Arthrology: Support and Movement 2

Support and Movement 2: Arthrology

• Arthrology is the study of joints or articulations.
• It's derived from Greek words: arthron (joint) and logos (study).

Content

• Definition of joints
• Classification of joints (based on structure and function)
• Characteristics of synovial joints
• Joint disorders (Osteoarthritis and Rheumatoid Arthritis)

Definition

• Greek: arthron, joint, denoting a joint or articulation
• Greek: logos, study

Classification of Joints (Based on Structure)

• Fibrous Joints:
  • Allow very limited movements.
  • Bones are connected by fibrous tissue.
  • Types:
    • Sutures (skull): articulation by process & indentation, coronal suture binds frontal and parietal bones, fibrous connective tissue connects bones.
    • Gomphoses (teeth): conical process fits into a socket (e.g., roots of teeth into alveoli of maxillae and mandible).
    • Syndesmoses (distal tibiofibular joint): surface united by an interosseous ligament.
• Cartilaginous Joints:
  • Allow limited movement.
  • Bones are connected by cartilage.
  • Types:
    • Synchondroses (temporary): epiphyseal plate (youth), cartilage ossifies in adult life (e.g., epiphysis of child).
    • Symphyses (secondary): two bones joined by fibrocartilage (e.g., inter-body joints of the spine, pubic symphysis).
• Synovial Joints:
  • Most common type.
  • Bone ends covered by articular cartilage.
  • Joint cavity containing synovial fluid.
  • Articular capsule encloses joint cavity.
  • Synovial membranes secrete synovial fluid.
  • Types of synovial joints (based on movement): hinge, pivot, condylar, saddle, plane, ball-and-socket.

Classification of Joints (Based on Function)

• Synovial Joints:
  • Hinge (uniaxial): flexion and extension only (e.g., elbow, knee)
  • Pivot (uniaxial): rotary movement in one axis (e.g., C1/2, proximal radioulnar)
  • Condylar (ellipsoid, biaxial): angular movement in two directions (e.g., wrist, metacarpophalangeal joint)
  • Saddle (biaxial): saddle-shaped heads permit movement in two planes (e.g., carpometacarpal joint of thumb)
  • Plane (biaxial): gliding or sliding movements (e.g., intercarpal, facet of spine, superior tibiofibular, acromioclavicular)
  • Ball-and-socket (multiaxial): movement in all directions (e.g., hip, glenohumeral)

Joint Disorders

• Osteoarthritis (OA):
  • Degenerative and progressive loss of joint cartilage.
  • Factors: aging, obesity, joint irritation, muscle weakness, wear/abrasion.
  • Common reason for hip and knee replacement surgery.
• Rheumatoid Arthritis (RA):
  • Autoimmune disease where cartilage and joint linings are attacked by the immune system.
  • Inflammation of the synovial membrane.
  • Formation of abnormal granulation tissue.

Stability of Joints

• Articular surfaces (shape, size, arrangement)
• Ligaments and capsule
• Muscle tone around the joint

Movement of Synovial Joints

• Gliding: flat surfaces move back-and-forth and side-to-side.
  • Angular Motions: flexion, extension, lateral flexion, abduction, adduction, circumduction, and rotation.

Clinical Check Point

• Physiotherapy for OA
• Occupational therapy for RA.

This quiz covers the essential aspects of arthrology, focusing on the study of joints and their classifications. It delves into the characteristics of synovial joints and common joint disorders such as osteoarthritis and rheumatoid arthritis. Test your knowledge on the anatomy and function of joint structures.