ARTHROLOGY - SYNDESMOLOGY

• Arthrology is the study of joints
• Arthro-


  Refers to joints, from the Greek (ἄρθρον) arthron
• Functional classification of joints


  • Synarthrosis: little/no mobility, mostly fibrous joints
  • Amphiarthrosis: slight mobility, mostly cartilaginous joints
  • Diarthrosis: freely movable, synovial joints

  
• Structural classification of joints


  • Fibrous joints: joined with dense fibrous connective tissue
  • Cartilaginous joints: joined by cartilage
  • Synovial joints: not directly joined, bones share synovial cavity

  
• Most of the joints in the body are synovial joints

  
• Synovial joints


  • Joint faces are individually covered with hyaline cartilage
  • Joint capsule surrounds the side of the joint

  
• Structures required for synovial joints

  • Joint cavity
  • Articular cartilage
  • Articular capsule
  • Articular ligaments

  
• Joint cavity


  The space-cavity between the cartilage-covered surfaces and the inner face of the joint capsule, filled with synovial fluid
• Articular capsule


  Made of collagen fibers, completely covers the joint faces and joint space, in two layers
• Articular cartilage


  Hyaline cartilage that covers the joint faces of the bones

  
• Articular ligaments


  Connect the bones that make up the joint

  
• Bursae


  Small fluid-filled sacs that reduce friction between moving parts in joints
• Classification of synovial joints


  • Plane Joint
  • Hinge Joint or Ginglymus
  • Pivot Joint or Articulatio Trochoidea
  • Ellipsoid Joint or Condyloid Joint
  • Saddle Joint or Articulatio Sellaris
  • Ball-Socket Joint or Articulatio Spheroidea
  • Bicondylar Joint

  
• Ginglymus or Hinge Joint


  • Uni-axial synovial joint, moves on the transverse axis (flex-eks)
  • Example: Humero-ulnar joint

  
• Plane Joint


  • One joint face is straight, the other matches it, only limited sliding movements
  • Example: Intercarpal joint
• Pivot Joint or Articulatio trochoidea


  • Axis extends in the vertical direction, makes a rotational movement
  • Examples: Proximal-distal radioulnar joint, atlantoaxial median joint

  
• Ellipsoidal Joint


  • Joint faces are oval, with a condyle on one side and a face that fits on the other, moves in transverse and sagittal axes
  • Examples: Metacarpophalangeal joint, Atlantooccipital joint, radiocarpal joint

  
• Saddle Joint or Articulatio sellaris


  • Both joint faces are concave in one direction, and convex in the other, has sagittal and transverse axes
  • Example: Carpometacarpal joint of the thumb

  
• Ball-and-Socket Joint or Spheroidal Joint (enarthrosis)


  • Moves in 3 main axes: vertical, sagittal and transverse, has a convex joint face in the form of a sphere and a concave joint face in the form of a pit
  • Examples: shoulder joint, hip joint

  
• Bicondylar Joint


  • The convex joint face is in the form of 2 condyles, and the concave joint face is in the form of a slightly hollow, joint space is divided partially or completely by 2 meniscus or discus, movement occurs in the transverse axis (flexion-extension, slightly rotation), restricted rotational motion around the vertical axis
  • Examples: Knee joint, temporomandibular joint