Radiology Together Emergency Radiology Conference SOFIA June, 2017
Common pitfalls and mistakes in lower extremity trauma
IGOR BORIĆ
„St. Catherine” Orthopedic Hospital, Zagreb, CROATIA Croatian Olympic Committee Diagnostic pitfalls
• Radiography remains the initial modality to detect or exclude the presence of a fracture.
• Failure to recognize lower extremities fractures - are the second most frequently missed diagnosis (after breast cancer)
• Radiologist errors - lead to failure or delay in diagnosis
Whang JS i sur. Radiology 2012 Diagnostic pitfalls
THE RADIOLOGIST NEVER MAKES A MISTAKE !!! Diagnostic pitfalls
• In a recent study of 3081 confirmed fractures in ED patients:
– 115 - initialy missed – 53% in the lower extremities – foot being the most missed location
– 37% - subtle fractures – 33% - radiographically occult fractures
Van Rijin i sur. J Trauma Actute Care Surg 2012 Wei CJ i sur. Acta Radiol 2006 Reasons for pitfalls
• RADIOLOGICAL - perceptual errors that appear to be avoidable (retrospectivly aproved)
• NON-RADIOLOGICAL - out of the interpreting radiologist’s control related to:
• anatomic • technical • physiologic factors Radiological pitfalls
• insufficient views
• improperly positioned or technically imperfect radiographs • nondisplaced fractures
• small avulsions portending large injury
• sesamoid injuries
• commonly missed locations
• satisfaction of search • periprosthetic fractures Insufficient views
• Fractures visible on only a single view
• Additional projections are required – orthogonal views in frontal and lateral projections for the long bones – Weight-bearing view: Lisfranc/Chopart joint injuries – stress view to show injury to the ankle mortise or syndesmotic diastasis – Axial patellar view
• Additional methods are required: CT/MRI
Fractures were not visible on lateral and anteroposterior radiographs. Middle cuboid fracture was not visible on standard radiographs. Sunrise view shows multiple avulsion fragments along medial margin Weight-bearing view shows fracture of the middle cuboid bone of patella. Improperly positioned or technically imperfect radiographs
• the best chance of seeing frx on radiographs is with multiple views that are properly positioned and technically adequate
• insufficient tube current (milliamperes) – an underexposed radiograph
Digital radiography – properly exposed radiograph
- control: gray scale, contrast and britness - image compression - use of substandard or handheld displays
Initial oblique radiograph does not show metatarsal fractures because of underpenetration and improper tube angulation. Nondisplaced fractures
• Simptomatic - the appropriate clinical findings and mechanism of injury (proximal femur frx in eldery after a groundlevel fall - the inability to bear weight)
• The radiographic findings are falsely negative, because the method itself is insufficient to reveal the fracture
• Osteoporosis: diffuse loss of bone mineral makes nondisplaced fracture lines less clear
– Additional imaging: CT – MR – radionuclide bone scan - US (if the clinical suspicion is high) Small avulsions portending large injury
• Small avulsion fractures - easy to overlook • Small avulsion fractures - portend major injuries
• Avulsion fractures – need for analysis of the associated soft-tissues
• Mechanism of injury analysis
Minimally displaced posterior malleolar fracture Acute Segond fracture at lateral tibial plateau is indicative of rupture of ankle syndesmosis. is indicative of ALC rupture. Bipartite sesamoid versus fracture
• a unique challenge for the radiologist
• Sesamoid bones – Often multipartite – Follow the clinical pictures – Sesamoid injury: stress reaction or fractures in runners
• Accessory ossicles – The ankle – „hot spot” – Can be fractured
Bipartite medial sesamoid with separation extending diagonally across bone. Transverse avulsion fracture at proximal aspect of the sesamoid. Satisfaction of Search
• „Satisfaction of search” - when the detection of one abnormality somehow interferes with the recognition of others
• Keep on mined common location for fractured
Initial evaluation standard radiographs of foot focused on multiple metatarsal and toe fractures and multiple metatarsophalangeal joint dislocations. Calcaneal fractures were initially overlooked. Fractures after hardware placement
• fracture fixation or joint replacement
• Hardware implants alter the stresses on the host bone: resulting in chronic bone loss where stress- shielding occurs and bony hypertrophy where stresses are concentrated. • Fractures begin at the interface between implant and bone
• Dense overlapping metallic densities can limit visualization of hardware fractures or periprosthetic bone fractures Commonly missed fractures
D O H Dislocation, Occult fracture, Half of injuries missed D O H – Dislocation, Occult fracture, Half of injuries missed
Location „Dislocation” „Occult fracture” „Half of injuries missed”
HIP Hip dislocation Femoral neck Another ring fracture Acetabulum sacrum KNEE PF dislocation Tibial platou Proximal fibula with ankle dislocation (Maisonneuve) ANKLE AND Lisfranc injury Kalkaneus Toracolumbar + calcaneus FOOT Talus frx. Hip
„Dislocation” „Occult fracture” „Occult fracture”
Hip dislocation Femoral neck Acetabulum
Most commonly Most commonly Anterior acetabular fracture: posterior missed hip fracture - break in iliopubic line Posterior acetabular fracture: CP: leg is shortened and X-ray: - break in the ilioischial line internally/externally - Can be very subtle rotated - Cortical disruption or Additional Imaging: CT: impacted hyperlucency - X-ray – Judet projection - for associated femoral - Loss of smooth cortical head / transition from femoral - CT acetabular fx’s neck to head. –for intraarticular bone - Trabecular disruption fragments CT - MRI Hip
„Dislocation” „Occult fracture” „Half of injuries missed”
Hip dislocation Femoral neck Another ring fracture
Most commonly Most commonly Because of the inflexible posterior missed hip fracture pelvic bone, injuries are often CP: leg is shortened and X-ray: found in multiples internally/externally - Can be very subtle rotated - Cortical disruption or X-ray : CT: impacted hyperlucency - subtle rami frx - for associated femoral - Loss of smooth cortical - Cortical/trabecular head / transition from femoral break acetabular fx’s neck to head. - Trabecular impaction –for intraarticular bone - Trabecular disruption fragments CT - MR CT - MRI Knee
„Dislocation” „Occult fracture” „Occult fracture”
Knee dislocation Tibial plateau „SEGOND” fractura
32% of all knee fractures Valgus stress with axial proximal lateral tibial avulsion fx load Not a subtle clinical or radiographic finding Often associated with an ACL
X-ray: tear
patient with knee pain from Requires angiography: blunt trauma can not walk – 40% have associated oblique views CT – MRI (ligaments) popliteal artery injury
CT – to assess for severity Knee
„Occult fracture” „Occult fracture” „Occult fracture”
Patella fracture Tibial plateau „SEGOND” fracture
32% of all knee fractures 40% of all knee Valgus stress with axial proximal lateral tibial avulsion fx fractures load
Often associated with an ACL tear Additional Imaging: X-ray:
“Sunrise” view (axial) patient with knee pain from blunt trauma can not walk – oblique views CT – MRI (ligaments)
CT – to assess for severity Knee
„Occult fracture” „Occult fracture” „Half of injuries missed”
Patella fracture Tibial plateau „MAISONNEUVE” fracture
32% of all knee fractures 40% of all knee Valgus stress with axial Proximal fibula fracture fractures load AND medial malleolus (or deltoid ligament) fracture
Additional Imaging: X-ray: Mechanism: Abduction “Sunrise” view (axial) patient with knee pain from and external rotation of blunt trauma can not walk – ankle oblique views
CT – MRI (ligaments) CT – to assess for severity Ankle and foot
„Dislocation” „Occult fracture” „Occult fracture”
„Lisfranc” injury Calcaneus fracture Talus fracture Most commonly Tarsal-metatarsal fracture/ fractured tarsal bone Second most commonly dislocation pattern fracture tarsal bone- talar neck Mechanism: 20% are initially missed Often from fall on heels Mechanism: Excessive Xray: Fracture of 2nd from a height dorsiflexion of ankle metatarsal base or Lisfranc ligament and subsequent X- ray: Xray: Can be subtle cortical dislocation of MT #2-5 - Bohler’s angle < 20 break on lateral view from the midfoot Complications: Additional Imaging: AVN, MRI: evaluation of - “calcaneal view” ligaments subchondral collapse, and OA CT/MR - fragments
Ankle and foot
„Dislocation” „Occult fracture” „Half of injuries missed”
„Lisfranc” injury Calcaneus fracture „Jumper’s/lover’s frx” calcaneus fracture Najčešća fraktura Tarzometatarzalna and TH/L spine tarzusa fraktura/dislokacija fracture
Obično posljedica 20% su inicijalno 10% associated with pada na petu THORACOLUMBAR previđene FRACTURE
Rtg: Rtg: fraktura baze 2. Bohler-ov kut >20° because of load on axial MT ili Lisfrancoog lig.i skeleton when landing on the dislokacija 2-5 MT heels CT - fragmenti
MR – rtg. nejasni MR: procjena ligamenata „Take home”
• Most undetected fractures - a perceptual errors (in a complex anatomy area)
• APROACH – Systematic Approach: ABC’S – Adequacy alignment, bones (fractures), cartilage (joint spaces), soft tissue signs - all views included and properly performed – Targeted Approach – analyze the radiographs for common sites of injury
• Corelation with clinical findings: (PACS, teleradiology) • Supplementary or delayed views • Additional methodes: CT/MR • Pseudo‐fractures – Radiographic variants that mimic fractures Thank you!