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    Related Topics

    From Musculoskeletal System

    Symphyses
    Cartilaginous joints where bones are connected by fibrocartilage.
    Iliolumbar Ligament
    Ligament connecting the ilium and lumbar vertebrae.
    Patellar Tendon
    Tendon connecting the patella to the tibia.
    Quadriceps
    Rectus Femoris, Vastus Medialis, Vastus Lateralis, Vastus Intermedius.
    Medial Collateral Ligament (MCL)
    Knee ligament that stabilizes the inner knee.
    Wormian Bones
    Sutural bones in the skull.
    Rotator Cuff Tendons
    Tendons of the rotator cuff muscles.
    Anterior Longitudinal Ligament
    Spinal ligament running along the front of the vertebral column.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Obliques (External and Internal)
    Muscles responsible for torso rotation.
    Glenohumeral Ligaments
    Shoulder ligaments that stabilize the shoulder joint.
    Syndesmoses
    Fibrous joints where bones are connected by ligaments.
    Zygomaticus
    Muscle that raises the corners of the mouth.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Phalanges (14 bones)
    14 bones forming the toes.
    Gomphoses
    Fibrous joints where a peg fits into a socket (e.g., teeth in jaw).
    Acetabulum
    The acetabulum is the pelvic socket that connects with the femoral head to form the hip joint, vital for stability, movement, and weight-bearing.
    Thoracic Cage
    Ribs and sternum forming the protective cage for the heart and lungs.
    Frontal Bone
    Bone forming the forehead and upper part of the orbits.
    Humerus
    Upper arm bone connecting the shoulder to the elbow.
    Trapezius
    Muscle responsible for moving, rotating, and stabilizing the scapula.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Pelvic Floor Muscles
    Muscles that support pelvic organs.
    Saddle Joints
    e.g., thumb joint

    Ellipsoidal (Condyloid) Joints

    Reviewed by our medical team

    e.g., wrist

    1. Overview

    An ellipsoidal joint, also known as a condyloid joint, is a type of synovial joint that permits movement in two planes: flexion–extension and abduction–adduction. These biaxial joints have an oval-shaped condyle of one bone fitting into the elliptical cavity of another, allowing angular but not rotational movement. Ellipsoidal joints are essential for precise, controlled motion and are found in areas requiring coordinated mobility and stability.

    2. Location

    Ellipsoidal joints are present in several key areas of the body:

    • Wrist joint (radiocarpal joint): Between the distal radius and the scaphoid and lunate carpal bones.

    • Metacarpophalangeal joints (MCPs): Between the heads of metacarpal bones and bases of proximal phalanges in the fingers (knuckle joints).

    • Atlanto-occipital joint: Between the occipital condyles of the skull and the superior facets of the atlas (C1 vertebra).

    • Metatarsophalangeal joints (MTPs): Similar joints in the toes.

    3. Structure

    Ellipsoidal joints are structured for complex movement within a confined range:

    • Articular surfaces: One surface is an oval convex condyle, and the other is a reciprocally shaped concave surface.

    • Joint capsule: Encloses the joint and is lined by a synovial membrane that secretes synovial fluid.

    • Synovial fluid: Lubricates the joint, reduces friction, and nourishes articular cartilage.

    • Ligaments: Surround and stabilize the joint, preventing excessive or abnormal movement.

    • Articular cartilage: Covers the joint surfaces, allowing smooth, low-friction interaction between bones.

    4. Function

    Ellipsoidal joints allow a range of controlled, angular motions:

    • Flexion and extension: Movement in the sagittal plane, such as bending and straightening fingers.

    • Abduction and adduction: Movement in the coronal plane, such as spreading fingers apart or bringing them together.

    • Circumduction: A circular, conical motion combining flexion, extension, abduction, and adduction (but no axial rotation).

    5. Physiological role(s)

    Ellipsoidal joints play crucial roles in fine and gross motor function:

    • Manual dexterity: MCP joints are key to grasping, pinching, and manipulating objects with precision.

    • Postural alignment: Atlanto-occipital joint helps support head posture and balance.

    • Locomotion support: MTP joints contribute to propulsion and toe-off during walking and running.

    • Articulation balance: These joints enable complex joint interplay without compromising stability.

    6. Clinical Significance

    Several conditions can affect ellipsoidal joints and impair their function:

    • Osteoarthritis:

      • Degeneration of articular cartilage in MCP or wrist joints causes stiffness, pain, and loss of function.

    • Rheumatoid arthritis:

      • Commonly affects MCP joints with joint swelling, deformity (e.g., ulnar drift), and inflammation.

    • Atlanto-occipital dislocation:

      • A rare but life-threatening injury where the skull becomes dislodged from the spine, often due to trauma.

    • Joint contracture or stiffness:

      • Prolonged immobility or scarring may limit movement at ellipsoidal joints, particularly in the fingers.

    • Joint injections or aspiration:

      • Inflamed or swollen ellipsoidal joints, especially the wrist, may require corticosteroid injections or fluid removal for relief.

    Did you know? Bones become stronger when stressed by exercise.