spondylolisthesis

Life University Gonstead Study Club

Sacral Misalignments

2Life University Gonstead Study Club

Where Sacrum Subluxates

At one of the sacroiliac articulations

The lumbosacral articulation

Sometimes both areas are involved simultaneously


Direction of Misalignment

Posteriorward is the direction the sacrum slips when it misaligns with an Ilium or the lowest lumbar

Therefore, “posterior sacrum” has no definitive meaning unless we specify which sacral articulation we are dealing with.


Misalignment at the SI Joint, Ilia Versus Sacral Involvement Ilium misalignment involves both ilia simultaneously, and that each

may have a listing equal in degree but opposite in direction

Sacral misalignment involves a condition where the ilia remain relatively intact with respect to each other, but the sacrum rotates posteriorly away from the corresponding ilium on one side. This is principally a unilateral condition


Normal Pelvis

Distance from center of sacrum to its lateral borders found to be equal. a = b

Sacral Tubercles centered

Ilia show no misalignment


Pelvis with Posteriorly Rotated Sacrum

Unequal distance from the center of sacrum to its lateral borders, the posterior side becoming wider. a > b

Sacral tubercles displaced away from the border of the rotated side.

Relatively slight amount of ilium misalignment

Figure shows a P-L


Measurement of Sacral Misalignment at SI Joint

Horizontal Plane Line of Sacrum is drawn from equal points on either side of sacrum, the most reliable being the junction where the superior articular processes join the alae, called sacral grooves

Horizontal Plane Line of Sacrum will normally be parallel with the femur head line


Malformation of Sacrum

If this line is not parallel with the femur head line, then malformation of sacrum is likely.

Other bilateral points, such as the superior and inferior borders of the auricular surfaces and sacral foramina may be used to confirm

Bilateral structures would normally be parallel to the horizontal plane line if sacral symmetry exists


Posterior and Inferior Sacrum

Inferior tipping considered only after malformation has been ruled out

Inferior tipping only occurs on the side of posterior rotation


Four Potential Sacral Misalignments Involving the SI Joint

P-R (Posterior Sacrum on the Right)

P-L (Posterior Sacrum on the Left)

PI-R (Posterior & Inferior Sacrum on the Right)

PI-L (Posterior & Inferior Sacrum on the Left)


Measurement of Sacral Misalignment at SI Joint


When a Posterior Rotated Sacrum Should be Considered Any sum over 7mm should be

considered significant A difference from 4-6mm with no

misalignment factors in the ilia, the sacrum may still be considered posteriorly rotated

The bodies of the vertebrae above, including axis, must be rotated to the side of posterior sacrum

No scoliosis involved


Measuring For Sacral Inferiority

Remember to rule out apparent inferiority

Roll the parallel superior from the FHL. With the leading edge on the higher dot draw a one-inch line above the lower dot

Make sure the lower side of sacrum coincides with the side of posterior rotation


Rules For Correction

Sometimes there will be no misalignment factors in the ilia at all, in this case sacral posteriority is corrected This will establish a proper relationship at the SI joint

In most cases, some amount of ilium misaignment also exists A proper relationship must be re-established between the posteriorly

rotated sacrum and the involved ilia For example: because a PIEx, PI, or Ex ilium is predominately a

posteriorward misalignment, adjusting the sacrum forward could increase the degree of ilium posteriority


Which to Adjust?

Adjusting Sacrum to Ilium If the ilium listing is AS, In, or ASIn If the ilium listing is ASEx, with the AS predominating If the ilium listing is PIIn, with the In predominating

Adjusting Ilium to Sacrum If the ilium listing is PI, Ex, or PIEx If the ilium listing is PIIn, with the PI predominating If the ilium listing is ASEx, with the Ex predominating


Sacral Misalignment at the Lumbosacral Articulation

Deviation of the normal arcuate line formed by the posterior margins of the lowest lumbar vertebra and sacrum The posterior margin of the body of sacrum would rest behind the body

of the lowest lumbar

Involves only the lumbosacral articulation, and is designated a Posterior Sacral Base

May result from severe trauma to the pelvis, usually from a hard fall on the buttocks Particularly susceptible to a base posterior is the preadolescent whose

sacral articular processes have not fully ossified


Posterior Sacral Base


Spondylolisthesis

Must distinguish between a posterior sacral base and a spondylolisthesis of lowest lumbar A posterior sacral base involves articular processes that have given way The vertebral arch of the lowest lumbar will still be intact, with the bodies

of the vertebrae above still in line

A spondylolisthesis involves a separation defect in the vertebral arch allowing the body of the lowest lumbar to slip forward The lowest lumbar will usually also go forward of the vertebral body

above


Spondylolisthesis


Base Posterior Versus Spondylolisthesis


Which to Adjust?

Sacrum is adjusted up to the lowest lumbar in either case to re-establish normal alignment

In the case of a spondylolisthesis, adjusting the vertebrae above is never indicated, for the risk of increasing the lumbosacral misalignment is too great


Misalignment of the Coccyx

Coccyx does not subluxate it misaligns

Direction of misalignment is usually straight anterior, but can be accompanied by lateral deviation

Coccygeal listings: Anterior (A) Anterior and Right (A-R) Anterior and Left (A-L)