Types of Synovial Joints

Joints of the Head and Neck

• Skull sutures: coronal, sagittal, lambdoid, and squamous sutures
• Temporo-Mandibular joint: articulation between the temporal bone and the mandible
• Atlanto-Axial joint: pivot joint, allows for rotation of the head
• Cervical Intervertebral joint: articulation between the vertebrae in the neck

Joints of the Pectoral Girdle

• Sterno-clavicular Joint: synovial double-plane joint, articulation between the sternal end of the clavicle, the manubrium sterni, and the first costal cartilage
• Acromio-clavicular Joint: synovial plane joint, articulation between the acromion of the scapula and the lateral end of the clavicle
• Glenohumeral Joint: synovial ball and socket joint, articulation between the head of the humerus and the glenoid cavity of the scapula, permits movements such as flexion, extension, abduction, adduction, medial rotation, lateral rotation, and circumduction

Joints of the Forearm

• Elbow joint: synovial hinge joint, articulation between the trochlea and capitulum of the humerus and the trochlear notch of the ulna and the head of the radius, permits only flexion and extension
• Radio-Ulnar Joint: two joints, superior and inferior, united by the interosseous membrane
• Superior Radio-Ulnar Joint: synovial pivot joint, articulation between the head of the radius and the radial notch of the ulna, permits pronation and supination
• Distal Radio-Ulnar Joint: synovial pivot joint, articulation between the rounded head of the ulna and the ulnar notch on the radius, permits pronation and supination

Wrist Joint

• Radio-Carpal Joint: synovial ellipsoid joint, articulation between the distal end of the radius and the articular disc of the ulna, and the scaphoid, lunate, and triquetral bones, permits flexion, extension, abduction, and adduction

Joints of the Hands

• Intercarpal joints: between the carpal bones
• Carpometacarpal joints: between the carpal bones and the metacarpal bones
• Metacarpophalangeal joints: between the metacarpal bones and the phalanges
• Interphalangeal joints: between the phalanges

Joints of the Lower Limb

• Hip joint: synovial ball and socket joint, articulation between the head of the femur and the acetabulum, permits movements such as flexion, extension, abduction, adduction, lateral and medial rotation, and circumduction
• Knee joint: synovial hinge joint, articulation between the condyles of the femur and the tibia, and the patella and the femur

Synovial Joints

• Articular surfaces are lubricated by synovial fluid
• The capsule is strengthened by ligaments which unite the bones together
• Classified into different types based on the shape of the articulating bones and the type of movement:
  • Plane joints: flat articular surfaces, e.g. Acromioclavicular joint
  • Hinge joints: only flexion and extension are possible, e.g. Elbow, knee, and ankle joints
  • Pivot joints: central bony axis surrounded by a bony-ligamentous ring, only rotation is possible, e.g. Atlanto-axial joint and superior radioulnar joints
  • Condyloid joints: two different convex surfaces articulate with two concave surfaces, e.g. Metacarpophalangeal joints
  • Ellipsoid joints: elliptical convex articular surface fits into an elliptical concave articular surface, e.g. Wrist joint
  • Saddle joint: reciprocally concavo-convex articular surfaces, e.g. Carpometacarpal joint of the thumb
  • Ball and socket joints: ball-shaped convex surface fits into a socket-like concavity, e.g. Shoulder and hip joints