116 B Day (12/4 A & B 12/5) Daily Mastery Plan

Front 1

In patients with cerebral palsy, voluntary control of motion best predicts improvement in function after which of the following? 1-Botox injection; 2-Selective dorsal rhizotomy; 3-Wrist/hand tendon transfer surgery; 4-Femoral derotational osteotomies; 5-Tibial derotational osteotomies

Back 1

Tendon transfer surgery is used to maximize function in patients with cerebral palsy.

Van Heest et al. (1999) evaluated 134 patients where 718 procedures were performed in the upper extremities. Treatment was tailored to each child's needs and included soft tissue releases of deforming spastic muscles, tendon transfers to augment antagonistic activity, and joint stabilization. Using a 9-level functional use score, the authors showed an average improvement of 2.6 functional levels for all patients. Patients with good voluntary control had the greatest improvement in functional use scores.Ans3

Front 2

Which of the following decreases acetylcholine levels in the synaptic cleft by blocking the presynaptic release of acetylcholine? 1-Lidocaine
2-Botulinum toxin A; 3-Acetylcholinesterase; 4-Baclofen; 5-Pyridostigmine

Back 2

Decreased acetylcholine levels in the synaptic cleft weaken the strength of muscle contraction and are used in the treatment of spastic muscle disorders like cerebral palsy. While botulinum toxin A, acetylcholinesterase, and baclofen all decrease muscular contraction, only botulinum toxin A does so by blocking the presynaptic release of acetylcholine. Baclofen acts as a Gamma-aminobutyric acid (GABA) agonist. Gamma-aminobutyric acid blocks both the presynaptic and postsynaptic release of acetylcholine. Acetylcholinesterase is an enzyme that degrades acetylcholine. Pyridostigmine blocks the function of acetylcholinesterase, thus increasing acetylcholine levels. Finally lidocaine blocks the voltage gated sodium channels, unrelated to acetylcholine metabolism. Abbruzzese and Berardelli review the mechanism of action, treatment options, and side effects of botulinum toxin type A.Ans2

Front 3

Achondroplasia results from abnormal chondrocyte function in the physis. What receptor is defective and what region of the physis is affected? 1. FGFR-3, zone of proliferation; 2. FGFR-2, zone of proliferation; 3. FGFR-3, zone of hypertrophy; 4. FGFR-2, zone of hypertrophy; 5. COMP, zone of hypertrophy

Back 3

Achondropasia is caused by a mutation in the FGFR-3 receptor in the zone of proliferation. This is a gain of function mutation which enhances tyrosine kinase activity resulting in increased inhibition of chondrocyte proliferation and differentiation, the features of achondroplasia which include rhizomelic dwarfism (proximal shortening) and genu varum. It is helpful to remember that spinal manifestations develop at different ages: foramen magnum stenosis during infancy, thoracolumbar kyphosis when sitting begins, and spinal stenosis as early as the second decade, Answer 2 & 4: Apert's syndrome is caused by a genetic defect in the FGFR-2
Answer 5: COMP defects =Pseudoachondroplasia, multiple epiphyseal dysplasia type I (MEN), and McKusick's metaphyseal chondrodysplasia.Ans1

Front 4

An 18-year-old male complains of a painful prominence over his medial midfoot for the past 2 years; NSAIDs and orthotics have failed to provide relief. Physical exam demonstrates a firm, nonmobile, tender bump on the medial midfoot with no skin changes. A radiograph is provided in figure A. Which of the following is the best treatment option? 1-Total contact cast
2-Steroid injection; 3-MRI of the foot and chest CT scan; 4-Open bx; 5-Surgical excision

Back 4

The radiograph demonstrates an accessory navicular. Conservative measures are the first line treatment for the symptomatic accessory navicular. Surgical excision is a reliable intervention for cases refractory to conservative management.Ans5

Front 5

Anterolateral tibial bowing is associated with which of the following lower extremity conditions in children? 1-Calcaneovalgus foot deformity
2-Congenital pseudoarthrosis of the tibia; 3-Fibular hemimelia; 4-Congenital talipes equinovarus
5-Congenital vertical talus

Back 5

Anterolateral tibial bowing and congenital pseudoarthrosis of the tibia are related conditions and represent a continuum of the same disease process. It is most commonly seen in children with neurofibromatosis. The radiograph in Illustration A is an example of anterolateral tibial bowing. The radiograph in in Illustration B is an example of congenital pseudoarthrosis of the tibia.
vascularized fibular transplantation was the most effective and safest surgical technique to tx=congenital pseudarthrosis of the tibia. Other options include: IM fixation (Williams rod), prophylactic fibular allograft, and ex-fix, Bowing of the tibia that is present at birth typically occurs either anteriorly (in association with fibular hemimelia), anterolaterally (in association with congenital pseudoarthrosis), or posteromedially (in association with calcaneovalgus foot deformity). Congential talipes equinovarus (clubfoot) and congenital vertical talus are not associated with any specific tibial bowing deformities.Ans2

Front 6

A heterozygous loss of function mutation in which of the following genes would result in cleidocranial dysplasia? 1. BMP-2; 2. cAMP; 3. c-fos; 4. SOX-9;
5. RUNX2

Back 6

RUN Forest Run= Cleidocranial dysplasia is a skeletal disorder with autosomal dominant inheritance. The clinical hallmarks of CCD are short stature, delayed closure of cranial fontanels and sutures, Wormian bones, frontal bossing, supernumerary and late erupting teeth, rudimentary or absent clavicles, wide pubic symphysis, and other skeletal anomalies. RUNX2, also known as Cbfa-1, is a transcription factor associated with osteoblast differentiation.

The reference by Khoshal et al reviews the orthopedic issues with campomelic dysplasia, which has improved life expectancy due to improvements in pulmonary treatment(s). There are several types of campomelic dysplasia; however, it is characterized by the presence of anteriorly bowed tibias with cutaneous dimpling, anterolaterally bowed femurs, thoracic kyphoscoliosis, hypoplastic scapulas, and absence or delayed ossification of thoracic pedicles, 1: BMP-2 loss of function does not lead to cleidocranial dysplasia
2: overproduction of cAMP causes overexpression of c-fos, which regulates proliferation and differentiation of osteoblasts and osteoclasts, mutations in cAMP can lead to fibrous dysplasia
3: c-fos regulates proliferation and differentiation of osteoblasts and osteoclasts
4: campomelic dysplasia is caused by mutations in the SOX-9 gene.Ans5

Front 7

An 8-year-old boy presents with extreme shoulder motion and frontal bossing. A chest radiograph and AP pelvis radiograph are shown. What is the most likely diagnosis? 1. Cleidocranial dysplasia; 2. Renal osteodystrophy; 3. Spondyloepiphyseal dysplasia tarda; 4. Hypothyroidism; 5. Bilateral slipped capital femoral epiphyses

Back 7

The clinical presentation and radiographs are consistent with cleidocranial dysplasia, which is an autosomal dominant form of proportionate dwarfism. The radiographs in Figure A show clavicle dysmorphism. The pelvic radiographs in Figure B shows failure of the pubic symphysis to ossify and distinctive lateral notching of the capital femoral epiphysis. Cleidocranial dysplasia primarily involves bones formed by intramembranous ossification such as facial bones, cranium, and clavicles. The result is failure of formation of midline structures, such as the clavicle and pubic symphysis. Additional clinical features include growth retardation, craniofacial abnormalities, scoliosis, and developmental coxa vara or coxa valga. The reference by Richie et al discusses management options for hip conditions associated with cleidocranial dysplasia. Spondyloepiphyseal dysplasia tarda presents with coxa vara but generally with non-ossified capital femoral epiphyses. Although the radiographs might be confused with SCFE, clavicle dysmorphism is not associated with SCFE. Hypothyroidism can lead to bilateral SCFE or a bilateral LCP type picture, but again is not characterized by clavicle dysmorphism. Renal osteodystrophy would present with bones suggestive of osteomalacia and abnormalities of the epiphysis.Ans1