The abnormalities documented in the cervical region were 8 hemivertebrae (C5 2x, C6 3x, C7 3x) followed by four dogs with atlanto-axial instability, and one dog with block vertebrae (C2-C3).
There were 33 hemivertebrae (Th5 2x, Th6 4x, Th7 5x, Th8 8x, Th9 4x, Th10 7x, Th11 2x, Th13 1x), 3 dogs with a 14th thoracic vertebrae, 3 dogs with a block vertebrae (Th12-13 1x, Th13-L1 2x), 2 dogs with fused spinous processes (Th8-Th9, Th9-Th10), 1 dog with spina bifida, and 1 dog with only 12 thoracic vertebrae.
These vertebral irregularities were vast and included aberrant ossification centers of the cervicothoracic junction, irregularly ossified vertebrae, significantly widened or reduced interpedicular distances, butterfly vertebrae, hemivertebrae, block vertebrae
, hypoplasia of the anterior vertebral bodies, widened or incompletely fused lumbar posterior arches, and nonossification of lower sacral segments.
Radiography of the cervical spine (Lateral view) showed fusion of 5th and 6th cervical vertebra (Block vertebrae
), elevated right scapula, crowding of ribs with hemi upper dorsal vertebrae.
In 2(%) cases there was a continuous involvement of adjacent vertebrae causing block vertebrae
. There was mild thickening of anterior and posterior longitudinal ligaments in 14 (51.8%) and moderate thickening in 08(29.6%) cases (Fig.1).
An investigation into the validity of cervical spine motion palpation using subjects with congenital block vertebrae
as a 'gold standard' Humphreys BKIM, Delahaye M, Peterson CK BMC Musculoskeletal Disorders 2004, 5:19 (15 June 2004) http://www.biomedcentral.com/content/ pdf/1471-2474-5-19.pdf
The block vertebrae may cause restricted movements, premature degenerative changes and associated neurological deficits.
The block vertebrae were studied and compared with their normal counterparts for analysis of body, lamina, pedicles, costal facets, foramina transversarium (FT), intervertebral foramina (IVF) and vertebral foramen (VF).
Measurements of the block vertebrae were taken with the help of a standard ruler.
RESULTS: Among a total of 2400 vertebrae examined, we identified 6 specimens of block vertebrae belonging to different levels which accounted for a total incidence of 0.25%.
DISCUSSION: Block vertebrae mostly are attributed to developmental defects during differentiation of vertebral column, caused by non-segmentation of the primitive sclerotome.
Case 38 "Block vertebrae
" is presented in a way that reveals poor reasoning.