Joint Mechanics Flashcards
Cartilaginous Joint
Amphiarthrosis
Two contiguous surfaces united by fibrocartilaginous disks
No cavity between the bones
Strong ligamentus support
Small amount of rocking and sliding motion
Subtypes: hyaline, fibrocartilage
Hyaline
- synchondroses
- cartilage United the bones at the unction of cartilage
- permits light bending during early life
- temporary Union in long bone growth (epiphyseal plate)
Fibrocartilage
- symphyses
- cartilage fuses into a pad of fibrocartilage that is compressible and allows some movement
- center of each pad/disc is the nucleous pulposus (cushion/shock absorber)
Synovial Joint
Diarthrosis
Most common joint
Articulating bones do not touch
Separated by a fluid-containing joint cavity
Freely mobile
Some contain fibrocartilage discs or meniscus
Articular surface covered with hyaline cartilage
Enclosed by a fibrous joint capsule creates a closed joint cavity
Synovial membrane lines the joint capsule secreting a viscous fluid nourishing and lubricating the hyaline cartilage
Types:
- plane
- hinge (ginglymus)
- saddle
- condyloid
- ball and socket (ellipsoid, condylar)
- pivot
Plane Synovial Joint
Two flat surfaces
Motion limited to minimal sliding
Ex: triquetreum-pisiform
Ginglymus Synovial Joint
Hinge
Allows for large degree of freedom of motion in one plane
Ex: elbow
Spherical Synovial Joint
Ball and socket
Round convex head that articulates with a concave surface
Allows greatest degree of motion
Modified ball and socket:
- condylar: partial flattering of both articular surfaces; limits motion; ex: metacarpal-phalangeal
- ellipsoid: head is ellipsoid; greater motion than condylar less than spheroid; ex: radiocarpal
Trochoid Synovial Joint
Composed of a ball shape that is surrounded by a circle composed of bone and ligament
Primary motion is rotation
Ex: atlas and axis
Sellar Synovial Joint
Composed of one concave and one convex bone
Allows for greater motion in all planes
Ex: thumb
Synovial Articular Discs (Meniscus)
Vascular and nerve supply at the periphery
Buffer and maintains normal joint relationship
Limit joint motion in undesirable direction
Synovial Fibrocartilaginous (Labrum)
Deepens the articular surface
Synovial Tendons
Within the capsule of the joint
Can become contiguous with fibrocartilaginous labrum
Hilton’s Law
Nerves supplying a joint also supply the muscles moving the joint and the skin covering the attachments of these muscles
Joint play, a small but precise amount of movement, which is independent of the action of voluntary muscle function is best assessed in: A. Active exam B. Passive exam C. Postmortem exam D. Practical exam
B. Passive exam
This type of joint has primarily a small amount of rocking and/or sliding motion.
A. Cartilaginous
B. Synovial
C. Fibrous
D. Colorado Gold
A. Cartilaginous
Common elements of a synovial joint include all of the following except:
A. Fibrous capsule B. Hyaline cartilage C. Ligamentous reinforcement D. Synchondrosis E. Synovial membrane
D. Synchondrosis
A synovial joint that acts as a hinge is known as this type of joint:
A. Plane B. Ginglymus C. Saddle D. Condyloid E. Ellipsoid
B. Ginglymus
The nerve endings within a joint are primarily found within this part of the joint:
A. Hyaline Cartilage B. Fibrocartilage C. Articular Capsule D. Vascular Anastomosis E. Tendons
C. Articular capsule
Wolff’s Law
Bone is increased where needed and reabsorbed where it is not
Increased density/hypertrophy related to increased stresses
Decreased - condition of disuse,aging
Can lead to altered stress/strain properties of the bone
Remodeling and Adaptation: Cartilage
Trauma or abnormal wear leads to structural disruption of matrix
Loses elasticity therefore increases stiffness
Limited capacity to regenerate or repair
With repeated high stresses can lead to development or degenerative joint disease
Remodeling and Adaptation: Ligaments and Tendons
Become stronger and stiffer with increased stress
Number and quality of collagen cross-links increase
Become weaker and less stiff with a reduction of stress
Loss of collagen, loser deformation to fail: immobilization, aging
Inflammatory Arthritis
Rheumatoid Arthritis
Most common inflammatory arthritis
75% women between 30-60 yo
Joint swelling
Immune system mistakenly attacks the synovial and cartilage of the joint
Cartilage wears away, cushioning fluid (synovium) becomes inflamed => chemicals to be released that damage the cartilage and bone of affected joint
Osteoarthritis
Most common type (16 million in the US)
Usually middle-aged and older people
Joint disease that gets worse over time
Does not cause swelling in joints (not inflammatory)
Cartilage starts to erode, allows bones to grid or rub together => pain
Traumatic Arthritis
People who have experienced an injury or fracture
Leads to a conduction called avascular necrosis: blood supply to bone is cut off
Lack of blood supply causes surrounding cartilage to deteriorate and bones grind or rub together => pain
Joint Degeneration: Fibrillation
Early degenerative change of articular cartilage due to loss of proteoglycans
Unmasks collagen fibers and increases water content in chondrocytes
Affected cartilage becomes dull with yellowish discoloration
GROUND CLASS APPEARANCE
Joint Degeneration: Ebrunation
Complete loss (ulceration) of articular cartilage
Thickening of subchondral bone - osteosclerosis
Permanent lesion
Pain on weight bearing
IVORY LIKE APPEARANCE
Joint Degeneration: Joint Mice
Osteochondromatosis
Fragments of cartilage and/or bone floating free in synovial fluid
Pieces of degenerating cartilage detach from subchondral bone
Catching and locking of joint
Commonly seen in degenerative joint diseases: osteochondrosis dissecans (OCD)
Plain Films
X-ray
Evaluates structure, relationship
CT Scan
Evaluates osseous structures, blood
MRI
Evaluates soft tissue best
Contrast
Interarticular - CT scan
- joint: look for what’s not there
Intravenous - MRI
- blood flow
Blood Work
Biomarkers
- normal function
Inflammation markers
- abnormal function
Immunological studies
- abnormal function
- autoimmune
Electromyography
Innervation function
Vascular Studies
Structural integrity
42 year old female presents to the office complaining that, on occasion, her left knee locks and catches. She has noticed particularly while playing golf. After a minute or less it stops and she is able to have a full range of motion again.
PE: negative findings:
- McMurray
- Valgus/Varus Stress
- Anterior/Posterior Drawer
- Pivot Shift/Lachmans
- No swelling or joint fluid on observation or Palpation
What test would you want to order next?
A. Blood work B. X-ray C. EMG D. Vascular study E. None of the above
B. X-ray
42 year old female presents to the office complaining that, on occasion, her left knee locks and catches. She has noticed particularly while playing golf. After a minute or less it stops and she is able to have a full range of motion again.
PE: negative findings:
- McMurray
- Valgus/Varus Stress
- Anterior/Posterior Drawer
- Pivot Shift/Lachmans
- No swelling or joint fluid on observation or palpation
What intervention would you do next?
A. OMT B. Physical Therapy C. Injection D. Surgery E. Non-steroidal
D. Surgery
61 year old male presents to the office with 16 months of low back pain causing him to limp which is getting worse. Pain at it's worse 9/10, Tylenol used to help but not anymore. Increases as the day goes on, keeps him from doing his activities of daily living. Has been to Chiro, his back pops, pain better for an hour or so then all comes back. PE: Flattening of lumbar spine - TART changes throughout - Decreased ROM Lumbar Spine - Positive log roll - Short leg on the right - neuro vascular exam normal
What test would you want to order?
A. Blood work B. X-Ray C. EMG D. Vascular study E. None of the above
B. X-Ray
61 year old male presents to the office with 16 months of low back pain causing him to limp which is getting worse. Pain at it's worse 9/10, Tylenol used to help but not anymore. Increases as the day goes on, keeps him from doing his activities of daily living. Has been to Chiro, his back pops, pain better for an hour or so then all comes back. PE: Flattening of lumbar spine - TART changes throughout - Decreased ROM Lumbar Spine - Positive log roll - Short leg on the right - neuro vascular exam normal
What inner action would you do next?
A. OMT B. Physical Therapy C. Injection D. Surgery E. Non-steroidal
D. Surgery
24 year old male presents to clinic with CC low back pain. Notices with lifting or running. Plays pro-indoor soccer works on loading dock in off season. Pain between a 2-6/10, constant, radiates into groin, notices worse when extends leg or turns quickly. Has not taken anything for the pain. PE: normal curvature of lumbar spine - TART changes on the right L5-S1 area - Decreased flexion of Lumbar Spine - Negative Log Roll - Short leg on the right - neuro vascular exam normal
What test would you want to order next?
A. Blood work B. X-Ray C. EMG D. Vascular study E. None of the above
B. X-Ray
24 year old male presents to clinic with CC low back pain. Notices with lifting or running. Plays pro-indoor soccer works on loading dock in off season. Pain between a 2-6/10, constant, radiates into groin, notices worse when extends leg or turns quickly. Has not taken anything for the pain. PE: normal curvature of lumbar spine - TART changes on the right L5-S1 area - Decreased flexion of Lumbar Spine - Negative Log Roll - Short leg on the right - neuro vascular exam normal
What intervention would you do next?
A. OMT B. Physical Therapy C. Injection D. Surgery E. Non-steroidal
A. OMT
24 year old male presents to clinic with CC low back pain. Notices with lifting or running. Plays pro-indoor soccer works on loading dock in off season. Pain between a 2-6/10, constant, radiates into groin, notices worse when extends leg or turns quickly. Has not taken anything for the pain. PE: normal curvature of lumbar spine - TART changes on the right L5-S1 area - Decreased flexion of Lumbar Spine - Negative Log Roll - Short leg on the right - neuro vascular exam normal
Same athlete gets taken down from behind during a match. Has immediate pain in his right ankle and is unable to bear weight without significant pain.
PE: effusion of the ankle joint
- TTP on anterior Tamar dome
- Pain with passive flexion and extension
- Pain with tilt, anterior drawer, and squeeze tests
What test would you want to order next?
A. Blood work B. X-Ray C. EMG D. Vascular study E. None of the above
B. X-Ray
24 year old male presents to clinic with CC low back pain. Notices with lifting or running. Plays pro-indoor soccer works on loading dock in off season. Pain between a 2-6/10, constant, radiates into groin, notices worse when extends leg or turns quickly. Has not taken anything for the pain. PE: normal curvature of lumbar spine - TART changes on the right L5-S1 area - Decreased flexion of Lumbar Spine - Negative Log Roll - Short leg on the right - neuro vascular exam normal
Same athlete gets taken down from behind during a match. Has immediate pain in his right ankle and is unable to bear weight without significant pain.
PE: effusion of the ankle joint
- TTP on anterior Tamar dome
- Pain with passive flexion and extension
- Pain with tilt, anterior drawer, and squeeze tests
What intervention would you do next?
A. OMT B. Physical Therapy C. Injection D. Surgery E. Non-steroidal
D. Surgery
A 43 year old male has recurrent anterior shoulder pain and reports he dislocated that same shoulder several times while playing collegiate soccer. An MRI confirms a suspicion that he has torn his labral cartilage.
What type of synovial joint has been injured?
A. Condyloid B. Ginglymus C. Plane D. Saddle E. Spheroidal
E. Spheroidal
57 year old UPS driver presents to the office complaining of medial knee pain bilaterally. It has progressively been getting worse over the last two years. He is in the office because recently his left knee has been locking in flexion. You order a plain film x-Ray of the knee and observe medial joint space narrowing, some osteophylic lipping of the joint lines, what appears to be a couple of loose bodies, and a hard-polished appearance of the end plate of the medial femur and tibia. You would diagnosis this patient with Osteoarthritis and know that locking of the joint to be due to:
A. Eburnation B. Gout C. Osteochromatosis D. Osteoporosis E. Osteophytes
C. Osteophromatosis
Fibrous Joint
Synarthrosis
Connected by dense fibrous tissue - fills the space
Motion greatly limited
Suture edges types: squamous - overlapping edges; serrated - interlocking edges
Examples:
- cranial articulations
- sydesmosis: joint united by a ligament ours fibrous sheet
- gomphosis: a conical process fitting into a socket in an immovable joint
