MSK Flashcards
Epiphysis are initially ______
Cartilaginous, converting to bone with development of secondary ossification center
Primary physis is responsible for
Longitudinal growth of the bone
Secondary physis is responsible for
Spherical growth of epiphysis
What are the characteristics of pediatric bone as compared to adults
Less dense, more porous and have lower mineral content compared with adults
Due to pediatric bones characteristics, it can undergo a greater degree of deformation before breaking. Therefore, what fractures are common in pedia population
Greenstick (unicortical) and torus (buckle) fractures, as well as plastic deformation, complete fractures and physeal injuries
In newborn, bone marrow is entirely
Hematopoietic (red marrow)
Bone marrow transformation to fatty (yellow) marrow begins when
Within the first year of life and occurs in a predictable manner
In the body as a whole, marrow transformation begins where
In the periphery, first occurring in the phalanges of the fingers and toes and progressing centrally
Order of fatty marrow conversion of epiphysis, metaphysis and diaphysis
Epiphyses are first to convert, occurring within 6 months of radiologic appearance of secondary ossification center, continues within diaphysis, followed by metaphysis, with the proximal metaphysis the last to convert
On MR, the physis has a ______ appearance
Trilaminar appearance
The trilaminar appearance of physis in MRI consists of:
Zone of cartilage- active chondrocytes;
Zone of provisional calcification- cartilage matrix become calcified;
Primary spongiosa- where woven bone is formed
Fibrocartilaginous structure that surrounds the physeal cartilage, low signal on all sequences. This is tightly tethered to the physis and acts as a barrier to disease
Perichondrium
A thin low SI structure that parallels bone cortex and is loosely attached to the shaft and tightly attached to the perichondrium. Deep to this structure is a rich vascular network that helps to feed the growing metaphyses
Periosteum
This fracture occurs from longitudinal stress and results in bowing of the bones, with an intact periosteum
Plastic deformation
Plastic deformation are common in
Forearm, tibia, fibula
Fractures that results from axial loading on an extremity, occurring at the metaphysis or metadiaphysis. The cortex is compressed and bulges without extension of the fracture to the cortex
Buckle or torus fracture
Represent 50% of pediatric wrist fractures
Buckle fracture
Incomplete fractures resulting from perpendicular forces that break one cortex, the side opposite the site of stress
Greenstick fractures
Most vulnerable to injury during periods of active growth, such as during early adolescence
Cartilage
Weakest portion of the physeal cartilage
Zone of provisional calcification
Pathophysiology of chronic physeal trauma
Repetitive loading can alter metaphyseal perfusion and interfere with the mineralization of hypertrophied chondrocytes
In high intensity runners, chronic physeal injury are common in _____, while in baseball players its common in the ______ which is called little league shoulder and in the _______ in gymnasts (gymnast wrist)
Knees- runners
Proximal humerus- baseball players
Distal radiu- gymnast
Manifests radiographically as widening of the primary physis, with sclerosis at the margins of adjacent metaphysis
Chronic physeal trauma
A subset of physeal injuries (either sequela of trauma, infection or ischemia) can lead to cellular disruption and ischemia, giving rise to the development of abnormal osseous connection (bone bridge or bar) between epiphysis and metaphysis. These bone bars can result in limb length discrepancy, angular deformity, or altered joint mechanics
Physeal bars
The incidence of physeal bar formation is higher after injuries to the
Distal femur, proximal tibia and distal tibia
These areas contribute to the greatest proportion of limb growth, and therefore, bars in these regions have the biggest impact on limb length discrepancies
Distal femur and proximal tibia
Salter harris type: separation thru the physis, usually thru areas of hypertrophic and degenerating cartilage cell columns
1
Salter harris type: fracture thru a portion of the physis that extends thru the metaphyses
2
Salter harris type: fracture theu a portion of the physis that extends thru the epiphysis
3
Salter harris: fracture across the metaphysis, physis and epiphysis
4
Salter-harris type: crush injury to physis
5
Growth centers that serve as the attachment sites for tendons and have a physis at its bone interface
Apophyses
Apophyseal injuries due to repetitive submaximal stress on an apophysis is called ______ Which causes microavulsions at the chondro-osseous junction with resultant secondary inflammatory changes that attempt to repair the physis leading to overgrowth. Manifests radiographically as widenjng and irregulariy at the physis
Traction apophysitis
Little league elbow location of traction apophysitis, due to chronic valgus stress applied to the medial epicondylar apophysis causing medial elbow pain
Medial epicondyle of elbow
Location of traction apophysitis in Sinding-Larsen-Johansson syndrome, resulting from excessive force exerted by the patellar tendon on the lower pole of the patella. Causes anterior knee pain
Inferior patellar pole
Site of traction apophysitis in Osgood-Schlatter disease, pain at the anterior tibial tuberosity due to repetitive traction of the distal patellar tendon on the maturing anterior tibial tubercle
Tibial tuberosity
Location of traction apophysitis in Iselin disease; traction of peroneus brevis tendon on the base of the 5th metatarsal apophysis which presents with lateral foot pain
Base of the 5th metatarsal
Site of traction apophysitis in Sever disease; excessive traction of the Achilles tendon onto the calcaneal apophysis causing heal pain
Calcaneus
Acute apophyseal injuries are common in active adolescents due to
Inherent weakness of apophyseal cartilage
Most common site of pelvic avulsion injuries in adolescents
Ischial tuberosity: hamstrings
Iliac crest muscle/tendon attachment
Abdominal musculature
Muscle/tendon attachment of anterior superior iliac spine
Sartorius, tensor fasciae latae
Muscle/tendon attachment of anterior inferior iliac spine
Rectus femoris muscle
Muscle/tendon attachment of greater trochanter
Hip rotators
Muscle/tendon attachment of lesser trochanter
Iliopsoas muscle
Most common of all pediatric fractures. They may be sen in newborns as a result from birth trauma
Clavicle fractures
Vast majority of clavicle fractures occur in
Middle 1/3 of bone
In children less than 13 years of age, direct impact to shoulder may lead to a physeal fracture of the ______ clavicle, aka periosteal sleeve fracture
Lateral clavicle
Age of the appearance and physeal closure of CRITOE
Capitellum-1 and 14 years
Radial head- 3 and 16 years
Internal (medial) epicondyle- 5 and 15 years
Trochlea- 7 and 14 years
Olecranon- 9 and 14 years
External (lateral) epicondyle- 11 and 16 years
Humerus fractures peaks during adolescence secondary to increased sports participation and are most commonly what type of salter harris fracture
Type 2
In young children, elbow fractures are commonly _______, with a peak incidence if 5-7 years
Supracondylar fractures
Most common mechanism of elbow fractures
FOOSH injury and the hyperextension load
In the normal elbow, the anterior humeral line (line drawn along the anterior cortex of the distal humerus) should bisect the
Middle 3rd of capitellum
In the setting of supracondylar fracture, the capitellum is displaced _____ to the anterior humeral line
Posterior
Have the highest rate of complications among upper extremity fractures
Supracondylar fractures
Complications of supracondylar fractures
Neurovascular compromise, compartment syndrome, Volkmann ischemic contractures and cubitus varus
If the medial epicondyle is displaced greater than ____ mm, fractures require surgical fixation
5 mm
Majority of forearm fractures are located in the
Distal aspect of forearm
Fracture of the ulna and dislocation of the radial head
Monteggia fx
Radial fracture with disruption of the distal radioulnar joint
Galeazzi fx
In older children, the most common carpal bone fx is
Scaphoid fx
Scaphoid fx is important to be recognized due to risk of
Avascular necrosis
Physeal injury of the proximal femur in which the femoral metaphysis displaces anteriorly, superiorly and laterally with respect to the epiphysis
Slipped capital femoral epiphysis
Most sensitive radiographic projection as the slipped epiphysis moves posteriorly and to a lesser extent more medially
Frog leg lateral
Presents as widening and irregularity of the proximal physis, relative loss of height of the epiphysis on the AP projection, loss of anterior concavity of the femoral neck, the metaphyseal blanch sign, and metaphyseal cystic change in chronic cases
Slipped capital femoral epiphysis
It is sign that presents as crescent-shaped area of increased density at the proximal and medial femoral neck as a result of the projection of the posterior portion of the femoral head
Metaphyseal blanch sign
Line drawn along the superior margin of the femoral neck
Kline’s line
In normal hips, the Kline’s line will intersect the _____ aspect of the epiphysis. In SCFE, the epiphysis is displaced ______ and the Kline’s line does not intersect the epiphysis or intersect more ______ compared to the other side
Normal- lateral aspect
SCFE- displaced medially or intersects more laterally compared to the asymptomatic side
Treatment for moderate SCFE
In situ pinning
In more severe SCFE, treatment is
Open reduction with gentle manipulation of the head of the femur back into its normal anatomic location followed by screw fixation
Most common complications following SCFE are
Avascular necrosis and chondrolysis
Occurs when cartilage of the inferior pole of the patella is pulled off from the inferior patellar pole, often with a small avulsed osseous fracture
Patellar sleeve fractures
On radiographs, it may show a small bone fragment inferior to the lower pole of the patella, patella alta and a joint effusion
Patellar sleeve fracture
Seen in children 8-13 y.o and are usually sports-related injuries occuring especially during cycling or skiing
Tibial spine avulsion fractures or tibial eminence fractures
Cause of tibial spine avulsion fracture
Weakness of the incompletely ossified tibial eminence compared to the stronger anterior cruciate ligament
Most common seen in teenage boys and the injury usually involves active extension of the knee with vigorous contraction of the quadriceps muscles, typically in jumping sports
Tibial tubercle fractures
Treatment for fractures confined to the tibial tubercle only
Conservative management
Tibial tubercle Fractures that extend into the epiphysis are treated by
Surgical fixation
Can occur due to axial loading injuries sustained by young children jumping on trampolines or in similar environments such as bounce houses, generally with larger child/adult
Fractures of the proximal tibial metaphsis or “trampoline fractures”
Presents as nondisplaced and non angulated linear or buckle fracture of the proximal tibial metaphysis and can be quite subtle
Trampoline fractures
Nondisplaced oblique fracture of the distal tibia that typically presents in childreb between 1 and 4 years of age
Tibial “toddler’s fracture”
Nature of trauma is usually mild, such as twisting injury from tripping while walking or running or fall from a modest height. Most of the time no history of trauma can be elicited
Distal Tibial toddler fracture
Appears as a faint oblique line crossing the distal tibial shaft terminating medially
Distal tibial toddler fracture
Ogden tibial fx classification: fracture of distal aspect of the tibial tubercle near the patellar tendon insertion
1A
Ogden tibial fx classification: fragment is displaced anteriorly and proximally
1b
Ogden tibial fx classification: fracture extends thru the junction of the ossification of the proximal end of the tibia and tubercle
2a
Ogden tibial fx classification: tubercle fragment is comminuted
2B
Ogden tibial fx classification: fracture extends to the joint and is associated with discontinuity of the joint surface
3A
Ogden tibial fx classification: tubercle fragment is comminuted
3B
Second most common physeal injuries in children. Seen only in adolescents, generally between 10 and 16 years of age, when the physis closes in an aymmetric pattern
Distal tibial transitional fractures, triplane and Tillaux fractures
Distal tibial physeal closure pattern
Centrally and then proceeds in an anteromedial direction, then posteromedially and finally laterally, which predicts the specific injury pattern
Salter 4 fx and have sagittal, transverse and coronal components traversing the physis
Triplane fractures
Isolated fracture to the anterolateral portion of the distal tibial epiphysis, a salter 3 injury. Seen in teenagers nearing skeletal maturity, affecting the only remaining portion of the distal tibial physis
Tillaux fractures
AP radiographs demonstrate a vertical fracture line withjn the distal tibial epiphysus extending laterally. Lateral radiograph will show an avulsed fragment displaced anteriorly
Tillaux fx
Length of displacement of triplane and tillaux fx that would need surgical reduction
More than 2mm
Tibial stress fx usually involve what part
Proximal 3rd of the bone and more common posteriorly
More sensitive modality in detecting stress fx
MRI
These fx are uncommon in active young children however can be seen in adolescents with the so-called “female athlete triad”: osteoporosis, amenorrhea and eating disorders
Insufficiency fx
Important cause of foot pain in the young child
Metatarsal and tarsal bones injuries
Impaction injuries of the hindfoot in toddlers can cause
Nondisplaced or buckle type fx of talus or calcaneus
May occur in young children with forced plantar flexion of the foot, with compression of the cuboid and the 4th and 5th metatarsals
Nondisplaced cuboid fx
Bunk bed fracture, sustained when a child falls or jumps from a height (vertical loading with plantar flexion) and there is buckle injury of the proximal aspect of the metatarsal
First metatarsal fx
Caused by acute injury or repetitive microtrauma that leads to thinning of the articular cartilage, fragmentation of the subchondral bone, and occasionally, loose bodies
Osteochondral lesions
Most common locations for osteochondral lesions
Weight bearing regions of the femoral condyle, capitellum of elbow in throwing athlete and gymnasts, and the ankle
“Bone-cartilage conditions” common in young children and comprise a heterogeneous group of injuries to the epiphyses, physis and apophyses
Osteochondroses
Result from a disturbance in endochondral ossification and are typically self-limited. Rapid growth, genetics, anatomic considerations, trauma, diet and a defect in vascular supply are proposed etiologies
Osteochondroses
Osteochondroses follow a unique series of events, which are:
Necrosis of bone, revascularization, reorganization, with granulation tissue formation and invasion, osteoclast resorption of necrotic segments and ultimately osteoid replacement with mature lamellar bone formed
Common location of osteochondral lesions in the knee
Lateral aspect of medial femoral condyle, weight-bearing surface of medial or lateral femoral condyle, patella, trochlea
Common OCL in the elbow
Capitellum, lateral aspect of trochlea
Common location of OCL in ankle/foot
Medial aspect of talus, lateral aspect of talus, central talar dome, distal tibia, subtalar facet, talar head
Osteochondrosis of the femoral head and is common cause of hip pain and limp in preadolescent children
Legg-Calve’-Perthes disease
Peak age and sex predilection of legg-calve-perthes disease
5-6 years, more common in boys
Most cases of legg-calve-perthes are unilateral or bilateral?
Unilateral
Early in its course of disease, radiographs may demonstrate widening of the medial joint space and asymmetrically smaller femoral epiphysis of the affected side with sclerosis. Physis may become indistinct, lucency may be seen within the femoral metaphysis, overtime the epiphysis may begin to fragment and flatten. Coxa magna of the femoral neck develops
Legg-calve- perthes disease
Prognostic indicators in legg-calve-perthes disease
Extent of osteonecrosis, amount of lateral extrusion, physeal involvement and metaphyseal abnormalities
Radiographic findings indicative of subsequent growth disturbance in legg-calve-perthes disease
Physeal abnormalities and metaphyseal lucencies
True or false: the younger the age of presentation in legg-calve-perthes disease, the more benign the course
True
asymmetrical, circumferential enlargement and deformation of the femoral head and neck.
Coxa magna of femoral neck
Self limiting osteochondrosis of the developing capitellum that affects children younger than 12 years. Most commonly seen in baseball pitches and falls into the spectrum of “little leaguers elbow”
Panner disease
Presumed cause of panner disease
Repetitive chronic impaction injury to the tenuous blood supply of the capitellum
True or false: the entire capitellum is usually involved in panner disease
True
Radiographically, it appears as demineralization of the capitellum with loss of the normally sharp cortical margins, followed by sclerosis and loss of volume and ultimately progressing to frank fragmentation
Panner disease
True or false: the overlying articular cartilage of capitellum is not affected in panner disease
True
Osteochondrosis of the tarsal navicular bone which occurs between 4 and 9 years of age with a higher prevalence in boys
Kohler disease
Sclerosis and narrowing/flattening of the tarsal navicular bone
Kohler disease
Osteochondrosis of the metatarsal head
Freiberg’s infarction
Freiberg’s infarction commonly affects the
Second metatarsal head, followed by the 3rd metatarsal head
On radiographs, it appears as widening of the metatarsophalangeal joint with collapse and sclerosis of the metatarsal head. This may be associated with loose body formation, dorsal spurring and consequent thickening of the metatarsal shaft
Freiberg’s infarction
Non accidental trauma such as skull fractures, rib fractures and displaced metaphyseal injuries predominate at what age
Infancy
Long bone injuries from non accidental trauma predominate at what age
After 1 year of age
Fractures with high specificity for abuse include
Classic metaphyseal lesions, rib fractures (especially posterior), scapular fractures, spinous process fx, and sternal fractures
Aka corner fractures or bucket handle fractures
Classic metaphyseal lesion
Most frequently encountered long bone injury in abused children and are commonly seen in what bones
Distal femora, proximal and distal tibia and proximal humeri
True or false: CMLs may heal without significant callus or subperiosteal new bone formation which makes dating assessment difficult
True
When should follow up skeletal surveys be done in non accidental trauma patients as this will increase the sensitivity of depicting subtle or occult fractures
2 weeks after
3 major pathways of bone infection
Hematogeneous, direct inoculation and via extension from adjacent soft tissue infections
In children, acute osteomyelitis is most commonly acquired _______
Hematogeneously
Most common organisms involved in osteomyelitis in children
Staphylococcus aureus, B-hemolytic streptococcus and streptococcus pneumoniae, E.coli and pseudomonas aeruginosa
Acute hematogeneous osteomyelitis primarily involves the
Metaphyses of long bones or metapgyseal equivalents (osseous regions adjacent to a physis)
Metaphyses of long bones are common site for acute hematogeneous osteomyelitis due to
Presence of slow-flowing venous sinusoids
Complications of acute osteomyelitis
Subperiosteal abscess and ultimately dissecting into the adjacent soft tissues, thrombophlebitis, septic emboli, growth arrest due to bone bar formation, pathologic fx and chronic osteomyelitis
Most cases of epiphyseal osteomyelitis or chondritis occur in children of what age
Younger than 4 years
Epiphyseal osteomyelitis or chondritis are best demonstrated as
Avascular/non enhancing regions of affected cartilage
Thrombophlebitis as a complication of acute osteomyelitis is typically associated with
Methicillin resistant S. Aureus
Caused by hematogeneous bacterial seeding or by direct extension into the joint space in the setting of osteomyelitis or adjacent soft tissue infection
Septic arthritis
In very young infant, septic arthritis present as multifocal involvement, with the ____ as the most frequent site
Hip
True or false: imaging cannot reliably differentiate a reactive effusion (toxic synovitis) from septic arthritis
True
A self-limited disease with no known long term sequela. It is a common entity, particularly involving the hip in young children between 3 and 10 years of age. Children appear nontoxic and present with pain and limp and are usually afebrile with normal to marginally elevated WBC and inflammatory markers. Parents often report a preceding viral or bacterial upper respiratory or GI illness (within 4-5 weeks)
Toxic synovitis or transient/reactive synovitis
Treatment for toxic synovitis or transient/reactive synovitis
Rest and analgesics and symptoms begin to resolve within 24-48 hours
Very common benign tumor/tumor like lesion of bone and occur in approximately 1-2% of population. Thought to represent a developmental defect of bone growth secondary to an injury to the perichondrium, rather than a true tumor
Osteochondroma
Condition in which physeal cartilage herniates through this defect and growth results in an osseous excrescence with continuity to the underlying medullary canal and cortex, with an overlying cartilagenous cap
Osteochondroma
Most commonly affected part in osteochondroma
Lower extremity, commonly in the knee
Radiographic hallmark of an osteochondroma
Osseous excrescence with continuity of the cortex and medullary space from the underlying bone into the osteochondroma
When the osteochondroma is pedunculated, the lesion usually points where
Away from the nearest joint
If the cartilageneous cap of osteochondroma is ____ cm in thickness, the very rare transformation to chondrosarcoma should be considered
More than 1.5 cm
Multiple osteochondromas are seen in patients with
Hereditary multiple exostoses or familial osteochondromatosis or diaphyseal aclasis
A distinct disorder secondary to osteochondroma development from an epiphysis that predominantly affects the lower extremities
Trevor disease or dysplasia epiphysealis hemimelica
Uncommon benign cartilaginous neoplasms that characteristically arise eccentrically in the epiphyses or apophyses of children, with 70% occurring in the humerus, femur and tibia
Chondroblastoma
Well-defined lucent lesions with smooth or lobulated borders and a thin sclerotic rim with perhaps endosteal scalloping
Chondroblastoma
Treatment of chondroblastoma
Curettage and packing of the lesion or radiofrequency ablation
Disorder resulting from the proliferation and accumulation of the Langerhans cell, a histiocyte. Cause is unknown altho some studies suggest abnormal immune regulation as the underlying factor and others consider it a neoplastic process
Langerhans cell histiocytosis
Localized form of LCH usually presents in children age
10 to 12 y.o
LCH can involve any bone, however there is a predilection for
Flat bones and more than half of the lesions in localized LCH occur in the skull, mandible, pelvis and ribs
When there is long bone involvement, LCH usually occurs within the _____ with the ______ being the most common long bone site
Diaphsysis and femur
Mandibular involvement in this condition may lead to floating tooth appearance due to the destruction of alveolar bone
Langerhans cell histiocytosis
Management of langerhans cell histiocytosis
Curettage, ablative techniques and direct intralesional methylprednisolone injection, disseminated disease may be treated with steroids and chemotheraphy
Most common malignant primary tumor in children and young adults
Osteosarcoma
Gender predominance and age of peak incidence of osteosarcoma
Male, 15-25 years of age
Types of osteosarcoma
Intramedullary, surface, extraskeletal and secondary osteosarcoma
Most common type of osteosarcoma and is referred to as conventional osteosarcoma
High-grade intramedullary type
These osteosarcomas arise from the medullary cavity of the metaphysis of long bones, most commonly in the distal femur and proximal tibia
High grade intramedullary osteosarcoma
Typically appears as a mass that contains fluffy, cloudlike opacity which represents osteoid matrix production. Lesions usually have a mixed lytic and sclerotic appearance with cortical erosion and destruction. Given the aggressive growth pattern, there is often spiculated (sunburst) periosteal new bone and periosteal elevation is frequently seen resulting in Codman triangles
Osteosarcoma
Skull lesions appear as beveled edge or “hole in hole” appearance due to unequal involvement of the inner and outer tables of the calvarium
Langerhans cell histiocytosis or eosinophilic granulomatosis
An uncommon subtype of intramedullary osteosarcoma and is often confused with aneurysmal bone cysts
Telangiectatic osteosarcoma
Type of osteosarcoma that tends to occur around the knee and contains large cystic cavities filled with blood or necrotic tumor, and the walls/septations contrain malignant cells that produce osteoid
Telangiectatic osteosarcoma
Most common surface osteosarcomas
Parosteal and periosteal subtypes
Most common type of surface osteosarcoma and tends to occur in older patient population
Parosteal subtype
Intermediate-grade osteosarcoma lesions which are thought to arise from the deep layers of the periosteum and arise in patients of the same age as conventional osteosarcoma
Periosteal osteosarcoma
Type of osteosarcoma that tend to arise in the diaphysis with the femur and tibia representing the most common location
Periosteal osteosarcomas
Treatment of osteosarcoma
Combination of chemotherapy and surgery
True or false: osteosarcoma is not radiosensitive
True
Small, round, blue cell tumor of childhood and belongs to the family of tumors including extraosseous Ewing sarcoma, Askin tumor and primitive neuroectodermal tumors (PNET)
Ewing sarcoma
Second most common primary malignant bone tumor in children and adolescents with an annual incidence of approximately 200 cases
Ewing sarcoma
Ewing sarcoma is most frequent in the ____ decades of life, with peak incidence between what age
3 decades of life, peak between 10-20 years of age
Gender predominance of ewing sarcoma
Male
True or false:ewing sarcoma is uncommon in african-american and asian populations
True
Ewing sarcoma most commonly occurs in what bones
Extremities, ribs and pelvis
Most commonly involved bone in ewing sarcoma
Femur
Ewing sarcoma Lesions in long bones typically arise in the
Metadiaphysis and diaphysis
Has an aggressive appearance with bone destruction leading to a moth-eaten or permeative pattern. There is usually periosteal reaction which may appear lamellated (onion-skin like). An associated soft tissue mass is also a common finding and the mass tends to be much larger in size in comparison to the amount of underlying bone destruction
Ewing sarcoma
Most common malignancy of children
Acute leukemia
Most common type of leukemia
Acute lymphoblastic leukemia
Peak incidence of ALL
2-3 years of age
Most common skeletal finding in leukemia
Diffuse demineralization
So called “leukemic lines” seen in 50% of patients with skeletal findings. They are non specific and seen as a uniform and regular lucency across the width of metaphysis in those bones associated with rapid growth such as the distal femurs, proximal tibia/humeri, vertebral bodies and iliac crests
Transverse lucent metaphyseal bands
Benign vascular tumors and is the most common vascular tumor of infancy
Hemangioma
Vascular lesion that follows a characteristic clinical pattern:they are not present at birth, although sometimes a precursor lesion such as discoloration or macule may be present. There is rapid growth after birth during the proliferative phase, with a peak at about 1 year of age. An involuting phase follows with spontaneous regression and decrease in size over many years. Final stage is a fibrotic stage with small residual fibrofatty tissue remaining for life
Hemangioma
Most commonly involved organ in infantile hemangioma
Skin followed by the liver
Infanfile hemangioma are associated with what syndromes
PHACE sydrome (posterior fossa brain malformations; hemangiomas of the face, neck or scalp;arterial anomalies; coarctation of the aorta and cardiac defects; and eye abnormalities) LUMBAR syndrome (lower body infantile hemangiomas, urogenital anomalies, ulceration, myelopathy, bony deformities, anorectal malformations, arterial anomalies and renal anomalies)
Congenital hemangiomas can be distinguished from infantile hemangiomas clinically as they at birth because of the
Proliferative phase occurs in utero
Primary diagnostic imaging modality for hemangiomas
Ultrasound
Spectral doppler of hemangiomas will show
Low resistance arterial waveforms
On color doppler imaging, hemangiomas appear as
Marked vascularity with 5 or more vessels per square centimeter
As hemangiomas involutes, it will appear
Show decreased vascularity and increased echogenicity
Of note, this should not be present in hemangiomas
Perilesional edema
Treatment for hemangioma
No tx required unless for loss of function or cosmetic issues, medical tx with propanolol and possibly embolization or surgery may be performed
Aka pseudotumor of infancy or sternomastoid pseudotumor.
Fibromatosis coli
Usually manifests at about 2 weeks of life with a palpable mass in the sternocleidomastoid muscle
Fibromatosis colli
Fibromatosis colli is usually unilateral or bilateral?
Unilateral
True or false: fibromatosis colli is more commonly right-sided and can cause torticollis
True
Majority of cases of fibromatosis colli resolve by what age
2 years of age
Treatment for fibromatosis colli
Conservative: stretching and physical therapy
Heterogeneous group of disorders which are characterized by abnormal bone and cartilage growth
Skeletal dysplasias
Long bone dysplasias affecting the proximal portions of extremities
Rhizomelia
Dysplasias affecting the middle portion of long bones
Mesomelia
Dysplasias affecting the distal portion of long bones
Acromelia
Shortening of the entire extremity
Micromelia
Most common non lethal skeletal dysplasia and patients have normal mentation and life span
Achondroplasia
Patients have rhizomelia, frontal bossing and small/narrow foramen magnum, thorax is small with shortened ribs, narrowing of rhe interpedicular distance particularly in the more caudal segments of lumbar spine and posterior vertebral body scalloping and gibbus deformity. Iliac wings may be rounded, with flat acetabular roofs, narrow sacrosciatic notches and a champagne glass-shaped pelvic inlet, hands show brachydactyly with trident configuration. Femurs show scooped out appearnce while the distal femur has a deep notch in the central growth plate (chevron deformity) and there is fibular overgrowth
Achondroplasia
On of the most common lethat skeletal dysplasia, with features such as “clover-lead” skull due to craniosynostosis, curved long bones including “French Telephone reciever” appearance to the femurs, platyspondyly, short rivs and handlebar clavicles and micromelia
Thanatophoric dwarfism
Presence of this can help distinguish thanatophoric dwarfiam from other forms of dwarfism
Platyspondyly
Group of metabolic disorders that involve the defective activity of the lysosomal enzymes which blocks degradation of mucopolysaccharides. Most commin subtypes are Hunter, Hurler, Sanfilippo and Morquio syndromes
Mucopolysaccharidoses
Common features include enlarged skull with J-shaped sella, paddle or oat-shaped ribs, beaking of the thoracolumbar vertebral bodies sometimes with gibbus deformity. Iliac wings are flaired and small with inferior tapering and steep acetabular roofs. Metacarpals show proximal tapering
Mucopolysaccharidoses
Inherited disorder of connective tissue characterized by increased bone fragility and low bone mass. Clinical findings include blue sclera, dentinogenesis imperfecta, skin hyperlaxity and joint hypermobility
Osteogenesis imperfecta
Most common type of osteogenesis imperfecta
Mild type 1 disease
Main radiographic features include diffuse demineralization, fractures and deformities. Fx typically invloves the long bones and spine. Popcorn calcifications are also described at the metaphsysis/epiphysis which are secondary to ossification of the displaced and fragmented physis
Osteogenesis imperfecta
Rare bone disease that results from a failure of osteoclasts to resorb bone. Decreased osteoclastic activity leads to decreased elasticity of bone, impaired repair functions and increased risk of fx. Greater risk of infection and delayed union
Osteopetrosis
Hallmark of osteopetrosis
Increased density in the medullary portion of bone with relative sparing of the cortices
Type of osteopetrosis that has uniform sclerosis of the long bones, skull and spine
Phenotypic variant Type 1
Type of osteopetrosis that has a the “bone-within-bone” appearance and sclerosis of the skull base
Phenotypic type 2
Sandwich vertebra or picture frame vertebral bodies
Phenotypic type 2 osteopetrosis
Relatively common dysplasia findings and include: wide sutures, numerous wormian bones, absence/hypoplasia of clavicles and pubic bones, posterior wedging of thoracic vertebral bodies, numerous pseudoepiphyses of metacarpals and tapered distal phalanges
Cleidocranial dysplasia
Aka infantile cortical hyperostosis and is characterized by presentation before the 5th month of life, hyperirritability, soft tissue swelling and bone lesions, particularly mandible involvement
Caffey disease
Long bones, clavicle, scapulae and ribs can also be involved and demonstrate diaphyseal new bone formation sparing the epiphyses and metaphyses
Caffey disease
True or false: caffey disease is a self-limiting process with bone remodeling and resorption occurring by age 2
True
Aka von Recklinghausen disease, an autosomal dominant disorder due to mutation or deletion of NF1 gene
NF1
Chromosome involved in NF1
17
Characterized by formation of neurofibromas and abnormalities related to mesodermal dysplasia
NF1
Most common complication of NF1
Spinal deformities, particularly scoliosis
Imaging characteristics include vertebral scalloping, neuroforaminal widening, transverse process spindling and rib penciling
NF1
Posterior vertebral scalloping aside from NF1, can also be seen in
Marfan syndrome, achondroplasia and associated with spinal tumors
Posterior vertebral scalloping in NF1 is due to
Bone weakness and circumferentual dilation of dural sac
May be one of the earliest manifestations of NF1, typically presenting within the first few years of life
Tibial bowing
Tibial bowing in NF1 is usually at what direction
Anterolateral, tends to involve the distal diaphysis, resulting in limb shortening
Benign positional bowing of tibia is directed
Posteromedially
Characterized by impaired mineralization and ossification of cartilage and osteoid and delayed endochondral ossification in children. Results in excessive physeal cartilage, growth failure and skeletal deformities. Risks include exclusively breastfed infants and African americans
Rickets
Patients with this condition manifest short stature, failure to thrice, weakness and bowing deformities
Rickets
Earliest manifestation of rickets
Demineralization
Findings in rickets are most prominent in what areas
Metaphyses of bones with the greatest growth: distal radius and ulna, distal femur, proximal tibia, proximal humerus and anterior rib ends
One of the earliest changes at the physis in rickets is the
Loss of the zone of provisional calcification
Seen in rickets due to accumulation of unossified cartilage
Widening, fraying and cupping of metaphysis
True or false: distal ulnar metaphysis may normally appear cupped and should not be mistaken for rickets if the distal radial metaphysis appears normal
True
Following vitamin D supplementation in rickets, changes of healing can be seen on radiographs within how many months
2-3 months, with mineralization of the zone of provisional calcification representing one of the earliest findings
Due to a chronic deficiency of vitamin C, which is required for proper biosynthesis of collagen
Scurvy
Pathophysiology of scurvy
Abnormal collagen production leading to vascular fragility along with abnormal bone matrix which occurs in the same areas of greatest bone growth as seen in rickets
Classic signs of scurvy
Frankel line, trummerfeld zone or scurvy line, pelkan spur and wimberger ring sign
Classic scurvy sign with irregular growth plate with a dense band along the metaphyseal side at the zone of provisional calcification. Peripheral extension of this line results in a pointed, “beaked” contour of the metaphysis
Frankel line
Lucent line adjacent to the Frankel line, more diaphyseal in location is known as the ______ which represents accumulated hemorrhage
Trummerfeld zone or scurvy line
A healing metaphyseal pathologic fracture seen as a density adjacent to the metaphysis in scurvy
Pelkan spur
A thin scleroric cortex surrounding a lucent epiphysis in scurvy
Wimberger ring sign
Altho radiographic findings in scurvy are non specific, these findings when present should raise suspicion for scurvy
Diffuse symmetric bilateral metaphyseal changes with adjacent soft tissue edema and periosteal reaction
Most common form of heavy metal poisoning
Lead poisoning
Lead lines is due to
Lead ion deposition in the zone of provisional calcification
Pathophysiology of lead poisoning
Inhibits osteoclastic remodelling but does not affect osteoblasts and results in increased thickness and trabeculae
Difference between lead lines and normal variant dense metaphyseal bands
Lead lines can be distinguished clearly from the zone of provisional calcification once interval growth has occurred, whereas normal variant dense metaphyseal bands are always contiguous with the zone of provisional calcification
Congenital disorder which ranges from hypoplasia to complete absence of proximal femur
Proximal focal femoral deficiency
Associated deformities with proximal focal femoral deficiency
Fibular hemimelia (up to 80%), shortened tibia, hypoplastic patella, agenesis of the cruciate ligaments, deficiency of lateral rays of the foot, talocalcaneal coalition and equinovalgus or equinovarus deformity
Condition with excessive medial bowing of tibia, tibia vara. Result of abnormal stresses on the posteromedial proximal tibial physis, leading to delayed endochondral ossification of the medial physis. This results in asymmetric growth and varus angulation
Blount disease
Most common type of blount disease and is diagnosed before 4 years of age
Infantile
True or false: there is an association between increased body weight and blount disease
True
Diagnosis is made on standing radiographs of lower extremities, genu varum is present as measured by the angle of intersection of lines along the midshaft of femur and tibia. There is depression, irregularity, fragmentation and beaking of proximal medial tibial metaphysis and deficiency of medial proximal tibial epiphysis
Blount disease
Characteristic of Blount disease that will distinguish it from physiologic bowing
Unilateral and asymmetric
Tx for blount disease
Surgical with hemiepiphysiodesis and guided growth with osteotomy
An abnormal fibrous cartilaginous or bony connection between 2 of the tarsal bones
Tarsal coalition
Most common tarsal coalitions
Talocalcaneal and calcaneonavicular
True or false, tarsal coalitions are bilateral in 50% of cases
True
Calcaneonavicular coalitions are best seen on what view
Oblique view
Anteater’s nose sign: elongated appearance of anterior-superior calcaneus extending toward the navicular is seen in
Calcaneonavicular coalition
Foot is is fixed in adduction, supination and in varus. Calcaneus, navicular and cuboid bones are medially rotated relative to the talus. Forefoot is pronates in relation to the hindfoot which gives rise to pes cavus
Congenital talipes equinovarus (clubfoot)
Talocalcaneal coalitiona on lateral radiographs
Talar beaking, poor visualization of talocalcaneal joint space, rounding of lateral talar process and lack of depiction of the middle facet on lateral radiographs
C-sign can be seen on lateral radiographs as well as C-shaped line that outlines the medial talar dome and posterior-inferior sustentaculum
Talocalcaneal coalition
Treatment for coalitions
Casting, physical therapy, orthotocs, anti-inflammatory medications
Four features in weight bearing radiographs of club foot
Hindfoot equinus with a lateral talocalcaneal angle less than 35 degrees, hindfoot varus on AP radiographs with a talocalcaneal angle of less than 20 degrees, metatarsus adductus with adduction and varus deformity of forefoot and talus to first metatarsal angle greater than 15 degrees, as well as medial subluxation of rhe navicular on talus
Lateral view appearance of clubfoot
Near parallel arrangement of talus and calcaneus
Includes a spectrum of abnormalities ranging from mild to markedly abnormal development of femoral head and acetabulum
Developmental dysplasia of hip
What side of the hip is more commonly involved in DDH
Left
Risk factors for DDH
Breech position in utero, oligohydramnios, family hx, female gender, first born
Hip click or clunk with upward force and adduction at the hip in DDH
Ortolani test
Hip click or clunk in downward force and adduction in young infants
Barlow test
Primary imaging modality in screening for and evaluating DDH in children younger than 6 months of age
Ultrasound
A normally positioned hip is how many percent covered by acetabulum
More than 50%
Angle formed by the cortex of the ilium and acetabular roof
Graf alpha angle
Normal alpha angle in hip
More than 60 degrees
In older infants, AP radiographs of pelvis in neutral position allows for
Morphologic assessment of hips
In older infants, frog leg lateral view can help determine
Whether a subluxated hip reduces
Radiograph findings in DDH
Delayed femoral head ossification, shallow acetabulum, abnormal position of femoral head relative to the acetabulum
Treatment of DDH for patients up to 6 months
Closed reduction with Pavlik harness
Treatment of DDH in older infants
Closed surgical reduction with hip spica casting
Excessive abduction in DDH tx is postulated to lead to
AVN
Caused by traction injury during birth leading to brachial plexus palsy
Shoulder dysplasia
Risk factors for shoulder dysplasia
Shoulder dystocia, breech presentation, forceps delivery and fetal macrosomia
Asymmetrically small, aspherical and flattened humeral head. The glenoid will appear dysplastic with a hypoplastic scapula and there is glenoid retroversion
Shoulder dysplasia
Horizontal line thru both triradiate catilages
Hilgenreiner line
In hilgenreiner line, femoral head should line where
Within the inferior medial quadrant of the acetabulum
Vertical line intersecting the lateral rim of the acetabular roof, drawn perpendicular to Hilgenreiner line
Perkins line
C-shaped line along the inferior aspect of pubic ramus and continuing to the inferior border of the femoral neck
Shenton line
Angle formed by a line through the acetabular roof and Hilgenreiner line
Acetabular angle
In neonates, acetabular angle should be,
Less than 30 degrees and decreased as the patient ages, to less than 22 degrees at 1 year of age and older
Angle formed from a vertical line through the center of the ossified femoral head and line along the lateral margin of the acetabular roof
Anterior-center edge angle
Center-edge angle less than 20 degrees us indicative of
DDH
Treatment of shoulder dystocia
PT and botulinum toxin injection or closed reduction
Treatment of shoulder dystocia in older children
May require surgery and nerve grafting may be performed in those with multiple nerve root avulsions
Aka constriction band syndrome comprises a wide range of congenital anomalies where fetal parts get entrapped with fibrous bands if disrupted amnion which typically leads to limb and digital amputations and contriction rings
Amniotic band syndrome
Amniotic band syndrome is caused by
Vascular insult that occurs during
early embryogenesis
An umbrella term that encompasses all forms of inflammatory arthritis that begin the age of 16, persist for more than 6 weeks and are of unknown etiology
Juvenile idiopathic arthritis
Hallmark feature of all subtypes of JIA
Joint inflammation
Pathophysiology of JIA
Inflammation of synovial lining, synovial hyperplasia with increased vascularity, resulting in a high cellular inflammatory pannus, pannus will eventually erode into the overlying cartlage and bone as a result of antibody deposition and degradative enzymes, leading to articular destruction
Role of ultrasound jn JIA
Assess bone surface, for rapid and inexpensive method for evaluating synovial proliferation, joint fluid, cartilage thickness, cortical erosions, tenosynovitis and enthesitis
Best noninvasive imaging modality to evaluate for inflammation of the joints, tendons and entheses in JIA. Useful in assessment of bone marrow edema as well as assessment of intra-articular structures that cannot be accessed with an ultrasound probe
MRI
Goal of intervention for JIA
Suppress synovial and entheseal inflammation in order to prevent cartilage and bone damage
Treatment for JIA
Both systemic therapy as well as direct medicinal joint injections
X-linked congenital bleeding disorders caused by the absence or decrease of clotting factor VIII OR IX
Hemophilic arthropathy
Most frequent manifestation of hemophilic arthropathy
Joint bleeding
One of the earliest complications of hemarthrosis
Synovitis
Synovitis is characterized by
Synovial hypertrophy and inflammation with neoangiogenesis and subsequent bleeding
Commonly involved joints in hemoarthropathy
Knee, elbow, ankle, hip and shoulder
Classic findings in hemarthropathy of the knee
Widened intercondylar notch, squared margins of patella, bulbous femoral condyles with flattened surfaces
Classic findings in elbow hemarthropathy
Enlargement of radial head with a widened trochlear notch
Findings in ankle hemarthropathy
Ankle deformity may arise due to undergrowth of the lateral aspect of distal tibial epiphysis
Idiopathic inflammatory disorder of children and young adults that is characterized by exacerbations and remissions of nonbacterial osteomyelitis
Chronic recurrent multifocal osteomyelitis
CRMO may be seen in conjunction with what other inflammatory conditions
Psoriasis and IBD
Treatment for CRMO
anti-inflammatory therapies
True or false, CRMO remains a disease of exclusion since there is no laboratory confirmation test
True
Characteristic locations of CRMO
Mandible, medial aspect of clavicle, metaphysis of lower extremities, rib, vertebral, sacroiliac joint and pelvic (metaphyseal equivalents
Group of genetic disorders that posses an abnormality within the hemoglobin molecule
Hemoglobinopathies
2 most clinically relevant hemoglobinopathic conditions within the pediatric population
Sickle cell disease and beta thalassemia
Results from a single point mutation in the beta chain of the hemoglobin molecule. This causes the hemoglobin molecules to become sticky with abnormal polymerization, deforming the rbc into classic sickle shape, resulting in microvascular occlusion and ischemic events
Sickle cell disease
Sickle cell patients maintain red marrow in the majority of
Axial and appendicular skeleton, including ankles and wrists
Can cause widened medullary spaces, thinned cortices, demineralization and coarsened trabecular pattern in sickle disease
Red marrow persistence in sickle disease
“Hair on end” pattern in the skull, which appears as widening of the diploic space of calvarium and thinning of the inner or outer calvarial table
Sickle cell disease
progressive cortical thinning and smooth biconcavity may develop in the vertebral bodies due to weakened bone and pressure effect from the adjacent disc in sickle cell disease
Codfish vertebrae
Sharper depressions in the central portions of the endplates due to focal infarction can be seen in sickle cell disease causing this appearance of vertebrae
Lincoln log or H-shaped vertebral bodies
Sickle cell dactylitis or “hand-foot” syndrome will affect approximately how many percent of pediatric patients with majority of patients are at what age
50% of pediatric patients, 6 months to 2 years of age
Areas particularly prone to infarction in sickle cell disease
Small tubular bones of hands and feet
Why is painful crisis in sickle cell dactylitis late to manifest
In these bones, the transformation of red marrow to yellow marrow occurs much later in sickle cell patients, making episodes uncommon after 6 years of age
A characteristic serpiginous “double line” is described which consists of a hyperintense inner line (inflammatory response) and a hypointense outer border (reactive bone interface) in long bones of patients with sickle cell disease. Cortical infarctions can also occur, resulting in cortical thickening or “bone-in-bone” appearance secondary to layered subperiosteal new bone formation
Sickle cell osteonecrosis
Sickle cell-related epiphyseal osteonecrosis is most common in what areas
Humeral and femoral heads and often bilateral
Later stage of epiphyseal infarction include what radiographic findings
Crescentic subchondral lucency and articular irregularity and subchondral collapse and fragmentation
Later stage epiphyseal infarctions in sickle cell disease are often more pronounced in weight-bearing joints such as the
Hip, where articular deformity may lead to secondary degenerative changes
Osteomyelitis in sickle cell patients is usually due to what organisms
Salmonella, or other gram negative organisms such as E. Coli
Genetic disorders affecting the Beta-globin gene that result in reduced or absent synthesis of beta globin chains, ultimately affecting erythropoiesus and red cell lifespans, resulting to anemia, hepatosplenomegaly, cardiomegaly with CHF and significant marrow expansion with secondary osseous deformities
Beta thalassemia
Osseous imaging findings in beta thalassemia are due to
Extramedullary hematopoiesis as well as a result of iron chelation therapy which is distinctly compared with sickle cell disease
In this blood condition, osseous changes occur due to severe anemia and a massive increased demand for rbc which produce diffuse marrow expansion of the calvarium, spine, pelvis and nearly all tubular bones
Beta thalassemia
Diffuse marrow expansion in beta thalassemia results in these radiographic findings
Cortical thinning and resorption of cancellous bone with coarsening of trabecular markings
Commonly involved bone in beta thalassemia
Ribs; expansion of head and neck of ribs
Calvarial thickening in beta thalassemia is most prominent in what part
Frontal bones with thinning of outer table and prominent subperiosteal spicules, creating hair on end appearance
Pathognomonic facial appearance of thalassemia due to marked marrow expansion in calvarium causing diminished pneumatization of paranasal sinuses. Marrow expansion in the maxillary bones may ventrally displace the central incisors and laterally displaces the orbits
Rodent facies
True or false: thalassemia patients who have not undergone transfusion therapy demonstrate an infantile marrow distribution
True
In thalassemia patients receiving transfusions along with chelation therapy, iron deposition will be predominantly within the ______ skeleton with hematopoietic marrow in the remainder
Axial skeleton
