Introduction A diarthrodial joint that allows simultaneous rotation and translation Overview of Knee Ligament Function Ligament Primary function Secondary function Anterior Cruciate Ligament (ACL) Resists anterolateral displacement of the tibia on the femur Resists varus displacement at 0 degrees of flexion Posterior Cruciate Ligament (PCL) Resists posterior tibial displacement, especially at 90 degrees of flexion Resists varus displacement at 0 degrees of flexion Lateral Collateral Ligament (LCL) Resists varus displacement at 30 degrees of flexion Resists posterolateral rotatory displacement with flexion that is less than approximately 50 degrees Popliteofibular Ligament / Posterior Lateral Corner (PLC) Resists posterolateral rotation of the tibia on the femur Resists varus angulation and posterior displacement of the tibia on the femur Medial Collateral Ligament (MCL) Resists valgus angulation Works in concert with ACL to provide restraint toaxial rotation Lateral Structures of Knee Layer 1 Iliotibial tract, biceps femoris Common peroneal nerve lies between layer I and II Layer 2 Patellar retinaculum Layer 3 Superficial: LCL, fabellofibular ligament, ALL Lateral geniculate artery runs between deep and superficial layer Deep: Arcuate ligament, coronary ligament, popliteus tendon, popliteofibular ligament, capsule Medial Structures of Knee Layer 1 Sartorius and fascia (patellar retinaculum) gracilis, semitendinosis, and saphenous nerve run between layer 1 and 2 Layer 2 Semimembranosus, superficial MCL, MPFL, posterior oblique ligament Layer 3 Deep MCL, capsule, coronary ligament ACL Function prevents anterior translation of the tibia relative to the femur Anatomy extrasynovial but intracapsular origin lateral femoral condyle PL bundle originates posterior and distal to AM bundle (on femur) insertion broad and irregular anterior and between the intercondylar eminences of the tibia structure 33mm x 11mm in size two bundles anteromedial fibers are parallel in extension fibers are externally rotated in flexion tight in flexion and loose in extension posterolateral PL bundle prevents pivot shift prevents internal tibial rotation with knee near extension tight in extension, loose in flexion Blood supply middle geniculate artery Innervation contains significant innervation by posterior articular branches of tibial nerve contains mechanoreceptors (Ruffini, Pacini, Golgi tendon organs, free-nerve endings) function of innervation proprioception modulation of quadriceps function Composition 90% Type I collagen 10% Type III collagen Biomechanics tensile strength native ACL 2200 N BPTB 3000N quadrupled hamstring 4000N ACL/PCL bundles ACL PCL Tight in flexion AM AL Tight in extension PL PM PCL Function prevents posterior translation of the tibia relative to the femur PCL and PLC work in concert to resist posterior translation and posterolateral rotatory instability Anatomy extrasynovial but intracapsular origin medial femoral condyle insertion tibial sulcus structure 38mm x 13mm in size two bundles anterolateral shorter, thicker and stronger in double bundle reconstruction, tensioned in mid flexion posteromedial longer, thinner, weaker in double bundle reconstruction, tensioned in extension and high flexion tensioning in extension protects against hyperextension insertions medial intercondylar ridge marks proximal border of femoral insertion medial bifurcate ridge separate the AL from PM bundle variable meniscofemoral ligaments originate from the posterior horn of the lateral meniscus and insert into the substance of the PCL. These include Ligament of Humphrey (anterior to PCL) Ligament of Wrisberg (posterior to PCL) blood supply middle geniculate artery Biomechanics strength: 2500 N (vs posterior translation) LCL (lateral collateral ligament or fibular collateral ligament) Function resists varus angulation works in concert with MCL to provide restraint to axial rotation Anatomy origin on lateral femoral condyle posterior and superior to origin of popliteus path runs superficial to popliteus insertion on the fibula anterior to the popliteofibular ligament on the fibula capsule's most distal extent is just posterior to the fibula structure cord-like Biomechanics tight in extension and lax in flexion strength: 750 N (vs varus stress) PLC (posterolateral corner) Function works synergistically with the PCL to control external rotation and posterior translation Anatomy included structures LCL (295N) popliteus muscle and tendon (680N) popliteofibular ligament (229N) lateral capsule variable arcuate ligament iliotibial band fabellofibular ligament MCL Function resists valgus angulation works in concert with ACL to provide restraint to axial rotation Anatomy origin MFC to medial tibia extending down several centimeters structure two components superficial portion (tibial collateral ligament) lies just deep to gracilis and semitendinosus originates from medial femoral epicondyle and inserts into periosteum of proximal tibia (deep to pes anserinus) the superficial portion of the MCL contributes 57% and 78% of medial stability at 5 degrees and 25 degrees of knee flexion, respectively. the superficial MCL is the primary stabilizer to valgus stress at all angles deep portion (medial capsular ligament) separated from superficial portion by a bursa attaches to medial meniscus (coronary ligament) divided into meniscofemoral and meniscotibial portions posterior fibers of the deep MCL blend with posteromedial capsule and POL the deep MCL and posteromedial capsule act as secondary restraints to valgus stress at full knee extension. Biomechanics strength: 4000 N (vs valgus stress) Posteromedial corner Function important for rotatory stability Anatomy lies deep to MCL formed by insertion of semimembranosus posterior oblique ligament resists valgus load and tibial internal rotation in full extension oblique popliteal ligament posterior capsule Medial patellofemoral ligament (MPFL) Function provide restraint against lateral translation of the patella from 0° to 30° of knee flexion Characteristics low tension throughout flexion-extension (2-10N of force) isometric between 0° and 90°, then becomes slack beyond 90° can withstand 200N before tearing much lower load to failure than ACL (1725N) Anatomy lies in 2nd layer of medial soft tissue complex 2 bundles short oblique bundle, inserts on superior patellar pole inferior straight bundle femoral insertion medial femoral condyle, distal to adductor tubercle and proximal to MCL attachment Schottle's point 1.3mm anterior to posterior femoral diaphyseal cortex 2.5mm distal to posterior origin of medial femoral condyle proximal to the level of the posterior point of Blumensaat's line patellar attachment fan-like structure inserting at junction between proximal-middle thirds of superomedial border of patella Pathoanatomy tears off femoral attachment > patellar attachment some studies show otherwise risk of 2nd dislocation is 13% risk of 3rd dislocation (after 2nd dislocation) is 50% Anterolateral Ligament Function rotational stability Anatomy lies in Layer 3 with LCL characteristics width 7mm at midpoint/near joint line femoral attachment width 8mm tibial attachment width 11mm length 59mm attachments femoral lateral femoral epicondyle tibial midway between Gerdy's tubercle and head of fibula attachments to middle third of lateral meniscus body meniscotibial portion (dot) meniscofemoral portion (asterisk) lateral inferior genicular artery and vein contained between lateral meniscus and ALL at level of joint line NO connections to ITB Pathoanatomy Segond's fracture (associated with ACL rupture) is avulsion fracture of ALL
QUESTIONS 1 of 10 1 2 3 4 5 6 7 8 9 10 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ13.248) Figure A shows the 2 bundles of the ACL dissected from a cadaveric knee off their bony attachments. They are labeled Bundle A and Bundle B, respectively. Which of the following is true? QID: 4883 FIGURES: A Type & Select Correct Answer 1 The tibial attachment of Bundle A is anterior to Bundle B. In extension, Bundle B is loose and Bundle A is tight. 14% (794/5520) 2 The tibial attachment of Bundle A is anterior to Bundle B. In flexion, Bundle B is loose and Bundle A is tight. 66% (3658/5520) 3 The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle B is loose and Bundle A is tight. 6% (311/5520) 4 The tibial attachment of Bundle B is anterior to Bundle A. In flexion, Bundle A is loose and Bundle B is tight. 11% (605/5520) 5 The tibial attachment of Bundle B is anterior to Bundle A. In extension, Bundle A is loose and Bundle B is tight. 2% (107/5520) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review Tested Concept Review Full Topic (OBQ12.257) The function of which of the following structures is to resist internal tibial rotation with the knee in full extension? QID: 4617 Type & Select Correct Answer 1 Anterior cruciate ligament 22% (814/3742) 2 Iliotibial band 9% (346/3742) 3 Popliteus tendon 27% (992/3742) 4 Popliteofibular ligament 9% (327/3742) 5 Posterior oblique ligament 33% (1237/3742) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review Tested Concept Review Full Topic (OBQ12.113) A 28-year-old football player sustains a contact knee injury while being tackled. On physical exam, he has a 1A Lachman, and a normal McMurray test. His posterior drawer, dial, and varus stress tests are normal. He has pain and 5mm opening on valgus stress at 30 degrees of flexion. Which statement is true regarding the injured structure? QID: 4473 Type & Select Correct Answer 1 Resides between layers 1 and 2 on medial side of knee 21% (1286/6268) 2 Inserts onto Gerdy's tubercle 3% (158/6268) 3 Originates slightly posterior and proximal to the medial epicondyle 61% (3826/6268) 4 Courses intraarticularly thru hiatus of lateral meniscus 2% (118/6268) 5 Has an attachment between adductor tubercle and medial epicondyle at Schöttle's point 13% (824/6268) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ10.239) Isolated transection of the posterolateral(PL) bundle of the ACL has what effect on anterior tibial translation and rotatory stability of the knee? QID: 3338 Type & Select Correct Answer 1 Increased tibial translation and rotation at 30 degrees of flexion 55% (1939/3508) 2 Increased tibial translation and rotation at 90 degrees of flexion 12% (417/3508) 3 Increased tibial translation at 30 degrees of flexion and increased rotation at 90 degrees of flexion 21% (739/3508) 4 Increased tibial translation at 90 degrees and negligible effect on rotatory stability 4% (123/3508) 5 Increased tibial translation at 30 degrees and negligible effect on rotatory stability 8% (270/3508) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
All Videos (6) Podcasts (2) ISTA: New Early-Career Webinar Series 2020 The Correct Insert Thickness Restores Maximal Internal-External Rotation of a Medial Stabilized Posterior Cruciate Ligament Retaining TKA During Passive Flexion - Alexander Nedopil Alexander J. Nedopil Recon - Ligaments of the Knee B 3/3/2021 455 views 0.0 (0) Login to View Community Videos Login to View Community Videos ISTA: New Early-Career Webinar Series 2020 In Vivo Knee Kinematics: How Important Are the Roles of Femoral Geometry and the Cruciate Ligaments? - Lauren Smith Lauren Smith Recon - Ligaments of the Knee B 3/3/2021 48 views 0.0 (0) Login to View Community Videos Login to View Community Videos 2019 Orthopaedic Summit Evolving Techniques Evolving Technique Update: Hamstring Harvest: Not Being Left Too Short, Let Me Show You How - S. Clifton Willimon, MD Samuel Willimon Recon - Ligaments of the Knee C 11/20/2020 106 views 0.0 (0) Recon⎜Ligaments of the Knee Recon - Ligaments of the Knee Listen Now 23:13 min 10/18/2019 942 plays 3.9 (8) Question Session⎜Ligament Injuries of the Knee (ft. Dr. Mark Miller) Orthobullets Team Knee & Sports - Ligaments of the Knee Listen Now 17:13 min 11/11/2019 161 plays 3.7 (3) See More See Less
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