ACL Imaging Syllabus

: Pdf Acl Imaging Syllabus ACL_Imaging_Syllabus 2 2014 pdf

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1

Anatomy of the ACL

Dr. Freddie H. Fu

Distinguished Service Professor

David Silver Professor and Chairman

Department of Orthopaedic Surgery

University of Pittsburgh

Head Team Physician

University of Pittsburgh Athletic Department

VuMedi Webinar

February 26, 2014

Disclosures

Freddie H. Fu, MD, DSc (Hon), DPs (Hon)

None

University of Pittsburgh Department of

Orthopaedic Surgery

Royalties and Stock Options: None

Consulting Income: None

Research and Educational Support: Smith & Nephew

Other Support: Department of Orthopaedic Surgery of the University of Pittsburgh

receives funding from Arthrocare, Synthes, Stryker, Johnson & Johnson,

DePuy, DonJoy, Breg, Omeros, Biomet, Mitek

“Whenever you are having anatomy

sessions, pay particular attention,

because orthopaedics is all anatomy,

plus a little bit of common sense.”

Anatomy is the Basis of

Orthopaedic Surgery

J. Hughston

Fracture Fixation

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Anatomy of the ACL

Fetus

AM PL

microscopic

view

AM PL

AM PL

LFC

AM PL

LFC

AM

PL

Human Arthroscopic

AM

PL

Casagranda, Towers, Fu, et al, Am J Roent 2009

Special Planes – Native ACL

Oblique sagittal view

Double-Bundle Anatomy of the ACL

Oblique coronal view

AM

Oblique coronal view

PL

PL

AM

Tibial Insertion Site Anatomy

Native tibial insertion sites 3D-CT Reconstruction

Forsythe B, Kopf S, Fu, et al. JBJS 2010

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PL

AM

90°

Femoral Insertion Site Anatomy

Forsythe B, Kopf S, Fu, et al. JBJS 2010

Native femoral insertion sites 3D-CT Reconstruction

Lucy (3.2 Million years old) Modern Human

Lucy (3.2 Million years old)

Anatomy Never Changes

Anatomical Variation

14-18 SB or DB

<14 SB >18 DB

Kopf, Fu et al. AJSM, 2011

Accountable for 100% of the

Patient

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13 mm 24 mm

Insertion Site Variation

Kopf, Fu et al. AJSM, 2011

20 mm

16 mm

Illingworth, Fu et al. AJSM, 2011

Inclination Angle Variation

Low

43°

High

55°

Notch Size Variation

24 mm

16 mm

10 mm

22 mm

14 mm

20 mm

22 mm

11 mm

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Lemur Kangaroo

Bear

Tiger

Gorilla

Animal Kingdom

Collaboration with Pittsburgh Zoo, Carnegie Natural History Museum and Dr. Willem van der Merwe

Lion

The ACL Underlies the Bony

Morphology of the Knee

AM

PL

Chhabra and Fu, 2006 Golano, Fu et al

The AM and PL Bundle Work Synergistically

Does the ACL Degenerate

with Age?

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Age-Related Degeneration of the ACL

Fetus 60 years old

AM PL

microscopic

view

30 years old

Age-Related Degeneration of the ACL

20 years old 40 years old 60 years old 80 years old

Intra-Operative Evaluation of the ACL

Young Patient

PL

AM

AM

PL

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Anatomic Single-Bundle

MRI

Tunnel Placement 3D-CT

68%

63%

Anatomic Double-Bundle

Quadriceps Tendon Autograft

MRI Tunnel Placement 3D-CT

AM

PL

AM

PL

63%

55%

Evidence to Support the Interpretation and Use of the

Anatomic Anterior Cruciate Ligament Reconstruction

Checklist van Eck, Fu et al. JBJS Orthopaedic Forum, 2013

Scoring system for “anatomic” ACL

reconstruction

Can be used to grade ACLR on individual

patients or studies

Validated

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Level I

Prospective randomized Clinical Evaluation of Conventional

Single-Bundle, Anatomic Single-Bundle, and Anatomic

Double-Bundle Anterior Cruciate Ligament Reconstruction

Hussein, Fu et al. AJSM 2012

 85% follow-up at 3-5 years

 Anatomic DB > Anatomic SB > Conventional SB

2013 Hughston Award

Individualized Anterior Cruciate Ligament Surgery: A

Prospective Study Comparing Anatomic Single- and Double-

Bundle Reconstruction. Hussein, Fu et al. AJSM 2012

Level II

Individualized surgery

< 16 mm = SB

≥ 16 mm = DB

 No clinical differences

In Situ Force Higher in

Anatomic Graft

Araujo, Fu, et al, AAOS and ISAKOS 2013

Anatomical Graft Vertical Graft Native

Higher Re-rupture?

Yagi, Fu, Woo et al AJSM 1997

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Transtibial ACL Femoral Tunnel Preparation

Increases Odds of Repeat Ipsilateral Knee Surgery

Duffee, MOON Group, Kaeding et al JBJS 2013

Repeat Ipsilateral Knee Surgery

2.5x higher with TT drilling than

AM drilling

Anatomic ACL Reconstruction

Rehabilitation Should Be

Modified Accordingly

Return to Sports

Functional Testing Healing?

3 months

6 months

Time zero

1 year

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See the Big Picture!

Anatomy Biology

Proprioception Rehabilitation

Biomechanics Kinematics

Thank You!

University of Pittsburgh

Cathedral of Learning

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This speaker receives

royalties from

Smith and Nephew

Medial Portal

For

ACL Reconstruction

William G. Clancy, Jr., MD, PhD (Hon)

Medial Portal

Very

distinct advantages

over a

lateral portal

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Medial Portal

Why?

Medial Portal

1. More obliquity of the approach angle to

the LFC

2. Less flexion needed

3. Better visualization of the Bifuricate

Ridge and posterior edge of the LFC

4. Seldom need to perform a notchplasty

5. More accurate tibial tunnel

Medial Portal

To achieve these benefits

need to create

a superior medial portal

for

arthroscopic visualization

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Superior Medial Portal

(Portal of Patel)

This Portal is created just below the

confluence of the inferior medial

portion of the patella and the

medial femoral condyle

with the knee flexed to

approximately 60°

The superior medial portal of Patel

The drill guide is placed in a mid medial portal

Medial Portal

Placed vertically or horizontally

halfway between the medial edge

of the patellar tendon and the

anterior edge of the confluence of the

MFC and the medial tibial plateau

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The scope is placed in a high medial portal at the

confluence of the edge of the patella and

Medial Femoral Condyle

The drill guide is placed in a mid medial portal

Superior Medial Portal

Provides the best possible visualization

for drilling of the ACL tunnel

on the femur

and also for drilling the

correct site on the tibia

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Resident’s Ridge/ACL Ridge

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Superior Medial Portal

The distance between the

arthroscope placed through

a lateral or medial portal for

visualizing tibial k-wire placement

is extremely short making it difficult

for accurate k-wire placement

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Superior Medial Portal

Evaluating many x-rays and MRI

on ACL reconstructions,

I find that in greater than 75%

of these the tibial tunnel is

placed too far posterior

Normal ACL Transtibial ACL

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Superior Medial Portal

The posterior wall of the

tibial tunnel should

abut the base of the tibial spine

and should not enter it

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Superior Medial Portal

This portal allows for an

axial or downward view

of the tibial spine and both the

medial and lateral tubercles and

allows for a more correct tibial tunnel

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Medial and Superior Medial Portals

1. Better visualization of the

lateral wall with the bony

landmarks:

Resident Ridge

Bifuricate Ridge

Posterior Edge of the LFC

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Medial and Superior Medial Portals

2. Placing the knee in a figure 4

position produces increased

varus opening of the

intercondylar space so less

flexion is needed for drilling

and visualization

The scope is placed in a high medial portal at the

confluence of the edge of the patella and

Medial Femoral Condyle

The drill guide is placed in a mid medial portal

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Medial and Superior Medial Portals

2a. A medial portal drilling

along with varus allows for a

more oblique drilling angle

Medial and Superior Medial Portals

2b. Combining this portal

placement and varus with a

curved drill guide and a

flexible reamer allows for a

much smaller oval entrance

tunnel

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Medial and Superior Medial Portals

3. A straight reamer especially

if placed through a lateral

portal can create a very large

entrance diameter oval which

can lead to a too anterior graft

fixation site

Medial and Superior Medial Portals

4. Seldom a need for a lateral

notchplasty

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Lateral Wall Notchplasty

If too much bone is

taken away from the LFC

then containment for

side to side sheer is lost

Lateral Wall Notchplasty

Lateral to medial sheer

has been shown to increase poly wear

in total knees and the loss of

containment by a large notchplasty

could lead to increased

cartilage surface wear

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Notchplasty

Too much notchplasty at the

femoral insertional area will

place the graft too lateral

Small Intercondylar Notch

One technique does not fit all!

Even a flexible reamer system in a

narrowed notch or small knee

cannot always achieve

correct tunnel placement.

A rear entry system should be utilized for

correct placement.

University of Wisconsin

Thank You

Can flexible Reamers Improve Access to the

Femoral Insertion Site

ACL Imaging & Reconstruction Webinar

2014

Mark E. Steiner, MD

New England Baptist Hospital

Boston

Disclosures

•Consulting and Royalties Stryker

•Fellowship Support Arthrex

Don Joy

Mitek

Smith & Nephew

Con Med

•Research Support Don Joy

Stryker

Failures of ACL Reconstruction

•“Failure” up to 25%

•Technical error in tunnel Placement - very common

One vs Two Bundle ACL

SB = DB with AM Drilling (not with TT Drilling)

•SB = DB

10% reinjury in both groups

Ahlden AJSM 2013 Sweden

•SB = DB

32 SB (if footprint ≤ 16 mm) vs 69 DB

Hussein AJSM 2012 Pittsburgh

•SB = DB

52DB vs 60 SB

Song AJSM 2013 South Korea

Anatomic Femoral Tunnel

Biomechanics of Anatomic SB vs DB

– Ho, Arthroscopy ‘09

NL NL cut cut SB SB DB DB

30°

60°

Anterior Translation

4 mm

8 mm

12 mm

AM

PL

SB

SB Centered (Anatomic) in ACL Footprint = DB

•

•

•

Transtibial ACL

Increased Translation Anatomic ACL

Normal Translation

NO YES

Anatomic Transtibial Drilling

Tibial or Femoral Tunnels have to be compromised

Drilling under Tibial Plateau Failed Vertical Tunnel

Anatomic Tibial Tunnel Places a Vertical Femoral Tunnel

Does it Matter if the Tibial or Femoral tunnel is Compromised

•Sometimes good results with TT drilling

•Some compromise is probably OK

•Patellar tendon grafts may particularly forgiving

Transtibial Drilling ACL Footprint Vertical Graft

Bone plug rotated

Trying to Find an Anatomic ACL

View of the Notch Varies

90° 110° 125°

•Best view at 55°

•Changes with flexion

•Posterior “closes” with flexion

•Portal changes perspective

55°

Problem with Clock Face

Too much variability

•Knee flexion ?

•Horizontal axis ?

•Perspective ?

Heming AJSM 2007

IKDC Pittsburgh Duke

Finding the ACL Footprint

Intercondylar and bifurcate Ridges

•Can be difficult

•May be unreliable

Measurements to the ACL Center at 90° flexion

•8.5 mm up lateral wall

•1.5 mm deep to a vertical line from low point

Flexible Reamers = Reconstruction in 90° Flexion

90°

125°

AM Aimer at Height of ACL

→ Point just deep to ACL

•Height: 8.5 mm

•Depth: aimer places slight deep to ACL

8.5 mm

Enlarge Pilot Hole with the Awl

Aimer Placed Through AM Portal

Pin Positioned in Starter Hole

Guidepin Placement

•Pin Exits in safe zone on lateral thigh

Advance Flexible Reamer Over Pin

Tunnels ≈ 40 mm Length

•No violation of posterior cortex

•No injury to medial condyle

54mm

42mm

32 mm

TT

AM Rigid

AM Flexible

Arthroscopy ‘12

Tunnel low at 90° = Tunnel posterior at 20°

V

90°

extended

Nitinol Pin Creates a Straight Tunnel

Interference Screw Fixation with Flexible Screwdriver

at 90°

sheath to protect soft tissue grafts

Biomechanics of Aperture vs Suspensory Fixation

•Femoral socket drilled at an acute angle creates an elliptical femoral

tunnel

•May change the mechanics of the graft

Anatomic Nonimpinging Graft

Keep It Anatomic

Old

Thank you