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Orthopedic Prometric Exam Preparation MCQs - Part 1

Orthopedic Prometric Exam Preparation MCQs - Part 16

25 Apr 2026 62 min read 1 Views
Orthopedic Prometric Exam Preparation MCQs - Part 16

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Question 1

A 4-year-old girl has unilateral idiopathic avascular necrosis involving the entire femoral head. Sixty percent of the height of the lateral column is resorbed. There is no lateral subluxation or physeal disturbance. The range of abduction is 30°. Recommended treatment consists of:





Explanation

The young age is the overwhelmingly positive factor in this patient. None of the findings mandate a more vigorous approach than observation. The Atlanta Scottish Rite orthosis has not been proven to have any effect on the disorder. Femoral osteotomy would only be possibly indicated, if there were subluxation greater than 25%. Iliac osteotomy would only be indicated in this age group, if there were subluxation and/or other poor prognostic factors. Petrie cast is indicated only if the patient has subluxation.

Question 2

A 13-year-old girl has hip pain and the inability to bear weight. On anteroposterior and lateral hip radiographs the femoral head is displaced inferiorly and posteriorly by 50% of its diameter. Recommended treatment includes:





Explanation

In situ fixation has results superior to any of the other methods. Besides being extremely cumbersome, spica cast treatment carries significant risk of redisplacement and chondrolysis. There is no indication for traction in this situation. The amount of displacement can be accepted as long as it is stabilized. Metaphyseal osteotomy carries a risk of avascular necrosis. It should only be undertaken in grade III slips.

Question 3

A newborn infant in the nursery must be seen because of his foot. The dorsum of the foot rests against the tibia. The heel moves up when the forefoot moves down. Power is present in all muscles. The foot has an arch and the leg lengths are equal. The diagnosis is:





Explanation

Calcaneovalgus foot has all of these findings and resolves spontaneously. Fibular hemimelia typically has less calcaneus attitude and more valgus and shortening. Vertical talus entails loss of an arch and loss of cohesive movement of the foot as a whole. There is no evidence of muscle weakness. There is no evidence of a neuropathic component.

Question 4

A newborn girl is noted to have decreased movement in the right upper extremity. She was large (10 lbs) at birth and was delivered vaginally with shoulder dystocia. She does not have elbow flexion, external shoulder rotation, or abduction. She has had weak finger flexion for 3 months. At 4-months-old, she regains the ability to flex her elbow. Recommended treatment includes:





Explanation

Conservative therapy is predicted to bring a good result because biceps are returning at four months of age. However, stretching of the shoulder is indicated to maintain a range of external rotation and abduction. Magnetic resonance imaging is only indicated if there is a need to consider microvascular repair. Tendon transfers are performed later (at several years of age), if shoulder abduction and external rotation are significantly limited. Microvascular repair is mainly considered in patients who do not have return of biceps function by five months. Open reduction is indicated later (if the shoulder joint is subluxated or severely contracted) after motor recovery has reached a plateau.

Question 5

A 7-year-old boy with diplegic cerebral palsy has had lengthening of his hamstrings and heelcords. He is examined 2 years later. He walks with the knees nearly straight throughout the gait cycle and circumducts each extremity during swing. This pattern is most likely due to:





Explanation

The straight legs and circumduction suggest spasticity of the rectus femoris as the most likely cause. Recurrent hamstring tightness (by itself) would cause the opposite combination of problems. Overlengthening of the heelcords usually causes increased dorsiflexion at the ankles and would help to increase the flexion moment rather than the extension. Contracture of the tensor fascia lata is extremely rare in cerebral palsy. Spasticity in the psoas muscle would not lead to a stiff knee gait.

Question 6

A 3-year-old girl is brought in for evaluation of leg alignment. She has bilateral foot progression angles of 35° internal. Her thigh-foot angles are 40° internal. Her hip rotation in the prone position is 50° external and 30° internal. The metaphysealdiaphyseal angle is 2° on each side. Recommended treatment includes:





Explanation

The tibial torsion described has an excellent chance of resolution over time. Observation is indicated. This child has tibial torsion. The Denis Browne bar has not been proven to affect the natural history of tibial torsion. The knee-ankle-foot orthoses are used for genu varum, which is not the primary problem in this case. A femoral osteotomy is rarely used to correct femoral anteversion in older children. A tibial osteotomy is rarely used to correct tibial torsion in older children.

Question 7

A newborn baby has a foot that is dorsiflexed and in valgus. The differential diagnosis includes all of the following conditions except:





Explanation

The foot in a patient with tibial hemimelia does not resemble the other four conditions described; the foot is in equinus and varus. Calcaneovalgus foot is dorsiflexed and everted through the axis of the ankle joint. A vertical talus has excessive forefoot dorsiflexion and valgus. A patient with an L5 myelomeningocele may have this appearance due to activity of the dorsiflexors and evertors, with absent power in the plantarflexors and invertors. Due to the posteromedial bow in the tibia, the foot may appear dorsiflexed and in valgus.

Question 8

A 6-year-old girl with osteogenesis imperfecta has severe bowing of both femurs. The family is interested in surgery to correct the condition. This method will give her the longest interval between procedures in the future:





Explanation

Telescoping or Bailey-Dubow rods are able to grow with the patient and maintain stabilization for a mean of 4 years between operations in growing children. Without the addition of internal fixation, bowing is likely to resume. Although a single rod is likely to provide current stability, bowing is likely to occur as the patient grows and the bone becomes longer than the rod. Parallel rods do not interlock and are likely to splay and lose fixation. There are no reports of large segment allograft replacement for diaphyses in osteogenesis imperfecta. In the absence of internal fixation, bowing is likely to resume as growth occurs.

Question 9

An infant is seen in the office for the first time. She has slender, stiff fingers with few creases, elbow range of motion 20° to 45°, and internally rotated arms. Her legs are flexed and externally rotated at the hip. Knee range of motion is 15° to 40° of flexion, and she has bilateral clubfeet that are stiff. The most likely diagnosis is:





Explanation

The patient has enough joint contractures to make arthrogryposis a likely diagnosis. Larsen syndrome is characterized by dislocation of multiple joints. Cerebral palsy is characterized by spasticity and flexors overpowering extensors. Ehlers-Danlos is characterized by hyperlaxity of the large joints. Down syndrome does not present with stiffness.

Question 10

Which of the following statements best characterizes the natural history of metatarsus adductus in a newborn:





Explanation

Virtually all patients with metatarsus adductus will improve with time in the absence of active treatment. Casts are not needed for the majority of cases because spontaneous improvement is by far the most common outcome. Reverse last shoes are not needed in the majority of patients with metatarsus adductus. Most patients will not need surgery. Equinus of the hindfoot is not part of the pathology in metatarsus adductus.

Question 11

A 2½-year-old boy has severe spastic diplegia and hips that are subluxating. His abduction is 20° on each side. The migration index is 35% on each side. Recommended treatment includes:





Explanation

If followed by postoperative bracing, lengthening of the adductors is usually successful in children younger than 4 to 6 years of age. Traction would not be appropriate because the muscles are spastic. The surgical plan does not include the most important component weakening the overactive adductors. Trochanteric transfer is not advisable in patients younger than 8 years old. Trochanteric transfer would not help decrease the overpull of the adductors which is the cause of the subluxation. Nighttime abduction splinting should be a component of the care after surgery. Bracing alone would not be an adequate treatment. Physical therapy in the absence of surgery does not seem to be enough to overcome the pull of the adductors.

Question 12

A 15-year-old boy has a Salter type-2 fracture of the distal tibia. His foot is in valgus and external rotation. Recommended treatment is:





Explanation

There is a good chance that a satisfactory closed reduction may be achieved by correcting the valgus and external rotation. The fracture should first be reduced. There is a good chance of a satisfactory reduction. The patient is old enough that a significant physeal growth disorder is not likely. Magnetic resonance imaging is not indicated unless there is a question of physeal disorder after healing or an entrapped fragment.

Question 13

Adolescent girls with multiple radiographs for idiopathic scoliosis are statistically at increased risk for which of the following problems later in life:





Explanation

In a historical cohort study, the risk was increased to 1.7 times the expected rate of breast cancer. The radiation dose is currently lower. The exposure to the breast may be lowered by taking posteroanterior rather than anteroposterior films, and eliminating lateral films in routine situations.

Question 14

The mean amount of growth height occurring in each vertbra per year during later childhood and early adolescence is:





Explanation

The mean growth is 0.7 mm per vertebra per year. This measurement is averaged across all of the thoracic and lumbar vertebrae.

Question 15

Which of the following features is true of congenital scoliosis but not infantile idiopathic scoliosis:





Explanation

In congenital scoliosis, the vertebrae are abnormally formed from birth. The vertebrae are normal at birth in infantile idiopathic scoliosis. Age of onset is before age 3 in both types of scoliosis. The thoracic curve may be convex to the left slide or the right side in either curve type. In infantile idiopathic scoliosis, it is most commonly convex to the left. The rib-vertebral angle difference (angle between the apical vertebral endplate and the rib on the convexity minus the rib on the concavity) greater than 20° predicts an increased risk of worsening in infantile idiopathic scoliosis but not in congenital scoliosis. Bracing has not been shown to affect infantile idiopathic scoliosis.

Question 16

A 12-year-old child with sickle cell anemia has had pain in the distal femur for 1 day, a temperature of 101.5° F, and a white blood count of 14,000/mm3 . Plain films are unremarkable. Recommended treatment includes:





Explanation

Because the odds are greatly in favor of a noninfectious process, it is appropriate to treat empirically with rehydration and analgesia. Magnetic resonance imaging would not distinguish between infection and vaso-occlusive crisis. Bone scan would not distinguish between infection and vaso-occlusive crisis. Needle biopsy is not necessary at this stage since the odds are high (greater than 95%) that the process is not infection. White blood cell scan is not able to distinguish between infection and vaso- occlusive crisis.

Question 17

A 6-year-old girl is wearing a seatbelt but no shoulder harness when the car she is occupying strikes another car. She suffers an abdominal contusion as well as a spine injury. The facets of L1 and L2 are spread apart as is the disk between them. The angle between the two vertebrae is 35°. The neurologic exam is within normal limits. Recommended treatment includes:





Explanation

Open reduction and 2-level fusion is the simplest way of handling this injury. Immobilization in a hyperextension cast is likely to exacerbate the abdominal injury. An orthosis is not likely to reduce the deformity. Traction would not be a good mechanism to reduce the deformity. In situ fusion would be insufficient without instrumentation.

Question 18

Secondary ossification of the elbow





Explanation

Secondary ossification is very imprtant in managing fractures. It begins at age 1-2 and is complete by 14 years girls and 16 years in boys.

Question 19

Definitive diagnosis of septic arthritis is made by:





Explanation

Definitive diagnoisis of septic arthritis is made by needle asperation.

Question 20

Osteomyelitis in the child





Explanation

Osteomyelitis in the child requires 3-6 weeks of antiobiotics which may be administered parenterally or internally.

Question 21

All of the following characterize lateral patellar compression syndrome except:





Explanation

By definition, patients with a lateral patellar compression syndrome do not have a subluxation or dislocation of the patella.

Question 22

Osteochondral defects occur bilaterally in the distal femur in approximately:





Explanation

Osteochondral defects occur bilaterally in the distal femur for approximately 20% to 30% of patients. The fact that 20% to 30% of patients with an osteochondral lesion in the distal femur have bilateral involvement suggests that there is a predisposition to the development of a lesion at this location, either genetic or secondary to repetitive microtrauma.

Question 23

The magnetic resonance imaging signs that suggest instability of an osteochondral dissecans lesion include all the following except:





Explanation

The presence of a high signal intensity line at the interface between the lesion and the underlying bone suggests instability of an osteochondritis dissecans lesion.

Question 24

The neonatal hand:




Explanation

The neonatal hand is proportionally different from the mature hand.

Question 25

Pediatric bone:





Explanation

Pediatric bone has less mineral and more vascular channels than adult bone. This gives it a lower bending strength and lower modules of elasticity than adult bone.

Question 26

In congenital lesions characterized by failure of formation of parts, the most functional, without treatment, is/are:





Explanation

C entral deficiencies allow a wide grasp, good release and pinch. These are also termed "cleft hand". The other conditions produce greater impairment.

Question 27

Which category of failure of formation anomalies is most often associated with systemic anomalies?





Explanation

Radial deficiencies are often seen in the later association. which may include cardiac,renal,anorectal and tracheoesphogeal abnormalities.

Question 28

Arthrogryposis multiplex congenita:





Explanation

Arthrogryposis multiplex congenita is an idiopathic disorder that may be due to a primary deficiency of anterior horn cells. Arthrogryposis multiplex congenita results in lack of muscle development; the joint stiffness is secondary to this. It is usually reasonably symmetrical.

Question 29

What percentage of the human genome represents the actual genes:





Explanation

The percentage of the genome that represents the sequence of our genes is approximately 5%. The rest of the genome codes are for initiator and termination sequences, maintenance functions, and unknown functions.

Question 30

In studying a newly recognized disorder using a large population of affected individuals, geneticists discover that although the disorder often affects siblings, it was rarely, if ever, detected in their ancestors. This disorder most closely follows which pattern of inheritance:





Explanation

Autosomal recessive conditions classically show â horizontalâ inheritance. Ancestors do not display the gene because they would likely have only one copy of the mutant allele. Only when two carriers reproduce is the phenotype manifest in approximately onefourth of their offspring. Autosomal dominant inheritance is characterized by vertical transmission. Many generations manifest the trait because it takes only a single copy of a mutant allele to display the phenotype. Sex-linked conditions are often traced back in a family. Normally the males are affected and the females are carriers. Multifactorial conditions are thought to result from the combination of different genes. Although the risk of recurrence in kindred is somewhat greater than the population as a whole, it is still quite low (only a few percent). It is rare for siblings to be affected. Anticipation refers to the phenomenon in which successive generations are likely to display more severe forms of a given disorder. Myotonic dystrophy is a classic example of this phenomenon.

Question 31

Diseas es caused by enzyme deficiency are commonly inherited by which of the following patterns:





Explanation

Two copies of a mutant allele are required to reduce enzyme function to levels that cause clinical impairment. Enzyme defects are rarely inherited by an autosomal dominant pattern because even half of the normal activity of most enzymes is adequate to maintain normal function. Enzyme defects are rarely inherited in an X-linked dominant pattern because one copy of a mutant allele is usually sufficient. Multifactorial inheritance refers to the interaction of multiple, or different genes, to produce a disorder. Enzyme deficiencies are typically the result of a defect in a single gene. Because enzymes are typically coded by a single gene, they follow mendelian patterns.

Question 32

Morquio syndrome is caused by a deficiency in:





Explanation

Morquio syndrome is a member of the family of mucopolysaccharidoses. Morquio syndrome is a deficiency in the enzyme galactose-6-sulfatase. A deficiency in galactose-6-sulfatase results in increased urinary excretion of keratosulfate. Alpha-L-iduronidase is deficient in Hurler syndrome. Beta-glucuronidase is deficient in some rare mucopolysaccharidoses. Fibroblast growth factor receptor protein is deficient in achondroplasia. Sulfate transport protein is deficient in diastrophic dysplasia.

Question 33

Polymerase chain reaction (PC R) is best characterized by which of the following descriptions:





Explanation

Polymerase chain reaction refers to denaturing DNA, isolating a segment of interest with known primers, and reannealing the strands multiple times to produce exponential copies of a segment.

Question 34

Pleiotropy is demonstrated by which of the following examples:





Explanation

The term pleiotropy refers to a disease taking different shapes in various patients. Variation in the severity of a given problem is better termed "variable expressivity." Target joints are not genetically determined. Hurler syndrome usually not being present in prior generations of an affected patient is an example of autosomal recessive inheritance. The term pleiotropy refers to a disease taking different shapes in different subjects, whereas the cause of patients with Ollier disease having more involvement on one side of the body is unknown.

Question 35

Which of the following is the most common concern regarding anesthesia for a patient with juvenile rheumatoid arthritis:





Explanation

Stiffness and mandibular hypoplasia are fairly common in juvenile rheumatoid arthritis (JRA) due to inflammation of the temporomandibular joint that affects the growth plates of the mandibles. Basilar invagination is rare in JRA. Rotatory subluxation of C1-C2 is rare in JRA. Subaxial subluxation is rare in JRA. Cervical stenosis is not a clinical problem in JRA.

Question 36

A 4-year-old boy is brought to a clinic because he has been fussy, febrile, and unable to bend over for the past 4 days. In the office, his temperature is 38.2° C and his neurologic examination is normal. His lumbar lordosis is flattened and he resists flexion or extension. He has normal range of hip motion. Plain films of the lumbar spine are normal. The next imaging study should be:





Explanation

Magnetic resonance imaging should be the next step to rule out pyogenic spondylitis. Ultrasound has not been proven effective in evaluation of anterior spinal pathology. Computed tomograms do not have a greater sensitivity than plain films in early diagnosis of infection. An indium labeled scan may yield diagnostic information but would not be the preferred test because of the time needed and inability to provide other diagnostic information. Hip arthrogram would not be the next step because the hip range of motion is normal. Even if hip pathology were suspected, the next step would be a plain film and an ultrasound.

Question 37

A 6-year-old child suffers a displaced fracture of the distal humerus in the supracondylar region. Neurologic and vascular exams are normal. The surgeon decides to reduce and pin the fracture. Which of the following risks increases if the procedure is delayed more than 8 hours?





Explanation

A retrospective comparison study has shown no increase of risks in delayed treatment of supracondylar fractures.

Question 38

Which of the following statements is true regarding the growth plates around the ankle:





Explanation

The distal tibia grows more than the distal fibula. The anterolateral portion of the tibial physis ceases growing last, thus explaining the phenomenon of the Tillaux fracture. The physis of the distal fibula is always located more distally than the distal tibia. The two physes are not conjoined.

Question 39

Which of the following is the most common final attribution of back pain in children and adolescents after all appropriate diagnostic studies are performed:





Explanation

The majority of children and adolescents do not have an identifiable cause of back pain after all appropriate tests are performed. Of the smaller percent of patients with an actual diagnosis, spondylolysis followed by herniated nucleus pulposus are most common.

Question 40

Which of the following is the most definitive means of making a diagnosis of active skeletal tuberculosis:





Explanation

The lower thoracic-upper lumbar spine is most commonly affected by tuberculosis. The most definitive diagnosis is by culture and histologic examination.

Question 41

Which of the following descriptions is more characteristic of tuberculosis than of pyogenic spondylitis:





Explanation

Vertebral destruction exceeds disc destruction in tuberculosis. Bony changes occur earlier in tuberculosis than in pyogenic spondylitis. Involvement of multiple contiguous levels is more common in tuberculosis than pyogenic spondylitis. Bony erosions seen on computerized tomography are large in tuberclosis and small in pyogenic spondylitis. Magnetic resonance imaging often shows significant soft tissue involvement in both disorders.

Question 42

A 5-year-old girl comes into the clinic with back pain. Her family has just moved to the United States from southeastern Asia. A lateral radiograph shows destruction of T11, T12, and L1. Magnetic resonance imaging shows a moderate posterior soft tissue mass. A neurological exam is normal. Biopsy confirms tuberculosis. For treatment of the girlâ s spinal problem, recommended treatment includes:





Explanation

Anterior debridement, strut graft, and posterior fusion with instrumentation provide the patient with the best chance of a positive result. This procedure minimizes graft dislodgement and posterior overgrowth. A two-drug therapy for at least 6 months leaves the patient at a significant risk of progressive kyphosis and neurologic deficit. A two-drug therapy for at least 6 months along with a body cast also leaves the patient with significant risk of progressive kyphosis and neurologic deficit. The lack of anterior support from a two-drug therapy and posterior spinal fusion to prevent deformity leaves the patient with significant risk of kyphosis. Even with an anterior spinal debridement and a rib strut graft, there is a risk of graft dislodgment over this large defect and of posterior growth into kyphosis.

Question 43

A dorsal approach has which of the following characteristics with regard to a posteromedial approach in the surgical treatment of congenital vertical talus:





Explanation

The dorsal approach has not shown evidence of avascular necrosis, whereas the posteromedial approach has shown such changes at follow-up in as many as 40% of cases. The dorsal approach requires a less extensive dissection than the posteromedial approach. The dorsal approach does not require or permit plication of the talonavicular capsule, whereas the posteromedial approach does. The dorsal approach does not appear to have a higher rate of redislocation of the talonavicular joint than the posteromedial approach. The dorsal approach requires a shorter tourniquet time than the posteromedial approach.

Question 44

Which of the following conditions is not associated with an increased risk of congenital vertical talus?





Explanation

Patients with cerebral palsy do not have an increased risk of congenital vertical talus, but they may develop an acquired neuromuscular vertical talus. Patients with myelomeningocele have approximately a 5% to 10% risk of vertical talus, far above that of the general population. Arthrogryposis is associated with an increased risk of vertical talus. Nail patella syndrome is associated with an increased risk of vertical talus. Sacral agenesis is associated with an increased risk of vertical talus.

Question 45

Scoliosis in Marfan syndrome, as compared to idiopathic scoliosis, is characterized by which of the following:





Explanation

Scoliosis curves are much more likely to begin in the juvenile period than idiopathic scoliosis. There is no significant difference in the likelihood of left thoracic curves in Marfan syndrome. Brace treatment is less likely to be successful in Marfan syndrome than in idiopathic scoliosis. Marfan patients with scoliosis are more likely to have back pain. Marfan curves are more likely to progress in adulthood.

Question 46

Which of the following statements is true of demineralized bone matrix:





Explanation

Demineralized bone matrix is weakly osteoinductive. The term osteogenic refers to direct transmittal of cells capable of making bone. Demineralized bone matrix is not osteogenic. Demineralized bone matrix varies in efficacy between different forms and different methods of sterilization. The term osteoconduction refers to provision of a favorable scaffold and environment for bone formation. Demineralized bone matrix is osteoconductive.

Question 47

A 16-year-old boy with type I Ehlers-Danlos syndrome has a spinal curvature that has progressed 18° in the past year. The curve is a double major type with a C obb angle of 60° in each curve. There is no associated kyphosis. The following treatment is recommend:





Explanation

Posterior fusion and instrumentation is the best-documented treatment. Although this form of treatment is followed by an increased incidence of wound healing problems, the problems can be treated. Observation is not recommended because the curve is highly likely to increase and cause a decrease in pulmonary function. Bracing has no role in large curves, and it is not known if bracing is successful at all in Ehlers-Danlos syndrome. Anterior fusion with instrumentation would be difficult with a double curve. Anterior fusion carries an increased risk due to vascular fragility. It is not necessary because there is no increased risk of crankshaft or pseudarthrosis. There is no particular reason for adding an anterior procedure in this situation in view of the vascular risk.

Question 48

Scoliosis in osteogenesis imperfecta is characterized by which of the following:





Explanation

Scoliosis in osteogenesis imperfecta (OI) is due primarily to ligamentous laxity. Scoliosis in OI is due primarily to ligamentous laxity, not bony fractures. There is no association between brainstem impression and scoliosis. Scoliosis in OI rarely responds to brace treatment. Scoliosis, when present in OI, is a major impairment of quality of life.

Question 49

Which of the following is not a specific feature in making the diagnosis of a dystrophic curve in neurofibromatosis 1:





Explanation

Vertebral rotation is not a specific characteristic of dystrophic curves. Rotation is more pronounced in dystrophic curves than in nondystrophic curves, but it is commonly present in both types of curves. Penciling of the ribs is one of the features specific for dystrophic curves in neurofibromatosis 1. Scalloping of the vertebrae anteriorly and posteriorly is characteristic of dystrophic curves in neurofibromatosis 1. Widening of the neural foramen is specific for dystrophic curves in neurofibromatosis 1. Widening of the neural foramen is due to tumorous masses passing through the foramen. Thinning of the transverse process is a characteristic of dystrophic curves in neurofibromatosis 1.

Question 50

The spine in familial dysautonomia is characterized by which of the following:





Explanation

There is an increased risk of loss of fixation in familial dysautonomia curves due to decreased bone density and curve rigidity. Scoliosis is common in patients with familial dysautonomia and affects up to one-half of patients with the disorder. The curves in familial dysautonomia are rigid, leading to limited correction. The bone density in familial dysautonomia is decreased. Spinal stenosis is not reported in patients with familial dysautonomia.

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Dr. Mohammed Hutaif
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Prof. Dr. Mohammed Hutaif
Consultant Orthopedic & Spine Surgeon
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