MODULE 1

Lumbar Spine

• History, persistent history, PM history, family history • Chief Complaint – O, P, P, Q, R, S, T• Physical examination – orthopedic, neurological• Differential diagnosis• Tests to limit differential diagnosis

INTRODUCTION

When to x-ray

• Risks versus benefits ratio• Cost versus benefit ratio• When differential diagnosis includes something to: rule in, rule out or monitor a known condition by x-ray

Who gets x-ray

Shoot Series

ABC’S

• Technical evaluation• Search pattern

Normal Anatomy

Mensuration

• Lumbar spine• Disc height• Hurxthal - measures mid point

of each endplate easy can’t account for

extension or flexionmalposition

distance

Farfan

Anterior height ratio (AHR) = Anterior height Diameter

Posterior height ratio (PHR) = Posterior height Diameter

DH = AHR PHR

More complex posterior anterior Research use height D height

Both Measurements

• Great variation exists• Rotation >40o or lateral flexion >20o

leads to unreliable results

Decrease disc height causes

• Degeneration • Surgery (i.e. discectomy)• Chemonucleolysis• Infection• Congenital hypoplasia

Poor correlation between loss of disc height and pain.

IVD Angles• Lines tangential to the endplates extend until intersection• Measuring angle• Little predictability• Alterations may occur Antalgia Muscle imbalance Poor posture Early DJD Facet syndrome may increase angle Disc herniation may decrease angle

Lumbar Lordosis

• Top of L1 and S1 used or bottom of L5• Draw perpendicular to tangential lines• Measure angle of intersection• Great variety• 50o-60o average

Lumbosacral lordosis angle and sacral inclination not useful.

Lumbosacral Angle(Sacral base angle, Ferguson’s angle)

• Tangential sacral base• Horizontal line• Measure angle of intersection• 41o +/- 7o

It has been suggested that increased angle leads to increased shearing and compressive forces at the facets

No increase in anterolisthesis noted

Static Vertebral Malpositions

• Flexion• Extension• Lateral flexion• Rotation• Anterolisthesis• Retrolisthesis• Laterolisthesis

Lumbar Gravity Line (Ferguson’s, weight bearing, Ferguson’s gravity)

• Center of L3• Plumb line• Should intersect anterior sacral margin +/- 10mm

McNab’s Line

• High number’s of asymptomatic patients make this line’s usefulness doubtful•Was originally used on recumbent films weight bearing may alter utility

Hadley’s Curve

• AP and obliques views used• Interuption of the line may indicate: Rostral/caudal migration Extension malposition Rotational malposition

VanAkkerveeken and flexion and extension have been largely replaced by the more sensitive comp/distraction study.

Lateral Bending Study

• May suggest ligament laxity and/or muscle spasm• Poor correlation between this and clinical picture

Meyerding

• Replaced by the more useful percentage method

• Anteriority sacral base length = % of antero

Ullmann’s Line

• Tangential to sacral base• Perpendicular to and coincide with anterior sacral prominence

• L5 should be at or posterior to line, if anterior, it represents anterolisthesis

Note: decreased lordosis may produce false positive

Interpediculate Distribution and Eisenstein’s and canal body ratio (unreliable) measure for central canal stenosis

Small numbers are suggestive only CT, MR for definitive diagnosis