The Knee Region Flashcards
What are the primary functions of the knee joint?
Support body weight.
Facilitate locomotion.
Name the joints that make up the knee complex.
Tibiofemoral joint (synovial, modified hinge).
Patellofemoral joint (synovial, saddle).
Proximal tibiofibular joint (synovial, plane).
What are the bony landmarks of the distal femur (anterior view)?
Adductor tubercle.
Medial and lateral epicondyles.
Lateral buttress wall.
Patellar surface.
What are the bony landmarks of the distal femur (posterior view)?
Linea aspera.
Medial and lateral supracondylar lines.
Medial and lateral condyles.
Popliteal surface.
Adductor tubercle.
Intercondylar fossa.
What are the bony landmarks of the proximal tibia?
Medial and lateral tibial condyles.
Tibial plateau.
Intercondylar eminence (medial and lateral tubercles).
Tibial tuberosity.
Anterior tibial crest.
Describe the menisci of the knee.
Medial meniscus: C-shaped, less mobile, more prone to injury.
Lateral meniscus: O-shaped, more mobile.
Functions: Deepen tibial articular surface, act as shock absorbers, conform to femoral condyles.
What is the clinical relevance of the menisci?
Meniscus tears may result in mechanical symptoms such as clicking, catching, locking, or giving way.
Describe the ligaments of the knee joint.
Lateral Collateral Ligament (LCL): Limits varus movement.
Medial Collateral Ligament (MCL): Limits valgus movement.
Anterior Cruciate Ligament (ACL): Limits anterior translation of the tibia.
Posterior Cruciate Ligament (PCL): Limits posterior translation of the tibia.
What is the role of the patellofemoral joint?
Functions as a synovial saddle joint between the patellar and femoral articular surfaces.
Enhances knee extension mechanics.
Name the soft tissues associated with the knee.
Bursae: Suprapatellar, prepatellar, infrapatellar, pes anserine, semimembranosus.
Infrapatellar fat pad.
What factors contribute to knee joint stability?
Ligamentous tension (e.g., ACL, PCL, MCL, LCL).
Locking mechanism (medial rotation of femur on tibia during extension).
Meniscal congruency.
Muscle support.
What is the Q-angle, and why is it important?
The angle between the quadriceps muscles (especially rectus femoris) and the patellar tendon.
Measured as the angle between the line from the ASIS to the patella and the line from the patella to the tibial tuberosity.
Represents the direction of quadriceps muscle force.
What are the clinical implications of patellofemoral pain (PFP)?
Pain around or behind the patella, aggravated by activities such as squatting, running, or stair climbing.
What are the movements of the tibiofemoral joint?
Flexion/Extension (sagittal plane).
Medial/Lateral rotation (transverse plane).
What is the function of the proximal tibiofibular joint?
Allows small rotational movements during ankle dorsiflexion/plantarflexion.
Classified as a synovial plane joint.
What is the clinical significance of genu varum and genu valgum?
Genu varum: Bow-legged alignment, increased stress on medial knee structures.
Genu valgum: Knock-knee alignment, increased stress on lateral knee structures.
How does the patellofemoral joint maintain stability?
Patella position (alta or baja).
Lateral femoral buttress wall.
Ratio of VMO (vastus medialis obliquus) to VL (vastus lateralis) strength.
Tightness of lateral retinaculum.
What are the active movements of the knee?
Flexion
Extension
Medial rotation (of tibia on femur)
Lateral rotation (of tibia on femur)
What is the clinical significance of active and passive insufficiency?
Active insufficiency: When a muscle cannot contract fully to produce motion at all the joints it crosses.
Passive insufficiency: When a muscle cannot stretch enough to allow full range of motion at all the joints it crosses.
What are the knee extensors, and what is their innervation?
Rectus Femoris
Vastus Intermedius
Vastus Medialis
Vastus Lateralis
Innervation: Femoral nerve (L2-L4).
What is the proximal and distal attachment of Rectus Femoris?
Proximal Attachment:
Long head: AIIS.
Short head: Ilium, superior to acetabulum.
Distal Attachment: Quadriceps femoris tendon.
Name the knee flexors and their nerve supply.
Hamstrings (Biceps Femoris, Semitendinosus, Semimembranosus): Sciatic nerve (L5-S2).
Sartorius: Femoral nerve (L2-L3).
Gracilis: Obturator nerve (L2-L3).
Gastrocnemius: Tibial nerve (S1-S2).
Plantaris: Tibial nerve (S1-S2).
What is the function of the Popliteus muscle?
Stabilizes the knee joint by resisting lateral rotation of the tibia on the femur.
Unlocks the knee joint by laterally rotating the femur on a fixed tibia.
What are the boundaries of the popliteal fossa?
Laterally: Biceps femoris, lateral head of gastrocnemius.
Medially: Semimembranosus, semitendinosus, medial head of gastrocnemius.
Floor: Popliteal surface of femur.
Roof: Fascia and skin.
What are the contents of the popliteal fossa?
Popliteal artery and vein.
Common peroneal and tibial nerves.
Lymph nodes and fat.
Which muscles medially rotate the tibia on the femur?
Semitendinosus
Semimembranosus
Sartorius
Popliteus
Which muscle laterally rotates the tibia on the femur?
Biceps Femoris.
What is the function of the Gastrocnemius muscle at the knee?
Flexes the knee.
Plantarflexes the foot.
What are the attachments and action of the Gracilis muscle?
Proximal Attachment: Pubis and ischium.
Distal Attachment: Medial surface of proximal tibia.
Action: Adducts the thigh at the hip and flexes the leg at the knee.
What is the action of the Tensor Fascia Lata (TFL) at the knee?
Stabilizes the knee joint.
Weak abductor and internal rotator.
What is the nerve supply and action of the Plantaris muscle?
Nerve Supply: Tibial nerve (S1-S2).
Action: Flexes the knee and plantarflexes the foot.
List the muscles that flex the knee.
Biceps Femoris
Semitendinosus
Semimembranosus
Sartorius
Gracilis
Gastrocnemius
Plantaris
What is the function of the quadriceps femoris group at the knee?
Extends the leg at the knee joint.
