Objective Measurement for Objective Measurement for Lumbar Spinal AngelsLumbar Spinal Angels

Submitted ToSubmitted To

Prof. Dr. Maher El-keblawyProf. Dr. Maher El-keblawyProfessor of Basic Science DepartmentProfessor of Basic Science Department

Faculty of Physical TherapyFaculty of Physical TherapyCairo UniversityCairo University

The specific parts that make up the The specific parts that make up the spinespine

11 . .Vertebrae (Vertebrae (five vertebral bodies)five vertebral bodies)..

22 . .Intervertebral DiscIntervertebral Disc..

33 . .Facet JointFacet Joint..

44 . .Spinal SegmentSpinal Segment..

55 . .Paraspinal MusclesParaspinal Muscles..

Motion in the lower backMotion in the lower back

Fifty percent of flexion (bending forward) Fifty percent of flexion (bending forward) occurs at the hips and fifty percent occurs occurs at the hips and fifty percent occurs

at the lower spine (lower back). at the lower spine (lower back).

The motion is divided between the five The motion is divided between the five motion segments in the lower back, motion segments in the lower back,

although a disproportionate amount of the although a disproportionate amount of the motion is at L4-L5 (lumbar segment 4 and motion is at L4-L5 (lumbar segment 4 and

5) and L3-L4 (lumbar segment 3 and 4).5) and L3-L4 (lumbar segment 3 and 4).

Spinal anglesSpinal angles

The proper assessment of the The proper assessment of the sagittal plane in normal or sagittal plane in normal or

deformed spines remains a topic of deformed spines remains a topic of discussion at most spine meetings discussion at most spine meetings

today.today.

Normal sagittal balanceNormal sagittal balanceSagittal balance is the Sagittal balance is the alignment of C7 to the alignment of C7 to the

posterior superior aspect of posterior superior aspect of the sacrum on an upright the sacrum on an upright

radiograph.radiograph.

The sagittal plumb line, as The sagittal plumb line, as drawn from center of C7, drawn from center of C7,

should be plus or minus 2 should be plus or minus 2 centimeters from the sacral centimeters from the sacral

promontory.promontory.

The impact of pelvic obliquity The impact of pelvic obliquity and lower extremity joint and lower extremity joint

angulation (hip or knee angulation (hip or knee flexion) on this posture are flexion) on this posture are

negated.negated.

Is sagittal balance congruent, Is sagittal balance congruent, compensated or uncompensatedcompensated or uncompensated??

The patient's posture may or may not allow them to achieve balance in the sagittal plane.

The degree to which we assign balance to the sagittal plane is defined by our plumb line and its relationship to an axis of rotation about the hips.

This concept makes assessment of both hip positions on the standing sagittal spine film very

important.

Figure (3): Method of measurement of various parameters of Figure (3): Method of measurement of various parameters of saggittal spinal alignment; a) Angle of thoracic kyphosis, b) saggittal spinal alignment; a) Angle of thoracic kyphosis, b)

angle of lumbar lordosis, c) angle of sacral inclination. angle of lumbar lordosis, c) angle of sacral inclination. (Adapted from Clinic. Rheumtol by Tuzun C 1999)(Adapted from Clinic. Rheumtol by Tuzun C 1999)

Normal sagittal balanceNormal sagittal balance The central nervous system comprises a complex

network of balances that maintain this posture.

Normal sagittal balance = congruent postural alignment of cervical lordosis, thoracic kyphosis and lumbar lordosis

that is proportional and produces a sagittal plumb line passing from the center of C7 through the L5-S1 disc

space or within 2 centimeters of the sacral promontory and through or behind the hip axis.

Overall, there is a positive correlation between thoracic kyphosis and lumbar lordosis.

Compensated (incongruent) Compensated (incongruent) sagittal balancesagittal balance

Our posture changes with age.

We tend to develop more cervical lordosis, thoracic kyphosis and less lumbar lordosis as we

age.

If our spinal components are not capable of acquiring those postures, adaptive changes occur

in the lower extremities.

Compensated (incongruent) Compensated (incongruent) sagittal balancesagittal balance

Compensated (incongruent) sagittal balance = disproportional change in segmental alignment, i.e. cervical, thoracic or lumbar resulting in a shift in the

sagittal plumb line.

The sagittal plumb line remains within the L5-S1 disc space or within 2 centimeters of the sacral promontory by

changes in knee flexion or pelvic angulation (flexion or extension) around the hips in addition to the remaining

flexible spinal segments.

Uncompensated sagittal Uncompensated sagittal balancebalance

Uncompensated sagittal balance = changes in segmental alignment that are not successfully accounted

for by changes in flexible spinal segments, knee flexion and pelvic angulation.

This results in a shift of the sagittal plumb line either anterior or posterior to the L5-S1 disc space and greater

than two centimeters from the sacral promontory.

However, the patient is able to stand up without external support.

Should routine assessment of sagittal Should routine assessment of sagittal balance include the orientation of hips balance include the orientation of hips

and pelvisand pelvis??

While the actual lumbar lordosis is important, pelvic angulation due to hip

flexion or extension can significantly affect each person's spinal posture.

Jackson and Legaye have commented on the effect changes in lumbar lordosis have

on the pelvis, sacrum and hips.

John and Fisher in 1994 concluded that the center of rotation was along an axis through the center of the femoral head. Hip extension, knee

flexion and posterior pelvic angulation are an attempt to return the body's center of gravity to a

more centered location over the hips.

Pelvic morphology can affect posture, so different measurements for pelvic morphology in the sagittal plane have been reported, including the pelvisacral angle, the pelvic incidence angle

and the pelvic lordosis angle.

Lumbosacral angle:Lumbosacral angle:

Accounting for the wedge shape of the L5-S1

intervertebral disc

The angle between intersecting lines drawn

according to the lower endplate of L5 and the

superior endplate of S1.Figure (4): Methods of measuring

the lumbosacral angle (2).

Pelvisacral angle:Pelvisacral angle:

The angle of intersection between the line from a

midpoint between the center of the hip joints to the center

of the superior S1 endplate and a tangent line drawn

along this endplate.

Figure (5):Methods of measuring sacral inclination angle (3).

Sacral Inclination:Sacral Inclination: The angle of intersection

between a line drawn along the back of the S1

vertebra and the horizontal.

Figure (6):Methods of measuring sacral inclination angle (1).

Radiological evaluation of lumbar Radiological evaluation of lumbar intervertebral instabilityintervertebral instability

Functional Radiography can demonstrate intervertebral instability or abnormal motion

between two vertebrae.

Dynamic radiographs obtained in both flexion and extension prove to be a simple

and reliable method to determine motion segment instability and can also indicate the

lesions located in specific areas based on the "dominant lesion".

Figure (7): Plain x-ray radiography for lumbar spine.

Radiological evaluation of lumbar Radiological evaluation of lumbar intervertebral instabilityintervertebral instability

The location of the dominant lesion determines the pattern of instability:

If the dominant lesion is primary anterior restraint failure,

there is posterior horizontal translation in the extension views.

If the dominant lesion is primary posterior restraint failure, there is anterior horizontal displacement in the flexion view

and radiologically detectable abnormal patterns of coupling in the posterior elements.

SummarySummary

Sagittal balance is a combination of opposing curves; cervical lordosis, thoracic kyphosis, lumbar lordosis, sacral inclination, pelvic and hip angulation (flexion or extension).

Sagittal balance has as its primary goal maintaining our center of gravity. Lumbar lordosis has the largest

dampening effect on this balance.

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