Radiologic Pitfalls. Objectives: High Risk! Occult Fracture? 2/16/2014

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1 Objectives: Radiologic Pitfalls Gregory W. Hendey, MD, FACEP Professor of Clinical Emergency Medicine UCSF Fresno, Medical Education Program To discuss plain film and physical findings that suggest an occult fracture To recognize clinical scenarios that are high risk for an occult fracture To discuss the evidence-based approach to evaluating patients for an occult fracture in order to avoid pitfalls High Risk! Kachalla, Annals of EM, 2007: 122 ED malpractice claims, 4 insurers Most common Missed Dx #1-Fracture, #2-Infxn, #3-MI Most common Errors: Failure to order right test (58%) Radiologic study (61%): #1-Xray Misinterpretation of test (37%) Radiologic study (66%): #1-Xray Occult Fracture? Not readily visible on plain radiographs, using standard techniques Clinically important Change in management Significant risk of complications if missed Missed Fracture = most common source of malpractice lawsuits in EM 1

2 Four common radiologic pitfalls: Ankle and Foot Hip Elbow Wrist THE ANKLE AND FOOT 2

3 When should I consider CT? 1) High clinical suspicion Mechanism, exam 2) Persistent pain/effusion at follow up Haapamaki, Am J Roentgenol, 2004: Retro, 344 pts with fx on Ankle/foot CT Pts with Fx not visualized on plain films: Calcaneus (20) Talus (15) Calcaneus fracture Bohler s angle 3

4 Bohler s angle Harris Calcaneal view CT scan: Occult fracture Plan surgery Talar dome fracture Osteochondral lesion CT or MRI Non-wt bearing vs Arthroscopy 4

5 Avoiding Pitfalls (ankle/foot): Fracture of the Lateral process of the Talus Snowboarding Axial load in dorsiflexion, external rotation Surgical repair CT scan of the ankle: High suspicion Mechanism Exam Poor recovery on follow up exam Case: THE HIP 75 year old woman has fallen and she can t get up Pain in left hip with attempts to bear weight No deformity or other injury 5

6 Shenton s Line What next? a) Hip contusion d/c home b) CT scan c) MRI d) Sign out to next doc MRI vs CT Lubovsky, Injury, 2005: 13 pts with suspected fx, negative Xrays 6 had both MRI and CT (slice?) CT incorrect in four (under-dx) CT: Gr. Trochanteric fx MR: 3 Intertroch fx, 1 subcapital fx 6

7 Hakkarinen, JEM, 2012: Case series, 235 hip fx 211 (90%) visible on plain films 24 occult fx 18 identified by CT (MRI not done) 4 had Neg CT, positive MRI 82 yo F Fell on L hip Plain films negative: CT: MRI: 7

8 Avoiding Pitfalls (hip): MRI still the gold standard for excluding occult hip fracture THE ELBOW Is CT useful at all? If positive Younger trauma patients Low clinical suspicion Occult fractures Adult Radial head Pediatric Supracondylar 8

9 90 degree lateral 1) Fat pads Bulging anterior Posterior 2) Radio-capitellar line Adult Elbow 3) Anterior Humeral Line Pediatric Elbow Anterior Humeral Line Avoiding Pitfalls (elbow): Look for fat pads Draw the lines 9

10 Case: 31 yo M struck by martial arts instructor c/o wrist pain Snuffbox tenderness 10

11 Scaphoid fracture Most common carpal fracture 10-20% occult Distal blood supply Proximal fx worse Delayed complications: Non-union Avascular necrosis AVN, non-union Frequent occult fractures + Frequent complications = Thumb spica splint and follow-up MRI vs CT: Memarsadeghi, Radiology, 2006: 29 pts, neg X-ray, had CT (4) and MRI Gold std: plain films at 6 wks 11 scaphoid fx MR found 100%, CT found 8/11 (73%) 11

12 MRI vs CT: Ilica A, Japanese Journal of Radiology, 2012: 54 patients, snuffbox tenderness, Xray neg MRI and 64 slice CT within 1 week MRI 22 fractures (14 scaphoid) CT 19 fractures (12 scaphoid) Sensitivity of CT for occult scaphoid fx--86% Avoiding Pitfalls (scaphoid): Splint and follow-up versus Early MRI Summary: Clinical situations that suggest an occult fracture Evidence-based approach to evaluating patients for an occult fracture, to avoid radiologic pitfalls Thank you! Fair Use Notice: This presentation and syllabus may contain copyrighted material the use of which has not always been specifically authorized by the copyright owner. It is being made available in an effort to advance the understanding of medical, scientific, and other issues. It is believed that this constitutes a 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. 12