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The shoulder is comprised of the clavicle (collarbone), scapula (shoulder blade), and humerus (upper arm bone), as well as numerous muscles, ligaments, and tendons. We utilize our shoulders for both mobility and stability, including lifting, pushing, and pulling. The shoulder is a common source of aches and pains, often the result of repetitive motion used in sports, at work, or during daily activities. Orthopedic injuries and conditions associated with shoulder discomfort range from tendinitis, arthritis, and bursitis to fractures, rotator cuff injuries, and instabilities. To read more about shoulder conditions, click here.

Shoulder Anatomy

At OrthoNorCal Orthopedic Specialists, our specialty-trained and experienced shoulder surgeons are recognized as leaders in the diagnosis and treatment of shoulder injuries and conditions. Common surgical procedures our shoulder surgeons perform include arthroscopic rotator cuff repair, arthroscopic labral repair, total shoulder replacement, reverse total shoulder replacement, complex fracture repair, biceps tendon repair, and shoulder resurfacing among many other techniques.

  • 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 Joint Replacement

    Total shoulder replacement surgery is performed to relieve symptoms of severe shoulder pain and disability due to arthritis.

  • Revision Shoulder Replacement

    Total shoulder replacement is the replacement of the head of the humerus (upper arm bone) and the glenoid cavity (cavity of the shoulder blade) into which the humerus fits, with artificial prostheses to relieve pain, swelling, and stiffness caused due to damage of cartilage at the articulating surfaces.

  • Reverse Shoulder Replacement

    Conventional surgical methods such as total shoulder joint replacement are not very effective in the treatment of rotator cuff arthropathy.

  • Minimally Invasive Shoulder Joint Replacement

    Shoulder joint replacement is a surgical procedure that replaces damaged bone surfaces with artificial humeral and glenoid components to relieve pain and improve functional ability in the shoulder joint.

  • Rotator Cuff Repair

    The rotator cuff is a group of 4 muscles in the shoulder joint including the supraspinatus, infraspinatus, teres minor, and subscapularis. These muscles originate in the scapula and attach to the head of the humerus through tendons.

  • SLAP Repair

    A SLAP repair is an arthroscopic shoulder procedure to treat a specific type of injury to the labrum called a SLAP tear.

  • Latarjet Procedure

    The shoulder joint provides a wide range of movement to the upper extremity, but overuse or trauma can cause instability to the joint.

  • 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.

  • 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.

  • 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).

  • SC Joint Injury Reconstruction

    The sternoclavicular (SC) joint is the joint between the breastbone (sternum) and the collar bone (clavicle). Injuries to this joint are called sternoclavicular joint injuries and can include stretching or tearing of the ligaments.

  • Arthroscopic Bankart Repair

    The labrum can sometimes tear during a shoulder injury. A specific type of labral tear that occurs when the shoulder dislocates is called a Bankart tear.

  • Shoulder Labrum Reconstruction

    Traumatic injury to the shoulder or overuse of the shoulder by excessive throwing or weightlifting can cause a labral tear. In addition, the aging process may weaken the labrum, leading to injury secondary to wear and tear.

  • 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.

  • 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.

  • Shoulder Resurfacing

    The shoulder is an active joint is prone to injuries and may also get affected by conditions such as arthritis, which results in impaired functioning and related discomfort.

  • 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.

  • 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”.

  • Periprosthetic Shoulder Fracture Fixation

    A periprosthetic shoulder fracture is a fracture that occurs in the bone adjacent to a shoulder prosthesis.

  • Arthroscopic Superior Capsular Reconstruction (SCR)

    Superior Capsular Reconstruction is a surgical procedure to repair massive, irreparable rotator cuff tears. The surgery involves reconstruction of the superior capsule of the shoulder joint using an autograft (tissue from the same person) or an allograft (tissue from a donor).

  • 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.

  • Intraarticular Shoulder Injection

    The shoulder is prone to different kinds of injuries and inflammatory conditions. An intraarticular shoulder injection is a minimally invasive procedure to treat pain and improve shoulder movement.

  • 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.

  • 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.

  • Triceps Repair

    Triceps repair is a surgical procedure that involves the repair of a ruptured (torn) triceps tendon. A tendon is a tough band of fibrous tissue which connects muscle to bone and works together with muscles in moving your arms, fingers, legs, and toes.

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.
  • American Orthopaedic Society for Sports Medicine
  • American Association for Hand Surgery
  • American Academy Of Orthopaedic Surgeons
  • The American Board of Pediatrics
  • North American Spine Society
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