Introductory Anthology and the Hip Joint Flashcards
Define the term joint
A union between two or more bones
Describe the amount of movement available and structure of the different types of joints
Fibrous: Fibrous material join bone ends together
–> Suture: bones are linked by short fibres of connective tissue providing little to no movement
–> Syndesmosis: bones are linked by longer bands of connective tissue being slightly mobile
Cartilaginous: Cartilaginous tissue joins the bone together
–> Synchondrosis:
- Found at epiphyseal line where bone growth occurs
- These joints allow for bone growth
- Eventually completely ossify
- Immobile
- Sternocostal joint: some mobility
–> Symphysis:
- A disc of fibrouscartilage binds 2 bones together
- Found in the mid-line of the body
- Slightly mobile
Synovial joints: bone ends are shaped to fit one another, and covered with articular cartilage, allows the bones to slide on one another
Classify synovial joints in relation to the structure and their degrees of freedom
Give examples as well
Hinge (e.g. Elbow) - Uniaxial
Pivot (e.g. joint between Radius and Ulna) - Uniaxial
Ellipsoid (e.g. wrist)- Biaxial
Condyloid (e.g. Jaw) - Biaxial
Saddle (E.g. Thumb) - Biaxial
Ball & Socket (e.g. Shoulder) - Multi-axial
List the functions of ligaments
- Act as mechanical constraints (mechanical function)
- Prevent undesired movement
- Permit limited desired movement
- Sensory organs: proprioception
Define the classifications of ligaments and give examples
Caspular: Reinforce the capsule
Extra-capsular: Lie outside the capsule
Intra-capsular: Lie inside the capsule
What is the structure of and list the functions of articular discs
They are pads of fibrocartilage that are situated between the articular surfaces of some synovial joints
Functions to:
- Act as shock absorbers
- Aid mechanical fit between articular surfaces resurfaces
- Restrain movement
- Assist lubrication
- Permit different movement to occur in joint
Define the structure and list the functions of bursae
Function: To reduce friction as structures slide on one another
Therefore are located between layers of muscles
Where muscles and tendons overlie bony prominences
They are:
- Fluid-filled sacs around many synovial joints
- A potential rather than actual spaces
Describe the 3 principal axes of movement about synovial joints
Anteroposterior : allows for abduction/adduction and lateral flexion
Transverse: Flexion/ extension
Longitudinal: Rotational
Define and demonstrate active and passive (physiological and accessory)
Active movement: produced by muscle contraction
Examples:
Angular movements: flexion/ extension (transverse axis) and abduction/ adduction (anteroposterior axis)
Rotational movements: internal (medial/ external (lateral) rotation –> longitudinal axis
Passive movements: produced by an external force
Passive physiological: could also be produced actively
Passive accessory: cannot be produced actively
Define the terms roll, spin and slide as they apply to movements between he surfaces of synovial joints
Spin: One surface spins relative to the other surface - around a fixed central axis
Roll: One surface rolls across the other so new parts surfaces come into contact
Slide: One surface slides across the other so new parts of one surface come into contract with the same part of the other surface
Describe the features of the close packed position of synovial joints
It is the position where:
- where surfaces are minimally congruent
- the ligaments & capsule are maximally taut
Greatest joint stability is achieved for the least energy
In this position: the joint is resistant to tensile forces that tend to cause separation
Little or no joint play is possible
Will be a slightly different position for each joint
Classify the hip joint
Synovial, multiaxial ball and socket
Describe the hips articular structures
Joint capsule:
- Strong
- Thickest anteriorly and superiorly
- Attaches to labrum and surrounding bone on innominate (and to transverse ligament at the notch)
- Reflected onto neck of femur attaching to intertrochanteric line
Synovial Membrane:
- Lines internal surface of capsule and covers labrum
- Cavity communicated with eh posts major bursa
Describe the hip joint’s articular structures
Acetabular notch:
- Inferior deficiency of the acetabulum
- Transverse ligament
Acetabula Labrum
- Fibrocartilage wedge attached to rim of acetabulum
- Deepens socket and therefore increases stability
Head of femur - Convex surface
- 2/3 sphere
Covered with articular cartilage, except for small area of head (fovea capitis)
Describe the joint capsule and synovial membrane
Joint capsule:
- Strong
- Thickest anteriorly and superiorly
- Attaches to labrum and surrounding bone on innominate (and to transverse ligament at the notch)
- Reflected onto neck of femur attaching to intertrochanteric line
Synovial Membrane:
- Lines internal surface of capsule and covers labrum
- Cavity communicated with eh posts major bursa
Describe the Illiofemoral
- Capsular
- Located anteriorly triangular in shape
- Inferior bands limits extensions and external rotation
- Superior band limits extension, adduction and external rotation
- Sometimes small deficiency anteriorly covered by iliopsoas
Describe the Ischiofemoral
- Capsular
- Located posteriorly
- Least well defined
- Limits extension, abduction and internal rotation
Define the Pubofemoral
- Capsular
- Located inferior and anteriorly
- Limits abduction, extension and external rotation
Describe the transverse ligament of the acetabulum
- Completes acetabulum, breaches the acetabulum notch
Describe the Ligamentum Teres
- From transverse ligament to fovea capitis
- No strict mechanical function but may provide proprioceptive role
Describe the Acetabular Labrum
Increases the depth of acetabular articular area. It plays a role in joint stability as provides a constriction to the diameter of the acetabular articular cavity where the femoral head fits.
describe the arrangement of the following bursae around the hip:
- Greater trochanteric
- Iliopectineal
Greater trochanateric bursa:
Sits between the greater trochanter and iliotibial band
Iliopectineal bursa:
- Often referred to as the iliopsoas bursa
- Lies between the tendon of iliopsoas and the fibrous capsule of the hip
Describe the factors that confer stability to the hip joint
Articular fit: reasonable congruence
Acetabular labrum
Strong capsule
Functions of muscles - Line of pull
Bony factors:
- angle of inclination
- -> angulation of head with shaft
- -> reflects and adaptation to bipedalism
- -> increases stability by increasing contact area of the surfaces
