radius – to form the elbow joint. The proximal humerus is the upper end of the arm bone that forms the shoulder joint.
Periprosthetic Shoulder Infection
A periprosthetic shoulder joint infection is a very rare, but devastating complication of shoulder replacement surgery characterized by infection of the tissues surrounding your shoulder prosthesis.
Periprosthetic Shoulder Fracture
A periprosthetic shoulder fracture is a fracture that occurs in the bone adjacent to a shoulder prosthesis.
Subacromial Impingement Syndrome
SAIS is the inflammation and irritation of your rotator cuff tendons. This occurs when the tendons rub against the outer end of the shoulder blade (the acromion) while passing through the subacromial space during shoulder movement.
Posterior Shoulder Instability
Posterior shoulder instability, also known as posterior glenohumeral instability, is a condition in which the head of the humerus (upper arm bone) dislocates or subluxes posteriorly from the glenoid (socket portion of the shoulder) as a result of significant trauma.
Anterior Shoulder Instability
Anterior shoulder instability, also known as anterior glenohumeral instability, is a condition in which damage to the soft tissues or bone causes the head of the humerus (upper arm bone) to dislocate or sublux from the glenoid fossa, compromising the function of the shoulder.
Subluxation
The shoulder is a highly mobile ball and socket joint. The ball of the upper arm bone (humerus) is held in place at the socket (glenoid) of the shoulder blade (scapula) by a group of ligaments. A partial dislocation of the shoulder joint is termed as a subluxation.
Snapping Scapula
Snapping scapula or snapping scapula syndrome is also known as scapulothoracic syndrome or scapulocostal syndrome. It is a condition characterized by painful clicking, snapping, or grinding of the shoulder blade. The sound occurs as a result of rubbing of soft tissues between the thoracic wall and the scapula.
Bicep Tendon Rupture At Shoulder
The biceps muscle is present on the front of your upper arm and functions to help you bend and rotate your arm. The biceps tendon is a tough band of connective fibrous tissue that attaches your biceps muscle to the bones in your shoulder on one side and the elbow on the other side.
Sternoclavicular Joint (SC joint)
The sternoclavicular joint is the joint between the breastbone (sternum) and the collar bone (clavicle). The SC joint is one of the 4 joints that complete the shoulder and is the only joint that links the arm to the body.
Proximal Biceps Tendinitis
Proximal biceps tendinitis is the irritation and inflammation of the biceps tendon at the shoulder joint. The biceps muscle is the muscle of the upper arm which is necessary for the movement of the shoulder and elbow. It is made of a ‘short head’ and a ‘long head’ which function together.
Internal Impingement Of The Shoulder
Internal shoulder impingement can be described as a pathological condition resulting from repetitive impingement of the internal surface of the rotator cuff by the bones at the back of the glenohumeral joint.
Rotator Cuff Re-tear
The rotator cuff is a group of tendons and muscles in the shoulder joint providing support and enabling a wide range of shoulder motion. Injury to the rotator cuff may occur due to pressure on the rotator cuff from part of the shoulder blade (scapula).
AC Joint Separation
AC joint separation, also known as shoulder separation, is a condition characterized by damage to the ligaments that connect the acromion to the collar bone. As a result, the bones do not line up properly, causing joint pain and instability.
Shoulder Tendonitis
Shoulder tendonitis is a condition characterized by inflammation of the tendons which connect the muscles to the shoulder bones. Tendonitis of the rotator cuff tendons is known as rotator cuff tendonitis. If the biceps tendon is affected, the condition is known as bicipital tendonitis.
Throwing Injuries Of The Shoulder
Throwing injuries of the shoulder are injuries sustained as a result of trauma by athletes during sports activities that involve repetitive overhand motions of the arm as in baseball, American football, volleyball, rugby, tennis, track and field events, etc.
Acromioclavicular (AC) 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.
Rotator Cuff Calcification
Rotator cuff calcification is the abnormal accumulation of calcium deposits in rotator cuff muscles and tendons. The rotator cuff is a group of 4 muscles and tendons in the shoulder joint that join the head of the humerus to the shoulder. It forms a sleeve around the humeral head and glenoid cavity, providing additional stability to the shoulder joint while enabling a wide range of mobility.
Shoulder Disorders
The shoulder is the most flexible joint in the body that enables a wide range of movements. Aging, trauma or sports activities can cause injuries and disorders that can range from minor sprains or strains to severe shoulder trauma.
Partial Rotator Cuff Tear
A partial rotator cuff tear is an incomplete tear that involves damage to a part of the tendon. The tear can be at the top, bottom or inner side of the tendon and does not go all the way through the tendon completely.
Bicep Tendon Rupture
The biceps muscle is located in the front side of your upper arm and functions to help you bend and rotate your arm.
Shoulder Labral Tear with Instability
The shoulder consists of a ball-and-socket joint formed by the upper end of the humerus (upper arm bone) and a cavity in the shoulder blade called the glenoid. The glenoid cavity is surrounded by a rim of cartilage called the labrum.
Proximal Biceps Tendon Rupture
The biceps muscle is the muscle of the upper arm which is necessary for the movement of the shoulder and elbow. It is made of a ‘short head’ and a ‘long head’ which function together. These are connected to the shoulder joint by two tendons called the proximal biceps tendons and to the elbow joint by a single distal biceps tendon.
Long Head Biceps Tendon Rupture
Your biceps muscle has two heads, a long head, and a short head, which are both attached to the shoulder. The long head of the biceps tendon is a tough band of connective fibrous tissue that attaches the long head of the biceps to the top of the shoulder socket.
Multidirectional Instability of the Shoulder
The shoulder consists of a ball and socket joint where the rounded end of the humerus (upper arm bone) fits into a socket (glenoid cavity) formed by the shoulder blade. The joint is stabilized by the surrounding capsule, ligaments, and tendons of the rotator cuff muscles. Shoulder instability results when the humerus is not held firmly within the socket and moves away from the glenoid cavity.
Hill-sachs Lesion
Your shoulder consists of a ‘ball-and-socket joint’. The humerus (upper arm bone) has a rounded head (ball) that is attached to the glenoid cavity (socket) in the shoulder blade. Certain injuries can cause dislocation of the joint and damage to the humeral head. Damage to the back and outer portion of the humeral head can result in a defect called a Hill-Sachs lesion.
Ac Joint Dislocation/acromioclavicular Joint Dislocation
A dislocation occurs when the ends of your bones are partially or completely moved out of their normal position in a joint. A partial dislocation is referred to as a subluxation, whereas a complete separation is referred to as a dislocation.
Calcification Tendinitis
Calcification tendinitis is a problem with the shoulder’s tendons and muscles. This condition occurs due to the formation of calcium deposits in the tendons (tissue which attaches muscle to bone) of the rotator cuff (a group of muscles and tendons stabilizing the shoulder).
Rotator Cuff Pain
The rotator cuff consists of a group of tendons and muscles that surround and stabilize the shoulder joint. These tendons allow a wide range of movement of the shoulder joint across multiple planes. Irritation or injury to these tendons can result in rotator cuff pain.
Anatomic Shoulder Replacement
Arthritis of the shoulder can cause pain, swelling and stiffness in the joint. The condition is treated by removing the damaged articulating parts and replacing them with prostheses.