Full Question & Answer Text (for Search Engines)
Question 1:
At which age do patients most commonly present with dysplasia epiphysialis hemimelia (DEH):
Options:
- Birth
- Between early childhood and early teen years
- Early adulthood
- Middle age
- Older than 60 years
Correct Answer: Birth
Explanation:
Most cases of DEH occur in patients between early childhood and early teen years. Dysplasia epiphysialis hemimelia does not present at birth.C orrect Answer: Between early childhood and early teen years
Question 2:
This radiograph (Slide) shows an 11-month-old girl with a Tonnis 3 developmental dislocation of the hip. Recommended treatment includes:
Options:
- Pavlik harness
- C losed reduction and spica cast application
- Open reduction and spica cast application
- Open reduction with femoral shortening derotation osteotomy
- Open reduction with Salter osteotomy
Correct Answer: C losed reduction and spica cast application
Explanation:
Closed reduction and spica cast application is the best treatment for this patient with a Tonnis 3 developmental dislocation of the hip. Open reduction and spica cast application introduces additional risks of infection and vascular compromise and should not be performed unless closed reduction and spica cast application fails. This patient is too old to be controlled by a Pavlik harness.
Question 3:
The mechanical axis of the lower extremity is defined as the angle formed by lines drawn from the center of the hip to the center of the knee to the center of the ankle. The resulting value should be:
Options:
Correct Answer: 10°
Explanation:
The mechanical axis should be 0°. Alignment following correctional osteotomies and arthroplasties must re-establish the mechanical axis.
Question 4:
A 2-year-old boy presents with intoeing. An examination shows that his feet form an angle of 20° inward with the direction he is walking. Which of the following parameters describes his condition:
Options:
- Thigh-foot angle
- Tibial torsion angle
- Angle of femoral anteversion
- Foot progression angle
- Transmalleolar axis
Correct Answer: Foot progression angle
Explanation:
The 20° inward angle formed with the direction the patient is walking is a foot progression angle. This angle encompasses all factors influencing position and progression of the lower extremity during gait.
Question 5:
Which of the following measurements reflects the mean lateral distal femoral joint angle with respect to the mechanical axis:
Options:
Correct Answer: 87°
Explanation:
The lateral distal femoral angle with respect to the mechanical axis is 87°.
Question 6:
A 2-year-old patient presents with bowed legs. The metaphyseal diaphyseal angle is 17°, and the mechanical axis shows 15° of varus bilaterally. The varus appears to be in the proximal tibia. No evidence of metabolic disease or dysplasia is present. Recommended treatment inlcudes:
Options:
- Observation
- Knee-ankle-foot orthosis
- High tibial osteotomy
- Medial staple hemiepiphysiodesis
- Percutaneous hemiepiphysiodesis with drill
Correct Answer: Knee-ankle-foot orthosis
Explanation:
This patient has infantile Blount disease. Brace treatment is appropriate to try, although it is not always successful. The best treatment is for the patient to wear a knee-ankle-foot brace full-time. High tibial osteotomy, medial staple hemiepiphysiodesis, and percutaneous hemiepiphysiodesis are inappropriate treatments for this patient at 2 years old. If the varus does not improve by the time the patient is 3.5 years old to 4 years old, then high tibial osteotomy should be performed.
Question 7:
A newborn infant presents with a knee complication. The patientâ s knee hyperextends to 30° and flexes to 30°. The neurovascular examination is normal, and the patientâ s hips are stable. No other skeletal complications are found. Radiographs show a line along the axis of the tibia intersecting the ossific nucleus of the distal femur, signaling significant hyperextension. Recommended treatment inlcudes:
Options:
- Observation
- Serial casting
- Pavlik harness
- Prone skin traction to gradually flex the leg
- Open reduction of the knee with V-Y plasty
Correct Answer: Observation
Explanation:
This patient has a hyperextensible, but not dislocated, knee. In the radiograph, the line along the axis of the tibia would intersect the femur anterior to the ossific nucleus if the patientâ s knee were dislocated. Hyperextensible knee is an in utero complication and resolves without treatment.
Question 8:
A 12-year-old girl has genu valgum and requests correction. Radiographs reveal 12° valgus of the mechanical axis, with 2° arising in the distal femur and 3° arising in the proximal tibia. No evidence of other disorders are present. Recommended treatment includes:
Options:
- Observation
- Knee-ankle-foot orthosis worn at night
- Medial distal femur staple hemiepiphysiodesis
- Lateral opening wedge osteotomy of the distal femur
- Medial closing wedge osteotomy of the proximal tibia
Correct Answer: Medial distal femur staple hemiepiphysiodesis
Explanation:
This patient has a significant amount of valgus. Valgus at the knee is evident when signaled by even a low number of degrees. The patient is at an age when medial distal femur staple hemiepiphysiodesis would be the best treatment for genu valgum. Medial distal femur staple hemiepiphysiodesis is a safe and effective procedure and is performed using small incisions, which allow for immediate ambulation.
Question 9:
Which of the following conditions is not part of the differential diagnosis of a valgus knee in a 4-year-old child:
Options:
- Physiologic valgus
- Prior proximal metaphyseal fracture
- Multiple exostoses
- C hondroectodermal dysplasia
- Infantile Blount disease
Correct Answer: Infantile Blount disease
Explanation:
Physiologic valgus, prior proximal metaphyseal fracture, multiple exostoses, and chondroectodermal dysplasia produce valgus. Infantile Blount disease produces varus.
Question 10:
Which of the following methods of treatment has the lowest success rate in treating patients with congenital pseudarthrosis of the tibia:
Options:
- Electromagnetic stimulation
- Vascularized fibula graft
- Ilizarovs method
- Intramedullary (IM) rod fixation and bone graft
- Ilizarovs method over an intramuscular rod
Correct Answer: Electromagnetic stimulation
Explanation:
Electromagnetic stimulation has the lowest success rate in treating patients with congenital pseudarthrosis of the tibia. Vascularized fibula graft, Ilizarovâ s method, IM rod fixation and bone graft, and Ilizarovâ s method over an intramuscular rod have similar success rates.
Question 11:
Which of the following methods of measuring limb length inequality includes the greatest number of factors leading to pelvic height difference:
Options:
- Scanogram
- Orthoroentgenogram
- Tape method
- Block method
- Teleroentgenogram
Correct Answer: Block method
Explanation:
The block method consists of adding height to the short limb in blocks until the pelvis is level. The block method measures differences in foot height and pelvic size as well as inequalities of the long bones. Because the teleroentgenogram shows the whole limb in one exposure, the exposure is susceptible to be parallax and distorted at the ends. The orthoroentgenogram and scanogram measure limb length inequality similarly, but the scanogram captures only the joints and eliminates the diaphyses.
Question 12:
A patient with myelomeningocele is a community ambulator. She has a minimal Trendelenburgâ s sign but has a calcaneus gait. Her motor level is:
Options:
Correct Answer: L5
Explanation:
A calcaneus gait describes heel strike with no pushoff. This patient has active anterior tibialis with no gastrocsoleus. The Trendelenburgs test shows that her gluteals are minimal at less than L4. The patientâ s motor level is L5.
Question 13:
An 8-year-old child with spina bifida has a focal kyphosis measuring 100° with an apex at the first lumbar vertebra and a short trunk. The patients family is concerned about the childâ s risk of skin breakdown posteriorly. Recommended treatment includes:
Options:
- Milwaukee brace
- C orrection in a hyperextension cast followed by a Milwaukee brace
- Posterior fusion in situ to produce correction with growth
- Anterior strut grafting
- Posterior vertebral excision and instrumentation
Correct Answer: Posterior vertebral excision and instrumentation
Explanation:
This patient has myelokyphosis, which occurs in some patients with a thoracic level of spina bifida. The myelokyphosis is caused by a lack of posterior spinal osteoligamentous elements and denervated musculature and has a sharp, single apex with a compensatory lordosis above and below the apex. Myelokyphosis is steadily progressive with growth. Bracing and casting are ineffective treatments for patients with myelokyphosis due to the focality of the complication and insufficient skin coverage over the apex. Posterior fusion in situ is mechanically ineffective in controlling the large focal curve occurring in myelokyphosis. Anterior strut grafting in a growing child functions as an anterior bar that exacerbates the patientâ s myelokyphosis. A kyphectomy is the best treatment for a patient with myelokyphosis. A kyphectomy entails a posterior resection of the apical vertebra and posterior instrumentation. Posterior instrumentation corrects the cantilever. A kyphectomy does not entail fusion beyond the resected area because such a fusion impedes growth.
Question 14:
This is a radiograph of a patient with myelomeningocele. At which of the following levels is the lesion located:
Options:
Correct Answer: L4
Explanation:
This patient has active quadriceps (which are innervated through L2-L4) and adductors (which are innervated through L1-L3). Because the patientâ s knees are slightly hyperextended there is no hamstring function. The patientâ s right foot has some dorsiflexion. The lesion is rated as L4. However, the patientâ s right side may be rated as L3.
Question 15:
A 1-year-old patient with L4 myelomeningocele presents with a foot complication. Radiographs are shown in neutral plantarflexion (Slide 1) and in maximal plantarflexion (Slide 2). Recommended treatment includes:
Options:
- Ponsetiâ s cast treatment
- Orthotic treatment
- Complete subtalar release
- Open reduction of congenital talonavicular dislocation
- Excision of midtarsal bone
Correct Answer: Open reduction of congenital talonavicular dislocation
Explanation:
This patient has a congenital vertical talus, also known as a congenital dorsolateral dislocation of the talonavicular joint. Because the navicular is not yet ossified, the dorsal position of the first metatarsal line illustrates evidence of the patients congenital vertical talus when compared to the position of the talus. The congenital vertical talus is fixed because it does not become reduced upon maximum plantarflexion. The best treatment for congenital vertical talus is open reduction of the congenital talonavicular dislocation, with tendon lengthening.
Question 16:
An 8-year-old girl with myelomeningocele has sustained warmth and swelling of her leg for 2 weeks. She does not recall any trauma. She has had a temperature of 101° on several occasions. Her radiograph (Slide) is shown below. The most likely diagnosis is:
Options:
- Osteomyelitis of the tibia
- Fracture of the distal tibia
- Deep venous thrombosis
- Ewingâ s tumor
- Osteogenic sarcoma
Correct Answer: Fracture of the distal tibia
Explanation:
This patient has a Salter 1 physeal fracture of the distal tibia, which was probably caused by stress that remained unrecognized due to the patientâ s lack of pain. Patients with spina bifida experience extensive periosteal reaction because they do not get early immobilization.
Question 17:
This radiograph (Slide) shows a 5-year-old boy with an L4 myelomeningocele. He can ambulate with a walker. Recommended treatment includes:
Options:
- Observation
- Abduction bracing
- Bilateral adductor tenotomy
- Bilateral adductor tenotomy and femoral osteotomy
- Bilateral adductor tenotomy, femoral and iliac osteotomy
Correct Answer: Observation
Explanation:
This patient has symmetrical high, longstanding dislocations. Because his level is L4, he has no abductor function. The patient has multiple contraindications to surgery, including current symmetry, lack of abduction power, young age, and an inability to walk without a walker. His ability to walk would likely be hindered by surgery.
Question 18:
The first radiograph (Slide 1) shows the pelvis of a patient with L3 myelomeningocele at 9 years old. The second radiograph (Slide 2) shows the pelvis of the same patient taken 2 years later. Which of the following factors most likely contributed to the change in the patientâ s pelvis:
Options:
- Increased standing activity in therapy
- Excessive sitting
- Adductor tenotomy
- C hiariâ s malformation
- Tethered cord
Correct Answer: Tethered cord
Explanation:
Note that the radiograph in Slide 1 shows normal hip joints, and the radiograph in Slide 2, which was taken 2 years later, shows symmetric dislocation. This patient has a tethered cord. The tethered cord caused increased spasticity, resulting in the spontaneous dislocation of the patient's hips during the 2 years between the time the two radiographs were taken.
Question 19:
In which of the following molecules is McC une-Albrightâ s syndrome due to a mutation:
Options:
- Fibroblast growth factor receptor protein
- GNAS1
- Bone morphogenetic protein
- Fibrillin
- C ollagen type 1
Correct Answer: GNAS1
Explanation:
McC une-Albrights syndrome (also known as polyostotic fibrous dysplasia) is due to a mutation in GNAS1. GNAS1 is the alpha subunit of GS, which is a protein that links receptors to adenyl cyclase activity.
Question 20:
Which of the following symptoms is not characteristic of McC une- Albrights syndrome:
Options:
- Cafa-au-lait spots with irregular borders
- Cafa-au-lait spots with smooth borders
- Precocious puberty
- Diabetes mellitus
- Hyperthyroidism
Correct Answer: Cafa-au-lait spots with irregular borders
Explanation:
The cafa-au-lait spots associated with McC une-Albrightâ s syndrome are described as â coast of Maineâ spots because they have irregular borders. The café-au-lait spots associated with neurofibromatosis are described as â coast of C aliforniaâ spots because they have smooth borders.
