DIFFERENTIAL DIAGNOSIS MUSCULOSKELETAL OF DISORDERS

DIFFERENTIAL.DIAGNOSTIC OF BONE GAMUT DISORDERS

DELAYED BONE AGEA. CONSTITUTIONAL 1. Fami l i al 2. IU GR B. METABOLIC 1. Hypopituitarism 2. Hypothyroidism (Turner 3. Hypogonadism syndrome) 4. Cushingdisease,steroidtherapy 5. Diabetes mellitus 6. Rickets 7. Malnutrition 8. lrradiation brain (for cerebraltumor/ ALL) of C. SYSTEMIC DISEASE 1. Congenital heartdisease 2. Renaldisease 3. Gl disease:celiacdisease, Crohndisease, ulcerative colitis 4. A nemi a 5. Bone marrowtransplantation years of age) (1.5times lesion(= greatest r/ elongated the leastdiameter): Ewingsarcoma,histiocytic angiosarcoma lymphoma, chondrosarcoma, ri scleroticmargin(= r?ctionof host tissueto tumor)

Marrow to TumorsLocalizing Hematopoietic1. 2. 3. 4. Metastases Plasmacell myeloma Ewingsarcoma lymphoma Histiocytic

Plane TumorPositionin TransverseLESION A. CENTRALMEDULLARY 1. E nc hon d ro ma 2. Solitarybone cyst L ME B . E CCE NTR IC D U L L AR Y E SION 1. G iantce l ltu m o r 2. Osteogenic sarcoma,chondrosarcoma, fibrosarcoma fibroma 3. Chondromyxoid LESION C. CORTICAL fibroma 1. Nonossifying 2. Osteoidosteoma LESION D. PERIOSTEAL JUXTACORTICAL / / 1. Juxtacortical chondroma osteosarcoma 2. Osteochondroma sarcoma osteogenic 3. Parosteal

Diffuse BoneMarrow Abnormalities in ChildhoodBY A. REPLACED TUMORCELLS (a) metastatic disease (in 1. Neuroblastoma Youngchild) (in 2. Lymphoma olderchild) (in 3. Rhabdomyosarcoma olderchild) (b) primaryneoplasm 1. Leukemi a BY B. REPLACED RED CELLS = Red cell hyperplasia = reconversion (a) severeanemia: sicklecell disease, hereditary spherocytosis thalassemia, (b) chronicsevereblood loss

Differential Diagnosis Musculoskeletal of Disorders(c) marrow replacement neoplasia by (d)treatment granulocyte-macrophage with colony stimulating factor C. REPLACED FAT BY = 1. Myeloid depletion aplastic anemia D. REPLACED FIBROUS BY TISSUE 1. Myelofibrosis Age Incidenceof Malignant Bone Tumors 0 80%of bonetumors correctly are determined the on basis agealone! of Age [years]0.1 0.1-10 10 -30 30 -40

SARCOMAS AGE: BY mnemonic; "Every OtherRunner Feels Grampy PainOn Moving" Ewingsarcoma Osteogenic sarcoma Reticulum sarcoma cell Fibrosarcoma Chondrosarcoma Parosteal sarcoma Osteosarcoma Metastases

0 -10 years 10-30years 20-40 years 2040 years 40-50 years 40-50 years 60-70 years 60-70 years

TumorNeuroblastoma Ewingtumorin tubularbones(diaphysis) (metaphysis); Osteosarcoma Ewingtumor in flat bones Reticulum cell sarcoma(similarhistology to Ewingtumor);fibrosarcoma; malignant giantcelltumor(similar histology to fibrosarcoma)parosteal sarcoma; ; lymphoma Metastatic carcinoma; multiplemyeloma; chondrosarcoma R OU N DC E LLTU MOR S : { arise in midshaft r/ osteolytic lesion ! reactivenew bone formation r/ no tumor new bone mnemonic; "LEMON" Leukemia, Lymphoma Ewingsarcoma, granuloma Eosinophilic Multiple myeloma Osteomyelitis Neuroblastoma

>40

Osteosarcoma Chordoma Myelomq Chondrosarcoma Lymphoma Adamantinoma

Metastases

ignant fibrous histiocytoma

Extraosseoussarcoma

Osteosarcoma

Ewing sarcoma Neuroblastoma Age

10

20

30

Fibrous cortical defect, Eosinophilic granuloma desmoid, Nonossifying fibroma, Desmoplastic fibroma, Chondroblastoma Osteoid osteoma, Chondromyxoid fibroma, Enchondroma

ABcrc\Cortical Osteoblastoma

Giant cell tumor

Average Age for Occurrence of Benign and Malignant Bone Tlrmors

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INVOLVEMENT WITH SOFT-TISSUE MALIGNANCY mnemonic.' "My MotherEats ChocolateFudgeOften" Metastasis Myeloma Ewingsarcoma Chondrosarcoma Fibrosarcoma Osteosarcoma

Tumors of Fatty Tissue OriginA . B E N IGN liPoma 1. Intraosseous lipoma 2. Parosteal B. MALIGNANT liPosarcoma 1. Intraosseous of followthe signalintensity subcutaneous 0 Lipomas fat in all sequences!

TumorMatrixof BoneTumors ng Cartilage-formi Bone Tumors/ { centrallylocatedringlike/ flocculent flecklike radiodensities A. BENIGN 1. E nc ho n d ro m a 2. Parosteal chondroma 3. Chondroblastoma fibroma 4. Chondromyxoid 5. Osteochondroma B. MALIGNANT 1. Chondrosarcoma 2. Chondroblastic osteosarcoma

Tumors of VascularOrigin1 year old prosthesis asepticloosening scintigraphy: bone-gallium Sequential of r/ congruentspatialdistribution both tracerswith galliumintensity lessthan bonetracer= no infection of incongruentintensity gallium / { spatially exceedsthat of bone agent = infection of congruent+ similarintensity both { spatially tracers= inconclusive

HIP Snapping Hip Syndrome A. INTRAARTICULAR 1. Osteocartilaginous bodies = B. EXTRAARTICULAR tendonslippage 1. fascialata lgluteusmaximus overgreater trochanter 2. iliopsoas tendonover iliopectineal eminence 3. longheadof bicepsfemorisover ischial tuberosity portion hip 4. iliofemoral ligament of over anterior capsule

Increase Teardrop in Width^/ increasein distancebetweenteardrop+ femoralhead Cause: hip joint effusion r/ increasein mediolateral size of teardrop Cause: hip dysplasia, chronichipjointeffusion maturation duringskeletal

Protrusio Acetabuli= acetdbular floorbulgingintopelvis line medially ilioischial by line to r/ acetabular projecting >3 mm (in males)/ >6 mm (in females) r/ crossingof medial+ lateralcomponents pelvic of "teardrop" (U-shaped radiodense area medialto hip joint with (a) lateralaspect= acetabular articular marginof surface(b) medialaspect= anteroinferior quadrilateral surfaceof ilium) A. UNI LA T E RAL 1. Tuberculous arthritis 2. Trauma dysplasia 3. Fibrous B. BILATERAL 1. Rheumatoid arthritis 2. Pagetdisease 3. Osteomalacia mnemonic,' "PROT" Pagetdisease Rheumatoid arthritis (HPT) Osteomalacia Trauma

Pain with Hip Prosthesis per Approximately 120,000 arthroplasties year in hip USA 1. Heterotopic ossification 2. Trochanteric bursitis fracture/ periprosthetic fracture/ cement 3. Prosthetic fracture (dueto capsular laxity/ incorrect 4. Dislocation placement) component

Differential Diagnosis of Musculoskeletal Disorders

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Combined labeledleukocyte-m arrowscintigraphy : Accuracy: >90/" Concept: Tc-99msulfurcolloidmaps aberrantly located normal bone marrowas a point of reference leukocyte for tracer r/ spatiallycongruent distribution both of radiotracefs= fto infection r/ tabeledleukocyte activitywithoutcorresponding = sulfurcolloidactivity infection Arthrography: r/ irregularity joint pseudocapsule of ^/ tiltingof nonbursal spaces/ sinustracts/ abscesscavities Aspiration fluid underfluoroscopy (12-93% of sensitive,83-92% specificfor infection): r/ injection contrastmaterialto confirm of intraarticular location

= 4. Lateral acetabular inclination horizontal version = ongleof cup in reference line R (40' + 10o to desirable) Lessangulation: stablehip, limited abduction Greater angulation: riskof hip dislocation 5. Varus/ neutral/valgusstem position Varusposition: tip of stem restsagainstlateral increased risk for endosteum, loosening Valgusposition: tip of stem restsagainstmedial endosteum, a significant not problem (15' + 10' desirable) 6. Acetabular anteversion = lateralradiograph groin of Retroversion: riskof hip dislocation 7. Femoralneck anteversion works synergistically acetabular with anteversion true angleassessed CT by

Evaluation TotalHip Arthroplasty ofM E A S URE MEN T S Reference line: transischial tuberosity line (R) position acetabular 1. Leg length= vertical of component = corTlplfing of greater/ lessertuberosity level (T) with respectto line R High placement: shorterleg, less effective muscles crossing hipjoint the Low placement: longerleg,muscles stretched to pointof spasmwith risk of dislocation 2. Verticalcenterof rotation = distance from centerof femoralhead (C) to line R 3. Horizontal centerof rotation = distancefrom centerof femoralhead (C) to teardrop othermediallandmark / Lateralposition: iliopsoas tendoncrossesmedial to femoralheadcenterof rotation increasing risk of dislocation Radiographic findings A . N OR MA L r/ irregular interface cement-bone = norfi'rll interdigitation of polymethylmethacrylate MA) with (PM providing bone remodeling adjacent a mechanical interlock 0 P MMAi s not a gl ue! r/ tfrinlucentlinealongcement-bone interface = 0.1-1.5-mm nconnecti ve ssuemem br ane thi ti ("demarcation") along cement-bone interface accompanied thin lineof bonesclerosis by B . A B N OR MA L r/ wide lucentzone at cement-bone interface = )2-mm lucentlinealongbone-cement interface due to granulomatous membrane + Cause: componentloosening reaction to particulate debris(eg, PMMA, colyethylene)

Initial Evaluation of Total Hip Arthroplasty

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r/ lucentzone at metal-cement interface along proximallateralaspectof femoralstem = suboptimal metal-cement contactat time of surgery loosening / r/ well-defined area of bone destruction (= histiocytic response, aggressive granulomatous disease) reactionas response Cause: granulomatous to particulate debris/ infection tumor / positioning femoralheadwithin of { asymmetric acetabular component wear / dislocation of Cause: acetabular femoralhead / acetabular disruption / linerdisplacementdeformity / { cementfracture Cause: loosening

KNEE BoneContusionPatternr/ edema of midportion lateralfemoralcondyle of Cause: pivot shift injury = volgusload + external rotationof tibia/ externalrotationof femur appliedto variousstatesof flexion (noncontact injury) combined Predisposed: skier,footballplayer Associated with injury of: (1) anterior > lig. cruciate (midsubstance femoral > attachment tibialattachment site) joint capsule+ arcuateligament (2) posterior (3) posterior hornof lateral/medialmeniscus (4) medialcollateral ligament patellarsurface r/ + edemaof posterior Cause: dashboard injury = force upon anterior proximal tibiawith knee in flexedposition Associated with: (1) rupture posterior > lig. of cruciate (midsubstance femoralattachment tibialattachment > site) joint capsule (2) tear of posterior (3) fracture/ osteochondral injuryof patella (4) injuryof hip rl "kissing" bone contusionpattern= anterioraspectof tibialplateau+ anterioraspectof femoralcondyle Cause: hyperextension injury = directforce upon anterior tibiawhilefoot is planted indirect / force of forcefulkickingmotion Associated with: (1) injuryto posterior anterior lig. / cruciate (2) meniscal injury (3) dislocation knee of (4) popliteal injury neurovascular (5) completedisruption posterolateral complex of ./ edema in lateralaspectof femoralcondyle (secondary directblow) to { smallarea of edemain medialfemoralcondyle(due ligament) to avulsivestressto medialcollateral Predisposed: footballplayer Cause: clip injury = pure valgusstresswith knee in mildflexion

Associated with injury of: (at (1) medialcollateral ligament femoral site attachment (2) anteriorcruciateligament (3) medialmeniscus (4) combination all three= O'Donoghuetriad of aspectof lateralfemoralcondyle { anterolateral ^/ inferomedial aspectof patella Predisposed: teenaged/ young adult athleteswith groove shallow trochlear Cause: lateral patellar dislocation = twisting motionwith knee in flexion+ quadriceps contraction Associated with injury of: (1) medi al reti nacul um (nearfemoral ligament (2) medialpatellofemoral stabilizing site) most important attachment structure) (3) medialpatellotibial ligament

TibialLesions Unique1. Fibrous dysplasia fibroma 2. Ossifying 3. Adamantinoma

Tibiotalar Slanting= downwardslantingof medialtibialplafond 1. Hemophilia 2. Stilldisease 3. Sicklecell disease 4. Epiphyseal dysplasia 5. Trauma

FOOT AbnormalFoot PositionsA. FOREFOOT 1, Varus= adduction = ?XiS 1st metatarsal deviatedmediallyrelative of to axis of talus 2. Valgus= abduction = ?Xisof 1st metatarsal relative deviatedlaterally to axis of talus = 3. Inversion supination = inwardturningof sole of foot = 4. Eversion pronation = outwardturningof sole of foot B . H IN D FOOT of talipes(talus,pes) = any deformity the ankle and hindfoot 1. Equinus = hindfootabnormality with reversalof calcaneal pitchso that the heelcannottouchthe ground foot 2. Calcaneal = vfY high calcanealpitchso that forefoot cannottouchthe ground 3. Pes planus= flatfoot = low calcaneal pitch+ (usually) heelvalgus+ forefooteversion 4. Pes cavus = high calcanealpitch (fixedhigh arch)

Differential Diagnosis Musculoskeletal Disorders 25 of = Clubfoot TalipesEquinovarusCommonseverecongenital deformity characterized by . equinusof heel (reversed calcanealpitch) . heel varus (talocalcaneal angleof almostzero on AP view with both bonesparallelto each other) . metatarsus adductus(axisof 1st metatarsal deviated mediallyrelative axis of talus) to 1. Arthrogryposis multiplex congenita punctata 2. Chondrodysplasia 3. Neurofibromatosis 4. Spinabifida 5. Myelomeningocele

SOFTTISSUES HistologicClassification Soft-tissue Lesions of A. FATTY1. Lipoma 2. Angiolipoma 3. Liposarcoma FIB R OU S 1. Fi broma fasciitis 2. Nodular fibromatosis desmoid 3. Aggressive / 4. Fibrosarcoma MUSCLE 1. Rhabdomyoma 2. Leiomyoma 3. Rhabdomyosarcoma 4. Leiomyosarcoma VASCULAR 1. H emangi oma 2. Hemangiopericytoma 3. Hemangiosarcoma LY MP H 1. Lymphangi oma 2. Lymphangiosarcoma 3. Lymphadenopathy lymphoma metastasis in / SYNOVIAL 1. Nodular synovitis 2. Pigmented villonodular synovitis 3. Synovialsarcoma NEURAL 1. Neurofibroma 2. N euri l emoma 3. Ganglioneuroma neuroblastoma 4. Malignant 5. Neurofibrosarcoma A C A R TILA GE N D B ON E 1. Myositis ossificans 2. Extraskeletal osteoma 3. Extraskeletal chondroma 4. Extraskeletal chondrosarcoma 5. Extraskeletal osteosarcoma

B.

C.

Rocker-bottom Foot = VerticalTalusr/ vertically orientedtaluswith increased talocalcaneal angle on lateralview joint { dorsalnavicular dislocation talonavicular at r/ heetequinus { rigiddeformity Associatedwith: Arthrogryposis multiplex congenita; spinabifida; trisomy13-18 D.

E.

TalarBeak= Hypertrophied TalarRidge1. 2. 3. 4. Talocalcaneal type of tarsalcoalition Diffuse idiopathic (DISH) skeletal hyperostosis Acromegaly Rheumatoid arthritis F.

Heel Pad Thickening = heelpad thickening >25 mm (normal 21-27th week GA): OB-US (diagnosable longbones: femurlength of r/ shortening proximal between21 and 27 weeks MA 25 mm @ Joints r/ premature (commonly osteoarthritis knees)

Homozygous Achondroplasia= hereditary autosomal dominantdiseasewith severe featuresof achondroplasia (disproportionate limb shortening, more markedproximally than distally) Risk: marriageof two achondroplasts each other to ^/ largecraniumwith short base + smallface { flattenednose bridge r/ short ribs with flaredends r/ hypoplastic vertebralbodies r/ decreasedinterpedicular distance r/ shortsquaredinnominate bones r/ flattenedacetabularroof { small sciaticnotch r/ short limb boneswith flaredmetaphyses r/ short,broad,widelyspacedtubularbones of hand Prognosis; oftenstillborn; lethalin neonatalperiod (fromrespiratory failure) DDx: thanatophoricdysplasia

ACROC EPHALOSYN DACTYLY= syfldromecharacterized by (1) increased heightof skullvaultdue to generalized craniosynostosis ocrocephaly, (= oxycephaly) (2) syndactyly fingers/ toes of

ACTINOMYCOSIS= chronicsuppurative infection characterized formation by of multiple abscesses, draining sinuses, abundant granulation tissue Organism; Actinomyces israelii, Gram-positive anaerobicpleomorphic small bacterium with proteolytic activity, superficially resembling the morphology a hyphalfungus(Gomori of methenamine silverstain-positive filaments); closelyrelatedto mycobacteria Histo: mycelialform in tissue;rod-shaped bacterial form normally inhabiting (dental oropharynx caries, gingivalmargins,tonsillarcrypts)+ Gl tract Predisposed: individuals with very poor dentalhygiene, immunosuppressed patients Location: mandibulofacialintestinal lung > > Types: (1) Mandibulo- cervicofacial / (55%) actinomycosis poor oral hygiene Cause:

TypeI Typell Typelll TypelV TypeV

Apertsyndrome= ?crocephalosyndactyly Vogt cephalosyndactyly Acrocephalosyndactyly asymmetry skull with of + mild syndactyly Wardenburg type Pfeiffer type

ACROOSTEOLYSIS, FAMILIAL dominant inheritance Age: onsetin 2nd decade; M:F = S:1 . sensorychangesin hands+ feet . destruction nails of . joint hypermobility ' swellingof plantarof foot with deep wide ulcer+ ejection of bone fragments

. draining sinuses cutaneous . "sulfur of granules" sputum/ exudate= colonies in organismsarrangedin circularfashion= mYGelial clumpswith thin hyphae1-2 mm in diameter of { osteomyelitis mandible(mostfrequentbone of involved) with destruction mandiblearound tooth socket r/ no new-boneformation { spreadto soft tissuesat angle of jaw + into neck (20%) (2) Abdominopelvic ileocecal actinomycosis / Cause: rupture/ surgeryof appendix;IUD use to localized cecum/ appendix Location; initially . fever,leukocytosis, anemia mild . weightloss,nausea, pain vomiting, . c hr onic i n u si n g ro i n s (resembling Crohn + ri totO thickening ulcerations disease) appendix) viscus(usually r/ rupture abdominal of ^/ fistulaformation psoas r/ abscessin liver (15%),retroperitoneum, yellow"sulfurgranules" muscle(containing = 1-2-mm colonyof gram-positive bacilli) (1 (3) Pleuropulmonary actinomycosis 5%) of Cause: aspiration infectedmaterialfrom sPread / oropharynx hematogenous Predisposed: alcoholics containing massesof PMN leukocytes Histo: / roundactinomycoticsulfurgranules tissue by surrounded a rim of granulation @ Lung . draining through chestwall sinuses(spread fascialplanes) r/ enhancingextensive chronic transfissural (acuteairspace consolidation segmental + pneumonia rare);usuallyunilateral upper lobe predominance with ringlike { cavitarylesion(abscess) enhancement r/ fibroticpleuritis i effusion empyema r/ chronicpleural CT: within { centralareas of low attenuation consolidation pleural thickening { adjacent / bacterial fungal tuberculosis, DDx: carcinoma, pneumonia @ Vertebra+ ribs of r/ destruction vertebrawith preservation disk of abscesswithout + smallparavertebral (DDx to tuberculosis:disk calcification large abscesswith calcium) destroyed, r/ thickening cervicalvertebrae aroundmargins of of / r/ destruction thickening ribs (a) Mixedorgans(10%) @ Tubularbonesof hands type lesionof mottledpermeating r/ destructive erosive + destruction subarticular r/ cartilage TB) defectsin joints(simulating @ Skin,brain,pericardium + dr6bridementpenicillin Rx: surgical

ADAMANTINOMA= (MALTGNANT) ANGIOBLASTOMA lesion = locally / aggressive malignant cell Histo: pseudoepithelial masseswith peripheral columnarcells in a palisadepailernwith varying amountsof fibrousstroma;areasof squamous/ tubular/ alveolar/ vesseltransformation; ameloblastoma prominentvascul arity; resembles of the jaw Age: 25-50 years,commonestin 3rd-4th decade . frequently historyof trauma . l ocal sw el l i ng P ai n + middle113 tibia(90%),fibula,ulna,carpals, of Location: shaftof femur humerus, metacarpals, margin, lesionwith sclerotic roundosteolytic r/ eccentric with majorlesion foci may have additional in continuity (cHARACTERISTIC) ^i may show mottleddensity frequent rl bone expansion { oftenmultiple after Prognosis; tendencyto recurafter localexcision; pulmonary metastases severalrecurrences may develoP related) DDx: fibrousdysplasia(possibly A IN H U M D IS E A S E = DACTYLOLYSIS SPONTANEA = fissure, saw,sword] [ainhum Etiology: unknown of with fibroticthickening epidermis Histo: hyperkeratotic below;chroniclymphocytic bundles collagen arterialwalls may be present; reaction inflammatory vessellumina with narrowed may be thickened Incidence: up Io 2"1" Age: usuallyin malesin 4th + 5th decades;Blacks M (WestAfrica)+ their Americandescendants; > F ' deep soft-tissue grooveformingon medialaspectof plantarsurfaceof proximalphalanxwith edemadistatly . painfululceration maYdeveloP Location: mostlysth / 4th toe (rarelyfinger);near joint; mostlybilateral interphalangeal of progressive ./ sharplydemarcated bone resorption phalanx of withtapering proximal distal/ middlephalanx (afteran averageof 5 years) to completeautoamputation i osteoporosis of Rx: earlysurgicalresection groovewith Z-plasty (diabetes, leprosy, disorders DDx: (1) Neuropathic sYPhilis) (2) Trauma (burns,frostbite) arthritis, from inflammatory (3) Acroosteolysis polyvinyl chlorideexposure infection, bands in amnioticband (4) Congenitally constricting syndrome AMYLOIDOSIS diversegroup of = extracellular of deposition a chemically in proteinpolysaccharides body tissues tends (Br-microglobulin); to form aroundcapillaries cellsof largerbloodvesselscausing + endothelial with vascular obliteration infarction ultimately

Boneand Soft-Tissue Disorders 43= serumprotein Fr-microglobulin low-molecular-weight not filteredby standarddialysis membranes Path: stainswith Congo red At risk: patientson long-term hemodialysis . bone pain (eg,shoulder pain) . periarticular rubberysoft-tissue swelling+ stiffness (shoulders, hips,fingers) . carpal-tunnel syndrome(commonly bilateral) . BenceJones protein(withoutmyeloma) 1. Synovial-articular pattern= amVloid arthropathy Location: cervicalspine,hip, shoulder,elbow r/ juxtaarticular soft-tissue swelling(amyioiddeposited jointcapsule, in synovium, tendons, ligaments) + extrinsic osseous erosion r/ mild periarticular osteoporosis r/ subchondral cysts + well,defined scleroticmargin ^/ loint space preserveduntil late in courseof disease r/ subluxation proximal humerus+ femoralneck of MR: { extensive deposition abnormalsoft tissueof low of to intermediate signalintensity TlWl + T2Wl on coveringsynovialmembrane, filfingsubchondral defects,extendinginto periarticular tissue ./ loint effusion DDx: inflammatory arthritis 2. Diffusemarrowdeposition j generalized osteoporosis ri coarsetrabecular pattern(DDx: sarcoidosis) r/ pathologic collapseof vertebralbody may occur 3. Localized destructive lesion(rarestform) Location: appendicular axialskeleton > ./ focal medullary lytic lesionwith endostealscalloping (+ secondaryinvasion+ erosionof articular bone) = amyloidoma Cx: pathologicfracture Types: 1. IN TR A OS S E OUA B C S = primarycystic/ telangiectatic tumor of giant cell family,originating bone marrowcavity,slow in expansion cortex;rarelyrelatedto historyof of trauma 2. EXTRAOSSEOUS ABC = posttraumatic hemorrhagic cyst; originating on surfaceof bones,erosionthroughcortexinto marrow Age: peak age 16 years (range 10-30 years); i n 7 5 h < 2 0 y e a r s ;F > M . pain of relatively acute onsetwith rapid increaseof severityover 6-12 weeks . t historyof trauma . neurologic signs(radiculopathy quadriplegia) in to if spine Location: (a) spine (12-30%)with slightpreditection for posterior elements; > thoracic lumbar> cervicalspine (22%);involvement of vertebralbody (40-90%);may involvetwo contiguous vertebra (25%) e (b) long bones: eccentricin metaphysis of femur,tibia,humerus, fibula;pelvis { purelylyticeccentricradiolucency r/ aggressive expansileballooning lesionof "soap-bubble" pattern+ thin internaltrabeculations r/ rapid progression within6 weeks to 3 months r/ scleroticinner portion { almostinvisible thin cortex(CT shows integrity) r/ tumor respectsepiphyseal plate { no periosteal reaction(exceptwhen fractured) CT: r/ "blood-filled sponge"= fluid-fluid hematocrit i levels due to bloodsedimentation 10-35%) (in MR: r/ multiplecysts of differentsignalintensity representing differentstagesof bloodby-products , ! low-signal intensity = intactthickenedperiosteal rim membrane NUC: r/ "doughnut sign" = peripheral increased uptake(64%) A ngi o: r/ hypervascularity lesionperiphery(in 7S%) in Prognosis: 20-30/" recurrence rate Rx: preoperative embolotherapy; completeresection; radiation therapy(subsequent sarcomapossible) Cx: (1) pathologic fracture(frequent) (2) extradural blockwith paraplegia DDx: (1) Giantcelltumor(particularly spine) in (2) Hemorrhagic cyst (end of bone / epiphysis, not expansile) (3) Enchondroma (4) Metastasis (renalcell + thyroidcarcinoma) (5) Plasmacytoma (6) Chondro-and fibrosarcoma (7) Fibrousdysplasia (8) Hemophilic pseudotumor (9) Hydatidcyst

ANEURYSMAL BONECYST= eXponSile lesionof bone containing thin-walled bloodfilledcysticcavities;name derivedfrom roentgen appearance Etiology: (a) primaryABC (65-99%) localcirculatory disturbance a resultof trauma as (b) secondary ABC (1-95%) arisingin preexisting bonetumorcausing venous obstruction arteriovenous / fistula:giantcelltumor (39%),osteoblastoma, chondroblastoma, angioma, telangiectatic osteosarcoma, solitarybone cyst, fibrousdysplasia, xanthoma, chondromyxoid fibroma,nonossifying fibroma,metastatic carcinoma Histo: "intraosseous arteriovenous malformation,, with honeycombed spacesfilledwith blood + linedby granulation tissue/ osteoid;areas of free hemorrhage; sometimes multinucleated giant cells;solidcomponentpredominates S-7% in

Radiology Review Manual

ANGIOMATOSIS = diffuseinfiltration bone / soft tissueby of lesions / hemangiomatouslymphangiomatous Age: first 3 decadesof life May be associated with: lymphedema, chyloperitoneum, chylothorax, cystichygroma hepatosplenomegaly, (30-40%) A. OSSEOUSANGIOMATOSIS . indolent course Location: femur > ribs > spine > pelvis> humerus> scapula> other long bones > clavicle ("hole/ with honeycomb latticework { osteolysis appearance within-hole") { may occur on both sides of ioint DDx: solitaryosseoushemangioma B. CYSTICANGIOMATOSIS = extensiveinvolvement bone of cystsin bone Histo: endothelium-lined Age: peak 10-15 years;rangeof 3 monthsto 55 Years Location: longbones,skull,flat bones r/ multipleosteolytic lesionsof 1-2 mm to metaphyseal severalcm with fine scleroticmargins+ relative cavity sparingof medullary of rl may show overgrowth long bone thickening r/ endosteal with soft{issue mass r/ sometimesassociated + phleboliths { chylouspleuraleffusionsuggestsfatal prognosis diseasessuch as) DDx: (otherpolyostotic metastases, X, histiocytosis fibrousdysplasia, fibromatosis, disease, congenital Gaucher Maffucisyndrome,neurofibromatosis, enchondromatosis

(60-70%) ANGIoMATOSIS c. soFT-TrssuE= VISCERAL ANGIOMATOSIS

. poor prognosis SYNDROMES D. ANGIOMATOUS 1. Maffuci syndrome syndrome 2. Osler-Weber-Rendu disease 3. Klippel-Trenaunay-Weber syndrome 4. Kasabach-Merritt 5. Gorhamdisease

ANGIOSARCOMA= aggressive with frequentlocal vascularmalignancy + recurrence distantmetastasis by Histo: vascularchannelssurrounded cellular / hemangiomatous lymphomatous with highdegreeof anaplasia elements Age: M : F = 2: 1 Associatedwith: Stewart-Treves syndrome = angiosarcoma developing with chroniclymphedema patients in postmastectomy Location: skin (33%);soft tissue (24%\; bone (6/"):tibia(23%),femur(18%), (13%),pelvis(7%) humerus hemangiopericytoma DDx: hemangioendothelioma,

AN KYLOSING SPONDYLITIS primarily = autoimmune etiology diseaseof unknown affectingaxialskeleton A ge: 15-35years;M:F = 3:1-10:1 ; = Caucasians:Blacks3:1 colitis,regionalenteritis with: (1) ulcerative Associated (2) iritisin 25% + (3) aorticinsufficiency atrioventricular conductiondefect . HLA-B27 positivein 96% . insidious onset of low back pain + stiffness joints and sites of Path: involvessynovial+ cartilaginous attachment ligamentous Location: (a) axialskeleton:sacroiliac ioints,thoracolumbar junctions + lumbosacral jointinvolvement! is 0 HALLMARK sacroiliac n (b) peripheral skeleto (10-20%): sternaljoint, joint pubis,hip,glenohumeral symphysis femur in insertions pelvis+ proximal (c) tendinous joints of abnormalities sacroiliac course: initial Temporal junction with gradual + thoracolumbar of of involvement remainder sPine S kul l @ joint erosions, { temporomandibular spacenarrowing, osteophytosis @ Hand (30%) MCP, PlP, DIP Targetarea: osseousproliferation { exuberant joint space narrowing, osseous { osteoporosis, than in rheumatoid less (deformities striking erosions arthritis) joint/ symphysis pubis @ Sacroiliac on of sclerosis joint marginsprimarily iliac { initiatty + side (bilateral symmetriclate in disease,may be early in disease) + unilateral asymmetric + { later irregularities wideningof joint (cartilage destruction) r/ bony fusion @ Pelvis "whiskering":ischialtuberosity, iliaccrest, { periostitic external rami,greaterfemoraltrochanter, ischiopubic calcaneus occipitalprotuberance, @ Spine / { squaring= straightened convexanteriorvertebral margins= erosiveosteitisof anteriorcorners of { "shinycorner"= Ieactivesclerosis cornersof vertebralbodies = of rl disXitis erosiveabnormalities diskovertebral junction = ./ .diskalballooning" biconvexshape of intervertebral + deformity diskal disk relatedto osteoporotic calcification formation= thin vertical { marginalsyndesmophyte spiculesbridgingthe vertebralbodies radiodense fibrosus = ossification outerfibersof annulus of ligament) (NOT anteriorlongitudinal contour ./ "bamboo spine"on AP view = undulating due to syndesmoPhYtosis Cx: proneto fractureresultingin pseudarthrosis

Boneand Soft-Tissue Disorders 45{ asymmetric erosions laminar spinousprocesses of + of lumbarspine r/ ossification supraspinous interspinous of + ligaments: = r/ "dagger Sign" singleradiodense on AP view line r/ "trolley-track" on AP view = centralline of sign ossification with two laterallinesof ossification joint capsules) (apophyseal r/ apophyseal costovertebraljoint + ankylosis(on obliqueviews) ! dorsalarachnoid diverticula lumbarspinewith in erosionof posterior elements(Cx: cauda equina syndrome) r/ atlantoaxial subluxation @ Chest lncidence: 1o/o patientswith ankylosing ol spondylitis Histo: interstitial pleuralfibrosiswith foci of dense + collagen deposition, granulomas NO . bone manifestations obvious+ severe Location: apices/ upper lungfields joint irregularities sclerosis r/ sternomanubrial + ./ uni- / bilateral coarseupp-er lobe pulmonary fibrosis with upwardretraction hila (DDx: tuberculosis) of progressively ! reticulonodular confluentopacitiesin lung apices { apicalbullae+ cavitation (mimicking TB) HRCT: r/ peripheral interstitial lung disease r/ bronchiectasis ./ paraseptal emphysema r/ apicalfibrosis Cx: superinfection, especially with aspergillosis (mycetoma formation) atypicalmycobacteria / DDx: othercausesof pulmonary apicalfibrosis (primary infection fungi/ mycobacteria; by cancer) @ Cardiovascular 1. Aortitis (5%) of ascendingaorta + aortic valve insufficiency Prognosis: 20/o progressto significant disability; occasionally deathfrom cervicalspine fracture/ aortitis DDx: (1) Reitersyndrome (unilateral asymmetric Sljoint involvement, paravertebral ossifications) (2) Psoriatic (unilateral arthritis asymmetric Sljoint involvement, paravertebral ossifications) (3) Inflammatory boweldisease (4) Sternocostoclavicular hyperostosis (pustulosis palmariset plantaris) ! thickening posterior of tibial+ fibularcortices ! minorradioulnar bowing r/ kyphoscoliosis { extensive dural calcification DDx: Lueticsabershin (bowingat lowerend of tibia + anteriorcorticalthickening)

APERT SYNDROME= ACROCEPHALOSYNDACWLY type I

Frequency; 5.5:1,000,000 neonates Etiology: autosomaldominantwith incomplete penetrance; sporadic(in majority) Associated with CNS anomalies: megalocephaly, gyral abnormalities, hypoplastic white matter,heterotopic gray matter,frontalencephalocele, corpuscallosalagenesis,KleeblattschAdel, palate, cleft ventriculomegaly relatedto skull base hypoplasia, (? rarelyprogressive) . lQ variesdepending CNS anomalies 50% normal) (in on . otitismedia(highprevalence) . bifiduvula . conductive hearingloss (commondue to external + middleear malformations) @ Skull . downturned mouth r/ brachycephalic skull (due to coronal craniosynostosis) flat occiput + r/ widenedmetopic+ sagittalsuturesextending from glabellato posterior fontanel(closingbetween2 to 4 years) r/ hypoplastic retrudedmidface: / r/ hypertelorism r/ shalloworbitswith proptosis r/ underdeveloped paranasalsinuses ! underdeveloped maxillawith prognathism ^/ frignpointedarch of palate r/ prominent verticalcrest in middleof forehead (increased pressure) intracranial r/ V-shapedanteriorfossa due to elevation lateral of marginsof lessersphenoid { sellamay be enlarged r/ stylohyoid (38-88%) ligamentcalcification r/ cervical spinefusion(in up to71"/"), commonly of Sth and 6th vertebrae r/ choanalstenosis @ Hand & feet = { severesymmetric syndactyly fusionof distal portionsof phalanges, metacarpals carpals(most / oftenof 2nd, 3rd + 4th digit) r/ absenceof middlephalanges { missing/ supernumerary carpal/ tarsalbones r/ pseudarthroses @ GU (10%) . cryptorchidism ./ hydronephrosis r/ polycystic kidneys(rare) ri bicornuate uterus(rare)

ANTERIOR TIBIALBOWING= WEISMANN-NETTER SYNDROME = coflgnital painlessnonprogressive bilateral anteriorleg bowing Age: beginningin earlychildhood . may be accompanied mentalretardation, by goiter, anemia { anterior bowingof tibia+ fibula,bilaterally, symmetrically at middiaphysis

Radiology Review Manual. respiratory distressdue to reducedthoracicmobility pulmonary infections + (abdominal breathing) frequent . progressive renalfailure+ hypertension @ Chest chest: { markedlynarrow+ elongatedbell-shaped r/ chestdiametersignificantly compared decreased with that of the abdomen r/ normalsize of heartleavinglittleroom for lungs claviclesat levelof 6th cervicalvertebra { horizontal bulbous ribs + irregular { short horizontal junction costochondral @ Pelvis r/ tridentpelvis(retardation ossification triradiate of of cartilage) in { smalliliacwingsflared+ shortened cephalocaudal ("wineglass" diameter Pelvis) { shortischial+ pubicbones spurs angle + acetabular r/ reducedacetabular of ossification capitalfemoralepiphysis ri premature @ Extremities (humerus, femur)= long brachymelia ri rhizomelic + widerthan normal bonesshorter irregularitY { metaphyseal (occasionally) hexadactyly { postaxial of { shortening distalphalanges+ cone-shaped in epiphyses hands+ feet ./ proximalhumeral+ femoralepiphyses ossifiedat birth (frequently) @ Kidneys ri medullary cysticrenaldisease= enlargedkidneys (in on with linearstreaking nephrogram adulthood) OB .U S : r/ proportionate of shortening long bones circumference r/ smallthoraxwith decreased ratio cardiothoracic { increased polydactyly r/ occasionally r/ polyhydramnios failure Prognosis; neonataldeath in 80% (respiratory + infections) Creveldsyndrome DDx: Ellis-van

FISTULA BONE OF ARTERIOVENOUSEtiology: (a) acquired(usuallygunshotwound) (b) congenital Location: lowerextremitymost frequent mass r/ soft-tissue r/ presenceof largevessels (DDx:long-standing varicosity) r/ phleboliths { accelerated bone growth { corticalosteolyticdefect (= pathwayfor large vessels intomedulla) r/ increased bone density

ARTHROGRYPOSIS= ARTHROGRYPOSIS MULTIPLEX CONGENITA = hol'lpfogressive congenital syndromecomplex by characterized poorlydeveloped+ contracted jointswith thickened periarticular muscles, deformed capsuleand intactsensorysystem Pathophysiology: horn / congenital acquireddefectof motor unit (anterior nerves,motorend plates, cells,nerveroots,peripheral of muscle) earlyin fetal lifewith immobilization jointsat variousstagesin theirdevelopment hard agents,toxic chemicals, Cause: ? neurotropic blocking neuromuscular drugs,hyperthermia, mechanical agents,mytoticabnormalities, immobilization lncidence: 0.03% of newborninfants;5% risk of recurrence sibling in in Path: diminution size of musclefibers+ fat depositsin fibrous tissue Associated with: (90%) (1) neurogenic disorders (2) myopathic disorders (3) skeletaldysplasias (myomata, (4) intrauterine limitation movement of amniotic band,twin,oligohydramnios) (5) connective tissuedisorders (46%),lowerextremities only Distribution: all extremities (43%),upperextremities only (11%); joints; joints>> proximal peripheral symmetrical . clubfoot . congenital of dislocation hip . claw hand . diminished musclemass . skin webs r/ flexion+ extension contractures + fractures { osteopepis pathologic of dislocation hip r/ congenital { carpalcoalition r/ verticaltalus valgusdeformity { calcaneal

AVASCULAR NECROSIS = ASEPTIC = AVN= OSTEONECROSIS NECROSIS = corseguenceof interrupted blood supplyto bone with death of cellularelements Histo: (a) cellular leading deathof hematopoietic to ischemia (in cells (in 6-12 hours),osteocytes 12-48 hours) (in and lipocytes 2-5 days) spaces (b) necroticdebrisin intertrabecular cells by and + proliferation infiltration mesenchymal + capillaries on to (c) mesenchymal cells differentiate osteoblasts the new bone synthesizing surfaceof dead trabeculae thickening in layers+ resulting trabecular

ASPHYXIATING THORACIC DYSPLASIA = J E UNE S E A SE DI = autosomalrecessive dysplasia lncidence; 100 cases PDA with: renalanomalies(hydroureter), Associated

Bone and Soft-TiPathogenesis: (1) obstruction extra-and intraosseous of vesselsby arterial embolism, venousthrombosis, traumatic disruption, external (increased compression marrow space pressure) (2) cumulative stressfrom cytotoxic factors Cause: A. Traumaticinterruption arteries of @ femoralhead: 1. Femoralneck fracture(60-75%) 2. Dislocation hipjoint (25%) of 3. Slippedcapitalfemoralepiphysis(15-40%) @ carpalscaphoid: 4-6 monthsafterfracture(in 10-15o/o), in 30-40% of nonunionof scaphoidfracture Site: proximal (mostcommon) fragment head (infrequent) @ humeral B. Embolization arteries of 1. Hemoglobinopathy: sickle-cell disease 2. Nitrogen bubbles:Caisson disease C. Vasculitis 1. Collagen-vascular disease:SLE 2. Radiation exposure D. Abnormal accumulation cells of 1. Lipid-containing histiocytes: Gaucher disease 2. Fat cells: steroidtherapy E. ldiopathic 1. Spontaneous osteonecrosis knee of 2. Legg-Calv6-Perthes disease 3. Freiberg disease mnemonic; "PLASTICRAGS" Pancreatitis, Pregnancy Legg-Perthes disease,Lupus erythematosus Alcoholism, Atherosclerosis Steroids Trauma(femoralneck fracture,hip dislocation) ldiopathic (Legg-Perthes disease), Infection Caisson disease, Collagen disease(SLE) Rheumatoid arthritis, Radiation treatment Amyloid Gaucher disease Sicklecell disease mnemonic: "GlVE INFARCTS" Gaucherdisease ldiopathic (Legg-Calv6-Perthes, Kohler, Chandler) Vasculitis (SLE,polyarteritis nodosa,rheumatoid arthritis) Environmental (frostbite, thermalinjury) lrradiation Neoplasia (-associated coagulopathy) Fat (prolonged corticosteroid increasesmarrow) use Alcoholism Renalfailure+ dialysis Caissondisease Trauma(femoralneck fracture,hip dislocation) Sicklecell disease NO predisposing factorsin 25/"1

Disorders 47

Location: femoralhead (mostcomm ), humeral head, femoralcondyles

Avascular Necrosis Hip of0 Involvement one hip increases to contralateral of hi pto 70/" 1 Age: 20-50 years . hip / groin/ thigh/ kneepain . limitedrangeof motion Plainfilm (positive only several s aftersymptoms): r/ subtle relative sclerosisof head secondary to resorption surrounding of v larized bone (earliest sign) { radiolucent crescentparallelto icularsurfacein portionsecon weight-bearing to subchondral structural collapseof necrotic portionof Site: anterosuperior head (best seen on froglegview) r/ preservation joint space (DDx arthritis) of r/ flattening articularsurface of ./ increased densityof femoralh (compression of bonytrabeculae following mi ure of nonviable bone,calcification of riticmarrow. = creeping substitution depositio of new bone) CI assif ication ( Steinberg): Stage0 = normal - normallbarely Stage | mottling; abnormal StagellA = focalsclerosis + StagellB = distinct sclerosis + + earlycrescent si S tagel l l A = subchondral u sign")+ cyst StagelllB = mildalteration in

trabecular

ne scan MRt iia eoporosts ning ("cresgenl n head

contour I+ normal j oi nt Stage lV = markedcollapseof + significant StageV = degenerative moral head + acetabular

NUC (80-85% sensitivity) : 0 Bonemarrowimaging (with loid)more sensitive (wi diphosphonates) than bone imaging 0 Moresensitive y AVN than plainfilmsin (evidence ischemiaseen as of as 1 year earlier) 0 Lesssensitive than MR Technique; imagingimprovedwi doublecounts, pi nhol e l i mati on col { early: cold = photopenic defect(i blood supply) ^/ late: "doughnut sign" = cold spot by increaseduptakesecondary to (a) capillaryrevascularization + synthesis (b) degenerative osteoarthritis CT (utilized staging knowndi for of r/ stagingupgradesin 30% with plainfilms

Radiology Review Manualmarrow DDx: bone marrowedema (ill-delimited epiphyseal changes,no reactiveinterface); areas, / fracture(speckled linearhypointense contour); of focal depression epiphyseal spondyloarthroPathY

85% specificfor symptomatic MR (90-100% sensitive, disease): occultdisease: 6% Prevalenceof clinically 0 MR imagingchangesreflectthe death of marrowfat with empty lacunae)! cells (not death of osteocytes useful! 0 Sagittalimagesparticularly CI assification (MitcheII) : T1 T2 intermediate high high low Analogous to fat blood subacute fluid/ edema fibrosis

BlountDisease= TIBIA VARA = oVsscular necrosisof medialtibialcondyle Age: >6 years . limping, lateral bowingof leg + enlarged deformed { medialtibialcondyle (DDx:Turnersyndrome) (medially posteriorly + of { irregularity metaphysis prolonged with beak)

A B

c

D

high high low low

EARLYAVN: on Gd-enhancement short-inversion{ decreased recovery(STIR)images(veryearly) r/ low-signal intensity band with sharp inner + outermarginon TlWl within interface blurred + 1248 hours (= Iilseflchymal fibrousrepair debris, thickened cellular tissue,amorphous bone)seen as trabecular bone plate (a) band extending subchondral to (b) completering (lessfrequent) r/ "double-line sign"on T2Wl (in 80%) [MORE = of SPECIFICI juxtaposition innerhyperintense tissue)+ outer hypointense band (granulation shift artifact/ fibrosis+ sclerosis) band (chemical AVN: ADVANCED edema pattern" { "pseudohomogeneous = inhomogeneous largeareasof mostly on signalintensity TlWl decreased lesionon T2WI { nypo-to hyperintense r/ contrast-enhancement interface surrounding + of marrow+ withinlesion FRACTURE: SUBCHONDRAL portionof femoral r/ predilection anterosuperior for images!) head (sagittal i/ cleft of low-signal intensityrunningparallelto the bone platewithinareasof fatlike subchondral on signalintensity Tl Wl ^/ hyperintense band (= fracturecleftfilledwith or articularfluid/ edema)withinthe intermediatenecroticmarrowon T2Wl low-signal-intensity r/ lack of enhancement within+ aroundfracture cleft EPIPHYSEAL COLLAPSE: r/ focal depression subchondral bone of Cx: throughcollapseof femoral earlyosteoarthritis in head + joint incongruity 3-5 years if left untreated (for (1) coredecompression grade0-ll): most involvement femoral of with 40 years; 10% in (rapi dl y fatal );M:F = 2:1 chi l dren . hyperglycemia paraneoplastic syndrome(85%) as Location: neckof femur,pubicrami,proximal bone, ribs (19%),skull(sphenoid humerus, sternum, angle,mandible), cerebellopontine spine(3-12%)

Disorders 57 Boneand Soft-TissueSite: central withinmedullary canal+ meta-/ diaphysis lesion1 to severalcm in size { expansile osteolytic r/ shorttransition zone + scleroticmargin(welldefined from host bone) punctate/ snowflake { t small irregular type of calcification; single/ multiple { late: loss of definition breakthroughcortex + { endosteal corticalthickening, sometimesat a distance from the tumor (due to invasionof haversian system) { presenceof largesoft-tissue mass DDx: benignenchondroma, osteochondroma, osteosarcoma,ibrosarcoma f r/ focal regionsof radiolucency interiorof lesion in r/ erosion/ destruction adjacentbone of Metastases: in 3-7oh,most commonlyto lung Rx: wide resection Prognosis; 70-90%long-termsurvival (denselycalcified DDx: (1) Osteochondroma with multiplepunctatecalcif ications) (2) Parosteal (morehomogeneous osteosarcoma densityof calcified osteoid)

ClearCellChondrosarcoma0 Usuallymistakenfor chondroblastoma becauseof low grademalignancy (maybe related)! Histo: small lobulesof tissuecomposedof cellswith filledvesicular nucleisurrounded by centrally largeclear cytoplasm Age: 19-68 years,predominantly after epiphyseal fusion proximal femur,proximal humerus, Location: proximal (5%);pubicramus ulna,laminavertebrae Site: epiphysis r/ singlelobulated oval / roundsharplymarginated lesionof 1-2 cm in size ./ surrounding increased bonedensity rapidgrowthover 3 cm r/ aggressive r/ may containcalcifications r/ bone often enlarged from r/ indistinguishable conventional chondrosarcoma / (slowgrowthover years) chondroblastoma

Peripheral Chondrosarcoma= EXOSTOTIC CHONDROSARCOMA = malignant degeneration hereditary of multiple osteochondromatosis rarelyof a solitary and (beginning cartilaginous of exostosis) exostosis in cap Frequency: 8o/"of all chondrosarcomas Averageage: 50-55 years for solitaryexostosis; 25-30 years for hereditary multiple o s te o c h o n d ro ma to sM:F = 1 .5:1 is; Histo: low histologicgrade in 67-85/" . growthafterskeletalmaturity . graduallyincreasing pain,oftenworse at night . localswellingi palpablemass (45%) Location: pelvis,hip,scapula, ribs,ends of sternum, humerus femur,skull,facialbones / { growthof a previously unchanged osteochondroma in maturepatient , a skeletally largesoft-tissue ! unusually mass 1=hyaline cartilage cap) containing flocculent streakychondroid / (CHARACTE ISTIC) ications calcif R : { cartilage cap 1.5-12 cm (average, 5.5-6 cm) thick 0 >1.5cm is suspect malignant of transformation ./ irregular indistinct / lesionsurface: r/ dense radiopaque centerwith streaksradiating to periphery with loss of smoothmargin

Extraskeletal Chondrosarcomalncidence: 2'/. of all soft-tissuesarcomas

Myxoid Extraskeletal Chondrosarcoma (most common)Mean age: 50 years (range 4-92 years); M > F

Enchondroma versusChondrosarcoma Appendicular in SkeletonEnchondromaMeanage and sex Palpablemass Pain Lesionlocation Site Lesionsize Endosteal scalloping relative corticalthickness to refative lesionlength to (radiography) Corticalremodeling (radiography) Corticalthickening Perisoteal reaction(radiography) Pathologic fracture(radiography) (CT) Matrixmineralization (CT) Corticaldestruction Soft-tissue extension(MR) Small hyperintense (T1Wl) foci 40 years;M:F = 2:3 28% 40% (tracture associated) hands,feet diaphysis 213of corticalthickness, 79o/"along>213 lesion of 47% 47% 47% 27% 94% (lessextensive) 88/o 76% 35%

Histo: surrounded fibrouscapsule+ dividedinto by lobules fibrous multiple by septa;delicate strandsof small elongated chondroblasts are in suspended an abundant myxoidmatrix; foci of maturehyalinecartilageare rare . slowlygrowingsoft-tissue mass . pain+ tenderness (33%) 0 Metastatic 40-45/o at time of presentation! in (thighmostcommon) Location: extremities Site: deep soft tissues;subcutis(25%) r/ lobulated soft-tissue mass WITHOUTcalcification / ossification r/ usuallybetween4 and 7 cm in diameter MR: r/ approximately equalto muscleon Tl Wl + equal to fat on T2Wl { may mimica cyst/ myxoma Prognosis: 45/" 1O-year survivalrate;5-15 years survivalafterdevelopment metastases of

ExtraskeletalMesenchymalChondrosarcoma0 50% of all mesenchymal chondrosarcomas arisein soft tissues Histo: proliferation small primitive mesenchymal of cellswith scatteredislandsof cartilage; hemangiopericytoma-like vascularpattern Bimodal age distribution: M = F (a) tumorsof head+ neck in 3rd decade(common): periorbital meninges, region (b) tumorsof thigh+ trunkin Sthdecade . frequently metastasized lungs+ lymphnodes to (50-100%) characterized { matrix mineralization as rings + arcs / flocculent stippledcalcification + i densemineralization MR: r/ approximately equalto muscleon Tl Wl + equal to fat on T2Wl r/ signalvoids from calcifications ^/ homogeneous enhancement Prognosis: 25o/"10-yearsurvival rate

@ Chest / r/ hypoplasia absence(10%)of clavicles(defective usuallyof lateralportion,R > L (DDx: development pseudarthrosis clavicle) of congenital ./ thorax may be narrowed+ bell-shaped ribs r/ supernumerary r/ incompletely ossified sternum (frequent) spondylosis r/ hemivertebrae, @ Pelvis ossification bonesformingsymphysis of { delayed pubis(DDx: bladder exstrophy) iliacbones ri hypoplastic @ Extremities r/ radiusshort/ absent secondmetacarpals { elongated ./ pseudoepiphyses metacarpal of bases distalphalanges hand of r/ short hypoplastic terminal tufts { pointed { conedepiphyses { coxa v?fzl= deformed/ absentfemoralnecks epiphysesin hands + feet (common) r/ accessory OB .U S : (largefetal head + narrow { cephalopelvic disproportion birthcanal of affectedmaternalpelvis)necessitates cesareansection

coccrDrorDoMYcosrsgranulomatous process bones,joints, in Histo: chronic periarticu structures lar in of Location: (a) bones: most frequently metaphyses longbones+ medialend of clavicle, spine, of ribs,pelvisi bony prominences patella, calcaneus, olecranon, tibialtuberosity, acromion joints(33%): ankle,knee, (b) weight-bearing

ytfi:i"lTeu

"= m matism im une-comptex-

CLEI DOCRANIAL DYSOSTOSIS = CLEIDOCRANIAL = MUTATIONAL DYSPLASIA DYSOSTOSIS = delayedossification midline (particularly of structures of membranous bone) Autosomal dominant disease @ S k ull . large head ^/ diminished absentossification skull(in early / of infancy) r/ wormianbones r/ widenedfontanels sutures with delayed + closure metopicsuture { persistent r/ brachycephaly prominent + bossing ./ largemandible ^/ frighnarrowpalate(t cleft) ^/ hypoplastic paranasal sinuses r/ delayed/ defective dentition

mediatedarthritis (c) tenosynovitis hand,bursitis of formationof cavities(early) r/ focal areasof destruction, = bubblybone lesion ./ bone sclerosis (later,rare) osteolysis surrounding of d proliferation overlyingperiosteum of { destruction vertebrawith preservation disk space of may from r/ psoasabscessindistinguishable tuberculosis, calcify from direct r/ loints rarelyinfected(usuallymonoarticular focus): synovial effusion, of extension osteomyelitic joint space narrowing, bone destruction, osteopenia, ankylosis common r/ soft-tissue abscesses DDx: tuberculosis CONGENITAL INSENSITIVITY TO PAIN WITH ANHYDROSIS = ra(aautosomalrecessive on disorderpresumably the neuralcrestdevelopment basisof abnormal Age: presenting birth at

Boneand Soft-Tissue Disorders 59Incidence; 15 reportedcases Path: absenceof dorsal+ sympathetic ganglia, deficiency neuralfibers1.5 mm r/ deepening lateral of { posterior displacement posteriorhorn of lateral of meniscus >3.5 mm behindtibialplateau { anteriortranslation tibia (= ?nteriordrawersign) of ^/ pCL bowing= lflgl betweenproximal+ distal lim bsof P C L < 1 0 5 o False-positive Dx: (1) slicethickness interslice too great gap / (2) adjacentfluid/ synovialproliferation (3) cruciateganglion/ synovialcyst Associated injuries: meniscaltear (lateral> medial)in 65%

DEEP FIBROMATOSES Fibromatosis Aggressive Infantile= childhood equivalent deep fibromatosis of Age: first 2 years of life; rarely>5 years of age; M > F fibrosarcoma Histo: may mimic infantile . firm nodularsoft-tissue mass withinskeletalmuscle/ fascia/ periosteum mastoid), mandible, Location: head,neck (tongue, shoulder, thigh,foot

Tumor Desmoid Extraabdominal= DEEP = AGGRESSIVE FIBROMATOSIS FIBROMATOSIS = MUSCULOAPONEUROTIC FIBROMATOSIS = corT]rTlor't growingsoft-tissue benignaggressively from connective tissueof muscle, tumorarising fascia,aponeurosis outsideabdominal cavity Peak age: 25-35 years

Chronic ACL Tear{ often completeabsenceof ligament

Boneand Soft-Tissue Disorders 61Histo: parallelhalo arraysof uniform-appearing fibroblasts surrounded highlyvariable by amountsof collagenfiberswith infiltrative growth pattern . painlesssoft-tissue mass Location: extremities (70%);shoulder(20/"), chest wall + back (15%),thigh (12%),mesentery (10%),neck (10%),knee (T%);solitary (majority) synchronous / multicentricity in same extremity(10-1 5%) 0 Most commonbenignsoft-tissue tumor of the foot Site: fasciain / aroundmuscle { mostly16

Classification: 1 . N o r m ah i p l hip 2. Lax = subluxable 0 subluxability to 6 mm is normalin newborns up (stillunderinfluence maternal hormones); of to decreasing 3 mm by 2nd day of life HIP DISLOCATABLE UNSTABLE 3. Concentric = joint laxityallowingnondisplaced femoralhead to becomesubluxedI dislocated understress lncidence: 0.25-0.85ohof all newborn infants (213are firstborns) . Barlowpositive i/ slightincreasein femoralanteversion in cartilage r/ mild marginalabnormalities acetabular { early labraleversion Prognosis: 60ohwill become stable after 1 week; 88% will becomestableby age of 2 months HIP SUBLUXED 4. Decentered = femoralheadshallowin location { loss of femoralhead sphericity ^/ increased femoralanteversion r1 early labralinversion { shallowacetabulum DISLOCATED HIP 5. Eccentric = femoralhead franklydisplaced of acetabulum out = (a) reducible Ortolanipositive = (b) irreducible Ortolaninegative flattening femoralhead of r/ accentuated r/ shallowacetabulum r/ limbusformation(= inwardgrowth+ hypertrophy of labrum) . "hipclick"= usually resultof jointcapsuleand tendon "hip clunk") + stretching snapping(oftenconfusedwith . positiveexamination result(up to 3 monthsof age): . positiveOrtolani reduction test = reduction of proximalfemur into the acetabulum progressive by with abductionof flexedhips and knees+ associated audible"clunk" . positiveBarlow dislocation test = displacement of proximalfemur by progressive with adduction on downwardpressure(pistonmaneuver) flexed hips with audible"clunk" and kneesassociated . warningsignson physical examination: . limitedhip abduction affectedside on . shortening thigh on affectedside: of . asymmetric thigh / buttockcreases . Allis sign = Galeazzi sign = affectedknee is lower with kneesbent in supineposition . Trendelenburg = visibledrooping shortening + test side with child standingon both feet, on dislocated then one foot =1 Location: left:right:bilateral 1:1:4 Radiologic lines: 1.Lineof Hilg e n re i n e r = line connecting marginsof triradiate superolateral cartilage

Perkin's line center-edge acetabularangle

Shenton's line

RadiographicLines of Hip Joint Position

angle/ index 2. Acetabular = slope of acetabular roof = ?rl9lethat lies between line Hilgenreiner's and a linedrawnfrom most to ossifiededge of acetabulum superolateral cartilage marginof triradiate superolateral l 3. P erki n' si ne = vertical line lineto Hilgenreiner's throughthe lateral rim of acetabulum curvedline 4. Shenton's pubic = dfc formedby inferior surfaceof superior foramen)+ medialsurface ramus(= top of obturator to of proximalfemoralmetaphysis levelof lesser trochanter of ri disruption line (DDx: coxavalga) angle 5. Center-edge = oflgle subtended one line drawnfrom the by edge to centerof femoralhead + second acetabular centersof to lineperpendicular lineconnecting femoralheads ./ 60o

B Angle55o

ct >60"bony acetabulum

50 - 59.

\43 - 49. 66Yo) morethan one area of = involvement a singleextremity in with characteristic hemimelic distribution: talus,distalfemur,distaltibia (3) Generalizedlsevere form = diseaseinvolving the whole lowerextremity r/ pelvicinvolvement: femoralhead,symphysis pubis,triradiate cartilage { hypertrophy ipsilateral of iliac bone . antalgic pain-avoiding) palpable (= gait; mass . varus/ valgusdeformity; limb lengthdiscrepancy . limited jointmobility and function Location:lowerextremity(tarsus,knee,ankle);rare in upperextremity (humerus, ulna,scapula) Site: restricted medialOR lateralside of limb to (= hemimelic), medial:lateral 2:1 = ie,

@ lnfant& toddler lobulated, of { prematureappearance an eccentric, center ossification asymmetric overgrown, r/ stippledcalcification anomalous cartilage of @ Childhood ./ disorganized accompanied calcification epiphyseal ossification by irregular growthfrom one side of { osteochondroma-like epiphysis r/ premature closureof physisresultsin limb deformity and limb lengthdiscrepancy articularsurfacecombinedwith angular r/ irregular deformity of of r/ undertubulation bone as a consequence of secondaryinvolvement metaphysis Cx: prematuresecondaryosteoarthritis DDx: osteochondroma

OF ECHINOCOCCUS BONEin in Occursoccasionally the USA;usually foreign-born in bone involvement 1% individuals; tissuebarrier;daughtercysts Histo: no connective extenddirectlyinto bone sacrum,rarelylongtubularbones @ Pelvis, regionsof rarefaction r/ round/ irregular r/ multiloculated lesion(bunchof grapes) giantcell ./ no sharpdemarcation (DDx:chondroma, infection: tumor)with secondary perifocal with generalized of r/ thickening trabeculae condensation r/ corticalbreakthrough mass with soft-tissue @ Vertebra r/ sclerosis fracture withoutpathologic ^/ intervertebral disks not affected { vertebrallaminaoften involved involvement adjacentribs of r/ frequently

radius, (hip,patella, shoulder, dislocations { recurrent clavicle) (predominantly knees) in osteoarthrosis r/ precocious ^/ ulnarsynostosis r/ kyphoscoliosis { spondylolisthesis ! spinabifidaocculta @ Chest hernia r/ diaphragmatic + emphysema bullaformation r/ panacinar + { tracheobronchomegalybronchiectasis Arteries @ r/ aneurysmof greatvessels,aorticdissection, arteries of tortuosity arch,ectasiaof pulmonary CONTRAINDICATED! O AORTOGRAPHY aorticrupture, (Cx followingarteriography: hematomas) @ Gl tract tract r/ ectasiaof gastrointestinal

ELASTOFIBROMAto = benigntumorlike lesionformingas a reaction friction mechanical of lncidence: in 24/" of women + 11o/o men >55 years (autopsystudY) A ge: el derl y;M:F = 1:2 serratedelastic Histo: enlargedirregular noph lic f ibers, collagen,scattered i hypereosi lobulesof adiposetissue occasional fibroblasts, . asymptomatic . may remainclinically inapparent Location: betweeninferiormarginof scapula+ posterior chestwall; bilateralin 25/" poorlydefinedlesionof soft-tissue { inhomogeneous to similar muscle attenuation lesionwith intensity r/ well-defined intermediate-signal signalon Tl Wl + T2Wl areas of fat-intensity interlaced

SYNDROME EHLERS-DANLOS= group of autosomal dominantdiseasesof connective by tissuecharacterized abnormalcollagensynthesis Types: 10 types have been describedthat differ and biochemically, genetically clinically, in Age: presentat birth; predominantly males . hyperelasticity skin of . fragilebrittle skinwith gapingwoundsand poor healing . molluscoid pseudotumors over pressurepoints . hyperextensibility joints of . joint contractures with advancedage . bleedingtendency(fragility bloodvessels) of . blue sclera,microcornea, ectopia myopia,keratoconus, lentis @ Soft tissues (2-10 mm) in subcutis / ovoidcalcifications { muftiple in most frequently in fatty cysts ("spheroids"), periarticular areas of legs r/ ectopicbone formation @ Skeleton i/ hemarthrosis (particularly knee) in of / / { malalignmentsubluxationdislocation jointson stress radiographs

ENCHONDROMAgrowthin medullary cavity;bones = benigncartilaginous preformedin cartilageare affected(NOT skull) lncidence: 3-17"/" of biopsiedprimarybone tumors 0 Secondmost commoncartilage-containing tumor! growthof residualbenignrestsof Etiotogy: continued displacedfrom the growthplate cartilage Age: 10-30 years; M:F = 1:1 Histo: lobulesof pure hyalinecartilage . usually painless swelling asymptomatic, = multiple erlchondromatosis) Location: (usuallysolitary; (a) in 40% smalltubularbonesof wrists+ tumorhere),distal+ hand (mostfrequent proximal/ mid aspectsof metacarpals, middlephalanges humerus, tibia, (b) proximal femur,proximal radius, ulna,foot,rib (3%) canal + metaphyseal; Site: centralwithinmedullary only affectedafterclosureof growthplate epiphysis with destruction r/ oval / roundarea of geographic line contour+ fine marginal lobulated

Boneand Soft-Tissue Disorders 71r/ corticalendosteal scalloping r/ ground-glass appearance r/ dystrophic calcifications withinsmallcartilage nodules / fragments lamellar of bone: pinhead, stippled, "ringsand flocculent, arcs" pattern r/ bulbousexpansion bone with thinningof cortexin of smalltubularbonesof phalanx, fibula rib, ./ Madelung = deformity bowingdeformities limb, of discrepant length { NO corticalbreakthrough periosteal / reaction MR: ^/ low-to intermediate-signal intensity Tl Wl + highon signalintensity T2Wl on r/ low-signal intensity matrixcalcifications r/ normalfat marrowinterspersed betweencartilage nodules i/ peripheral enhancement pattern Cx: (1) Pathologic fracture (2) Malignant degeneration long-bone in enchondromas 1S-20%(gradually in increasing pain in an adult patient) DDx: (1) Epidermoid inclusion cyst (phalangeal tuft, history trauma,more lucent) of (2) Unicameral bonecyst (rarein hands,more radiolucent) (3) Giantcelltumorof tendonsheath(commonly erodesbone,soft-tissue mass outsidebone) (4) Fibrousdysplasia(rarein hand, mostly polyostotic) (5) Bone infarct (6) Chondrosarcoma (exceedingly in rare phalanges, metacarpals, metatarsals) r/ associated with dwarfingof the involvedbone due to impairment epiphyseal of fusion r/ bowingdeformities limb bones of r/ discrepancy length= Madelung in (radius, deformity ul na) r/ small bones of feet + hands: aggressive deforming tumorsthat may breakthroughcortexsecondary to tendencyto continueto proliferate r/ fanlikeradiation cartilage of from centerto crest of ilium Cx: sarcomatous transformation 25-30%): (in (youngadults);chondro-/ osteosarcoma fibrosarcoma older patients) (in Maffuci Syndrome = nonhereditary mesodermal dysplasiacharacterized by enchondromatosismultiple + soft-tissue cavernous hemangiomas lesscommonly + lymphangiomas Age: 25/" during 1st year of lite; 45h prior to 6 years; 78/"betore puberty;M > F Association: juvenilegranulosacell tumor of ovary . multiple bluesubcutaneous particularly nodules on digits+ extremities (cavernous hemangiomas) . normalintelligence Location: unilateral involvement (50%)/ marked predilection tubular asymmetry; distinct for bonesof hands+ feet r/ phleboliths may be present { strikingtendencyfor enchondromata be very large to projecting into soft tissues { growthdisturbance long bones (common) of Cx: (a) malignant transformation of (1) Enchondroma chondrosarcoma to / (15-20%) fibrosarcoma (2) Cavernous hemangioma hemangioto sarcoma hemangioendothelioma / / lymphangiosarcoma 3-5%) (in (b) increased prevalence ovariancarcinoma, of pancreatic carcinoma, CNS glioma, gastrointestinal adenocarcinoma Prevalenceof malignancy: Zg-100% DDx: Ollierdisease(without hemangiomas)

ENCHONDROMATOSIS= OLLIER = DISEASE DYSCHONDROPLASIA = Mg111P1' ENCHONDROMATOSIS = nonhereditary failureof cartilageossification Cause: derangement cartilaginous of growthresulting in migration cartilaginous of restsfrom epiphyseal plate into metaphysis where they proliferate Age: early childhood presentation Association: juvenilegranulosa cell tumor of ovary . growthdisparity with leg I arm shortening . hand + feet deformity Location: predominantlyunilateral monomelic (a) distribution locatized regional (b) (c) generalized r/ well-demarcated rounded radiolucencies / columnar streaksof decreased densityfrom epiphyseal plate into of rests , diaphysis longbones= cartilaginous ! expansileremodeling affectedbone: of r/ clublikedeformity expansionof metaphyseal / region preOominant thinning cortex+ endosteal of scalloping ! ./ bony spurs pointing ioward the joint (DDx: exostosis pointsaway from it) r/ cartilaginous areasshow punctate calcifications with age: r/ matrixmineralization Typ|CAL arc-and-ring with appearance chondroid of lesions

ENGELMANN.CAMURATI DISEASE

= PROGRESSIVE = CAMURATIDIAPHYSEAL DYSPLASIA ENGELMANN DISEASE Cause: autosomal dominant; disturbance in intramembranous boneformation modeling + (as occursin cortexof long bones,calvaria, mandible, facialbones,midsegment clavicle) of Age: 5-25 years (primarily childhood);M > F in ' neuromuscular dystrophy= delayedwalking(18-24 months)with wide-based waddlinggait; often misdiagnosed musculardystrophy/ poliomyelitis as . weakness+ easy fatigability legs in . bonepain+ tenderness usually midshaft longbones in of . underdevelopment muscles of secondary malnutrition to . NORMALlaboratory values Location: usually symmetrical; involvement NO of hands,feet,ribs,scapulae

affected) @ Skull(initially r/ amorphousincreasein densityat base of skull sinus;sparingof of r/ encroachment frontal+ sphenoid maxillary sinus distribution) symmetrical @ Longbones(bilateral > Site: tibia> femur> fibula> humerus ulna > radius r/ fusiformenlargement diaphyses with cortical of of (endosteal periosteal accretion + thickening of obliteration mottlednew bone)and progressive cavity medullary of r/ progression lesionsalong long axis of bone towardeitherend + of r/ abruptdemarcation lesions(metaphyses spared) epiphyses r/ relativeelongation extremities of (single bone) osteomyelitis DDx: (1) Chronic (high (2) Hyperphosphatasemia alkaline phosphatase levels) (3) Pagetdisease(age,new-boneformation, alkalinephosphatase) increased (fever;mandible, (4) Infantile corticalhyperostosis whit e 13,for gi rl s11 years); with: Associated developmental abnormality, (a) malnutrition, endocrine adolescence) of dysplasia hip (during (afteradolescence) (b) delayedskeletalmaturation . hip pain (50%)/ knee pain (25'h) for 2-3 weeks in bilateral 20-37"/"(at initial Location: usuallyunilateral; presentation 9-18%) in phase): growthplate(preslip of { widening epiphyseal physis of + { irregularity blurring physeal r/ demineralization neckmetaphysis of of displacement head (acuteslip): { posteromedial change anglewith alignment in { decrease neck-shaft in the growthplateto a more verticalorientation edgeof r/ lineof Klein(= linedrawnalongsuperior the femoralneck)failsto intersect femoralhead slippage: r/ epiphysis smaller due to posterior appears LAT view early slips are best seen on cross-table view may cause into CAVE: positioning a frogleg furtherdisplacement slip): of + { sclerosis irregularity widenedphysis(chronic opacity blanchsign = area of increased r/ metaphyseal (healingresponse) in proximalpart of metaphysis Grading (based on femoral head position): = displaced 213of metaphyseal

Inclusion Cyst Epidermoid= = INTRAOSSEOUS CYST KERATIN CYST IMPLANTATION Age: 2nd-4th decade; M > F keratin, squamousepithelium, Histo: stratified crystals(softwhite cheesycontents) cholesterol . history trauma(implantation epithelium under of of skin with secondarybone erosion) . asymptomatic situatedbonessuch as Location: superficially in calvarium(typically frontal/ parietal tuft terminal of bone),phalanx(usually in middlefinger), > R hand,occasionally L foot with scleroticmargin roundosteolysis r/ well-defined expanded+ thinned { cortexfrequently reaction/ soft-tissue / { NO calcifications periosteal swelling reaction fractureoftenwithoutperiosteal r/ pathologic

Line of Klein in Normal Hip

Boneand Soft-Tissue Disorders 73Cx: (1) Chondrolysis ocute cartilagenecrosis(7-10%) = = rapid loss of >50y" of thicknessof cartilage r/ joint space age 10; i n 30% < age 1 0) 0 >20 years of age predominantly flat bones in 0 50 yearsof age is most likelyMFH! (75/"), flowerextremity Location: extremities (50%),upperextremity(25%)1, (15/"), head + neck (5%) retroperitoneum Site: withinlargemusclegroups . large painlesssoft-tissue mass with progressive enlargement overseveralmonths over 5-10 cm in sizewith increase { mass usually months/ years peripheral / { poorlydefinedcurvilinear punctate (in / calcifications ossifications 5-20%) bone (HIGHLY of erosion adjacent r/ cortical F S UG G E ST IV E E AT U R E ) CT: mass with central r/ well-defined soft-tissue MFH (DDx: hypodense area = rnyxoid leiomyosarcoma with hemorrhage, necrosis, necrosis, myxoidlipo-/ chondrosarcoma) enhancement solidcomponents of MR: poorlydefinedlesioniso-/ inhomogeneous hyperintense muscleon Tl Wl + hyperintense to on T2Wl Prognosis: larger+ more deeplylocated tumors have a worse prognosis; 2-year s urvivalrate of 60'/"; S-year survivalrate of 50%; local recurrencerate of 44o/"; rate of 42h (lung,lymph nodes,liver, metastatic bone) (youngerpatient,presenceof DDx: (1) Liposarcoma rare) fatin >40/", calcifications (2) Rhabdomyosarcoma (3) Synovialsarcoma(cortical erosion)

Osseous MFHbone tumors Prevalence: 5/." of all primarymalignant . painful, mass enlarging tender,rapidly . pathologic fracture(20%) Associated with: prior radiation therapy,bone infarcts,Paget osteonecrosis, disease,fibrousdysplasia, (= fibroma), fibroxanthoma nonossifying osteomyelitis chronic enchondroma, 0 20% of all osseousMFH arise in areas of abnormal bone! Location: femur (45/"), tibia (20%),50/" about (10% ); l i um(1 0%) ; spine; i knee;humerus rarelysmallbonesof clavicle; sternum; hand + feet of Site: centralmetaphysis long bones (90%); of in eccentric diaphysis longbones(10%) r/ radiolucent margins(2.5-10 defectwith ill-defined cm in diameter) r/ extensivemineralization small areasof focal / ication metaplastic calcif + r/ permeation corticaldestruction fibula, bones(ribs,sternum, in r/ expansion smaller clavicle) ./ occasionallylamellatedperiostealreaction fracture) (especially presenceof pathologic in r/ soft-tissue extension fracture(30-50%) Cx: pathologic DDx: (1) Metastasis (oftenwith sequestrum) (2) Fibrosarcoma (3) Reticulum sarcoma cell (4) Osteosarcoma (5) Giantcelltumor (6) Plasmacytoma Pulmonary MFH (extremely rare) pulmonary calcification nodulewithout { solitary r/ diffuseinfiltrate NUC: ./ increaseduptakeof Tc-99mMDP (mechanism not understood) uptakeof Ga-67citrate ri increased US: + mass with hyperechoic hypoechoic r/ well-defined (necrotic) areas CT: ./ mass of muscledensitywith hypodense areas (necrosis) ^/ invasion abdominal musculature, not IVC/ but of renalveins(DDxto renalcell carcinoma) A ngi o: + r/ hypervascularity earlyvenousreturn FOCAL FIBROCARTILAGINOUS DYSPLASIA OF TIB IA Associatedwith: tibia vara Age: 9-28 months fibrous tissueresembling Histo: densehypocellular tendonwith lacunaformation

Boneand Soft-Tissue Disorders 79. slightshortening affectedleg of Location: insertion pes anserinus tendinous (= of insertion gracilis, of sartorius, semitendinosus muscles) distalto proximal tibialphysis; unilateral involvement r/ unilateral tibia vara r/ well-defined elliptic obliquely oriented lucentdefectin medialtibial metadiaphyseal cortex r/ sclerosisalong lateralborderof lesion r/ absence bone marginsuperomedially of Prognosis.' resolutionin 1-4 years DDx: (1) Unilateral Blountdisease(typically bilateral in infants,varusangulation uppertibia, of decreased heightof medialtibialmetaphysis, physis) irregular (2) Chondromyxoid fibroma, eosinophilic granuloma, osteoidosteoma, osteoma, fibroma, chondroma(not associated with tibiavara, softtissuemass) LENGTH = longitudinal changeof fragments = distraction increase from original anatomic length = shortening decreasefrom originalanatomiclength - impacted = fragments driveninto each other - overriding = alsoincludes latitudinal changes - overlapping bayonetapposition = D IS P LA C E ME N T = latitudinal changeof anatomic axis: - undisplaced - anterior, posterior, mediallulnar,lateral radial / A N GU LA TIONTILT / = longaxes of fragments intersect the fracture at apex: - medi al /l ateralventral /dorsal , - varus = dt']gular deviationof distalfragment toward midlineon frontalprojection - valgus = angular deviation distalfragment of away from midlineon frontalprojection eg, "ventralangulation fractureapex" of eg, "in anatomic nearanatomic I alignment" ROTATION 0 Difficult detectradiographically! to r/ differences diametersof apposingfragments in r/ mismatchof fractureline geometry - internal/external rotation NUC: Typicaltime course: 1. Acute phase (3-4 weeks) abnormal 80% 15odecreases grip strength+ endurancein >50%

Essex-LoprestiFracture(1918-1951), at surgeon Essex-Lopresti Gordon [Peter Englandl Accident Center, Birmingham ./ comminuted displacedradialhead fracture joint of r/ dislocation distalradioulnar

GaleazziFracturein (1866-1952), surgeon ltaly] orthopedic Galeazzi [Ricardo = PIEDMONT FRACTURE Mechanism: lall on outstretchedhand with elbow flexed { radialshaft fracture(mostcommonly)at junctionof distalto middlethird with dorsalangulation joint of / r/ subluxation dislocation distalradioulnar (= of { ulnarplusvariance radialshortening) >10 mm of disruption interosseous implies complete joint = of instability radioulnar membrane complete delayedunion, of Cx: (1) Highincidence nonunion, (unstable fracture) malunion (2) Limitation pronation supination / of

Chauffeur Fracture= = = HUTCHINSON FRACTURE FRACTUREBACKFIRE FRACTURE LORRY DRIVER (1828-1913), British surgeon] Hutchinson [Jonathan = n?rTl derivedfrom directtraumato radialside of from recoilof crank used in era of wrist sustained hand crankingto start automobiles of + Mechanism;acutedorsiflexion abduction hand ^/ triangular fractureof radialstyloidprocess

CollesFracturelreland] (1773-1843), in surgeon Dublin, Colles [Abraham = POUTEAU (term FRACTURE usedin France) (1725-1775), France] in Pouteau surgeon Lyon, [Claude 0 Most commonfractureof forearml Mechanism: tall on outstretchedhand r/ nonarticular radialfracturein distal2 cm ./ dorsaldisplacement distalfragment+ volar of angulation fractureapex of { + ulnarstyloidfracture deformity { "silver-fork" arthritis Cx: posttraumatic Rx: anatomicreductionimportant

Monteggia-typeFracture= fractureof ulnarshaft + dislocation radialhead of Bado Classification: from surgeon orthopedic LuisBado(1903-1977), [Jose Uruguayl Type | = classic Monteggia fracture (1762-181 ltalian 5), Monteggia Battista [Giovanni surgeonl Mechanism: direct blow to the forearm proximal ulnarfracture angulated { anteriorly of r/ anteriordislocation radialhead wrist injury r/ may have associated of limitation motionat elbow, Cx: nonunion, nerveabnormalities fracture Type ll = IeveISeMonteggia posteriorly / r/ radiathead displaced posterolaterally { dorsallyangulatedproximalulnarfracture Type l l l of dislocation radial r/ anterior/ anterolateral head fracture { ulnar metaphyseal Type lV of { anteriordisplacement radialhead r/ fractureof proximalthird of radius+ ulna at the same level

Colles Fracture

\1I

s\l@

I UJ

Barton Fracture

ChauffeurFracture

YlrT

Smith Fracture= = REVERSE BARTON COLLESFRACTURE REVERSE (termused in = FRACTURE GOYRANDFRACTURE France) Collesas succeeding [RobertWilliamSmith(1807-1873), professor surgeryat TrinityCollegein Dublin,lrelandl of

Boneand Soft-Tissue Disorders 85

qBadoTypeIII BadoTypeIV

BadoTypeI

Monteggia-type Fractures

BadoTypeII

Essex-Lopresti Fracture

GaleazziFracture

Mechanism; hyperflexion with fall on back of hand r/ nonarticular distalradialfracture r/ ventraldisplacement fragment of ! radialdeviation hand of { "gardenspade"deformity Cx: alteredfunctionof carpus

ElbowFracturecommonamongchildren2-14 years of age @ Soft-tissue r/ displacement anterior+ posterior pads of fat (= elbowjoint effusionwith supracondylar /lateral condylar/ proximalulnarfractures) r/ supinator pad (= fractureof proximalradius) fat r/ focal edema medially(= medialepicondyle / fx) laterally(= lateralcondylefx) (80%) @ Humerus Supracondylar fracture (55%) Mechanism; hyperextension with verticalstress r/ transverse fractureline r/ distalfragmentposteriorly displaced tilted / r/ anteriorhumeralline intersecting anteriorto posterior (on third of capitellum lateralx-ray) Lateral condylar fracture (20%) Mechanism; hyperextension varus stress with r/ fractureline betweenlateralcondyle+ trochlea/ throughcapitellum

Medial epicondylar fracture (5%) Mechanism: hyperextension with valgus stress (by { avulsionof medialepicondyle flexor muscles of forearm) r/ may becometrappedin joint space (after reduction concomitant of elbowdislocation) Radius(10%) @ Mechanism; hyperextension valgusstress with r/ Salter-Harris type ll / lV fracture metaphyseal radialneckfracture r/ transverse / Mechanism: hyperextension with varus stress r/ dislocation part of Monteggia fracture(from as rupture annularligament) of

supinator fat pad

posterior fat pad

| i r

"teardrop"

configuration formed bv coronoid and olecranon fossa

Anterior Humeral Line and Elbow Fat Pads

@ U l n a( 1 0 % ) linearfracture throughproximal shaft r/ longitudinal with verticalstress Mechanism; hyperextension fracturethrougholecranon r/ transverse Mechanism; hyperextension with valgus/ varus elbow in stress;blow to posterior flexedposition r/ coronoidprocessavulsion Mechanism; hyperextension-rotation associated m. with forcefulcontraction brachial of

Classification(Judet and Letournel): fractures A. Elementary wall 27% Anterior column 5% Posterior column 4o/" Transverse 9% Posterior wall 2% Anterior fractures B. Associated 27"/. wall Transverse posterior + 19% Bothcolumns 6% T-shaped Anteriorwall + posteriorhemitransverse 5% wall 3% Posterior column+ posterior PosrenronwALL(lle / nlu) rnncrvae (27%) through Mechanism: indirectforce transmitted lengthof femurwith flexedhipjoint (kneestrikesdashboard) dislocation femur of Associatedwith: posterior (9%) FRAcrune TRarusvensE + to N.B.: mostdifficult diagnose comprehend ./ transects + columns boththe iliopubic ilioischial direction with fractureline in an anteroposterior rnacrune (5%) Arurenron coLUMN with hip Mechanism; blow to greatertrochanter rotated externally column/ transverse Associatedwith: posterior fracture r/ fracturebeginsbetweenanterioriliacspines fossa + ends in the + traversesthe acetabular ramus ischiopubic rnncrunr (4%) PosrenroncoLUMN through Mechanism: indirectforcetransmitted lengthof femurwith hip abducted dislocation femur of Associatedwith: posterior + sciaticnerve injury r/ fracturebeginsat greatersciaticnotch aspectof acetabular + traversesthe posterior ramus fossa+ ends in the ischiopubic AHreRroR wALLrnacrune (2%) throughgreater Mechanism: force transmitted trochanter dislocation femur of Associatedwith: posterior + sciaticnerveinjury rim { fracture beginson anterior of acetabulum + emergeson lateralaspectof superiorpubic ramus

Rib Fracturelung Associatedwith: pneumothorax, hemothorax, / contusion laceration @ 1 s tr i b 0 Indicates substantial trauma (due to protected location) Cause: acutetrauma/ fatiguefracture(from carryinga heavyback pack) Associatedwith: aortic/ greatvesselinjury; thoracicvertebralfracture ; scapularfracture @ Lower ribs Associatedwith: injuryto upperabdominal organs / diaphragm

Flail Chest = fractureol >4 contiguous ribs . paradoxicmotionof chestwall with respiration . respiratory failure

Cough Fractureline Location: 4-gth rib in anterior axillary

PelvicFractureUnstablepelvicfractures (a) anterior compression pubicramifractures 1. Bilateral vertical jointdiastasis 2. Symphysis sacroiliac + (b) lateralcompression (ipsilateral 1. Malgaigne + fx) anterior posterior (contralateral 2. Bucket-handle anterior + posterior fx) (c) verticalshear 1. Superior displacement pelvis of

Acetabular Fracture Anatomy Function: &portionof acetabulum roof/ dome; is most important weight-bearing for surface entirelowerlimbis whichare derived+ supported 2 columns by orientedin an inverted"Y" and join abovethe acetabular roof at an angleof 60o: (a) anterior iliopubic columnof acetabulum (b) posterior ilioischial columnof acetabulum

Malgaigne Fracture(1806-1865), French surgical Malgaigne Francois [Joseph published comprehensive on fractures] book first historian, = fracture-dislocation one side of the pelviswith of of disruption pelvicring + anterior posterior Mechanism:directtrauma . shortening involvedextremity of throughone side of pelvicring r/ verticalfractures (ilium) (1) superior acetabulum to

Boneand Soft-Tissue Disorders 87

Transverse Fracture

Anterior Column Fracture

Posterior Column Fracture

Anterior Wall Fracture

Fracture of Both Columns

T-shaped Fracture

Anterior Wall + Posterior Hemitransverse Fracture

Posterior Wall + Posterior Column Fracture

Fracturesof the Acetabulum

e-z

-9:[!-g

-------= 1

F

Malgaigne Fracture

DuverneyFracture

(2) inferior acetabulum (pubicrami) to (3) + sacroiliac dislocation fracture / fragmentcontainsacetabulum r/ lateralunstable

Bucket Handle Fracturer/ doubleverticalfracturethroughsuperiorand inferior jointdislocation pubicrami+ sacroiliac on contralateral side

0 Lateralplateaufractures(type l-lll) are most common! with 0 Fractures medialplateauare associated of greater violence of and higherpercentage injuries! associated

Foot Fracture Ankle Fracturelncidence; ankle injuriesaccountfor 10% of all emergencyroom visits;85% of all ankle ligaments sprainsinvolvelateral at Ligamentous connections ankle: (a) binding tibia+ fibula ligament tibiofibular 1. anterior inferior (= tibiofibular syndesmosis) ligament inferiortibiofibular 2. posterior ligament tibiofibular 3. transverse membrane 4. interosseous (b) lateralmalleolus involve theseligaments: 85%of all anklesprains ligament 1. anterior talofibular ligament 2. posterior talofibular ligament 3. calcaneofibular = (c) medialmalleolus deltoidligament with portion 1. navicular portion 2. sustentaculum 3. talarportion Larenal Malleoun Fnacrunes Weber Type A (1929-), orthopedic Weber surgeon Georg [Bernhard in St.Gall, Switzerlandl = SUPINATION-ADDUCTION = INVERSIONINJURY A D D U C TION JU R Y IN

DuverneyFracture(1648-1730), French Guichard Duverney surgeon] [Joseph r/ isolatedfractureof iliacwing

KneeFracture SegondFracture(1851-1912), Ferdinand in at Segond surgeon chief [Paul in Francel SalpOtridreParis, Mechanism;externalrotation+ varus stresscausing tensionon the lateral excessive ligament capsular Associatedwith: lesionof anteriorcruciateligament (75-100V"), meniscaltear (67%) . anterolateral instability the knee of r/ smallcorticalavulsionfractureof proximallateral tibial rim just distalto lateralplateau Tibial Plateau Fracture (Schatzker classification) Mechanism.' valgusforce ("bumper fenderfracture" / from lateralforce of automobile against fixedknee)/ compression a pedestrian's force often in extension pure cleavagefracture 6% TypeI = wedge-shaped Typell = combinedcleavage+ median 25% fracture compression Typelll = pure compression fracture 36% TypelV = medialplateaufracturewith a split/ 10% depressed comminution TypeV = bicondylar fracture,oftenwith 3% invertedY appearance Type Vl = transverse obliquefracturewith 20"/" / from separation metaphysis of diaphysis

TypeI

(o) I 5\ Pellegrini-Stieda Disease

ffiTypeII

Type III

\ /l/

(

\

Type IV

ilryTypeV

TypeVI

Segond Fracture

Tibial Plateau Fractures

Disorders 89 Boneand Soft-Tissue

SupinationAdduction

SupinationAbduction

PronationExternal Rotation

LeFort Ankle Fracture

Tillaux Fracture

Mechanism: (1) avulsive forcesaffectlateralanklestructures (2) impactive forcessecondary talar shift to stressmedialstructures r/ spraini ruptureof lateralcollateral ligament 0 Anterior tibiofibular ligament ruptures alone in 66/" 0 Injuryof all 3 lateralligamentsin 20"/" Prognosis.'chroniclateralankle instability in 10-2oo/o { transverse avulsionof malleolus sparing ibularligaments tibiof r/ + oblique fracture medialmalleolus of r/ t posterior tibiallip fracture Weber Type B = SUPINATION-ABDUCTION = EVERSION. INJURY EXTERNAL ROTATION Mechanism: (1) avulsiveforceson medialstructures (2) impacting (talar forceson lateralstructures impact) r/ oblique spiralfracture lateral / of malleolus startingat levelof joint space extending proximally r/ lateralsubluxation talus of r/ partial disruption tibiofibular ligament of * tpt"in / rupture/ avulsionof deltoidligament I r/ + transverse fractureof medialmalleolus (a) Dupuytren Fracture Dupuytren (1777-1835), French surgeon] [Guillaume r/ fractureof distalfibulaabove a disrupted tibiofibular ligament disruption deltoid + of ligament (b) Le Fort Fracture of Ankle Clement Fort(1829-1893), Le French surgeon] [Leon r/ verticalfractureof anteriormedialportionof distalfibula r/ avulsion anterior of ligament tibiofibular Weber Type C = PRONATION-EXTERNAL = ROTATIONEVERSION + EXTERNAL ROTATION r/ fibularfracture higherthan anklejoint (Maisonneuve fracture aroundknee) if ./ + deltoidligament tear r/ + medialmalleolar fracture

ligament avulsionof r/ tear of tibiofibular / anteriortubercle(Tillaux-Chaput)avulsionof i posterior tubercle(Volkmann) r/ tear of interosseous membrane= lateral instability (a) Tillaux Fracture (1834-1904), Tillaux French Jules surgeon and [Paul anatomistl injuryof anterior at { avulsion tibialtubercle of attachment distalanteriortibiofibular ligament (b) Maisonneuve Fracture (1809-1897), Maisonneuve Gilles student [Jacques of Dupuytrenl r/ tear of distaltibiofibular syndesmosis membrane + interosseous { spiralfractureof upperthird of fibula fractureof medialmalleolus / r/ associated rupture deep deltoidligament of

Chopart Fracture(1743-1795), France] Chopart in surgeon Paris, [Francois ! fracture-dislocation throughmidtarsal Chopart / joint (calcaneocuboidtalonavicular) + with fracturesof the bones ! commonlyassociated abuttingthe joint

Maisonneuve Fracture

CalcanealFracturelncidence;most commonlyfractured tarsalbone; 2o/o 60% of all tarsalfractures; of all fracturesin the body;commonly bilateral fall from heights Mechanism: lumbarvertebralfracture May be associatedwith: A ge: 95% i n adul ts, i n chi l dren 5/" - adulthood: intraarticular (75'/.), extraarticular(25%) - childhood: extraarticular (63-92%) Classification: (a) extraarticular fractureof calcaneal tuberosity: horizontal, medialavulsion beaktype,vertical, (b) intraarticular fracture - subtalar jointinvolvement: undisplaced, displaced, comminuted - calcaneocuboid involvement joint ^/ apex of lateraltalar processdoes not pointto "crucial angle"of Gissane r/ Boehlerangle decreasedbelow 28o4}o

Lisfranc Fracture-Dislocation

Shepherd Fracture

Jones Fracture(1857-1933), British Jones orthopedic and surgeon [Robert pioneer radiologyl in fractureat base of Sth metatarsal r/ transverse distal to metatarsal >1.5cm from proximal tuberosity tip

PeroneusBrevis Avulsion Fracture= METATARSAL FRACTURE 5 TUBEROSITY Mechanism: plantarflexion+ inversion (stepping off a curb) ./ transverse avulsionfractureof base of 5th proximalto metatarsal metatarsal tuberosity (insertion peroneus of brevistendon) DDx: Jones fracture(slightly differentlocation)

FROSTBITEfrom freezing injury+ necrosis Cause: (1) cellular process (2) cessation circulation secondary cellular to of aggregates thrombiformingas a resultof + exposureto low temperatures below -13" C (usually cold air) . firm whitenumbareasin cutis(separation epidermalof dermalinterface) Location: feet,hands(thumbcommonly spareddue to protection clenchedfist) by Earlychanges: swelling+ loss of tissueat tips of digits { soft-tissue CHILD fusioni destruction distal of / { fragmentationpremature phalangeal epiphyses joint infection, cartilage injury, articular { secondary osteophytosis DIP of sclerosis, spacenarrowing, + of i { shortening deviation deformity fingers A D U LT (4-10 weeks after injury) { osteoporosis r/ periostitis ./ acromutilation (secondary osteomyelitis surgical + to (resultof soft-tissue loss) removal)+ tuftal resorption r/ smallroundpunched-out areasnearedge of joint joint ^/ interphalangeal abnormalities (simulating osteoarthritis) / of { calcificationossification pinna A ngi o: ^/ vasospasm, stenosis, occlusion (in of { proliferation arterial+ venouscollaterals recoveryphase) Bonescintigraphy: absenceof uptake(= lack of vascular { persistent perfusion) indicatesnonviable tissue reserpine with intraarterial Rx: selectiveangiography

Lisfranc Fracture(1790-1847), Lisfranc Saint De Martin in surgeon [Jacques Napoleon's army] Mechanism: metatarsal headsfixed and hindfoot forced plantanirrard into rotation and r/ fracture-dislocation / fracture-subluxation of joints (typically through5) tarsometatarsal 2 r/ lateraldisplacement metatarsals of

Shepherd Fracture(1851-1929), J. in demonstrator anatomy [Francis Shepherd at McGillUniversity Montreal, in Canadal r/ fracture of lateral tubercle of posterior process of

talus DDx: os trigonum

Peroneus Brevis Avulsion Fracture

JonesFracture

Boneand Soft-Iissue Disorders 91 GANGLIONclst = mucin-containing arising Ganglion from tendon cyst sheath/ joint capsuleI bursaI subchondral bone linedby flatspindleshapedcells cyst = cystcontinuous Synovial withjointcapsulelined by synovialcells (termis used by some synonymously ganglion) with ./ NO intraosseous (endosteal component surfaceintact) CT: soft-tissue mass adjacentto bone r/ well-defined cortexwith fluid contents MR: isointense signalto muscleon Tl Wl r/ homogeneous ^/ homogeneous hyperintense signaltofat on T2Wl ganglion) (DDx to soft-tissue r/ tttOinternalseptations withoutmatrixcalcification, DDx: periosteal chondroma subperiosteal aneurysmal bone cortical desmoid, hematoma(historyof cyst, acutesubperiosteal trauma/ blooddyscrasia), subperiosteal abscess (involvement adjacentbone marrow) of possibte) Rx: surgicalexcision(localrecurrence

Soft-tissue Ganglion= cystictumorlikelesionusuallyattachedto a tendon sheath Origin: synovialherniation coalescence smaller / of cystsformedby myxomatous degeneration of periarticular connective tissue . asymptomatic pain / . uni-/ multilocular swelling Loc