Retrosomatic Cleft: A Radiology Review

Radiology Corner

Retrosomatic Cleft: A Radiology Review

Jacinda D. Woods, DC1

1Radiology Resident, Palmer College of Chiropractic, Davenport, Iowa

Published: December 2017

Journal of the Academy of Chiropractic Orthopedists

December 2017, Volume 14, Issue 4

This is an Open Access article which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The article copyright belongs to the author and the Academy of Chiropractic Orthopedists and is available at: © 2017 Woods and the Academy of Chiropractic Orthopedists.


A 25 year old male presented with right sided low back pain and left hip pain for the past five months. The patient had also reported history of left iliac fracture.

Plain Films

Figure 1: AP Lumbopelvic Figure 2: Lateral Lumbar


The AP and lateral lumbopelvic radiographic examination revealed L5 left pedicle region sclerosis with a suspected right-sided pars defect. A well-corticated osseous irregularity was detected at the lateral aspect of the left ilium in the region of the anterior inferior iliac spine with adjacent small corticated dystrophic calcification. This was most likely due to a prior avulsion fracture of the rectus femoris. Well-corticated ossicle was noted incidentally at the inferior aspect of the L4 spinous. Mild left lumbar lateral curvature was noted with pelvic unleveling, low on the left. There was no evidence of abdominal mass or calcification and the bowel gas distribution is normal.

CT Images

Figure 3: CT Axial slice Figure 4: CT Axial slice

Pars defect (right) Retrosomatic cleft (left)

Figure 5: CT Sagittal slice Figure 6: CT Sagittal slice

Retrosomatic cleft (left) Pars defect (right)

A previous abdominal computed tomography (CT) was located at a local hospital. The examination revealed a right-sided pars defect at L5 with contralateral sclerosis involving the left pedicle region. A linear defect was also observed involving the posterior aspect of the left pedicle (retrosomatic cleft). These findings are consistent with a grade I spondylolisthesis of L5 with right pars and left retrosomatic defects.

Discussion incidentally at the inferior aspect of the L4 spinous.

A retrosomatic cleft is most commonly defined as linear, vertical defects of the vertebral pedicle.1 This can often be confused with traumatic pedicle fractures. A retrosomatic cleft is commonly seen with contralateral spondylolisthesis.2

Other clefts, in addition to retrosomatic cleft, that are associated with the posterior elements of vertebral bodies are retroisthmic cleft, isthmic spondylolisthesis, spondylolysis, and spina bifida. Retroisthmic cleft is a defect that is posterior to the pars interarticularis and is rare. Isthmic spondylolisthesis is a defect at the pars interarticularis with anterior displacement of the vertebral body. If there is no anterior translation of the vertebral body, this is termed a spondylolysis. Both spondylolysis and isthmic spondylolisthesis can be either developmental or acquired in origin.3


  1. MDCT of variations and anomalies of the neural arch and its processes: part 1–pedicles, pars interarticularis, laminae, and spinous process. AJR Am J Roentgenol. 2011 Jul;197(1):W104-13. doi: 10.2214/AJR.10.5803.
  2. M Soleimanpour, M L Gregg and R Paraliticci. Bilateral retrosomatic clefts at multiple lumbar levels. American Journal of Neuroradiology. September 1995, 16 (8) 1616-1617.
  3. Jarrah Ali Al-Tubaikh, Maximiliun F. Reiser. Congenital Diseases and Syndromes An Illustrated Radiological Guide. 2009, 145-146.