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Sports Related Injury Disc Biomechanics and Lesions

Terry R. Yochum DC, DACBR, Fellow, ACCR

Alicia M. Yochum RN, DC, DACBR, RMSK

Metatarsal Stress Fracture

• Repetitive Injury

• Stress response

• X-Ray: Periosteal Reaction

• Callus formation

• Sign of attempt at healing

• MRI: Bone marrow edema

• Present even BEFORE it Fractures

• Location

• 2nd Metatarsal: March fracture

• 3rd

• 5th Near peroneus brevis insertion

Case Courtesy of Jamie Bedle DC, DACBR

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One Month Later

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Fracture line

Reactive sclerosis

FATIGUE FRACTURE

T2

T2

T1

T2

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Athletic Hernia – Sports Pubalgia• Encompasses musculoskeletal

processes occurring around the pubic symphysis • Rectus abdominis Lat>Med

• Adductor muscles (MC Longus)

• Osteitis Pubis

• Occurs with twisting or sudden changes in motion

• Repetitive unbalanced contraction

• S/S: acute or insidious inguinial/groin pain that may radiate to the adductors or perineum, point tenderness

• TX: conservative vs surgery

Adductor tear Pubis Edema

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• CAM- Bump

• Pincer – Over coverage • Center Edge Angle: >40

Degrees

• Mixed

• Anterior pain on full flexion and internal rotation

Hip Impingement and Labral Tearing

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Labral Tear

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Acetabulum

Femoral Head

Labrum

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Ligament Injury • Grade 1: Minor Sprain

• Fluid within the ligament without visualized disrupted fibers

• Grade 2: Severe Sprain/Partial tear• Discontinuous fibers

• Grade 3: Complete tear

• Signs of Injury • Non visualization of the ligament

• Fluid in the region of the ligament

• Displacement of the normal ligament fibers

• Bone marrow edema

Unhappy TriadO’Donoguhe

• ACL tear

• MCL tear

• Meniscal Tear • Historically been taught as medial • Recent literature argues for lateral

meniscal tear with acute injury

• Occurs with valgus load- Pivot Shift

• Common in football and skiing

• Pentad • Medial Patellofemoral ligament • Lateral meniscal Injury

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Cruciate LigamentsAnterior Cruciate Ligament

• Origin: Lateral femoral condyle (medial)

• Insertion: Medial tibial eminence (anterior)

• Function: Resists anterior translation of tibia

• Synovial membrane envelope

• 2 Bundles • Anteriomedial: Smaller-Tight in flexion • Posteriolateral: Larger- Tight in

extension

Normal ACL

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Lateral Medial

ACL

PCL

ACL tear: Pivot Shift- Kissing Contusions • Look for bone

marrow edema to suggest injury

• Lateral Femoral condyle

• Posterior lateral tibial plateau

http://www.radiologyassistant.nl/en/p42764e8fe927e/knee-non-meniscal-pathology.html http://pubs.rsna.org/doi/full/10.1148/radiographics.20.suppl_1.g00oc19s135

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Deep Sulcus Sign – 1.5 mm

Check ALL Planes!

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Collateral Ligaments

•Medial Collateral Ligament• Origin: Superiomedial aspect of the

medial femoral condyle • Insertion: Medial tibial condyle 2-5cm

distal to the tibial plateau • Has several layers, the innermost of

which is attached to the medial meniscus

• Function: Resists valgus angulation of Knee

Medial Collateral Ligament

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Achilles Tendinosis

• Thickened tendon

• Fluid within the fibers

• May have some partial thickness tearing

Achilles Tendinopathy-Ultrasound

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Achilles Tendon Near Rupture

• Fluid is black on Ultrasound

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Ligament Injury • Grade 1: Minor Sprain

• Fluid within the ligament without visualized disrupted fibers

• Grade 2: Severe Sprain/Partial tear• Discontinuous fibers

• Grade 3: Complete tear

• Signs of Injury • Non visualization of the ligament

• Fluid in the region of the ligament

• Displacement of the normal ligament fibers

• Bone marrow edema

Plantar Fascia (Aponeurosis) • Thin Ligament directly beneath the skin

• Absorbs the shock placed on the foot when walking

• Divides into 5 sections extending to each toe

• Functions to prevent eversion during heel rise

• Arises predominantly from the medial calcaneal tubercle

• Central Band: Implicated in plantar fasciitis

• Medial Band: Very thin

• Lateral Band: Attaches to the base of the 5th

metatarsal - Absent in 12% of the population

The Pathomechanics of Plantar Fasciitis – Sports Medicine

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Calcaneal Enthesopathy

• Remember inflammatory arthritis • Reactive

http://pubs.rsna.org/doi/figure/10.1148/radiol.2482062110#

Advanced Imaging • Computed Tomography

• Best for bony anatomy- fractures

• Magnetic Resonance Imaging • Physiologic imaging- most sensitive • T1: Good at evaluating bony anatomy

• Fat is white

• T2: Good at evaluating fluid/pathology • WATER is white • WWII (Water is white on T2)

• Diagnostic Ultrasound • Good soft tissue resolution and can evaluate blood flow • Allows for movement/orthopedic tests during the exam• Limited at evaluating articular/internal joint structures • Very limited in the spine

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Edema in the Adjacent Soft tissues

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Disc Biomechanics and Lesions

MRI – Pulse Sequences

Sequence Fat Water

T1 High - White Low - Black

T2 Low - Black (Grey) High - White

STIR Very Low - Very Black High - White

WWII = Water is White on T2

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• Disc Pressures • External load- body weight

• Internal load- muscle stabilization

• Seated - Standing - Supine

• Increased pressures at L3/4 and below

• Seated in flexion

• Positional Changes

• Flexion

• Extension

Biomechanics of the Disc

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Intradiscal pressure decreases were greatest during flexion and traction

Distraction decreases disc pressures

Disc Degeneration and Biomechanics

• Function of the disc• Compressive

• Tensile and shear

• Nucleus and Annulus

• Loss of disc height = more horizontal orientation

• Decrease proteoglycan content and increased collagen with change to more fibrotic tissue • Water content decreases from ideal level of 70-

80%

• Produces a stiffer nucleus = limits the shock absorption (alerted loading)

• Early- disc may be unstable

3x’s stronger than Horizontal

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Recommendations of the Combined Task Forces: North American Spine Society

American Society of Spine RadiologyAmerican Society of Neuroradiology

Adopted by the ACR and ACCR

Fardon DF and Millette PC. Spine 26:E93-113, 2001

2014 updated from 2001Spine Journal

Direction- Posterior

• Central Canal Zone• Right/Left Central

• Subarticular Zone • Lateral Recess

• Foraminal Zone

• Extraforaminal Zone • Far Lateral

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DISC DEGENERATIONCLASSIFICATION

•Bulge

•Herniation• Protrusion• Extrusion

• Migration

• Sequestered

Annular Bulge

• Apparent generalized extension of disc beyond the edges of the apophyses

• Greater than 50% of the circumference of the disc and extends a relatively short distance, usually less than 3 mm

• More or less used only as a descriptive term of morphology

• Annular bulging may be normal in some individuals

• Does not imply any knowledge of etiology,

prognosis, need for treatment or necessarily imply the presence of symptoms

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Disc Bulge

Sagittal Axial

Anterior

Posterior

Disc Bulge

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Bulge

Herniation

• Localized displacement of disc material

• May be a protrusion or extrusion

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Protrusion

• Base of the lesion at the origin is broader than disc material beyond the disc space

• Most commonly seen herniation

• Contained- remains within the PLL/outer annular fibers

• Non-Contained- breaks through the PLL/outer annular fibers

Disc Herniation - Protrusion

Sagittal Axial

Posterior

Anterior

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Protrusion

SUGGESTS NON-CONTAINED

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Protrusion

Protrusion

Case Courtesy of Dr. Charles Portwood ,LCC

Broad Based =>25%

Some call this an asymmetrical bulge

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uwmsk.org

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Extrusion

• Disc material beyond the disc space is broader than the base

• Most are symptomatic• Jenson MC, Brant-Zawadski MN et al. MRI of the lumbar spine

without back pain. N Engl J Med 1994; 331:69

Disc Herniation - Extrusion

Sagittal Axial

Anterior

Posterior

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Case courtesy of mypacs.com

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Radiopaedia.org

MIGRATION

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Case courtesy of mypacs.com

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Protrusion Extrusion

Annular tear/fissures

• Separation between fibers, avulsion from vertebral body insertions, breaks through fibers

• May be classified as:• Circumferential- Concentric

• Radial

• Transverse- Horizontal

Annular fissuring does not imply a traumatic

etiology!!!!

Cramer and Darby “Basic and Clinical Anatomy of the Spine, Spinal Cord and

ANS”

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Annular Fissure

Sagittal Axial

Anterior

Posterior

High Intensity Zones (HIZ’s)

• Area of high signal intensity within the disc on T2-weighted MRI’s

• Reflects annular fissure

• Not to imply knowledge of etiology, concordance with symptoms, or need for treatment

• Has not been related to instability within the spine

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HIZ and Protrusion

Annular Fissure- HIZ’s

• Studies showing a high correlation between HIZ’s and concordant pain with discography

• April, C, Bogduk, N. “High intensity zone”: Br. J Radiol 1992; 65:361

• Shellas, K. et al. “Lumbar disc high intensity zone”. Spine 1995

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High Intensity ZoneReliable Marker of Symptoms Unreliable Marker of Symptoms

Aprill & Bogduk – 1992 Jensen et al – 1994

Schellhas et al – 1996 Ricketson et al – 1996

Saiffudin et al - 1998 Stadnik et al - 1998

Right annular fissure

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Sequestration

• A “free fragment”

• In the category of extrusion

• Extruded disc material that has lost continuity with it’s disc of origin

Disc Herniation - Sequestration

Sagittal Axial

Anterior

Posterior

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Sequestered Fragment

• Often hard to tell if its connected

• Radiologist may “hedge”

• Always clinically correlate

• NOT a “surgical back” as previously thought

• Fragment may phagocytize and disappear

Sequestration

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L5/S1 Disc-S1 Root

Move Lateral- L5 Root

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Review

http://spinwarp.ucsd.edu/neuroweb/Text/sp-700.ht

Contrast: Gadolinium (Gd-DTPA)• When to use it

• Intravenous• Spine: disc herniation vs. scar

• Mass: cyst vs. solid

• Mass: tumor vs. necrosis

• Infection: abscess vs. phlegmon

Musculoskeletal MRI, Kaplan, Helms, et al.

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Central Canal Stenosis • Disc Lesion

• Facet degeneration

• Synovial Cyst

• Ligamentum flavum hypertrophy >4mm

• Lack of epidural/perinural fat

• Absent fluid around nerves

Grading:

• Mild: <1/3

• Moderate: 1/3-2/3

• Severe: >2/3

Disc

Facet

Lig Flavum

Facet

1. T1- Low T2 High• Essentially bone marrow edema

• Can be painful

• Microinstabilty

2. T1- High T2 High• Marrow Conversion: fatty replacement

3. T1- Low T2 Low• Sclerotic bone

1 2 3http://www.ajnr.org/content/29/5/838.full

Prevalence between 19-59%

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MODIC TYPE 1

www.rachis-toulouse.com

MODIC TYPE 2

T1 T2http://www.ajnr.org/content/29/5/838/F2.expansion.html

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MODIC TYPE 3

T1 T2

Rotator Cuff Tears

• Most common cause of shoulder pain and dysfunction in adults

• Critical zone = 1 cm medial to insertion

• Most commonly related to degeneration

• Commonly from overuse

• 50% of patients >66 who present with painful tear will have an asymptomatic one on the other side

• Fluid Filling the defect = most DIRECT sign of a tear

• Fluid may sit on both sides of the rotator cuff

• Tendon retraction (Full thickness)

• Muscular atrophy – Fatty Muscle (Chronic)

• Accuracy of MRI and US for full thickness is >90%

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Plain Film

• Flattening or degenerative cystic changes at the Greater Tuberosity

• Inferior osteophytosis-clavicle

• Superior Migration <6mm

Supraspinatus TEAR with TENDON Retraction

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Normal sagittal for comparison Note fatty atrophy of Supraspinatus muscle

Clues in the fluid…

Subdeltoid Bursa Subscapular Recesses- NORMAL

Subcoracoid Bursa

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Arthrogram Non Arthrogram

Ultrasound- Supraspinatus Tendon (SST)

GT

GT

SST

SST

GT

Deltoid

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Transverse View- Cuff

SST- Supraspinatus

IST- Infraspinatus

SubS- Subscapularis

Sagittal T2

SST

ANT POST

IST

Tmin- Teres Minor

BT- Biceps Tendon

Partial Thickness Tear

• Twice as common as Full Thickness

1. Articular Sided – Most common

1. Rim Rent Tear

2. PASTA- partial articular sided SST avulsion

2. Bursal Sided

3. Intrasubstance

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• 2 year arthrographic follow up on partial thickness tears (40)• 80% progressed to full

thickness

• 10% decreased in size

• 10% disappeared

One year follow up shows full thickness tear

Intrasubstance

Articular sided

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FLUID?

Bursal Sided Partial Thickness Tear

Coronal Fat Suppressed T2 Sagittal T2 Radsource.us

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Tendinosis

• Thick

• Grey • NO focal fluid

• T2

SST

GT

Subdeltoid Bursa

T1

T2