MODULE 1 Lumbar Spine
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