Orthopaedics Flashcards
Name the three bones that make up the acetabulum
Ischium
Ilium
Pubis
Describe the classification of hip fractures, and which type causes risk of AVN
Intracapsular (proximal to the trochanters)
Extracapsular (intra-trochanteric or subtrochanteric)
DISPLACED INTRAcapsular fracture = risk of AVN
What are the presenting features of a NOF #
Pain - groin, thigh, referred to knee
Leg length shortened and externally rotated
Describe the main blood supply to the head of femur
Retrograde
From medial circumflex femoral artery
What is the mortality of hip fractures at 1 year?
30%
What investigations should be carried out for a hip #
X-ray (AP and lateral views) Bloods: FBC, U&E, coag, G&S, CK (if long lie) Urine dip (cause of fall) CXR ECG
Describe the management of NOF#
A-E Analgesia (opioids, or regional -> fascia-iliaca block) Definitive management -> surgical: Total hip arthroplasty Hemiarthroplasty
Describe the risk factors for osteoporosis (overlap with RFx for hip #!)
S - steroids H - hyperthyroid, hyperparathyroid A - age increasing T - low testosterone T - thin (less weight-bearing) E - early menopause R - renal/liver failure E - erosive/inflammatory bone disease D - diet (low vitamin D/Ca)
Describe the bones that make up the pelvic ring
Sacrum
+
Ilium, ischium, pubis
What is the polo-mint rule
In Pelvic ring fractures, always look for a second fracture site
Describe the management of pelvic #
Stabilisation -> prevent blood loss
Pelvic binder initially will hold the pelvis in place until definite stabilisation -> for attempted clot formation
Fractures fixed definitively with plates/bolts
What are the complications of pelvic #
Risk of damage to pelvis structures: ○ Bowel ○ Bladder ○ Genitals ○ Nerves Urological injury Venous thromboembolism Long-standing pelvic pain
what is the rule when diagnosing patella tendon rupture?
if the patellar tendon is longer than the length of the patella +/- 20%
Describe the function of supraspinatus
Helps adduct the first 15 degrees, then deltoid aids
Describe the function of infraspinatus
External rotation
Describe the function of subscapularis
Internal rotation and adduction
Describe the function of teres minor
External rotation at shoulder
Why are knee dislocations emergencies?
Risk of damage to popliteal artery
Describe the management of femoral fractures
The longest bone in the body therefore can bleed a lot and cause hypovolaemic shock
Reduce and splint • Thomas-type splint -> fixed traction • Reduces fracture movement • Reduces bleeding • Reduces risk of damage to nerves/vessels • Improves pain
Describe the parts of a long bone
Epiphysis
Growth plate
Metaphysis
Diaphysis
Describe Bohler’s angle
draw two lines tangent to the calcaneous, should be 20-40o
To assess for normality of the ankle
Describe a stable vs unstable ankle fracture
Stable fractures = have damage to only one side of the joint e.g. medial or lateral
○ Therefore no disruption to the ankle joint mortice and the risk of degenerate change in the future is low
Unstable fractures = damage to both medial and lateral sides
○ May be disruption of the ankle joint mortice and risk of degenerative change in the future is high
○ These fractures require to be stabilised, usually with internal fixation
Describe the bones of the hindfoot, midfoot and forefoot
Hindfoot = talus + calcaneus
Midfoot = Navicular, cuboid, cuneiforms
Forefoot = metatarsals and phalanges
What is a Lisfranc fracture
Dislocation of the midfoot between the tarsal bones (navicular, cuboid and cuneforms) and the base of the metatarsals
Commonly missed!
List the components to describe an x-ray
SOC-F-DAP
Patient details, this is an X-ray of SITE and which side Open or closed Fragmented? Direction - transverse/oblique/spiral? Articular involvement? Position (displaced/undisplaced)
Describe the radiographic findings of OA
LOSS
Loss of joint space
Osteophytes
Subchondral cysts
Subchondral sclerosis
What is a colle’s fracture
Transverse distal radius fracture, caused by FOOSH, with dorsal displacement
What is a Smith’s fracture?
Transverse distal radius fracture, caused by falling onto flexed hand, with volar displacement (opposite of Colles)
Describe a Galeazzi and Monteggia #
GRIMUS!
Galeazzi - (radial inferior) i.e. radial # with displaced dislocated radio-ulnar joint
Monteggia - (ulna superior) i.e. ulnar fracture with dislocated head of radius (at elbow e.g. proximal/superior)
What is the most dangerous infective agent of an open fracture?
Clostridium perfringes -> causes gas gangrene/renal failure
Describe the gardner classification of NOF#
Grade 1 = incomplete #
Grade 2 = complete # without displacement
Grade 3 = complete # with partial displacement
Grade 4 = complete # with full displacement
What examination findings may you get on examination of an OA hip
Pain (buttock, groin, referred to thigh) Antalgic gait/trendelenberg Tenderness over hip reduced ROM (esp. internal rotation) Positive thomas' test
What are the x-ray findings of OA?
LOSS loss of joint space osteophytes subchondral cysts subchondral sclerosis
What are the x-ray findings of RA?
SPADES Soft tissue swelling periarticular erosions absent osteophytes deformity erosion subluxation
Describe the management of OA
Non-op:
Education, weight loss, walking aids, analgesia, non-weight bearing exercise
Operative:
THR
List the risk factors for avascular necrosis
Traumatic: Fractures, dislocations, SUFE
Non-traumatic: Alcohol, steroids, bone malignancy, connective tissue disorders
What is SUFE
Slipped upper femoral epiphysis = fracture through the capital femoral growth plate and the epiphysis slips posteriorly and inferiorly
common in 10-16yr olds during rapid growth
RFX: Male, obesity
What are the radiographic features of SUFE?
Steel sign = a shadow behind the superior femoral neck
Shenton’s line disrupted
Line of Klein - fails to intersect the superior femoral epiphysis
What is DDH?
Developmental dysplasia of the hip = abnormal hip development resulting in shallow under-developed acetabulum, and possible subluxation/dislocation
What are the RFx for DDH and what are its tests
Female, first born, breech position, FHx
Test with Barlow’s and Ortolani tests
Describe the principles of fracture management
Resuscitation (A-E)
Reduction
Restriction
Rehabilitation
Describe the Gardner classification of intracapsular hip fractures
Stage I: Incomplete fracture of the neck (so-called abducted or impacted)
Stage II : Complete without displacement
Stage III: Complete with partial displacement. Fragments are still connected by posterior retinacular attachment and there is malalignment of the femoral trabeculae
Stage IV : This is a complete femoral neck fracture with full displacement, the proximal fragment is free and lies correctly in the acetabulum so that the trabeculae appear normally aligned.
Describe the benefits and cons of hemiarthroplasty vs THR
Hemi benefits:
Shorter operation
Lower risk of post-op dislocation (as the replaced head is larger than the head put in during a THR)
Hemi cons:
Long term pain
Worse mobility
Define staging and grading
Staging - working out how far a tumour has spread (e.g. pan-CT plus CT/MRI of organs involved)
Grading - usually from a biopsy sample, to assess how well differentiated/the cell types/how aggressive a cancer is. Predicts cancer behaviour and patient prognosis.
What cancers commonly metastasise to bone?
think of 5 paired organs!!
- thyroid
- lung
- breast
- renal
- prostate
What boney sites do cancers commonly metastasise to?
Vertebrae
Proximal metaphyses
Describe the difference between T1 and T2 weighted MRI scans
T1 - fat is bright
T2 - fat and water is bright
What nerve root is likely to be affected by a L4/5 disc paracentral herniation?
The transiting L5 nerve root
What nerve root is likely to be affected by a L4/5 disc foraminal (lateral) herniation?
The exiting L4 nerve root
In layman’s terms describe osteoporosis, Paget’s disease and Rickets/Osteomalacia
Osteoporosis = not enough bone (but normal quality)
Paget’s disease = XS bone (but normal quality)
Osteomalacia = normal quantity of bone but defective mineralisation (after skeletal maturity)
Ricket’s = normal quantity of bone but defective mineralisation (before skeletal maturity)
What is the role of OGP (osteoprotegerin)
OPG is released from OB
Prevents XS bone resorption as it binds to RANK-L (also released from OB) and stops RANK-L converting pre-OC into OC, therefore limiting the formation of mature OC’s
What are the most common # in osteoporotic patients?
Hip, femur, spine and radial
Describe DEXA scans and the T/Z score result
DEXA = dual energy x-ray absorptiometry
T-score = The score is made from comparing your result to a ~30yr old young healthy adult (so not age matched!)
Z-score = The score you get is by comparing your result to an age matched healthy control (e.g. if you are 45 then your score is compared to a 45yr old)
Describe the standard deviations generated from DEXA scan
SD’s use the T-score (not aged matched)
0 to -1.5 = normal
-1.5 to -2.5 = osteopenia
< -2.5 = osteoporosis
< -2.5 with # = ‘defined’ OP
Describe the role of calcitonin
Opposes the action of PTH
- Reduces OC activity (less bone resorption and less Ca released into bloodstream)
- Reduces Ca absorption at the DCT
Describe the two main forms of rickets/osteomalacia:
Vitamin-D dependent and vit-D independent
Dependent causes:
- reduced sun exposure
- reduced dietary intake
- reduced intestinal absorption (e.g. IBD)
Independent causes:
- kidneys not working (i.e. there is enough vit D in the body but it cannot be absorbed)
Define Paget’s, it’s phases and the bony sites commonly affected
Bone remodelling due to increased OC activity
3 phases: lytic/mixed/sclerotic
Bones affected: skull, spine, pelvis, femur
What are the S/Sx of Paget’s
Joint/bone pain
Deformity
Isolated raised ALP
Headaches/deafness (due to entrapment of CN in growing skull)
Loss of visual fields (bony growth at optic chiasm)
Can cause high output cardiac failure
What are the typical X-ray features of Paget’s
Mixture of lytic and sclerotic disorganised bone
(Due to accelerated OC resorption of bone, followed by disordered and XS formation)
Acetabular protrusion can occur 2o to Paget’s
What is the blood supply of the scaphoid?
Branch of radial artery (enters distally and travels proximally)
Name the 3 anatomical parts of the scaphoid bone
Distal pole
Waist
Proximal pole
What makes up the borders of the anatomical snuffbox?
EPL (ulnar side)
EPB + APL (radial side)
What are the important contents of the anatomical snuffbox?
Radial artery
Radial nerve
Cephalic vein
Describe risk factors for carpal tunnel syndrome
Previous wrist trauma OCP Pregnancy RA Cardiac failure Hypothyroidism
What is the management for carpal tunnel syndrome
- Splintage and rest
- Steroid injection
- Surgical release
Describe the management of a hip fracture based on its location
The management of the fracture depends on its location.
Intracapsular fractures:
- Replacement arthroplasty (hemiarthroplasty or total hip replacement) for patients with a displaced intracapsular fracture.
- Total hip replacements for patients with a displaced intracapsular fracture who:
- > Are able to walk independently out of doors with no more than the use of a stick; and
- > Are not cognitively impaired; and
- > Are medically fit for anaesthesia and the operation.
Extracapsular fractures:
- Extramedullary implants e.g. a sliding (dynamic) hip screw for trochanteric fractures above and including the lesser trochanter
- Intramedullary e.g. pin and plate or extramedullary internal fixation for subtrochanteric fractures
What is Froment’s sign?
Ulnar nerve weakness results in inability to hold paper between thumb and index finger/terminal phalanx has to compensate by flexing to hold on to the paper
Damage to which nerve is associated with claw hand?
Ulnar
What nerve roots make up the ulnar nerve
C8 & T1
What nerve roots make up the median nerve
C5, 6, 7, 8, T1
What nerve roots make up the radial nerve
C5, 6, 7, 8, T1
How is the motor function of the median nerve tested?
Thumb abduction
How is the motor function of the radial nerve tested?
Wrist extension
How is the motor function of the ulnar nerve tested?
Finger spread and don’t let them be pushed together!
What are the 3 principles of # management?
Resus
Reduce
Retain
Name and describe 3 tests for impingement syndrome
1) Painful arc test (painful abduction between 60-120)
2) Neer impingement test (pain on forward flexion >90)
3) Hawkins Kennedy test (pain when forward flex to 90 and then internally rotate)
