Bones & Joints Flashcards
What are some of the different features of bones? Give an example of each.
- 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
What are some of the different types of bone? Give an example for each.
- 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
What is the definition of a joint? What are the different types? Give an example of each.
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
What is the difference between rheumatoid and osteoarthritis? What area is affected in each?
RHEUMATOID ARTHRITIS = damaged fibrous capsule of synovial joint
OSTEOARTHRITIS = damaged hyaline cartilage of synovial joint
What factors affect the stability of joints?
- 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)
Why is the glenohumeral joint inherently unstable? What factors increase the stability of this joint?
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)
Describe the intra-capsular and extra-capsular ligaments of the glenohumeral joint.
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)
What is the coracoacromial arch? What does it do?
Coracoacromial ligament + acromion + coracoid process
Prevents upper displacement of the humerus
What is the least stable part of the glenohumeral joint? What results from this?
Inferior
Anterior dislocation of shoulder
What are the different components of the elbow joint?
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
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?
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
Describe the articulation of the radius and carpal bones at the radiocarpal joint. What ligaments are present there?
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)
What is the definition of a fracture? What factors affect fracture healing?
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
How can fractures be described?
- 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)
What are the three components to fracture treatment?
REDUCE (fix fracture and bones)
HOLD (stabilise)
REHABILITATE (rest and reduce movement)
What are some local complications of fractures?
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
What are some systemic complications of fractures?
- 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)
What is the definition of a sprain? What is the treatment for a sprain?
SPRAIN = damage to a ligament (complete or partial) due to forces which stress the ligament
Treatment: RICE
Rest, Ice, Compression, Elevation
What is the definition of a dislocation?
DISLOCATION = complete loss of continuity of the articulating surface of the joint
What is the definition of subluxation?
SUBLUXATION = partial loss of continuity of the articulating surfaces of the joint
Describe the features of the hip joint? What increases its stability?
- 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
What are some of the functions of the vertebral column?
- 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)
