Joint Structure Flashcards
Name the 2 major classifications of joints
- diarthrosis (synovial jt)
- synarthrosis
Which classification of joints is mobile?
diarthrosis
Synarthroses that have some motion are called ____
amphiarthroses
Name the subclassifications of diarthroses by type of movement
- Uniaxial
- Biaxial
- Polyaxial (3 axes)
- Plane (flat jt)
What are some examples of uniaxial joints?
- ulnohumeral jt
- proximal & distal radioulnar jts
What is an example of a biaxial joint?
radiocarpal jt
A hinge joint is an example of what type of diarthrodial joint?
uniaxial
A gliding joint is an example of what type of diarthrodial joint?
uniaxial (1 axis)
A joint that does flexion, extension, abduction and adduction is an example of what type of diarthrodial joint?
biaxial (2 axes)
What are some examples of polyaxial joints?
- shoulder
- hip
What are some examples of plane joints?
- zyapophyseal
- patellofemoral
- carpals/tarsals
What type of diarthrodial joint has the most motion and least stability relative to other types of joints?
polyaxial (3 axes)
What are the subclassifications of synarthrodial joints?
- symphysis
- suture
- synchondrosis
- syndesmosis
- synostosis
Describe the structure of a symphysis
fibrocartilage & ligaments
Describe the structure of a suture
interdigitating bones with ligamentous connections
Describe the structure of a synchondrosis
structures with cartilage ends, but no synovium
Describe the structure of a syndesmosis
fibrous connections between bones without cartilage
Describe the structure of a synostosis
normal variant or pathological fusion of bones
Name an example of a symphysis
- pubic symphysis
- IVDs
Name an example of a suture
skull
Name an example of a synchondrosis
- manubriosternal
- costochondral
Name an example of a syndesmosis
interosseous membrane at:
- tibiofibular jt
- radioulnar jt
Name an example of a normal synostosis
5th toe synphalangism (DIP jt fusion)
Name an example of a pathological synostosis
SI ankylosis in ankylosing spondylitis
What type of synarthrodial joint is technically an amphiarthrosis?
symphysis (should allow limited motion)
What type of synarthrodial joint would not be affected by rheumatoid arthritis?
synchondrosis
(no synovium)
A high ankle sprain affects what type of joint?
syndesmosis
Inflammation of the spine resulting in fusion of joints is an example of what type of joint?
pathological synostosis
(ankylosing spondylitis)
A closed physis is called a ____
physeal scar
What usually covers the articular ends of synovial joints?
hyaline cartilage
What is the term for the ligamentous sleeve that holds bones together?
joint capsule
What is the bare area of a joint?
space between where cartilage ends and synovium begins (bone only)
During development, if the notochord does not separate into the anterior spinal elements, what type of joint is formed?
synostosis
(congenital fusion)
What is ankylosing spondylitis?
inflammation of the spine results in fusion
The action of pronation & supination is done by what type of joint?
uniaxial diarthrodial
What is the function of facet joints and what type of joint are they?
- limit motion in certain planes
- plane (flat) joint
What type of joint are the medial and lateral facets of the patellofemoral joint?
plane (flat) joint
What type of synarthrodial joint allows the most amount of motion?
symphysis (technically an amphiarthrosis)
Which joint would not be affected by rheumatoid arthritis?
A) ulnohumeral
B) tibiofibular
C) manubriosternal
D) pubic symphysis
manubriosternal (synchondrosis)
What is a “trauma case”?
a soft tissue injury that happens to have an associated fracture
(more concerned about damaged soft tissues than broken bones)
What type of joint is of particular concern in trauma cases?
syndesmosis
(eg. high ankle sprain, monteggia Fx)
What is a Monteggia fracture and what type of joint does it concern?
fracture of the ulna with dislocation of radial head from proximal radioulnar joint (damages interosseous membrane - syndesmosis)
The articular end of a bone is called the ____
epiphysis
Where does the synovium end?
Where joint capsule meets bone
What can happen to the bare area of a joint with Rheumatoid arthritis?
- rheumatoid arth. = inflammation of synovium
- inflamed synovium pressing against bare area rapidly erodes bone, causing marginal erosion
What part of the bone has the richest vascular beds?
metaphysis (most metabolically active)
Where does the epiphysis get its blood supply from?
vascular bed from metaphysis
What creates nutrition for articular cartilage of a joint?
vascular bed of epiphysis creates nutrition via diffusion
(no BVs directly feed articular cartilage)
