REGION: KNEE

Studying anatomy & physiology grouped by regions of the body.

WORK IN PROGRESS…LAST UPDATE 01.21.2020

Bony Landmarks of the Femur

Femoral head	Intercondyloid fossa
Femoral neck	Linea aspera
Greater trochanter	Gluteal line
Lesser trochanter	Fovea
Trochanteric fossa	Adductor tubercle
Epiphyseal line	Quadratus tubercle
Intertrochanteric line	Intertrochanteric crest
Femoral shaft	Pectineal line
Lateral epicondyle	Spiral line
Medial epicondyle	Medial supracondylar line
Lateral condyle	Lateral supracondylar line
Medial condyle	Intercondylar line
Patellar trochlea	Popliteal surface

Features of the Patella

Patellar ligament	Prepatellar bursa
Infrapatella fold	Subcutaneous & deep infrapatellar bursae
Infrapatellar fat

Bony Landmarks of the Tibia

Tibial tuberosity	Superior articular surfaces: medial & lateral
Tibial head	Tibial plateau
Medial tibial condyle	Gerdy's tubercle
Lateral tibial condyle	Oblique line
Intercondylar eminence	Anterior crest
Medial intercondylar tubercle	Popliteal line
Lateral intercondylar tubercle	Fibular notch
Anterior intercondylar area	Medial malleolus
Posterior intercondylar area	Proximal tibiofibular joint
Interosseus membrane	Distal tibiofibular joint

Muscles

• Rectus femoris.
• Vastus lateralis.
• Vastus intermedius.
• Vastus medialis.
• All insert into tibial tuberosity via patellar ligament. Anterior stabilize knee joint.
• Lateral stabilizer: iliotibial band.
• Medial stabilizer: SGT.
• Posterior stabilizer: popliteus.

Joints

• Tibiofemoral (knee) joint.

Ligaments/Tendons

Ligaments: Medial Collateral Ligament, MCL

• MCL detail page.
• O: femoral medial epicondyle.
• I: two insertions. Conjoins into semimembranosus tendon & posteromedial crest of tibia.
• N: medial articular nerve (branch of the saphenous nerve).
• V: branches of superior and inferior genicular arteries.
• A: reinforce medial portion of articular capsule of knee; stabilize medial knee; primary static stabilizer. Limits anterior movement of tibia and prevents hyperextension. Superficial, sMCL, MCL is a knee valgus stabilizer. Deep, dMCL, MCL is rotational stabilizer.

Ligaments: Lateral Collateral Ligament, LCL

• LCL detail page.
• O: lateral epicondyle of femur.
• I: fibula head.
• N: fibers of tibial nerve.
• V: superolateral and inferolateral geniculate arteries.
• A: Controls the amount of lateral movement of the tibia. Stabilizes lateral knee especially varus stress, and posterolateral tibial rotation relative to femur. Stabilize anterior/posterior tibial translation.

Ligaments: Anterior Cruciate Ligament, ACL

• ACL detail page.
• O: posteromedial corner of medial aspect of femoral condyle in the intercondylar notch.
• I: anterior to the intercondylar eminence of the tibia.
• N: fibers from the posterior articular branches of tibial nerve.
• V: middle geniculate artery.
• A: Controls rotation and forward movement of the tibia. Responsible for 85% of force to control/limit tibial forward translation. Attenuates tibial medial and lateral rotation, and knee varus-valgus forces.

Ligaments: Posterior Cruciate Ligament, PCL

• PCL detail page.
• O: posterior tibial sulcus below articular surface.
• I: anterolateral medial femoral condyle.
• N: tibial nerve.
• V: middle geniculate artery.
• A: Controls the amount of backward movement of the tibia. Controls tibial posterior translation. Prevent hyperflexion/sliding.

Vascular Supply

• Superior medial genicular artery
• Inferior medial genicular artery
• Popliteal artery
• Anterior tibial artery
• Posterior tibial artery

Innervation

• Muscles and tendons have sensory receptors.
• Skin does not have somatic motor neuron innervation.

Clinical/Pathology

Q Angle

• The alignment of the femur and tibial. Deviations may indicate risk for ACL tears.
• Genu varum. Bow-leg. If the knee is pointing laterally, that is knee varus.
• Tibial deviations from midline beyond acceptable range: unequal weight distribution; unequal wear/tear; genu varum; genu valgum.

Anterior Drawer Test

• For ACL.

Patellar Reflex Test

Adduction Varus Stress Test (LCL)

External rotation-recurvatum test (LCL)

Reverse pivot shift sign of Jakob, Hassler, and Stäubli (LCL)

Dial test (LCL)

Unhappy Triad: MCL, Medial Meniscus, ACL

• “Blown Knee”.

Osteoarthritis

• Wear/tear arthritis.

Rheumatoid Arthritis

• Autoimmune.

Bone Spurs

Abnormal Patella Tracking

• Chondromalacia (cartilage breakdown).

Meniscal tears: LCL

• Non-contact hyperextension.
• Non-contact varus stress.
• Contact blow to anteromedial and posterolateral corners.

Meniscal tears: PCL

• Contact blow to proximal tibia when knee is flexed (“dashboard” injury).
• Hyperflexion with foot plantar-flexed.
• Hyperextension.

Other Features

Detailed Studies

Notes

• Muscles: rectus femoris, vastus lateralis, vastus intermedius, vastus medialis.
• All insert into tibial tuberosity via patellar ligament.
• Anterior: stabilize knee joint.
• Lateral stabilizer: iliotibial band.
• Medial stabilizer: SGT (sartorius, gracilis, semi-tendinosus) or Pes Anserinus.
• Posterior stabilizer: popliteus.

References

• https://www.physio-pedia.com/Anterior_Cruciate_Ligament_(ACL)
• http://www.wheelessonline.com/ortho/anatomy_of_acl
• https://www.physio-pedia.com/Posterior_Cruciate_Ligament_Injury
• http://www.wheelessonline.com/ortho/anatomy_of_the_posterior_cruciate_ligament
• https://www.orthobullets.com/knee-and-sports/3011/lcl-injury-of-the-knee
• http://www.wheelessonline.com/ortho/medial_collateral_ligament
• https://www.ncbi.nlm.nih.gov/books/NBK507780/

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.