title: The rib head as a landmark in the anterolateral approach to the thoracic spine: a computed tomography-based morphometric study.
abstract: OBJECTIVE
  The rib head is an important landmark in the anterolateral approach to the thoracic spine. Resection of the rib head is typically the first step in gaining access to the underlying pedicle and ultimately the spinal canal. The goal of this work is to quantify the relationship of the rib head to the spinal canal and adjacent aorta at each thoracic level using CT-based morphometric measurements.
  
  
  METHODS
  One hundred thoracic spine CT scans (obtained in 50 male and 50 female subjects) were evaluated in this study. The width and depth of each vertebra body were measured from T-1 to T-12. In addition, the distance of each rib head to the spinal canal was determined by drawing a line connecting the rib heads bilaterally and measuring the distance to this line from the most ventral aspect of the spinal canal. Finally, the distance of the left rib head to the thoracic aorta was measured at each thoracic level below the aortic arch.
  
  
  RESULTS
  The vertebral body depth progressively increased in a rostral to caudal direction. The vertebral body width was at its minimum at T-4 and progressively increased to T-12. The rib head extended beyond the spinal canal maximally at T-1. This distance incrementally decreased toward the caudal levels, with the tip of the rib head lying approximately even with the ventral canal at T-11 and T-12. The distance between the aorta and the left rib head increased in a rostral to caudal direction as well.
  
  
  CONCLUSIONS
  The rib head is an important landmark in the anterolateral approach to the thoracic spine. At more cephalad levels, a larger portion of rib head requires resection to gain access to the spinal canal. At more caudad levels, there is a safer working distance between the rib head and aorta.
authors: Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors: Kyriakos
authors: K
authors: Papadimitriou
authors: Anubhav G
authors: AG
authors: Amin
authors: Ryan M
authors: RM
authors: Kretzer
authors: Christopher
authors: C
authors: Chaput
authors: P Justin
authors: PJ
authors: Tortolani
authors: Jean-Paul
authors: JP
authors: Wolinsky
authors: Ziya L
authors: ZL
authors: Gokaslan
authors: Ali A
authors: AA
authors: Baaj
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012272:Ribs / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D013115:Spinal Canal / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D013904:Thoracic Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D055815:Young Adult