Lower limb (knee joint) Flashcards
What are the boundaries of the popliteal fossa?
- Superior (medial): Semitendinosus and demimembranosos
- Superior (lateral): Biceps femoris
- Inferior: 2 heads of gastrocnemius
What are the contents of the popliteal fossa (lateral -medial)?
- Tibial nerve (superficial)
- Popliteal vein
- Popliteal artery (deep)
Other:
- Sural nerve
- Common fibular nervre
- Popliteal lymph nodes
What is the course of the tibial nerve in the popliteal fossa?
The tibial nerve passes straight across the midline of the popliteal fossa and enters the posterior compartment of the leg between the 2 heads of gastrocnemius.
What is the course of the common fibular nerve in the popliteal fossa?
- It follows the lower border of biceps femoris and travels laterally.
- It then winds superficially around the lateral aspects of the head of fibula and passes deep to the head of fibularis longus.
- It divides into the superficial and deep fibular branches here.
What are the articulations of the knee joint?
- Femoral condyles articulate with the tibial condyles
- Patella articulates with the femur
What type of joint is the knee joint?
Synovial hinge joint
What are the attachments of the medial and lateral menisci?
Medial meniscus:
- Intercondylar eminence
- Joint capsule
Lateral meniscus:
- Intercondylar eminence
- Popliteus
Medial and lateral menisci attached to each other anteriorly by the transverse ligament of the knee.
What are the attachments of the synovial membrane?
Superior: Margins of articulating surface of femur
Inferior: Margins of menisci
What are the bursa present in the knee joint?
- Subpopliteal bursa: Reduces friction between popliteal tendon and joint.
- Suprapatella bursa: Reduces friction between quadriceps tendon and joint.
What are the extracapsular ligaments of the knee?
- Medial collateral ligament
- Lateral collateral ligament
- Oblique popliteal ligament
- Patellar ligament
What are the attachments and functions of the medial collateral ligament?
Attachments:
- Distal femur (medial epicondyle)
- Head of tibia
- Capsule
- Medial meniscus
Functions:
- Prevents lateral bending of the knee joint (valgus force)
- Limits full extension of knee
What are the attachments and functions of the lateral collateral ligament?
Attachments:
- Distal femur (lateral epicondyle)
- Head of fibula
Functions:
- Prevents medial bending of the knee joint (varus force)
- Limits full extension of knee
What is the difference between fibres of medial and lateral collateral ligaments?
- Lateral fibres run posteroinferiorly
- Medial fibres run anteroinferiorly
What are the intracapsular ligaments of the knee?
- Anterior curciate ligament
- Posterior cruciate ligament
- Transverse ligament of the knee
What are the attachments and functions of the anterior cruciate ligament?
Attachments:
- Anterior aspects of the intercondylar eminence
- Posteromedial aspects of the lateral femoral condyle
Functions:
- Prevents posterior displacement of the femur on the tibia
What are the attachments and functions of the posterior cruciate ligament?
Attachments:
- Posterior aspects of the intercondylar eminence
- Anterolateral aspects of the medial femoral condyle
Functions:
Prevents anterior dislocation of the femur on the tibia
What are the events that occur during locking?
- Knee becomes fully extended.
- Anterior cruciate ligament becomes taut.
- The femur medially rotates relative to the tibia, on the axis of the anterior cruciate ligament.
- The collateral ligaments tighten.
- Gluteus maximus and tensor fascia latae contract and tighten the iliotibial tract.
What is the function of knee locking?
Allows the tibial plateau to bear the weight of the femur, minimising the need for muscles in weightbearing.
How is the knee unlocked?
Action of popliteus
What is significant about the distal tibiofibular joint?
It is the only fibrous joint in the lower limb.
What are the ligaments of the proximal tibiofibular joint?
Anterior and posterior ligaments of the fibular head.
What are the ligaments of the proximal tibiofibular joint?
Anterior and posterior tibiofibular ligaments
What is the blood supply to the knee joint?
Anastomotic network with branches from:
- Superior genicular artery (medial/lateral) from femoral artery
- Inferior genicular artery (medial/lateral) from popliteal artery
- Circumflex femoral artery from posterior tibial artery
