Citation, DOI & article data
The estimated incidence is at ~0.3 per 1000 live births 2.
Recognized associations are many and include:
- Aicardi syndrome
- cleidocranial dysostosis
- gastroschisis 3
- Gorlin syndrome
- fetal pyelectasis 3
- Jarcho-Levin syndrome
- OEIS complex
- VACTERL association
- mucopolysaccharidosis 9
It falls under the spectrum of segmentation anomalies and can involve one or multiple levels.
A hemivertebra acts as a wedge within the vertebral column, resulting in curvature away from the side on which it is present.
A hemivertebra can be classified according to many types which include:
- fully segmental (free)
- not attached to either vertebra above or below
- most concerning
- semi segmental: half segment is fused with vertebra above or below with no intervening intervertebral disc
- not separated from (i.e. connected to) either level above or below
- causes less of a concern
- joined by pedicles to levels above and below
- causes less of a concern
- dorsal hemivertebra: classically results in kyphosis
- lateral hemivertebra: classically results in scoliosis
- ventral hemivertebra (extremely rare): results in lordosis
A hemivertebra may be seen as an asymmetrical vertebral body on sagittal or coronal scanning, while on axial scanning, a focal defect may be seen on either side of the vertebral column 5.
Plain radiograph / CT
Usually directly outlines the bony anomaly and is often seen as a wedge-shaped vertebral body.
Treatment and prognosis
The prognosis can be variable dependant on the type of segmentation anomaly, from being progressive to a non-progressive deformity. The strongest negative impact is when a hemivertebra occurs at the lumbosacral level 7.
- 1. Varras M. Prenatal Diagnosis of Fetal Hemivertebra at 20 Weeks’ Gestation with Literature Review. IJGM. 2010;3:197. doi:10.2147/ijgm.s11532
- 2. Goldstein I, Makhoul I, Weissman A, Drugan A. Hemivertebra: Prenatal Diagnosis, Incidence and Characteristics. Fetal Diagn Ther. 2005;20(2):121-6. doi:10.1159/000082435
- 3. Weisz B, Achiron R, Schindler A, Eisenberg V, Lipitz S, Zalel Y. Prenatal Sonographic Diagnosis of Hemivertebra. J Ultrasound Med. 2004;23(6):853-7. doi:10.7863/jum.2004.23.6.853
- 4. Chen M, Chan B, Lam T, Shek T, Lee C, Tang M. Sonographic Features of Hemivertebra at 13 weeks' Gestation. J Obstet Gynaecol Res. 2007;33(1):74-7. doi:10.1111/j.1447-0756.2007.00483.x
- 5. Ryu J, Cho J, Choi J. Prenatal Sonographic Diagnosis of Focal Musculoskeletal Anomalies. Korean J Radiol. 2003;4(4):243. doi:10.3348/kjr.2003.4.4.243
- 6. Alexander R. Vaccaro (Editor). Mastercases: Spine Surgery. (2001) ISBN: 0865779244
- 7. Robert F. Heary, Todd J. Albert. Spinal Deformities: The Essentials. (2007) ISBN: 1588903419
- 8. Ronald L. Dewald. Spinal Deformities: A Comprehensive Text. (2003) ISBN: 1588900894
- 9. Lachman R, Burton B, Clarke L et al. Mucopolysaccharidosis IVA (Morquio A Syndrome) and VI (Maroteaux–Lamy Syndrome): Under-Recognized and Challenging to Diagnose. Skeletal Radiol. 2014;43(3):359-69. doi:10.1007/s00256-013-1797-y