Skeletal Trauma- Plain filmSkeletal Trauma- Plain filmTrauma Terminology ReviewTrauma Terminology Review•• Dislocation = Complete loss of juxtaposition of normally Dislocation = Complete loss of juxtaposition of normally complementary articular surfacescomplementary articular surfaces

•• Subluxation = Partial loss of juxtaposition of normally Subluxation = Partial loss of juxtaposition of normally complementary articular surfacescomplementary articular surfaces

•• Diastasis = Separation of opposing surfaces at a symphysis, Diastasis = Separation of opposing surfaces at a symphysis, syndesmosis, suture or other minimally moveable articulationsyndesmosis, suture or other minimally moveable articulation

•• Compound fracture = fracture with protrusion of bone through Compound fracture = fracture with protrusion of bone through skin; “open” fracture.skin; “open” fracture.

•• Closed fracture = bone fractured, but not protruding thru skin.Closed fracture = bone fractured, but not protruding thru skin.

Trauma Terminology ReviewTrauma Terminology Review•• Occult fracture = fracture not immediately apparent on plain filmOccult fracture = fracture not immediately apparent on plain film x-rayx-ray

•• Complete fracture = fracture line completely thru the diameter Complete fracture = fracture line completely thru the diameter of boneof bone

•• Comminuted fracture = more than two pieces of bone resultComminuted fracture = more than two pieces of bone result

•• Avulsion fracture = Piece of bone pulled free due to traction on Avulsion fracture = Piece of bone pulled free due to traction on musculotendious or ligamentous insertion.musculotendious or ligamentous insertion.

•• Incomplete fracture = fracture does not extend completely Incomplete fracture = fracture does not extend completely through diameter of bonethrough diameter of bone–– Torus fracture/buckle fractureTorus fracture/buckle fracture–– Greenstick fractureGreenstick fracture–– Plastic deformity of bonePlastic deformity of bone

Trauma Terminology ReviewTrauma Terminology Review•• Pathologic fracture = fracture of bone due to weakening caused Pathologic fracture = fracture of bone due to weakening caused by underlying pathologic process (benign or malignant)by underlying pathologic process (benign or malignant)

•• Stress/fatigue fracture = application of repetitive stress to bone Stress/fatigue fracture = application of repetitive stress to bone results in microfratures of the trabeculae which eventually exceed to results in microfratures of the trabeculae which eventually exceed to body’s ability to repair. body’s ability to repair. NotNot result of an acute injury. result of an acute injury.

Fx DescriptionFx Description•• 1. Open vs. Closed1. Open vs. Closed

•• 2. Complete or Incomplete2. Complete or Incomplete

–– CompleteComplete

•• Comminuted Comminuted

•• Non-comminuted (Simple)Non-comminuted (Simple)

•• 3. Direction & Position3. Direction & Position

•• 4. Alignment4. Alignment

•• 5. Apposition5. Apposition

•• 6. Rotation6. Rotation

Fracture description/evaluationFracture description/evaluation•• Anatomic site and extent of fractureAnatomic site and extent of fracture

–– Diaphysis, metaphysis, articular involvement, etc.Diaphysis, metaphysis, articular involvement, etc.

•• Type of fractureType of fracture

–– Complete vs incompleteComplete vs incomplete–– Open vs closedOpen vs closed–– Simple vs comminutedSimple vs comminuted

•• AlignmentAlignment

–– Displacement, angulation, rotation or distractionDisplacement, angulation, rotation or distraction–– Always describe position of distal part relative to proximal partAlways describe position of distal part relative to proximal part–– Use clear reference (“apex of angle is medial or lateral”, or use Use clear reference (“apex of angle is medial or lateral”, or use varus/valgus descriptorvarus/valgus descriptor

Trauma Terminology ReviewTrauma Terminology Review•• Alignment = position of the distal fragment relative to the Alignment = position of the distal fragment relative to the proximal one; usually refers to the presence/absence of angulation.proximal one; usually refers to the presence/absence of angulation.–– In the spine, always describe the position of the superior In the spine, always describe the position of the superior vertebra of the involved motion segment relative to the one below.vertebra of the involved motion segment relative to the one below.

•• Apposition = describes the position of the fractured surfaces one Apposition = describes the position of the fractured surfaces one to another. Often described as the percentage of contact between to another. Often described as the percentage of contact between surfaces, (100% = complete contact) surfaces, (100% = complete contact)

Fracture description/evaluationFracture description/evaluation•• Direction of fracture (relative to long axis of bone)Direction of fracture (relative to long axis of bone)

–– Oblique, spiral, transverse/horizontal, longitudinalOblique, spiral, transverse/horizontal, longitudinal

•• Special features of fractureSpecial features of fracture

–– Compression, impaction, depression, etcCompression, impaction, depression, etc

•• Associated abnormalitiesAssociated abnormalities

–– DislocationDislocation–– Diastasis Diastasis

•• Special type of fractureSpecial type of fracture

–– StressStress–– pathologicpathologic

Fracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture description/evaluationFracture healing- vascular supplyFracture healing- vascular supply•• Medullary arts. supply the inner 2/3 of the cortex, according to Medullary arts. supply the inner 2/3 of the cortex, according to some authors; some authors; –– others state endosteal vessels supply more.others state endosteal vessels supply more.

•• Endosteal vessels are dominant in the revascularization and Endosteal vessels are dominant in the revascularization and healing processhealing process •• Outer 1/3 of the cortex supplied by periosteal vesselsOuter 1/3 of the cortex supplied by periosteal vessels –– periosteal vessels especially important in displaced fractures; periosteal vessels especially important in displaced fractures; endosteal vessels often disruptedendosteal vessels often disrupted. . –– Intimate anastomosis exists between muscle and periosteal Intimate anastomosis exists between muscle and periosteal vessels; vessels; –– muscular pumping and muscular vascularity important for muscular pumping and muscular vascularity important for rere--vascularization of external callus. vascularization of external callus. –– Physical therapy and exercise (isometric) important for blood Physical therapy and exercise (isometric) important for blood supplysupply

Three stages of healing:Three stages of healing:•• InflammatoryInflammatory

•• Reparative Reparative

•• Remodeling Remodeling

•• Inflammatory Inflammatory

–– Hematoma formationHematoma formation–– Osteocyte death, vasodilatation migration of acute inflammatory Osteocyte death, vasodilatation migration of acute inflammatory cells into the wound. cells into the wound.

Three stages of healing:Three stages of healing:•• InflammatoryInflammatory

•• Reparative Reparative

•• RemodelingRemodeling

•• ReparativeReparative–– Vascular dilationVascular dilation–– New vessel proliferationNew vessel proliferation–– Mesenchymal cell proliferationMesenchymal cell proliferation–– Change from acid to alkaline pHChange from acid to alkaline pH–– Collagen production in wound Collagen production in wound –– Cartilage and bone fomration beginsCartilage and bone fomration begins

Three stages of healing:Three stages of healing:•• InflammatoryInflammatory

•• Reparative Reparative

•• Remodeling Remodeling

•• RemodelingRemodeling–– osteoblastic resorptioin osteoblastic resorptioin –– new bone formationnew bone formation–– prominent endosteal and periosteal callus formation prominent endosteal and periosteal callus formation

MECHANISMS OF BONE HEALING MECHANISMS OF BONE HEALING •• TWO BASIC TYPES OF CALLUS TWO BASIC TYPES OF CALLUS –– INTERNAL INTERNAL –– EXTERNAL EXTERNAL

EXTERNAL / PERIOSTEAL CALLUS EXTERNAL / PERIOSTEAL CALLUS •• The most reliable radiographic sign of beginning osseous union. The most reliable radiographic sign of beginning osseous union.

•• The fastest type of callus to form The fastest type of callus to form

•• Very dependent upon blood supply of surrounding soft tissues. Very dependent upon blood supply of surrounding soft tissues.

•• more perioteal callus beneath areas of thick soft tissue more perioteal callus beneath areas of thick soft tissue

•• Very tolerant to limited motion at fracture site Very tolerant to limited motion at fracture site

•• Structurally oriented perpendicular to long axis of corticesStructurally oriented perpendicular to long axis of cortices

–– Longitudinal orientation of bone will be re-established upon Longitudinal orientation of bone will be re-established upon remodeling of periosteal callus remodeling of periosteal callus

Periosteal callusPeriosteal callus•• Radial fracture stablized with a pin shows periosteal callusRadial fracture stablized with a pin shows periosteal callus

•• Intramedullary callus seen as band of increased density across Intramedullary callus seen as band of increased density across metaphysis of ulnametaphysis of ulna

EXTERNAL / PERIOSTEAL CALLUS EXTERNAL / PERIOSTEAL CALLUS •• Periosteal callus, because of it's peripheral location, is strongestPeriosteal callus, because of it's peripheral location, is strongest

•• The rigidityThe rigidity--efficiency of the tissue increases with the fourth efficiency of the tissue increases with the fourth power of the distance from the center of rotation or bending.power of the distance from the center of rotation or bending.

•• Periosteal callus does not form in intracapsular areas; no Periosteal callus does not form in intracapsular areas; no

periosteum periosteum --Periosteal callus does not form in flat skull bonesPeriosteal callus does not form in flat skull bones

ENDOSTEAL/INTERNAL ORENDOSTEAL/INTERNAL OR LATE MEDULLARY CALLUS LATE MEDULLARY CALLUS •• Predominates when external/periosteal callus Predominates when external/periosteal callus has failed has failed •• Assisted by rigid immobilization Assisted by rigid immobilization •• Slow, steady bridging Slow, steady bridging •• Medullary callus forms the earliest osseous Medullary callus forms the earliest osseous bridging of fracture line bridging of fracture line

PRIMARY BONE UNION PRIMARY BONE UNION •• Depends upon normal mechanism of bone turnover Depends upon normal mechanism of bone turnover which occurs continuously which occurs continuously •• Must have absolute rigid immobilization; eg. occurs Must have absolute rigid immobilization; eg. occurs when compression plate internal fixation is used properly. when compression plate internal fixation is used properly. •• Primary angiogenic ossification occurs; secondary Primary angiogenic ossification occurs; secondary osteotones form directly without an intervening cartilage osteotones form directly without an intervening cartilage step in development. step in development. –– Longitudinally oriented osteotones formed around blood vessels Longitudinally oriented osteotones formed around blood vessels running across the fracture line.running across the fracture line.

•• Depends on good endosteal circulation. Depends on good endosteal circulation.

•• Very slow process Very slow process

•• Periosteal callus may be minimal if primary bone union Periosteal callus may be minimal if primary bone union is being achieved in conjunction with internal fixation deviceis being achieved in conjunction with internal fixation device

SECONDARY BONE UNION SECONDARY BONE UNION •• Occurs when there is a gap between bone ends Occurs when there is a gap between bone ends (poor apposition and/or alignment) that must be (poor apposition and/or alignment) that must be filled with new bone.filled with new bone.•• Results mostly as result of excessive periosteal Results mostly as result of excessive periosteal callus that undergoes all the intermediate steps of callus that undergoes all the intermediate steps of bone formationbone formation–– Granulation tissue – fibrous tissue – fibrocartilage – Granulation tissue – fibrous tissue – fibrocartilage – woven bone- compact bonewoven bone- compact bone

WHEN IS A FRACTURE "HEALED"?WHEN IS A FRACTURE "HEALED"?•• Clinically: a fracture is healed when there is no Clinically: a fracture is healed when there is no local tenderness or motion of bone across fracture local tenderness or motion of bone across fracture site when manually stressed by examining physician.site when manually stressed by examining physician.–– Clinical union precedes osseous union, and may occur Clinical union precedes osseous union, and may occur in 6in 6--8 weeks, average.8 weeks, average.–– Removal of cast and limited use of the part may be Removal of cast and limited use of the part may be instituted by orthopedist at this timeinstituted by orthopedist at this time–– Clearly visible fracture line may be present on x-rayClearly visible fracture line may be present on x-ray

•• Radiographically: Radiographically: Strict radiographic criterion forStrict radiographic criterion for osseous union is complete obliteration of the fractureosseous union is complete obliteration of the fracture line and evidence of remodeling.line and evidence of remodeling.

WHEN IS A FRACTURE "HEALED"?WHEN IS A FRACTURE "HEALED"?•• For practical purposes, For practical purposes, a fracture with a fracture with bridging callus surrounding 50% of the fracture site bridging callus surrounding 50% of the fracture site with no pain or motion on clinical testing may be with no pain or motion on clinical testing may be considered unitedconsidered united; ; –– patient should avoid rigorous activity until patient should avoid rigorous activity until further healing occursfurther healing occurs

Fracture healing: Favorable factors Fracture healing: Favorable factors

•• FX at bone end where bone is cancellous and blood FX at bone end where bone is cancellous and blood supply good supply good •• Blood supply to fragments not interruptedBlood supply to fragments not interrupted

•• Soft tissue injury mild Soft tissue injury mild

•• End to end apposition of bone fragments End to end apposition of bone fragments

•• No infection at fx site No infection at fx site

•• Adequate immobilization Adequate immobilization

•• Compression of fx with weightbearing Compression of fx with weightbearing

Fracture healing: Unfavorable factors Fracture healing: Unfavorable factors •• Wide separation of fx with soft tissue interposition Wide separation of fx with soft tissue interposition

•• Distraction of fx by traction. Distraction of fx by traction.

•• Severe comminution of fx with extensive ST damage Severe comminution of fx with extensive ST damage

•• Bone lost due to surgery or injury Bone lost due to surgery or injury

•• Poor immobilization; esp. if rotatory motion allowed. Poor immobilization; esp. if rotatory motion allowed.

•• Interrupted blood supply Interrupted blood supply

•• Infection Infection

•• Superimposed systemic illness (diabetes, malnutrition,Superimposed systemic illness (diabetes, malnutrition, --OH) OH) •• Advanced age Advanced age

Incomplete fractures- torus #Incomplete fractures- torus #•• Child or adolescentChild or adolescent

•• Easily overlooked! Potential liability +Easily overlooked! Potential liability +

•• Typically not a serious injury, but bone is weak and Typically not a serious injury, but bone is weak and should be protected to avoid further injuryshould be protected to avoid further injury•• “Buckle” of cortex, typically due to axial loading“Buckle” of cortex, typically due to axial loading

•• Common in distal radiusCommon in distal radius

Incomplete fractures- torus #Incomplete fractures- torus #•• August 14- hx of fall on outstretched hand (next slide follow-up)August 14- hx of fall on outstretched hand (next slide follow-up)

Incomplete fractures- torus #Incomplete fractures- torus #

•• Sept 22- Intramedullary and periosteal callusSept 22- Intramedullary and periosteal callus

Incomplete fractures- plastic deformityIncomplete fractures- plastic deformity•• No focal cortical infraction is visible, but comparison of No focal cortical infraction is visible, but comparison of the left ulna with the normal right side shows visible bendingthe left ulna with the normal right side shows visible bending of the bone of the bone

Stress fracturesStress fractures•• Weight bearing bones espWeight bearing bones esp–– 22ndnd MT MT–– TibiaTibia–– FibulaFibula–– CalcaneusCalcaneus

•• Healing response is often 1Healing response is often 1stst plain film finding plain film finding

•• MR very sensitive to marrow edema changes for early MR very sensitive to marrow edema changes for early Dx.Dx.

Stress fractures- “March” fractureStress fractures- “March” fracture•• Fx healing is first plain film findingFx healing is first plain film finding

•• 22ndnd MT most common MT most common

•• Seen in army recruits marching with heavy packsSeen in army recruits marching with heavy packs

•• Also seen in runners orAlso seen in runners or

•• Patient with altered gait pattern may developPatient with altered gait pattern may develop–– Bunion, post-surg, etc.Bunion, post-surg, etc.

Stress fractures- “March” fractureStress fractures- “March” fracture•• Fx healing is first plain film findingFx healing is first plain film finding

•• 22ndnd MT most common MT most common

•• Seen in army recruits marching with heavy packsSeen in army recruits marching with heavy packs

•• Also seen in runners orAlso seen in runners or

•• Patient with altered gait pattern may developPatient with altered gait pattern may develop–– Bunion, post-surg, etc.Bunion, post-surg, etc.

Stress fractures- tibiaStress fractures- tibia•• Runners/joggersRunners/joggers

•• Otherwise inactive individuals beginning an aggressive Otherwise inactive individuals beginning an aggressive exercise program of walkingexercise program of walking•• May be dx as “shin splints”May be dx as “shin splints”

Chronic traumaChronic traumaX-ray of elderly Chinese woman- dx?X-ray of elderly Chinese woman- dx?

Why at least 2 views?Why at least 2 views?AP film of patient with recent trauma- do you really need AP film of patient with recent trauma- do you really need

another film?another film?

SpondylolysisSpondylolysis•• Many (?most?) are the result of stress fractureMany (?most?) are the result of stress fracture

•• Acute pathogenesis is supported by someAcute pathogenesis is supported by some

•• IncidenceIncidence–– 3-7% in US, with higher numbers in Eskimo population3-7% in US, with higher numbers in Eskimo population–– Incid rises from age 3 – 20 yrs., then does not increase in Incid rises from age 3 – 20 yrs., then does not increase in frequencyfrequency–– 2:1 male prediliction2:1 male prediliction–– Increased incidence in association with spina bifidaIncreased incidence in association with spina bifida•• Seen by some as evidence of congenital etiology, it more likely represents theSeen by some as evidence of congenital etiology, it more likely represents the additional stress created by an open vs a closed ring.additional stress created by an open vs a closed ring.

•• L5 most common (67%), then L4 > L3 >L2L5 most common (67%), then L4 > L3 >L2

•• Cervical spine not commonly involved, but C6 Cervical spine not commonly involved, but C6 predilictedpredilicted•• Most often bilateral, but may be unilateralMost often bilateral, but may be unilateral

•• Displacement usually occurs within first two years, if at Displacement usually occurs within first two years, if at allall

SpondylolysisSpondylolysis•• Myerding gradingMyerding grading–– Divide sacral base into 1/4ths from back P to ADivide sacral base into 1/4ths from back P to A–– Into which 1/4Into which 1/4thth does a line along posterior aspect L5 vert body does a line along posterior aspect L5 vert body fall?fall?–– Grades I-IV; Grade V if spondyloptosis occurs.Grades I-IV; Grade V if spondyloptosis occurs.

•• % assessment% assessment–– Estimate displacement of L5 relative to the total (100%) P-A Estimate displacement of L5 relative to the total (100%) P-A measurement of sacral base. measurement of sacral base.

SpondylolysisSpondylolysis•• L4 spondylolysisL4 spondylolysis

SpondylolysisSpondylolysis

•• May be unstable- flexion/extension may be usefulMay be unstable- flexion/extension may be useful

SpondylolysisSpondylolysis•• Spondyloptosis may occurSpondyloptosis may occur

•• “inverted Napolean hat” sign on AP view due to overlap“inverted Napolean hat” sign on AP view due to overlap of L5 on sacral baseof L5 on sacral base

SpondylolysisSpondylolysis•• Cervical spondyolysis most common at C6Cervical spondyolysis most common at C6

•• Spina bifida is typically associatedSpina bifida is typically associated

•• Instability may be presentInstability may be present

Fractures involving the growth plateFractures involving the growth plate•• Salter-Harris classificationSalter-Harris classification–– Type I = A “slip” of the epiphysis due to separation thruType I = A “slip” of the epiphysis due to separation thru the physis- injury to cartilage platethe physis- injury to cartilage plate–– Type II – “Slip and a chip”; fracture thru physeal plate Type II – “Slip and a chip”; fracture thru physeal plate and obliquely thru corner of adjacent metaphysisand obliquely thru corner of adjacent metaphysis–– Type III – “A Slip and a crack”; fracture thru epiphysis Type III – “A Slip and a crack”; fracture thru epiphysis (crack), across physis (slip) (crack), across physis (slip) –– Type IV – Fracture thru epiphysis, physis and Type IV – Fracture thru epiphysis, physis and metaphysis; no significant slippage of physis/metaphysismetaphysis; no significant slippage of physis/metaphysis–– Type V – Compression/impaction injury of physisType V – Compression/impaction injury of physis

Salter-Harris # Type ISalter-Harris # Type I•• Approx. 6% of epiphyseal fracturesApprox. 6% of epiphyseal fractures

•• Common locations are distal extremitiesCommon locations are distal extremities

•• Easily overlooked without complete seriesEasily overlooked without complete series

•• Slipped Femoral Capital Epiphysis (SFCE) is a Slipped Femoral Capital Epiphysis (SFCE) is a chronically acquired S-H type I fracturechronically acquired S-H type I fracture

Salter-Harris # Type ISalter-Harris # Type I•• Note the tibial physis is closedNote the tibial physis is closed

•• Offset seen on oblique and wide physis on lateralOffset seen on oblique and wide physis on lateral

Salter-Harris # Type IISalter-Harris # Type II•• Most common (75%) of the Salter-Harris #sMost common (75%) of the Salter-Harris #s

•• Easily overlooked without complete seriesEasily overlooked without complete series

•• Approx. 50% in distal radiusApprox. 50% in distal radius

Salter-Harris # Type IISalter-Harris # Type II•• What kind of Salter-Harris injury is present?What kind of Salter-Harris injury is present?

•• What other injury is also present?What other injury is also present?

Salter-Harris # Type IIISalter-Harris # Type III•• Fracture thru epiphysis (crack) and across physis (slip)Fracture thru epiphysis (crack) and across physis (slip)

•• Approx. 8% of all epiphyseal fracturesApprox. 8% of all epiphyseal fractures

Salter-Harris # Type IIISalter-Harris # Type III•• Most common location is distal tibiaMost common location is distal tibia

•• Optimal reduction especially important due to Optimal reduction especially important due to involvement of articular surfaceinvolvement of articular surface

Salter-Harris # Type IVSalter-Harris # Type IV•• Fracture extends thru metaphysis, physis and epiphysisFracture extends thru metaphysis, physis and epiphysis

•• Most common sites are lateral condyle of humerus and Most common sites are lateral condyle of humerus and distal tibiadistal tibia•• Approx. 10% of epiphyseal plate fracturesApprox. 10% of epiphyseal plate fractures

•• Open reduction typically performedOpen reduction typically performed

Salter-Harris # Type VSalter-Harris # Type V•• Easily overlooked! Initial films may be negativeEasily overlooked! Initial films may be negative–– MR much more sensitive!MR much more sensitive!

•• Least common of S-H typesLeast common of S-H types

•• Compressive mechanism of injuryCompressive mechanism of injury

•• Early growth plate closure may result in limb-length Early growth plate closure may result in limb-length problemsproblems•• Distal tibia and femur most commonDistal tibia and femur most common

Complications of fractureComplications of fracture•• ImmediateImmediate–– Arterial injuryArterial injury–– Compartment syndromeCompartment syndrome–– GasgangreneGasgangrene–– Fat embolismFat embolism–– ThromboembolismThromboembolism

•• LaterLater–– OsteonecrosisOsteonecrosis

–– DJDDJD–– OsteoporosisOsteoporosis–– Aneurysmal bone cystAneurysmal bone cyst–– Non unionNon union–– malunionmalunion

•• IntemediateIntemediate–– OsteomyelitisOsteomyelitis–– hardware failurehardware failure–– Reflex sympathetic dystrophyReflex sympathetic dystrophy–– Post-traumatic osteolysisPost-traumatic osteolysis–– RefractureRefracture–– Myositis ossificansMyositis ossificans–– SynostosisSynostosis–– Delayed unionDelayed union

Complications of fractureComplications of fractureDelayed vs Non-unionDelayed vs Non-union•• Delayed union = fracture has not united at the average Delayed union = fracture has not united at the average time for the location and type of fracture.time for the location and type of fracture.–– Expected healing time quite variable based on site and any Expected healing time quite variable based on site and any favorable/unfavorable factors; favorable/unfavorable factors; –– “delayed” is relative term.“delayed” is relative term.

Complications: Delayed vs Non-unionComplications: Delayed vs Non-union•• NonNon--union = the repair process has completely stopped and union = the repair process has completely stopped and union will not occur without surgical intervention.union will not occur without surgical intervention.

•• Hypertrophic non-union: demonstrates extensive callus Hypertrophic non-union: demonstrates extensive callus formation, but callus does not bridge; # line persists.formation, but callus does not bridge; # line persists.–– Associated with local hypervascularityAssociated with local hypervascularity–– Rigid internal fixation may be sufficient to allow union to occur.Rigid internal fixation may be sufficient to allow union to occur.–– "Elephant foot" or "horse's hoof" appearance. "Elephant foot" or "horse's hoof" appearance.

•• Atrophic type non-union: minimal callus, if any; # line persists. Atrophic type non-union: minimal callus, if any; # line persists. –– Incapable of biologic reaction; associated with avascularity.Incapable of biologic reaction; associated with avascularity.–– Requires more aggressive surgical interventionRequires more aggressive surgical intervention

•• Radiographically, the nonRadiographically, the non--union is characterized by a closing of union is characterized by a closing of the medullary canal with cortical bone. the medullary canal with cortical bone.

Non-unionNon-union

•• Smoothly corticated margins and closed medullary canal on left Smoothly corticated margins and closed medullary canal on left characterize atrophic non-union of fibulacharacterize atrophic non-union of fibula•• Residual fracture line despite bone proliferation and sclerosis in Residual fracture line despite bone proliferation and sclerosis in middle frame shows hypertrophic non-unionmiddle frame shows hypertrophic non-union•• Far right frame shows malunited fibula and non-union of the tibiaFar right frame shows malunited fibula and non-union of the tibia

Non-union- what type?Non-union- what type?•• Hypertrophic “elephant foot” appearanceHypertrophic “elephant foot” appearance

MalunionMalunion•• This case from Greenspan’s text shows residual angularThis case from Greenspan’s text shows residual angular deformity from a united both-bones fracture of the lower leg deformity from a united both-bones fracture of the lower leg (reading left) and subsequent surgical intervention (right) to (reading left) and subsequent surgical intervention (right) to restore alignment.restore alignment.

Early growth plate closureEarly growth plate closure•• Length disparity and deformity secondary to central Length disparity and deformity secondary to central ossification across physeal plate of distal left femurossification across physeal plate of distal left femur•• Distal tibia shows ossification across posterior part of Distal tibia shows ossification across posterior part of physeal plate, while anterior part not joined. Also note physeal plate, while anterior part not joined. Also note deformity of fibula and disparity of length relative to tibia. deformity of fibula and disparity of length relative to tibia. •• (Cases from Greenspan text)(Cases from Greenspan text)

Avascular necrosisAvascular necrosis•• 41 yr. old man with hx of traumatic hip dislocation41 yr. old man with hx of traumatic hip dislocation

•• Note the irregular, mixed sclerosis and cystic lucency ofNote the irregular, mixed sclerosis and cystic lucency of the femoral headthe femoral head•• Frog-leg projection shows classic “cresent sign” Frog-leg projection shows classic “cresent sign”

Avascular necrosisAvascular necrosis•• 56 yr. old female with hx of intracapsular fx of femoral neck 56 yr. old female with hx of intracapsular fx of femoral neck which healed after internal fixation device applied.which healed after internal fixation device applied.•• Irregular sclerosis of femoral head (best seen in tomo on rt) Irregular sclerosis of femoral head (best seen in tomo on rt) consistent with avascular necrosisconsistent with avascular necrosis

Disuse osteoporosisDisuse osteoporosis•• These examples from Greenspan’s text show disuse osteoporosisThese examples from Greenspan’s text show disuse osteoporosis that may accompany united (left) or ununited (right) fractures. The that may accompany united (left) or ununited (right) fractures. The appearance may be alarming, although not necessarily of clinical appearance may be alarming, although not necessarily of clinical importance.importance.

Chronic Regional Pain Syndrome-Chronic Regional Pain Syndrome-Reflex Sympathetic Dystrophy (RSD)Reflex Sympathetic Dystrophy (RSD)•• Also previously reported as Sudeck’s atrophy or causalgiaAlso previously reported as Sudeck’s atrophy or causalgia

•• Believed to be associated with antidromal sympathetic input to Believed to be associated with antidromal sympathetic input to the CNS secondary to trauma to peripheral trauma; overt fracture, the CNS secondary to trauma to peripheral trauma; overt fracture, neural or vascular injury may or may not be present.neural or vascular injury may or may not be present.•• Characterized by excessive pain (causalgia), not relieved by Characterized by excessive pain (causalgia), not relieved by immobilization.immobilization.•• Initial soft tissue swelling followed by atrophy of skin/musclesInitial soft tissue swelling followed by atrophy of skin/muscles

•• Predominant X-ray findings are rapidly developing, patchy Predominant X-ray findings are rapidly developing, patchy osteoporosis distal to site of injury and changes (early, swelling; later, osteoporosis distal to site of injury and changes (early, swelling; later, atrophy)atrophy)

Reflex Sympathetic Dystrophy (RSD)Reflex Sympathetic Dystrophy (RSD)•• AKA: Sudeck’s atrophyAKA: Sudeck’s atrophy•• Believed to be associated with antidromal sympathetic input to the CNS Believed to be associated with antidromal sympathetic input to the CNS secondary to trauma to peripheral trauma; overt fracture, neural or vascular injury secondary to trauma to peripheral trauma; overt fracture, neural or vascular injury may or may not be present.may or may not be present.•• Characterized by excessive pain (causalgia), not relieved by immobilization.Characterized by excessive pain (causalgia), not relieved by immobilization.•• Initial soft tissue swelling followed by atrophy of skin/musclesInitial soft tissue swelling followed by atrophy of skin/muscles•• Predominant X-ray findings are rapidly developing, patchy osteoporosis distal Predominant X-ray findings are rapidly developing, patchy osteoporosis distal to site of injury and changes (early, swelling; later, atrophy)to site of injury and changes (early, swelling; later, atrophy)

InfectionInfection•• Both bones # with attempted internal fixation (left)Both bones # with attempted internal fixation (left)

•• 8 weeks later tibia shows motheaten destruction 8 weeks later tibia shows motheaten destruction compatible with osteomyelitis (right)compatible with osteomyelitis (right)

Post-traumatic Myositis Ossificans Post-traumatic Myositis Ossificans •• Usually following an injury with significant soft tissue Usually following an injury with significant soft tissue bleeding/hematoma formation, especially deeper tissues.bleeding/hematoma formation, especially deeper tissues.•• Soft tissue mass forms with calcific deposition Soft tissue mass forms with calcific deposition beginning in 3-4 weeks.beginning in 3-4 weeks.•• Peripheral calcification of mass is more advanced than Peripheral calcification of mass is more advanced than centralcentral–– Ddx periosteal o-sarcDdx periosteal o-sarc

•• Calcification may be re-organized to ossificationCalcification may be re-organized to ossification

Post-traumatic Myositis OssificansPost-traumatic Myositis Ossificans

•• This AP projection of the thigh demonstrates This AP projection of the thigh demonstrates ossification along the plane of adductor muscles as a result ossification along the plane of adductor muscles as a result of previous injury.of previous injury.

Shoulder- dislocationShoulder- dislocation•• Most common presenting dislocationMost common presenting dislocation

•• 95% are anterior95% are anterior–– Subcoracoid (most common)Subcoracoid (most common)–– SubglenoidSubglenoid–– SubclavicularSubclavicular–– Intrathoracic (rarely)Intrathoracic (rarely)

•• Commonly associated injuriesCommonly associated injuries–– Hills-Sachs lesionHills-Sachs lesion–– Bankhart lesionBankhart lesion

Shoulder- Hills-Sachs lesionShoulder- Hills-Sachs lesion•• Compression fx of the posterolateral aspect of humeralCompression fx of the posterolateral aspect of humeral head from impact against the antero-inferior aspect of the head from impact against the antero-inferior aspect of the glenoid fossa.glenoid fossa.•• Creates a “hatchet” deformityCreates a “hatchet” deformity

Shoulder- Hills-Sachs lesionShoulder- Hills-Sachs lesion•• Axillary (inferior to superior) view shows “hatchet” Axillary (inferior to superior) view shows “hatchet” deformity of antero-medial humeral head in patient with a deformity of antero-medial humeral head in patient with a posterior dislocation.posterior dislocation.

Shoulder- Posterior dislocationShoulder- Posterior dislocation•• Note the overlap of the humeral head over the glenoid, Note the overlap of the humeral head over the glenoid, despite the tangential position of the glenoid fossa.despite the tangential position of the glenoid fossa.

Shoulder- Posterior dislocationShoulder- Posterior dislocation•• Note the posterior position of the humerus on the “y-Note the posterior position of the humerus on the “y-view” of the shoulderview” of the shoulder

Shoulder- Bankhart lesionShoulder- Bankhart lesion•• Bankhart lesionBankhart lesion results from contact of the humeral results from contact of the humeral head against the inferior margin of the glenoid fossahead against the inferior margin of the glenoid fossa•• Bony injury may result, however isolated injury to the Bony injury may result, however isolated injury to the cartilagenous labrum may occur cartilagenous labrum may occur –– Plain film negative for cartilage injuryPlain film negative for cartilage injury

Shoulder- Bankhart lesionShoulder- Bankhart lesion•• Note the cortical irregularity of the inferior glenoid Note the cortical irregularity of the inferior glenoid marginmargin

Shoulder- “flap” fractureShoulder- “flap” fracture•• Thin “flap” of bone from lateral humeral head, Thin “flap” of bone from lateral humeral head, extending into adjacent metaphysis- displaced more at extending into adjacent metaphysis- displaced more at inferior aspectinferior aspect•• Is the humerus also dislocated?Is the humerus also dislocated?

Shoulder- Gr. Tub. # and dislocShoulder- Gr. Tub. # and disloc•• Thin “flap” of bone from lateral humeral headThin “flap” of bone from lateral humeral head

•• Is the humerus also dislocated?Is the humerus also dislocated?

Rotator cuff tear-chronic Rotator cuff tear-chronic •• Acromio-humeral space should be measured on the external Acromio-humeral space should be measured on the external rotation projectionrotation projection•• Measurement of 7mm or less is strong indication of chronic Measurement of 7mm or less is strong indication of chronic rotator cuff tearrotator cuff tear–– NO relevance to acute tears!NO relevance to acute tears!

Chronic rotator cuff tear + DJD of ACChronic rotator cuff tear + DJD of AC•• Decrease acromio-humeral space and inferior AC joint Decrease acromio-humeral space and inferior AC joint osteophyte formation contribute to impingement syndrome and may osteophyte formation contribute to impingement syndrome and may precipitate rotator cuff tear precipitate rotator cuff tear •• Dec. acromio-humeral space = strong suspicion of chronic cuff Dec. acromio-humeral space = strong suspicion of chronic cuff teartear

Shoulder- AC jointShoulder- AC joint•• Fall on “point” of shoulder typical hx for AC joint Fall on “point” of shoulder typical hx for AC joint separationseparation•• Grade I sprain = normal x-rays; clinical diagnosisGrade I sprain = normal x-rays; clinical diagnosis•• Grade II sprain = Stress views show more than Grade II sprain = Stress views show more than 3-4mm difference in coraco-clavicular space 3-4mm difference in coraco-clavicular space compared to un-injured sidecompared to un-injured side•• Grade III sprain = complete coraco-clavicular lig Grade III sprain = complete coraco-clavicular lig disruption evidenced by a 40 – 50% increase in disruption evidenced by a 40 – 50% increase in coraco-clavicular space (compared to non-injured coraco-clavicular space (compared to non-injured side); 5mm or more difference side-to-sideside); 5mm or more difference side-to-side

Acromioclavicular joint assessmentAcromioclavicular joint assessment•• Diagram and table from GreenspanDiagram and table from Greenspan

Stress view for AC jointsStress view for AC joints•• Note the passive attachment of weight to arms to avoidNote the passive attachment of weight to arms to avoid active contraction of the shoulder musclesactive contraction of the shoulder muscles•• Can be performed as single view including both AC Can be performed as single view including both AC joints on 7x17 film, if anatomy will fit; otherwise single viewsjoints on 7x17 film, if anatomy will fit; otherwise single views on either side.on either side.

AC joint fx-dislocationAC joint fx-dislocationAC joint dislocationAC joint dislocation•• Normal AC joint space usually 4-5mm max, but up to Normal AC joint space usually 4-5mm max, but up to 8mm may still be normal8mm may still be normal•• Alignment of inferior margin of joint more reliable than Alignment of inferior margin of joint more reliable than superior marginsuperior margin•• Normal coraco-clavicular space 13mm maximumNormal coraco-clavicular space 13mm maximum–– Gr III sprain likely if more than 50% difference side-side in space Gr III sprain likely if more than 50% difference side-side in space

AC joint sprain grade IIIAC joint sprain grade IIIGrade III AC joint separationGrade III AC joint separationComplication- Post-traumatic osteolysisComplication- Post-traumatic osteolysis

•• May occur secondary to acute trauma (with or without May occur secondary to acute trauma (with or without dislocation)dislocation)•• May also occur in repetitive traumaMay also occur in repetitive trauma–– Weight-liftingWeight-lifting

•• Has been reported in many other locations, but distal clavicle is Has been reported in many other locations, but distal clavicle is most commonmost common•• Soft tissue swelling and osteopenia, followed by resorption of Soft tissue swelling and osteopenia, followed by resorption of distal end of clavicledistal end of clavicle•• May appear irregular or “clean” – almost surgicalMay appear irregular or “clean” – almost surgical

Post-traumatic osteolysis- claviclePost-traumatic osteolysis- clavicle•• Later, marked AC jnt widening due to resorptionLater, marked AC jnt widening due to resorption–– Progresses over 12-18 mos.Progresses over 12-18 mos.–– Up to 3 cm resorptionUp to 3 cm resorption

•• Process is self-limitingProcess is self-limiting–– Reparative stage occurs over 4-6 monthsReparative stage occurs over 4-6 months–– Some residual widening of AC joint may persistSome residual widening of AC joint may persist

•• Typical age range 20-40Typical age range 20-40

•• Acute trauma or repetitive stress may precipitateAcute trauma or repetitive stress may precipitate–– Weightlifters and those employed in heavy lifting occupationsWeightlifters and those employed in heavy lifting occupations

•• Mechanism not well understood. Non-specific Mechanism not well understood. Non-specific synovitis?synovitis?

Post-traumatic osteolysis- claviclePost-traumatic osteolysis- clavicle•• MR findings may support diagnosisMR findings may support diagnosis

Clavicle fractureClavicle fracture•• LocationLocation–– Fx can be classified according to location in the medial Fx can be classified according to location in the medial (type I), middle (type II) of lateral (type III) third of bone(type I), middle (type II) of lateral (type III) third of bone–– 75-80% of fx occurs in the middle portion of bone75-80% of fx occurs in the middle portion of bone•• Esp near junction of outer and middle 1/3’s of boneEsp near junction of outer and middle 1/3’s of bone–– Only 5% affect the medial endOnly 5% affect the medial end–– 15-20% occur at distal end15-20% occur at distal end

•• Fx which leaves the coraco-clavicular lig intact Fx which leaves the coraco-clavicular lig intact are much more stable and more likely to healare much more stable and more likely to heal

•• Exuberant callus formation of clavicle fx may Exuberant callus formation of clavicle fx may cause thoracic outlet syndromecause thoracic outlet syndrome

Clavicle fractureClavicle fractureClavicle fractureClavicle fracture•• 12 yr old boy with history of trauma to shoulder 2-3 12 yr old boy with history of trauma to shoulder 2-3 weeks agoweeks ago

Elbow fracturesElbow fractures•• Radial head fx is most common adult elbow fractureRadial head fx is most common adult elbow fracture–– Take oblique view in addition to AP/lat!Take oblique view in addition to AP/lat!

•• Remember- the posterior fat pad is NOT normally Remember- the posterior fat pad is NOT normally visible on the lateral x-rayvisible on the lateral x-ray–– In child with hx of trauma this is a reliable sign of fractureIn child with hx of trauma this is a reliable sign of fracture

Normal elbow alignmentNormal elbow alignment•• Radiocapitellar line: Normally, a line through neck and midpoint Radiocapitellar line: Normally, a line through neck and midpoint of radial head should pass through the capitellum in all projections. of radial head should pass through the capitellum in all projections. •• Anterior humeral line: Line along the anterior humeral cortex on Anterior humeral line: Line along the anterior humeral cortex on a lateral elbow projection should intersect the middle 1/3 of capitellum.a lateral elbow projection should intersect the middle 1/3 of capitellum.

Trauma- Fat pad signTrauma- Fat pad sign•• Visiblity of the posterior fat pad in a pediatric patient with a Visiblity of the posterior fat pad in a pediatric patient with a history of trauma is strongly indicative (90%+) of fracturehistory of trauma is strongly indicative (90%+) of fracture•• Visibility of anterior fat pad is normal- but displacement is not!Visibility of anterior fat pad is normal- but displacement is not!

•• No obvious fx, but visible posterior fat pad (positive fat No obvious fx, but visible posterior fat pad (positive fat pad sign) and displaced anterior fat pad (“sail sign”)pad sign) and displaced anterior fat pad (“sail sign”)

Trauma- Trauma- •• Ulnar fracture with radial head dislocationUlnar fracture with radial head dislocation

Trauma- supracondylar #Trauma- supracondylar #•• Initial exam (left) somewhat light; fracture more easily Initial exam (left) somewhat light; fracture more easily seen on darker repeat lateralseen on darker repeat lateral

Trauma- supracondylar #Trauma- supracondylar #

•• Abnormal anterior humeral lineAbnormal anterior humeral line

Radial head fxRadial head fxRadial head fxRadial head fxElbow fracturesElbow fractures•• Supracondylar fracture is most common pediatric elbowSupracondylar fracture is most common pediatric elbow fracturefracture•• Injury to the brachial artery or median nv. may occur Injury to the brachial artery or median nv. may occur with significant displacementwith significant displacement

Nursemaid’s elbowNursemaid’s elbow•• Eponyms: Goyrand's injury / Malgaigne's luxation Eponyms: Goyrand's injury / Malgaigne's luxation

•• Mechanism: subluxation of radial head distally to annular Mechanism: subluxation of radial head distally to annular ligament such that the lig. becomes interposed between the capitellumligament such that the lig. becomes interposed between the capitellum and radial head. and radial head. •• Typically occurs when small child is lifted forcibly by axial Typically occurs when small child is lifted forcibly by axial distraction on forearm. distraction on forearm. •• Occurs before the radial head is fully developed (prior to age 6 )Occurs before the radial head is fully developed (prior to age 6 )

•• Most common at age 2; not common after age 8. Most common at age 2; not common after age 8.

•• Clinical presentation Clinical presentation –– .Rubbery resistance to passive supination and extension of elbow. .Rubbery resistance to passive supination and extension of elbow. –– Arm held in flexion approx. 20 degrees and slight pronation. Arm held in flexion approx. 20 degrees and slight pronation.

•• Treatment: reduction without anaesthesia by anteriorward Treatment: reduction without anaesthesia by anteriorward pressure on pressure on radial head with thumb as elbow is slowly extended radial head with thumb as elbow is slowly extended and supinated; occasionally, flexion and pronation of elbow may also and supinated; occasionally, flexion and pronation of elbow may also be needed. be needed. •• X-rays are negativeX-rays are negative

Forearm fracturesForearm fractures•• Monteggia fxMonteggia fx–– Fx of ulna with dislocation of radial headFx of ulna with dislocation of radial head–– This example is a non-united Monteggia fx in a patient with a This example is a non-united Monteggia fx in a patient with a who gave a history of “recent trauma”who gave a history of “recent trauma”

Forearm fracturesForearm fractures•• Monteggia fxMonteggia fx–– Pediatric patient (right)Pediatric patient (right)–– Adult patient (below)Adult patient (below)

Forearm fracturesForearm fractures•• Galeazzi FractureGaleazzi Fracture–– Fx of radius with diastasis of the distal radio-ulnar joint (two Fx of radius with diastasis of the distal radio-ulnar joint (two different cases)different cases)

Wrist injuriesWrist injuries•• Distal radius or ulna fx 10X more common than carpal Distal radius or ulna fx 10X more common than carpal bone fx.bone fx.•• Colle’s fxColle’s fx–– Fx. distal radial metaphysis with dorsalangulationFx. distal radial metaphysis with dorsalangulation–– +/- intra-articular involvement+/- intra-articular involvement–– Assoc. ulnar styloid fx often due to attachment of triangular Assoc. ulnar styloid fx often due to attachment of triangular cartilagecartilage–– Usually cause is fall on outstretched handUsually cause is fall on outstretched hand

Colle’s fxColle’s fx•• Note- even with the impacted fx, the distal radial Note- even with the impacted fx, the distal radial articular surface has lost normal volar slant (see below diag)articular surface has lost normal volar slant (see below diag)

•• Force applied thru TFCC to ulnar styloid may cause avulsion Force applied thru TFCC to ulnar styloid may cause avulsion injury in Colles fx.injury in Colles fx.

Wrist injuriesWrist injuries•• Colle’s fxColle’s fx–– Fx. distal radial metaphysis with dorsalangulationFx. distal radial metaphysis with dorsalangulation–– +/- intra-articular involvement+/- intra-articular involvement–– Assoc. ulnar styloid fx often due to attachment of triangular Assoc. ulnar styloid fx often due to attachment of triangular cartilagecartilage–– Usually cause is fall on outstretched handUsually cause is fall on outstretched hand

Wrist injuriesWrist injuries•• Smith’s fxSmith’s fx–– Fx distal radius with palmar displacementFx distal radius with palmar displacement–– Articular surface not involved (case below most likely does have Articular surface not involved (case below most likely does have articular involvement)articular involvement)

Wrist injuriesWrist injuries•• Barton’s fxBarton’s fx–– Fx of the dorsal rim of the radius due to impaction of carpusFx of the dorsal rim of the radius due to impaction of carpus•• Barton originally described either dorsal or palmar rim fxBarton originally described either dorsal or palmar rim fx–– By definition, an intra-articular fractureBy definition, an intra-articular fracture–– Carpus is dislocated or subluxed in addition to fractureCarpus is dislocated or subluxed in addition to fracture

Wrist injuriesWrist injuries•• Barton’s fxBarton’s fx–– Equivocal plain film (right)Equivocal plain film (right)–– T1 MR demonstrates definite loss of signal due to edema and T1 MR demonstrates definite loss of signal due to edema and linear linear

Wrist injuriesWrist injuries•• Both bones fracture distal forearmBoth bones fracture distal forearm–– Distal radial meta-diaphysis # with posterior displacement Distal radial meta-diaphysis # with posterior displacement –– Salter-Harris # distal ulna with posterior displacement (?Type I or II?)Salter-Harris # distal ulna with posterior displacement (?Type I or II?)

Wrist injuriesWrist injuries•• Hutchinson fxHutchinson fx–– Fx radial styloid processFx radial styloid process–– Involves the articular surfaceInvolves the articular surface–– AKA “Chauffeur’s fx”AKA “Chauffeur’s fx”–– Brachioradialis m. inserts on the radial styloid, therefore usually Brachioradialis m. inserts on the radial styloid, therefore usually above elbow castabove elbow cast

Carpal injuriesCarpal injuries•• Scapholunate dissociationScapholunate dissociation–– Scapho-lunate space >2mm is suspicious and >4mm is Scapho-lunate space >2mm is suspicious and >4mm is diagnostic of rupture of scapho-lunate ligamentdiagnostic of rupture of scapho-lunate ligament–– “Terry Thomas” sign“Terry Thomas” sign–– Clenched fist view may be useful to emphasize this findingClenched fist view may be useful to emphasize this finding

Carpal injuriesCarpal injuries•• More recently, the “Terry Thomas sign” has been More recently, the “Terry Thomas sign” has been referred to as the “David Letterman sign”. referred to as the “David Letterman sign”.

Carpal injuriesCarpal injuries•• Scapholunate dissociationScapholunate dissociation–– Scapho-lunate space >2mm is suspicious and >4mm is Scapho-lunate space >2mm is suspicious and >4mm is diagnostic of rupture of scapho-lunate ligamentdiagnostic of rupture of scapho-lunate ligament–– “Terry Thomas” sign“Terry Thomas” sign–– Clenched fist view may be useful to emphasize this findingClenched fist view may be useful to emphasize this finding

Ruptured scapholunate ligamentRuptured scapholunate ligament•• MR examination is very sensitive for evaluation of the MR examination is very sensitive for evaluation of the scapholunate ligamentscapholunate ligament

Vascular supply to scaphoidVascular supply to scaphoid•• Far left shows nutrient foramina along entire length Far left shows nutrient foramina along entire length

•• Types at middle and right have vessels entering distallyTypes at middle and right have vessels entering distally and running intraosseous course to supply the proximal pole.and running intraosseous course to supply the proximal pole. –– More predisposed to AVN if fx thru waist occursMore predisposed to AVN if fx thru waist occurs

Carpal injuries- scaphoid fxCarpal injuries- scaphoid fx•• Most commonly fx carpal bone (50-70%)Most commonly fx carpal bone (50-70%)

•• Reported union rate varies (50-95%)Reported union rate varies (50-95%)

•• Prognosis improves with more distal fx, worse if Prognosis improves with more distal fx, worse if proximal 1/3proximal 1/3•• Subtle if not displacedSubtle if not displaced–– fx line at 2 wks may more clearly seen fx line at 2 wks may more clearly seen

•• Delayed union not uncommonDelayed union not uncommon–– May take 6 – 12 mos.May take 6 – 12 mos.

Ulnar deviation view of wristUlnar deviation view of wrist•• Ulnar deviation view may help identify scaphoid waist fxUlnar deviation view may help identify scaphoid waist fx

•• Scaphoid flexes in radial deviation and transverse fx line better Scaphoid flexes in radial deviation and transverse fx line better aligned to CR in ulnar deviationaligned to CR in ulnar deviation•• (film below shows positioning- no fracture present(film below shows positioning- no fracture present

Carpal injuries- scaphoid fxCarpal injuries- scaphoid fxCarpal injuries- scaphoid fxCarpal injuries- scaphoid fx•• Scaphoid fracture oblique thru waistScaphoid fracture oblique thru waist

Carpal injuries- scaphoid fxCarpal injuries- scaphoid fxWhat x-ray changes suggest a poor outcome?What x-ray changes suggest a poor outcome?

Carpal injuries- scaphoid fxCarpal injuries- scaphoid fx•• May occur in association with dislocations of carpus, May occur in association with dislocations of carpus, particularly lunate or perilunate dislocationparticularly lunate or perilunate dislocation•• “transcaphoid-perilunate fracture dislocation” seen “transcaphoid-perilunate fracture dislocation” seen belowbelow

Carpal injuries- triquetrum fxCarpal injuries- triquetrum fx•• 22ndnd most common fx most common fx

•• Usually dorsal avulsion injuryUsually dorsal avulsion injury

•• Triquetrum normally forms the posterior “horizon” of Triquetrum normally forms the posterior “horizon” of the mid-carpus on lateral film; look here for fx.the mid-carpus on lateral film; look here for fx.

Perilunate dislocationPerilunate dislocation•• Dislocation of carpus from lunate- this case has associated # Dislocation of carpus from lunate- this case has associated # radiusradius•• Note the position of the lunate/capitate on lateral viewNote the position of the lunate/capitate on lateral view

•• “pie-shaped” or triangular appearance of lunate on PA view“pie-shaped” or triangular appearance of lunate on PA view

Carpal injuries- DISI and VISICarpal injuries- DISI and VISI•• DISI = dorsal intercalated segment instabilityDISI = dorsal intercalated segment instability

•• VISI = volar intercalated segment instabilityVISI = volar intercalated segment instability

•• Both defined by the relationship of the lunate to the Both defined by the relationship of the lunate to the capitatecapitate•• Scapho-lunate angle is altered in either deformityScapho-lunate angle is altered in either deformity

Carpal injuries- DISI and VISICarpal injuries- DISI and VISI•• Scapho-lunate angle is typically 30-60 degreesScapho-lunate angle is typically 30-60 degrees–– Note- scapholunate angle changes with lateral flexionNote- scapholunate angle changes with lateral flexion

•• In DISI, the lunate rotates posteriorly, and/or scaphoid In DISI, the lunate rotates posteriorly, and/or scaphoid anteriorly, causing increased scapho-lunate angleanteriorly, causing increased scapho-lunate angle•• Usually assoc with rupture of scapho-lunate ligamentUsually assoc with rupture of scapho-lunate ligament

Carpal injuries- DISI and VISICarpal injuries- DISI and VISI•• In VISI, the lunate rotates anteriorly, and/or the In VISI, the lunate rotates anteriorly, and/or the scaphoid rotates posteriorly, causing decreased scapho-scaphoid rotates posteriorly, causing decreased scapho-lunate anglelunate angle•• Usually assoc with rupture of the lunate-triquetral Usually assoc with rupture of the lunate-triquetral ligament or mid-carpal sprainsligament or mid-carpal sprains

Vascular complication of trauma- Vascular complication of trauma- “Keinbock’s Disease”“Keinbock’s Disease”•• Keinbock’s disease = Avascular necrosis of lunateKeinbock’s disease = Avascular necrosis of lunate

•• Typical hx of trauma, either chronic repetitive or acute- Typical hx of trauma, either chronic repetitive or acute- fx not necessaryfx not necessary•• Inc. density and fragmentation of lunateInc. density and fragmentation of lunate

•• Presence of ulna minus variant predisposes to Presence of ulna minus variant predisposes to KeinbocksKeinbocks

Vascular complication- Keinbock’sVascular complication- Keinbock’s•• Increased radiopacity and beginning osteophyte formationIncreased radiopacity and beginning osteophyte formation

•• Predisposes to premature DJDPredisposes to premature DJD

Hand injuries – Bennett’s fxHand injuries – Bennett’s fx•• A fracture-subluxation of the first carpo-metacarpal A fracture-subluxation of the first carpo-metacarpal articulationarticulation•• Typically, an oblique fx thru the base of the 1Typically, an oblique fx thru the base of the 1stst MC base MC base

•• The 1The 1stst MC becomes unstable and displaces proximally MC becomes unstable and displaces proximally and into flexionand into flexion–– Usually internal fixation used to stablizeUsually internal fixation used to stablize

Hand injuries – Rolando fxHand injuries – Rolando fx•• A comminuted Bennett fracture; same mechanism and A comminuted Bennett fracture; same mechanism and management applymanagement apply

Hand injuries – Gamekeeper’s ThumbHand injuries – Gamekeeper’s Thumb•• Abduction force to the 1Abduction force to the 1stst MCP articulation causes avulsion of the MCP articulation causes avulsion of the base of the proximal phalanxbase of the proximal phalanx•• Ulnar collateral lig. may rupture without fracture = neg plain Ulnar collateral lig. may rupture without fracture = neg plain film!film!

Gamekeeper’s Thumb (ski-pole thumb)Gamekeeper’s Thumb (ski-pole thumb)•• Fragment is retracted a significant distance from the Fragment is retracted a significant distance from the injury in this caseinjury in this case

•• This injury may be acquired from skiing = “ski-pole This injury may be acquired from skiing = “ski-pole thumb”thumb”

Gamekeeper’s Thumb (ski-pole thumb)Gamekeeper’s Thumb (ski-pole thumb)Films below right and left thumbs of same patient- injuries Films below right and left thumbs of same patient- injuries

not acute at time of filmsnot acute at time of films

Hand injuries – Metacarpal fxHand injuries – Metacarpal fx•• Fractures of the distal (neck) portion are commonFractures of the distal (neck) portion are common–– “Bar room” or “boxer” fractures“Bar room” or “boxer” fractures

•• Palmar angulation commonPalmar angulation common–– More acceptable in neck portion of MC; not good in diaphysisMore acceptable in neck portion of MC; not good in diaphysis

•• If fingers overlap on flexion, then rotational malpostion inferred If fingers overlap on flexion, then rotational malpostion inferred –– Malrotation Malrotation notnot acceptable acceptable

Boxer FractureBoxer FractureHand injuries – Metacarpal fxHand injuries – Metacarpal fx•• Midshaft MC fracture with pin to avoid flexion deformityMidshaft MC fracture with pin to avoid flexion deformity

Injuries of the pelvisInjuries of the pelvis•• Pelvis is stable unless the pelvic ring is Pelvis is stable unless the pelvic ring is broken/separated in two placesbroken/separated in two places•• Stable injuries includeStable injuries include–– Avulsion fractures (see next slide)Avulsion fractures (see next slide)–– Isolated iliac wing fracture (not into pelvic opening)Isolated iliac wing fracture (not into pelvic opening)–– Single ramus fracture of obturator foramenSingle ramus fracture of obturator foramen–– Horizontal fracture of sacrumHorizontal fracture of sacrum–– Dislocation and/or fracture of coccyxDislocation and/or fracture of coccyx

•• Monitor sacral and coccygeal fracture for Monitor sacral and coccygeal fracture for neurological injuryneurological injury

Pelvic fracturePelvic fracture•• Anterior fractures acetabulum and pubic ramusAnterior fractures acetabulum and pubic ramus

•• Posterior fracutre is …….. Posterior fracutre is ……..

Pelvic fx diagragmPelvic fx diagragmAvulsion injuries of the pelvisAvulsion injuries of the pelvis•• Common sitesCommon sites–– ASIS – sartorius muscleASIS – sartorius muscle–– AIIS – rectus femoris muscleAIIS – rectus femoris muscle–– Ischial tuberosity – hamstring muscleIschial tuberosity – hamstring muscle

•• Stable injuries, typically managed conservativelyStable injuries, typically managed conservatively

Avulsion injuries of the pelvisAvulsion injuries of the pelvis•• Avulsions of AIIS (left) and ASIS (right)Avulsions of AIIS (left) and ASIS (right)

Avulsion injuries of the pelvisAvulsion injuries of the pelvis•• Old avulsions of ASIS Old avulsions of ASIS

Avulsion injuries of the pelvisAvulsion injuries of the pelvis

•• Avulsion of ischial tuberosityAvulsion of ischial tuberosity

Pubic SymphysisPubic Symphysis•• Diastasis may occur due to multiple childbirthDiastasis may occur due to multiple childbirth

•• Case below is 39 yr. old female with 10 children- note Case below is 39 yr. old female with 10 children- note the wide symphysis pubisthe wide symphysis pubis

Stress fracture of pelvisStress fracture of pelvis•• In osteoporotic patients who begin walking program, In osteoporotic patients who begin walking program, stress fracture may develop in pelvisstress fracture may develop in pelvis

Slipped Femoral Capital EpiphysisSlipped Femoral Capital Epiphysis•• Separation thru the proximal femoral physisSeparation thru the proximal femoral physis•• Easily overlooked! Easily overlooked! –– May present with “knee” (lower thigh) painMay present with “knee” (lower thigh) pain

•• Age: peak in late childhood/early adolescenceAge: peak in late childhood/early adolescence•• Sex: Males > Females approx. 2:1Sex: Males > Females approx. 2:1•• Left hip > right hip, but bilateral in 20-30%Left hip > right hip, but bilateral in 20-30%–– Females more commonly bilateralFemales more commonly bilateral

•• Avascular necrosis may occur as complicationAvascular necrosis may occur as complication

S F C E – x-rayS F C E – x-ray•• Blurring, irregularity of metaphyseal border of physeal Blurring, irregularity of metaphyseal border of physeal plateplate•• Widening of physisWidening of physis

•• Klein’s line does not intersect FCEKlein’s line does not intersect FCE–– Klein’s line along lateral femoral neck should intersect small Klein’s line along lateral femoral neck should intersect small portion of FCE on both AP and frogleg viewsportion of FCE on both AP and frogleg views

S F C E – x-rayS F C E – x-ray•• Apparent dec. height of FCEApparent dec. height of FCE–– Due to posterior, medial and inferior displacement of FCEDue to posterior, medial and inferior displacement of FCE

•• Loss of Capener’s triangle Loss of Capener’s triangle –– overlap of medial metaphyseal margin over acetabulumoverlap of medial metaphyseal margin over acetabulum

•• Decreased height of FCEDecreased height of FCE

SFCESFCEProximal femoral fracturesProximal femoral fractures•• TypesTypes–– intracapsularintracapsular–– extracapsularextracapsular

•• IntracapsularIntracapsular–– subcapital- most common typesubcapital- most common type–– mid-cervicalmid-cervical–– BasicervicalBasicervical

•• ExtracapsularExtracapsular–– intertrochantericintertrochanteric–– subtrochantericsubtrochanteric–– trochanterictrochanteric–– May be difficult to seeMay be difficult to see

When to x-ray? Ottowa RulesWhen to x-ray? Ottowa Rules

•• Investigators in Ottawa conducted a Investigators in Ottawa conducted a retrospective chart review of all patients with acute retrospective chart review of all patients with acute knee injuries who presented to an emergency knee injuries who presented to an emergency department over a 10-month department over a 10-month •• The knees of 74 percent of these patients were The knees of 74 percent of these patients were evaluated radiographically, but only 5.2 percent wereevaluated radiographically, but only 5.2 percent were found to have fractures.. found to have fractures.. When to x-ray? Ottowa RulesWhen to x-ray? Ottowa Rules•• AgeAge

•• gendergender

•• mechanism of injury mechanism of injury –– (blunt trauma or fall versus twisting)(blunt trauma or fall versus twisting)

•• EffusionEffusion

•• ligamentous instability, and pain on palpation. ligamentous instability, and pain on palpation.

•• history of swellinghistory of swelling

•• history of deformityhistory of deformity

•• ability to ambulate (i.e., to walk four steps)ability to ambulate (i.e., to walk four steps)

•• SwellingSwelling

•• decreased range of motiondecreased range of motion

Ottawa Rules- X-ray if….Ottawa Rules- X-ray if….•• Age 55 years or older with hx blunt traumaAge 55 years or older with hx blunt trauma

•• Tenderness at head of fibulaTenderness at head of fibula

•• Isolated tenderness of patellaIsolated tenderness of patella

•• Inability to flex knee to 90 degreesInability to flex knee to 90 degrees

•• Inability to walk four weight-bearing steps Inability to walk four weight-bearing steps immediately after the injury and in the emergency immediately after the injury and in the emergency

departmentdepartment Subsequent studies have shown these rules to be Subsequent studies have shown these rules to be

nearly 100% sensitive, but may show significant nearly 100% sensitive, but may show significant false positives.false positives.

•• Blunt trauma or a fall as mechanism of injury plus Blunt trauma or a fall as mechanism of injury plus either of the following:either of the following:

–– Age younger than 12 years or older than 50 yearsAge younger than 12 years or older than 50 years

–– Inability to walk four weight-bearing steps in the emergency Inability to walk four weight-bearing steps in the emergency department department

•• In a 1996 prospective study, the Pittsburgh decision rules In a 1996 prospective study, the Pittsburgh decision rules were 99 percent sensitive (were positive when fracture were 99 percent sensitive (were positive when fracture was present) and had a positive predictive value of 24% was present) and had a positive predictive value of 24% (fracture was present when positive findings present ). (fracture was present when positive findings present ). (JAMA 1996;275:611-5)(JAMA 1996;275:611-5)

Trauma- plain film findingsTrauma- plain film findings•• Tibial plateau fractures are most common of proximal tibial Tibial plateau fractures are most common of proximal tibial fracturesfractures•• Bone injuries often accompanied by cartilage/ligament injuryBone injuries often accompanied by cartilage/ligament injury

•• Varus/valgus stresses applied to knee result in compression forceVarus/valgus stresses applied to knee result in compression force to tibial plateau on one side with distraction force to ligaments on to tibial plateau on one side with distraction force to ligaments on contalateral sidecontalateral side

Trauma- plain film findingsTrauma- plain film findings•• Films (from Greenspan) show 30 yr. old alcoholic struck Films (from Greenspan) show 30 yr. old alcoholic struck by a car with a wedge fracture of the lateral tibial plateauby a car with a wedge fracture of the lateral tibial plateau•• Laterally applied force creates inferior vector on lateral Laterally applied force creates inferior vector on lateral tibial plateautibial plateau

Trauma- plain film findingsTrauma- plain film findingsThis series (also from Greenspan) shows depressed lateral This series (also from Greenspan) shows depressed lateral

plateau fx on 38 yr. old struck by a car.plateau fx on 38 yr. old struck by a car.Cross-table lateral shows the fat-blood interface resulting Cross-table lateral shows the fat-blood interface resulting

from intraarticular extension of fx.from intraarticular extension of fx.(FBI sign)(FBI sign)

Segond fractureSegond fracture•• Avulsion force to the insertion of the iliotibial band can Avulsion force to the insertion of the iliotibial band can result in detached fragmentresult in detached fragment

Segond fractureSegond fracture•• Avulsion force to the insertion of the iliotibial band can Avulsion force to the insertion of the iliotibial band can result in detached fragmentresult in detached fragment

Spine traumaSpine traumaCanadian C-rule for radiographyCanadian C-rule for radiography3 steps3 steps•• 11stst- Are there high risk factors that mandate x-ray?- Are there high risk factors that mandate x-ray?–– Age >/+65Age >/+65–– Dangerous* mechanismDangerous* mechanism–– Paraesthesia of limbsParaesthesia of limbs

•• *Dangerous mechanism*Dangerous mechanism–– Fall from </=1.5metersFall from </=1.5meters–– Axial compression to headAxial compression to head–– Hi speed (>100km) MVA, rollover or ejectionHi speed (>100km) MVA, rollover or ejection–– Mechanized recreation vehicleMechanized recreation vehicle–– Bicycle collisionBicycle collision

Canadian C-rule for radiographyCanadian C-rule for radiography

•• 22ndnd- Are there any low risk factors that allow ROM to be - Are there any low risk factors that allow ROM to be checked?checked?–– Simple rear-end MVA*Simple rear-end MVA*–– Sitting position in ERSitting position in ER–– Ambulatory at any timeAmbulatory at any time–– Delayed (ie, not immediate) onset of painDelayed (ie, not immediate) onset of pain–– Absence of midline neck painAbsence of midline neck pain

•• If If anyany of above present, then check ROM before x-ray of above present, then check ROM before x-ray

•• *Simple rear-end MVA excludes*Simple rear-end MVA excludes–– Pushed into oncoming trafficPushed into oncoming traffic–– Collision with large truck or busCollision with large truck or bus–– Hit by high speed vehicleHit by high speed vehicle–– RolloverRollover

Canadian C-rule for radiographyCanadian C-rule for radiography•• 3rd3rd- Check ROM- Check ROM–– If patient can actively rotate head/neck 45 to both right and left, If patient can actively rotate head/neck 45 to both right and left, then no x-ray recommendedthen no x-ray recommended–– If cannot demonstrate 45 degrees rotation to both right and left, If cannot demonstrate 45 degrees rotation to both right and left, x-ray recommendedx-ray recommended

•• Note- this study did not overlook “significant” injuries toNote- this study did not overlook “significant” injuries to cervical spine, however avulsion fractures and compression cervical spine, however avulsion fractures and compression injuries of <25% were not considered to be of significance injuries of <25% were not considered to be of significance for this study, since they are managed conservatively for this study, since they are managed conservatively

Spine trauma- stable vs unstableSpine trauma- stable vs unstable•• Stable = further limited motion unlikely to be Stable = further limited motion unlikely to be associated with significant neurological injury.associated with significant neurological injury.

•• Unstable = risk of neurological injury is high if further Unstable = risk of neurological injury is high if further motion is permitted.motion is permitted.•• Stable injuries C-spineStable injuries C-spine–– Post arch fx C1Post arch fx C1–– Simple wedge fxSimple wedge fx–– Unilateral facet dislocationUnilateral facet dislocation–– SubluxationSubluxation

•• Unstable injuries C-spineUnstable injuries C-spine–– Teardrop fx (flexion or extension type)Teardrop fx (flexion or extension type)–– Dens fxDens fx–– Burst (Jefferson) fx C1Burst (Jefferson) fx C1–– Hangman fx (C2 pedicles)Hangman fx (C2 pedicles)

–– Bilateral facet dislocationBilateral facet dislocation

AMA guidelines for loss of motion AMA guidelines for loss of motion segment integritysegment integrity•• Cervical spineCervical spine–– Motion segment demonstrates axial axis rotation (ie, Motion segment demonstrates axial axis rotation (ie, flex/ext) that is more than 11 degrees in excess of the flex/ext) that is more than 11 degrees in excess of the rotation of rotation of bothboth of the adjacent motion segments of the adjacent motion segments–– A-P translational displacement > 3.5mmA-P translational displacement > 3.5mm

•• Lumbar spineLumbar spine–– A-P translational displacement > 5mmA-P translational displacement > 5mm

3 columns of thoracolumbar spine3 columns of thoracolumbar spine•• Anterior columnAnterior column–– Anterior 2/3 of body and discAnterior 2/3 of body and disc

•• Middle columnMiddle column–– Posterior 1/3 of body and disc, including the PLL and annular discPosterior 1/3 of body and disc, including the PLL and annular disc fibersfibers

•• Posterior columnPosterior column–– Posterior elements (Zygopophyseal jnts and capsules, neural Posterior elements (Zygopophyseal jnts and capsules, neural arch, lig. flavum, infra- and supraspinous ligamentsarch, lig. flavum, infra- and supraspinous ligaments

Cervical spine traumaCervical spine trauma•• SOFT TISSUE SIGNS: SOFT TISSUE SIGNS:

•• Wide retropharyngeal space (should be <7mm Wide retropharyngeal space (should be <7mm at C2 level) at C2 level) •• Displaced prevertebral fat stripe Displaced prevertebral fat stripe •• Tracheal deviation a/o laryngeal dislocation Tracheal deviation a/o laryngeal dislocation •• Wide retrotracheal space- normals should be:Wide retrotracheal space- normals should be:–– < 23 mm at C6 level for adult< 23 mm at C6 level for adult–– < 14 mm at C6 level for child< 14 mm at C6 level for child

C-spine: injury vs mechanismC-spine: injury vs mechanism•• HYPEREXTENSION HYPEREXTENSION

–– Hyperextension Hyperextension dislocation Hyperextension Hyperextension dislocation –– Avulsion fx of the anterior arch of atlas Avulsion fx of the anterior arch of atlas –– Extension teardrop fracture of the axis Extension teardrop fracture of the axis –– Fracture of the posterior arch of atlas Fracture of the posterior arch of atlas –– Laminar fracture Laminar fracture

•• Traumatic spondylolisthsis (Hangman's fracture) Traumatic spondylolisthsis (Hangman's fracture) –– A fractureA fracture--dislocation type injurydislocation type injury •• LATERAL FLEXION LATERAL FLEXION –– Uncinate process fractureUncinate process fracture

C-spine: injury vs mechanismC-spine: injury vs mechanism•• HYPERFLEXION HYPERFLEXION –– Anterior subluxation (hyperflexion sprain) Anterior subluxation (hyperflexion sprain) –– Bilateral interfacetal dislocation Bilateral interfacetal dislocation –– Simple wedge compression fracture Simple wedge compression fracture –– Clay shoveler's fracture Clay shoveler's fracture –– Flexion teardrop fracture Flexion teardrop fracture

•• SIMULTANEOUS HYPERFLEXION AND ROTATION SIMULTANEOUS HYPERFLEXION AND ROTATION –– Unilateral interfacetal dislocation (locked vertebraUnilateral interfacetal dislocation (locked vertebra) )

•• SIMULTANEOUS HYPEREXTENSION AND ROTATION SIMULTANEOUS HYPEREXTENSION AND ROTATION –– Pillar fracture Pillar fracture

•• VERTICAL COMPRESSION VERTICAL COMPRESSION –– Jefferson bursting fracture Jefferson bursting fracture –– Burst fracture Burst fracture

•• INJURIES CAUSED BY DIVERSE OR IMPRECISELY INJURIES CAUSED BY DIVERSE OR IMPRECISELY UNDERSTOOD MECHANISMS UNDERSTOOD MECHANISMS –– AtlantoAtlanto--occipital dissociation (ext/flex) occipital dissociation (ext/flex) –– Odontoid fractures Odontoid fractures

ABNORMAL VERTEBRAL ALIGNMENTABNORMAL VERTEBRAL ALIGNMENT •• Loss of lordosis secondary to m. spasmLoss of lordosis secondary to m. spasm

•• Acute kyphotic angulation Acute kyphotic angulation –– May be related to rupture of nuchal, interspinous and or May be related to rupture of nuchal, interspinous and or capsular ligaments capsular ligaments

•• Traumatic torticollis Traumatic torticollis

•• Widened interspinous spaces Widened interspinous spaces

•• George's line abnormal George's line abnormal

•• Vertebral body rotation Vertebral body rotation –– M. spasm may causeM. spasm may cause–– Unilat. facet dislocat'n may causeUnilat. facet dislocat'n may cause–– Hyperext./flex. # dislocation may cause Hyperext./flex. # dislocation may cause

•• Atlantodental interspace widening Atlantodental interspace widening >3mm for adult >3mm for adult > 5mm for child > 5mm for child

•• Lateral mass overhangLateral mass overhang–– 1-2mm OK for infants1-2mm OK for infants–– >6.9mm combined = t>6.9mm combined = t’’verse lig rupturedverse lig ruptured

ABNORMAL JOINTSABNORMAL JOINTS

–– Widened apophyseal jointsWidened apophyseal joints –– Widened Atlantoaxial jointsWidened Atlantoaxial joints –– Abnormal discAbnormal disc –– LUCENT CLEFT SIGNLUCENT CLEFT SIGN •• May only be visible on the extension projectionMay only be visible on the extension projection

•• Difficult to d/dx from degenerative vacuum phenomenonDifficult to d/dx from degenerative vacuum phenomenon

DISTRIBUTION OF CERVICAL SPINE INJURIESDISTRIBUTION OF CERVICAL SPINE INJURIES

•• C1 C1 -- 6% 6%

•• C2 C2 -- 27% 27%

•• C3 C3 -- 10% 10%

•• C4 C4 -- 10% 10%

•• C5 C5 -- 18% C7 18% C7 -- 18% 18%

•• C6 C6 -- 27% 27%

JEFFERSON FRACTURE JEFFERSON FRACTURE –– Bilateral fractures thru the anterior and posterior neuralBilateral fractures thru the anterior and posterior neural

ring of atlas ring of atlas –– May be associated with lateral displacement of the May be associated with lateral displacement of the

lateral masses and transverse ligament disruption. lateral masses and transverse ligament disruption. –– Results from compression force Results from compression force –– Low incidence of neurological injury Low incidence of neurological injury –– Usually treated with conservative immobilization. Usually treated with conservative immobilization.

–– Look for combined overlap Look for combined overlap >/= >/= 7mm; indicates t'verse 7mm; indicates t'verse lig. rupture. lig. rupture.

–– Associated spine #’s in 24-48%- check other areas Associated spine #’s in 24-48%- check other areas carefully!carefully!

•• Normal alignment of C1-2 on APOM- no significant Normal alignment of C1-2 on APOM- no significant overhang of lateral masses relative to C-2 facet marginoverhang of lateral masses relative to C-2 facet margin

JEFFERSON FRACTUREJEFFERSON FRACTUREC-1 posterior arch fractureC-1 posterior arch fracture•• Hyperextension traps thin C-1 arch between occiput Hyperextension traps thin C-1 arch between occiput and large posterior arch C-2and large posterior arch C-2•• Usually stable injuryUsually stable injury

Atlanto-occipital dissociationAtlanto-occipital dissociation•• Not common- less than 1% of all acute c-spine injuriesNot common- less than 1% of all acute c-spine injuries

•• Commonly with neurological deficit or fatalCommonly with neurological deficit or fatal

•• Powers ratio Powers ratio –– Line from basion to junction line of C1 posterior arch = BCLine from basion to junction line of C1 posterior arch = BC–– Line from opisthion to anterior arch C1 (posterior cortex) = AOLine from opisthion to anterior arch C1 (posterior cortex) = AO–– BC/AO should not be greater than 1.15BC/AO should not be greater than 1.15

C-2 fracture- “Hangman” typeC-2 fracture- “Hangman” type•• Bilateral fracture thru pedicles Bilateral fracture thru pedicles

•• More likely flexion-type injury; maybe extensionMore likely flexion-type injury; maybe extension

C-2 fracture- “Hangman” typeC-2 fracture- “Hangman” type•• CT imaging shows fracture and “perched” facets C2/3CT imaging shows fracture and “perched” facets C2/3

Columns of the spineColumns of the spine•• Anterior column is ALL, anterior 2/3 vertebral body and anterior Anterior column is ALL, anterior 2/3 vertebral body and anterior ½ of IVD½ of IVD•• Middle column is posterior 1/3 body, back to and including the Middle column is posterior 1/3 body, back to and including the PLLPLL•• Posterior column is posterior arch and ligamentsPosterior column is posterior arch and ligaments

•• Single column injury is usually stableSingle column injury is usually stable

•• Two column injury is usually unstableTwo column injury is usually unstable

•• Three column injury is unstableThree column injury is unstable