Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 2007_08_23-Patterson-Lower_limb_radiology
Transcript
Lower extremity xray rounds Heather Patterson PGY3 August 23, 2007 Objectives • Classification of fractures • Practice, practice, practice! • This will NOT be: – Clinical exam – Management Hip • Classification: – Intracapsular • Femoral head • neck – Extracapsular • Intertrochanteric • Subtrochanteric • Greater/lesser trochanter Hip • AVN: – Injuries to medal and lateral femoral circumflex arteries – After fracture the synovial fluid will lyse blood clots and prevent capillary formation needed for new bone formation/repair Approach • Shenton’s Line – Obturator foramen to medial surface of the proximal femur Approach • Normal and Reverse S – Medial and lateral margins of the fem head and neck Approach • Trabecular groups – Follow the groups starting at the femoral head Avulsion • Often in young athletes • Rapid accel/decel • Snap/pop • Locations: – ASIS: sartorius – AIIS: rectus femoris – Isch tuberosity: hamstring Name this fracture Femoral Neck Fractures • Classification: – Transcervical vs subcapital – Displaced vs nondisplaced Femoral Neck Fractures • Displaced (80%) – Shortened, rotated – Vascular structures disrupted • Nondisplaced (20%) – Subtle fractures • Must use lines/trabec to see • May be impacted – increased subcapital density Name this fracture Intertrochanteric fractures • Fracture runs between greater and lesser trochanter • Excellent blood supply • Often will be in internal rotation – Int rotators attached to distal femur – Ext rotators attached to proximal fragment Intertrochanteric fractures • Classification: – 2 part Intertrochanteric fractures • Classification – 3 part: Intertrochanteric fractures • Classification – 4 part: Trochanter fractures • Isolated fractures are rare • From direct force with fall or avulsion from iliopsoas Name this fracture Subtrochanteric fractures • Location: – Btwn lesser trochanter and proximal 5cm of femoral shaft – Often comminuted – Hemodynamic instability is seen with this fracture type Subtrochanteric fractures • Classification: – – – – – – Short oblique Short oblique + commin. Long oblique Long oblique + commin. High transverse Low transverse Stress fractures • Need high index of suspicion • Symptoms: – A.M. stiffness, aching with first steps after rest, increasing pain with exercise – Pain in groin or medial thigh to knee – Antalgic gait, min pain with ROM except at extremes Dislocations • High force • Classification: – – – – – Posterior Anterior Obturator Inferior Central Fracture dislocations • Positioning: – Posterior: FDI • flexed aDducted internal rotation • shortened and greater troch/buttock unusually prominent – Anterior: FBE • flexed aBducted, externally rotated Dislocations • Posterior: – Lesser trochanter superimposed on femoral shaft – Small femoral head Dislocations • Anterior: – Lesser trochanter in profile – Large femoral head Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise Name this fracture Ottawa Knee rules • X-ray knees with knee injury and one or more of: – – – – – >55 years old Tenderness to palpation of head of fibula Isolated tenderness of patella Inability to flex knee to 90 degrees Inability to bear weight both immediately and inability to take four steps in ED Ottawa Knee rules • Exclusion criteria: – – – – – – – – – Isolated skin injuries Referred patients from another ED or clinic Injury >7 days old Patient returning for re-evaluation Distracting injuries Altered mental status Age < 18 years old Pregnant patients Paraplegia Distal femur fracture • Anatomy: – Vascular • close to femoral & popliteal vessels Distal femur fracture • Anatomy: – Neuro • Tibial nerve – gastrocnemius, plantaris • Peroneal/Deep Peroneal nerves – Supplies anterior compartment (dorsiflexion) – Sensory to first dorsal interosseus cleft Distal femur fracture Distal femur fracture • Supracondylar – Extra-articular – No hemarthrosis • Intracondylar – Intra-articular • Condylar – Intra-articular Name this fracture Tibial Plateau Fractures • Anatomy – Vascular • High incidence of popliteal A damage – Neuro • Perineal N damage – Ligaments • 25% have associated ligamentous injury Tibial Plateau Fractures • Plateau slopes 10 degrees from A P – May not appear to be at same level • Lateral plateau slightly convex upward • Medial plateau slightly concave upwards Schatzker Classification Schatzker Classification • Type IV (15%): – Medial plateau • Type V: – Bicondylar Schatzker Classification • Type VI: – Bicondylar and tibial shaft Tibial Plateau Fractures • Occult fracture: – Lateral may show lipohemarthrosis Name this fracture Segond • Segond fracture: – Avulsion of lateral plateau at site of insertion of lateral capsular lig – Marker for ACL disruption and anterolateral rotary instability Name this fracture Tibial Spine Fractures • Type I – Incomplete avulsion with no displacement • Type II – incomplete avulsion with displacement • Type III – Completely avulsed fragment Tibial Spine Fractures • Don’t forget the TUNNEL views Name this fracture Tibial Tuberosity Fractures • Type I – Distal fragment displaced proximally and anteriorly • Type II – Fragments hinged at proximal portion – Large fragment extending into physis Tibial Tuberosity Fractures • Type III – Extension into articular surface Name this fracture? Patellar Fracture • Classification: – Transverse, vertical, stellate/comminuted, marginal, osteochondral avulsion – Proximal or distal pole – Displaced or nondisplaced Patellar Fracture • Radiology: – AP – Lateral – Sunrise • Tangential view across 45 degree flexed knee • Shows small vertical fractures of patella Patellar Fracture • What about this? Patellar Fracture • Sharp, nonsclerotic margins = acute fracture • Smoother, sclerotic margins = non acute Patellar tendon rupture • What about this pt? – sudden onset of pain when playing football. Patellar tendon rupture • Radiology: – Patella alta • Ratio of patellar tendon length to patella • >1:2 is abnormal – Poorly defined soft tissue mass • Retracted tendon – +/- soft tissue calcific densities • Avulsed bone fragments Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise • Practise Practise Practise Practise Practise Practise Practise Practise Practise Practise Ankle Fractures • Anatomy • Ankle Rules • Classification • Practice BONES Fibula Tibia Talus LIGAMENTS Syndesmotic Ligaments Medial Collateral Ligaments Lateral Collateral Ligaments Ankle Fractures • Ring structure • Disruption of >1 part = unstable Ottawa Ankle Rules – Age 55 or older – Inability to weight bear both immediately and in ER (4 steps) – Bony tenderness over posterior distal 6 cm of lateral or medial malleoli • Sensitivity ~100% • Specificity ~40% Xray views • AP – Fractures of: • Malleoli • Distal tibia/fibula • Plafond • Talar dome, body and lateral process • Calcaneous Xray views Xray views Xray views • Mortise – Ankle 15-25 degrees internal rotation – Evaluates articular surface between talar dome and mortise Mortise view Mortise view • Medial clear space – Between lateral border of medial malleous and medial talus – <4mm is normal – >4mm suggests lateral shift of talus • Tibfib clear space – <5mm Mortise views • Talar tilt – Normal = -1.5 to +1.5 degrees (ie. Parallel) – Can go up to 5 degrees in stress views – <2mm difference between medial and lateral talar/plafond distances Xray views • Lateral – Fractures of: • anterior/posterior tibial margins – Talar neck – Displacement/ dislocation of talus Weber Classification •Weber A= below tibiotalar joint – No disruption of syndesmosis •A1: – Lat maleolus only •A2: – Lat maleolus plus deltoid tenderness/medial mal # •A3: – Lat maleolus plus posterior mal # Weber Classification •Weber B = at level of tibiotalar joint – Partial disruption of syndesmosis Weber Classification •Weber C= above tibiotalar joint – Disrupts syndesmosis – Unstable Pott’s Classification • Unimaleolar • Bimaleolar • Trimaleolar Pott’s Classification • Unimaleolar – Lat maleolus: use Weber classification – Medial maleolus: rarely in isolation • Watch for Maisonneuve – Post maleolus: rarely in isolation Pott’s Classification • Bimaleolar – Unstable – Often have associated syndesmosis injury • Trimaleolar – Unstable Name this fracture Maisonneuve • Medial maleolar fracture/lig disruption plus proximal fibular fracture • Syndesmosis injury Name this fracture Pilon • Fracture of distal tibial metaphysis • High energy mechanism • Association with other injuries – Calcaneous, tib plateau, fem neck, pelvis, spine, abdo • Multiple complication and poor outcomes Examples… Examples… Examples… Examples… Examples… Examples… Examples… Examples… Examples… Examples… Examples… Examples… What if this patient was tender over the deltoid ligament? Examples… Examples… Examples… High Ankle Sprain • Also known as a syndesmosis ankle sprain • May include injury to : – distal anterior inferior tibiofibular ligament (AITFL) – Posterior inferior tibiofibular ligament (PITFL) – Distal interosseous ligament (IOL) • Prolonged recovery High Ankle Sprain • Exam: – Pain over syndesmosis – Pain with external rotation – Squeeze test High Ankle Sprain • Radiology: – Ankle views if significantly tender – Stress views not recommended acutely • No change in management High Ankle Sprain • Type 1-2 – PRICE therapy – Early ambulation – Physio/Sports med to follow • Type 3 (rupture) – Ortho to see – ORIF Name this abnormality Approach to Radiographs Lisfranc - approach 1. Fracture: • 2nd metatarsal base: – evaluate for fracture, avulsions and displacement *** fracture of proximal 2nd MT is indicative of a Lisfranc injury Thanks Marc Approach to Radiographs Lisfranc - approach 2. Straight lines: On AP and Oblique films – medial aspect of the 2nd MT base and the middle cuneiform Thanks Marc Approach to Radiographs Lisfranc - approach 2. Straight lines: – Medial border of the 4th MT base and the cuboid – Lateral border of the base of 3rd MT with lateral border of the 3rd cuneiform Thanks Marc Approach to Radiographs Lisfranc - approach 3. “fleck sign” • Small avulsed fragments indicate ligamentous injury and joint disruption Thanks Marc Approach to Radiographs Lisfranc – approach 4. “Step-off” On lateral films – No metatarsal shaft should be more dorsal than it’s respective tarsal bone Thanks Marc Approach to Radiographs Lisfranc - approach 5. Separation: • base of the 1st and 2nd MT • 1st and 2nd cuneiforms ***strongly suggestive of a subluxation Thanks Marc 6. Fracture: • Cuboid • Cuneiforms • Navicular • MT shafts ***suggestive of Lisfranc 2 types of Lisfranc injuries Lisfranc - Classification • Homolateral type: – • Lateral displacement of the 1st through 5th MT heads Divergent type: – Thanks Marc The 1st (and occasionally the 2nd) MT dislocates medially or stays fixed, while the more lateral metatarsals are displaced laterally Practice Practice A little bit of extra info…. • Xray presentation with calcaneus, talus, navicular fractures Anatomy Anatomy Case • 35M working on roof, falls, lands like a cat • c/o bilat heel pain and back pain Case Case Calcaneus Fracture Calcaneus fractures Posterior tuberosity apex of anterior process apex of posterior facet Calcaneus Fracture • Mechanism: – High energy axial load • Intra or extraarticular • Associations: – 7% bilateral – 10% spine compression # – 25% other LE injury Calcaneus Fracture • Imaging: – Standard AP/Lat foot and ankle views – Axial – +/- CT • Important distinctions: – Involvement of subtalar joint – Depression of posterior facet Calcaneus Fracture • Ortho: – Treatment patterns vary – Intraarticular and comminuted fractures must be seen • Outcomes: – Poor outcomes – >50% have loss of ROM, chronic pain, and functional disability Case • 32M fell and landed with pointed toes Case Talar fractures • Anatomy: – 7 articular surfaces (60% of surface) – Regions: • Body • Neck • Head Talar fractures • Minor talar fractures: – HEAD AND NECK: • Avulsion and chip fractures of superior surface – BODY: • Lateral, medial, posterior body AND osteochondral of talar dome • Require immobilization and referral to ortho for f/u Talar fractures • Talar neck fractures – 50% of major talar injuries. – Mechanism: • extreme dorsiflexion – Hawkins classification – Often associated fractures Talar fractures • • • • Type 1: nondisplaced Type 2: subtalar subluxation Type 3: dislocation of the talar body (50% open #’s) Type 4: dislocation of the talar body & distraction of the talonavicular joint. Fracture type influences management & prognosis Talar fractures • Talar body fractures – 23% of all talar fractures • Ie posterior or lateral process fracture – Major talar body fractures are uncommon • usually axial loading Talar fractures • Talar head fractures – Uncommon (5-10%) – Compression transmitted through the talonavicular joint applied on a plantarflexed foot Talar fractures • Management: – Major fractures require ortho consult • Outcomes: – Risk of AVN, OA, and chronic pain Case • 18F playing soccer, tripped and twisted foot • Not sure of how she twisted/landed Case Navicular Fracture • Classification: – Dorsal avulsion • >50% of navicular #s • Eversion injury • Associated with deltoid ligament injury • Minimal articular involvement – Tuberosity Fracture • Eversion injury • Associated with posterior tibialis tendon avulsion Navicular Fracture • Classification: – Body Fracture • Rare • Axial loading • Comminuted, intraarticular Navicular Fracture • Clinical – Pain on palpation – +/- pain on passive eversion or active inversion • Imaging – Standard foot views – +/- bone scan Navicular Fracture • Why do we care? – Significant risk of AVN • Management: – Outpatient Ortho: • Dorsal avulsion and tuberosity # with minimal articular involvement • Immobilize 4-6 wks – ED Ortho consult • Body#, displaced #, >20% of articular surface involved Practice…. Practice… Practice… Practice…. Practice…. Practice…. Practice…. Practice…. Practice…. Practice…. Practice…. Practice…. Practice….
