This practice set contains high-yield board review questions covering key concepts in 4. Pediatrics. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 1481
Topic: Pediatric Upper Extremity & Spine
A teenage female is referred to you for evaluation of curvature in her back that was discovered on routine school screening. She is diagnosed with adolescent idiopathic scoliosis. In which of the following scenarios is a bracing program the most appropriate treatment? Review Topic
Correct Answer & Explanation
. Left upper thoracic curve 16 degrees and right main thoracic curve 18 degress, Risser stage in figure B
Explanation
Bracing is most appropriate for skeletally immature patients with a curve > 20/25 degrees. Thus the patient with a left upper thoracic curve of 15 degrees and right main thoracic curve of 30 degrees in Risser stage 1 of growth meets criteria.The treatment of adolescent idiopathic scoliosis (AIS) depends on the magnitude and location of curve as well skeletal maturity of the patient. For curves less than 20 degrees, observation is appropriate until skeletal maturity, with closer intervals duringtimes of peak growth. Curves between 20-25 and 45 degrees in patients who are Risser stage 0,1 or 2 are best treated with bracing to stop progression. Curves with an apex at T7 or below are typically treated with a Boston brace. Curves over 50 degrees generally warrant a discussion about surgery to prevent progression past maturity.In a landmark study, Weinstein et al. evaluated both a randomized and preference based cohort of bracing versus observation. The trial was stopped early due to efficacy of bracing. The rate of treatment success was 72% after bracing and 48% after observation. Treatment success was strongly correlated to time of brace wear.Schlenzka et al. reviewed indications, treatment, and complications associated with brace treatment of AIS. They state that further evidence is necessary to evaluate the efficacy of bracing in AIS.Figure 1, 2, and 3 are radiographs depicting Risser stage 0, 1, and 4 respectively. Illustration B shows radiographs of all Risser stages. Illustration C is the Lenke classification system for idiopathic scoliosis.Incorrect Answers:
Question 1482
Topic: 4. Pediatrics
Figure 47 shows the radiograph of a 2-day-old girl who has been referred for swelling and limited use of the right upper extremity. The second of twins, the infant was breech and delivered with forceps at age 38 weeks, weighing 5.37 lb. Difficulty in moving the arm was noted shortly after birth. Examination shows no active motion of the shoulder, elbow, or wrist. Active finger flexion and extension are present. The elbow is mildly swollen, and passive motion shows lack of full extension of 20°, lack of full flexion of 15°, and no restriction of pronation or supination. What is the most likely diagnosis?
Correct Answer & Explanation
. Obstetrical brachial plexus palsy
Explanation
DISCUSSION: Fractures involving the entire distal humeral physis may be a complication of a difficult delivery. Basing the diagnosis on radiographs can be difficult at this age because the secondary ossification center of the lateral condyle has not developed. The key to the diagnosis is the constant relationship of the radius and ulna, with medial and posterior displacement of the forearm relative to the humerus. An ultrasound can be obtained to confirm the diagnosis in newborns. Because the fracture is through cartilage, examination may reveal only mild swelling, and crepitation may be muffled or not apparent. The lack of apparent active motion of the shoulder, elbow, and wrist is secondary to pseudoparalysis. Child abuse is a common mechanism of this injury in a child who is age 1 month to age 3 years.REFERENCES: Beaty JH, Wilkins KE: Fractures involving the entire distal humeral physis, in Rockwood CA, Wilkins KE, Beaty JH (eds): Fractures in Children, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, vol 3, pp 790-801.Dias JJ, Lamont AC, Jones JM: Ultrasonic diagnosis of neonatal separation of the distal humeral epiphysis. J Bone Joint Surg Br 1988;70:825-828.Gruel CR, Sullivan JA: Transcondylar fractures of the distal humerus, in Letts RM (ed): Management of Pediatric Fractures. New York, NY, Churchill Livingstone, 1994, pp 199-209.
Question 1483
Topic: Pediatric Hip
A 53-year-old man with a history of severe left hip pain has a significant limp that is the result of a 5-cm limb-length discrepancy. An AP radiograph is shown in Figure 48. The underlying etiology is most likely related to a history of
Correct Answer & Explanation
. Legg-Calve-Perthes disease.
Explanation
DISCUSSION: Radiographic abnormalities such as coxa magna, coxa breva secondary to growth arrest, and coxa plana and acetabular deformities are associated with healed Legg-Calve-Perthes disease. Femoral heads that were flat yet congruent with the acetabulum are at risk for disabling arthritis in the sixth decade of life in 50% of these untreated patients. As the normal ball-and-socket joint deforms to a flattened cylinder, the hip loses abduction and rotation capability, while retaining flexion and extension potential. If the femoral head is flat and is not concentric with the acetabulum, early severe arthritis occurs. Hinge abduction and anterior impingement are known sequelae of a flat, incongruent femoral head.REFERENCE: Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, IL, American Academy of Orthopedic Surgeons, 1999, pp 3-23.
Question 1484
Topic: 4. Pediatrics
Figures 51a and 51b show the radiographs of a 12-year-old boy obtained after an attempted closed reduction of an elbow injury in the emergency department. His motor examination is intact but he reports decreased sensation along the palmar aspect of his ring and little finger. What is the best treatment plan? Review Topic
Correct Answer & Explanation
. Open reduction and internal fixation
Explanation
The radiographs reveal an incarcerated medial epicondyle fracture apparently associated with an elbow dislocation. The incarcerated position of the fragment warrants open reduction and internal fixation. Due to the close proximity of the ulnar nerve, percutaneous pinning of a medial epicondyle fracture is not recommended. Ulnar nerve symptoms secondary to this fracture usually do not require a formal transposition.(SBQ13PE.97) A 3-year-old boy presents to your office for evaluation. On physical examination, the patient has large calves and uses his hands to assist in rising from the floor. Laboratory results from the pediatrician reports notably high creatinine kinase of 43000 IU/L. What is the most likely inheritance pattern?Review TopicAutosomal recessiveAutosomal dominantX-linked recessiveX-linked dominantMitochondrial inheritanceDuchenne's muscular dystrophy (DMD) has an X-linked recessive inheritance pattern.Duchenne's muscular dystrophy is characterized by a lack of dystrophin on muscle biopsy. Gower's sign is a typical physical exam finding (child uses hands to assist in rising from sitting), along with pseudohypertrophy of the calves. Notable laboratory values include elevated creatinine kinase (CK), typically above 25,000 IU/L.Sussman et al. provide a comprehensive review of DMD, highlighting characteristic findings, including pseudohypertrophy of the calves (due to replacement of skeletal muscle with adipose tissue), Gower's sign, as well as CK levels typically above 25,000 IU/L. CK levels can aid in distinguishing between Becker's dystrophy which has levels less than 25,000 IU/L.Figure A exhibits a muscle biopsy (calf) at low power of DMD; note the replacement of muscle with adipose tissue.Incorrect answers:(SBQ13PE.47) Figure A shows an ultrasound of a 2 week old infant being evaluated for developmental dysplasia of the hip. Which of the labels depict the alpha angle, and what anatomic landmarks define this angle?Review TopicAngle A, ilium and cartilaginous acetabulumAngle A, ilium and bony acetabulumAngle B, ilium and cartilaginous acetabulumAngle B, ilium and bony acetabulumAngle B, bony acetabulum and acetabular labrumThe alpha angle is subtended by (1) a line drawn down the ilium to a point where it intersects with the bony and cartilaginous confluence of the acetabulum and (2) a line drawn along the roof of the bony acetabulum.The coronal flexion view (as depicted in figure A) of the infant hip is perhaps more familiar if rotated 90 degrees to view as one would view an anterior posterior radiograph of the pelvis. Acetabular development is evaluated primarily by the alpha angle, indicating the morphology of the developing acetabulum, and the percentage of the femoral head that is covered by the bony acetabulum. These are each readily apparent on ultrasound. Normal hips should have an alpha angle of at least 60 degrees by 6-8 weeks of age.Harcke et al. provide a current concepts review on the state of ultrasound in the diagnosis and management of developmental dysplasia of the hip (as of 1991). They report, since that time, ultrasound has become the mainstay for diagnostic confirmation and management of DDH.LeBa et al. performed a study to look at whether ultrasound screening would increase in effectiveness if targeted toward infants with established risk factors for developmental dysplasia of the hip and normal findings on physical examination. They found dynamic ultrasound evaluation showed developmental dysplasia in 7.8% of patients who had normal physical exams and led to a change in treatment in 8%. They conclude selective ultrasound screening in infants with risk factors and normalfindings on physical examination is effective and leads to more effective treatment.Figure A shows an ultrasound exam of a 2 week old infant. The alpha angle is labeled 'B'. The beta angle is lableled 'A'. Illustration A is a diagram from Tachdjian's illustrating diagrammatically the elements of these angles.Incorrect answers.
Question 1485
Topic: 4. Pediatrics
The newborn foot deformity seen in Figures 64a and 64b should initially treated with
Correct Answer & Explanation
. observation with possible stretching.
Explanation
DISCUSSION: Mild to moderate metatarsus adductus is best treated with observation and possible passive stretching exercises because most of these feet will self correct. Numerous types of shoes, braces, and splints have been devised but the efficacy of these have not been determined. Serial casting is reserved for severe metatarsus adductus in the infant, although a medial surgical release may be indicated if the deformity is symptomatic and persists beyond age 4 years.REFERENCES: Abel MF (ed): Orthopaedic Knowledge Update: Pediatrics 3. Rosemont, IL, American AcademAyL-oMfadOenrathCooppayedic Surgeons, 2006, pp 240-241.Farsetti P, Weinstein SL, Ponseti IV: The Long-term functional and radiographic outcomes of untreatedand non-operatively treated metatarsus adductus. J Bone Joint Surg Am 1994;76:257-265. Question 65A 4-year-old girl has been limping for the past 2 months. There is no history of trauma, previous injury, fever, or other systemic complaints. Examination reveals a moderate right knee effusio n with a 10-degree knee flexion contracture. What is the next most appropriate step in evaluation?ArthroscopyAntinuclear antibodyMRIBone scanHLA-B27DISCUSSION: The patient presents with juvenile idiopathic arthritis manifestations. The American College of Rheumatology defines this as one or more joints involved with swelling of 6 weeks or longer. A positive antinuclear antibody test would be diagnostic. Consideration should be made to have the patient see an ophthalmologist for evaluation of possible uveitis. Although the patient could have Lyme disease, that choice is not an option. The presence of an elevated antinuclear antibody by itself should not necessarily be used for diagnosing arthritis; however, the test does have clinical utility as a screening test. The frequency of a positive antinuclear antibody test is greatest in younger girls with oligoarticular disease and carries an increased risk for anterior uveitis. Arthroscopy might be indicated if this patient was presenting with a discoid meniscus, but there is no history of clicking, which is often one of the classic signs of discoid meniscus. MRI would not be used to diagnose juvenile idiopathic arthritis, butMRI would be useful to help diagnose discoid meniscus. A bone scan would show increased uptake in the patient’s knee but again, this would not help diagnose her condition. HLA-B27 has no role in diagnosing juvenile idiopathic arthritis, especially in females.REFERENCES: Iesaka K, Kubiak EN, Bong LR, et al: Orthopaedic surgical management of hip and knee involvement in patients with juvenile rheumatoid arthritis. Am J Orthop 2006;35:67-73.Wright DA: Juvenile idiopathic arthritis, in Morrissey RT, Weinstein SL (eds): Loveland Winter’s Pediatric Orthopaedics, ed 6. Philadelphia PA, Lippincott Williams and Wilkins, 2006, pp 405-438. Question 66An 18-month-old girl is brought in by her parents because of concerns about intoeing, bowlegs, and tripping and faling. Prenatal and birth history are otherwise unremarkable. The child’s growth anddevelopment appear to be normal and she has a normal neurologic exam, a straight spine with no defects, and the hips are stable. Examination reveals hip internal rotation of 40 degrees and hip external rotation of 60 degrees. The thigh-foot angle is internal 30 degrees. Feet are straight and supple. Gait is characterized by intoeing with occasional tripping and falling. Based on these findings, what is the most appropriate action?No treatment because internal tibial torsion slowly resolves on its ownImmediate treatment with a Denis-Browne barDistal tibial osteotomiesProximal femoral derotational osteotomiesTreatment with twister cables PREFERRED RESPONSE: 1DISCUSSION: The child has classic internal tibial torsion that is very commonly seen in younger children who are just beginning to walk. The normal outcome is for slow resolution of this problem and it seldom requires any treatment. Treatment with a Denis-Browne bar or with twister cables has not been proven to be effective. Surgical treatment at this point is premature and clearly not indicated.REFERENCES: Lincoln TL, Suen PW: Common rotational variations in children. J Am Acad Orthop Surg 2003;11:312-320.Staheli LT, Corbett M, Wyss C, et al: Lower-extremity rotational problems in children: Normal values to guide management. J Bone Joint Surg Am 1985;67:39-47.
Question 1486
Topic: 4. Pediatrics
An 8-year-old boy with moderate factor VIII hemophilia played kickball earlier in the day and now reports progressively severe groin pain and is unable to walk. Examination reveals marked paresthesias over the medial aspect of the distal tibia. What is the most likely diagnosis?
Correct Answer & Explanation
. Hemorrhage into the iliacus muscle
Explanation
DISCUSSION: The iliacus muscle is a frequent site of hemorrhage in patients with severe or moderate hemophilia. In patients with moderate hemophilia, hemorrhage into the iliacus muscle often follows play or sporting events that include forceful contraction of the hip flexor muscles. An expanding iliacus hematoma compresses the adjacent femoral nerve, with one study reporting 60% complete femoral nerve palsy in hemophiliacs with an iliacus or iliopsoas hemorrhage. Femoral nerve compression typically includes paresthesias in the distribution of the terminal saphenous nerve branch. Hip joint hemarthrosis may occur, but this condition is not as frequent in hemophiliacs as muscle hemorrhage into the iliacus muscle. More importantly, a hip joint hemarthrosis is not associated with significant compression of the femoral nerve. Avulsion fractures of the anterior superior iliac spine typically occur during adolescence and are not associated with saphenous nerve paresthesias. Slipped capital femoral epiphysis does not have an increased association with hemophilia and usually occurs during the adolescent years.REFERENCES: Greene WB: Diseases related to the hematopoietic system, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 5. Philadelphia, PA, Lippincott Williams and Wilkins, 2001, pp 379-426.Gilbert MS, Radomisli TE: Therapeutic options in the management of hemophilic synovitis. Clin Orthop 1997;343:88-92.
Question 1487
Topic: 4. Pediatrics
An obese 4-year-old boy has infantile Blount’s disease. Radiographs reveal a metaphyseal-diaphyseal angle of 18 degrees and a depression of the medial proximal tibial physis. Management should consist of
Correct Answer & Explanation
. proximal tibial osteotomy that produces 10 degrees of valgus.
Explanation
DISCUSSION: The deformity is too severe for observation, and at age 4 years, the child is too old for orthotic treatment. To prevent recurrence, surgery should be performed before irreversible changes occur in the medial physis. A proximal tibial osteotomy should overcorrect the mechanical axis to 10 degrees of valgus. Bar resection has not been shown to be as effective in this severe deformity, especially without a concomitant osteotomy.REFERENCES: Raney EM, Topoleski TA, Yaghoubian R, Guidera KJ, Marshall JG: Orthotic treatment of infantile tibia vara. J Pediatr Orthop 1998;18:670-674.Loder RT, Johnston CE: Infantile tibia vara. J Pediatr Orthop 1987;7:639-646.
Question 1488
Topic: Pediatric Upper Extremity & Spine
In girls with idiopathic scoliosis, peak height velocity (PHV) typically occurs at what point?
Correct Answer & Explanation
. Before Risser 1 and menarche
Explanation
DISCUSSION: PHV generally occurs while girls are still Risser 0; menarche typically occurs before Risser 1, which has a wide variation in its timing. The curve magnitude at the PHV is the best prognostic indicator available. Most untreated patients with curves greater than 30 degrees at PHV require surgery, while patients with smaller curves at that stage typically do notrequire surgery.REFERENCES: Little DG, Song KM, Katz D, Herring JA: Relationship of peak height velocity to other maturity indicators in idiopathic scoliosis in girls. J Bone Joint Surg Am2000;82:685-693.Anderson M, Hwang SC, Green WT: Growth of the normal trunk in boys and girls during the second decade of life; related to age, maturity, and ossification of the iliac epiphyses. J Bone Joint Surg Am 1965;47:1554-1564.
Question 1489
Topic: 4. Pediatrics
What is the most appropriate way to communicate instructions to a family when there is a language barrier?
Correct Answer & Explanation
. Use a professional medical interpreter
Explanation
DISCUSSIONIdeally, professional medical interpreters should be used in situations involving language difficulties. Printed instructions are helpful, but, if there is a language barrier, these instructions cannot substitute for conversing and answering questions. Asking the child to translate (no matter how fluent he or she may be) is suboptimal. Nonmedical staff may not be fluent enough to adequately translate medical terms.RESPONSES FOR QUESTIONS 14 THROUGH 16Aspiration, cultures, surgical irrigation and debridement, and intravenous (IV) nafcillinAspiration, cultures, surgical irrigation and debridement, and IV vancomycinAspiration, cultures, Lyme serology, and oral amoxicillinBiopsy, culture, curettage, bone graft, and possible internal fixationPhysical therapy, ibuprofen, and an antinuclear antibody testSelect the most appropriate treatment above to address each clinical scenario below.
Question 1490
Topic: Pediatric Hip
An otherwise healthy adolescent girl was treated for left slipped capital femoral epiphysis. The contralateral hip had not slipped, but was stabilized prophylactically with a single cannulated screw. The implants were removed after 1 year. The pelvic radiographs (Figures 215a and 215b) and the MRI scans of the hip that had not originally slipped (Figures 215c through 215e) were obtained 10 months after screw removal (22 months after the original fixation). Which findings are shown in these studies?
Correct Answer & Explanation
. Both hips are normal and no further assessments will be needed.
Explanation
Question 1491
Topic: 4. Pediatrics
Regarding the role of the orthopaedic surgeon in addressing domestic and family violence, all of the following statements are true EXCEPT:
Correct Answer & Explanation
. Report all cases of child abuse, as this is required by all states
Explanation
DISCUSSION: Reporting requirements for adult spousal or intimate partner abuse is not standardized among states and it is the responsibility of the orthopaedic surgeon to understand the laws of his or herstate. The AAOS Advisory statement gives information to assist in meeting the ethical and legal obligations on Domestic and Family Violence and Abuse.Domestic and family violence affects over 10% of the US population (approximately 32 million Americans). Child abuse and neglect contributed to 1,400 fatalities in 2002 and there was 565,747 reports of suspected elder abuse.Reporting of suspected child abuse is required in all states. The orthopaedic surgeon should hospitalize elderly victims who are in immediate danger and help develop a plan to insure their safety.
Question 1492
Topic: 4. Pediatrics
Avascular necrosis
Correct Answer & Explanation
. Slipped epiphysis
Explanation
SlideA 9-year-old girl sustains an injury (Slide) as a result of a fall. What is her risk of avascular necrosis:
Question 1493
Topic: 4. Pediatrics
A non-communicative 16-year-old girl with spastic quadriplegic cerebral palsy and a 75-degree thoracolumbar scoliosis undergoes a successful posterior spinal fusion with instrumentation. What is the most predictable outcome of the surgical procedure?
Correct Answer & Explanation
. Improved cognitive function
Explanation
DISCUSSION: Surgical treatment of spinal deformity in a totally involved child with cerebral palsy has been shown on outcomes instruments to significantly improve the caregiver’s perception of the child’s comfort. The other parameters mentioned are difficult to measure and unpredictable.REFERENCES: Tsirikos Al, Lipton G, Chang WN, et al: Surgical correction of scoliosis in pediatric patients with cerebral palsy using the unit rod instrumentation. Spine 2008;33:1133-1140.Cassidy C, Craig CL, Perry A, et al: A reassessment of spinal stabilization in severe cerebral palsy. J Pediatr Orthop 1994;14:731-739.
Question 1494
Topic: 4. Pediatrics
A 2-week-old infant has been referred for evaluation of nonmovement of the left hip. History reveals that the patient was delivered 6 weeks premature by cesarean section. Examination reveals no fever, and there is mild swelling of the thigh. Passive movement of the hip appears to elicit tenderness and very limited hip motion. A radiograph of the pelvis shows mild subluxation of the left hip. The next step in evaluation should consist of
Correct Answer & Explanation
. aspiration of the left hip.
Explanation
DISCUSSION: The diagnosis of bone and joint sepsis in a newborn is difficult because of the relative lack of obvious signs and symptoms. Fever is usually absent. A study of 34 newborns with osteomyelitis identified prematurity and delivery by cesarean section as predisposing factors. In that study, the most common clinical findings were pseudoparalysis, local swelling, and pain on passive movement. Because early diagnosis is so important, any infant who exhibits these findings should be suspected as having bone or joint sepsis. Once the area of involvement is identified, aspiration is mandatory. In newborns who have an infection about the hip, radiographs may reveal subluxation. In this patient, septic arthritis must be ruled out by aspiration of the hip. Developmental dysplasia of the hip is not painful and is not accompanied by localized swelling. If no purulent material is obtained at the time of hip aspiration, an arthrogram should be obtained to rule out epiphysiolysis of the proximal femur. Because the area of involvement has been identified by clinical examination, a gallium scan or MRI scan of the spine is not indicated.REFERENCES: Knudsen CJ, Hoffman EB: Neonatal osteomyelitis. J Bone Joint Surg Br 1990;72:846-851.Morrissy RT: Bone and joint sepsis, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 4. Philadelphia, Pa, Lippincott-Raven, 1996, pp 579-624.
Question 1495
Topic: 4. Pediatrics
Which of the following patients with cerebral palsy is considered the ideal candidate for a selective dorsal rhizotomy?
Correct Answer & Explanation
. An ambulatory 6-year-old patient with spastic diplegia
Explanation
DISCUSSION: The enthusiasm with which dorsal rhizotomy was received led to the broadening of selection criteria with poorer results. The ideal candidate is an ambulatory 4- to 8-year-old child with spastic diplegia who does not use assistive devices or have joint contractures. The child must be old enough to actively participate in the rigorous postoperative physical therapy program. The use of the procedure in an ambulatory 16-year-old patient is less desirable because joint contractures will most likely have developed to a varying degree. The hemiplegic child is best treated by orthopaedic interventions.REFERENCES: Oppenheim WL: Selective posterior rhizotomy for spastic cerebral palsy: A review. Clin Orthop 1990;253:20-29.Renshaw TS, Green NE, Griffin PP, Root L: Cerebral palsy: Orthopaedic management. J Bone Joint Surg Am 1995;77:1590-1606.Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1996, pp 19-27.
Question 1496
Topic: 4. Pediatrics
What is the mechanism of action of an intramuscular injection of botulinum type A toxin in reducing spasticitiy?
Correct Answer & Explanation
. Blocks the release of presynaptic acetylcholine release at the neuromuscular junction and end plate
Explanation
DISCUSSION: The use of intramuscular botulinum type A toxin has been shown to be a useful adjuvant in the management of dynamic deformity in patients with cerebral palsy. Botulinum type A toxin is a neurotoxin produced by Clostridium botulinum that works by interfering with presynaptic acetylcholine release at cholinergic nerve terminals. At the cellular level, the mechanism involves endocytosis of the intact botulinum toxin molecule by cells in the end plate, followed by disulfide cleavage and translocation of the light chain into the cytosol where it disrupts the normal binding of the synaptosomal vesicles to the axon terminal membrane. Neither the nerve terminal nor the neuromuscular junction is damaged. The muscle paralysis is reversible and dose-dependent. Baclofen is a neuropharmacologic agent that functions as a GABA agonist. Dorsal rhizotomy is a neurosurgical procedure that reduces spasticity by dividing afferent (excitatory) fibers in the posterior rootlet of the spinal nerves.REFERENCES: Koman LA, Mooney JF III, Smith B, Goodman A, Mulvaney T: Management of cerebral palsy with botulinum-A toxin: Preliminary investigation. J Pediatr Orthop 1993;13:489-495.Brin MF: Botulinum toxin: Chemistry, pharmacology, toxicity, and immunology. Muscle Nerve Suppl 1997;6:S146-168.
Question 1497
Topic: 4. Pediatrics
2010 Pediatric Orthopaedic Examination Answer Book • 9 A 9-year-old girl has had bilateral knee and leg pain for the past 2 years. The family has noted increasing deformity in both lower extremities. She is less than the fifth percentile for height. Examination reveals bilateral femoral bowing, mild medial-lateral laxity of the knees, and the deformities shown in the radiograph seen in Figure 3. What is the most likely diagnosis?
Correct Answer & Explanation
. Renal osteodystrophy
Explanation
DISCUSSION: The widening, bowing, and cupping of the physes indicate some form of metabolic bone disease; therefore, the most likely diagnosis is renal osteodystrophy. The age of onset makes X-linked hypophosphatemic rickets less likely. The ground glass lesions and widening of the medullary canal characteristic of fibrous dysplasia are not present. There are no fractures creating the deformities indicating osteogenesis imperfecta.There is an asymmetry of the deformities that makes diastrophic dysplasia less likely.REFERENCES: Goldberg MJ, Yassir W, Sadeghi-Nejad A: Clinical analysis of short stature. J Pediatr Orthop 2002;22:690-696.Parmar VS, Stanitski DF, Stanitski CL: Interpretation of radiographs in a pediatric limb deformity practice: Doradiologists contribute? J Pediatr Orthop 1999;19:732-734. Question 4Patients with slipped capital femoral epiphysis are more likely to experience a delay in definitive diagnosis if they initially present to a physician reporting which of the following problems?L LimpHip painKnee painProximal thigh painButtock painDISCUSSION: A delay in diagnosis of slipped capital femoral epiphysis (SCFE) can lead to significant worsening of the deformity or even progression from a stable to an unstable SCFE. Those patients that report knee pain as their primary complaint are most likely to experience significant delay. Other variables associated with this delay include Medicaid insurance and stable SCFE.REFERENCES: Kocher MS, Bishop JA, Weed B, et al: Delay in diagnosis of slipped capital femoral epiphysis.AL-Madena Copy10 • American Academy of Orthopaedic SurgeonsPediatrics 2004;113:e322-e325.Rahme D, Comley A, Foster B, et al: Consequences of diagnostic delays in slipped capital femoral epiphysis. J Pediatr Orthop B 2006;15:93-97.
Question 1498
Topic: Pediatric Hip
A 12-year-old child falls from his bicycle and injures his right knee. Evaluation in the emergency department reveals knee effusion and pain with extremes of range of motion. Radiographs are shown in Figures 13a and 13b. Attempts at closed reduction are made and he is placed in a long leg cast with the knee flexed at 10 to 20 degrees. At follow-up, repeat radiographs continue to show anterior displacement of the fracture. What structure is most likely entrapped under the fragment?
Correct Answer & Explanation
. Anterior fat pad
Explanation
DISCUSSION: Avulsion fractures of the tibial spine are a relatively rare injury in children. Historically, the most common cause of this fracture was falls from bicycles, but with the increased participation in competitive sports, the etiology is changing. Most fractures occur in children ages 8 to 14 years, and they typically present with a painful hemarthrosis and refusal to bear weight. The Meyers and McKeever classification is based on degree of displacement, where type I is minimally displaced, type II is anteriorly displaced with an intact posterior hinge, and type III is completely displaced. The Ilia and Illb modifications have been added to account for fragment comminution and rotation, respectively. Long leg casting is advocated for type I fractures, though there is debate whether the knee should be maintained in full extension or in 10 to 20 degrees of flexion. Management of type II and III fractures is much more controversial. Type II fractures can be treated closed if adequate reduction can be achieved, but if not, surgical management is indicated. Surgery is also indicated for type III fractures, and results of open versus arthroscopic procedures are similar long term. Kocher and associates examined 80 consecutive skeletally immature patients with type II or III tibial eminence fractures that were treated surgically. They found that the anterior hom of the medial meniscus was entrapped beneath the displaced fracture fragment in 36 of 80 cases, whereas the lateral meniscus was only entrapped in 1 of 80 cases. This is not to be confused with the datafrom Lowe and associates in JBJS 2002 where they found the lateral meniscus to be involved in blocking reduction. This was not thought due to entrapment of the lateral meniscus. Rather, with the anterior cruciateligament and lateral meniscus still being attached to the avulsed fracture fragment, they felt the two structures were pulling in opposite directions and therefore blocking reduction of the fragment.REFERENCES: Falstie-Jensen S, Sondergard-Petersen PE: Incarceration of the meniscus in fractures of the intercondylar eminence of the tibia in children. Injury 1984;15:236-238.Kocher MS, Micheli LJ, Gerbino P, et al: Tibial eminence fractures in children: Prevalence of meniscal entrapment. Am J Sports Med 2003;31:404-407.Accousti WK, Willis RB: Tibial eminence fractures. Orthop Clin North Am 2003;34:365-375.Lowe J, Chaimsky G, Freedman A, et al: The anatomy of tibial eminence fractures: arthroscopic observations following failed closed reduction. J Bone Joint Surg Am 2002;84:1933-1938.Figure 14a Figure 14b Figure 14c Question 14A 14-year-old boy underwent in situ screw fixation for a left slipped capital femoral epiphysis 8 months ago. Henoted 3 months of intermittent right hip pain but is presently asymptomatic. The last episode of pain was 2 days prior to this office visit. He reports that he has pain approximately once a week over the past 3 months. Examination of the right hip is normal, and includes pain-free internal rotation. Radiographs and an MRI scan are shown in Figures 14a through 14c. Treatment should consist of which of the following?In situ screw fixation of the right hipPhysical therapyLimitation of activities and return to the clinic if pain persistsBiopsy of the femoral neck lesionIrrigation and debridement of the right hip PREFERRED RESPONSE: 1DISCUSSION: The patient history is concerning for a pre-slip slipped capital femoral epiphysis (SCFE) of the right hip. In one study, nearly 40% of patients with SCFE had bilateral involvement, and of that 40%, half presented initially with a unilateral SCFE but had a subsequent SCFE on the contralateral limb. Radiographs are normal, but the MRI scan shows increased signal about the proximal femoral physis. Treatment should include prophylactic screw fixation of the right hip.REFERENCES: Aronsson DD, Loder RT, Breur GJ, et al: Slipped capital femoral epiphysis: Current concepts. J Am Acad Orthop Surg 2006;14:666-679.Loder RT, Aronson DD, Greenfield ML: The epidemiology of bilateral slipped capital femoral epiphysis: A study of children in Michigan. J Bone Joint Surg Am 1993;75:1141-1147.Loder RT: Controversies in slipped capital femoral epiphysis. Orthop Clin North Am 2006;37:211-221, vii.Figure 15a Figure 15b
Question 1499
Topic: 4. Pediatrics
Spondyloepiphyseal dysplasia congenita and tarda, precocious osteoarthropathy, and Stickler syndrome are caused by a mutation in the gene coding for
Correct Answer & Explanation
. type-I collagen
Explanation
Precocious osteoarthropathy is due to a mutation at 12q13.11-q13.2. It causes type-II collagen disorders. Spondyloepiphyseal dysplasia congenita and tarda are autosomal dominant and recessive disorders, respectively. They also affect the gene site for coding for type-II collagen (12q13.11-q13.2). Stickler syndrome, or hereditary arthro-ophthalmopathy, is secondary to changes in type-II collagen. Stickler syndrome without eye involvement is due to mutations in type-XI collagen. Achondroplasia involves a mutation in FGFR3. Alpert syndrome is due to defects with FGFR2. Ehler-Danlos is an example of type-I collagen mutations. Type I Multiple epiphyseal dysplasia and Pseudoachondroplasia involves a defect in cartilage oligomeric protein.
Question 1500
Topic: Pediatric Upper Extremity & Spine
A 34-year-old man underwent a transtibial amputation as the result of a work-related injury. The amputation was performed at the inferior level of the tibial tubercle. The residual limb has a soft-tissue envelope composed of gastrocnemius muscle that is used as soft-tissue cushioning for the distal tibia. Despite undergoing several prosthetic fittings, he continues to report pain and instability. Examination reveals that the prosthesis appears to fit well with no apparent pressure points or areas of skin breakdown. He is not willing to have any further surgery. Which of the following modifications will most likely provide relief?
Correct Answer & Explanation
. Add double metal uprights and a leather corset.
Explanation
DISCUSSION: While transtibial amputees can be fitted with a prosthesis with a residual limb as short as 5 cm, or with retention of the insertion of the patellar tendon, this patient has an unstable gait because of the limited ability of the prosthetic socket to maintain a snug and stable fit. While cumbersome and bulky, double metal uprights and a corset is the only predictable method of gaining stability. The other methods attempt to add an element of stability; however, they are unlikely to be successful.REFERENCES: Bowker JH, Goldberg B, Poonekar PD: Transtibial amputation: Surgical procedures and postsurgical management, in Bowker JH, Michael JW (eds): Atlas of Limb Prosthetics. St Louis, MO, Mosby Year Book, 1992, pp 429-452.Kapp S, Cummings D: Transtibial amputation: Prosthetic management, in Bowker JH, Michael JW (eds): Atlas of Limb Prosthetics. St Louis, MO, Mosby Year Book, 1992, pp 453-478.
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