missed

Question 1

what is Kim lesion

Answer 1

reverse bankart, posterior inferior labral injury

test with a jerk test

Question 2

specificity equation

Answer 2

TN/(TN+FP)

Question 3

Postoperative radiculopathy is a known complication of posterior cervical decompression for myelopathy. One potential mechanism of nerve root injury is thought to be tethering of the nerve root with dorsal migration of the spinal cord. What is the most common radicular pattern seen with this condition?

Answer 3

motor dominant with weakness of the deltoid

Question 4

Which of the following zones has been shown to contain articular cartilage progenitor cells

Answer 4

superficial tangential zone (surface)

Question 5

what is injured in an eversion injury

Answer 5

often anterior colliculus of the medial Mal

Question 6

treatment of bad bunion in CP kid

Answer 6

fusion (first MTP), other kids get osteotomy

Question 7

worst place to put your screw for SCFE

Answer 7

anterior superior quadrant

Question 8

treatment of osteochondritis dissicans if stable lesion

Answer 8

return to play when asymptomatic after 6 weeks rest

Question 9

mechanism of injury for TFCC

Answer 9

wrist extension and forearm pronation. occurs in athletes when falling

Question 10

ligaments injured in Type 5 AC joint injury

Answer 10

AC and CC (for type 3 and up)

Question 11

salvage osteotomy

Answer 11

chiari and shelf

Question 12

internal impingement is caused by what

Answer 12

impingement of the humeral head and the glenoid

Question 13

best way to cement TKA

Answer 13

around base and keel

Question 14

How are free radicals removed from highly cross-linked polyethylene

Answer 14

thermal processing

Question 15

eden lange procedure

Answer 15

The muscle transfer procedure most commonly performed for trapezius paralysis is the Eden-Lange procedure. Trapezius paralysis in this patient is secondary to iatrogenic injury to the spinal accessory nerve during lymph node biopsy. In this procedure, the levator scapulae and rhomboid minor and major muscles are transferred laterally. Pectoralis transfer to the inferior border of the scapula is used as a dynamic transfer for serratus anterior winging.

Question 16

Compared to metal-on-polyethylene total hip bearing surfaces, the debris particles generated by metal-on-metal articulations are

Answer 16

smaller and more numerous

Question 17

Beckwith-Wiedemann syndrome

Answer 17

exophthalmos, macroglossia, gigantism, visceromegaly, abdominal wall defects, and neonatal hypoglycemia. Hemihypertrophy develops in approximately 15% of patients with BWS. Patients with hemihypertrophy that is the result of BWS have a 40% chance of developing malignancies such as Wilms’ tumor or hepatoblastoma; therefore, frequent ultrasound screening is recommended until about age 7 years. The absence of nevi and vascular markings helps to rule out other causes of hemihypertrophy, such as neurofibromatosis, Proteus syndrome, and Klippel-Trenaunay syndrome. Bone age estimations are not accurate at this young age but may become more useful later to help predict the timing of epiphysiodesis procedures.

Question 18

primary mechanism of polyethylene wear in the hip

Answer 18

adhesion/abrasion

Question 19

Premature arrest following growth plate injury is attributed to what mechanism?

Answer 19

vascular invasion across the physis

Question 20

how does ETO affect strength of femur

Answer 20

the approach used reduces the torque-to-failure (fracture) of the construct to less than 50% of the intact femur.

Question 21

To control most spontaneous bleeding into the knee in children with hemophilia, factor VIII must be replaced to what percentage of normal?

Answer 21

The knee is the most common location of spontaneous bleeding in children with hemophilia. Treatment generally requires replacement to 40% to 50% of normal. For surgery, the replacement should be to 100%. The plasma level generally rises 2% for every unit (per kg body weight) of factor VIII administered.

Question 22

Hypersensitivity to metal implants is usually classified as what type of Gell-Coombs reaction?

Answer 22

type 4

Question 23

infection after varicella

Answer 23

group a strep

Question 24

What is the most important sign of impending modulation with rapid progression of a spinal deformity in neurofibromatosis

Answer 24

Rib penciling is the only singular factor; 87% of the curves progressed significantly in patients with three or more penciled ribs. Modulation in neurofibromatosis scoliosis implies the change from an idiopathic type to a dysplastic type of curve with rapid progression and the need for aggressive stabilization by fusion.

Question 25

contraindication to HTO

Answer 25

Contraindications to HTO include inflammatory arthritis, degenerative changes in the lateral and/or patellofemoral compartments, range of motion of less than 90 degrees, flexion contracture of greater than 15 degrees, and ligamentous instability.

Question 26

What are the 2 anterior cruciate ligament (ACL) bundles and their respective functions?

Answer 26

Anteromedial that tightens with knee flexion; posterolateral that tightens with knee extension

Question 27

The primary action of 1,25(OH)2 vitamin D is to increase

Answer 27

When serum calcium levels are low, parathyroid hormone is used to stimulate the conversion of 25(OH) vitamin D to 1,25(OH)2 vitamin D, which is its active form. Its primary mechanism of action is to increase intestinal absorption of calcium.

Question 28

All of the following are true regarding osteocalcin EXCEPT which of the following?
It is the most prevalent non-collagenous protein in bone
2
It is expressed by mature osteoblasts
3
It is considered a marker for osteoblast differentiation
4
It is a glycoprotein that binds calcium
5
Higher levels are correlated with increases in bone mineral density during osteoporosis treatment

Answer 28

4.Pure fact question from basic science. “Osteocalcin is the most prevalent noncollagenous protein in bone” (from Miller’s Review). It is expressed by mature osteoblasts and is a marker of osteoblast differentiation. Osteocalcin is the most specific marker of the osteoblast phenotype and is expressed only in mature osteoblasts. During osteoporosis treatment, serum levels correlate with increases in bone mineral density. Osteonectin, not osteocalcin, is a glycoprotein that binds calcium.

Question 29

Cervical facet dislocations are characteristically caused by which of the following mechanisms of injury?

Answer 29

flexion distraction

Question 30

mechanism for superior retinaculum tear for peroneal tendons

Answer 30

dorsiflexion, eversion

Question 31

A 78 year-old male has been having progressive pain in his left thigh and hip when walking. He is otherwise healthy and takes no medications. Laboratory evaluation reveals normal ESR and CRP, but elevated urinary hydroxyproline and increased urinary N- and alpha-C-telopeptides. what disease

Answer 31

pagets, with 1% risk transformation to osteosarcoma

Question 32

characterized by excessive bone resorption and disordered bone formation

Answer 32

Paget’s disease is characterized by excessive bone resorption and disordered bone formation.

Paget’s disease of bone is seen in older patients of Anglo-Saxon descent, and is frequently asymptomatic. It progresses through three radiographic phases: lytic, mixed, sclerotic. During the lytic phase there is excessive osteoclast activity. This is followed by increased bone formation, though the bone is woven and disordered. Treatment is with bisphosphonates to block osteoclast activity. Paget’s has a strong autosomal dominant genetic tendency with the candidate gene 5q35-QTER, and may be caused by a slow viral infection (PMV, RSV). Malignant degeneration occurs <1% of the time.

Question 33

What is the cellular mechanism of action for non-nitrogen containing bisphosphonates (such as clodronate and etidronate) to induce osteoclast apoptosis?

Answer 33

Bisphosphonates work by one of two mechanisms. Non-nitrogren containing bisphosphonates (such as etidronate and clodronate) work by creating a toxic analog of ATP which inhibits ATP and leads to osteoclast apoptosis. Nitrogen containing bisphosphonates (such as alendronate, risedronate, and zoledronate) inhibit the enzyme farnesyl diphosphate synthase which prevents protein geranylgeranylation and prevents osteoclastic bone resorption.

Question 34

Which immunoglobulin subtype does the rheumatoid factor target

Answer 34

IGG
Rheumatoid factor is an auto-antibody most commonly seen with rheumatoid arthritis. The presence of rheumatoid factor can also indicate generalized autoimmune activity unrelated to rheumatoid arthritis (e.g. tissue or organ rejection). Rheumatoid factor is itself an IgM antibody that is directed against the Fc portion of IgG antibody. Rheumatoid factor (IgM) attaches to IgG to form immune complexes which are deposited in tissues like the kidney and contribute to the overall disease process in rheumatoid arthritis.

Question 35

Which of the following bone modulators primarily utilizes adenylyl cyclase as a mediator for its cellular signaling within osteocytes?

Answer 35

Parathyroid hormone receptor activation primarily stimulates the pathway involving adenylyl cyclase/G-alpha stimulatory protein/cAMP/protein kinase A in osteocytes. BMPs target undifferentiated mesenchymal cells and signal through serine/threonine kinase receptors. Intracellular molecules called SMADs act as signaling mediators for BMPs. IGF-II stimulates type I collagen, cartilage matrix production, and bone formation. IGF-II signals through tyrosine kinase receptors primarily. Transforming growth factor-Beta (TGF-ß) stimulates osteoblasts to synthesize collagen and primarily signal through serine/threonine kinase receptors.

Question 36

What nerve is injured most

Answer 36

LABC

Question 37

ACL biomechanics

Answer 37

The ACL has the biomechanical properties of viscoelasticity, creep, stress relaxation, and nonlinear elasticity. It does NOT demonstrate isotropism. Isotropic materials such as metals exhibit the same mechanical properties in all directions.

Question 38

Which of the following risk factors is felt to contribute greatest to the higher rate of ACL rupture in female compared to male athletes?

Answer 38

neuromuscular factors

Question 39

when does DNA replication occur

Answer 39

The cell cycle consists of four distinct phases: initial growth (G1), DNA replication/synthesis (S), a gap (G2), and mitosis (M) (see illustration).

Question 40

Following ACL reconstruction, which of the following tests most closely correlates with patient satisfaction with their reconstructed knee

Answer 40

pivot shift

The pivot-shift examination may be a better measure of “functional instability” than instrumented knee laxity or Lachman examination following anterior cruciate ligament reconstruction.

Question 41

A 7-year-old recent immigrant presents with pain and tenderness over the legs. Physical exam shows the gums have a bluish-purple hue with areas of hemorrhages. A radiograph is shown in Figure A. In Figure B, what region of the growth plate is most affected in this condition

Answer 41

The clinical presentation and radiographs are consistent with scurvy. The radiographs show a dense band (White line of Frankl) at the growing metaphyseal end which is characteristic of scurvy. Scurvy is a disease resulting from a deficiency of vitamin C (ascorbic acid), which is required for the synthesis of collagen in humans. Impaired collagen synthesis in scurvy leads to fragile capillaries, resulting in abnormal bleeding, and altered bone formation at the growth plate. More specifically, scurvy affects the spongiosa the most (but not exclusively) in the metaphysis,

Question 42

patient with ankylosing spondylitis and a hip flexion contracture undergoes uneventful right total hip replacement using a Kocher (posterior) approach. This patient is at increased risk for which of the following complications post-operative

Answer 42

anterior hip dislocation

Degenerative joint disease due ankylosing spondylitis (AS) with a concomitant hip flexion contracture increases post-operative rates of anterior hip dislocations. Correction of hip flexion contracture with THA can restore sagittal balance. However, when positioning the acetabular component in a patient with AS, one must account for the relationship of the pelvis to the lumbar spine in the sagittal plane in order to avoid an excessively hyperextended hip once the patient resumes an upright position.

Tang el al followed 95 primary THA’s in patients with AS for over 10 years. Their series had 3 dislocations, 2 of which were anterior. They noted that, because of the presence of relative hyperextension of the hips after THA, AS patients are more prone to anterior dislocation when acetabular components are placed in their normal position relative to the pelvis.

In a more recent study, Bhan et al retrospectively reviewed 54 patients (92 hips) who underwent cementless total hip arthroplasty for bony ankylosis in AS via a posterior surgical approach. At an average of 8.5 years follow-up, they noted that anterior dislocation occurred in 4 (4.3%) of the hips and that there were no posterior dislocations.

Question 43

In the adult spine, which of the following pedicles have the smallest average transverse diameter.

Answer 43

Knowledge of pedicle diameter is important when placing pedicle screws. On average, thoracic pedicle diameter is maximal at T1 and T12, and gradually “dips” to its smallest diameter at the T4 to T6 region.

Question 44

A 28-year-old professional baseball pitcher sustains a complete rupture of his ulnar collateral ligament. He is neurovascularly intact on exam. Which of the following surgical reconstruction techniques has been shown to result in the lowest complication rate and best patient outcome?

Answer 44

Splitting of flexor-pronator mass, docking graft fixation.

Question 45

Hypophosphatasia is associated with which of the following laboratory findings

Answer 45

decreased serum alk phosphatase

Alkaline phosphatase is a marker of bone formation and is elevated when bone formation is increased. Hypophosphatasia is an autosomal recessive disorder caused by an inborn error in the production of alkaline phosphatase (tissue-nonspecific isoenzyme of alkaline phosphatase: TNSALP), leading to low alkaline phosphatase levels. Increased urinary phosphoethanolamine is also diagnostic.

Question 46

Arachidonic acid is directly metabolized by which of the following substances?

Answer 46

Arachidonic acid is the common substrate that is directly metabolized by cyclooxygenase into the prostanoids including prostaglandins, prostacyclin and thromboxane. Cyclooxygenase 1 enzyme, or COX-1, results in prostaglandins responsible for maintenance and protection of the GI tract. Cyclooxygenase-II enzyme, or COX-2, results in prostaglandins responsible for inflammation and pain. Leukotrienes are synthesized from arachidonic acid by 5-Lipoxygenase, not 1-Lipoxygenase. Mevalonate is involved in the HMG-CoA reductase pathway – the metabolic pathway that produces cholesterol (site of action of the statins). A diagram of arachidonic acid metabolism is provided in Illustration A.

Question 47

A 45-year-old male falls onto his left shoulder while biking and an injury radiograph is shown in Figure A (displaced mid clavicle fracture). He elects for nonoperative treatment. What is the most likely clinical outcome at one year after injury

Answer 47

decreased shoulder endurance and strength

Question 48

An island volar advancement flap was selected for wound closure. This method of thumb reconstruction is best indicated for which of the following sized defects?

Answer 48

2.5 cm

The Moberg flap with modifications to lengthen distal advancement as necessary is considered a standard option for medium-sized defects of the thumb pulp less than or equal to 2 cm.

Question 49

Which of the following skeletal dysplasias is caused by a sex linked mutation of the short stature homeobox (SHOX) gene?

Answer 49

Leri Weill dyschondrosteosis is a skeletal dysplasia characterized by short stature and bilateral Madelung deformities of the wrist. The SHOX gene is located on the X and Y chromosomes and a mutation on either of the sex chromosomes leads to the dysplasia (sex linked dominant).

Question 50

deformity nailing proximal tibia fracture

Answer 50

valgus, procurvatum

Question 51

Which of the following cytokines has been shown to promote scar tissue formation in lacerated skeletal muscle?`

Answer 51

tgf - beta

Question 52

Bonferroni correction

Answer 52

A Bonferroni correction is a post-hoc statistical correction made to P values when several dependent or independent statistical tests are being performed simultaneously on a single data set.

Question 53

Which of the following structures is the primary site of force transfer between the hindfoot and forefoot during the stance phase of gait?

Answer 53

plantar apponeurosis

Question 54

Which of the following structures are slowly adapting skin receptors that detect pressure, texture, and low frequency vibration and are best evaluated by static two-point discrimination?

Answer 54

merkels

paccinian is pressure

Question 55

What is the first class of antibody to appear in serum after exposure to a foreign antigen?

Answer 55

IgM

Question 56

superficial peroneal nerve is most at risk with which portal in ankle arthroscopy

Answer 56

anterolateral

Question 57

what is blood supply to physis/growth plate

Answer 57

Blood supply to the growth plate is supplied both via the perichondrial artery, which is the main source of nutrients, and the epiphyseal artery, which supplies the proliferative zone of the growth plate.

Question 58

What is the mechanism of action of vancomycin?

Answer 58

Vancomycin is an inhibitor of cell wall synthesis and is bactericidal for gram positive organisms

Question 59

Mineralization of the posterior-inferior glenoid has been implicated as a possible source of pain in which athletic population?

Answer 59

The Bennett’s lesion is mineralization of the posterior-inferior glenoid observed in overhead athletes. it is felt to be a traction spur of the posterior inferior glenohumeral capsule which is repetitively stressed during the deceleration and follow-through phases of the throwing cycle.

Question 60

how to treat a congenital clasped thumb

Answer 60

splinting for 3-6 months, then surgery if needed

Question 61

Dynamic exercise training can increase an athlete’s cardiac output through which of the following mechanisms?

Answer 61

increased stroke volume

The definition of cardiac output: CO = HR x Stroke Volume. Therefore, increasing the stroke volume, which is the amount of blood pumped by the heart with each contraction does increase the cariac output. Training usually results in a decreased resting heart rate. While training can increase your red blood cell mass and VO2 max (aerobic capacity), they do not affect output.

Question 62

A 21-year-old second-trimester pregnant female arrives in the trauma bay with a closed head injury as well as an open ankle injury. During evaluation, what positioning is recommended to limit positional hypotension?

Answer 62

left lateral decub (aorta is on left, vc on right)

Question 63

The ‘Risser sign’ is one of the most commonly used markers for skeletal maturation and growth potential in patients with adolescent idiopathic scoliosis. What ‘Risser sign’ has been shown to correlate with the greatest velocity of skeletal linear growth?

Answer 63

risser 0

Question 64

Altered BMP-4 signal transduction

Answer 64

Fibrodysplasia ossificans progressiva

Question 65

% vascular injury with knee dislocation

Answer 65

40%

Question 66

if calcium sulfate is used as the primary bone substitute void filler, an increase in which of the following outcomes may be expected as compared to autograft?

Answer 66

Wound drainage

Question 67

Atlantoaxial instability due to hypoplasia of the odontoid is most commonly seen in which type of mucopolysaccharidosis?

Answer 67

Odontoid hypoplasia is seen in association with Morquio’s syndrome.

Morquio’s syndrome is the most common mucopolysaccharidosis. It is characterized by the accumulation of keratan sulfate. Patients have proportionate dwarfism and normal intelligence. Spinal radiographs may show vertebral beaking or odontoid hypoplasia. The latter can lead to cervical instability. For patients with myelopathy associated with C1-C2 instability, decompression and cervical fusion are indicated.

Answer 1: Hurler’s syndrome may have C1-C2 instability, but not secondary to odontoid hypoplasia
Answer 3: Hunter’s syndrome is an X-linked recessive disorder and is characterized by mental retardation, proportionate dwarfism and clear corneas.
Answer 4: San Fillippo syndrome is characterized by the accumulation of heparan sulfate. Characteristics include mental retardation, proportionate dwarfism and clear corneas
Answer 5: Diastrophic dysplasia is causes by defects in the sulfate transporter gene. Cervical kyphosis may be severe and may lead to atlanto-axial instability. Cauliflower ears and hitchhiker thumbs are associated with this.

Question 68

Rotator cuff tears (full thickness and partial thickness) in asymptomatic individuals are seen on MRI or ultrasound in what percentage of patients over the age of 60?

Answer 68

The prevalence of asymptomatic rotator cuff tears diagnosed with MRI or ultrasound is quite high, with most studies noting tears in 30-54% of patients over the age of 60. The paper by Tempelhof et al utilized ultrasound and found tears in 30% of patients over 60. The study by Sher et al noted an overall prevalence of 54% on MRI in patients older than 60 (28% had full thickness and 26% with partial thickness). In both studies the frequency of tears increased substantially with increasing age.

Question 69

Ziehl-Neelsen stain

Answer 69

displays the mycobacterium as “red snappers” against a blue background.

for TB

Question 70

Which of the following is the most common intraoperative complication in a patient with sickle cell disease undergoing a total hip arthroplasty?

Answer 70

perforate femoral canal - bc its wide and there are areas that are dense next to weak areas

Question 71

Which of the following is indicative of type 1 collagen breakdown and can be utilized as a marker of bone turnover?

Answer 71

Urinary N-telopeptide is a marker of increased bone turnover and is a breakdown product of Type 1 collagen.

Increased serum alkaline phosphatase level and increased urinary markers of N-telopeptide, hydroxylproline, deoxypyridinoline indicate high bone turnover and can be seen in metabolic bone diseases such as Paget’s disease.

Question 72

Resection of the coracoacromial ligament during shoulder arthroscopy results in which of the following?

Answer 72

increased glen-humeral joint translation

Question 73

which bundle of elbow MCL is isometric

Answer 73

anterior

Question 74

What is the mechanism of action of capacitive coupling (CC) stimulation when used as an adjunctive therapy for bone healing?

Answer 74

Stimulates transmembrane calcium translocation via voltage-gated calcium channels

Question 75

When elevating the joint surface in the injury pattern seen in Figure A, what material has the highest compressive strength when filling the metaphyseal void?

Answer 75

calcium phosphate has greater compressive strength than cancellous bone

Question 76

Which of the following is true regarding closure of the rotator interval in patients undergoing arthroscopic shoulder stabilization?

Answer 76

It restricts external rotation predominately with the arm at 0 degrees of shoulder abduction

Question 77

The function of which of the following structures is to resist internal tibial rotation with the knee in full extension?

Answer 77

he primary function of the posterior oblique ligament is to resist internal tibial rotation with the knee in full extension.

Question 78

Which of the following terms is defined as a loss of function resulting from an anatomic or physiologic derangement

Answer 78

1) Apportionment: The process of determining the degree to which each of several exposures or injuries has contributed to a specific disability.
2) Impairment: Loss of function resulting from an anatomic or physiologic derangement. This is a medical designation that forms the basis for determining disability status.
3) Disability: Limitation of an individual’s capacity to meet certain personal, social, or occupational demands. This is not an objective medical designation, but a legal definition.