Joints of the Upper Limb

Subcutaneous Olecranon Bursa

• Located in the subcutaneous connective tissue over the olecranon

Bicipitoradial Bursa

• Separates the biceps tendon from the anterior part of the radial tuberosity
• Reduces abrasion against the radial tuberosity

Proximal Radio-Ulnar Joint

• A pivot type of synovial joint
• Allows movement of the head of the radius on the ulna
• The head of the radius articulates with the radial notch of the ulna
• The radial head is held in position by the annular ligament of the radius
• The joint capsule encloses the joint and is continuous with that of the elbow joint
• The annular ligament attaches to the radial notch of the ulna, forming a collar around the head of the radius
• The articular cavity of the joint is continuous with that of the elbow joint

Joints of the Upper Limb

• Divided into four parts: pectoral region, brachial region, antebrachial region, and hand region
• Each region has different types and functions of joints

Joints in the Pectoral Region

• Sternoclavicular joint
• Acromioclavicular joint
• Glenohumeral joint

Sternoclavicular Joint

• A saddle type of synovial joint but functions as a ball-and-socket joint
• Divided into two compartments by an articular disc
• The articular disc serves as a shock absorber of forces transmitted along the clavicle from the upper limb
• Dislocation of the clavicle is rare, whereas fracture of the clavicle is common
• The sternal end of the clavicle articulates with the manubrium and the 1st costal cartilage
• The articular surfaces are covered with fibrocartilage
• The joint capsule surrounds the SC joint, including the epiphysis at the sternal end of the clavicle
• The joint capsule is attached to the margins of the articular surfaces, including the periphery of the articular disc
• A synovial membrane lines the internal surface of the fibrous layer of the joint capsule, extending to the edges of the articular surfaces
• The strength of the SC joint depends on its ligaments and articular disc
• Anterior and posterior sternoclavicular ligaments reinforce the joint capsule anteriorly and posteriorly
• The interclavicular ligament strengthens the capsule superiorly
• The costoclavicular ligament anchors the inferior surface of the sternal end of the clavicle to the 1st rib and its costal cartilage, limiting elevation of the pectoral girdle
• The SC joint is supplied by the internal thoracic and suprascapular arteries
• The SC joint is supplied by branches of the medial supraclavicular nerve and the nerve to the subclavius

Acromioclavicular Joint

• A plane type of synovial joint
• Located 2–3 cm from the “point” of the shoulder formed by the lateral part of the acromion