ch 9 part b

Articulations (Joints) - Chapter 9 Part B

Overview of Synovial Joints

  • Synovial joints: Freely movable joints

  • Focus on selected synovial joints in this section.

Temporomandibular Joint (TMJ)

  • Definition: Jaw joint where the mandible connects to the temporal bone.

  • Common Condition: TMJ disorder.

    • Symptoms:

      • Facial pain, often from teeth clenching.

      • Clenching often occurs during sleep.

    • Considerations for Patients:

      • Assess for:

        • Anatomical/physiological issues.

        • Correct fit of teeth.

        • Length of jaw.

      • May need referrals to:

        • Dentist or orthodontist for dental issues.

        • Psychologist or counselor for stress-related clenching.

Elbow Joint

  • Description: Complex joint involving three bones, functioning in a single plane.

    • Type: Uniaxial joint, provides strong support.

  • Injury Risks:

    • Subluxation: Occurs from swinging children by their arms, leading to dislocation of the radius.

    • Tennis Elbow (Lateral Epicondylitis):

      • Caused by twisting action during activities like swinging a racket, leading to elbow pain.

Knee Joint

  • Complexity: Largest joint in the body involving four bones:

    • Upper femur, lower tibia, fibula, and patella (kneecap).

    • Ligaments: Numerous ligaments stabilize the knee, with cruciate ligaments limiting movement.

  • Injury Risks:

    • Unhappy Triad: Sustained from lateral impacts to the knee, involving:

      1. Torn tibial collateral ligament.

      2. Torn medial meniscus.

      3. Torn anterior cruciate ligament (ACL).

  • Healing Considerations: Cartilage and ligament repair is slow; knee replacements are common for severe cases.

Ankle Joint (Talocrural Joint)

  • Importance: Supports much of the body's weight; prone to injuries.

  • Injury Risks:

    • Ankle Sprains: Caused primarily by overinversion (foot turning inward).

    • Pott's Fracture: Occurs at distal ends of tibia and fibula, typically from over eversion of the foot.

  • Movement Terms:

    • Dorsiflexion: Digging heels in.

    • Plantarflexion: Planting toes.

Foot Structure and Health

  • Foot Arches: Act as shock absorbers, crucial for mobility.

    • Concern: Flat footedness can result from obesity and overstretching of ligaments.

  • Military Service Restriction: Flat-footed individuals may be disqualified from serving.

Joint Disorders: Arthritis

  • General Definition: Pain in joints; can be classified by causes:

    1. Degenerative: Joints wear out (e.g., osteoarthritis).

    2. Inflammatory: Immune system attacks joints (e.g., rheumatoid arthritis).

    3. Metabolic: Build-up of wastes leading to joint pain (e.g., gout).

  • Specific Types:

    1. Osteoarthritis: Wear and tear leading to cartilage degeneration, producing pain as bones grind together.

    2. Rheumatoid Arthritis: Autoimmune disorder where the immune system damages articular cartilage, can lead to joint fusion (ankylosis) and disfigurement.

    3. Gouty Arthritis: Metabolic disease resulting in uric acid crystal build-up in joints (especially the big toe), linked to diet and genetics.

Treatment Options

  • Arthritis treatments vary; mechanical joint replacements have become common for damaged joints, especially knees and hips.