Enostosis Explained

Synonyms:	Bone island
Field:	orthopedic

An enostosis is a small area of compact bone within the cancellous bone.^{[1] [2]} They are commonly seen as an incidental finding on radiographs or CT scans. They are typically very small and do not cause any symptoms.^[3] Their radiodensity is generally similar to cortical bone.^[4] No treatment is necessary. Multiple enostoses are present in osteopoikilosis.^[5]

Spine

Enostosis is usually found in T1 to T7 for the thoracic spine and L2 to L3 in the lumbar spine. It consists of cortical bone merging with medullary bone with irregular margins. The shape of the lesion is round or oval with a thorn-like margin, up to 2 cm in diameter. In both T1 and T2-weighted imaging, it shows low signal intensity. It is usually presented as a single lesion.^[6]

Further reading

• Greenspan. A. Bone island (enostosis): current concept--a review.. Skeletal Radiology. Feb 1995. 24. 2. 111–5. 7747175. 10.1007/bf00198072. 11248413.

Notes and References

1. Book: Ingle. John Ide. Bakland. Leif K.. Endodontics. 2002. PMPH-USA. 9781550091885. 197. 23 November 2017. en.
2. Book: Davies. A. Mark. Sundaram. Murali. James. Steven J.. Imaging of Bone Tumors and Tumor-Like Lesions: Techniques and Applications. 2009. Springer Science & Business Media. 9783540779841. 253. 23 November 2017. en.
3. Book: Mann. Robert W.. Hunt. David R.. PHOTOGRAPHIC REGIONAL ATLAS OF BONE DISEASE: A Guide to Pathologic and Normal Variation in the Human Skeleton (3rd Ed.). 2013. Charles C Thomas Publisher. 9780398088279. 284. 23 November 2017. en.
4. https://books.google.com/books?id=e3F4NaY3fgQC&pg=PA1900 Page 1900
5. Book: Algra. Paul R.. Valk. Jaap. Heimans. Jan J.. Diagnosis and Therapy of Spinal Tumors. 2013. Springer. 9783642602542. 96. 23 November 2017. en.
6. Orguc . Sebnem . Arkun . Remide . 2014-06-04 . Primary Tumors of the Spine . Seminars in Musculoskeletal Radiology . en . 18 . 3 . 280–299 . 10.1055/s-0034-1375570 . 24896744 . 1089-7860. free .