Pediatrics

4


Pediatrics


Philip McClure, Josh Vaughn, and Craig Eberson


I. Normal Growth/Development (Fig. 4.1), Appearance of Secondary Centers of Ossification, and Chronology of Physeal Closure (Fig. 4.2)


1. Diagram with expected growth rates/ratio (Figs. 4.3, 4.4)


2. Basic rules of growth rates


• Females physes close at ages 14–16


• Males physes close at ages 16–18


3. Annual growth of the leg



• 3, 9, 6, and 3 mm are the average respective growth rates of the lower extremity long bones.


• Proximal femur: 3 mm


• Distal femur: 9 mm


• Proximal tibia: 6 mm


• Distal tibia: 3 mm






4. Can predict effect of epiphysiodesis/premature growth plate closure on leg length


• Effect = Physis rate × Years of growth left (Figs. 4.3 and 4.4)


5. Normal developmental milestones


• 3 months: head control; can lift head off the floor when prone


• 6 months: rolls over


• 6–9 months: sits up without support


• 9 months: crawls


• 12 months: walks with one hand support (cruising)


• 12–17 months: walks independently


• 2 years: ascends stairs and can run forward


• 3 years: rides a tricycle


• 4 years: balances on one foot


• 5 years: hops on one foot



• Handedness develops between ages 2 and 3 years; an earlier preference may be pathological.


II. Pediatric Imaging


1. General


• Assess physeal closure and compare with the contralateral side if needed.


2. Elbow: Baumann’s angle (normal 20 degrees; used to measure varus/valgus in supracondylar fracture), anterior humeral line (should pass through middle third of capitellum); radial head should align with capitellum in all views, though capitellum may not be visible in infants (Fig. 4.5).




3. Cervical spine (Fig. 4.6)


4. Lumbar spine (Fig. 4.7)


5. Hip (Fig. 4.8)


6. Slipped capital femoral epiphysis (SCFE) (Figs. 4.9 and 4.10)


7. Knee: thigh–foot angle, anatomic axis/alignment (Fig. 4.11)


8. Foot: Kite’s angle (Fig. 4.12)



Increased parallelism of the talus and calcaneus constitutes clubfoot.





III. Pediatric-Specific Anatomy


1. Developmental dysplasia of the hip (DDH) (Fig. 4.13)


2. Femoral head blood supply: artery of ligamentum teres plays significant role until age 4


3. Blood supply to epiphysis comes through muscular attachments; no blood vessels cross the physis (Fig. 4.14)







IV. Pediatric Physical


1. Focus on normal growth and development.


2. Limb alignment is often of significant parental concern.


3. All joints should be checked for range of motion; asymmetry or lack of full motion can be the first clue to underlying orthopaedic disease.


• Decreased hip abduction in an infant should prompt evaluation for hip dysplasia.


4. Evaluate ligamentous laxity.


• Recurvatum of knees/elbows


5. Evaluate muscular tone.


• An infant should never “slip through” the examiners hands when placed under the axillae; indicates hypotonia.


6. Neurologic exam


• Some variability exists in resolution of primitive reflexes, but persistence of primitive reflexes should prompt further evaluation.


V. Syndromes with Growth Disturbance


1. Achondroplasia: quantitative defect in proliferative zone resulting in disproportionate dwarfism



• Most common cause of dwarfism is a mutation in fibroblast growth factor receptor-3 (FGFR-3), which results in achondroplasia


• Pathology: autosomal dominant (AD); FGFR3 mutation, 80% spontaneous


• Enchondral ossification more affected than appositional growth


• Presentation: rhizomelic (short limb), hypotonia (results in delayed motor milestones), small nasal bridge with frontal bossing, trident hands, radial head subluxation, frontal bossing, thoracolumbar kyphosis in infancy



• Not prone to early osteoarthritis like pseudoachondroplasia


• Short pedicles and decreased interpedicular distance result in spinal stenosis, which often leads to disability. Foramen magnum stenosis may lead to death. Excessive kyphosis in infancy, often spontaneously resolves. Excessive lumbar lordosis after infancy.


• Imaging: pelvic X-ray shows “champagne glass” with increased width/height ratio; spine with decreased interpedicular distance


• Treatment: neurologic deficit with lumbar decompression/fusion, progressive kyphosis with anteroposterior (AP) fusion (greater than 60 degrees at age 5 if refractory to bracing); lower extremity treatment of angular deformities


2. Pseudoachondroplasia


• Pathology: AD; mutation in collagen oligomeric protein (COMP); normal facies; disproportionate dwarfism


• Presentation: normal facies



• Normal facies and cervical instability are seen in pseudoachondroplasia


• Cervical instability (different from achondroplasia), scoliosis/lumbar lordosis, early osteoarthritis


• Imaging: radiographs demonstrate flaring of metaphysis, and delayed appearance of secondary centers of ossification.


3. Multiple epiphyseal dysplasia (MED)


• Pathology: AD; defect in COMP, or type IX collagen


• Presentation: late-onset dwarfism; MED and spinal epiphyseal dysplasia involve all extremities


• Pulmonary and ocular (retinal detachment) complications common


• Irregular, delayed ossification of multiple epiphyses (similar stage differentiates from Perthes); valgus knees that may require osteotomy for correction


• Imaging: skeletal survey should be obtained to search for multiple sites (coxa vara, valgus knees, early degenerative joint disease).


a. Irregular appearance of epiphysis with late appearance (consider this in differential of bilateral Perthes)



b. Diagnosis is MED if bilateral at same stage, with acetabular involvement; diagnosis is Perthes if asymmetric with normal acetabulum (early)


4. Spondyloepiphyseal dysplasia (SED)


• Pathology


a. Congenital form: AD; defect in type II collagen


b. Tarda form: X-linked; SEDL gene


• Presentation: involves all extremities (like MED) but also involves the spine (scoliosis with sharp curve)


a. Congenital form: cleft palate, platyspondyly


b. Tarda form: kyphosis, hip dysplasia


• Hypoplastic dens may lead to C1-C2 instability.


5. Kniest syndrome


• Pathology: AD; type II collagen defect (COL2A1 gene): osteopenia and dumbbell-shaped bones


• Presentation: short trunk, dumbbell femurs, joint contractures, scoliosis, kyphosis, hypoplastic pelvis/spine


• Often with skull abnormality leading to hearing loss and otitis media


6. Metaphyseal chondrodysplasia


• Normal epiphysis, abnormalities in proliferative and hypertrophic zones of physis


• Waddling gate, genu varum, hyperlordosis, short dwarfism, mental retardation


• Irregular vascular invasion in zone of provisional calcification, resulting in nests of cartilage in metaphysis


Table 4.1 Clinical Characteristics of Metaphyseal Chondrodysplasias




























Jansen


Schmidt


McKusick


PTHrp mutation


Type X collagen


Autosomal recessive


Autosomal dominant


Autosomal dominant


Fine hair


Bulbous metaphyses


Coxa vara/genu varum


Amish and Finnish


Most severe


Often late diagnosis, most common


Atlantoaxial instability


Rare


Proximal femur most striking


Prone to malignancy


• Jansen’s


a. Pathology: AD; parathyroid hormone (PTH) receptor abnormality


b. Presentation: mental retardation, bulbous metaphyseal expansion of long bones, rounded epiphyses, short-limb dwarf


• Schmidt’s


a. Pathology: AD; type X collagen abnormality


b. Presentation: Coxa vara, genu varum



c. Can be confused with rickets but has normal laboratory findings


• McKusick’s


a. Pathology: autosomal recessive (AR)


b. Presentation: small-diameter hair, C1-C2 instability; seen in Amish and Finish population (Table 4.1)


7. Mucopolysaccharidosis (Table 4.2)


• Differentiated by urinary excretion by-product and clinical manifestations



• Associated with carpal tunnel syndrome and trigger finger


• Hunter’s syndrome patients see clearly and shoot toward the X; Hurler’s syndrome patients do poorly; Morquio syndrome patients have spine instability with normal intelligence


8. Diastrophic dysplasia


• Pathology: AR; sulfate transport defect leads to undersulfation of cartilage proteoglycan


• Presentation: severe cervical kyphosis, scoliosis, cleft palate, rigid clubfoot, cauliflower ears, hitchhiker thumb



• Hitchhiker (thumb) lacks adequate (sulfate) transporter.


• Spinal deformity can lead to neurologic defects.


9. Cleidocranial dysplasia



• Leads to absent clavicles


• Pathology: CBFA-1 (RUNX-2) defect (AD)



images

• Presentation: proportionate dwarf, absent clavicles, coxa vara, shoulder hypermobility, skull abnormalities pubic diastasis


• Affects membranous ossification


VI. Syndromes of skeletal muscle


1. Duchenne muscular dystrophy


• Pathology: X-linked recessive; dystrophin protein absent


• Presentation: high creatine phosphatase due to muscle breakdown, proximal muscle weakness predominant (Gower’s sign), calf pseudohypertrophy


• Treatment: knee–ankle–foot orthoses and contracture release can prolong walking (usually lost by age 10 years); wheelchair-dependent in teenage years, death by age 20


a. Steroids may delay progression of disease.


• Scoliosis does not respond to bracing; operative treatment before 30 degrees indicated


a. Operative timing more determined by pulmonary and cardiac status than by curve degree. If pulmonary function test (PFT) < 35% of normal, more likely to require tracheostomy and to fail to wean from vent.


2. Becker muscular dystrophy


• Pathology: X-linked recessive, decreased dystrophin levels


• Presentation: later onset and milder than Duchenne


3. Fascioscapulohumeral muscular dystrophy



• These patients can’t whistle.


• Pathology: AD


• Presentation: scapular winging, inability to whistle; normal creatine phosphokinase (CPK) levels


VII. Syndromes of Collagen/Connective Tissue


1. Ehlers-Danlos syndrome


• Pathology: connective tissue disorder


• Presentation: generalized ligamentous laxity, skin hyperelasticity, pathological collagen defect, poor wound healing, DDH, clubfoot


2. Marfan syndrome



• Optic lens dislocation (ectopia lentis): usually bilateral & superotemporal


• Pathology: AD, defect in fibrillin


• Presentation: tall stature, thin limbs, myopia, dural ectasia, pectus excavatum, superior lens dislocation, cardiac abnormality, ligamentous laxity, aortic dilatation/rupture and mitral valve prolapse, scoliosis


• Cardiopulmonary assessment should be done preoperatively. Order magnetic resonance imaging (MRI) to look for dural ectasia, increased pseudarthrosis rate with spinal instrumentation


3. Osteogenesis imperfecta (OI)


• Pathology: qualitative (type III/IV) defect of type I collagen more severe; quantitative (type I) defect less severe; COL1A1/2 mutation from glycine substitution


• Presentation: prone to fracture, blue sclera, olecranon avulsion fracture pathognomonic, basilar invagination, scoliosis


• Normal fracture healing, but limited remodeling


• Treatment: routine fracture treatment; chronic bisphosphonate administration (may decrease skeletal events and generate multiple radiodense lines)


• Bracing ineffective for scoliosis in OI, operate on angle > 50 degrees


4. Larsen syndrome


• Presentation: multiple dislocated joints, scoliosis, foot deformity, cervical kyphosis (could be lethal), clubfoot, accessory ossification center on calcaneus


• Can also have airway problems, heart valve lesions, aorta, hyperelasticity, hypotonia, late myelopathy


VIII. Neurologic Syndromes


1. Charcot-Marie-Tooth (CMT) syndrome


• Pathology: AD; duplication on chromosome 17 creating mutation of peripheral myelin protein (PMP)-22; diagnose with DNA testing


• Presentation: predominant weakness of distal muscle groups; cavovarus foot deformity (weak tibialis anterior, peroneus longus/brevis) and acetabular dysplasia


2. Friedreich’s ataxia


• Pathology: frataxin gene abnormality (repeat)


• Presentation: onset in preteen/teen years; gait instability (wide-based gait), cardiomyopathy, cavus foot, scoliosis, decreased deep tendon reflexes



• Cardiomyopathy seen in Friedreich’s ataxia, neurofibromatosis (NF), and Holt-Oram syndrome


• Cavus feet seen in Friedreich’s ataxia and CMT, but acetabular dysplasia with CMT


• Loss of α motor neurons


• Death in fifth decade


• Treatment: scoliosis treated at 50 degrees with surgery, bracing ineffective


3. Neurofibromatosis (NF)



• Causes of hemihypertrophy: Proteus, Beckwith-Wiedemann syndrome, Klippel-Trenaunay syndrome, NF


• Pathology: AD; defect in neurofibromin


• Presentation: neurofibromas and café au-lait spots (smooth; coast of California borders)


a. Anterolateral tibia bowing (bracing prior to fracture), pseudarthrosis (debride, fix)



Can see renal abnormalities in NF, Klippel-Feil syndrome


b. Cutaneous neuromas, axillary freckling, Lisch nodule


• Treatment:


a. Check renal ultrasound (US), cardiac echocardiogram, and MRI of spine for other abnormalities.


b. Short dystrophic scoliosis; dural ectasia decreases pedicle size (requires MRI); fuse if any progression or over 40 degrees (may require anterior/posterior in young patient to prevent crankshaft phenomenon); high incidence of pseudarthrosis


• No scoliosis in NF2


4. Spinal muscular atrophy


• Pathology: AR, defect in survival motor neuron gene


• Decreased protein levels in anterior horn cells of the spine cause cell death.


• Presentation: muscle weakness, atrophy; consider if delay or loss of motor milestones, scoliosis


• Electromyogram (EMG) shows fibrillations; muscle biopsy shows denervation.


• Disease severity correlates with ability to produce survival of motor neuron (SMN) protein from the number of functioning SMN II genes remaining (all SMN I genes are nonfunctional in affected individuals).


• Treatment: hip subluxation: treat nonoperatively and keep dislocated; scoliosis, bracing not tolerated


5. Arthrogryposis


• Pathology: decreased anterior horn cells


• Presentation: nonprogressive; myopathic or neuropathic; normal intelligence and facial appearance; multiple joint contractures without skin creases; rigid clubfeet or vertical talus


• Treatment: may require muscle transfers or release; fusions if refractory to soft tissue work alone (triple arthrodesis)


a. Bilateral hip dislocations often left alone (can reduced bilaterally through medial approach in young patients), unilateral dislocation reduced (medial approach)


b. Triceps transfer with posterior elbow release to obtain elbow flexion


c. Knee contractures treated with hamstring lengthening


IX. Other Syndromes


1. Osteochondroses


• Navicular (Kohler’s)


a. Treatment: non–weight bearing with cast for initial treatment


• Scaphoid (Preiser’s)


• Femoral head (Chandler’s)


• Capitellum (Panner’s)


2. Osteopetrosis: AR, defect in carbonic anhydrase


3. McCune-Albright syndrome


• Pathology: Defect in GS-α subunit of cyclic adenosine monophosphate (cAMP) second messenger pathway


• Presentation: polyostotic fibrous dysplasia, precocious puberty, café-au-lait spots (coast of Maine borders)


• Fibrous dysplasia leads to varus proximal femoral deformity (shepherd’s crook deformity); correct with valgus osteotomy


X. Cerebral Palsy


1. Static nonprogressive encephalopathy with progressive manifestations


2. Multiple causes [all with central nervous system (CNS) injury before age 2]


3. Three classification systems with varying criteria (descriptive and severity based) (Table 4.3)


4. Independent sitting by age 2 predicts ambulation; persistence of more than one primitive reflex makes ambulation less likely.


• Moro reflex normally gone by 6 months (pathological if persists longer)


• Parachute reflex normally gone by 12 months (pathological if persists longer)


5. In hip dislocation, posterosuperior quadrant is deficient


6. Highest risk for scoliosis with spastic quadriplegia


7. Treatment:



images

8. Spasticity: Botox, baclofen [γ-aminobutyric acid (GABA) agonist]; transfer of spastic muscles can improve flexible deformities


• Toe walking: if ankle is able to dorsiflex past neutral, stretching and AFO; if unable to reach neutral, consider Achilles or gastroc lengthening


• Crouched gait: multilevel releases


• Stiff knee gait: rectus femoris transfer due to its firing out of phase; hamstring lengthening


• Equinovarus foot: split posterior tibial tendon transfer due to overpull of this tendon (or the anterior tibialis tendon), which can contribute to varus deformity (but not equinus). Achilles tendon is involved and correction is required to address equinus. Address whichever tendon is spastic during stance and swing.


• Hip subluxation: may require adductor release; varus producing osteotomy, acetabuloplasty


a. In young patients, maximize therapy and range of motion prior to releases and lengthenings


b. Hip at risk (age < 5 years) with < 45 degrees hip abduction: adductor and psoas release


c. Hip subluxation: tenotomies with or without femoral or acetabular osteotomies for valgus femoral neck or acetabular dysplasia


d. Spontaneous dislocation: open reduction, varus derotation osteotomy (VDRO), pelvic osteotomy


e. Windswept pelvis: bilateral varus osteotomies of hips


f. Scoliosis: curves with marked pelvic obliquity, require anterior and posterior fusion; spinal fusion indicated for curve > 50 degrees, progressive pelvic obliquity, sitting problems


g. Fusion to pelvis indicated in nonambulatory patients with pelvic obliquity


h. Hallux valgus: orthotics; metatarsophalangeal (MTP) fusion if patient fails conservative management


XI. Birth Injuries and Related Abnormalities


1. Brachial plexus injury (see Chapter 9)


• More common with large babies, shoulder dystocia, forceps delivery, breech position


• No biceps motion at 6 months is a poor prognostic indicator.


• Horner’s syndrome indicates lower trunk root avulsion and poor prognosis.


• Maintain passive range of motion (ROM) while awaiting potential recovery (Table 4.4).


Table 4.4 Classification and Prognosis of Brachial Plexus Injury




















Type


Roots


Prognosis


Complete


C5-T1


Worst


Erb-Duchenne


C5-C6


Best


Klumke


C7-T1


Poor


2. Torticollis


• Pathology: secondary to intrauterine compartment syndrome or positional contracture of the sternocleidomastoid


• Treatment: involves stretching and possible release


• 12—20% associated with DDH


3. Congenital pseudarthrosis of the clavicle


• Can be mistaken for fracture but has resorbed edges


• Enlarging painless mass


• If functional symptoms may treat at age 3–5 with open reduction and internal fixation (ORIF)


XII. Spine


1. Spondylolysis: stress fracture of pars


• Physical exam: pain with lumbar extension


• Imaging: oblique X-ray of questionable utility; computed tomography (CT) and MRI more sensitive; single photon emission computed tomography (SPECT) most sensitive imaging study


• Acute treatment: bracing


• Surgery if refractory versus pars repair


2. Spondylolisthesis


• Pathology: anterior translation of proximal vertebral segment


• Presentation: most common at L5-S1


a. Lytic subtype from spondylolysis


b. Dysplastic from abnormal anatomy, higher progression


• Graded by percentage of anterior translation (quartiles)


• Treatment


a. Low-grade translation treated with brace/therapy


b. Higher grade (3–4) treated with fusion (l4-S1)


c. Return to play with spondylolisthesis


Grade 1: return after pain resolves


Grade 2: no gymnastics or football; slip angle greater than 10 degrees or greater than 30 degree with sacral inclination may progress


Grade 3 and 4: usually cause neurologic symptoms; require prophylactic fusion (posterolateral)


3. Scoliosis (Fig. 4.15 and Table 4.5)


• Indications for MRI: left thoracic curve, thoracic kyphosis, congenital or juvenile disease, rapid progression, child with other syndrome, neurologic abnormality


• General


a. Cervical stability views for Morquio or Down syndromes; cardiology and pulmonary for muscular dystrophy; hematology if associated radial deficiency


• Juvenile


a. Growing rods: indicated if thoracic size needs to increase prior to definitive treatment; increasing force required for subsequent distractions, with less correction obtainable


• Adolescent idiopathic


a. Progression of curve can be minimized with brace wear greater than 12 hours/day (actual wear), (82% successful)



b. Risser stages:


Stage 0: no apophysis visible


Stage 1: anterior ¼ visible


Stage 2: anterior ½ visible


Stage 3: anterior ¾ visible


Stage 4: all visible but unfused


Stage 5: fused


c. Curve progression most rapid at peak height velocity, which occurs during Risser stage 0 and before menarche



• Treatment with anterior-posterior spinal fusion indicated for myelomeningocele, congenital spinal deformity. Relative indications: NF, age < 10 years, > 75-degree curve, Marfan’s syndrome


4. Kyphosis


• Congenital


a. Most commonly from failure of formation of elements


b. Poor prognosis with high incidence of neurologic compromise


c. Treatment of choice is posterior fusion if < 50 degrees; larger or stiffer curves may require anterior/posterior surgery or deformity resection


• Scheuermann’s


a. Pathology: increased kyphosis with > 5 degrees of wedging in three consecutive vertebrae (differentiates from postural kyphosis)


b. More common in males and overweight individuals


c. Bracing if > 50 degrees, but poorly tolerated (Milwaukee brace)


d. Surgery if progressive or continued pain, curve > 75 degrees; anterior surgery rarely needed if pedicle screws used


5. Cervical spine


• Klippel-Feil syndrome


a. Pathology: congenital fusion of cervical spine


b. Presentation: low hair line, limited ROM, short neck


Associated with Sprengel’s deformity (high scapula with limited abduction), renal abnormality.


Treatment: surgery only if neurologic deficit or intractable pain; otherwise, patient avoids contact sports/gymnastics


• Instability (atlantoaxial)


a. Associated with Down syndrome, Morquio syndrome, juvenile rheumatoid arthritis



b. No contact sports/gymnastics


c. Surgery if neurologic defect (fusion)


6. Myelodysplasia


• Caused by incomplete closure of spinal cord, early diagnosis with elevated α-fetoprotein in amniotic fluid (prevent with folate)


• Spina bifida occulta: defect in posterior elements with no herniation


• Meningocele: dural sac without neurologic elements


• Myelomeningocele: dural sac with herniation of neural elements


• Lowest functional level (Table 4.6)


• L5 level generates calcaneus foot, treatment with transfer of anterior tibial tendon (avoid triple arthrodesis)


• Bilateral dislocated hips of L3 or above should be left alone. Position of hips does not contribute to overall functional outcome at the thoracic level.


• Soft tissue contractures should be treated to improve positioning and care.


• Fracture may manifest as warmth/erythema only and is commonly missed, as only minimal energy is required to fracture.


• Increased rate of latex sensitivity


• Severe local kyphosis at level of defect may require excision of the deformity (kyphectomy)



• Rapid progression of scoliosis may be attributable to tethered cord in spina bifida occulta; order MRI.


7. Pseudosubluxation


• Can be normal finding before age 8 years


• Most common at C2-C3, followed by C3-C4


• Alignment of posterior elements remains anatomic


8. Atlantoaxial rotatory subluxation


• May be due to retropharyngeal infection


• Treatment:


a. Presents < 1 week: collar, nonsteroidal anti-inflammatory drug (NSAIDs), physical therapy


b. Presents > 1 week: traction ± halo traction


c. Presents > 1 month: traction ± C1/C2 fusion if unstable or neurologic compromise present


9. Vertebral osteomyelitis


• Enhancement of vertebral body (high on T2) on MRI


• Treatment: obtain percutaneous biopsy and blood cultures


• Appropriate antibiotics are first-line treatment


10. Diskitis



• Primary diskitis is a pediatric disease not seen in adults.

Jun 28, 2018 | Posted by in ORTHOPEDIC | Comments Off on Pediatrics
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