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214 Cards in this Set
- Front
- Back
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An avulsion of the ASIS apophysis is caused the pull of what muscle? |
Sartorius |
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An avulsion of the AIIS apophysis is caused by the pull of what muscle? |
Rectus Femoris
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What is the most common type of hip dislocation?
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posterior, secondary to a mvc. concerning regarding the sciatic nerve
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What is a Judet view?
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dedicated view to r/o an acetabular fx
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What is Legg Calve Perthes Disease? When does it occur?
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avascular necrosis of the femoral head. 4-8 yoa.
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If you are concerned re a SCFE which view is it necessary to get? |
Groin Lateral or a Billing projection
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What does HADD stand for?
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Hydroxyapatite deposition disease. a major cause of chrnic hip pain
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What is a Jefferson fracture?
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burst fx of C1
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An insufficiency fracture of the sacrum is found in what 2 types of patients?
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osteoporosis and pts who have had prior radiation to the pelvis
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What study is best to visualize occult fractures?
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MRI because it allows the identification of marrow fx lines
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Whatt is Myositis Ossificans?
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formation of peripheral calcification in a previously injured muscle
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What is a Trough SIgn?
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a lucency in the glenohumeral junctionwhich indicates impaction from a posterior dislocation
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What is the difference in calcification between myositis ossificans and parosteal sarcoma? |
Myositis Ossificans will have peripheral ossification/calcification.
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What is a free or sequestered fragment?
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when disk material migrates from the parent disc
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What is a Tarlov Cyst?
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an enlarged nerve root sheath, a nl variant. It may also be called a Perineural Cyst
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What is a conjoined root?
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congenital anomaly of 2 nerve roots exiting the thecal sac together instead of separately. a conjoined root will have a lower density than the thecal sac
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What is a lateral disc and why is it clinically important?
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It is a disc protrusion that occurs lateral to the neuroforamen. it can irritate a nerve root that has already exited the foramen and will mimic a disk protrusion at a higher level. |
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What are the 2 tyes of Spinal Stenosis?
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Congenital and acquired
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Who gets Congenital Spinal Stenosis?
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Achondroplastic Dwarfs, Morquio's Disease
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What are the 3 types of Spinal Stenosis?
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central canal, neuroforaminal, lateral recess
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What are the 2 most useful CT findings to diagnose spinal stenosis?
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obliteration of the epidural fat and flattening of the thecal sac
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Name some aquired causes of spinal stenosis?
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hypertrophy of ligamentum flavum, pagets, ossification of the posterior longitudinal ligament,diffuse idiopathic skeletal hyperostosis
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What are the MC cause of Neuroforaminal Stenosis?
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DJD, Osteophytes
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What is Spondylolisthesis?
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anterior displacenebt of a cephalad vertebral body with respect to a caudad vertebral body
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What is the grading for Spondylolisthesis?
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I-25%, II 25-50%, III 50-75%, IV 75-100%
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What is Spondylosis?
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degenerative disease at the facet joints
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What is Spondylolysis?
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Pars Interarticularis defect
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What is Osteitis Condensans Ilii?
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triangular-shaped aareas of slerosis noted in the iliem of the SI joint
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What is Osteitis Pubis?
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historically infection of the pubic symphysis after bladder surgery
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What is the typical bony finding in Multiple Myeloma?
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"swiss cheese"
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What is the differential diagnosis of a sequestrum on CT?
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Eosinophilic Granuloma, Osteomyelitis, Desmoid, and Osteoid Osteoma
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What is the significance of a sequestrum?
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Antibiotics do not suffice because the sequestrum doesn't have a blood supply and antibiotics can't reach it
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What is a helpful sign of bony metastisis?
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permeative appearance which suggests a marrow based process
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What are Scmorl's Nodes?
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herniation of disc material through the end plate of a vertebral body
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What are Tarlov Cysts?
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nerve sheath dilitations whose densities are similar to csf
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What are the CT findings in Paget's Disease?
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cortical thickening,bone overgrowth 2 findings not seen in Multiple Myeloma
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What is Fibrous Dysplasia?
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a congenital disorder of bone growth leading o fibrous tissue, chondral tissue, and cysts within bones. usually an incidental finding. never has periostitis, malignant transformation, or is painful.
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How do you make the diagnosis of patella alta?
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using the Insall and Salvati method. Patella tendon lenth/patella lenght if >1.2, if <0.8 Patella Baja is present
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What is the Fabella?
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sesamoid bone, located in the lateral head of the Gastrocnemius muscle
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What are the attatchments of the ACL?
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the lateral femoral condyle withn the intercondylar notch and the anterior intercondylar eminence of the tibia
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What are the attachments of the PCL?
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the medial femoral condyle within the intercondylar notch and the posterior intercondylar eminence of the tibia
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Where is the peroneal nerve located?
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adjacent to the head of the fibula
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What is a housemaid's knee?
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Prepatellar effusion
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Tibial plateau fx usually result from what kind of blow to the knee?
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Lateral, valgus blow
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What is the most common side for tibial plateau fx?
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lateral
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What is the %age popliteal artery injury in a knee dislocation?
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30%
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What is the Sleeve fracture of the patella?
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occurs in children, a portion of the lower cartilage is avulsed from the lower pole
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What is Blount's Disease?
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Infantile Tibia Vara, breaking or fragmentation of the medial tibia metaphysis with medial angukation of the leg
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What is a Valgus Deformity?
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when the distal segment of the joint is displced laterally
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What is Osgood Schlatter's Disease?
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tractional injury at the tibial tubercle at the patellar tendon insertion site. occurs in kids who recently had a growth spurt
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What is Pellegrini-Stieda Calcification?
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it is a dystrophic response to a damaged medial collateral ligament, near the medial condyle of the tibia
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Chondrocalcinosis
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CPPD, Calcium pyrophosphate dihydrate depostion seen at the periphery at the medial and lateral joint spaces
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What is Osteochondritis Dissecans?
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separation of the rticular surface of the medial femoral condyle
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What is a Cortical Desmoid?
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nl pediatric variant lucency involvong the pos-medial aspect of the distal femoral metaphysis
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multiple myeloma?
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most common primary malignant neoplasm of bone
50-70y; M:F 2:1 symptoms: vague bone pain of progressive severity, fever, anemic sxs complications: pathologic fractures solitary plasmacytoma: solitary osseous focus of MM (uncommon) x-ray findings: loss of bone density - from diffuse marrow involvement "punched out" lesions - esp. skull, long bones diffuse bone destruction - esp. pelvis, sacrum invasion of soft tissues - often paraspinal, extrapleural mass osteosclerosis - very rare metastatic calcifications - particularly kidneys, occ. lungs NB: does not involve pedicles of spine |
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Maisonneuve fracture
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components:
fracture of the proximal third of the fibula rupture of the distal tibiofibular syndesmosis associated with: fracture of the tibia rupture of the deltoid ligament caused by an ABDUCTION and EXTERNAL rotation force applied to the ankle which forces the talus laterally against the fibula |
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Schmorl node
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chondrification defects where periosteal vessels penetrate cartilage plates of disc
Xray: concave defects at upper and lower vertebral endplates with sharp margins produced by herniation of disc material MRI: similar signal intensity as disc low signal intensity of rim associated with narrow disc space DDx: "SHOOT" Scheuermann disease hyperparathyroidism osteoporosis osteomalacia trauma |
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neuropathic (Charcot) joint
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M > F
age > 40 yrs 6 D's destruction increased density dislocation debris distension disorganization etiologies diabetic neuropathy syphilis (tabes dorsalis) syrinx meningomyelocele / spina bifida nerve injury: spinal cord or peripheral nerves congenital insensitivity to pain leprosy Charcot-Marie-Tooth syndrome |
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Adamantinoma
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resembles fibrous dysplasia
occurs primarily in the tibia and jaw malignant |
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McCune-ALbright Syndrome
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polyostotic fibrous dysplasia
cafe-au-lait precocious puberty |
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Cherubism
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multiple lesions of fibrous dysplasia in the jaw
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Enchondroma
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lytic lesion in phalanges
usually containscalcified chondroid matrix, but not in the fingers not usually painful if painful think chondrosarcoma pathologic fractures |
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Bone Infarct
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well defined densely sclerotic serpiginous borders
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Ollier Disease
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multiple enchondromas
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Maffucci Syndrome
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multiple enchondromas associated with soft tissue hemangiomas
increased incidence of malignant degeneration |
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Eosinophilic Granuloma
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form of histiocytosis X
exclusively in pts < 30 yoa mention in any bony lesion if pt is < 30 yoa |
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Differential for a lesion with a bony sequestrum
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EG
Osteomyelitis Lymphoma Fibrosarcoma Osteoid Osteoma |
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Giant Cell Tumor
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unable to tell benign or malignant on xray
Occurs only in pts with closed epiphyses Must be epiphyseal and abut the articular surface eccentric well defined non-sclerotic margin |
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4 Giant Cell Tumor Rules
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Occurs only in pts with closed epiphyses
Must be epiphyseal and abut the articular surface eccentric well defined non-sclerotic margin Rules do not apply to flat bones. |
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NOF (non-ossifying fibroma
Fibrous Cortical Defect (< 2cm) |
well defined lytic minimally expansile assymptomatic,< 30 yoa, cortically based.
don't touch lesion |
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Osteoblastoma
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mention when ABC esp in the post elements of the spine
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Metastatic Disease
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consider for any lytic lesion in anybody > 40 yoa.
a metastatic lesion can appear benign |
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Plasmacytoma
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bubbly lytic lesions of multiple myeloma
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In general lytic expansile lesions tend to come from?
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Thyroid
Renal |
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The only metastatic lesion that is always lytic?
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RCC
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Aneurysmal bone cyst
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<30 yoa
painful often occur in posterior spine |
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Solitary Bone Cysts
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Central!
Fallen fragment sign pathognomonic prox long bones < 30 yoa no periostitis |
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Hyperparathyroid (Brown tumors)
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subperiosteal bone resorption mc in radial aspect of middle phalanges
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Chondroblastoma
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<30 yoa
epiphyseal |
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Differential Dx of an epiphyseal lytic lesion in a pt < 30 yoa
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Infection
Chondroblastoma Giant cell tumor |
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Subchondral Cyst or Geode occurs in what 4 diseases
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DJD
RA Pseudogout AVN |
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Chondromyxoid Fibroma
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mention with NOF
no calcified matrix rare |
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Lesions in pts younger than 30
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EG
ABC NOF Chondroblastoma Solitary bone cyst |
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Lesions without pain or periostitis
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FD
Enchondroma NOF Solitary bone cyst |
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Bony lesion to always mention?
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<30 yoa
infection, EG >40 yoa infection, mets, mm |
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Epiphyseal DDX
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infection, Gaint cell tumor, Chondroblastoma, Geode
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The only lesion that must have a calcified matrix?
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Enchondroma
(except in the phalanges) |
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4 indicators of a bony lesion that determine malignancy?
What is the most useful indicator? |
cortical destruction
periostitis orientation/axis (not very helpful) zone of transition (most useful) |
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2 benign lesions that may look malignant
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EG
Infection |
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Benign periostitis has what type of characteristics
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thick
dense wavy |
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Malignant periostitis has what type of characteristics
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lamellated
amorphous sunburst |
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Name a lesion that grows in the long axis of the bone, but is very malignant
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Ewing Sarcoma
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What is a permeative lesion
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a lesion consisting of many small holes
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2 childhood primary malignant bone tumors
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Ewings Sarcoma
Osteosarcoma |
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Malignant bone tumors after 40 yoa
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Chondrosarcoma
Mets Myeloma |
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Where do paraosteal osteosarcomas originate from
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periosteum of the bone and grows outside. It often wraps around the diaphysis without breaking the cortex. if it breaks the cortexit is considered agressive and has a worse prognosis
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What benign lesions can mimic a paraosteal osteosarcom?
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Cortical Desmoid Tumor
Myositis Ossificans |
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What is a cortical Desmoid Tumor
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An avulsion injury that is entirely benign, but looks agressive
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What is the differential for a bony permeative lesion in a child
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Ewings
Infection EG |
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Chondrosarcoma rarely occurs in children, but it can occur when what type of tumor degenerates
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Osteochondroma
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What percent of Giant Cell tumors metastasize? Where do they metastasize to?
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15%
Lung |
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What 3 bony tumors can have a bony sequestrum
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Fibrosarcoma
Malignant Fibrous Histiocytoma Desmoid tumor |
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What is the only malignant bone tumor that can involve a large amount of bone eventhough the pt is assymptomatic
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Reticulum Cell Sarcoma
(primary Bone Lymphoma) |
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What is one of the only bony lesions that is not hot on a bone scan
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Myeloma
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What are the 2 MC soft tissue tumors
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Liposarcoma
Malignant Fibrous Histiocytoma |
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Spondylolysis
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a break or defect in the pars interarticularis of the lamina
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Kummel Disease
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occurs 1 to 2 weeks after initial trauma. a wedge compression fx further collapse
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What disease always requires increased imaging in trauma?
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Ankylosing spondylitis
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Failure to treat a lunate dislocation will effect which nerve?
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Median
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peri-lunate dislocation
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* lunate remains aligned with radius
* capitate dislocates (usually posteriorly) * more common than lunate dislocation (radial-lunate ligaments stronger than lunate-capitate ligaments) * associated with scaphoid fractures (75%) = "transscaphoid perilunate dislocation" |
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lunate dislocation
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* lunate dislocates posteriorly
* other carpal bones remain in alignment less common than perilunate dislocation |
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Kienbock Malacia
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* lunate AVN
* associated with ulnar minus variance |
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A small chip of bone off the dorsum of the wrist is which bone
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Triquetrum
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Colles FX
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* radial fracture in distal 2 cm
* +/- ulnar styloid fracture * dorsal displacement of distal fragment * "silver-fork" deformity * most common fracture in this region * mechanism: fall on an outstretched hand * complication: post-traumatic arthritis |
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Smith FX
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fx distal radius ("reverse Colles")
volar angulation of distal fragment |
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Barton FX
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intra-articular fracture of distal radius
* dorsal displacement of separated fragment * due to fall on outstretched hand |
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Chaffeur's FX
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radial styloid fracture due to direct blow
* (so named because of trauma from hand-cranked starters) |
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Monteggia FX
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angulated fracture at the junction of the proximal and middle third of ulna accompained by ANTERIOR dislocation of the radial head
etiology: * transmission of force thorugh the hand and forearm with the elbow partially flexed * interosseous ligament "drags" the radius with the distal two-thirds of the ulna # MUGR mnemonic * Monteggia with ulna (proximal) * Galeazzi with radius (distal) |
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Galeazzi FX
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radial fx
dislocated distal ulna * mnemonic: "MUGR" (Monteggia ulna, Galeazzi radius) * Monteggia More common |
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What are the 3 hallmarks of DJD?
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Sclerosis
Joint space narrowing Osteophytosis |
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Bohler Angle
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< 20 degrees indicates a calcaneal fx
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Ochronosis
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aka: alkaptonuria
* autosomal recessive * excessive homogentisic acid o no homogentisic acid oxidase o part of phenylalanine / tyrosine pathway * alkaptonuria: brown/black urine * ochronosis: brown/black pigmentation of skin, mucous membranes * pigment deposition in articular cartilage of joints o ==> chronic arthritis (usually evident in 4th decade) * narrowed, calcified intervertebral disks * renal calculi * nephrocalcinosis |
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CPPD
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manifestations can occur singly or in any combination
* pseudogout o acute crystal-induced synovitis with clinical symptoms analogous to gout * arthropathy o beaklike osteophytes of 2nd, 3rd metacarpal heads o subchondral cysts (esp. carpal bones) o unusual distribution of disease (radiocarpal/ulnar joint, patellofemoral joint) o SLAC - scapholunate advanced collapse * chondrocalcinosis o triangular fibrocartilage o symphysis pubis o menisci of knee o annulus fibrosus of intervertebral disk |
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Name 3 diseases with high association with CPPD
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Hyperparathyroidism
Hemachromatosis Gout |
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T or F, No malignant tumors arise from joints
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True
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PVNS
Pigmented Villonodular Synovitis |
* monoarthritis
* young adults * benign neoplasm affecting extremity joints * subchondral erosions on BOTH sides of joint (!) * hemosiderin deposited in synovium (with characteristic low signal on MR) * articular cartilage preserved (despite extensive marginal erosions; similar to gout) * NO calcification, but soft tissue may appear dense on X-ray/CT DDx: * TB (associated atrophy of muscle + bone) * rheumatoid arthritis (symmetrical) * synovial sarcoma (+/- calcified; outside joint) * synovial osteochondromatosis |
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RSD
Sudeck Atrophy |
Sudeck dystrophy, causalgia, shoulder-hand syndrome, post-traumatic osteoporosis
* pain, tenderness, soft tissue swelling out of proportion to injury * vasomotor instability (Raynaud, vasoconstriction/-dilation) * end stage (6-12 months): contractures, atrophy (skin and soft tissues) * location: hands and feet distal to injury etiology * injury (fracture, frost bite; may be trivial) * immobilization * infection * myocardial infarction findings * periarticular soft tissue swelling * patchy dimineralization * increased uptake (periarticular) on bone scan * perfusion and blood pool phases not sensitive |
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Which fat pad gets displaced with a hip joint effusion
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Obturator Internus
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Causes of AVN?
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Etiology ("PLASTIC RAGS"):
P pancreatitis L lupus A alcohol S steroids T trauma I idiopathic, infection C caisson disease, collagen vascular disease R radiation, rheumatoid arthritis A amyloid G Gaucher disease S sickle cell disease findings: * sclerosis * crescent sign * collapse (e.g., of femoral head) |
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AVN Staging
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Stage CT/xray bone scan
----- ------- --------- I - cold/hot spot II sclerotic focus with osteopenic ring III "crescent sign" (subchondral lucency) IV articular collapse flattening of femoral head sensitivity 86% 78% specificity 79% 75% |
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What is the earliest sign of AVN
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effusion
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Kohler Disease
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osteochondrosis of tarsal navicular
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Osteochondrosis
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degeneration followed by reossification of one or more ossification centers in children
* Legg-Calve-Perthes disease (capital femoral epiphysis) * Kohler disease (tarsal navicular) * Osgood-Schlatter disease (tibial tuberosity) * Scheuermann disease (vertebral ring epiphyses) * Freiberg infraction (metatarsal head) * Sever disease (apophysis of os calcis) * osteochondritis dissecans All osteochondrosis have a low signal on T1 |
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Osteochondritis Dissecans
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subchondral fatigue fracture commonly seen in adolescents
1. capitellum of elbow 2. knee * medial femoral condyle close to fossa intercondylaris * bilateral in 20-30%, rarely lateral 3. talus * mouse = osteochondrotic fragment * mouse bed = sclerosed pit in articular surface |
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MC site for Osteochondritis Dissecans
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Knee (medial epicondyle), Talus(dome)
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Magic angle phenomenon
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# Increased signal intensity may be present on the upward sloping portion of the PCL on short TE images, mimicking a tear. It is present in anatomic components of the ligament oriented 55° to the main static magnetic field, along the long axis of the magnetic bore.
# The phenomenon can be distinguished from a true PCL tear using long TE-weighted imaging sequences. When using proton-density imaging, the artifact may persist if the TE is 20 milliseconds or less. # If the abnormal signal focus persists, a true PCL abnormality is present. Artifacts from MAP disappear when long TE sequences are used |
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Myositis Ossificans
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circumferential calcification with a lucent center
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Cortical desmoid
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a process on the medial supracondylar ridge of the distal femur that is considered by many to be the result of an avulsion of the adductor magnus muscle
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Where do cortical desmoids occur?
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posteromedial epicondyle of the femur
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Discogenic Vertebral Sclerosis
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always adjacent to the endplate, and the associated disk space should be narrow
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cortical defect of the patella
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lytic defect in the upper outer quadrant. normal variant
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pseudocyst of the humerus
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another entity that is often mistaken for a lytic pathologic lesion. an anatomic variant caused by increased
cancellous bone in the region of the greater tuberosity of the humerus, giving this region a more lucent appearance on radiographs (11,12). With hyperemia and disuse caused by rotator cuff problems or any other shoulder disorder, this area of lucency may appear strikingly more lucent and mimic a lytic lesion |
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Os odontoideum
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normal variant of the cervical spine that may, in fact, be posttraumatic . It is an unfused dens that may move anterior to the C2 body with flexion and can mimic a fractured dens . Many of these require surgical fixation; some surgeons fuse every case, believing that they are all unstable
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Nonossifying fibroma (NOF)
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NOF is identical to a fibrous cortical defect, but the term is usually reserved for defects larger than 2 cm. They are, classically, lytic lesions located in the cortex of the metaphysis of a long bone and have a well-defined, often sclerotic, scalloped border with slight cortical expansion . They are found almost exclusively in patients younger than the age of 30 years; hence, the natural history of the lesion is involution. As they involute, they fill in with new bone, giving it a sclerotic appearance (Fig. 46.20) thus, they can have some increased radionuclide activity on bone scans. They are most often mistaken for an area of infection, eosinophilic granuloma, fibrous dysplasia, or aneurysmal bone cyst. They are asymptomatic.
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Bone islands
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mimic sclerotic metastases always asymptomatic
two signs can be found to help distinguish giant bone islands from metastases. First, bone islands usually are oblong, with their long axis in the axis of stress on the bone: for example, in a long bone they align themselves along the axis of the diaphysis. Second, the margins of a bone island, when examined closely, will show bony trabeculae extending from the lesion into the normal bone in a spiculated fashion (15). This is characteristic of a bone island and helpful in differentiating it from a more aggressive process. |
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Unicameral bone cysts
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often prophylactically curettaged and packed so as to prevent fracture with subsequent deformity. When these cysts occur in the calcaneus, however, they should be left alone. They always occur in the anteroinferior portion of the calcaneus
area that does not receive undue stress. In fact, a pseudotumor of the calcaneus is seen in the identical position because of the absence of stress and resulting atrophy of bony trabeculae (Fig. 46.24). These lesions are asymptomatic, only rarely fracture, and should not suffer the same fate as their counterparts in long bones—that is, surgical removal |
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Bone Infarction
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Early in the course of its development, a bone infarct can have a patchy or mixed lytic-sclerotic pattern or even resemble a permeative process
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achondroplasia
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most common type of short limbed dwarfism; caused by defect in enchondral bone formation => shortening of tubular bones with normal shaft caliber
* hereditary: auto-dominant, > 90% sporadic x-ray features: * short extremities and ribs v. trunk length * "ball-in-socket" epiphyses * pelvis: squared iliac wings and narrow sacrosciatic notch ("champagne glass") * hands: fingers widely opposed and equal length ("trident hands") * skull: enlarged vault and mandible, small f. magnum * spine: o narrow AP diameter with concave posterior surface and spinal canal only 1/2 normal depth o decreased lumbar interpediculate distance o hypoplastic ("bullet nose") T-L vertebrae spine typically has narrowing of the interpedicular distances in a caudal direction (Fig. 47.1), the opposite of normal, in which the interpedicular distances get progressively wider as one proceeds down the spine. The long bones are short but have normal width, giving them a thick appearance |
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Common Causes of Avascular Necrosis
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Trauma
Steroids Collagen vascular diseases Alcoholism, aspirin Idiopathic causes |
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Common Radiographic findings of AVN
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patchy sclerosis
articular surface collapse serpiginous borders subchondral lucency |
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periosteal reaction
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in adults:
* hypertrophic osteoarthropathy (HOA) * pachydermoperiostosis * vascular insufficiency * thyroid acropachy * fluorosis in kids: * physiologic periostosis * Caffey disease * JRA * acute leukemia * scurvy * rickets * congenital syphilis * hypervitaminosis A |
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hypertrophic osteoarthropathy
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* pulmonary
* malignancy (bronchogenic Ca, lymphoma, mets) * abscess * COPD / bronchiectasis * pleural * pleural fibroma (highest incidence of HOA, tho' rare itself) * mesothelioma * cardiac * cyanotic congenital heart dz * GI * inflammatory dz (Crohn, UC) * malabsorption (dysentery, lue, cirrhosis) * ** causes symmetrical periosteal reaction |
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melorheostosis
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rare condition of cortical thickening of unknown etiology most commonly seen in the long bones
* 3-59 years * sx: usu. pain of varying severity, occ. limited ROM, contracture * insidious onset and chronic course xray findings: * cortical sclerosis and thickening that may encroach on the medullary canal -- looks like wax flowing down a candle |
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mucopolysaccharidoses
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abnormal elaboration + storage of mucopolysaccharides
* autosomal recessive (except Hunter [type II], X-linked recessive) Features: * "dysostosis multiplex" (wide medial clavicle, flat ribs, etc.) * short stature * hepatosplenomegaly * coarse facies, ocular disease Types: I Hurler / Scheie II Hunter III Sanfilippo IV Morquio VI Maroteaux-Lamy |
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All mucopolysaccharidoses are AR except which one
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Hunter
x-linked |
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Hurler's syndrome
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mucopolysaccharidosis (MPS) type I (aka: gargoylism)
* autosomal recessive deficiency of X-L iduronidase * 1 in 10000 births * prognosis: death in early teens * dwarfism * mental retardation * kyphosis * long bones are short and thick * phalanges of hands: coarse texture, wide shafts, tapered proximal ends (esp. metacarpals) * hepatosplenomegaly * thick everted lips, large tongue, small malformed teeth * J-shaped sella buildup of heparan sulfate |
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Morquio's disease
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mucopolysaccharidosis (MPS) type IV
* autosomal recessive deficiency of N-acetylgalactosamine-6-sulfatase build up of keratin sulfate * normal intelligence * platyspondyly ("universal vertebra plana" = hallmark) * dwarfism, kyphosis, severe disability * anterior beaks of vertebrae/bullet shaped * "wine glass" pelvis |
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what is a characteristic finding in all of the mucopolysaccharidoses on bone films?
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notch at the base of the fifth metacarpal
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osteochondroma (exostosis)
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* age: 10 - 30 yrs
* bony outgrowth * points away from joint * site: metaphysis; long bones o 50% at knee or shoulder * generally benign o calcified cartilagenous cap ==> premalignant o may --> chondrosarcoma * familial type of multiple osteochondromatoses ==> increased risk of malignancy |
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chondrosarcoma
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* M > F, 35 - 50 yrs
* malignant, poor prognosis * tx: removal, RT * sites: metaphysis, center of flat bones o pelvis, ribs, upper femur, shoulder * slow growing * large soft-tissue mass +/- flocculent calcifications * sclerosis * may arise from pre-existing "benign" enchondroma or osteochondroma |
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hereditary exostosis (osteochondromatosis)
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* autosomal dominant
* M > F * multiple exostoses * "snowflake" calcification of mature cartilage cap * may --> chondrosarcoma * short metacarpals (esp. 4th + 5th) |
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Undertubulation
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widened diameter of the bone, often seen in hereditary exostosis
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osteoid osteoma
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* M:F 2:1, 5 - 25 y/o (90%) (50% 10-20)
* pain at night - prostaglandin E2 * pain responds to salicylates * tx: surgical excision of nidus, rare spontaneous regression * location o metadiaphysis and metaphysis of long bones(73%) o spine (14%) o hands and feet (12%) * lucent nidus with thickened cortex on CT and plain film * Perinidal bone marrow edema and soft tissue inflamation on MRI * DDx: o Brodie abscess o Ewing sarcoma o osteosarcoma o sclerosing osteomyelitis |
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Brodie abscess
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subacute osteomyelitis
* distal end of long bones * well-defined, lytic * +/- sclerotic rim * tx: open abscess, curette, pack with bone chips * prognosis: excellent after tx DDx: * osteoid osteoma * EG |
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Ewing sarcoma
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small, round-cell sarcoma of mesenchyme of medullary bone
* age 5 - 14 yrs * most lethal of all 1' bone tumors * any bone o < 20 y/o: long bones o > 20 y/o: flat bones (where there's still red marrow) * purely lytic (62%), purely sclerotic (15%) * periosteal reaction (onion-skin or perpendicular) * similar lesion at different age o < 5 y/o -- neuroblastoma o > 30 y/o -- mets, reticulum cell sarcoma |
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How can u distinguish between an Osteoid Osteoma and Osteomyelitis?
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because the nidus is extremely vascular, it avidly accumulates radiopharmaceutical bone-scanning agents. An osteoid osteoma will have an area of increased uptake corresponding to the area of reactive sclerosis and will additionally demonstrate a second area of increased uptake corresponding to the nidus (Fig. 47.13). This has been termed the double-density sign (4). In contrast, osteomyelitis has a photopenic area corresponding to the plain film lucency that represents an avascular focus of purulent material. The natural history of an osteoid osteoma is presumed to be spontaneous regression, as they are rarely seen in patients over the age of 30
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Osteopathia Striata
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Voorhoeve disease,
2- to 3-mm-thick linear bands of sclerotic bone aligned parallel to the long axis of a bone (Fig. 47.14). affects multiple long bones asymptomatic incidental finding |
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osteopoikilosis
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rare, autosomal dominant bone disorder
* multiple, small, circumscribed round or ovoid areas of increased bone density, widely distributed, caused by condensations of the spongiosa * NO symptoms associated with: * dermatofibrosis lenticularis disseminata * scleroderma * syndactyly * dwarfism * endocrine abnormalities * melorrheostosis * cleft palate mistaken for diffuse osteoblastic disease incidental finding |
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pachydermoperiostosis |
"idiopathic, familial hypertrophic osteoarthropathy"
* boys at puberty * blacks > whites * familial * periosteal reaction o proximal phalanges, distal long bones of legs and forearms o cortical thickening without medullary narrowing * thick skin: extremities + forehead * hyperhidrosis * relatively pain free |
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Transient osteoporosis of the hip can look like?
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AVN
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Chondromalacia patellae
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most commonly occurs in young adults, is a syndrome of crepitus and pain at the anterior knee associated with cartilaginous changes along the undersurface of the patella
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Bado
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Classification system for Monteggia fracture-dislocations.
* Type I - Fracture of the middle or proximal third of the ulna and anterior dislocation of the radial head (65%). * Type II - "reversed" Monteggia injury. Fracture of the middle or proximal third of the ulna and posterior dislocation of the radial head (18%). * Type III - Ulnar fracture distal to the coronoid process with lateral radial head dislocation (16%). * Type IV - Fracture of the proximal or middle third of the ulna with an anterior dislocation of the radial head and fracture of the proximal third of the radius (rare). |
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Hill-Sachs deformity
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indentation or groove on posterolateral aspect of humeral head
* probably d/t compression of humeral head on posterior lip of glenoid * may occur after one episode of shoulder dislocation a/w: Bankart lesion of glenoid |
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Bankart deformity
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* osteochondral fracture of inferior glenoid labrum
* a/w anterior shoulder dislocation see also: Hill-Sachs deformity |
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WHat us Kummell's Disease?
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delayed post traumatic vertebral body collapse which may follow minimal trauma. May be a subtype of AVN.
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Segond Fx
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a/w acl tear
avulsion of the lateral capsular ligament |
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Wimberger’s sign
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localized bony destruction of the medial portion of the proximal tibial metaphysis
a/w congenital syphillis |
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Saber Shin
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Congenital Syphillis
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Malgaigne fracture
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two vertical fractures involving one side of the pelvic ring
* one fracture anterior to the acetabulum o usually through the pubic ramus * one fracture posterior to the acetabulum o usually through the ilium o separation of the SI joint may occur instead usually the result of direct trauma |
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Segond FX
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avulsion fx px lateral tibia at lateral capsular ligament insertion
avulsion px fibula biceps femoris lateral collateral ligament |
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Little Leaguer's elbow
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avulsion fx of MEDIAL epicondyle
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Panner's Disease
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AVN Capitellum
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Complications of MHE
Multiple Hereditary Exostosis |
Fracture
Vascular injury Neurologic compromise Bursa formation Malignant transformation |
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cancers that tend to calcify
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mucinous adenocarcinoma
breast gi sarcoma neuroblastoma |
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what are the overuse syndromes of the patella?
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The overuse syndromes of the patellar tendon include Osgood-Schlatter disease, Sinding-Larsen-Johansson syndrome, and Jumper’s knee.
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Defint the 3 overuse syndromes of the patella
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Osgood-Schlatter disease, which involves the tibial tubercle, and Sinding-Larsen-Johansson syndrome, which involves the inferior pole of the patella. Jumper’s knee is a chronic tendinitis that affects the patellar tendon at its proximal insertion.
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associates of patella alta include?
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Subluxation
Quadriceps tendon atrophy Cerebral palsy Sinding-Larsen-Johansson syndrome |
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what are the findings in sinding-larsen-johansson syndrome
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Patellar fragmentation, edema anterior to the Hoffa’s fat pad, and proximal patellar tendinosis with thickening and edema are all characteristic findings of Sinding-Larsen-Johansson syndrome. Displacement of the distal patellar pole is unusual.
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what is the difference between patella sleeve avulsion fracture and Sinding-Larsen-Johansson syndrome?
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Patellar sleeve avulsion fracture involves a cartilaginous injury to the inferior pole of the patella. MRI is usually necessary to differentiate from Sinding-Larsen-Johansson syndrome which has similar radiographic findings but represents a pure osseous injury with no cartilage involvement. Distinguishing between these entities is very important for patient management. Minimally or nondisplaced fractures seen with Sinding-Larsen-Johansson syndrome are often managed conservatively, whereas displaced patellar sleeve avulsion fractures usually require open reduction with or without internal fixation and extensor mechanism reconstruction. Osgood-Schlatter disease has the same etiology and presents in a similar population as Sinding-Larsen-Johansson syndrome; however, the process involves the tibial tuberosity.
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mc complication from acl repair
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Patella baja is one of the most common postoperative complications of anterior cruciate ligament repair.
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mc benign bone tumor
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osteochondroma
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Milwaukee Shoulder
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Complete Rotator Cuff Tear
Osteoarthritis Effusion with CPPD Synovial Hyperplasia Cartilage Destruction Osteochondral loose bodies |
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Early OsteoArthritis
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Epiphyseal Dysplasia
Ochronosis Acromegaly |
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3 Types of Osteoid Osteomas
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Cortical (=nidus in cortex): has solid/laminated periosteal reaction radiolucent center (nidus) ± central osteosclerosis
Cancellous (=intramedullary): intraarticular lesion, difficult to identify; little osteosclerosis; widened joint space Subperiosteal (rare): round soft-tissue mass adjacent to bone |
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most common cause of protrusio acetabuli
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RA
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Segond Fracture
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represents an avulsion of the lateral capsular ligament. It occurs posterior to Gerdy’s tubercle
a/w ACL tear in 75-100%, a/w meniscal tear in 67%! |
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Terrible Triad of O’donoghue
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ACL Injury
Medial collateral ligament Medial meniscus |
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DDX Ivory Vertebral Body
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“LOST FROM CHOMP”
Lymphoma, Osteopetrosis, Sickle cell disease, Trauma/Tuberculous spondylitis, Fluorosis, Renal osteodystrophy, Osteoblastic metastasis, Myelosclerosis, Chronic sclerosing osteomyelitis / chordoma, Hemangioma, Osteosarcoma, Myeloma, Paget’s disease |
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Diffuse Idiopathic Skeletal Hyperostosis
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Normal mineralization,
flowing ossification of at least four contiguous vertebral bodies, preservation of disc spaces, ossification of multiple tendinous and ligamentous sites in the appendicular skeleton, absence of joint abnormalities, sporadic distribution primarily in the spine |
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Tumoral Calcinosis
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large soft tissue calcifications,
separate from the bone, overlying multiple joints. Note that many of these lesions are clearly extra-articular, which excludes synovial osteochondromatosis Key finding on the upright film is that of a fluid-fluid level, which clinches the diagnosis. Uptake on a bone scan is common in this condition |
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DDX Dense Bones
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“Regular Sex Makes Occasional Perversions Much More Pleasurable And Fantastic”
Renal Osteodystrophy, Sickle Cell, Myelofibrosis, Osteopetrosis, Pyknodysostosis, Metastases, Mastocytosis, Paget’s Dz, Athelete, Fluorosis |
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How to tell apart the causes of increased bone density:
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Hyperparathyroidism = renal cause
Small spleen = sickle cell disease Big spleen = mastocytosis or myelofibrosis Bone within bone = osteopetrosis Acro-osteolysis = pyknodysostosis Mixed with destruction = metastases Expanded bone = Paget’s |
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DDX Acro-osteolysis
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PETER’S DIAPER SPLASH”
Psoriasis, Porphyria, Ehlers-Danlos, Thrombangitis obliterans, Ergot therapy, Raynaud’s, Scleroderma, Diabetes, Dermatomyositis, Dilantin Rx, Injury (e.g., thermal), Arteriosclerosis obliterans, PVC worker, Rheumatoid arthritis, Reiter’s, Sarcoid, Progeria, Pyknodysostosis, Leprosy, Lesch-Nyhan, Absence of pain, Syringomyelia, Hyperparathyroidism |
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CREST syndrome:
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Calcinosis of skin,
Raynaud’s, Esophageal dysmotility, Sclerodactyly Telangiectasia |
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Dense Metaphyseal Bands
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DENSE LINES”
D-vitamin intoxication, Elemental arsenic & heavy metals, Normal variant, Systemic illness, Estrogen to mother during pregnancy, Leukemia, Infection (TORCH), Never forget healed rickets, Early hypothyroidism, Scurvy, congenital Syphilis, Sickle Cell Disease |
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Signs of a ligamentum teres tear
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discontinuity,
thickening or thinning of the ligament, intrasubstance signal abnormality |
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What labs are elevated in dermatomyositis? |
Aldolase, transaminases, CPK, and LDH |
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What are the three primary stabilizers of the Posterolateral Corner in the knee? |
The three primary stabilizers are the popliteofibular ligament, fibular collateral ligament, the popliteus tendon. |
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What lesions may be a/w secondary ABC (Aneurysmal Bone Cysts)? |
GCT Osteoblastoma Chondroblastoma |
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CT findings in Necrotizing Fasciitis? |
The CT findings of subcutaneous emphysema, multispace involvement, soft-tissue pockets of fluid, and marked asymmetric soft-tissue edema are most consistent with necrotizing fasciitis. |
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Predisposing factors for necrotizing fasciitis? |
Alcoholism, diabetes mellitus, immunosuppression, minor trauma, male gender, advanced age, intravenous drug abuse, prolonged hospitalization, and indwelling catheters. |
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MCC necrotizing fasciitis? |
Necrotizing fasciitis is most commonly polymicrobial involving Clostridium, Proteus, Escherichia coli, Bacteroides, and/or Enterobacteriaceae |
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Which muscles reside in the deep and superficial posterior compartments of the leg? |
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MC Meniscal Tear |
The posterior horn of the medial meniscus is the most common site of meniscal tears. |
