ACL Imaging Syllabus
2014-02-26
: Pdf Acl Imaging Syllabus ACL_Imaging_Syllabus 2 2014 pdf
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2/25/2014 VuMedi Webinar February 26, 2014 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 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 Anatomy is the Basis of Orthopaedic Surgery “Whenever you are having anatomy sessions, pay particular attention, because orthopaedics is all anatomy, plus a little bit of common sense.” J. Hughston Fracture Fixation 1 2/25/2014 Anatomy of the ACL microscopic view AM AM AM PL PL LFC LFCPL PL PL AM AM Fetus Human Arthroscopic Double-Bundle Anatomy of the ACL Oblique sagittal view Obliquecoronal coronalview view Oblique AM PL PL AM Special Planes – Native ACL Casagranda, Towers, Fu, et al, Am J Roent 2009 Tibial Insertion Site Anatomy PL AM Native tibial insertion sites 3D-CT Reconstruction Forsythe B, Kopf S, Fu, et al. JBJS 2010 2 2/25/2014 Femoral Insertion Site Anatomy AM PL 90° Native femoral insertion sites 3D-CT Reconstruction Forsythe B, Kopf S, Fu, et al. JBJS 2010 Anatomy Never Changes Lucy (3.2 Million years old) Modern Human Lucy (3.2 Million years old) Anatomical Variation <14 SB 14-18 SB or DB >18 DB Accountable for 100% of the Patient Kopf, Fu et al. AJSM, 2011 3 2/25/2014 Insertion Site Variation 13 mm 24 mm 16 mm 20 mm Kopf, Fu et al. AJSM, 2011 Inclination Angle Variation 43° 55° Low High Illingworth, Fu et al. AJSM, 2011 Notch Size Variation 16 mm 24 mm 22 mm 10 mm 20 mm 11 mm 14 mm 22 mm 4 2/25/2014 Animal Kingdom Lion Tiger Bear Lemur Gorilla Kangaroo Collaboration with Pittsburgh Zoo, Carnegie Natural History Museum and Dr. Willem van der Merwe The ACL Underlies the Bony Morphology of the Knee AM PL The AM and PL Bundle Work Synergistically Golano, Fu et al Chhabra and Fu, 2006 Does the ACL Degenerate with Age? 5 2/25/2014 Age-Related Degeneration of the ACL microscopic view AM PL Fetus 30 years old 60 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 AM PL PL AM 6 2/25/2014 Anatomic Single-Bundle MRI Tunnel Placement 3D-CT 68% 63% Anatomic Double-Bundle Quadriceps Tendon Autograft Tunnel Placement MRI 3D-CT 63% AM PL AM 55% PL 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 7 2/25/2014 2013 Hughston Award 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 Level I 85% follow-up at 3-5 years Anatomic DB > Anatomic SB > Conventional SB Individualized Anterior Cruciate Ligament Surgery: A Prospective Study Comparing Anatomic Single- and DoubleBundle 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 Vertical Graft Native Anatomical Graft Higher Re-rupture? Yagi, Fu, Woo et al AJSM 1997 Araujo, Fu, et al, AAOS and ISAKOS 2013 8 2/25/2014 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 Time zero 3 months Healing? 6 months 1 year 9 2/25/2014 See the Big Picture! Anatomy Biology Biomechanics Kinematics Proprioception Rehabilitation Thank You! University of Pittsburgh Cathedral of Learning 10 2/24/2014 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 1 2/24/2014 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 2 2/24/2014 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 3 2/24/2014 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 4 2/24/2014 Resident’s Ridge/ACL Ridge 5 2/24/2014 6 2/24/2014 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 7 2/24/2014 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 8 2/24/2014 Superior Medial Portal The posterior wall of the tibial tunnel should abut the base of the tibial spine and should not enter it 9 2/24/2014 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 10 2/24/2014 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 11 2/24/2014 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 12 2/24/2014 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 13 2/24/2014 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 14 2/24/2014 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 15 2/24/2014 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 16 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 Don Joy Stryker • Research Support 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 • SB = DB 52DB vs 60 SB Song AJSM 2013 Pittsburgh South Korea Anatomic Femoral Tunnel Biomechanics of Anatomic SB vs DB – Ho, Arthroscopy ‘09 PL SB AM Anterior Translation 12 mm 8 mm 4 mm NL cut SB 30° DB NL cut SB 60° DB SB Centered (Anatomic) in ACL Footprint = DB NO YES • Transtibial ACL Increased Translation • • Anatomic ACL Normal Translation 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 Bone plug rotated ACL Footprint Transtibial Drilling Vertical Graft Trying to Find an Anatomic ACL View of the Notch Varies • • • • 55° Best view at 55° Changes with flexion Posterior “closes” with flexion Portal changes perspective 90° 110° 125° Problem with Clock Face Too much variability IKDC Pittsburgh Duke • Knee flexion ? • Horizontal axis ? • Perspective ? Heming AJSM 2007 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: • Depth: 8.5 mm 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 TT AM Flexible Arthroscopy ‘12 42mm 32 mm AM Rigid 54mm Tunnel low at 90° = Tunnel posterior at 20° V extended 90° 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
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