Joints of the Upper Limbs

• Joints of the upper limbs refers to the articulations that connect the bones in the upper extremities.

Introduction

• A joint is where two or more bones articulate, with classification depending on the tissues in between.
• Joint classifications include cartilaginous, fibrous, and synovial joints.
• Cartilaginous joints are further divided into primary and secondary types.
• The 1st rib and sternum are examples of primary cartilaginous joints.
• The pubic symphysis and intervertebral discs are examples of secondary cartilaginous joints.
• Fibrous joints are lined by fibrous tissue.
• Suture lines on the skull and the distal tibio-fibular joint are examples of fibrous joints.
• Synovial joints are lined by fibrocartilage and hyaline cartilage.
• The shoulder is an example of a synovial joint.

Synovial Joints

• Synovial joints can be categorized based on the shape of the articulating bones.
• The elbow and knee are hinge joints.
• The joints between tarsal bones are plane joints.
• The carpo-metacarpal joint is a saddle joint.
• The shoulder is a ball and socket joint.

Joints in the Upper Limbs

• Key joints in the upper limbs include the sternoclavicular, shoulder, elbow, acromio-clavicular, radio-ulnar, wrist, carpo-metacarpal, metacarpo-phalangeal, and interphalangeal joints.

Sternoclavicular Joint

• The sternoclavicular joint is a saddle joint that links the upper limb to the trunk.
• It involves articulation between the medial end of the clavicle and the manubrium of the sternum, plus the first costal cartilage.
• It's nerve supply is provided by the supraclavicular nerve and the nerve to subclavius.
• The internal thoracic artery provides arterial supply.
• This joint allows movements such as flexion, extension, adduction, and abduction.
• Dislocation, fracture, and osteoarthritis are examples of applied anatomy considerations.

Shoulder Joint

• The shoulder joint is a ball and socket joint that articulates the head of the humerus with the glenoid cavity of the scapula.
• Circumduction is the main movement it allows.
• Nerve supply comes from the axillary, lateral pectoral, and suprascapular nerves.
• Both anterior and posterior circumflex humeral arteries, along with the suprascapular artery, provide blood supply.
• Anterior dislocation and rotator cuff injuries are relevant clinical considerations.

Elbow Joint

• The elbow joint is a hinge joint that articulates the trochlear notch of the ulna, the capitulum of the humerus, and the head of the radius.
• Flexion and extension are the main movements.
• Nerve supply is provided by branches of the median, ulnar, radial, and musculocutaneous nerves.
• Branches from the brachial artery supply blood to the joint.
• Dislocation considerations are important for applied anatomy.

Acromio-Clavicular Joint

• The acromioclavicular joint is a plane joint that articulates the acromion of the scapula with the lateral end of the clavicle.
• Innervation is from the suprascapular and lateral pectoral nerves.
• Suprascapular and thoraco-acromial arteries provide arterial supply.
• Gliding and rotation are the movements.
• Dislocation is a key clinical consideration.

Radio-Ulnar Joint

• The radio-ulnar joint is a pivot joint that articulates the circumference head of the radius with the annular ligament and the radial notch on the ulna.
• Pronation and supination are enabled by this joint.
• The median, ulnar, musculocutaneous, and radial nerves provide nerve supply.
• Monteggia fracture is an important clinical aspect.
• Monteggia fracture is a fracture of the proximal ulna with dislocation of the radial head.

Wrist/Radio-Carpal Joint

• The wrist joint enables articulation between the distal end of the radius and the articular disc, plus the scaphoid, lunate, and triquetral bones.
• It allows flexion, extension, abduction, adduction, and circumduction.
• The radial and ulnar arteries supply blood.
• The radial, ulnar, and median nerves provide nerve supply.
• Avascular necrosis has clinical relevance.