Joints Flashcards
Define joint, what are two types
two skeletal elements come together; synovial and solid
Synovial Joint
skeletal elements are separated by a narrow articular cavity (cavity looks larger because cartilage doesn’t attenuate X-rays as well as bone)
What are the three features of a synovial joint?
1) hyaline cartilage
2) inner synovial membrane
3) outer fibrous membrane
Outer fibrous membrane
dense connective tissue that surrounds and stabilizes the joint; can thicken to form ligaments
Inner Synovial Membrane
encloses the joint cavity at the margins of the joint surfaces at the interface b/w cartilage and bone; very vascular and produces synovial fluid which is a lubricant for the joint
Hyaline Cartilage
covers articulating surfaces of skeletal elements
What are synovial bursae?
closed sac of synovial membrane that occur b/w structures to reduce friction
Where do we find synovial bursae?
tendon/bone; tendon/joint; skin/bone
What is a tendon sheath?
a closed sac of synovial membrane that covers a tendon to reduce friction
We classify joints by ______ and _______.
Shape; movement
What are the seven shapes of synovial joints?
- plane (flat)
- hinge
- pivot
- bicondylar
- condylar (ellipsoid)
- saddle
- ball and socket
What are the three types of movement of synovial joints?
- uniaxial (UA) - moves in one direction (x, y, or z)
- biaxial (BA) - moves in two directions (xy, yz, or xz)
- multiaxial (MA) - moves in all directions
Describe and provide an example of a plane joint.
UA - sliding/gliding when a bone moves across another
i.e. acromioclavicular joint (scapula glides past clavicle when raising and rotating arm)
Describe and provide an example of a hinge joint.
UA - allows movement along 1 axis and the direction is transverse
i.e. humero-ulnar (elbow) joint (allows for flexion and extension)
Describe and provide an example of a pivot joint.
UA - allows movement along axis that is longitudinal to the shaft of the bone
i.e. atlanto-axial joint. (in neck, allows you to turn head left and right)
Describe and provide an example of a bicondylar joint.
BA - allows complete movement in 1 axis and limited movement in 2nd axis; formed by two convex condyles that articulate w/ concave or flat surfaces
i.e. knee joint
Describe and provide an example of a condylar (ellipsoid) joint.
BA - movement around 2 axes that are at right angles to each other
i.e. wrist joint (flexion, extension, abduction, adduction, limited circumduction)
Describe and provide an example of a saddle joint.
BA - movement around 2 axes that are at right angles to each other, articular surface looks like a saddle
i.e. Carpometacarpal (thumb) joint (flexion, extension, abduction, adduction, circumduction)
Describe and provide an example of a ball and socket joint.
MA - movement in all directions
i.e. hip joint (flexion, extension, abduction, adduction, circumduction, rotation)
What are three common additional features of synovial joints that are not universal to all synovial joints.
- Articular Discs (Fibrocartilage)
- Fat Pads
- Tendons
Articular Discs
(fibrocartilage) absorb compression forces, adjust to changes in contours of joint surfaces during movement, and increase range of motion
Fat Pads
can be found between inner synovial and outer fibrous membranes; moves into and out of region as joint contours change
Solid Joints
adjacent skeletal elements inked by fibrous connective tissue or cartilage
Three types of fibrous connective tissue linked solid joints?
- suture
- gomphoses
- syndesmoses
Suture (solid) joints
skull only, sutural ligament connects bone plates
Gomphoses (solid) joints
b/w teeth and adjacent bone
Syndesmoses (solid) joints
two adjacent bones linked by a ligament
List two examples of syndesmoses joints.
Ligamentum Flavum (connects vertebral laminae) and Interosseus membrane (connects radius and ulna)
What are the two types of cartilaginous solid joints?
Synchondroses and Symphyses
Synchondroses (solid) joints
two ossification centers in a developing bone remain separated by cartilage (growth plate)
Symphyses (solid) joints
two separate bones connected by cartilage, typically occurring in midline (i.e. intervertebral discs and pubic symphysis)
Osteoarthritis (ITC)
degenerative joint disease related to aging that accounts for 1/4 PCP visits; can be secondary to RA or infection; treat with weight loss, exercise, anti-inflammatory medication, or joint replacement
Biological “flow chart” of osteoarthritis progression (ITC)
decreases in water and proteoglycan in cartilage leads to increased fragility and susceptibility to mechanical disruption of the joint - ultimately cartilage wears down causing bone fissures and thickening
synovial fluid can enter these fissures creating large cysts and osteophytes (bony outgrowths) form
result: altered biomechanics forces – stress – disruption of joint
Arthoscopy (ITC)
surgical procedure in which a small telescope is inserted through a small incision to visualize a joint; other tools may be inserted through separate incisions to repair any damage; common in hip, shoulder, knee, ankle
Benefits of arthoscopy (ITC)
quick recovery time, local anesthetic or light anesthesia
Joint Replacement
surgical procedure where both sides of the joint are replaced to improve quality of life (joint destruction or degenerative joint disease is reducing QOL)
typically done for larger joints, but with tech advancements smaller joint replacements are becoming increasingly common
