LUMBAR LINES OF MENSURATION

ANGLE OF CURVATURE

FERGUSON’S LINE (GRAVITATIONAL LINE FROM

FERGUSON’S SACRAL BASE LINE

GEORGE’S LINE

MCNABE’S LINE

LUMBOSACRAL DISC ANGLE

ULLMAN’S LINE

GRADES OF SPONDYLOLISTHESIS

FILM: Lateral lumbar

NAME: ANGLE OF CURVATURE

PROCEDURE: Draw a line along the top of the body of L1.

Draw a line along the bottom of the body of L5.

Bisect these lines at 90 degrees and extend the bisecting lines until they intersect.

Measure the acute angle formed by the intersection.

NORMAL: 35-40 degrees

SIGNIFICANCE: Above 45 degrees = Hyperlordosis

Below 35 degrees = Hypolordosis

FILM: Lateral lumbar

NAME: FERGUSON’S LINE (GRAVITATIONAL LINE FROM L3)

PROCEDURE: Draw a line from the center of the body of L3 at 90 degrees tot he bottom of the film.

NORMAL: The line should cross the anterior quarter of the sacral base.

SIGNIFICANCE: Line falling anterior to the sacrum = Hypolordosis

Line falling posterior to normal position = Hyperlordosis

FILM: Lateral lumbar

NAME: FERGUSON’S SACRAL BASE ANGLE

PROCEDURE: Draw a true horizontal line from the edge of the film.

Draw a line along the sacral base intersecting the horizontal line.

Measure the acute angle formed by the intersection.

NORMAL: 35-45 degrees

SIGNIFICANCE: Above 45 degrees = Hyperlordosis

Below 35 degrees = Hypolordosis

FILM: Lateral lumbar

NAME: GEORGE’S LINE

PROCEDURE: As with George’s line in the cervical spine.

NORMAL: As with George’s line in the cervical spine.

SIGNIFICANCE: As with George’s line in the cervical spine.

FILM: Lateral lumbar

NAME: MCNABE’S LINE

PROCEDURE: Draw lines along the inferior margins of L1-L4 and extend them past the facets of the vertebra below.

NORMAL: The line should pass superior to the superior facet of the vertebra below.

SIGNIFICANCE: If the top of the facet is above the line, it indicates facetal syndrome.

(AKA facetal imbrication, telescoping facets)

FILM: Lateral lumbar

NAME: LUMBOSACRAL DISC ANGLE

PROCEDURE: Draw a line along sacral base.

Draw a line along the bottom of the body of L5.

Extend both lines until they intersect.

NORMAL: The lines should cross posterior to the IVF. The angle between these lines should be 15-20 degrees.

SIGNIFICANCE: If the line cross in the IVF it indicates telescoping or imbrication of the posterior articular processes. (AKA lumbo-sacral facet syndrome)

FILM: Lateral lumbar

NAME: ULLMAN’S LINE

PROCEDURE: Draw a line at 90 degree to the sacral base line at the anterior margin of the sacral base.

NORMAL: The line should pass anterior to the body of L5.

SIGNIFICANCE: If the line crosses the body of L5, it indicates spondylolisthesis.

FILM: Lateral lumbar spot

NAME: GRADES OF SPONDYLOLISTHESIS

PROCEDURE: Determine which quarter of the sacral base the posterior margin of the body of L5 is superior to.

NORMAL: N/A

SIGNIFICANCE: Posterior L5 body over posterior quarter of sacral base = GRADE 1

Posterior L5 body over third quarter of sacral base = GRADE 2

Posterior L5 body over second quarter of sacral base = GRADE 3

Posterior L5 body over anterior quarter of sacral base = GRADE 4