Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Section 2 Spine
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Section 7 Musculoskeletal
- Case 78 Pseudofracture from motion artifact
- Case 79 Mach effect
- Case 80 Foreign bodies not visible on radiographs
- Case 81 Accessory ossicles
- Case 82 Fat pad interpretation
- Case 83 Posterior shoulder dislocation
- Case 84 Easily missed fractures in thoracic trauma
- Case 85 Sesamoids and bipartite patella
- Case 86 Subtle knee fractures
- Case 87 Lateral condylar notch sign
- Case 88 Easily missed fractures of the foot and ankle
- Section 8 Pediatrics
- Index
- References
Case 81 - Accessory ossicles
from Section 7 - Musculoskeletal
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Section 2 Spine
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Section 7 Musculoskeletal
- Case 78 Pseudofracture from motion artifact
- Case 79 Mach effect
- Case 80 Foreign bodies not visible on radiographs
- Case 81 Accessory ossicles
- Case 82 Fat pad interpretation
- Case 83 Posterior shoulder dislocation
- Case 84 Easily missed fractures in thoracic trauma
- Case 85 Sesamoids and bipartite patella
- Case 86 Subtle knee fractures
- Case 87 Lateral condylar notch sign
- Case 88 Easily missed fractures of the foot and ankle
- Section 8 Pediatrics
- Index
- References
Summary
Imaging description
A radiograph obtained for acute trauma or musculoskeletal extremity pain reveals an extraosseous structure. Close inspection reveals that the bone is round and well corticated on all sides, as opposed to the appearance expected for an acutely avulsed fragment of bone. Perhaps correlation with physical exam reveals no focal tenderness at the site of the accessory ossicle, effectively excluding acute fracture. Alternatively, if the physical exam is unreliable or if clinical suspicion persists, a CT might show the complete cortication and lack of osseous donor site. An MRI may be obtained if there is concern that the accessory ossicle is itself the source of ongoing subacute or chronic pain, in which case bone marrow edema would be revealed on both sides of the synchrondrosis between the accessory ossicle and parent bone.
Importance
The number of described accessory ossicles is very large. Their clinical significance lies in the fact that they can simulate acute avulsions radiographically and they can be symptomatic themselves.
- Type
- Chapter
- Information
- Pearls and Pitfalls in Emergency RadiologyVariants and Other Difficult Diagnoses, pp. 274 - 284Publisher: Cambridge University PressPrint publication year: 2013