Res Study Questions Flashcards
Reverse TSA vs Hemi, acutely for fracture - results of recent metaanalyses
comparable forward elevation, superior functional outcomes at expense of increased complication rtes and decreased shoulder rotation
benefit of rTSA vs Hemiarthorplasty for prox humerus fracture (acute)
forward elevation is INDEPENDENT of tuberosity healing, relies on deltoid m.
Active external rotation following rTSA for fracture relies on what?
Successful union of the greater tuberosity, incidence of tuberosity healing is higher and incidence of tuberosity resorption is lower in rTSA compared to hemiarthroplasty for fracture
What is the diagnosis
PVNS - synovial cell hyperplasia, hemosiderin laden macrophages
What patient population is most likely to develop PTSD following orthopaedic trauma
Females 4:1
Patients with a lower extremity fracture (including pelvis) 2:1
Multiple injuries DOES NOT increase risk of PTSD
What is the diagnosis?
Transient osteoporosis of the hip, treat with protected weightbearing
T1 - homogeneous low-intensity signal, T2-homogeneous high -intensity signal
What are the imaging findings in transient osteoporosis of the hip?
T1 - homogeneous low-intensity signal, T2-homogeneous high -intensity signal
What patient populations develop transient osteoporosis of the hip?
Middle aged men and pregnant women
Treatment for grade 1 hallux rigidus with NO pain midrange?
Cheilectomy
Outcomes of tibial inlay vs transtibial approach for PCL reconstruction
More graft protection during cyclical loading with the inlay approach
Indication for aTSA
endstage glenohumeral arthritis, INTACT rotator cuff
indications for rTSA
endstage glenohumeral arthritis DEFICIENT CUFF, comminuted proximal humerus fractures
indications for shoulder hemiarthroplasty
subacute presentations of 3-4 part fractures, or proximal humerus fracture dislocations, young patients with unipolar shoulder degeneration (eg avascular necrosis)
end result of scapholunate ligament injury
lunate extension, scaphoid flexion resulting in DISI (dorsal intercalated segment instability)
end result of lunotriquetral ligament disruption
Lunate flexion resulting in VISI
What is the most likely organism in peds septic joint with negative OR cultures?
Kingella kingae
COmpared to ORIF of an elderly intraarticular distal humerus, TEA results in?
improved function, with a trend toward a higher rate of major complications and reoperation after ORIF
Consequence of erronious disk space needle placement in spinal localization
3x increased risk of adjacent segment disease
When using a Grammont-style prosthesis for reverse total shoulder arthroplasty (RTSA), in which direction is the glenohumeral center of rotation shifted, compared with a native shoulder?
Medializing and distalizing the center of rotation tensions the deltoid and achieves a more constrained articulation, which allows the shear forces of shoulder abduction to be converted into a compressive force.
Volar intercalated segment instability - characteristic deformity, and ligament injured
volar lunotriquetral ligament -> dorsal radiotriquetral ligament -> volar radiolunate ligament. Lunate FLEXES (ie lunate tilts volar) forced by scaphoid while the triquetrum extends
Dorsal intercalated segment instability - characteristic deformity and ligament injured
Scapholunate interosseous ligament. Lunate EXTENDS (ie go dorsal)
Clenched fist syndrome
factitious disorder in which a patient presents with flexion contractures of the hand without an organic etiology. It often presents after a minor trauma or surgery. Surgical procedures initially are not indicated. Aggressive rehabilitative treatment accompanied by psychiatric support is necessary to facilitate improvement.
In regard to PIP arthroplasty - what implant and joint replacement approach combination has been demonstrated to have the lowest rate of revision surgery?
Silicone arthroplasty through a volar approach showed the greatest gains in arc of motion and had the lowest rate of revision surgeries. The rates of revision surgeries from low to high for each type of arthroplasty were 6% for silicone volar, 10% for silicone lateral, 11% for silicone dorsal, 18% for surface replacement dorsal, and 37% for surface replacement volar
Maximum number of days after collagenase injection that you can perform a successful manipulation
7
In a radioscapholunate fusion what effect does excising the distal pole of the scaphoid have?
Decreases the non-union rate.
preserving the midcarpal joint allows dart-thrower motion to remain, nd excising the distal pole increased radial and ulnar deviation
What ligament must be preserved in proximal row carpectomy or scaphoidectomy with four corner fusion?
Radioscaphocapitate
Compromise of the ligament would result in ulnar translocation of the carpus and early failure of the proximal row carpectomy procedure
Closed reduction of this injury is likely to be unsuccessful because
proximal phalanx head is buttonholed between the lateral band and central slip
Rotatory volar proximal interphalangeal (PIP) joint dislocations are uncommon but are more frequently irreducible than dorsal or lateral dislocations. The condyle of the proximal phalanx subluxates between the lateral band and central slip, and attempts at closed reduction tighten this area and are unsuccessful.
Closed reduction was performed, resulting in a stable concentric reduction that was confirmed with imaging. What is the best next step?
Splint in PRONATION
In the normal anatomic relationship between the distal radius and distal ulna, the distal ulna translates dorsally within the sigmoid notch during pronation. The distal ulna assumes a position along the volar aspect of the sigmoid notch when the forearm is in supination. When a closed reduction of a volar DRUJ dislocation is achieved, casting the forearm in relative pronation helps to maintain the reduction.
A patient with absent bilateral clavicles and bilateral coxa vara is consistent with what genetic syndrome?
cleidocranial dysplasia, RUNX2/CBFA1 Gene
A patient with absent bilateral clavicles and bilateral coxa vara has what type of cell is most affected by the genetic mutation causing this patient’s disorder?
Osteoblasts
Treatment for pediatric C1-2 rotatory instability involves:
if less than one week duration: NSAIDs and soft collar
>1 week but <1 month: cervical traction and hard collar immobilization
>=1 mmonth: cervical traction and halo vest application
C1-2 fusion if non-reducible, recurrent or chronic deformity
Often occurs in healthy children after a viral illness/URI
Complication of the chopart amputation and surgical option for prevention
Equinus contracture due to unopposed pull of the gastroc/soleus, prevent this by doing a posterior tibialis tendon transfer to the anterior talus
Following joint arthroplasty using conventional polyethylene as one of the bearings, what local factor is released by macrophages, leading to the activation of osteoclasts and eventual bone resorption?
TNF-alpha
Following joint arthroplasty, particulate debris can be generated from the polyethylene. These particles are typically engulfed by local macrophages, resulting in activation of the osteolytic cascade. The macrophages release TNF-alpha, which activates the osteoclasts that trigger resorption around the implants.
Treatment for Gymnasts wrist
activity modification and metabolic workup (Specifically Vitamin D levels). Casting is not often necessary as splinting and activity modification x 6 weeks alleviates symptoms
Motor innervation for Lumbar nerve roots
L2: iliopsoas/hip flexion
L3: Quadriceps/knee extension
L4: Tibialis anterior/ankle dorsiflexion
L5: EHL/great toe extension
S1: gastroc/soleus/plantarflexion
Sensory innervation for lumbar nerve roots
L3: medial thigh
L4: anterolateral thigh, medial calf
L5: anterolateral calf
S1: lateral foot
Following closed elbow dislocation, splint in pronation if:
medial collateral ligament [MCL] is intact and the lateral collateral ligament [LCL] is disrupted
Following closed elbow dislocation, splint in supination if:
Lateral collateral ligament [LCL] is intact, but the medial collateral ligament [MCL] is disrupted
Normal Acetabular index and alpha angle in developmental dysplasia of the hip
Normal Acetabular index: <25degrees in patients >6mo
Normal Alpha Angle: >60degrees
How many zone of articular cartilage cells are there?
Four:
Superficial zone: chondrocytes are elongated and collagen fibers are oriented parallel to the articular surface
Middle zone/transitional zone: chondrocytes and collagen fibers are oriented randomly
Deep Zone: chondrocytes are arranged in columns, and collagen fibers are oriented vertical to the articular cartilage.
Calcified zone: the transitional zone between the cartilage and the subchondral bone.
Structure at risk with anterior to posterior interlock screw placement in a humeral nail?
LABC (musclocutaneous nerve lies in interval between biceps/brachialis and you have to dissect this to do the A->P screw
IF the nail is malrotated and the trajectory is more anteromedial to posterolateral-> then the median nerve is at risk
Structure at risk with lateral to medial distal humeral nail interlock placment
Radial N
What type of specialty culture medium should be ordered if mycobacterium marinum is suspected?
Lowenstein-Jensen Media at 30 degrees
What type of specialty culture medium should be ordered if mycobacterium tuberculosis is suspected?
Lowenstein-Jensen Media at 37 degrees
What type of specialty medium should be ordered if Neisseria gonorrhea is suspected?
Thayer Martin medium at 37 degrees
The most common brachial plexus injuries involve which segments?
C5-6 - classic Erb palsy - deltoid and bicep palsy, intact wrist flexors/extensors
Next most common is C5-7 - deltoid, bicep, wrist and finger extensor palsy. Intact wrist/finger flexors
C5-T1 is complete brachial plexus palsy and is rare
What antibiotic coverage is used specifically for brackish water coverage?
Tetracycline plus third generation cephalosporin.
Brackish water = combination of fresha nd salt water that can harbor Vibrio species, Aeromonas hydrophila, Pseudomonas species, Erysipelothrix rhusiopathiae, and Mycobacterium marinum
Third gen cephalosporins - cefdinir, cefditoren, cefixime, cefotaxime, defpodoxime, ceftazidime, ceftibuten, ceftriaxone
Properties of bone graft
Osteogenic: material directly provides cells that will produce bone - eg MSCs, osteoblasts, osteocytes
OsteoINductive: material contains FACTORS that will stimulate bone growth (eg BMPs)
OsteoCONductive: material acts as a scaffold/structural framework for bone growth
What acetabular fracture pattern is associated with the highest incidence of nerve injury>
Transverse, posterior wall combined type acetabular fractures (30%)
What culture medium should be used if Kingella Kingae is suspected?
Blood agar
Which genetic pathway is responsible for normal development of the hindfoot and may play a role in development of idiopathic clubfoot?
PITX1-TBX4
Indications for forequarter amputation for chondrosarcoma
- (absolute) encasement of the vascular bundle
- (Relative) if the median or ulnar nerve is expected to be transected
- (relative) pathologic fracture
- resection of the axillary, musculocutaneous or radial nerves is NOT an indication for forequarter amputation
Genetic etiology of fibrous dysplasia
Galpha subunit of stimulatory G protein. Leads to constituitively active adenylate cyclase and increased cyclic adenosine monophosphate formation
Genetic mutation associated with achondroplasia
FGFR3
Genetic mutation associated with psuedoachondroplsia
COMP
Genetic mutation associated with Multiple hereditary exostosis
EXT1
What is the deforming force in madelung’s deformity?
Abberant ligament (Vicker’s Ligament) tethering the lunate to the volar ulnar corner of the radius causing growth slowing in that area of the radius
risk of recurrent patellar instability following a first time dislocation?
somewhere between 15-60% -> therefore treat non-operatively after the first dislocation (if no chondral loose body)
What type of acetabular osteotomy should be used in ambulatory CP patients?
A posterior coverage osteotomy.
In ambulatory (GMFCS I-III patients) the acetabulum is deficient posterior superior.
A salter osteotomy increases anterior coverage at the expense of posterior coverage, thus is not indicated. A Periacetabular osteotomy can increase posterolateral coverage but is NOT indicated in skeletally immature patients
What increases joint reactive forces in total hip arthroplasty?
Lateralization of the acetabular components, lateral/offset liners
Number needed to treat
1/Absolute risk reduction
What view is best for evaluating early anterior hip arthritic changes?
False profile view
What view is best for evaluating the anterosuperior femoral head-neck junction for cam lesions?
Dunn lateral
What type of congenital scoliosis is least likely to progress?
Block vertebra (Bilateral bars) and wedge vertebra. both at 2degrees per year
Hemivertebrae and unilateral bars progress between 2-6 degrees per year
Unilateral bars with contralateral hemivertebrae progress rapidly, between 5-10 degrees/yr
Describe the gluteus medius insertion on the femur
Attaches along the superoposterior and lateral facets of the GT with a bald area between the gluteus medius and gluteus minimus
In high energy, young femoral neck fractures, where is the comminution located?
Posterior and inferior
What is the most common pathogen for SOFT tissue infection of the foot caused by puncture wound
Staph or strep
What is the most common pathogen for OSTEOMYELITIS of the foot caused by a puncture wound?
Pseudomonas
Dystrophic vs non-dystrophic scoliosis
dystrophic scoliosis is characterized by a sharp angular curve involving 4 to 6 vertebrae. It is progressive and difficult to treat
NF 2 is not associated with scoliosis
What are the criteria for obtaining MRI of the hip prior to I&D
at least three of the following:
Age >4 years
CRP >13.8 mg/L
Duration of symptoms >3 days
Platelets <314x103 cells/uL
ANC >8.6x103 cells/uL
Normal Gait cycle leads to forces going through the hip joint equivalent to ______ times body weight
2-4 times body weight
Valgus knee restraints at full extension, 60 degrees of flexion, and full flexion
In full extenstion, the posterior oblique ligament is responsible for valgus restraint, superficial MCL is responsible for valgus restraint at full flexion, and Deep MCL has a small contribution to valgus restraint at 60 degrees of flexion but plays a more crucial role in preventing anterior translation of the knee
What is the role of the posterior tibial tendon during gait?
Invert the heel and lock the transverse tarsal joint to create a stiff lever with which to initiate heel raise
” posterior tibial tendon functions during the stance phase by adducting the transverse tarsal joint (Chopart joint). This leads to inversion of the subtalar joint. Once the heel is inverted, the foot stiffens and can support the propulsive phase of gait.”
What hormone has chondroprotective and chondroregenerative effects in vivo?
Parathyroid hormone
Where can you find the radial nerve in the posterior approach to the humerus?
- 14-15 cm proximal to the lateral epicodyle
- 20-21 cm proximal to the medial epicondyle
- OR new method: 4cm proximal to the triceps aponeurosis
How does biofilm allow for antibiotic resistance?
- by establishing an extracellular protein matrix that serves as a barrier limiting concentration of antimicrobial agents
- create an area low in nutrients, thus triggering a stress response in the bacteria and causing low metabolic activity. This can limit the effectiveness of certain antibiotics that target replicative machinery.
- Persister cells are a subset of cells within a bacterial population that are resistant to increased concentrations of antimicrobial agents. These cells have been identified in both planktonic and biofilm states. In the planktonic state, they can be destroyed by the innate immune system. In the biofilm state, they are protected from the innate immune system and can repopulate the bacterial biofilm if it is destroyed
- ability of a bacterial biofilm to disable the innate immune response. This is done by the release of factors such as alpha-toxin and leukocidin AB-induced macrophage dysfunction which inhibits phagocytosis
What is the most common reason for reoperation after corrective surgery for adult spinal deformity?
Pseudarthrosis, then proximal junctional kyphosis
What is the genetic inheritance patterns of congenital scoliosis?
Sporadic - in a family with an affected child the risk of having another affected child is <1%. Congenital scoli thought to be a vascular or other insult occurring at week 4-8 of gestation causing failure of segmentation or formation
What radiographic view of the distal humerus provides the most accurate representation of the true displacement of a medial epicondyle fracture?
Axial
What radiographic view of the distal humerus provides the most accurate representation of the true displacement of a lateral epicondyle fracture?
Internal oblique view
What is the rate of initial presentation of MRSA colonization amongst trauma center fracture patients?
3.2-3.4%
Most common injury for a victim of intimate partner violence?
Nasal bone fracture is most common. The other head, neck, or facial injuries
Factors associated with recurrence of ABC
youn age, open physis, incomplete initial curettage, higher stage, periarticular location
How do leptin levels and rates of hypertension compare in scfe patient compared with obese controls?
Increased leptin, increased rates of hypertension
elevated leptin levels had an increased odds ratio of 4.9 of having SCFE regardless of obesity status, sex, and race. Taussig et al compared children with SCFE and tibia vara with age-matched and sex-matched obesity clinic controls and found 2.5-fold higher odds of high blood pressure in the SCFE and tibia vara patients
Which statement best describes the Insall-Salvati index, which is used to assess patellar height?
Ratio of patellar tendon length to patellar length, and it normally measures <1.2
Which statement best describes the modified Insall-Salvati index, which is used to assess patellar height?
patellar height as a ratio of patellar tendon length (from tubercle to inferior patellar articular margin) to patellar articular surface length, and it normally measures <2.0
Which statement best describes the Caton-Deschamps index, which is used to assess patellar height?
ratio of inferior patellar articular surface distance from the plateau to patellar articular surface length, and it normally measures <1.3
What other clinical condition is Blount disease associated with?
Hypertension
What is the most common deformity after ACL reconstruction in a skeletally immature patient?
Valgus deformity from the distal lateral physis.
What is the standard three drug regimen for osteosarcoma?
doxorubicin, cisplatin, and high-dose methotrexate
The use of three drugs has been shown to result in better outcomes than the use of single or dual agents
What is the ADI cutoff/indication for surgical intervention in a patient with down syndrome and documented increased ADI
ADI (In down syndrome) >10 - surgery
ADI 4.5-10: likely represents hypermobility rather than instability - these children may participate in athletics, but should avoid high risk activities like diving and football
Patients who undergo corticosteroid injections 2 months prior to rotator cuff repair are more likely to have what complication?
Increased revision repair rate
describe the neuroanatomy in elbow arthroscopy portals and what nerves are at risk with each
- Proximal anteromedial portal: Medial antebrachial cutaneous nerve (1 mm), median nerve (12 mm), and ulnar nerve (7 mm but posterior to septum)
- Anteromedial (direct medial) portal: Medial antebrachial cutaneous nerve (1 mm) and median nerve (7 mm)
- Proximal anterolateral portal: Radial nerve (10 mm) and posterior antebrachial cutaneous nerve (0 to 14 mm)
- Anterolateral portal: Posterior interosseous nerve (2 to 10 mm) and posterior antebrachial cutaneous nerve (0 to 20 mm)
- Proximal posterolateral portal: Medial and posterior antebrachial cutaneous nerves (more than 2 cm)
Compared with synovial sarcoma, myxoid liposarcoma demonstrates increased rates of what?
Bony metastasis. Very. high rate of local control with radiotherapy and surgery
Synovial sarcoma has SYT-SSX fusion transcript and a higher rate of regional lymph node metastases
Describe the Wartenberg sign
persistent small finger abduction and extension during attempted adduction - caused by unopposed action of the ulnar insertion of the extensor digiti quinti (radial nerve innervation)
Weakness in what muscle is responsible for a positive Wartenberg sign in ulnar neuropathy
Third palmar interosseous and small finger lumbrical
In a child with a spine fracture, what is the incidence of concurrent spinal injury to another vertebral segment?
30-55%. 6% are non-contiguous (>3 levels away)
What syndrome/disease does this 2 week old have?
This patient has Caffey disease, or infantile cortical hyperostosis.
It is a self-limiting disorder characterized by acute edema and inflammation of the soft tissues and thickening of the bone secondary to increased periosteal bone formation.
There is usually spontaneous regression of the findings by 2 years of age; however, at presentation the child may initially appear to have osteomyelitis based on the elevated inflammatory markers and clinical edema.
The mandible is involved in 70 to 90% of cases followed by the clavicle, ribs, and scapulae.
Define the deforming forces in erb’s palsy that lead to contractures
weakness of the infraspinatus and teres minor and unopposed action of the internal rotators (dual innervation thus unaffected)
What is the role of coagulase in MRSA infections?
Coagulase, a Staphylococcus aureus virulence factor, activates prothrombin to thrombin, which leads to the cleavage of fibrinogen to fibrin. This promotes clot and abscess formation
What is the role of Von Willebrand factor binding protein in infection?
activates platelets and promotes adhesion of bacteria to blood vessel walls. This allows for tissue invasion and hematogenous spread of infection.
What is the role of clumping factors A and B in infection?
allow the bacteria to remain tethered to fibrin, preventing phagocytosis
What is the role of Panton-Valentine leukocidin in infection?
causes neutrophil degradation/lysis through pore formation at the cell’s surface.
What is the risk of malignant transformation in Ollier’s disease
Ollier’s disease is multiple enchondromatosis - and the risk of malignant transformation is 10-30%
Jaffe-Capanacci syndrome is characterized by what features?
cafe au lait spots and multiple non-ossifying fibromas (bony lesions are similar in radiographic appearance to enchondromas but skin features are unique)
What are the midterm functional outcomes of operatively treated patellar fractures?
52% rate of hardware removal and pain in 38% of those who kept their hardware. 20% of patient shad extensor lag, and 38% had restricted flexion. Extension power was also reduced compared to contralateral side.
What is the malignant transformation rate of solitary enchondromas?
1%, and occurs more commonly with sessile (“stuck-on”) lesions, as opposed to pedunculated lesions, and is more common in pelvic lesions than other anatomic locations
What is the malignant transformation rate of multiple enchondromas?
25-30% in multiple hereditary exostosis
When is a interosseous ligament reconstruction indicated?
When the radial head is resected rather than fixed or replaced
Otherwise a DRUJ stabilization is indicated
What ligaments comprise the hip ligament complex?
Iliofemoral (strongest of the three - inverted Y shape), pubofemoral, and ischiofemoral.
What is the rate of popliteal artery and peroneal nerve injuries in traumatic knee dislocations?
Popliteal artery injuries occur approximately 16% of the time, with subsequent amputation rate of 20%
Peroneal nerve injuries occur 25% of the time with a 50% recovery rate
What is the strongest predictor of femoral head osteonecrosis in SSD?
ratio of hemoglobin to hematocrit, second most useful: systolic blood pressure
Mutations of fibrillin in marfans syndrome leads to an over expressio of what factor?
TGFB
Order of ossification of the carpals
capitate: 1 to 3 months, hamate: 2 to 4 months, triquetrum: 2 to 3 years, lunate: 2 to 4 years, scaphoid: 4 to 6 years, trapezium: 4 to 6 years, trapezoid: 4 to 6 years, and pisiform: 8 to 12 years.
In lesch-nyhan syndrome, what will laboratory evaluation demonstrate?
Increased serum uric acid
Two week old male with the following radiographs, no evidence of NAT, Laboratory studies show elevation of erythrocyte sedimentation rate, serum alkaline phosphatase level, and serum C-reactive protein level. What is the diagnosis? And what bone involvement is pathognomonic?
Caffey disease, or infantile cortical hyperostosis. It is a self-limiting disorder characterized by acute edema and inflammation of the soft tissues and thickening of the bone secondary to increased periosteal bone formation. There is usually spontaneous regression of the findings by 2 years of age; however, at presentation the child may initially appear to have osteomyelitis based on the elevated inflammatory markers and clinical edema. The mandible is involved in 70 to 90% of cases followed by the clavicle, ribs, and scapulae
