Anatomy Booklet Flashcards
What is clinically significant about C7?
- easily palpable landmark identified for counting vertebra
- prominent spinous process
What is clinically significant about T7?
- xiphoid
- tip of scapula
What is clinically significant about L1?
- conus medullaris (end of spinal cord)
What is clinically significant about L3?
- aorta bifurcation
What is clinically significant about L4?
- iliac crest
What is a ‘hangman’s fracture’?
- hyperextension of the head on the neck
- severe = C2 body displaced anteriorly with respect to C3 = injures spinal cord/brainstem
What is the difference between trabecular and cortical bone?
- also cancellous vs. compact bone
- spongy vs. tough
- trabecular is less dense, weaker, more flexible, greater SA:V
How does osteoporosis occur with age?
- vertebral bodies have high proportion of trabecular bone to compact bone
- net loss and remaining bone deteriorates in quality
- skeletal muscle loss = less force and support adding to loss of bone
- late stage = vertebral bodies especially in thoracic region collapse and get excessive kyphosis
What areas does osteoporosis most commonly affect?
- neck of femur
- vertebral bodies
- metacarpal
- radius
What is the significance of striation?
- vertebral bodies moderate osteoporosis early on via vertical striation
- later stages more spongy trabecular bone lost so striated pattern lost
How do the vertebra change during ageing?
- middle aged = decrease in bone density and strength so IV disc more convex and articular surface bows inward
- loss of height
- loss of disc space
- therefore increase in compressive forces at periphery of bodies
- osteophytes develop
What is lumbar spinal stenosis?
- narrowing of vertebral foramen
- caused by genetics or age related
- spinal nerves exiting lumbar region increase in size but intervertebral foramina decrease in size
- may compress 1 or more of spinal nerve roots
How may lumbar spinal stenosis be surgically treated?
decompressive laminectomy
What is spinal enthesopathy?
- paraspinal ligaments undergo degeneration then ossify
- does not involve sacroiliac joint
- left side of spine spared/less involved = may have to do with pulsating aorta
What 6 elements do you check in a clinical exam of the spine?
- gait (wide based, leaning forwards)
- alignment (dislocation/scoliosis/kyphosis/lordosis)
- posture (same as above, sapsm, loss of lordosis)
- skin (hairy tufts, soft masses, port-wine spots, growths, café-au-lait spots)
- palpate bony structures (focal tenderness = fracture)
- palpate soft tissues
What would tenderness be a sign of?
- osteoarthritis/dislocation
- if diffuse tenderness = sprain/muscle sprain
What is the function of the upper limb?
- movement
- not very stable so prone to dislocations
What is important about the sternoclavicular joint?
Only joint holding upper limb to the axial skeleton
What is one of the most commonest bones to fracture?
- clavicle
- direct or indirect force
What happens post clavicle fracture?
- SCM pulls medial fragment upwards
- trapezius unable to hold lateral fragment upwards against arm weight and gravity so shoulder drops
What is the commonest joint to dislocate?
- glenohumeral joint
- between glenoid fossa of the scapula and head of humerus
- mostly anterior dislocations
- classic feature is loss of rounded shoulder profile as arm is dragged inferiorly
- in young/athletic
- glenoid labrum tears
- rotator cuff tears if over 40 years
What nerve is at risk in a glenohumeral dislocation? What are the signs of damage?
- axillary
- close to inferior part of joint capsule
- deltoid muscle paralysis
- loss of sensation in skin area covering central deltoid (regimental patch)
What commonly causes rotator cuff injuries?
- repetitive use of the upper limb above horizontal
What is the mechanism of a rotator cuff injury?
- tendons are relatively avascular so repetitive injuries required to accumulate into a complete tear
- fibrocollagenous scar left = weaker than dense regular arrangement of original tendon
Which rotator cuff tendon is most commonly damaged?
- supraspinatus
- passes under acromion of scapula where it can be impinged
What are the different types of humeral fractures?
- most are proximal around surgical neck = common in elderly/osteoporosis
- middle aged and older = avulsion fractures of greater tubercle, due to falls on acromion
- mid shaft fractures = result of direct force
- supracondylar/intercondylar fractures = falls on flexed elbow
- children = epiphyseal growth plates open so fracture dislocation of proximal humerus may occur as rotator cuff stronger than plate
What is an avulsion fracture?
Injury to a bone where a tendon/ligament attaches to it
What joints makes up the elbow?
- humero-ulnar
- humero-radial
- proximal radio-ulnar
How does a posterior dislocation of the elbow joint occur?
- hyperextension or blow driving ulna posteriorly/laterally
- distal humerus driven through weaker joint capusula anteriorly
- ulnar collateral ligament torn
- associated fractur of radius head coronoid process or olecranon process of ulna
Define subluxation
Partial dislocation
How can subluxation of the radial head occur?
- in infants
- small size of radial head compared to annular ligament into which it fits
What is a Colles’ fracture?
- distal radius fracture
- most common fracture under 45 years
- falls on outstretched hand which is pronated and extended
- dinner fork deformity presentation
What other common injury is caused by the same mechanism as the Colles’ fracture?
- fracture of the scaphoid
- most common carpal fracture
- blood supply to scaphoid compromised = avascular necrosis
- ## retrograde blood supply to proximal pole which may die whilst nutrient arteries enter distal portion of bone so heals
What is a Smith’s fracture?
- distal radius
- falling onto flexed wrists
- or direct blow to dorsal forearm
- less common than Colles’
- garden spade deformity presentation
What is the function of the lower limb?
- stability
What type of joint is the pubic symphysis?
- fibrocartilage joint
What type of joint is the sacroiliac joint?
Synovial joints
How may pelvic avulsion fractures occur?
- during sports where there is sudden acceleration/deceleration
- hamstrings attach to ischial tuberosity of pelvis
which can be torn away at apophyses
What are apophyses?
Bony projections that lack secondary ossification centres
What are the features of femur fractures?
- age as neck of femur has high proportion of trabecular bone = osteoporosis
- neck of femur is narrowest and weakest part and at a angle to line of weight bearing (gravity pull)
- usually intracapsular fracture
- get shortening of limb and usually externally rotated
What is the blood supply to the head and neck of the femur?
Medial circumflex artery
What is the major clinical problem femoral fractures?
- retinacular arteries arising from medial circumflex arteries are often torn which supply blood to head and neck of femur
- sometimes only blood supply is via artery in ligament of the head = avascular necrosis of head of the femur
How may dislocation of the femoral head occur?
- uncommon as hip joint stable
- road traffic accidents if sat down and flexed knee hits dashboard forcing femoral head posteriorly
- joint capsule ruptures out of acetabulum
- limb shortened
- medially rotated
- associated with fractures to femoral head/neck/acetabulum
How do femoral shaft fractures occur?
- require high energy trauma
- associated with other injuries
- source of blood loss and release of fat emboli
- traction for re-aligning bone pieces
- large thigh muscles go into spasm and contract displacing fragments
How can the patella be fractured?
- direct forces = falls
- indirect = embedded in quadriceps tendon so pull of muscles can cause fracture or fragment displacement
What is a bipartite patella?
Unfused superolateral corner
How can a tibia be fractured?
- indirect trauma to tibial shaft when bone turns with foot during a fall
- severe torsion = diagonal fracture of tibial shaft with fibula fracture
How may fractures of the malleoli occur?
- very common at all ages
- 1 malleoli involved = stable
- bimalleoli = unstable and added complication is fracture dislocation to talo-crural joint (ankle)
- lateral more common than medial
- excessive inversion of foot so ligaments tear on lateral side
What is plantar fasciitis?
- Inflammation of the plantar fascia
- result of overuse
- plantar surface of foot and heel pain
- irritated by calcaneal spur at point of attachment
What is the function of the upper limb?
- movement
- not very stable so prone to dislocations
What is important about the sternoclavicular joint?
Only joint holding upper limb to the axial skeleton
What is one of the most commonest bones to fracture?
- clavicle
- direct or indirect force
What happens post clavicle fracture?
- SCM pulls medial fragment upwards
- trapezius unable to hold lateral fragment upwards against arm weight and gravity so shoulder drops
What is the commonest joint to dislocate?
- glenohumeral joint
- between glenoid fossa of the scapula and head of humerus
- mostly anterior dislocations
- classic feature is loss of rounded shoulder profile as arm is dragged inferiorly
- in young/athletic
- glenoid labrum tears
- rotator cuff tears if over 40 years
What nerve is at risk in a glenohumeral dislocation? What are the signs of damage?
- axillary
- close to inferior part of joint capsule
- deltoid muscle paralysis
- loss of sensation in skin area covering central deltoid (regimental patch)
What commonly causes rotator cuff injuries?
- repetitive use of the upper limb above horizontal
What is the mechanism of a rotator cuff injury?
- tendons are relatively avascular so repetitive injuries required to accumulate into a complete tear
- fibrocollagenous scar left = weaker than dense regular arrangement of original tendon
Which rotator cuff tendon is most commonly damaged?
- supraspinatus
- passes under acromion of scapula where it can be impinged
What are the different types of humeral fractures?
- most are proximal around surgical neck = common in elderly/osteoporosis
- middle aged and older = avulsion fractures of greater tubercle, due to falls on acromion
- mid shaft fractures = result of direct force
- supracondylar/intercondylar fractures = falls on flexed elbow
- children = epiphyseal growth plates open so fracture dislocation of proximal humerus may occur as rotator cuff stronger than plate
What is an avulsion fracture?
Injury to a bone where a tendon/ligament attaches to it
What joints makes up the elbow?
- humero-ulnar
- humero-radial
- proximal radio-ulnar
How does a posterior dislocation of the elbow joint occur?
- hyperextension or blow driving ulna posteriorly/laterally
- distal humerus driven through weaker joint capusula anteriorly
- ulnar collateral ligament torn
- associated fractur of radius head coronoid process or olecranon process of ulna
Define subluxation
Partial dislocation
How can subluxation of the radial head occur?
- in infants
- small size of radial head compared to annular ligament into which it fits
What is a Colles’ fracture?
- distal radius fracture
- most common fracture under 45 years
- falls on outstretched hand which is pronated and extended
- dinner fork deformity presentation
What other common injury is caused by the same mechanism as the Colles’ fracture?
- fracture of the scaphoid
- most common carpal fracture
- blood supply to scaphoid compromised = avascular necrosis
- ## retrograde blood supply to proximal pole which may die whilst nutrient arteries enter distal portion of bone so heals
What is a Smith’s fracture?
- distal radius
- falling onto flexed wrists
- or direct blow to dorsal forearm
- less common than Colles’
- garden spade deformity presentation
What is the function of the lower limb?
- stability
What type of joint is the pubic symphysis?
- fibrocartilage joint
What type of joint is the sacroiliac joint?
Synovial joints
How may pelvic avulsion fractures occur?
- during sports where there is sudden acceleration/deceleration
- hamstrings attach to ischial tuberosity of pelvis
which can be torn away at apophyses
What are apophyses?
Bony projections that lack secondary ossification centres
What are the features of femur fractures?
- age as neck of femur has high proportion of trabecular bone = osteoporosis
- neck of femur is narrowest and weakest part and at a angle to line of weight bearing (gravity pull)
- usually intracapsular fracture
- get shortening of limb and usually externally rotated
What is the blood supply to the head and neck of the femur?
Medial circumflex artery
What is the major clinical problem femoral fractures?
- retinacular arteries arising from medial circumflex arteries are often torn which supply blood to head and neck of femur
- sometimes only blood supply is via artery in ligament of the head = avascular necrosis of head of the femur
How may dislocation of the femoral head occur?
- uncommon as hip joint stable
- road traffic accidents if sat down and flexed knee hits dashboard forcing femoral head posteriorly
- joint capsule ruptures out of acetabulum
- limb shortened
- medially rotated
- associated with fractures to femoral head/neck/acetabulum
How do femoral shaft fractures occur?
- require high energy trauma
- associated with other injuries
- source of blood loss and release of fat emboli
- traction for re-aligning bone pieces
- large thigh muscles go into spasm and contract displacing fragments
How can the patella be fractured?
- direct forces = falls
- indirect = embedded in quadriceps tendon so pull of muscles can cause fracture or fragment displacement
What is a bipartite patella?
Unfused superolateral corner
How can a tibia be fractured?
- indirect trauma to tibial shaft when bone turns with foot during a fall
- severe torsion = diagonal fracture of tibial shaft with fibula fracture
How may fractures of the malleoli occur?
- very common at all ages
- 1 malleoli involved = stable
- bimalleoli = unstable and added complication is fracture dislocation to talo-crural joint (ankle)
- lateral more common than medial
- excessive inversion of foot so ligaments tear on lateral side
What is plantar fasciitis?
- Inflammation of the plantar fascia
- result of overuse
- plantar surface of foot and heel pain
- irritated by calcaneal spur at point of attachment
