SAQ Flashcards
What are 7 neurological causes of pes cavus aside from?
CMT
CP
Diastematomyelia
Stroke or closed head injury
Freidreich’s ataxia
Huntington’s chorea
Arthrogryposis
What are the 3 most common procedures performed after a terrible triad?
Column procedure
Radial head arthroplasty for failed ORIF
TEA
6 design features to reduce IM pressure during reaming?
Deeper flutes
Larger diameter bulb tip
Slower speed of rotation
Sharp reamer
455 stainless steel
Titanium nitride coating
8 risk factors for Pavlik harness failure?
Bilateral
Teratologic
Ortolani negative
Initiation of treatment after 7 weeks
Male
Inappropriate application
Femoral nerve palsy
Patient noncompliance
5 infantile disorders with thickened cortices/periosteal calcifications?
Caffey’s disease
Scurvy
Rickets
Hypervitaminoses (A and D)
Congenital syphilis
8 risk factors for Dupuytren’s disease?
Male
Advanced age
Manual laborer
Smoker
Alcohol
HIV
Diabetes
Anti-epileptics
6 indications for surgery in a Rheumatoid C-spine?
Progressive myelopathy
ADI >10mm static
ADI >4mm dynamic (ie: 4mm more on flex vs. ex view)
SAC <14mm
Tip of the dens past McRae’s line
Tip of the dens >5mm above McGregor’s line
>20% C3-C7 subluxation with neuro symptoms/severe pain
7 principles of tendon transfers?
Expendable donor tendon
Donor tendon has similar strength and excursion
Straight line of pull
Supple joint
One tendon performs one function
Synergistic function
Lose 1 point on power grade after transfer
Name 3 local complications related to metal toxicity
Pseudotumour
Metallosis (aseptic local necrosis secondary to metallic corrosion)
ALVAL (aseptic lymphocitic vasculitis associated lesion - T-cell mediated type IV hypersensitivity reaction to Co and Cr ions)
Name 4 principles for maintaining reduction in a length-stable pediatric femur fracture managed with Nancy nails
> 80% canal fill
More nails to increase rigidity
Pre-contour nails to achieve adequate spread at fracture site
Use end caps to improve axial stability
What’s an indication to do a metabolic work-up in SCFE?
Patient <10 yo or <50%ile for body weight
List 4 endocrine abnormalities associated with SCFE
Hypothyroidism
Panhypopitutiarism
Growth hormone deficiency
Renal osteodystrophy
Name 5 methods to reconstruct a zone 2 (periacetabular) pelvic lesion
Curettage and cementplasty
Conventional THA
THA with reinforcement ring/reconstruction cage
Harrington procedure (primary THA reinforced by 3 steel pins/screws from the iliac crest down and cement)
Megaprosthesis
List 6 complications of an HTO
Intra-articular fracture propagation
Recurrence of deformity (60% at 3 years)
Patella baja
Decreased posterior slope
Compartment syndrome (recurrent anterior tibial)
Malunion/non-union
3 advantages of a distal femoral locking plate over a DCS
Better fixation in osteoporotic bone
Better control of coronal-plane fractures
More bone preserving (screw removes a lot of bone)
6 radiographic features of FAI
Alpha angle >55
LCEA >39
Tonnis angle <0
Head-neck offset ratio <0.17
Crossover sign
Ischial spine sign
List 8 risk factors for infection in THA
Active infection
IVDU
Revision surgery
Diabetes
Obesity
Rheumatoid arthritis
Immunosuppression (HIV)
Smoker
List 8 radiographic features of aortic dissection on CXR
Widened mediastinum
Widened paraspinal stripe
Widened paratracheal stripe
Indistinct aortic contour
Right trachial deviation
Left depressed mainstem bronchus
Left apical pleural cap
Left large haemothorax
List 4 major and 4 minor criteria for fat embolism
1 major and 4 minor criteria required to make Dx.
Major: hypoxia, pulmonary edema, petechiae, CNS depression
Minor: fat in urine or sputum, tachycardia, fever, sudden indexplicable drop in platelets
List 6 orthopaedic features in the diagnostic criteria of Marfan’s
Pectus excavatum requiring surgery
Reduced elbow extension
Positive wrist and thumb signs
Scoliosis or spondylolisthesis
Protrusio
Medial displacement of medial malleolus (pes planus)
List 5 non-orthopaedic features of Marfan’s
Lens dislocation
Aortic dilatation
Aortic dissection
Mitral valve prolapse
Spontaneous pneumothorax
List 5 indications for immediate amputation in trauma
Medically unfit for surgery
Crush injury with warm ischemia time >6h
Crush injury with cool ischemia time >12h
Irreparable vascular injury
Complete laceration of sciatic or tibial nerve
List 3 methods of determining if a femoral neck fracture is anatomically-reduced in a young patient
Direct inspection through Smith-Peterson approach
Lowell alignment theory (head-neck should form an “S” on both the AP and lateral views)
Garden compression trabecular index (160 deg on AP and 180 deg on lateral)
List 8 surgical considerations in the management of severe hallux valgus
1st MTP OA?
1st TMT instability/OA?
Sesamoid OA?
Medial eminence prominence?
HVIA <9
DMAA <9
HVA <15
IMA <9
What are 10 risk factors for vision loss in spine surgery?
Male
Diabetes
PVD
Obesity
Preoperative anemia
Long procedure
Perioperative blood loss >1L
Hypotension
Prone positioning
No colloid used during resuscitation
What are the 4 principles of causality?
Strength of the association
Specificity of the association
Temporality
Reversibility
Explain the difference between blinding and concealment of allocation
Blinding: patient, their family, treating team and anyone involved in outcomes assessment is unaware to the intervention performed.
Concealment of allocation: individual who is enrolling participants does not know in advance which study arm each successive patient will be enrolled to.
List 4 indications for hemiresection and interpositional arthroplasty of the DRUJ
Painful arthritis (OA, RA, PTA)
Ulnocarpal impaction with radio-ulnar incongruity
Absence of longitudinal forearm instability
Absence of post-traumatic ulnar subluxation of the carpus
List 6 indications for MRI in juvenile scoliosis
Any child <10 with >20 degree curve
Short, sharp curve
Rapidly progressing curve
Asymmetric abdominal reflex
Upper motor-neuron signs
Associated cavus foot
List 3 risk factors for the development of metastasis in an isolated soft tissue sarcoma
High-grade tumour
Resection with positive margins
Local recurrence
Which 2 muscles are commonly transferred after a proximal humerus resection and endoprosthetic reconstruction?
Pectoralis major
Latissimus dorsi
Which 3 muscles require transfer after a proximal femoral resection and endoprosthetic reconstruction?
Iliopsoas
Short external rotators
Abductors
What % of resected and reconstructed (a) distal femoral and (b) proximal tibial tumours require a medial gastrocs flap for coverage?
(a) 25%
(b) 100%
What’s the overall survival of an endoprosthetic reconstruction at 10 years? Which location has the worst?
85% (worst for proximal tibia, best for proximal humerus)
Which 4 factors facilitate local high-grade sarcoma spread in the shoulder as compared to other joints?
Direct capsular extension
Spread along the LHBT
Fracture hematoma from pathologic fracture
Inappropriately-planned biopsy
If a proximal humerus tumour involves the axillary/brachial artery, what’s the implication?
Brachial plexus is also involved due to proximity to the artery (axillary vein, artery and brachial plexus are all within the axillary sheath), and so this is a contraindication to limb salvage
What are the 2 contraindications to a forequarter amputation?
Chest wall extension
Extension into the posterior triangle of the neck
Optimal position for wrist fusion? What about if bilateral?
10-15 deg extension, slight ulnar deviation.
If bilateral, other side in neutral.
What are the only 2 proven benefits to repair vs. accelerated rehab for achilles ruptures?
Better plantarflexion strength
Earlier return to work
What are the 3 risk factors for wound complications after achilles repair?
Female
Smoker
Steroid use
Rank CRPP, ORIF, RSA, HA for proximal humerus fractures in terms of highest (a) complications, and (b) revision rate
(a) CRPP, RSA, ORIF, HA
(b) ORIF, RSA/HA, CRPP
What are the 3 indications for ankle distraction arthroplasty?
Young patients with post-traumatic arthritis
Congruent joint
>20 degree arc of motion
How much distraction is needed in an ankle distraction arthroplasty?
5mm
What are the 2 predictors of failure in ankle distraction arthroplasty?
Female
<20 degree arc of motion
What’s the diagnosis if you see an athlete with pubic pain and widening/lysis of the symphysis on XR?
Chronic osteitis pubis (due to repetitive pull of the adductors and rectus abdominis on the pubic symphysis)
What’s the diagnosis if a patient presents with abdominal pain that radiates to the groin which is exacerbated by sport and relieved by rest?
Athletic pubalgia (“sports hernia” – tear in abdominal wall)
Which nerve should be neurolysed when doing a repair for athletic pubalgia?
Genital branch of genitofemoral nerve
What is the hip labrum innervated by?
Branches of obturator nerve and nerve to quadratus femoris
By how much (%) does the labrum increase intra-articular contact surface and volume? Without it, how much do femoroacetabular contact pressures increase by?
Surface: 22%
Volume: 33%
Contact pressures: 92%
Has there been any level I/II evidence of better outcomes for labral repair vs. debridement?
Yes, repair is better in females with FAI. However, a recent Philippon JBJS study showed no difference at 10 year follow-up
When are C. diff infections considered community-acquired vs. hospital-acquired?
Community: <48h after admission or >12 weeks after discharge
Hospital: >48h-4 weeks after admission
List 6 risk factors for acquiring C. diff
Age >65
Diabetes
Prolonged hospital admission
Revision surgery
Multiple antibiotic exposure (especially Clinda)
Bowel surgery
What’s the treatment for C. diff collitis (mild, moderate, severe, severe with elevated lactate, recurrence)?
Mild: PO Flagyl
Mod: PO Vanco
Severe: PO Vanco + IV Flagyl
Severe with lactate >5 or WBC >50: subtotal colectomy
Recurrence: Vanco, not Flagyl
What constitutes an acceptable reduction after ORIF of a distal radius?
Radial inclination >15
Volar tilt >15
Radial shortening <2mm
Articular incongruity <2mm
Sigmoid notch incongruity <2mm
Which ACL test has the best sensitivity and specificity?
Sensitivity: Lachman
Specificity: Pivot-shift under EUA
What’s the first pelvic apophysis to appear and when does it ossify?
What’s the last pelvic apophysis to appear and when does it ossify?
First: AIIS (4, 17)
Last: ASIS (17, 25)
What are 3 symptoms of lead toxicity after a retained bullet?
Cramping
Constipation
Seizures
When should you treat lead toxicity with chelation therapy?
Blood levels >0.45 μmol/L
List 6 general risk factors for HO
Male
Previous HO
Multiple surgeries
Closed head injury
Prolonged mechanical ventilation
DISH
In what situation is static progressive splinting used these days?
In patients with severe head injuries to prevent elbow and ankle equinus contractures (ICU)
What’s the average wear rate of HXL-UHMWPE?
At what annual wear rate do you get concerned for osteolysis?
Average: 0.02mm/y
Concern: 0.2mm/y
List 4 ways to measure wear in a THA
Linear wear
Volumetric wear
Dual circle technique
Radiostereometric analysis
How do you determine if a THA is “stable” intraoperatively?
Flexion >90
IR >45 with hip flexed to 90
ER >15 with hip extended
List 3 ways to test for malnourishment and their cutoffs
Albumin <35
WBC < 1.5
Transferrin <20
List 3 intraoperative considerations for obese patients undergoing a TKA
Reverse Trendelenburg is best for ventilation
Computer navigation
Stemmed tibial baseplate
Where is type I collagen found?
Bone, ligaments, sclerae, dentin
What are the spinal manifestations of patients with OI?
Basilar invagination
Scoliosis
Kyphosis
Spondylolisthesis
What are the 4 types of OI, their features and inheritance pattern?
I: mild (blue sclerae, fractures after walking age, mild scoliosis) – AD
II: deadly intra-uterine – AR/spontaneous
III: severe (fractures before walking age, spinal manifestations, dentinogenesis imperfecta, joint instability) – AR/spontaneous
IV: intermediate (less severe form of type III) – AD
What non-operative modality has been shown to reduce fracture rate and prevent scoliosis progression in OI?
Bisphosphonates (if started before age 6)
How do you treat scoliosis in OI?
Bracing doesn’t work; fuse when >45 degrees and consider cement augmentation through fenestrated screws at the most proximal and distal levels
How do you treat basilar invagination that doesn’t reduce with intraoperative traction?
Staged approach (trans-oral decompression followed by occiput-C2 posterior fusion usually 1 week later)
List 5 intraoperative considerations when managing any patient with OI
Difficult airway (large head, short neck)
Gentle transfer to table (fracture risk)
Avoid tourniquet use (fracture risk)
Avoid succinylcholine (can cause fasciculations = fracture risk)
Increased bleeding risk
What are 4 complications of a vascularized fibular transfer in pediatric patients with open physes?
Peroneal nerve injury
Claw toes (FHL)
Syndesmotic instability (consider doing a synostosis for distal harvests)
Ankle valgus deformity (from distal tibial growth arrest)
List 6 complications of halo gravity traction
Pin infection
Skull penetration (don’t use in patients <18 mo)
Cranial nerve VI palsy (lateral gaze)
Brachial plexus palsy
Odontoid AVN
SMA syndrome
Where is the humeral head center of rotation relative to the intramedullary canal?
5mm medial and posterior
What are the 4 red flags for back pain?
Night pain
Constant pain
B symptoms
Back pain in patients <10
What’s the Sorensen criteria for Scheueremann’s kyphosis?
> 5 degree anterior wedging at 3 adjacent levels
45 degree local kyphosis
What’s the typical fusion level in Scheuermann’s kyphosis? When is surgery indicated (4)?
T2-include first lordotic disc
Surgery when:
1. >75 degree kyphosis
2. Pain not managed adequately without surgery
3. Neurologic symptoms
4. Failed conservative treatment
What proportion of vertebral osteomyelitis shows (a) leukocytosis, (b) positive blood cultures, (c) organism identified on biopsy?
(a) half
(b) one third
(c) most
What are the surgical indications for FDP reconstruction?
- failed zone II repair
- supple joint
- no neurovascular injury
- disrupted FDS (can still do it if FDS is intact by releasing FDS insertion on the middle phalanx and repairing it end-to-end to the distal FDP stump, but some people recommend against it since an intact FDS still provides reasonable function).
Describe the general principles of a 2-stage Hunter procedure for a flexor tendon reconstruction
First stage: insert silicon rod in the flexor tendon sheath and reconstruct the pulleys as needed (A2 and A4 most importantly).
Second stage: 3 months later, remove silicon rod and insert tendon graft (palmaris, plantaris)
Describe the Seddon and Sunderland classification of nerve injuries and expected prognosis for each
I: Neurapraxia (full recovery, up to 2 months)
II: Axonotmesis with intact endoneurium (mostly full recovery, 2-4 months)
III: Axonotmesis with disrupted endoneurium (partial recovery, 12 months)
IV: Axonotmesis with disrupted endo- and perineurium and only epineurium intact (poor recovery)
V: Neurotmesis (no recovery)
What tendon transfer is used for a foot drop (peroneal palsy)?
PTT through IOM to the lateral cuneiform (4 incision technique)
List 5 risk factors for failure of bracing in AIS
Male
Suboptimal correction in-brace
Non-compliance
Obesity
Hypokyphotic thoracic curve
List 5 ways to determine appropriateness of humeral implant height
5.6 cm above upper border of pectoralis major
0.8 cm above GT
1 cm below lateral acromial edge
Anatomic reduction of the tuberosities
Measure resected head
Which 3 structures can block reduction of a medial subtalar dislocation? What about lateral?
Medial: EDB, deep peroneal bundle, TN capsule
Lateral: Tib post, but also FHL, FDL, posterior tibial bundle
Where are pediatric trigger fingers most commonly located? What % spontaneously resolve? What’s the treatment if conservative management fails?
Thumb.
50%.
A1 pulley release (if digit other than thumb is involved, A1 pulley release is not adequate since disease involved A3 pulley as well and has multiple nodules in the tendon).
What 5 endocrine abnormalities is polyostotic fibrous dysplasia associated with?
Hyperthyroidism
Hyperprolactinemia
Cushing’s
Hypophosphatemia
Acromegaly
List 5 extra-osseous manifestations of fibrous dysplasia (McCune-Albright and Mazabraud syndrome)
Hyperthyroidism, hyperparathyroidism, precocious puberty, cafe-au-lait spots (M-A syndrome) and intramuscular myxomas (Mazabraud)
What’s the difference between the cafe-au-lait sports in neurofibromatosis vs. McCune-Albright syndrome?
NF1: “coast of California” smooth appearance
M-AS: “cost of Maine” roughened appearance
What is the histological hallmark of fibrous dysplasia?
Inability to produce mature lamellar bone from immature woven bone with “alphabet soup” appearance
What can exacerbate fibrous dysplasia?
Pregnancy (increased number of hormones, and osteoblasts in FD have more hormone receptors)
When are bisphosphonates used in fibrous dysplasia
Polyostotic form
Which bone graft should you use in fibrous dysplasia?
Cortical or cancellous allograft (never autograft)
What are the zones of the physis?
- Trabecular bone zone
- Zone of provisional calcification
- Zone of hypertrophy (weakest)
- Zone of proliferation (entire growth depends on this)
- Resting zone
List 6 factors that can lead to reduced knee extension after ACLR
Cyclops lesion
Arthrofibrosis
Anterior tibial tunnel placement (notch impingement)
Graft tensioning in 30 degrees of flexion
Failed bucket handle meniscal repair
Delayed physiotherapy
List 4 structures that can contribute to a swan-neck deformity in patients with RA
- FDS rupture
- PIP volar plate rupture with dorsal subluxation of lateral bands
- Collateral extensor band rupture (mallet finger)
- Volar subluxation of MCP joint
List 4 malignant transformations of fibrous dysplasia
Osteosarcoma
Chondrosarcoma
MFH
Fibrosarcoma
What are 5 methods to diminish blood loss during spine surgery?
Permissive hypotension (aim for MAP 80)
Acute normovolemic hemodilution
Epidural blockade (vasoconstricts proximally)
TEXA
Electrocautery use
List 6 risk factors for non-therapeutic opioid use
Age <45
History of drug abuse
Family history of drug abuse
Smoker
Pre-operative opioid use
Mental illness
List 4 features of infantile scoliosis that suggests the deformity will progress
Mehta predictors of progression:
1. Cobb angle >20
2. RVAD >20
3. Phase 2 rib
4. Progression >6 degrees/year
What’s the feared complication in an infant with granulomatous vertebral osteomyelitis? What are 6 risk factors?
Buckling collapse (>120 degree kyphosis)
Risk factors:
1. Pre-treatment kyphosis >30 degrees
2. Junctional level
3. Gapping of facet joints
4. Retropulsion of infected vertebra
5. Lateral listhesis
6. Toppling
List 4 radiographic risk factors for progression of infantile Blount’s
Drennan angle >16
Epiphyseal distortion
Langenskiold IV-VI
Progressive varus
List 5 radiographic findings of femoral head AVN in DDH
Delayed development of ossific nucleus
Fragmentation of ossific nucleus
Lateral physeal irregularity
Metaphyseal widening
Varus neck with GT overgrowth
List 5 radiographic findings in pediatric rheumatoid spine
Apophyseal fusion (C2-3 usually)
Dens waist erosion (apple core deformity)
Atlantoaxial instability
Hypoplastic vertebral bodies
Loss of cervical lordosis
List 6 risk factors for non-union in type II odontoid fractures
Age >40
Gapping >1mm
Posterior displacement >5mm
Posterior re-displacement >2mm after start of treatment
Angulation >11 degrees
Comminution
List 4 seronegative spondyloarthropathies
Ankylosing spondylitis
Psoriatic arthritis
Reiter’s sydnrome
Inflammatory bowel disease-associated arthropathy
List 3 reasons to prophylactically pin the contralateral hip in SCFE
SCFE associated with endocrinopathy
Age <10
Obesity (>90%ile)
List 5 pediatric manifestations of Peyronie’s disease
Bent penile erections
Painful erections
Penile plaques
Penile numbness
Decreased penile rigidity
List 5 causes of lower extremity Charcot arthropathy other than diabetes
ETOH
Myelomeningocoele
Syrinx
Syphilis
Spinal cord injury
List 4 compliciations associated with BMP-2 use in spine surgery
Ectopic bone formation
Seroma
Post-operative radiculitis
Carcinogenic
List 3 strategies for safe tourniquet usage for surgeries that are expected to take longer than 2.5 hours
- Use wider cuff
- Let tourniquet down at 2h for 10 minutes, then 10 minute down-times at hourly intervals
- Inflate 75 mmHg >limb occlusion pressure
Does GA or spinal anesthetic have a higher complication rate in TKA, and list 4 complications?
GA (infection, pneumonia, AKI, mortality)
What nerves are blocked by an adductor canal block?
Saphenous
Obturator nerve branches
Medial retinacular branches
Nerve to vastus medialis (motor)
List 4 indications for debridement in isolation for shoulder OA?
Young laborer
Concentric joint
Small osteophytes
<2cm OCDs
List 3 predictors for requiring a THA following a hip arthroscopy?
Older age
<2mm joint space
Microfracture required
What’s a normal talocrural angle?
8-15 degrees (angle between a line perpendicular to the tibial plafond articular surface and a line connecting the malleoli)
What is PDGF approved for in Canada?
Hindfoot fusions
What is the risk of PGDF use?
Carcinogenic with topical form (not with rhPDGF that is used in foot and ankle fusions)
What is BMP approved for in Canada?
Lumbar fusions
Open tibia fractures
What do NSQIP databases measure? Is IRB required to analyse the data?
Pre-operative events
Post-operative events
Comborbidities
30-day morbidity and mortality
IRB is not required since patients are de-identified
What’s the initial non-operative treatment of a UCL injury?
Throwing cessation for 3 months
Elbow strengthening
Mechanics re-structuring
Graduated painless return-to-throwing program
List 5 risk factors for a pediatric VTE
Infection surgery
Hyponatremia
Hematologic disorder
Abnormal PTT
Elevated AST
List 4 downsides of minimalist running vs. shod running (heel-strike)
- Increased gastrosoleus injuries (eccentric contraction as forefoot or midfoot strike the ground)
- Increased base of metatarsal stress fractures
- Higher risk of puncture wounds
- Higher risk of plantar fasciitis
List 2 benefits of minimalist running vs. shod running
- Less patellofemoral pain
- Less joint reactive forces on the hip (center of gravity shifts more centrally)
List 6 negative prognostic factors in TTC nailing
Diabetes
PVD
Previous foot ulcerations
Smoker
Rheumatoid arthritis
Chronic steroid use
The _____ an extra-articular knee deformity is to the knee, the _____ the impact is on alignment
closer, greater
When can you manage an extra articular (a) femoral and (b) tibial deformity simply with soft-tissue balancing and not an extra-articular osteotomy?
Far from the joint line
<20 degree deformity in the femur
<30 degree deformity in the tibia
List 6 clinical features of ankylosing spondylitis
Bilateral sacroiliitis
Inflammatory back pain (>3 months)
Progressive kyphosis (chin-to-chest)
Anterior uveitis
Peripheral joint arthritis
Enthesopathy
How many levels above and below a fracture in ankylosing spondylitis should be included in the fusion?
3
List 2 complications specific to spine surgery in ankylosing spondylitis
Epidural hematoma
Aortic dissection
Which PCL bundle is largest and strongest?
Anterolateral
What’s the position of fusion for D2-5 MCPs and PIPs?
MCPs: start at 25 degrees for D2, then increase by 5
PIPs: start at 40 degrees for D2, then increase by 5
Describe the (a) incision and (b) fixation choice for MCP/PIP fusion
(a) curved incision (allows both MCPs and DIPs to be addressed if needed)
(b) crossed K-wires have a proven track-record
List 4 special considerations when nailing a femur fracture in a patient with OI
- Increased fracture risk
- Non-linear canal due to previous fracture healing
- Atypical femoral bowing (may need to do multiple osteotomies to pass the nail)
- Short limb (may need to use pediatric implants)
List 2 special considerations when performing a THA in a patient with OI
- Acetabular protrusio (may need to either bone graft and use screws vs. cup-cage)
- Cement the femur always
What’s the risk of femoral head AVN in hip dislocation if it was reduced within 6 hours and >6 hours?
<6h: 5%
>6h: 50%
What’s the definition of proximal junctional kyphosis?
> 10 degree Cobb angle and >10 degree change from pre-operative films at the top level of the fusion
List 6 risk factors for PJK
Combined approached
Fusion to sacrum (more rigidity but also worse curve)
Pedicle screws at all levels (increased rigidity)
>5 degree kyphosis at UIV preoperatively
High preoperative pelvic incidence (saggital imbalance)
Osteopenia
List 5 strategies to diminish the risk of PJK
Single approach without disruption of PLC at UIV
Hooks at UIV rather than screws (soft landing)
Strategic use of pedicle screws if all-screw construct
Instrument one level above UIV if >5 degree kyphosis
Osteotomies to correct saggital imbalance
List 5 factors associated with trunnion wear
Larger head
Increased offset
Varus neck
Dissimilar metals
Smaller, more flexible necks
What’s the optimal fixation for C1-C7?
C1: lateral mass screws
C2: pars or intra-laminar screws
C1-2: trans-articular screws (if C1-2 is reduced)
C3-6: lateral mass screws
C7: lateral mass/pedicle screws
List 3 risk factors for navicular stress fractures
Long 2nd metatarsal
Metatarsus adductus
Equinus contracture
What % of patients with chronic (>2 weeks) elbow dislocations will have HO?
75%
List 4 structures that are pathologic in a chronic elbow dislocation
Triceps contracture
Collateral contracture
Capsular contracture
Arthrofibrosis
What’s the best approach for dealing with a chronic elbow dislocation and why?
Medial and lateral paratricipital (Kocher interval extension laterally) since you can transpose the ulnar nerve which is often needed as well as release the collaterals to achieve reduction then repair them
List 3 indications for triceps lengthening in a chronic elbow dislocation
> 3 months
<100 degrees of flexion after other releases performed
5cm overlap between humerus and olecranon on AP
List 3 ways to achieve lengthening of the triceps
Triceps mobilization from distal humerus
Anconeus slide
Triceps V-Y lengthening
What are the 2 indications to perform a supramalleolar osteotomy?
- Asymmetric varus/vaglus deformity with >50% tibiotalar articular surface preserved
- To correct alignment for planned ankle arthrodesis/arthroplasty
List 5 contraindications to a SMO
Hindfoot instability
Age >70
Inflammatory arthritis
Charcot foot
Severe PVD
How can you determine if an ankle asymmetric varus/valgus deformity is originating from within the joint or outside?
If the difference between the *distal tibial plafond angle and **talar articular angle is >4 degrees, it means there’s an intra-articular deformity. If the total amount of varus/valgus deformity on the Saltzman hindfoot alignment view exceeds that value, then there’s also an extra-articular deformity.
*Distal tibial plafond angle is the angle between the anatomic axis of the tibia and the tibial plafond.
**Talar articular angle is the angle between the anatomic axis of the tibia and the talar dome.
Describe the principles behind a SMO for an extra-articular varus deformity (1. where it’s done; 2. what correction you aim for; 3. how you deal with the fibula)
- Medial opening wedge at the CORA for <15 degree correction; medial opening dome osteotomy at the CORA for >15 degree correction.
- Aim for 4 degrees of valgus at the level of the ankle joint (anatomical axis of the tibia to pass just lateral to the center of the ankle joint)
- Fibular osteotomy required if >10 degree correction.
What may need to be done if you’re doing an opening dome SMO for an extra-articular varus deformity?
Lengthening of posteromedial structures
Tarsal tunnel release
Describe the principles behind a SMO for an extra-articular valgus deformity (1. where it’s done; 2. what correction you aim for; 3. how you deal with the fibula)
- Medial closing wedge at the CORA for <15 degree correction; medial closing dome osteotomy at the CORA for >15 degree correction.
- Aim for 4 degrees of varus at the level of the ankle joint.
- Almost always requires a fibular osteotomy.
Which approach is used for a medial wedge vs. dome (opening or closing) osteotomy?
Wedge: medial approach
Dome: anterior approach
List 3 treatment strategies for prevention of PJK
Teriparatide (better than bisphosphonates)
Use hooks at UIV (soft landing)
Cement augmentation at UIV
List 8 risk factors for development of a pseudarthrosis after an attempted spine fusion
Uninstrumented fusion
Multilevel fusion
L5/S1 level
Smoker
Diabetes
Steroid use
NSAIDs
Bisphosphonates
Where’s the location of the anatomic femoral ACL tunnel?
8mm anterior to posterior articular margin
1.7mm proximal to the bifurcate ridge (ridge that divides the AM and PL bundles)
Describe the ossification of the clavicle
Lateral: intramembranous
Medial: endochondral
Is diaphyseal endosteal blood flow centripetal or centrifugal?
Centrifugal in adults (starts of centripetal in paeds)
Describe the course of the MFCx artery
Branch of profunda femoris (75%) or femoral artery proper (25%), runs between psoas and pectineus, then between obturator externus and adductor brevis, then it gives off ascending branch (femoral head), acetabular branch, transverse branch and posteroinferior branch.
What’s a donor artery option for vascularized fibular grafts?
Ascending branch of the LFCx
What two arteries are at risk in a Kocher-Langenbeck approach?
MFCx
Inferior gluteal (supplies GMax; emerges from GSN between piriformis and superior gemellus)
What’s the blood supply to the acetabulum?
Acetabular artery (branch of obturator – supplies the triradiate cartilage)
SGA
IGA
Ischial artery (branch of internal pudendal)
How much bone superior to the acetabulum should be left intact during a PAO to preserve the blood supply?
2-2.5cm
List 1 high-profile medical device failure
DePuy ASR metal-on-metal hip (4 x std revision rate)
List the 4 pertinent findings of the BRAIST trial (bracing vs. observation in AIS patients with 20-40 degree curves between Risser 0-2)
78% of braced didn’t progress past 50 degrees vs. 48%
NNT was 3 to avoid 1 surgery
>13 hrs/d was the threshold for a >90% success
No difference in QOL scores for bracing vs. observation
When is the Providence brace indicated?
TLSO used mostly for lumbar curves (per Dr. Smit)
When is the Rigo brace effective?
Most AIS curves (thee-dimensional curve correction) – can be worn during the day and night
What’s the goal of curve correction when the brace is applied?
About 50%
List 8 contra-indications to participation in strenuous physical activity after a C-spine fracture
Occipital-cervical fusion
C1 ring non-union
C1-2 residual instability
Subaxial instability
Loss of cervical lordosis
Pavlov ratio <0.8 (narrow canal from retropulsed frag.)
3 or more level arthrodesis
Neurological symptoms
What’s the most common site of metastasis in the hand?
Distal phalanges (thumb most commonly)
Where are hand enchondromas usually found?
Proximal phalanges
List 4 local treatment adjuncts after intralesional curettage in GCTs and enchondromas
Phenol
Dehydrated alcohol
PMMA
Liquid nitrogen (can cause skin burns, neuropraxia)
How does MSSA become MRSA?
It gains resistance to b-lactams via 4 types of staphylococcal cassette chromosomes, which allow for transfer of the mecA gene to S. aureus (types I-III cassette chromosomes are associated with hospital-acquired MRSA, while type IV is associated with community-acquired). The mecA gene encodes for a penicillin-binding protein that has a low affinity for b-lactams, hence resulting in resistance.
What are the most common bacteria in septic arthritis in patients <1, 1-5 and >5?
<1: Staph species, GBS
1-5: S. aureus, S. pneumo, Kingella Kingae, H. flu
>5: S aureus, N. ghonorrhea
What’s the Kocher criteria (including CRP)?
Fever
WBC >12
CRP >20
ESR >40
Refusal to weightbear
What’s the diagnostic criteria for juvenile idiopathic arthritis?
Fever >2 weeks
Effusion >6 weeks
25,000-100,000 cells on aspirate
<75% PMNs on aspirate
List 5 factors associated with successful closed reduction in DDH
Appropriate timing (<6 months)
Pre-reduction traction
Medial die pool <5mm
Adductor tenotomy
Maintenance of reduction on post-operative CT
What’s the safe zone for spica casting in DDH?
100 degrees flexion
<55 degrees abduction
How can you growth modulate a coxa valga?
Single screw inserted just below the GT aiming for the inferior 1/3 of the femoral head epiphysis
Define toughness
Area under the stress-strain curve
What’s the optimal % screw density for a bridge plate?
50%
Compared to patients <80 yo undergoing THA/TKA, what risks are patients >80 subject to?
3 x higher risk of MI, pneumonia and death. However, no correlation between ASA score and postoperative complications in this age group.
What’s the pedicle for a medial gastrocnemius flap?
Medial sural artery
Describe the posterior approach to the knee
- S-shaped incision over popliteal fossa (extend along LHBT proximally, and along semiT distally)
- Find medial sural cutaneous nerve, then incise deep fascia and follow it to the tibial nerve
- In the fossa, the tibial nerve is most superficial and the popliteal artery is the deepest
- Retract the bundle laterally off the capsule (may need to ligate superior medial and middle geniculates)
- Retract medial head of gastrocs medially (may need to release off the femur)
What’s the best flap?
1. small tibial tubercle/patellar tendon defect (anterior distal knee)
2. moderate patellar/suprapatellar defect (anterior proximal knee)
3. large suprapatellar defect
4. large, complex defect
- Medial gastrocs flap (medial sural artery)
- Vastus lateralis flap (descending branch of LFCx, lateral superior geniculate)
- ALT (anterolateral thigh) fasciocutaneous flap, which can be combined with a cuff of vastus lateralis (descending branch of LFCx, lateral superior geniculate)
- Latissimus dorsi free flap (donor = thoracodorsal; recipient = descending geniculate)
What’s the % risk of vascular compromise in a free flap?
20%
What’s an optimal cast index for distal radius fractures and how is it calculated?
<0.84 (internal width of the cast on the lateral XR/internal width of the cast on the AP at the level of the fracture)
List 5 indications for surgery in radius fractures in kids
Failure to achieve acceptable closed reduction
Loss of reduction at follow-up
Open fracture
Associated vascular injury or compartment syndrome
Floating elbow
Where is the entry point for a radius TEN?
Between 1st and 2nd extensor compartments proximal to the physis
What’s the difference in time to union, blood loss, time in hospital and early ROM in TENs vs. ORIF for BBFFs?
No difference in time to union, blood loss or admission time; ORIF however allows early ROM, no immobilization (TENs require 3-4 weeks in cast) and anatomic reduction.
What’s the most common site of facet joint cysts and what’s the pathophysiology?
L4-5 (DDD results in loss of disc height, which increases the stresses on the facet joints and add on to that L4-5 degenerative spondylolisthesis due to facet joint orientation at this level results in a stretched out facet joint capsule and cyst formation)
What’s the recurrence rate after surgery for a lumbar facet cyst?
<2% for decompression alone and 0% for decompression with fusion
What are the 3 patterns of congenital spinal stenosis?
- Short pedicles (decreased AP space)
- Flat laminae (decreases transverse spacpe)
- Global (combined)
What’s the best clinical outcome measure for lumbar spinal stenosis?
Oswestry Disability Index
What are the transfers for a wrist drop?
PL to EPL
FCR to EDC
Pronator teres to ECRB
Describe where the thumb UCL originates and inserts
Proximal-dorsal metacarpal to distal-volar proximal phalanx
What indicates a grade 3 UCL thumb tear?
Absolute laxity of >35 degrees or >15 degree laxity compared to the other side
List 2 indications for surgery in a Stener lesion
- Soft tissue Stener >3mm displaced
- Bony avulsion Stener
List 5 risk factors for patellar tendinosis
Fat
Flat foot
Frail quads
inFlexible quads
LLD
When doing the distraction method for pelvic discontinuity, when do you know you’ve reamed enough?
How much bigger should the acetabular component be than what you reamed?
Reamed enough when you have AS and PI contact.
6-8mm bigger.