Logo

    Related Topics

    From Musculoskeletal System

    Wormian Bones
    Sutural bones in the skull.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Carpals (8 bones)
    8 wrist bones.
    Pectoralis Major
    Chest muscle responsible for shoulder movement.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Saddle Joints
    e.g., thumb joint
    Rectus Abdominis
    Abs muscle that flexes the trunk.
    Anterior Longitudinal Ligament
    Spinal ligament running along the front of the vertebral column.
    Rotator Cuff Muscles
    Supraspinatus, Infraspinatus, Teres Minor, Subscapularis.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Flexor Tendons
    Tendons that help flex the fingers and toes.
    Buccinator
    Muscle that helps with chewing and blowing air out.
    Extensor Tendons
    Tendons that help extend the fingers and toes.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Synchondroses
    Cartilaginous joints where bones are connected by hyaline cartilage.
    Hyoid Bone
    U-shaped bone in the neck that supports the tongue.
    Triceps Brachii
    Muscle responsible for elbow extension.
    Acromioclavicular Ligament
    Ligament that connects the acromion to the clavicle.
    Fibula
    Smaller bone in the lower leg, located alongside the tibia.
    Parietal Bones
    Bones forming the sides and roof of the skull.
    Ribs (12 Pairs)
    12 pairs of bones that form the sides of the thoracic cage.
    Gastrocnemius
    Calf muscle responsible for plantarflexion of the foot.
    Vertebral Column
    Spinal column consisting of vertebrae.
    Quadriceps Tendon
    Tendon that connects the quadriceps to the patella.
    Interspinous Ligament
    Spinal ligament between adjacent vertebral spinous processes.

    Coracoacromial Ligament

    Reviewed by our medical team

    Ligament that connects the acromion to the coracoid process.

    1. Overview

    The coracoacromial ligament is a strong, triangular band of connective tissue located in the shoulder. It connects the coracoid process to the acromion, both of which are projections of the scapula. This ligament forms part of the coracoacromial arch, a protective arch over the head of the humerus, preventing its upward displacement. Although it does not directly stabilize the glenohumeral joint, it plays a crucial role in maintaining the structural integrity of the shoulder and preventing impingement.

    2. Location

    The coracoacromial ligament is found in the superior aspect of the shoulder, forming a roof over the glenohumeral joint:

    • Proximally: Attaches to the lateral border of the coracoid process.

    • Distally: Inserts onto the medial border of the acromion process.

    • Orientation: Extends obliquely over the head of the humerus, forming a protective arch along with the acromion and coracoid process.

    3. Structure

    The coracoacromial ligament is composed of dense regular connective tissue and has the following structural characteristics:

    • Shape: Flat and triangular, with a broad base at the acromion and an apex at the coracoid process.

    • Fibers: Run obliquely, blending with the deep fascia of the shoulder and sometimes with the deltoid or trapezius muscle fascia.

    • Coracoacromial arch: Along with the acromion and coracoid process, it forms a bony-ligamentous arch over the humeral head.

    4. Function

    The coracoacromial ligament serves important mechanical and protective functions:

    • Prevents superior dislocation: Acts as a barrier to upward displacement of the humeral head during shoulder movements.

    • Supports the coracoacromial arch: Maintains the integrity of the arch, which protects the rotator cuff and glenohumeral joint from direct trauma.

    • Limits excessive motion: Assists in restricting superior translation of the humerus.

    5. Physiological role(s)

    Though not a dynamic stabilizer, the coracoacromial ligament has several physiological roles:

    • Passive restraint: Provides a static check-rein to upward movement of the humeral head, especially during deltoid contraction.

    • Force redirection: Helps distribute forces exerted by surrounding muscles and tendons over the superior shoulder.

    • Anatomical roof: Forms a part of the shoulder's subacromial space, influencing the biomechanics of the rotator cuff tendons and bursa.

    6. Clinical Significance

    The coracoacromial ligament is implicated in various shoulder pathologies, particularly in impingement syndromes:

    • Subacromial impingement syndrome:

      • The coracoacromial arch can impinge on the supraspinatus tendon or subacromial bursa during arm elevation, causing pain and reduced mobility.

      • Thickening or ossification of the ligament may contribute to narrowing of the subacromial space.

    • Rotator cuff tears:

      • Chronic impingement against the ligament can cause wear and eventual tearing of the supraspinatus tendon.

    • Coracoacromial ligament release:

      • In severe or recurrent impingement cases, partial resection of the ligament may be performed surgically to decompress the subacromial space.

    • Shoulder instability evaluation:

      • Though it does not directly stabilize the glenohumeral joint, an intact coracoacromial arch is a secondary restraint to superior translation in the event of rotator cuff failure.

    Did you know? The tibia is the second largest bone in the body after the femur.