Cervical Vertebra
Only the anterior and posterior epiphyses on the body of the element are considered when coding whether the element is fused or un-fused. Loose un-fused anterior or posterior epiphyses unassociated with the rest of the element are coded as being weathered condition and given their appropriate BU. Epiphyses on the spinous and transverse processes are ignored in considering element fusion. When isolated un-fused epiphyses from the spinous or transverse processes are identified, they are coded as “undifferentiated” BU.
For the Fincastle Project, Bone Units 23 (previously undefined in the 1991 edition), and 33-41 were added.
BU 1
SC A
Complete element.
BU 11
SC B
Element complete except for small to moderate amount of crushing on crest of spinous process only.
BU 5
SC C
Element complete except some crushing of one or both transverse processes and, usually, also the spinous process.
BU 30
SC D
Unit is essentially complete, with the exception of missing one posterior articular process. (WU)
BU 13
SC E
Element complete except for complete removal of one or both lateral transverse processes- probably by crushing. Spinous process may also be lightly battered at crest.
BU 16
SC F
Element complete except for moderate to extensive damage to the spinous process and to one or more of the lateral or ventral branches of the transverse process. (DS)
BU 27
SC G
Dorsal anterior 1/3 – ½ of body plus arch and one or both anterior articular processes. Spine is usually removed and posterior articular processes may be removed.
BU 4
SC H
Consists primarily of dorsal 1/3 – 2/3 of vertebral body and vertebral arch. Ventral portion of body removed and transverse processes lightly damaged pr completely removed. Crest of spinous process usually lightly crushed.
BU 10
SC I
Consists of approximately half of arch, with one foramen transversarium and complete or base of spinous process.
BU 26
SC J
Element complete except all or most of spinous process removed.
BU 20
SC K
Complete vertebral body with any two to all four anterior and/or posterior articular processes. Spinous, lateral transverse, and ventral transverse processes all absent. (DS)
BU 28
SC L
Anterior portion of vertebral body. Base of arch and base of spinous process may or may not be present. Lateral and ventral transverse processes usually but not necessarily absent. (KK)
BU 6
SC M
Body of element with one or both transverse processes present. One of either the anterior or posterior articular processes may be present but all of spinous process and most of arch always absent.
BU 17
SC N
Essentially complete vertebrae body with processes either absent or badly damaged. Arch and spinous process absent. (DS)
BU 25
SC O
Vertebra arch with crest of spinous process absent. All to none of shaft of spinous process may be present. Both anterior and posterior articular processes present. One or both foramen transversarium present. Lower 1/2 to 2/3 of body missing. All or base of lateral branches of transverse processes present. All of dorsal branches of transverse processes absent. (TH)
BU 2
SC P
Consists of vertebral arch with body and transverse processes removed. All or part of spinous process absent and one or more of anterior and posterior articular processes removed.
BU 31
SC Q
Essentially ½ of the vertebra. The entire centrum, ½ or less of the neural arch, one foramen transversarium, and the posterior and anterior articular facets of one side are present. The spinous process is damaged or missing, and the ventral and lateral branches of the transverse process may or may not be intact. Similar to BU 22, but with entire centrum. (WU)
BU 22
SC R
Unit consists of the lateral ½ or less of vertebrae body with one foramen transversarium, and ½ or less of arch minus spinous process. The anterior and/or posterior articular surfaces and the lateral and ventral branches of transverse process on one side may be represented. A portion of the centrum may or may not be present. (DS)
BU 24
SC S
Unit consists of ½ of vertebral arch with spinous process totally or largely incomplete; and one partial or complete anterior and posterior articular process. Also, portion of one foramen transversarium and up to 1/3 of adjoining vertebral body may be present. (DS)
BU 14
SC T
Approximately ½ of vertebral arch including all or a portion of one anterior and one posterior articular process. None or spinous process, foramen, transversarium, or centrum represented. (JB)
BU 18
SC U
Fragment consisting of from 0-1/4 of body; all or portion of one lateral transverse process and all or portion of one foramen transversarium. (DS)
BU 3
SC V
Small fragment consisting of either anterior or posterior articular processes. Frequently indicates number of pieces only.
BU 12
SC W
One of lateral branches of transverse processes detached from the element. Frequency indicates number of pieces only.
BU 9
SC X
Approximately 1/3 - 2/3 of body with rest of element absent.
BU 29
SC Y
Arch and posterior articular processes.
BU 8
SC Z
Consists of both anterior articular processes and dorsal anterior 1/3 of body. Remainder of element absent.
BU 32
SC AA
Unit consists of the complete body of the element. Similar to BU 9, but with the inclusion of the entire centrum. (WU)
BU 19
SC BB
Quarter or less of vertebral body identifiable by presence of either anterior or posterior articular surface. Not an unfused epiphysis.
BU 7
SC CC
Small fragment identifiable by presence of a foramen transversarium. Frequency indicates number of pieces not number of elements.
BU 15
SC DD
Unit consists of the complete spinous process detached near the base with none of the arch represented. The immediate crest may be slightly crushed. Similar to BU 21. (JB)
BU 21
SC EE
Distal end of spinous process. Less than ½ of the process is represented. Similar to BU 15. (DS)
BU 23
SC FF
Portion of spinous process. (SB)
BU 33
SC GG
Broken sagitally; missing posterior body. (SB)
BU 34
SC HH
Entire body present. May have small portions of processes attached. (SB)
BU 35
SC II
Anterior 1/3 of the body. Anterior or posterior articular processes may be present. (SB)
BU 36
SC JJ
All or most of spinous process present, top of vertebral arch with one or both articular processes. (SB)
BU 37
SC KK
Similar to BU 29, but contains the anterior articular surfaces as well. (SB)
BU 38
SC LL
Fragment of the ventral portion of the body. (SB)
BU 39
SC MM
Anterior centrum. (SB)
BU 40
SC NN
Posterior centrum. (SB)
BU 41
SC OO
Identified based on shape and curvature. (SB)