Bones & Joints Flashcards
0
Q
What are some of the different features of bones? Give an example of each.
A
- FOSSA = hollow or depressed area e.g. infraspinous fossa of scapula
- CONDYLE = bony projection on the end of a long bone e.g. lateral and medial femoral condyles
- EPICONDYLE = smaller bony projection superior or adjacent to a condyle e.g. lateral and medial epicondyles of the humerus
- FORAMEN = passage through a bone e.g. obturator foramen of pelvis
- TUBEROSITY = large rounded elevation to which muscles attach e.g. ischial tuberosity
- TUBERCLE = smaller elevation e.g. greater tubercle of humerus
- SPINOUS PROCESS = projecting spine-like part e.g. of vertebrae, of spine of scapula
- TROCHANTER = large blunt elevation (of femur)
- FACET = flattened surface for joint/muscle attachment e.g. superior costal facet on body of vertebrae
- CREST = ridge of bone e.g. iliac crest
- SINUS = hollow space e.g. sinuses of facial bones
- MEATUS = tunnel or canal e.g. auditory meatus
- FISSURE = cleft or narrow slit e.g. supraorbital fissure
- NOTCH = indentation at edge of bone e.g. greater sciatic notch
1
Q
What are some of the different types of bone? Give an example for each.
A
- LONG: tubular (longer than wide) e.g. humerus, tibia, ulna, metacarpals
- SHORT: cuboidal (long as wide) e.g. tarsus, carpus, calcaneus
- FLAT: usually protective e.g. skull bones, ribs, sternum, scapulae
- IRREGULAR: various shapes e.g. facial bones, mandible, vertebrae, sacrum, sphenoid, carpal bones
- SESAMOID: short or irregular bones embedded in a tendon e.g. patella, pisiform
2
Q
What is the definition of a joint? What are the different types? Give an example of each.
A
JOINT = articulation between two or more bones
Fibrous:
- synarthrosis: fibrous tissue between articulating bones e.g. sutures of cranium
- syndesmosis: bones held together by fibrous tissue e.g. interosseous membrane between long bones
Cartilaginous:
- primary (synchondrosis): hyaline cartilage e.g. epiphyseal plate
- secondary (symphysis): fixed fibrocartilaginous fusion e.g. intervertebral discs
Synovial (diarthrosis): articular capsule (synovium) + synovial fluid (secreted by synovial membrane) + hyaline cartilage + fibrous capsule e.g. knee
3
Q
What is the difference between rheumatoid and osteoarthritis? What area is affected in each?
A
RHEUMATOID ARTHRITIS = damaged fibrous capsule of synovial joint
OSTEOARTHRITIS = damaged hyaline cartilage of synovial joint
4
Q
What factors affect the stability of joints?
A
- shape, size, & arrangement of the articular surfaces
e. g. change in shape is a common fracture site - ligaments
e. g. can be damaged by excessive stretching, tearing, or rupture - tone of muscle around the joint (decreases with age)
5
Q
Why is the glenohumeral joint inherently unstable? What factors increase the stability of this joint?
A
Disproportion between surface area of glenoid cavity and head of humerus
- glenoid labrum (fibrocartilaginous rim) deepens glenoid fossa; increasing stability
- rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis)
- associated muscles (deltoid, long head of biceps, long head of triceps = resist downwards dislocation)
- capsule (biceps tendon lies within joint cavity with synovium reflected over it)
- ligaments (intra-capsular and extra-capsular)
6
Q
Describe the intra-capsular and extra-capsular ligaments of the glenohumeral joint.
A
INTRA-CAPSULAR: 3 fibrous bands extending between glenoid labrum and humerus which reinforces the capsule anteriorly - superior - middle - inferior
EXTRA-CAPSULAR:
- coracoacromial l
- coracohumeral
- transverse humeral (holds biceps tendon in place)
7
Q
What is the coracoacromial arch? What does it do?
A
Coracoacromial ligament + acromion + coracoid process
Prevents upper displacement of the humerus
8
Q
What is the least stable part of the glenohumeral joint? What results from this?
A
Inferior
Anterior dislocation of shoulder
9
Q
What are the different components of the elbow joint?
A
CAPSULE =
1st layer: ulnar & radial collateral ligaments, anular ligament of radius (supports posteriorly)
- weak anteriorly & posteriorly
- strengthened medially & laterally by collateral ligaments
- elbow and proximal radioulnar joint share capsule
2nd layer: synovial membrane
Ulnar collateral ligament = anterior cord-like band (strongest) + posterior fan-like band + oblique band
Radial collateral ligament = fan-like; blends with anular ligament
10
Q
Describe the difference in position of the radius and ulna when pronated and supinated. Which bone does the hand deviate towards during abduction and adduction?
A
SUPINATED = radius and ulna are parallel
PRONATED = radius crosses over ulna (distal radioulnar joint is fixed)
ABDUCTION = radial deviation (limited by radial styloid process)
ADDUCTION = ulnar deviation
11
Q
Describe the articulation of the radius and carpal bones at the radiocarpal joint. What ligaments are present there?
A
Distal radius + articular disc articulate with the scaphoid, lunate, & triquetrium
Radial & ulnar collateral ligaments Palmar radiocarpal (ensures hand follows radius during supination Dorsal radiocarpal (ensures hand follows radius during pronation)
Ligamentous anterior border of articular disc ensures joint integrity during pronation/supination.
Sacciform recess allows twisting of capsule above ulna (which connects to articular disc)
12
Q
What is the definition of a fracture? What factors affect fracture healing?
A
FRACTURE = SOFT TISSUE INJURY with underlying break in bony cortex
LOCAL:
- degree of local trauma/bone loss
- area of bone affected (metaphyseal heals faster than diaphyseal)
- abnormal bone (infection/tumour/irradiation)
- degree of immobilisation
- disruption of vascular supply
SYSTEMIC:
- age
- nutrition
- general health e.g. diabetes
- hormones e.g. steroids
- drugs e.g. steroids
- smoking
13
Q
How can fractures be described?
A
- simple (closed) v.s. compound (open = bone penetrates skin and is exposed to air)
- location
- degree: complete (fragments completely separated) or incomplete
- articular extension: intra-articular fracture?
- comminution: no. of bone shards
- intrinsic bone quality: e.g. osteoporotic
- displacement, angulation, rotation (distal fragment relative to proximal fragment)
14
Q
What are the three components to fracture treatment?
A
REDUCE (fix fracture and bones)
HOLD (stabilise)
REHABILITATE (rest and reduce movement)
15
Q
What are some local complications of fractures?
A
EARLY:
- nerve/vascular injury
- compartment syndrome
- avascular necrosis
- infection
- surgical
LATE:
- delayed union
- non-union e.g. atrophic, hypertrophic
- malunion e.g. late arthrosis -> deformity
- myositis ossificans (calcification of muscle - bone growth)
- re-fracture
16
Q
What are some systemic complications of fractures?
A
- hypovolaemic shock
- fat embolism/thromboembolism
- acute respiratory distress syndrome (acute respiratory failure following a precipitating event)
- disseminated intravascular coagulation (overstimulation of blood clotting mechanisms -> generalised coagulation -> blood clotting factors used up -> spontaneous bleeding)
- osteoporosis
- joint stiffness
- chronic regional pain syndrome
- abnormal biomechanics
- osteoarthrosis (destruction of joints)
17
Q
What is the definition of a sprain? What is the treatment for a sprain?
A
SPRAIN = damage to a ligament (complete or partial) due to forces which stress the ligament
Treatment: RICE
Rest, Ice, Compression, Elevation
18
Q
What is the definition of a dislocation?
A
DISLOCATION = complete loss of continuity of the articulating surface of the joint
19
Q
What is the definition of subluxation?
A
SUBLUXATION = partial loss of continuity of the articulating surfaces of the joint
20
Q
Describe the features of the hip joint? What increases its stability?
A
- supports body weight when standing
- ball and socket synovial joint (large range of movement)
- most stable joint in body
Acetabular: acetabular labrum deepens acetabular fossa (fibrocartilaginous rim attaches to margin of acetabulum)
Ligaments:
- transverse acetabular ligament strengthens inferior part of acetabulum below acetabular notch
- ligament of head of femur carries small branch of obturator artery which contributes to the blood supply of head of femur
- iliofemoral (strongest, protects superiorly & anteriorly), pubofemoral (protects anteriorly & inferiorly; prevents overabduction), ischiofemoral (weakest, protects posteriorly)
(spiral - when joint is extended ligaments become taut; stabilising joint and reducing amount of muscle energy required to maintain a standing position)
Joint capsule
Muscles
21
Q
What are some of the functions of the vertebral column?
A
- centre of gravity (weight of body projected into lower limbs)
- attachments for bones (supports the head, ribs, & upper limbs)
- attachment for trunk muscles (upright position determined by continuous low-level contraction of trunk muscles to support body weight)
- conduit for spinal cord (allows segmental nerves to leave or join)
22
Q
How does the curvature of the vertebral column change throughout life?
A
FOETAL: Primary curvature (anterior concavity/flexion) throughout entire column
YOUNG ADULT: Primary curvature (anterior concavity/flexion) maintained in thoracic and sacral regions Secondary curvature (posterior concavity/flexion) in cervical and lumbar regions
OLD AGE:
Secondary curvatures disappear and continuous primary curvature re-establishes
Vertebral column closes up again
23
Q
What are the special features of the cervical vertebrae (apart from C1 & C2)?
A
- smallest vertebrae
- bifid spinous process
- oval transverse foramen in transverse process (foramen transeversarium)
- vertebral artery passes through foramen (except C7 - smaller accessory vertebral veins)
- large vertebral foramen
24
What are the features of the atlas (C1)?
- articulates with skull above (atlanto-occipital joint) and axis below (atlanto-axial joint)
- no body or spinous process
- widest cervical vertebra
- fused with axis to form dens/odontoid process
25
What are the features of the axis (C2)?
- strongest cervical vertebra
- rugged lateral mass and large spinous process
- dens prevents horizontal displacement of axis
26
What are the special features of the thoracic vertebrae?
- intermediate size (increase in size as you move downwards)
- demifacets on the sides of the body (articulate with head of rib)
- costal facets on transverse processes (except T11 & T12) articulate with tubercle of rib
- small circular vertebral foramen
27
What are the special features of the lumbar vertebrae?
- largest vertebrae
- lack of foramina on transverse processes
- lack costal facets on side of body
- small triangular vertebral foramina
28
What are the general characteristics of vertebrae?
PEDICLE = part of neural arch between body and transverse process
TRANSVERSE PROCESS = lateral (one on each side)
LAMINA = part of neural arch between transverse process and spinous process
SPINOUS PROCESS = midline and posterior
SUPERIOR & INFERIOR ARTICULAR FACET = lined by cartilage; allow synovial joints between neural arches of adjacent vertebrae (strengthened by ligamentum flavum)
SUPERIOR & INFERIOR VERTEBRAL NOTCH
29
How many vertebrae are there in each segment of the spine?
CERVICAL: 7
THORACIC: 12
LUMBAR: 5
SACRAL: 5 (fused)
COCCYX: 4 (fused)
30
Describe the features of the intervertebral discs. Which vertebrae are they present in?
Disc of tissue separating successive vertebrae between C2/3 and L5/S1
Symphyses (secondary cartilaginous joint)
- does not ossify (maintains flexibility)
- shock absorber for the skull
- increase in size as you move down
- wedge shape accounts for secondary curvatures (thoracic/lumbar: thickest anteriorly and thinnest posteriorly)
Annulus fibrosis surrounding (series of annular bands with varying orientations - outer = collagenous inner = fibro-cartilaginous) is the shock absorber
Nucleus pulposus centre (water reservoir for disc - changes in size throughout day depending on water distribution in disc)
31
What are the different ligaments present in the vertebral column? Where are they attached?
- ligamentum flavum: joins lamina of adjacent vertebrae; stretched by flexion of spine (elastic)
- anterior longitudinal ligament: united to periosteum of the vertebral bodies; free over intervertebral discs (stronger than posterior, broadens downwards)
- posterior longitudinal ligament: united to intervertebral discs; free over vertebral bodies (separated by basivertebral veins) (narrows downwards) (serrated margins)
- supraspinous ligament: joins tips of adjacent spinous processes; taut during flexion of spine (fibrous)
- interspinous ligament (lumbar only)
- facet capsulary ligament
- intertransverse ligament
32
What are the factors which "lock" the knee in the extended position whilst standing? Why is this desirable?
- joint surfaces more stable in extension (flat surface articulation instead of rounded in flexion)
- medial rotation of the femur on the tibia in extension tightens all ligaments (unlocked by popliteus muscle which initiaes lateral rotation)
- centre of gravity passes anterior to knee joint
Reduces the amount of muscle work required to maintain the standing position
33
Describe the ligaments present in the knee joint.
Intra-capsular =
CRUCIATE: anterior and posterior (intercondylar region of knee)
- prevent anterior and posterior displacement of the tibia related to the femur respectively
- anterior is weaker; posterior is main stabiliser in flexed knee
- anterior prevents hyperextension; posterior prevents hyperflexion
Extra-capsular =
COLLATERAL: extend from femoral epicondyles; reinforced by ilio-tibial tract
- lateral: cord-like (attached to lateral surface of fibular head)
- medial: flat band (attached to medial condyle of tibia & MIDPOINT OF MEDIAL MENISCUS)
PATELLAR: continuation of quadriceps femoris tendon (inferior to patella) (anterior)
OBLIQUE POPLITEAL (posterior) = extension of semimembranosus tendon (fibrous membrane)
ARCUATE POPLITEAL (posterior) = .....
TRANSVERSE LIGAMENT OF KNEE = connect menisci
34
Can cartilage be converted to bone?
NO - cartilage is REPLACED by bone
| endochondral ossification
35
What are the mechanical features of bones?
Rigid framework -> SUPPORT; PROTECTS INTERNAL ORGANS
Anchoring points for muscles -> MOVEMENT
Lever at joints -> MOVEMENT
36
What is responsible for the appearance of tuberosities, tubercles, ridges, and grooves?
Tuberosities, tubercles, & ridges = mechanical forces resulting from attachment of muscles, tendons, and ligaments to bone
Grooves = pressure from adjacent structures e.g. nerves & blood vessels
37
Give examples of bones that develop by endochondral ossification or intramembranous ossification.
ENDOCHONDRAL = long bones e.g. humerus, radius, ulna
INTRAMEMBRANOUS = flat bones e.g. clavicle
38
Of the rotator cuff muscles, which is the most vulnerable to injury and why?
Supraspinatus
Tendon passes under acromion of scapula and the acromioclavicular joint (fixed space)
Bursitis/excessive use of muscle fills space -> impingement of tendon during abduction
Relatively avascular -> poor healing and possible degeneration
39
What is compartment syndrome? How is it treated?
Raised pressure within an enclosed fascial space leading to localised tissue ischaemia e.g. Fracture bleeds, accumulation of blood causes increased pressure
Excessive pain, passive stretch pain
Compression: veins -> nerves -> arteries
Therefore late neurovascular changes i.e. when pulse is lost it will be too late to save limb
Surgical decompression
40
What is Pearson's rule?
Healing times for fractures
CHILD ADULT
Upper limb: 3 weeks 6 weeks
Lower limb: 6 weeks 12 weeks
41
What are two types of fracture which commonly occur in children?
GREENSTICK =
- incomplete fracture of long bone (only one side of bone fractured)
- convex side fractured
- caused by angulation longitudinal force/perpendicular force (causing bending)
TORUS ("buckle fracture") =
- incomplete fracture of long bone (only one side of bone fractured)
- characterised by bulging cortex
- due to excessive axial loading causing trabecular compression
42
What is a stress fracture? Give some examples of when this might occur.
Repetitive/abnormal non-violent application of heavy load ("fatigue") causing fracture
Marathon runners
Soldiers: "march fracture" - distal third of metatarsal
Hikers - inferior third of tibia fractured
43
Describe the tissue and shape of the menisci of the knee joint, and give some examples of their function.
C-shaped fibrocartilage
Improves congruency between femoral and tibial condyles during joint movements (reduces friction & spreads load of body weight)
44
Why is the medial meniscus most commonly torn in those who play sports? Why can "locked knee" be a symptom of a torn meniscus?
Tibial collateral ligament is attached to medial meniscus. Frequently torn whilst twisting flexed knees e.g. whilst running
A piece of the torn meniscus can be caught in the knee joint and wedge it, so the joint surfaces can no longer move
45
What is the purpose of the retinacula of the wrist and the ankle?
Prevent "bow-stringing" of tendons during movement
46
What are the functional purposes of the ankle joint?
- establishes a broad-base for supporting the entire body weight
- shock-absorber when landing
- must be able to lift entire bodyweight during initiation of movement
note: must be stable when weight-bearing and moving, loose to permit displacement of the joint, permit moving on flat and uneven surfaces
47
Describe the articular surfaces of the ankle joint. How would you describe the joint?
Tibia: superior & inferior
Fibula: lateral
Talus: inferior, infero-medial, & infero-lateral
ROLLING-HINGE (SYNOVIAL) JOINT:
Mortise (box-shaped recess) formed by tibia and fibula which accommodates the talus (tenon)
Axis of rotation is not fixed (therefore dorsiflexion and plantarflexion can happen)
48
Describe the articular surfaces of the tibia and fibula.
Proximal tibio-fibular (synovial)
Interosseous membrane
Tibio-fibular syndesmosis (fibrous)
- anterior ligament
- posterior ligament (deepens articular surfaces)
+ transverse tibio-fibular ligament
49
What are the weight-bearing and joint stabilising surfaces of the ankle joint?
Weight-bearing:
- tibia
- talus
Joint stabilising:
- medial & lateral malleoli
- distal tibio-fibular posterior ligament
- transverse tibio-fibular joint
50
Why do we need arches in the foot? Describe the arches.
2 main arches (anterior->posterior):
- medial: 1st-3rd metatarsals, cuneiforms, navicular, talus, calacaneus
- lateral: 4th-5th metatarsals, cuboid, calcaneus
+ 1 transverse arch (medial->lateral): articulations of tarsals to metatarsals (stengthened by tendons of muscles in foot)
Note: (medial?) arch created by the tendons of tibialis posterior, flexor digitorum longus, and flexor hallucis longus moving from the posterior medial malleolus to the sole of the foot
51
Describe the bones of the foot.
TARSAL BONES (7):
- short bones (irregular, cuboidal, 6 articulating surfaces)
- most important for the movements of the foot and ankle
- no muscular attachments (all ligamentous)
TALUS:
- long axis of rotation of ankle joint (directed antero-medially)
- head, neck, body
- dorsal surface (trochlear): rounded superiorly, superior convex edges medially & laterally, concave central portion from side-to-side; wider in front than behind
- ventral surface: talus forms sub-talar/talo-calcaneal joints with the calcaneus (anterior: convex talus fits concave calaneus; posterior: concave talus fits convex calcaneus) (allows side-to-side motion: eversion & inversion)
- tarsal canal: deep groove running antero-laterally
52
What are the movements of the ankle joint?
DORSIFLEXION/PLANTARFLEXION: narrowing/widening of the angle subtended between anterior surface of the leg and the dorsal surface of the foot
- dorsiflexion (10-30 degrees): broader anterior portion of trochlear fully occupies the mortise + tibio-fibular syndesmosis + malleoli spread apart & lateral malleolus everted (STABLE)
- plantarflexion (20-50 degrees): narrower part of trochlear partially occupies the mortise (little rotation, abduction, adduction - UNSTABLE)
INVERSION/EVERSION: lifting of sole of the foot so it is pointed towards/away from the midline (allows use to walk on uneven/sloping ground using the sides of the feet)
- inversion (30 degrees)
- eversion (10 degrees)
Medial & lateral rotation
53
Describe the medial and lateral ligaments of the ankle joint.
Medial (deltoid): triangular, strongest, reinforced by tendons of tibialis posterior and flexor digitorum longus
- SUPERFICIAL: tibio-navicular, calcaneo-tibial, talo-tibial
+ deep
Lateral: 3 separate bands
- anterior & posterior -> talus
- intermediate -> calcaneum
54
What ligaments make up the greater and lesser sciatic foramina?
GREATER = sacrospinous ligament (ischial spine -> sacrum)
LOWER = sacrospinous ligament + sacrotuberous ligament (sacrum -> ischial tuberosity)
55
What are the articulations of each hip bone?
Sacroiliac (ilium -> sacrum)
Pubic symphysis (pubis of one hip bone -> pubis of other hip bone)
Hip joint (articulation with head of femur)
