Full Question & Answer Text (for Search Engines)
Question 1:
A 5-year-old girl is brought to the emergency department because of fever and inability to walk. Her temperature is 100.5° F. She has pain with rotation of the hip. However, if the movement is done slowly, the hip can be rotated internally and externally 45°. Her white blood cell count is 13,000 (upper normal is 12,500 for her age). Her erythrocyte sedimentation rate is 30. Radiographs of the pelvis and hip are normal. You recommend:
Options:
- Bed rest with follow-up contact the next day
- Ultrasound of the hip
- Hip aspiration
- Magnetic resonance imaging
- Irrigation and drainage of the hip
Correct Answer: Bed rest with follow-up contact the next day
Explanation:
The scenario described above is most consistent with transient synovitis of the hip. Because range of motion is tolerated when performed slowly; it is compatible with a diagnosis of transient synovitis of the hip more than infection. Rest, with or without anti-inflammatory medicine, should produce a dramatic improvement by the next day.
Question 2:
Which of the following factors is least likely to predispose a patient to patellar instability:
Options:
- Genu varum
- Excessive femoral anteversion
- Patella alta
- External tibial torsion
- Hypoplastic lateral femoral trochlear ridge
Correct Answer: Genu varum
Explanation:
Genu varum does not predispose a patient to patellar instability. However, genu valgum, as well as all of the other factors listed above, may predispose a patient to this condition.
Question 3:
A 15-year-old girl twists her knee while skiing. She is diagnosed with a patellar dislocation. She has had no prior episodes. Radiographs show the dislocation but no other findings. After reducing the dislocation, you recommend:
Options:
- Knee immobilization for 2 to 3 weeks
- Long-leg cast for 6 weeks
- Repair of the medial patellofemoral ligament
- Tibial tubercle transfer
- Proximal realignment
Correct Answer: Knee immobilization for 2 to 3 weeks
Explanation:
Acute traumatic patellofemoral dislocations are best treated by brief immobilization followed by early rehabilitation. Surgery is reserved for patients with multiple recurrences that cause significant disability.
Question 4:
Which of the following is related to the etiology of Ewingâ s sarcoma:
Options:
- Chromosomal translocation (11/22)
- Viral infection
- Bacterial infection
- Trauma
- Single base mutation
Correct Answer: Chromosomal translocation (11/22)
Explanation:
Ewing s sarcoma belongs to the family of round cell sarcomas. A translocation t(11:22)(q24q12) has been discovered in Ewing ssarcoma. This translocation results in a novel protein, EWS-FL11, that causes rapid growth of cells arising from the neural crest.
Question 5:
A 5-year-old girl is brought to your office because of a mass in the back of her right knee. The family has noticed the mass for the past 8 months, and they also tell you that it varies in size with activity. The mass is painless and is located on the medial side of the popliteal fossa. It measures 2 cm to 4 cm and is discrete, firm, and nontender. Examinations of her knee and gait are unremarkable otherwise. You recommend:
Options:
- Observation with return if any changes
- Magnetic resonance imaging
- Aspiration
- Excisional biopsy
- Knee arthroscopy to look for intra-articular causes
Correct Answer: Observation with return if any changes
Explanation:
The patient history and physical examination are consistent with a benign popliteal cyst. This type of cyst is usually unassociated with any intra- articular pathology in children. The cyst resolves on its own with time. Further study or biopsy would be indicated only if the mass were progressively enlarging, tender, or located in an atypical area.
Question 6:
A 20-month-old toddler is brought in because of bowed legs. You note moderate-to-severe genu varum and thigh-foot angles of 35° inward. The child is otherwise healthy, and height and weight are near the 50th percentiles. Radiographs demonstrate tibial metaphyseal-diaphyseal angles of 8° on the right and 9° on the left. Femoral metaphyseal-diaphyseal angles are the same. You recommend:
Options:
- Observation, with return only if not improving
- Measurement of electrolytes, alkaline phosphatase, and vitamin D levels
- Serial casting until straight
- Bracing in knee-ankle-foot orthoses
- Osteotomies of the proximal tibias
Correct Answer: Observation, with return only if not improving
Explanation:
This child has physiologic genu varum. Only if the metaphyseal-diaphyseal angles were greater than 11° would additional followup be indicated, with possible bracing. Blood tests would be indicated if the bone quality showed evidence of Rickets or if the child was below the 10th percentile in height.
Question 7:
Which of the following is the most common complication after a posttraumatic distal radial growth arrest:
Options:
- Positive distal ulnar variance
- Negative distal ulnar variance
- Increased distal radial articular angle
- Decreased distal radial articular angle
- Distal radioulnar joint instability
Correct Answer: Positive distal ulnar variance
Explanation:
The most common complication after a posttraumatic distal radial growth arrest is positive ulnar variance (overgrowth). Other complications may include decreased distal radial articular angle, triradiate fibrocartilage tear, or distal radioulnar joint instability, but they are less common. Increased radial articular angle and negative ulnar variance rarely develop after these injuries.
Question 8:
Patients with which one of the following curve types associated with idiopathic scoliosis are at increased risk of shortness of breath:
Options:
- Thoracic curves larger than 80°
- Thoracolumbar curves larger than 80°
- Thoracolumbar curves larger than 100°
- Lumbar curves larger than 80°
- Lumbar curves larger than 100°
Correct Answer: Thoracic curves larger than 80°
Explanation:
Idiopathic scoliosis is associated with measurable decreases in pulmonary function in thoracic curves larger than 60° to 70°, but a clinically significant increase in risk of shortness of breath has been shown only in thoracic curves larger then 80°.
Question 9:
Which of the following patients with infantile idiopathic scoliosis can be observed without a magnetic resonance image (MRI):
Options:
- A patient with a curve less than 20°
- A patient with a normal neurologic examination
- A patient with a right thoracic curve
- A patient younger than 2 years old
- A patient without any pain
Correct Answer: A patient with a curve less than 20°
Explanation:
Patients with idiopathic infantile scoliosis have a 22% incidence of abnormalities that can be viewed on MRI. Syrinx and Chiari malformation are the most common abnormalities, with a similar rate as that found in patients with juvenile idiopathic scoliosis. The left thoracic curve pattern is most commonly seen in infantile patients, but a right thoracic curve is not protective. Age, freedom from pain, or a normal neurologic examination are also not protective. Magnetic resonance imaging is recommended for all infantile curves larger than 20°.
Question 10:
Which of the following features differentiates a grade 2 open fracture from a grade 1 open fracture:
Options:
- Laceration larger than 1 mm
- Laceration larger than 1 cm
- Laceration larger than 1 in
- Associated neurologic injury
- Associated vascular injury
Correct Answer: Laceration larger than 1 mm
Explanation:
A grade 2 open fracture is distinguished from a grade 1 open fracture by a laceration larger than 1 cm. Grade 3 open fractures are characterized by massive soft tissue damage, circulatory compromise, severe contamination, or marked instability. Grade 3A open fracture characteristics include extensive soft tissue lacerations but adequate skin to cover the bone. Grade 3B fractures show extensive soft tissue loss. Grade 3C open fractures demonstrate arterial injury and require repair.
Question 11:
Which of the following features differentiates a grade 3B open fracture from a grade 3C open fracture:
Options:
- Presence of neurologic injury
- Presence of vascular injury requiring repair
- Presence of vascular injury not requiring repair
- Segmental bone loss
- Massive contamination
Correct Answer: Presence of neurologic injury
Explanation:
Grade 3 injuries all have massive soft tissue damage. Grade 3C fractures have vascular injury requiring repair, whereas grade 3B fractures do not have vascular injury or do not require repair. An example of the latter is a severe open fracture of the distal tibia with laceration of the dorsalis pedis artery and a foot that is well perfused through its collaterals.
Question 12:
Which rating best describes a childs hip affected with Perthesâ disease that has healed with aspherical incongruity:
Options:
- C atterall 3
- C atterall 4
- Herring C
- Stulberg 4
- Stulberg 5
Correct Answer: Stulberg 5
Explanation:
The C atterall and Herring classifications are used during the evolution of Perthesâ disease to guide treatment; they are used during the fragmentation stage. It is impossible to know what the C atterall or Herring class was after healing has occurred. The Stulberg classification gives prognosis after healing. Stulberg 4 is aspherical but congruous. Stulberg 5 is aspherical and incongruous. Patients classified with Stulberg 5 hips typically have degenerative joint disease in early adulthood.
Question 13:
Which of the following agents is used to reverse the effects of midazolam:
Options:
- Naloxone
- Naltrexone
- Flumazenil
- Fentanyl
- Atropine
Correct Answer: Flumazenil
Explanation:
Flumazenil (reversed) is used to reverse the effects of benzodiazepines. Flumazenil has a shorter duration of action than benzodiazepines, so it may need to be readministered. Flumazenil can also precipitate seizures.
Question 14:
A 6-year-old boy is receiving pharmacologic agents to assist in the reduction of a forearm fracture. Which of the following conditions is not necessary for him to be in â conscious sedationâ :
Options:
- His consciousness is fully normal.
- He can open his eyes to command.
- His airway reflexes are maintained.
- He maintains a patent airway.
- His vital signs are stable.
Correct Answer: His consciousness is fully normal.
Explanation:
Under conscious sedation, a child must be able to open eyes to command, maintain a patent airway and reflexes, and have stable vital signs. However, consciousness is medically depressed by the drugs.
Question 15:
A mutation in type II collagen is responsible for all of the following conditions except:
Options:
- Stickler syndrome
- Spondyloepiphyseal dysplasia congenita
- Kniest syndrome
- Strudwick dysplasia
- Achondroplasia
Correct Answer: Achondroplasia
Explanation:
Type II collagen is largely found in hyaline cartilage. All of the dysplasias, with the exception of achondroplasia, have significant abnormalities of articular cartilage. Achondroplasia results from a defect in fibroblast growth factor receptor protein.
Question 16:
An adult man with hemophilia A has just announced the birth of his first son. His wife does not have the disease. What is the chance that the newborn has the disorder:
Options:
- 100%
- 50%
- 25%
- 10%
- Less than 1%
Correct Answer: Less than 1%
Explanation:
Hemophilia A is an X-linked disorder. Therefore, there is no father-son transmission. The chance that the newborn is affected equals that of the general population, which is less than 1%.
Question 17:
Which of the following conditions is least commonly seen in patients with congenital dislocation of the patella:
Options:
- Fibrosis of the vastus lateralis
- C ontracture of the iliotibial band
- Hypoplasia of the vastus medialis
- Enlarged patella
- Flexion contracture
Correct Answer: Enlarged patella
Explanation:
Congenital dislocation of the patella is present from birth and diagnosed in childhood. It is not reducible with the knee in extension. Essential elements include contracture of the iliotibial band, vastus lateralis, hypoplasia of the vastus medialis, lateral insertion of the patellar tendon, decreased size of the patella, flexion contracture and valgus alignment of the knee, and hypoplasia of the patellar sulcus. Operative treatment is usually successful, and the success rate is increased with early surgery.
Question 18:
The surgical reconstruction of a congenitally dislocated patella includes all of the following elements except:
Options:
- Advancement of the vastus medialis insertion
- Lengthening or release of the iliotibial band
- Lengthening or release of the biceps femoris muscle
- Lateral capsular release
- Lateral transfer of the patellar tendon insertion
Correct Answer: Lateral transfer of the patellar tendon insertion
Explanation:
The surgical reconstruction of a congenitally dislocated patella includes lengthening or release of the lateral capsule, lengthening or release of the iliotibial band, lengthening or release of the biceps femoris muscle, distal advancement or imbrication of the patellar tendon, and sometimes a rectus femoris lengthening. Semitendinosus transfer to the patella may also be added. The lateral insertion of the patellar tendon may be transferred medially.
Question 19:
Which of the following radiographic parameters is most appropriately used to assess the status of the hip in a growing child with cerebral palsy:
Options:
- The Stulberg rating
- The migration index of Reimer
- The alpha and beta angle of Graf
- Klein s line
- The Hilgenreiner-epiphyseal angle
Correct Answer: The migration index of Reimer
Explanation:
The migration index (of Reimer) is the percentage of the femoral head outside of the acetabulum. This radiographic parameter tracks the progress of the hip in patients with cerebral palsy because the femoral head may gradually migrate out. The other parameters refer to radiographic assessments of other hip disorders: The Stulberg rating is used in patients with healed Perthesâ disorder. The alpha and beta angles of Graf provide ultrasonic assessment of patients with developmental hip dysplasia. Klein s line is used in early detection of slipped capital femoral epiphysis. The Hilgenreiner-epiphyseal angle is used in developmental coxa vara.
Question 20:
What is the primary force applied to the spine during a C hance (seatbelt) fracture:
Options:
- Flexion
- C ompression
- Rotation
- Distraction
- Flexion and rotation
Correct Answer: Distraction
Explanation:
The primary force applied to the spine during a C hance fracture is distraction. The body is flexed forward around an axis in front of the body (often a seatbelt), but the spine is subject to distraction because it is posterior to this axis. This motion results in a characteristic distraction of bony or ligamentous elements with minimal crush.
