1. Intravenous antibiotic prophylaxis prior to skin incision is the most effective way to reduce the risk of postoperative wound infection after lumbar spine surgery. 2. For a patient undergoing knee replacement who has liver disease, the recommended venous thromboembolism prophylaxis includes use of mechanical prophylaxis like pneumatic calf compressors while in the hospital. 3. Bone morphogenetic proteins signal through serine-threonine kinase cell surface receptors.

1. 1. The risk forpostoperative woundinfectionafterlumbarspine surgeryisreduced
mostby the use of
A. iodine-impregnated preparation solution.
B.chlorhexidine-impregnated preparation solution.
C.greater than 10 minutes of surgical scrub.
D. intravenous antibiotic prophylaxis prior to skin incision.
E. laminar-flow air circulation.
2. A 68-year-old woman had advanced right knee arthritis and total
knee replacement was planned. She learned she had primary
biliary cirrhosis at age 41 and now has advancing liver failure.
Preoperative coagulation tests show a baseline International
Normalized Ratio (INR) of 1.36. Appropriate methods to prevent
thromboembolic disease as recommended by the 2011 AAOS
Clinical Practice Guideline, Preventing Venous Thromboembolic
Disease in Patients Undergoing Elective Hip and Knee Arthroplasty,
include
a. use of mechanical prophylaxis (eg, pneumatic calf compressors)
while in the hospital.
b. oral warfarin with a goal INR between 2.0 and 3.0.
c. low-dose warfarin for 3 weeks postsurgically beginning 48 hours
after surgery.
d. no prophylaxis because this patient already is partially
anticoagulated secondary to her liver disease.
3. Bone morphogenetic proteins transduce intracellular signal through
what class of cell surface receptor?
a. Mitogen-activated protein kinase
b. Tyrosine kinase
c. Serine-threonine kinase
d. Aurora kinase
e. Glycogen synthase kinase 3

2. 4. A 45-year-old man develops a nonunion after undergoing external
fixation of an open femoral shaft fracture. The procedure is revised
with an open reduction and internal fixation, all intraoperative
cultures are negative, and specimens from the fracture site are sent
for biopsy. Histological analysis most likely will reveal
a. positive gram stain and polymorphonuclear cells that are too
numerous to count.
b. bland-appearing cartilage callus.
c. Haversian remodeling.
d. lamellar bone.
5. A study is proposed in which 2 groups of patients are randomized
to treatment with bisphosphonates or placebo. This is an example
of what study type?
a. Crossover design trial
b. Parallel design trial
c. Cohort study
d. Case series
6. A hip compression screw is placed in a test jig and a bending load
is applied to the tip of the screw. After the load is released, the
screw returns completely to its original shape. What is this type of
deformation called?
a. Plastic
b. Elastic
c. Fatigue
d. Creep
e. Torsion
7. An 83-year-old woman reports pain in her left middle finger after a
minor injury. Laboratory studies show a WBC count of
7,000/mm>sup>3, an erythrocyte sedimentation rate of 3 mm/h, a
uric acid of 10.4 mg/dL, and a normal serum protein
electrophoresis. Radiographs are shown in Figures 49a and 49b.
A core biopsy specimen is shown is Figure 49c. In addition to
treatment of the finger fracture, treatment should include

3. a. colchicine and indomethacin
b. radiation therapy to the left hand.
c. systemic chemotherapy.
d. IV antibiotics.
e. through the wrist amputation.
8. An article in a leading orthopaedic journal describes a randomized
controlled study comparing 2 popular and comparable surgical methods
for fixation of hip fractures. Patients were randomized by a predetermined
computer-generated list. There was approximately 20% crossover
between treatment groups. Evaluation of study outcomes (clinical and
radiographs) was performed by one of the surgeons participating in the
study. Enrollment goals for appropriate power were achieved and final 1-
year follow-up was obtained for 65% of patients. According to Oxford
Group criteria, what is the appropriate level of evidence for this study?
a. Level I
b. Level II

4. c. Level III
d. Level IV
9. A patient with MRSA osteomyelitis experiences skin redness and
flushing with IV administration of vancomycin. The patient is
changed to IV linezolid therapy. Following the first dose of linezolid,
the patient reports headache, diaphoresis, and nausea. Physical
examination reveals unresponsive pupillary reaction, tachycardia,
hypertension, tremor, and clonus. In addition to discontinuing
linezolid, what is the next most appropriate step in management?
a. IV administration of benzodiazepines for control of serotonin
syndrome
b. IV administration of prednisone for abatement of allergic
reaction
c. Laboratory evaluation for examination of acute drug-induced
thrombocytopenia
d. Head CT for evaluation of possible acute cerebral hemorrhage
e. Spiral chest CT for evaluation of possible pulmonary embolus
10. A tendon repair is thought to be weakest during which phase of
tendon healing?
a. Inflammatory
b. Proliferation
c. Maturation
d. Remodeling
11.Sclerostin and dickkopf-1 (Dkk-1) are direct inhibitors of what
pathway related to bone and/or cartilage regulation?
a. Bone morphogenetic protein (BMP)/SMAD pathway
b. Receptor activator of nuclear factor kappa beta (RANK)/RANK
ligand (RANKL) pathway
c. Wnt/Beta-catenin (ß-catenin) pathway
d. Parathyroid hormone (PTH) pathway

5. 12.A 3-year-old child has bilateral genu varum and short stature.
Radiographs show physeal widening and generalized osteopenia.
The femora and tibiae show anterolateral bowing. Laboratory
studies show low normal serum calcium values, significantly
decreased serum phosphate levels, elevated alkaline phosphatase
levels, and normal parathyroid hormone (PTH),and vitamin-D
levels. These findings are most consistent with:
a. nutritional rickets.
b. renal osteodystrophy.
c. primary hyperparathyroidism.
d. hypophosphatasia.
e. vitamin D-resistant rickets.
13. In a hypothetical study, an investigator uses pedometers to
determine that the 20 women in his activity study averaged 2.1
million steps per year, whereas the 20 men averaged 1.8 million.
The p-value for this difference was 0.09. Which of the following is a
correct interpretation of the outcome of this study?
a. Since p > 0.05, the activity levels of women and men are
statistically equal.
b. If, in the general population, there is no difference between the
average activity levels of women and men, the difference
observed between the women and men in this study would
occur by chance selection in nine out of 100 times that the study
was performed.
c. The sample size was too small for this study, so the p-value has
no meaning.
d. Though a difference was measured between the two groups, the
findings are not clinically significant, since p > 0.05.
e. There is a 9% difference between the two groups because p =
0.09.
14.A 78-year-old woman has a history of chronic low back pain. She
denies any extremity problems. Her pain is worse in the morning,
and gets better, although it does not go away, as the day goes on.
An MRI scan of the lumbar spine is shown in Figure 88. She denies
any acute worsening of her symptoms, although in general, her
symptoms are slowly worsening. She takes nonsteroidal anti-

6. inflammatory drugs as needed for her pain, but otherwise takes no
other medications. What is the next most appropriate step in
management?
a. DEXA scan
b. Brace treatment with a Jewett hyperextension brace
c. Anterior lumbar corpectomy and arthrodesis with instrumentation
d. Posterior lumbar decompression and fusion
e. Vertebral cement augmentation
15.Receptor activator of nuclear factor kappa b (RANKL) and
macrophage colony stimulating factor (MCSF) signaling pathways
are necessary for the formation of multinucleated osteoclasts that
resorb bone. Which of the following cells are known to produce
RANKL?
a. Macrophages
b. Osteoclasts
c. Osteoblasts
d. Monocytes
e. Histiocytes