what does “anatomic” what does “anatomic” really mean ” really...
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Charles H. Brown Charles H. Brown Jr.,MDJr.,MDAbu Dhabi, United Arab Emirates Abu Dhabi, United Arab Emirates
What Does “Anatomic” Really Mean and How Do You Get There?
What Does What Does ““AnatomicAnatomic”” Really Mean Really Mean and How Do You Get There?and How Do You Get There?
Royalties: Royalties: EndoButtonEndoButton CL, Smith and Nephew, CL, Smith and Nephew, Royalties: GTS Screws, Smith and NephewRoyalties: GTS Screws, Smith and NephewRoyalties: Royalties: AcufexAcufex Anatomic Director Program, Anatomic Director Program, Smith and Nephew, Smith and Nephew, Product Development, Research & Educational Product Development, Research & Educational Consultant: Smith and NephewConsultant: Smith and Nephew
I, Charles H Brown Jr.,MD
have relevant financial relationships to be discussed, directly or indirectly, referred to or illustrated with or without recognition within the presentation as follows:
Not all ACL Reconstructions are Anatomic!Not all ACL Reconstructions are Anatomic!Not all ACL Reconstructions are Anatomic!
19951995–– 2005: 42005: 4--strand hamstring tendon graftsstrand hamstring tendon graftsSurgical technique: Surgical technique: TranstibialTranstibial
Femoral Tunnel AngleFemoral Tunnel Angle
Graft Inclination AngleGraft Inclination Angle
Anatomic SB ACL ReconstructionAnatomic SB ACL ReconstructionAnatomic SB ACL Reconstruction
2006: 5 and 62006: 5 and 6--strand hamstring tendon graftsstrand hamstring tendon graftsSurgical technique: Medial portal techniqueSurgical technique: Medial portal technique
Femoral Tunnel AngleFemoral Tunnel Angle
Graft Inclination AngleGraft Inclination Angle
Over the last decade, the concept of Over the last decade, the concept of ACL reconstruction has evolved from ACL reconstruction has evolved from ““isometricisometric””
nonnon--anatomic anatomic
reconstructions positioned to avoid roof reconstructions positioned to avoid roof impingement towards impingement towards ““anatomicanatomic””
reconstructions which attempt to reconstructions which attempt to restore the native anatomy of the ACL.restore the native anatomy of the ACL.
Concept of ACL ReconstructionConcept of ACL ReconstructionConcept of ACL Reconstruction
Concept of SB ACL ReconstructionConcept of SB ACL ReconstructionConcept of SB ACL Reconstruction
High AMHigh AM
PLPL
CenterCenter
CenterCenter
Definition of “Anatomic” ACL ReconstructionDefinition of Definition of ““AnatomicAnatomic”” ACL ReconstructionACL Reconstruction
“Anatomic”
ACL reconstruction is defined as the functional restoration of the ACL to its native dimensions, collagen orientation, and insertion sites.
““AnatomicAnatomic””
ACL reconstruction ACL reconstruction is defined as the functional is defined as the functional restoration of the ACL to its restoration of the ACL to its native dimensions, collagen native dimensions, collagen orientation, and insertion sites.orientation, and insertion sites.
Anatomic SingleAnatomic Single--
and Doubleand Double--Bundle Bundle Anterior Anterior CruciateCruciate
Ligament Flowchart Ligament Flowchart
van Eck, van Eck, LesniakLesniak, Schreiber, Fu , Schreiber, Fu Arthroscopy, 2010Arthroscopy, 2010
““AnatomicAnatomic””
SB ACL reconstruction refers to a SB ACL reconstruction refers to a SB reconstruction in which the femoral and SB reconstruction in which the femoral and tibialtibial
bone tunnels are placed at the center of bone tunnels are placed at the center of
the native femoral and the native femoral and tibialtibial
attachment sitesattachment sites
What Does “Anatomic” Really Mean?What Does What Does ““AnatomicAnatomic”” Really Mean?Really Mean?
Principles of Anatomic ACL ReconstructionPrinciples of Anatomic ACL ReconstructionPrinciples of Anatomic ACL Reconstruction
••
Restore the size, position and orientation of Restore the size, position and orientation of the native ACL attachment sites the native ACL attachment sites
••
Restore the 2 functional bundles of the ACLRestore the 2 functional bundles of the ACL
••
Restore the native tensioning pattern of each Restore the native tensioning pattern of each ACL bundleACL bundle
••
Individualize the surgical procedure for each Individualize the surgical procedure for each patientpatient
Am J Sports Medicine, 2011Karlsson, Irrgang, van Eck, Samuelsson, Mejia, FuAm J Sports Medicine, 2011Am J Sports Medicine, 2011KarlssonKarlsson, , IrrgangIrrgang, van Eck, Samuelsson, Mejia, Fu, van Eck, Samuelsson, Mejia, Fu
••
Restoration of the 2 bundle anatomy and Restoration of the 2 bundle anatomy and function of the ACL does not always require function of the ACL does not always require performing a DB ACL reconstructionperforming a DB ACL reconstruction
The Concept of Anatomic ACL ReconstructionThe Concept of Anatomic ACL ReconstructionThe Concept of Anatomic ACL Reconstruction
Anatomic ACL Reconstruction Anatomic ACL Anatomic ACL ReconstructionReconstruction ≠≠
The Concept of Anatomic ACL Reconstruction can be applied to:
The Concept of Anatomic ACL The Concept of Anatomic ACL Reconstruction can be applied to:Reconstruction can be applied to:
•• SingleSingle--bundle ACL reconstructionsbundle ACL reconstructions
•• DoubleDouble--bundle ACL reconstructionsbundle ACL reconstructions
The Concept of Anatomic ACL Reconstruction can be applied to:
The Concept of Anatomic ACL The Concept of Anatomic ACL Reconstruction can be applied to:Reconstruction can be applied to:
The Concept of Anatomic ACL Reconstruction can be applied to:
The Concept of Anatomic ACL The Concept of Anatomic ACL Reconstruction can be applied to:Reconstruction can be applied to:
•• Augmentation of partial ACL tearsAugmentation of partial ACL tears
AM
PL
PLAM
The Concept of Anatomic ACL Reconstruction can be applied to:
The Concept of Anatomic ACL The Concept of Anatomic ACL Reconstruction can be applied to:Reconstruction can be applied to:
•• ACL remnant preservationACL remnant preservation
The Concept of Anatomic ACL Reconstruction can be applied to:
The Concept of Anatomic ACL The Concept of Anatomic ACL Reconstruction can be applied to:Reconstruction can be applied to:
•• Revision ACL surgery with an intact Revision ACL surgery with an intact vertical graftvertical graft
••
The goal of performing an anatomic ACL The goal of performing an anatomic ACL reconstruction technique is to restore as reconstruction technique is to restore as closely as possible the native ACL anatomy closely as possible the native ACL anatomy
••
It has been proven biomechanically and It has been proven biomechanically and clinically that anatomic ACL reconstructions clinically that anatomic ACL reconstructions better restore rotational stability compared to better restore rotational stability compared to nonnon--anatomic ACL reconstructionsanatomic ACL reconstructions
••
It is hoped, but not yet proven that by better It is hoped, but not yet proven that by better restoring knee kinematics, anatomic ACL restoring knee kinematics, anatomic ACL reconstruction techniques will decrease the reconstruction techniques will decrease the incidence of OA after ACL reconstructionincidence of OA after ACL reconstruction
Why Perform an Anatomic ACL Reconstruction? Why Perform an Anatomic ACL Reconstruction? Why Perform an Anatomic ACL Reconstruction?
Individualized Surgery Individualized Surgery Individualized Surgery
••
Every knee is different so every patient Every knee is different so every patient should not get the same operationshould not get the same operation
••
Surgical technique dictated by:Surgical technique dictated by:ACL injury pattern (complete tear, partial ACL injury pattern (complete tear, partial tear, intact remnants)tear, intact remnants)Graft choice and preparation influenced by Graft choice and preparation influenced by the size of the native ACL attachment sites the size of the native ACL attachment sites Degree of rotational instability (SB Degree of rotational instability (SB vsvs
DB)DB)
••
When anatomic ACL reconstructions are When anatomic ACL reconstructions are individualized to the size, shape and individualized to the size, shape and orientation of the patientorientation of the patient’’s native ACL, SB s native ACL, SB and DB reconstructions yield similar and DB reconstructions yield similar subjective and objective resultssubjective and objective results
••
Subjective IKDC: DB = 93, SB = 93Subjective IKDC: DB = 93, SB = 93
••
Negative Pivot shift DB = 92%, SB = 90%Negative Pivot shift DB = 92%, SB = 90%
Where to Place the Tunnels?Where to Place the Tunnels?Where to Place the Tunnels?
Where to Place the Tunnels?Where to Place the Tunnels?Where to Place the Tunnels?
••
Anatomic ACL graft placement is critical to the Anatomic ACL graft placement is critical to the success and clinical outcome of ACL success and clinical outcome of ACL reconstructionreconstruction
••
NonNon--anatomic tunnel placement is the most anatomic tunnel placement is the most common technical error leading to recurrent common technical error leading to recurrent instability and a failed ACL reconstructioninstability and a failed ACL reconstruction
••
Placement of the ACL femoral tunnel is Placement of the ACL femoral tunnel is especially important because the length and especially important because the length and tension of the ACL replacement graft is most tension of the ACL replacement graft is most influenced by the position of the femoral tunnelinfluenced by the position of the femoral tunnel
0
10
20
30
40
50
60
70
80
90
100
Nonanatomic TunnelPlacement
Associatedlaxity/Malalignment
Inadequate graft Fixation failure Other
Noyes and Barber-Westin (2001) O’Neill (2004) Carson (2004)Ferretti (2006) Garafalo (2006) Salmon (2006)Ahn (2008) Diamantopoulos (2008) MARS Group (2010)Trojani (2011) Danish ACL Registry (2012)
Technical Errors in ACL SurgeryTechnical Errors in ACL SurgeryTechnical Errors in ACL Surgery
100
7877
71
1009193
96
58
68
90
63
00 0
7
0 0 0 0 0
13
29
47 7
105
85
9 77
17
0 0 000 0 0 0 0 0 0 0 0 0 0 05
Matched Tibial and Femoral Tunnel Positions for SB ACL Reconstruction Matched Matched TibialTibial and Femoral Tunnel and Femoral Tunnel
Positions for SB ACL ReconstructionPositions for SB ACL Reconstruction
High AMHigh AM
PLPL
High AM
PL
••
Posterior Posterior tibialtibial
tunnel + tunnel + ““high AMhigh AM””
femoral tunnel = femoral tunnel = vertical ACL graftvertical ACL graft
••
Vertical ACL graft may control AP translation but often Vertical ACL graft may control AP translation but often fails to control the combined motions of anterior fails to control the combined motions of anterior tibialtibial
translation and internal translation and internal tibialtibial
rotation (pivot shift)rotation (pivot shift)
PL – High AM ACL Graft PlacementPL PL –– High AM ACL Graft PlacementHigh AM ACL Graft Placement
Femoral Tunnel AngleFemoral Tunnel Angle
AMAM
AMAM
Matched Tibial and Femoral Tunnel Positions for SB ACL Reconstruction Matched Matched TibialTibial and Femoral Tunnel and Femoral Tunnel
Positions for SB ACL ReconstructionPositions for SB ACL Reconstruction
AM
AM
Matched Tibial and Femoral Tunnel Positions for SB ACL Reconstruction Matched Matched TibialTibial and Femoral Tunnel and Femoral Tunnel
Positions for SB ACL ReconstructionPositions for SB ACL Reconstruction
PLPL
PLPL
PL
PL
Matched Tibial and Femoral Tunnel Positions for SB ACL Reconstruction Matched Matched TibialTibial and Femoral Tunnel and Femoral Tunnel
Positions for SB ACL ReconstructionPositions for SB ACL Reconstruction
CenterCenter
CenterCenterCenter
Center
Where to Place the Tunnels?Where to Place the Tunnels?Where to Place the Tunnels?
••
For anatomic singleFor anatomic single--bundle ACL reconstruction bundle ACL reconstruction the center of the native ACL femoral and the center of the native ACL femoral and tibialtibial
attachment sites are chosen as the position for attachment sites are chosen as the position for the ACL bony tunnelsthe ACL bony tunnels
••
Biomechanical studies have demonstrated that a Biomechanical studies have demonstrated that a SB ACL graft placed at the center of the native SB ACL graft placed at the center of the native ACL femoral and ACL femoral and tibialtibial
attachment sites is more attachment sites is more
effective at controlling anterior effective at controlling anterior tibialtibial
translation translation and the combined motions of anterior and the combined motions of anterior tibialtibial
translation and internal translation and internal tibialtibial
rotation (simulated rotation (simulated pivot shift test) and restores knee kinematics pivot shift test) and restores knee kinematics more closely to that of the normal knee more closely to that of the normal knee compared to isometriccompared to isometric””
ACL femoral tunnel ACL femoral tunnel
placement, other anatomic ACL tunnel placement, other anatomic ACL tunnel placements, or techniques that have traditionally placements, or techniques that have traditionally restored predominantly the AM bundle fibers.restored predominantly the AM bundle fibers.
Center-to-Center ACL Graft PlacementCenterCenter--toto--Center ACL Graft PlacementCenter ACL Graft Placement
••
MIDMID--MID position provided the best stability and more MID position provided the best stability and more closely restored normal knee kinematicsclosely restored normal knee kinematics
••
MIDMID--MID had similar results as a DB reconstructionMID had similar results as a DB reconstruction
KSSTA, 2010KSSTA, 2010
Anatomic ACL Reconstruction: What Surgical Techniques Do We Use to Get There? Anatomic ACL Reconstruction: What Surgical Anatomic ACL Reconstruction: What Surgical Techniques Do We Use to Get There?Techniques Do We Use to Get There?
••
YES!YES!••
Independent femoral and Independent femoral and tibialtibial
tunnelstunnels
••
Longer femoral tunnel lengths more easily obtainedLonger femoral tunnel lengths more easily obtained
Outside-In Drilling?OutsideOutside--In Drilling?In Drilling?
••
YES!YES!••
Independent femoral and Independent femoral and tibialtibial
tunnelstunnels
••
Potential for shorter femoral tunnel lengthsPotential for shorter femoral tunnel lengths
Drilling through a medial portal?Drilling through a medial portal?Drilling through a medial portal?
••
No!No!••
Femoral tunnel position dependent on the Femoral tunnel position dependent on the tibialtibial
tunnel positiontunnel position••
Posterior Posterior tibialtibial
tunnel position tunnel position --
““High AMHigh AM””
femoral tunnel position = vertical ACL graftfemoral tunnel position = vertical ACL graft
Transtibial Drilling?TranstibialTranstibial Drilling?Drilling?
High AMHigh AM
PLPL
••
Cadaveric study: ACL reconstruction Cadaveric study: ACL reconstruction performed performed arthroscopicallyarthroscopically
using using transtibialtranstibial
and and tibialtibial
tunnel independent techniquestunnel independent techniques••
TranstibialTranstibial
guide pin 7.9 mm from the center of guide pin 7.9 mm from the center of
the ACLthe ACL••
TibialTibial
tunnel independent guide pin 1.9 mm tunnel independent guide pin 1.9 mm
from the center of the ACLfrom the center of the ACL
••
HighHigh--resolution MRI and 3D modeling techniques resolution MRI and 3D modeling techniques used to study 8 patients who underwent arthroscopic used to study 8 patients who underwent arthroscopic ACL reconstruction using a ACL reconstruction using a transtibialtranstibial
technique and technique and
8 patients using a 8 patients using a tibialtibial
tunnel independent tunnel independent techniquetechnique
••
TranstibialTranstibial
tunnel technique placed the center of the tunnel technique placed the center of the tunnel 9 mm from the center of the ACLtunnel 9 mm from the center of the ACL
••
TibialTibial
tunnel independent technique placed the tunnel independent technique placed the center of the tunnel 3 mm from the center of the ACLcenter of the tunnel 3 mm from the center of the ACL
••
The clock face reference has often been used The clock face reference has often been used to specify ACL femoral tunnel placement to specify ACL femoral tunnel placement
The Clock Face ReferenceThe Clock Face ReferenceThe Clock Face Reference
Limitations of the Clock Face Reference for ACL Femoral Tunnel Position
Limitations of the Clock Face Reference Limitations of the Clock Face Reference for ACL Femoral Tunnel Positionfor ACL Femoral Tunnel Position
••
It ignores the depth of the notchIt ignores the depth of the notch••
There is no standard location for the 3 There is no standard location for the 3 and 9 oand 9 o’’
positions of the clock facepositions of the clock face
••
This method does not rely on any This method does not rely on any recognized anatomic landmarksrecognized anatomic landmarks
••
The clock reference cannot be used when The clock reference cannot be used when viewing the ACL femoral attachment site viewing the ACL femoral attachment site through the AM portalthrough the AM portal
••
The clock will tell a different time depending on The clock will tell a different time depending on the frame of reference! the frame of reference!
••
The clock face reference has little role to play The clock face reference has little role to play when performing anatomic ACL reconstructionwhen performing anatomic ACL reconstruction
The Clock Face ReferenceThe Clock Face ReferenceThe Clock Face Reference
The Keys to Performing Anatomic ACL Surgery The Keys to Performing Anatomic ACL Surgery The Keys to Performing Anatomic ACL Surgery
••
Portals: Portals: Use 3 portalsUse 3 portals
••
Footprint:Footprint: Identify remnants of the native ACL Identify remnants of the native ACL footprint footprint
••
Osseous ridges:Osseous ridges: Identify the lateral Identify the lateral intercondylarintercondylar
ridge ridge
••
ACL Ruler:ACL Ruler: Used to determine the shallowUsed to determine the shallow-- deep position of the ACL femoral tunneldeep position of the ACL femoral tunnel
••
Fluoroscopy: Fluoroscopy: Most accurate method for both Most accurate method for both femoral and femoral and tibialtibial
tunnel placementtunnel placement
PortalsPortalsPortals
••
3 portal technique3 portal technique••
AnterolateralAnterolateral
(viewing (viewing
portal)portal)••
AnteromedialAnteromedial
(viewing (viewing
portal)portal)••
Accessory medial Accessory medial portal (working portal)portal (working portal)
••
Use of 3 portals allows the ACL femoral Use of 3 portals allows the ACL femoral attachment site to be viewed attachment site to be viewed ““face onface on””
••
Allows the surgeon to look and work in the Allows the surgeon to look and work in the same directionsame direction
3 Portal Technique3 Portal Technique3 Portal Technique
AnteromedialAnteromedial Portal ViewPortal ViewAnterolateralAnterolateral Portal ViewPortal View
Accessory Medial Portal PlacementAccessory Medial Portal PlacementAccessory Medial Portal Placement
•
Accessory medial portal located as low as possible to minimize instrument crowding
•
The medial -
lateral position of the accessory medial portal determines the ACL femoral tunnel length
••
A more medial placement of the accessory medial A more medial placement of the accessory medial portal results in a shorter femoral tunnel length portal results in a shorter femoral tunnel length and a more circularand a more circular--shaped tunnelshaped tunnel
apertureaperture
Accessory Medial Portal PlacementAccessory Medial Portal PlacementAccessory Medial Portal Placement
••
A more lateral placement of the accessory medial A more lateral placement of the accessory medial portal results in a longer femoral tunnel length and portal results in a longer femoral tunnel length and a more ellipticala more elliptical--shaped tunnel apertureshaped tunnel aperture
Accessory Medial Portal PlacementAccessory Medial Portal PlacementAccessory Medial Portal Placement
Femoral Footprint Femoral Footprint Femoral Footprint
••
Identify remnants of the native ACL (donIdentify remnants of the native ACL (don’’t t do do notchplastynotchplasty
initially!)initially!)
Femoral Footprint Femoral Footprint Femoral Footprint
••
Estimate the center of the footprint and Estimate the center of the footprint and mark with a mark with a microfracturemicrofracture
awlawl
Femoral Footprint Femoral Footprint Femoral Footprint
••
The true center of the footprint can be more The true center of the footprint can be more accurately determined using an ACL ruler accurately determined using an ACL ruler
Femoral Footprint Femoral Footprint Femoral Footprint
ACL RidgesACL RidgesACL Ridges
••
Lateral Lateral intercondylarintercondylar
ridgeridge
••
Lateral bifurcate ridgeLateral bifurcate ridge
The ACL Femoral Attachment Site is Defined by 2 Bony Ridges:
The ACL Femoral Attachment Site The ACL Femoral Attachment Site is Defined by 2 Bony Ridges:is Defined by 2 Bony Ridges:
••
Lateral Lateral intercondylarintercondylar
ridge is present in 88% ridge is present in 88% of subof sub--acute and chronic ACL deficient kneesacute and chronic ACL deficient knees
Does the lateral Does the lateral intercondylarintercondylar ridge ridge disapperdisapper in ACL deficient patients? in ACL deficient patients? van Eck et al, ESSTA, 2010van Eck et al, ESSTA, 2010
Anatomy of the ACL Femoral Attachment SiteAnatomy of the ACL Femoral Attachment SiteAnatomy of the ACL Femoral Attachment Site
••
Bifurcate ridge is present in 48% of subBifurcate ridge is present in 48% of sub--acute acute and chronic ACL deficient kneesand chronic ACL deficient knees
••
The lateral The lateral intercondylarintercondylar
ridge is the key to ridge is the key to anatomic ACL femoral tunnel placement as anatomic ACL femoral tunnel placement as the native ACL always lies inferior to this ridgethe native ACL always lies inferior to this ridge
••
The distance from the lateral The distance from the lateral intercondylarintercondylar ridge to the inferior ridge to the inferior articulararticular
cartilage margin cartilage margin
represents the highrepresents the high--low position of the tunnellow position of the tunnel
50%
ACL RidgesACL RidgesACL Ridges
••
Anatomical studies have demonstrated that the Anatomical studies have demonstrated that the center of the ACL femoral attachment site is 7.3 center of the ACL femoral attachment site is 7.3 ––
8.6 mm superior to the border of the inferior 8.6 mm superior to the border of the inferior articulararticular
cartilagecartilage
7.3 – 8.6 mm
ACL RidgesACL RidgesACL Ridges
••
The center of the ACL femoral attachment site The center of the ACL femoral attachment site is 1.7 mm deep (proximal) to the lateral is 1.7 mm deep (proximal) to the lateral bifurcate ridge bifurcate ridge (Ziegler et al, AJSM 2011)(Ziegler et al, AJSM 2011)
ACL RidgesACL RidgesACL Ridges
ACL RulerACL RulerACL Ruler
••
Measure from the deep (proximal) Measure from the deep (proximal) articulararticular cartilage border to the shallow (distal) cartilage border to the shallow (distal) articulararticular
cartilage border and mark at 50% from the deep cartilage border and mark at 50% from the deep borderborder
ACL RulerACL RulerACL Ruler
Intraoperative FluoroscopyIntraoperativeIntraoperative FluoroscopyFluoroscopy
••
Most accurate method to determine Most accurate method to determine tunnel placementtunnel placement
Intraoperative FluoroscopyIntraoperativeIntraoperative FluoroscopyFluoroscopy
Intraoperative FluoroscopyIntraoperativeIntraoperative FluoroscopyFluoroscopy
••
In order to get useful information you In order to get useful information you must obtain good lateral imagesmust obtain good lateral images
Intraoperative Fluoroscopy: A Simple Way to Improve ACL Tunnel Placement IntraoperativeIntraoperative Fluoroscopy: A Simple Fluoroscopy: A Simple
Way to Improve ACL Tunnel PlacementWay to Improve ACL Tunnel Placement
••
Available in most ORAvailable in most OR’’s so there is no added s so there is no added equipment costequipment cost
••
Can detect position differences of 1 Can detect position differences of 1 ––
2 mm2 mm
••
Images can be downloaded and saved on Images can be downloaded and saved on an image capture unit and become a an image capture unit and become a permanent part of the patientpermanent part of the patient’’s records record
••
Serves as a quality control and narrows SD Serves as a quality control and narrows SD of ACL tunnel placementof ACL tunnel placement
••
The femoral tunnel position can be specified The femoral tunnel position can be specified using the Bernardusing the Bernard--HertelHertel
gridgrid
Intraoperative FluoroscopyIntraoperativeIntraoperative FluoroscopyFluoroscopy
Advantages of the Radiographic Quadrant MethodAdvantages of the Radiographic Quadrant MethodAdvantages of the Radiographic Quadrant Method
••
Easy to useEasy to use
••
Reproducible Reproducible
••
Independent of the knee shape and Independent of the knee shape and sizesize
••
Independent of the distance between Independent of the distance between the knee and xthe knee and x--ray beamray beam
••
Can be used for documentationCan be used for documentation
Summary of Radiographic Grid MeasurementsSummary of Radiographic Grid MeasurementsSummary of Radiographic Grid Measurements
Study AMBDepth
PLB Depth
Ave 50% Depth
AMBHeight
PLBHeight
Ave 50%Height
Bernard-Hertel
(1997), N = 10 24.8 28.5
Yamamoto (2004), N = 10 25 29 27 16 42 29
Colombet
(2006), N = 7 26.4 32.3 29.4 25.3 47.6 36.5
Zantop
(2008), N = 20 18.5 29.3 23.9 22.3 53.6 38.0
Tsukada
(2008), N = 36 25.9 34.8 30.4 17.8 42.1 30.0
Lorenz (2009), N = 12 21 27 24 22 45 34
Forsythe (2010), N = 8 21.7 35.1 28.4 33.2 55.3 44.3
Pietrini
(2010), N = 12 21.6 28.9 25.3 14.6 42.3 28.5
Iriuchishima
(2010), N = 15 15 32 23.5 26 52 39
Weighted averages 22.0 31.6 26.7 21.0 46.8 33.5
••
Using data from these published studies, a Using data from these published studies, a weighted average position for the center of weighted average position for the center of the ACL femoral attachment site can be the ACL femoral attachment site can be calculated. calculated.
••
This calculation reveals that the center of This calculation reveals that the center of the ACL femoral attachment site is located the ACL femoral attachment site is located at a point which is 27% along at a point which is 27% along BlumensaatBlumensaat’’ss
line and 34% of the height of the line and 34% of the height of the intercondylarintercondylar
notch.notch.
Radiographic Quadrant MeasurementsRadiographic Quadrant MeasurementsRadiographic Quadrant Measurements
28%
37%
37%
••
If present, identify the native ACL footprintIf present, identify the native ACL footprint
How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel
How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel
••
Measure the length of the femoral attachment Measure the length of the femoral attachment site along its long axis and mark at 50%site along its long axis and mark at 50%
••
The highThe high--low position is midway between the low position is midway between the superior and inferior borders of the footprintsuperior and inferior borders of the footprint
••
If there are no remnants of the native ACL If there are no remnants of the native ACL femoral footprint present identify the lateral femoral footprint present identify the lateral intercondylarintercondylar
ridgeridge
How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel
••
Use an ACL ruler to measure from the deep Use an ACL ruler to measure from the deep border of the ACL cartilage margin to the border of the ACL cartilage margin to the shallow cartilage border and mark at 50%shallow cartilage border and mark at 50%
How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel
••
The highThe high--low position of the femoral tunnel is low position of the femoral tunnel is midway between the lateral midway between the lateral intercondylarintercondylar
ridge and the border of the inferior ridge and the border of the inferior articulararticular cartilagecartilage
How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel
••
If the footprint or ridges are not clearly defined If the footprint or ridges are not clearly defined or in revision cases fluoroscopy is invaluableor in revision cases fluoroscopy is invaluable
How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel
How to Drill an Anatomic Femoral Tunnel How to Drill an Anatomic Femoral Tunnel How to Drill an Anatomic Femoral Tunnel
••
The femoral tunnel position can be specified The femoral tunnel position can be specified using the Bernardusing the Bernard--HertelHertel
gridgrid
28%
37%
37%
••
Drill the ACL femoral tunnel at the center Drill the ACL femoral tunnel at the center of the ACL femoral attachment siteof the ACL femoral attachment site
How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel How to Drill an Anatomic ACL Femoral Tunnel
How to Drill an Anatomic ACL Tibial Tunnel How to Drill an Anatomic ACL How to Drill an Anatomic ACL TibialTibial Tunnel Tunnel
••
AP position: 1 AP position: 1 ––
2 mm anterior to the posterior 2 mm anterior to the posterior margin of the LMmargin of the LM
••
MedialMedial--lateral: slightly medial to the midline lateral: slightly medial to the midline
1 – 2 mm
••
Due to the lack of definitive Due to the lack of definitive bony landmarks, fluoroscopy is very helpful to determine tibial
guide pin placement
How to Drill an Anatomic ACL Tibial Tunnel How to Drill an Anatomic ACL How to Drill an Anatomic ACL TibialTibial Tunnel Tunnel
Amis – Jakob LineAmis Amis –– JakobJakob LineLine
0%
100%43%
Medial Joint LineMedial Joint Line
Posterior Tibial Guide Pin PlacementPosterior Posterior TibialTibial Guide Pin PlacementGuide Pin Placement
Posterior Tibial Guide Pin PlacementPosterior Posterior TibialTibial Guide Pin PlacementGuide Pin Placement
55%55%
Posterior Tibial Guide Pin PlacementPosterior Posterior TibialTibial Guide Pin PlacementGuide Pin Placement
43%43%
Anterior Tibial Guide Pin PlacementAnterior Anterior TibialTibial Guide Pin PlacementGuide Pin Placement
Anterior Tibial Guide Pin PlacementAnterior Anterior TibialTibial Guide Pin PlacementGuide Pin Placement
Anterior Tibial Guide Pin PlacementAnterior Anterior TibialTibial Guide Pin PlacementGuide Pin Placement
SummarySummarySummary
••
““AnatomicAnatomic””
SB ACL reconstruction refers to a SB SB ACL reconstruction refers to a SB reconstruction in which the femoral and reconstruction in which the femoral and tibialtibial
bone bone
tunnels are placed at the center of the native tunnels are placed at the center of the native femoral and femoral and tibialtibial
attachment sitesattachment sites
••
Use 3 portals and view the ACL femoral attachment Use 3 portals and view the ACL femoral attachment site through the site through the anteromedialanteromedial
portalportal
••
Use one or all of the following to determine the Use one or all of the following to determine the center of the native ACL femoral attachment site:center of the native ACL femoral attachment site:
Remnants of the native ACLRemnants of the native ACLLateral Lateral intercondylarintercondylar ridgeridgeACL rulerACL rulerFluroscopyFluroscopy