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36 Cards in this Set
- Front
- Back
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Normal variants (common) in the peds skeleton
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-Apophyseal irregularity: Separate ossicles can mimic fragments, irregularity can mimic periosteal reaction, and mixed sclerosis and lucency can be confused with findings of an inflammatory or neoplastic process.
-Common apophyses with this appearance include the tibial tuberosity, ischeal tuberosity, ishial pubic synchondrosis (can be very asymmetric and prominent), and posterior calcaneal apophysis (can be very sclerotic) -Distal femoral metaphyseal irregularity: cortical desmoid. Posteromedial aspect of the distal femoral metaphysis. On frontal xrays, there may be an associated lucency. Often bilateral. On CT: a characteristic scooplike defect with an irregular but intact cortex; no associated soft tissue mass, and sometimes a subtle contralateral lesion. -NOFs (fibrous cortical defect under 2 cm): 40% of children. Most common between 5-6 yrs of age. Most commonly around the knee, particularly the distal femur. Lucent, eccentric, well defined lesions with thin cortical rims. |
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Fractures in Peds
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-Children's bones are softer
-Incomplete fractures are more common in children. -May be a bowing fracture, or associated with buckling of the cortex on the concave margin (torus fracture), or may have an incomplete fracture along convex margin (greenstick fracture) -Buckle fractures may only appear as an increase in acute angulation of a normally gentler curve! -Younger children heal quickly -Periosteal reaction should be expected within 7-10 days. -Children tend to heal completely |
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Salter Harris fractures
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-Physeal involvement may result in growth arrest of a limb, and in a higher rate of internal fixation.
-1: Only the physis. Tends to be under 5 yrs. Epiphysis may be displaced. Often, only appearance is soft tissue swelling -2: Involve the physis and metaphysis, not the epiphysis. Most common type! (75%) -3: Involve the physis and epiphysis but not the metaphysis. Have a greater predisposition for growth arrest. -4: Involve the physis, epiphysis, and metaphysis. High rate of growth arrest -5: Involve a crush injury to part of or all of the physis. -Posttraumatic growth arrest may be seen as a bony bridge across the physis. |
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Wrist fractures
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-Most common fracture site in children
-Most are buckle or transverse fractures of the distal radius -Distal radius also the most common area of physeal fracture -Look for pronator fat pad (obliterated/convex is abnormal) |
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Elbow fractures
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-supracondylar most common (FOOSH)
-anterior humeral line no longer bisects the middle third of the capitellum. -Fracture line usually seen through the anterior cortex of the distal humerus on the lateral view -elbow effusion usually present -traumatic injury to the elbow is treated by splinting, whether a subtle fracture is identified or not. -Other fractures include the lateral condyle, and avulsion of the medial epicondyle (Little League elbow). -Always look at the radiocapitellar line on 2 views!!! (for dislocation of the radial head) |
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Toddler's fracture
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-nondisplaced oblique or spiral fracture of the midshaft of the tibia
-refusal to weight bear -oblique views often better show the fracture -Toddlers can get similar types of fractures involving the proximal anterior tibia, calcaneus, or cuboid (also called toddler's fractures) -The buckle fracture of the proximal tibia is the MOST commonly missed fracture!!!!! |
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Avulsion fractures in adolescents
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-don't touch lesions!
-iliac crest (transversalis, internal oblique, external oblique) -ASIS (sartorius) -AIIS (rectus femoris) -ischial apophysis (hamstrings: biceps femoris, gracilis, semimembranosus, semitendinosus) -lesser trochanter (iliopsoas) -radiographic findings include displacement of the apophysis and variable, often exuberant periosteal new bone -Sinding-Larsen-Johansson syndrome: chronic avulsion of the patellar tendon at its attachment to the patella. Most common in 10-14 yrs of age. Irregular bony fragments at the inferior margin of the patella associated with adjacent soft tissue swelling and thickening and indistinctness of the patellar tendon. |
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Osgood schlatter lesion
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=tibial tuberosity avulsion
-chronic avulsion injury of the inferior attachment of the patellar tendon -most common in active adolescent boys -pain and swelling over the tibial tuberosity -bony fragmentation of the tibial tuberosity ASSOCIATED with soft tissue swelling, thickening and indistinctness of the patellar tendon |
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Child abuse (nonaccidental trauma)
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-a skeletal survey is often obtained
-other tests include a repeat skeletal survey in 2 weeks to look for healing injuries not seen on the initial survey, skeletal scintigraphy, abdominal CT, and MRI brain. -Highly specific: posterior rib fractures near the costovertebral joints -also metaphyseal corner fracture: usually due to forceful pulling of an extremity. -scapula # -spinous process # -sternal # -spiral long bone fractures in nonambulatory children are also highly suspicious -multiple fractures of various ages and various body parts are highly suspicious Extraskeletal findings: -chronic subdural hematoma -cerebral edema (asphyxia) -brain hematoma -lung contusion -duodenal hematoma -solid abdominal organ laceration -pancreatitis Mimics: -osteogenesis imperfecta -Menkes syndrome (both associated with osteopenia and excessive wormian bones) |
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Periosteal reaction in a newborn DDx
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Physiologic growth
TORCH infections (syphilis, rubella) Prostaglandin therapy Caffey disease (infantile cortical hyperostosis) -Physiologic new bone formation is often seen in the first few months of life. Usually involves rapidly growing long bones such as the femur, tibia, or humerus. Symmetric distribution, benign appearance of periosteal reaction, and appropriate age of the child support the dx. Neuroblastoma metastases Abuse |
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TORCH infections
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Congenital rubella syndrome:
-rubella is the most common transplacental viral infection. Includes eye abnormalities, deafness, hepatosplenomegaly, aortic and pulmonic stenosis, and IUGR. Bony changes in as many as 50% of cases. -Bone findings include irregular fraying of the metaphyses of long bones and generalized lucency of the metaphyses. Celery stalk appearance (alternating light and dark bands tranversely). Syphilis: -transplacental infection -hepatosplenomegaly, rash, rhinorrhea, anemia, and ascites. -bone findings in 95% -nonspecific metaphyseal lucent bands and periosteal reaction involving multiple long bones. -Wimberger corner sign: most specific sign of Syphilis and is destruction of the medial portion of the proximal metaphysis of the tibia, resulting in an area of irregular lucency. -bone manifestations of syphilis are more commonly encountered than other torch infections. |
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Caffey disease (infantile cortical hyperostosis)
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-idiopathic syndrome that consists of periosteal reaction, irritability, fever, and soft tissue swelling over the area of periosteal reaction.
-first few months of life -Bones most commonly involved include the mandible, clavicle, ribs, humerus, ulna, femur, scapula, and radius. -Periosteal new bone, sclerosis, and adjacent soft tissue swelling. -self limited and is now pretty rare -increased uptake on bone scan |
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Lucent permeative lesions in a child DDx
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Under 5 yrs:
Osteomyelitis LCH Neuroblastoma metastases Over 5 yrs: Ewing sarcoma Lymphoma/leukemia Osteomyelitis LCH -Ewing sarcoma and lymphoma are exceedingly rare in children younger than 5. |
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Osteomyelitis
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-primarily a disease of infants and young children.
-ESR elevated in majority of cases -most cases are hematogenous in origin -many have a recent hx of rti or otitis media -staph aureus is the most common cause -children: osteomyelitis tends to occur in the metaphyses or metaphyseal equivalents (due to the rich and slow moving blood supply to these regions). Most common sites are the femur, tibia, and humerus. Other cases occur in the metaphyseal equivalents of flat bones, most typically involving the bony pelvis. -first rad findings are deep soft tissue swelling. Bone changes may not be seen until 10 days after the onset of symptoms. Initial bone changes include poorly defined lucency involving a metaphyseal area. Progressive bony destruction. Periosteal new bone begins at 10 days. -can appear sclerotic when chronic -bone scan: increased activity on all 3 phases. -MR: increased T2 signal in metaphysis. Gd admin may show areas of nonenhancement suspicious for necrosis or abscess formation. IDs drainable fluid for surgical planning. |
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LCH
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-idiopathic disorder. Twice more common in males. More common in whites.
-Letterer-Siwe disease: acute disseminated disease that occurs in children under 1 yr of age. Acute onset of hepatosplenomegaly, rash, lymphadenopathy, marrow failure, and pulmonary involvement. May not have skeletal involvement. Most children die within 1-2 yrs. -Hand-Schuller-Christian disease: the chronic form of systemic LCH. Most have skeletal involvement. Other manifestations include hepatosplenomegaly, diabetes insipidus, exopthalmos, dermatitis, and growth retardation. Usually present between 3-6 yrs. High morbidity rate. -EG: isolated to bone or lung. 70% of cases of LCH. Most cases have a single site of bony involvement. -radiographic appearance of skeletal LCH is very variable. May be lucent or sclerotic, permeative or geographic, sclerotic or poorly defined border. -Most common sites are the skull, ribs, femur, pelvis, spine, and mandible. -Skull lesions may have a beveled edge, related to uneven involvement of inner and outer tables. -Rib lesions may be multiple and have an expanded appearance. -Spine: classic vertebra plana -mandible: floating tooth -if see a lesion suspicious for LCH, should do a skeletal survey to look for other bony involvement, a chest xray to exclude pulmonary involvement, and an mri or ct to characterize and evaluate the anatomic extent of disease. |
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Ewing Sarcoma
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-second most common bone primary after osteosarcoma
-small round blue cell tumor -most common in 2nd decade -exceedingly rare under 5 yrs of age -Most common sites: femur, pelvis, tibia, humerus, and ribs. Two thirds of cases involve the femur or pelvis! -most lesions are in the metaphysis, but diaphyseal involvement is more common than it is in other bone malignancies. -most have an aggressive appearance: lucent, poorly defined borders, and a permeative appearance. Aggressive periosteal rxn is common. But, can appear predominantly sclerotic in 15%. -MR: often a destructive mass with a soft tissue component. |
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Metastatic disease
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-in children, most cases of mets are from small round blue cell tumors.
-most common neoplasms to metastasize to the bone are neuroblastoma and leukemia/lymphoma. -In any child under 3 yo with a neoplastic bony lesions, metastatic neuroblastoma should be considered, and is MUCH more likely than a primary bone neoplasm!!!!! -Leukemia and lymphoma can deposit in the metaphyses and cause bony destruction.....lucent metaphyseal bands! Referred to as leukemic lines. -primary bone lymphoma is rare in children. |
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Focal sclerotic lesions in children DDx
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Osteoid osteoma
Chronic osteomyelitis Stress fracture Osteosarcoma |
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Osteoid osteoma
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-Most common in second decade
-present with pain, worse at night, relieved by nsaids -more common in boys -Most commonly, occur in the cortex of the metadiaphyses or diaphyses of the long bones of the lower extremities. -lucent cortical nidus surrounded by an area of reactive sclerosis. Nidus usually under 1.5 cm in diameter. Usually, a central dot within a lucent area, surrounded by a sclerotic density. -double density on bone scan |
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Stress fracture
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-(fatigue fracture)
-Most common sites, in decreasing order in children are: tibia fibula matatarsals calcaneus -transverse or oblique band of sclerosis or a lucent line surrounded by sclerosis or periosteal new bone formation -periosteal new bone formation may be the only finding -tibia: proximal posterior cortex most common, although anterior cortex can also be involved -calcaneus: vertical sclerotic band paralleling the posterior cortex -bone scan: focal increased uptake days to weeks prior to the development of radiographic findings -CT will show the linear nature of the lesion -MR: low signal linear structures with surrounding high T2 signal edema |
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Osteosarcoma
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-most common primary bone malignancy of childhood
-10-15 yrs most common, males greater than females -predisposing conditions: hereditary retinoblastoma and previous radiation therapy -most arise in the medullary cavity -most common site is metaphyses of long bones -More than 60% arise in the region of the knee (distal femur or proximal tibia) -cloudlike density -usually large soft tissue mass present -In poorly differentiated, very aggressive lesions, tumor bone may not be present and the lesion may appear as a nonspecific, aggressive lucent lesion. -MRI: extent and surgical planning. MRI not accurate in distinguishing peritumoral marrow edema from tumor involved marrow. All abnormal signal in the marrow is generally considered to be involved by tumor for the sake of surgical planning. MRI is accurate in depicting the relationship between the soft tissue mass and adjacent nerves and vascular structures. -MR: must image the entire length of the bone because can occasionally have skip lesions! -Sx and chemo is tx -limb salvage procedures in 80% of pts -Often, a course of chemo is given and then the pt is re imaged prior to sx -Most common type of mets is pulmonary (lung nodules) -skeletal metastatic disease occurs in as many as 15% and is evaluated by scintigraphy. |
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Multifocal bone lesions in children
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-Osteomyelitis
-LCH -Mets Hereditary syndromes: -Osteochondromatosis: arise from the metaphysis. Tendency to point AWAY from joints. Most common in bones surrounding the knee. Osteochondromatosis: can lead to limb shortening, leg length discrepancy, bowing and deformity, compression of adjacent nerves and vessels, and malignant degen into chondrosarcoma (5%). The more proximal lesions have a greater propensity for malignant degeneration. Enchondromatosis (Ollier disease).CAN all be located on one side of the body. Solitary enchondromas tend to occur in the hands and feet, whereas with osteochondromatosis tends to be in the metaphyses of long bones. Plus phleboliths: Maffucci syndrome. Higher incidence of malignant degen than Ollier, and are also at increased risk for malignant neoplasms of the abdomen and CNS. Enchondromas can be flame shaped. -McCune Albright syndrome: polyostotic fibrous dysplasia, skin pigmentation abnormalities, precocious puberty in girls. Polyostotic fibrous dysplasia most commonly involves the facial bones, pelvis, spine, and proximal humeri. Lesions tend to be unilateral. Many present with pathologic fracture by 10 yrs old. No predisposition to malignancy! Purely lytic or sclerotic, and can be expansile or nonexpansile. Classic description is ground glass. Periosteal reaction should be present ONLY if there is a fracture! -Neurofibromatosis |
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Constitutional disorders of bone
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-developmental abnormalities of bone resulting in diffuse skeletal abnormality
-Skeletal dysplasias -Mucopolysaccharidoses -Osteogenesis imperfecta -Osteopetrosis |
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Skeletal dysplasias
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-Evaluation requires images of the skull, spine, thorax, pelvis, and extremities.
-Extremity shortening: 1. Rhizomelic: proximal shortening (humerus, femur). Seen in achondroplasia and thanatophoric dwarfism. 2. Mesomelic: middle shortening (radius/ulta, tib/fib). Most of the mesomelic dysplasias are quite rare. 3. Acromelic: distal shortening. Seen with asphyxiating thoracic dystrophy (Jeune syndrome), and chondroectodermal dysplasia (Ellis-van Creveld syndrome). Other helpful factors: -skull enlargement -short ribs -short spine -abnormal vertebral bodies -abnormal pelvic configuration (abnormal iliac wings or acetabulum). Iliac wings may be abnormally tall or short or have a squared appearance. The acetabular roof may be horizontal (decreased acetabular angle). Trident acetabulum: acetabulum has 3 inferior pointing spikes resembling an upside down trident (buzz word for Jeune syndrome, but can also be seen with Ellis-van Creveld syndrome and thanatophoric dysplasia. -For a summary, see Donnelly p.187 |
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Achondroplasia
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-Most common short limbed dwarfism.
-Autosomal dominant -heterozygous form demonstrates clinical manifestations, and the homozygous form is lethal. -rhizomelic limb shortening -craniofacial disproportion -enlarged skull -small skull base,including small foramen magnum and jugular foramen which may result in brain stem compression -vertebral bodies are short and decreased in AP diameter -disc spaces are too tall -a decrease in the interpediculate distance, being more narrow in the more inferior lumbar spine (opposite of normal). And, short pedicles. -thus, prone to spinal stenosis. -vertebral bodies slightly flattened, can be bullet shaped. Can have scalloping of posterior vertebral bodies. -thoracolumbar kyphosis -lumbar hyperlordosis -shortened bones may show metaphyseal flaring (cone or chevron shaped) -in infants, there is commonly space between the middle fingers, resulting in a trident appearance of the hand. i.e. two pairs of fingers and the thumb. -iliac bones are short (i.e. in craniocaudal length), acetabular roof is horizontal making the iliac bones look like tombstones. -fibulas can be too long for tibias |
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Mucopolysaccharidoses
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-hereditary, defects in lysosomal enzymes.
-include Hunter, Hurler, and Morquio syndromes. -Skeletal findings are similar and have been referred to as dyostosis multilplex. -vertebral bodies are oval in shape and often have a beak in the anterior cortex. -Beak in Midportion of Morquio -Beak in inferior portion in Hurlur -Beaking is most prominent in the lumbar vertebral bodies. -Can be focal kyphosis (gibbus deformity) -Clavicles and ribs are commonly thickened. -Ribs are narrower posteromedially, giving them a "canoe paddle" appearance -Appearance of pelvis is opposite to achondroplasia: iliac wings are tall and flared, acetabuli are shallow. -Femoral heads are dysplastic, and femoral necks are gracile and demonstrate coxa valga -Hands: characteristic appearance that includes proximal tapering of the metatarsal bones |
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Osteogenesis Imperfecta
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-heterogeneous group of genetic disorders
-result in the formation of abnormal type 1 collagen -In all types, there is osteopenia and a propensity for fractures -Often evidence of multiple fractures of different ages -fatal recessive congenital form -dominant tarda form -Classic congenital cases: thick tubular bones from healing of multiple fractures, resulting in short lim dwarfism -tarda form: thin gracile bones with undertubulation. -OI tarda often treated with bisphosphonate therapy: can result in a striking pattern of alternating sclerotic and lucent bands within the metaphyses of fast growing bones. -Multiple wormian bones (small ossicles along the cranial sutures), blue sclera, and thin skin are also commonly seen. -(Normal number of wormian bones: up to 12) |
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Osteopetrosis
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-osteoclases are defective in resorbing and remodeling bone
-as a result, bone is laid down and not resorbed -dense bony sclerosis, often a bone in bone appearance -skull base is thickened and encroachment upon the cranial nerves is a common complication -total body calcium increased, but serum calcium is often paradoxically low -radiographic findings of superimposed rickets are not uncommon -lack of normal marrow space results in pancytopenia, which often leads to death |
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Developmental dysplasia of the hip
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-abnormal development of acetabulum
-ligamentous laxity -much more common in females (9:1 ratio), whites, breech -one third are bilateral -Barlow (dislocation) and Ortolani (relocation) -can lead to chronic abnormalities if not corrected early -there is physiologic ligamentous laxity within 2 weeks of birth.....should wait 2 weeks before US -static view is with probe coronal to the hip -stress maneuvers (Barlow) are performed while evaluating the hip in the axial plane -On the static coronal view, the anatomy simulates that seen on a frontal radiograph of the pelvis: iliac bone is an echogenic line, and this line should bisect a nondislocated femoral head. A dislocated femoral head will be positioned posterior and lateral to the iliac line. The angle created between lines drawn along the straight part of the iliac bone and the acetabular roof is the alpha angle. Normal is greater than 60 degrees (55 degrees in newborns). -DDH: acetabulum is shallow, resulting in a decreased alpha angle, which correlates with an increased acetabular angle on radiographs. -A decreased alpha angle may be followed on repeat static ultrasound during therapy to evaluate for morphologic improvement -radiographs are useful after the femoral heads begin to ossify (US of little value here) -Lines to evaluate on radiographs include the Hilgenreiner line (line drawn through the bilateral triradiate cartilages), the Perkins line (perpendicular to the Hilgenreiner line and traverses the superolateral corner of the acetabulum), and the acetabular angles (normally, less than 30 degrees at birth and decreases to 22 degrees at 1 year of age)(with DDH, acetabular angles are abnormally increased) -Another cause of abnormally increased acetabular angles: neuromuscular disorders. -Abnormally decreased acetabular angles: during the first year of life in T21 and in multiple dysplasias including achondroplasia -Perkin line: when femoral head ossified and visible, it should lie medial to perkins line. When the head is not ossified, the perkins line should bisect the middle third of the metaphysis. If the metaphysis is lateral to this position, it is subluxed or dislocated. -Shenton arc: smooth arch connecting the medial cortex of the proximal metaphysis of the femur and the inferior edge of the superior pubic ramus. In DDH and dislocation, the arc is discontinuous |
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Chronic hip subluxation
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-neuromuscular disorders such as cerebral palsy
-development of progressive hip subluxation/dislocation may occur -radiographs are used to evaluate how much the bony acetabulum covers the femoral head (% coverage), the degree of coxa valga, and the presence of complete dislocation |
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Proximal focal femoral deficiency
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-congenital disorder consisting of a range of hypoplasias to the absence of the proximal portions of the femur
-most severe form: acetabulum, femoral head, and proximal femur are absent -varus deformity is commonly associated -in DDH on the other hand, the femur is of normal length! -PFFD can be associated with ipsilateral fibular hemimelia and deformity of the foot |
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Septic Arthritis
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-most urgent dx to exlude in a patient with a painful joint
-in children, septic arthritis is thought to occur most commonly as a result of extension of infection from the adjacent metaphysis. -in younger children, usually due to bacterial sepsis, most common organism is staph aureus and group A strep -most are monoarticular, involve large joints (hip followed by knee) -pain, limp, failure to weight bear -primary radiographic finding is asymmetric widening of the hip joint space by more than 2 mm on a nonrotated film. -BUT, this isn't sensitive for a joint effusion -displacement or obliteration of the fat pads surrounding the hip may be noted including the obturator internus, gluteus muscle, and iliopsoas fat pads (also insensitive) -normal radiographs do not exclude -joint effusion evaluated by US -the absence of fluid does not exclude septic arthritis -when fluid is present, US can tap joint -Causes of effusion other than septic arthritis: toxic synovitis, noninfectious arthritis, and Legg Calfe Perthes disease |
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DDx hip pain (varies by age)
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Septic arthritis (any age)
Toxic synovitis (under 10 yrs) Osteomyelitis (under 5 yrs) LCH (any age, but pelvic bone involvement usually under 5 yrs) Legg-Calve-Perthes disease (5-8 yrs) SCFE (12-15 yrs) JRA (1-3 yrs) Ewing sarcoma (second decade) Osteoid osteoma (second decade) |
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Toxic synovitis
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-pain/limp, joint effusion, and no organisms in joint aspiration
-symptoms subside with rest -it occurs in children less than 10 yrs of age -diagnosis of exclusion -thought to be secondary to viral infection |
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Legg-Calve-Perthes disease
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-idiopathic avascular necrosis of the proximal femoral epiphysis.
-more commonly in boys (4:1) -more common in whites -5-8 yrs old -pain in the groin, hip, or ipsilateral knee -bilateral in 13% -often associated with skeletal immaturity (decreased bone age) -early findings: asymmetric, small ossified femoral epiphysis, widening of the joint space as a result of either a joint effusion or synovial hypertrophy, and a subchondral linear lucency (crescent sign...seen best on frog-leg lateral views) -MR: high T2 signal marrow edema, low T1 (loss of the normal fatty signal in the epiphysis!), asymmetric decreased enhancement with gadolinium -bone scan (lack of uptake) -Later changes: fragmentation, areas of sclerosis and lucency, and loss of height (collapse). -Chronic LCP can result in a broad, overgrown femoral head (coxa magna), a short femoral neck, and physeal arrest -can get metaphyseal lucencies as well -may need surgical reconstruction of the acetabulum to provide increased covarage of the femoral head |
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SCFE
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-idiopathic Salter 1 fracture through proximal physis of the femur
-M:F 2:1 -more common in african americans and in obese -certain groups, i.e. with renal osteodystrophy, are predisposed -Bilateral in 1/3rd!!!!!!!!!!!!!! -but, both hips don't usually present at the same time -12-15 yrs -femoral head slips posterior and to a lesser extent medial -findings are more prominent on the frog-leg lateral view than the frontal view -frog-leg lateral view: a line drawn tangential to the lateral cortex of the metaphysis should bisect a portion of the ossified epiphysis. -if the epiphysis is medial to this line, it has slipped -findings on frontal view (can be very subtle): asymmetric widening of the physis and indistinctness of the metaphyseal border of the physis -treated with pin fixation to prevent further slippage, but the epiphysis is NOT moved back to its normal position!!! -potential complications: AVN and chondrolysis |
