Orthopaedics Flashcards
The superficial femoral artery passes through what canal in the thigh?
It then exits the canal and becomes the popliteal artery at what structure?
Hunter’s canal (also called adductor canal, subsartorial canal)
The adductor hiatus (hole made between adductor magnus hamstring part and femur)
What are the compartments of the thigh, and their innervation? (include exceptions)
Anterior - femoral nerve
Posterior - sciatic nerve
Medial - Obturator nerve (except adductor magnus hamstring part (tibial n.) and pectineus (femoral n.)
What are the compartments of the leg, and their innervation?
Anterior - deep fibular nerve
Posterior - tibial nerve
Lateral - superficial fibular nerve
What ligaments make up the lateral collateral ligament of the ankle?
Anteriortalofibular +posterior talofibular + calcaneofibular ligament
What tendons make up the pes anserinus?
Sartorius + Gracilis +Semitendinosus
Say Grace before Tea
What is a maisonneuve fracture?
Proximal fibula # associated with an unstable ankle injury (deltoid ligament injury or tear in distal tibiofibular syndesmosis + med malleolus #)
What ligaments make up the medial collateral ligament of the ankle?
What is another name for this complex?
Anterior tibiotalar + posterior tibiotalar + tibiocalcaneal + tibionavicular ligaments
Deltoid ligament
Which gene is frequently associated with rheumatoid arthritis?
HLA-DR4
What are the 4 pathological stages of RA?
1) Preclinical: raised ESR, CRP, RF detectable before clinicial Sx
2) Synovitis: synovial membrane inflammation & thickening. Painful, swollen joints
3) Destruction: persistent inflamm causing joint & tendon destruction, articular cartilage & bone erosion, pannus, synovial effusion
4) Deformity: articular destruction + capsular stretching + tendon rupture -> progressive instability and deformity
The classic ‘rheumatoid’ deformities are (radial/ ulnar) deviation of the fingers and (radial/ ulnar) deviation of the wrist
Ulnar deviation of fingers
Radial deviation of wrist
Juvenile Chronic Arthritis is also known as ______ disease
Still’s disease
True or false: in children, malunion can sometimes be partly corrected by growth
True
What organisms are implicated in triggering reactive arthritis?
GI or GU infections: Salmonella, Yersinia, Chlamydia, Shigella, Campylobacter
What is Kienbock’s disease?
Avascular necrosis of the lunate. Most common in 20-40yo males, exact cause unknown
What gene is associated with the seronegative spondyloarthropathies?
HLA-B27
Describe the pathological steps of ankylosing spondylitis
Inflammation -> granulation tissue formation -> erosion of cartilage/ bone -> replacement with fibrous tissue -> ossification of fibrous tissue -> ankylosis
Which disease is diagnosed based on needle-shaped crystals with strong negative birefringence?
Gout (urate crystals)
Which disease is diagnosed based on rhomboid-shaped crystals with weakly positive birefringence
Pseudogout aka calcium pyrophosphate dihydrate deposition disease (calcium crystals)
__% of monosodium urate is derived from endogenous purine metabolism and __% from purine-rich foods in the diet
70%
30%
What are the side effects of colchicine?
Diarrhoea, N&V
What are 4 MSK complications of RA?
Infection
Tendon rupture
Joint rupture
Secondary OA
Infliximab, etanercept and adalimumab are all _____[drug class]
TNF inhibitors
Which type (mechanism) of pelvic fracture is associated with the largest amount of blood loss?
Ant-post compression (APC)
What are the 2 classification systems for pelvic fractures?
1) Young-Burgess based on mechanism
APC (ant post compression), LC (lat compression), VS (vertical shear), combined
2) Tile Classification of severity
Stable, partially stable, unstable
_____ hormone stimulates bone growth whilst ____ hormone promotes stable physeal fusion
Pituitary growth hormone
Gonadal hormone
What percentage of Paget’s disease undergoes malignant transformation into osteosarcoma?
Approx 1%
Describe the difference between Paget’s disease of bone, osteomalacia and osteopetrosis
Paget’s disease of bone = disorganised bone remodelling with increased osteoclastic & osteoblastic activity aka problem with bone STRUCTURE
Osteomalacia = defective bone mineralisation d/t loss of inorganic material, producing brittle, soft, weak bones aka problem with bone MINERALISATION
Osteopetrosis = genetic disorder decreasing bone resorption, producing abnormally dense bones aka problem with bone RESORPTION
Name two drugs used for Paget’s disease of bone
Any of:
NSAIDs for analgesia
Bisphosphonates (reduce bone turnover)
Calcitonin (reduce osteoclast activity)
Patients with sickle cell anaemia are prone to an osteomyelitis infection by ______ (organism)
Salmonella typhi
What organism is the most common cause of osteomyelitis? (in adults & children) Which antibiotic is routinely given?
Staph aureus
Flucloxacillin
Septic arthritis usually affects (small/ large) joints?
Large
Mycobacterium tuberculosis has a predilection for ______ & _________ joints
vertebral bodies & large synovial joints
What are the high-risk injuries for the development of compartment syndrome?
Fractures of the elbow, forearm bones, prox 1/3 of tibia ad multiple hand/ foot #s (Apley’s pg 354)
Patellar dislocation usually happens (medially/laterally)
Laterally
Because knee is normally angled in slight valgus, there is natural tendency for the patella to pull towards the lat side when the quadriceps muscle contracts (Apley’s p446)
Patellar dislocation can be associated with torn ____ and ____
Medial retinacular fibres (part of quadriceps expansion) and med patellofemoral lig (MPFL)
What factors (4) predispose to recurrent patellar dislocation
Generalised joint laxity
Marked genu valgum
Unduly high or small patella
Under-development of lat femoral condyle + flattening of intercondylar groove
List 6 conditions that predispose to pathological fractures
- Osteoporosis/ osteopaenia
- Osteomalacia
- Paget’s disease of bone
- Osteogenesis imperfecta
- HyperPTH
- Neoplasm (myeloma, osteosarcoma)
What are the 4 stages of fracture bone healing?
1) Haematoma (wk 1)
2) Soft pro-callus (wk1-2): uncalcified fibrous tissue/ cartilage
3) Hard bony callus (wk2-4): spongy woven bone
4) Remodelling (>wk4): lamellar bone, weight-bearing
Arterial injury is associated with what 2 fracture locations? (joint + bone for each)
Knee/ femur
Elbow/ humerus
What are 4 injuries at high-risk of developing compartment syndrome?
Elbow # Forearm # Prox 1/3rd tibial # Multiple #s of hand/ foot (Apley's p354)
Muscle dies after ____ hrs of ischaemia
4-6 hours
Nerve injury is more likely to be complete in (open/ closed) fractures?
Open
Malalignment of a fracture >___ degrees in any plane may cause asymmetrical loading of the join & 2oOA
15 degrees
Any fracture with an intra-articular step of the radiocarpal joint >___mm is also advised to be surgically corrected.
> 2mm
Explain the Gustilo & Anderson Classification System
Used to classify open fractures
I: clean wound <1cm, minimal muscle contusion
II: 1-10cm wound, soft tissue damage but minimal/ moderate crushing
IIII: >10cm wound, extensive soft tissue damage affecting neurovascular/ muscular/ skin tissue
- A: adequate soft tissue flap
- B: needs soft tissue flap
- C: vascular injury requiring repair or high E trauma/ segmental #/ contaminant exposure
The treatment of cauda equina syndrome is _____
urgent surgical decompression <48hrs via discectomy or laminectomy. The sooner this is performed, the better the outcomes. Unfortunately, bladder dysfunction may not be completely resolved.
What is the classification system for AC joint injury?
Rockwood Classification
- I: AC lig sprain (clavicle not elevated wrt acromion)
- II: AC lig tear + CC lig sprain (clavicle elevated but not above sup border of acromion, CC distance <25%)
- III: AC + CC lig tear; clavicle elevated above sup border of acromion, CC distance 25-100%
- IV: AC + CC lig tear; clavicle displaced posteriorly into trapezius
- V: AC + CC lig tear; clavicle elevated, CC distance >100%
- VI: AC + CC lig tear; clavicle displaced inferiorly behind coracobrachialis/ biceps
What is Wolff’s law?
States that bone in a healthy person or animal will adapt to the loads under which it is placed i.e. if loading increases, the bone will remodel to become stronger
The most common malignant lesions in bone are ____
Metastatic tumours
Mostly Prostate, breast, Kidney, Lung, Thyroid (‘Pb KTL’)
What is the most useful imaging technique for ?bone tumour
Plain X-rays (Apley p101)
But may not be relied upon for definitive diagnosis
On plain Xray, stippled calcification inside a vacant area is characteristic of _____ tumours
Cartilage tumours
What are the common sites for osteosarcoma? (3) Where does it often metastasize
1) Distal femur
2) Proximal tibia
3) Proximal humerus
Mets to lung (~10% already present at time of Dx)
Chondrosarcoma most commonly affects the ____ and ____
Pelvis and scapula
Osteochondromas are also known as _____
Cartilage-capped exotosis
True or false: chondrosarcomas are responsive to chemo/ radiotherapy
False - they don’t respond to either
What is the classic presenting triad in fat embolism syndrome and over what time frame does it usually develop?
Hypoxaemia/ resp compromise + confusion + petechial rash
Develops over 24-72hrs post-injury
Cancellous bone heals a) (faster/ slower) than cortical bone.
Transverse fracture heals b) (faster/ slower) than spiral fracture
a) faster
b) slower
What are the risk factors for DDH?
'BOFFF' > Breech position (>34/40) > Oligohydramnios > Female > FHx (> First born)
Congenital scoliosis is defined as a lateral curvature of the spine with a Cobb angle of ____
≥10 degrees
Cobb’s angle: lines drawn along the endplates of the uppermost and lowest end vertebrae of the curve deformity & angle between their intersection is measured
Spinal stenosis is classically aggravated by a) _____ and relieved by b) _____
a) Standing & walking
b) Sitting & bending forwards
The most common curvature in adolescent idiopathic scoliosis is ____
Right thoracic
List at least 4 conditions associated with neuromuscular scoliosis. Describe the typical deformity
Any of: 1) Poliomyelitis 2) Syringomelia 3) Muscular dystrophy 4) Cerebral palsy 5) Friedreich's ataxia 6) Lower MND Typical deformity is long, convex curve towards weaker side
What are Ennekings 4 rules?
Used to determine likelihood of bone lesion being malignant
Asks 4 Questions
1) Where is the lesion?
2) What is it doing to the bone?
3) What is the bone doing to it?
4) Are there any clues to its histological Dx (what is its matrix)?
Babies with talipes equinovarus (‘club foot’) should always be checked for _____ (2 other conditions)
Congenital hip dislocation and spina bifida
Unclear aetiology, but FHx is a risk factor. 50% are bilateral, M>F
What are 3 causes of stiff (‘rigid’) flat feet?
1) Inflammatory disorder of joint
2) Neuromuscular disorder
3) Tarsal coalition
Hallux valgus is usually a) unilateral or b) bilateral
B) bilateral
Which joint is most commonly affected in diabetic neuropathic joint?
Midtarsal
followed by MTP and ankle
What is the first ROM lost in OA of the hip?
Internal rotation
Genu varum (bow legs) is normal under the age of ___ and usually corrects by age ___
Normal <2yo
Corrects by 3yo
Cauda equina syndrome presents as an a) UMN or b) LMN disorder
b) LMN
