L12: Bones, ligaments and joints of leg (incl. knee and ankle) Flashcards
Patella - Knee cap
- largest sesamoid bone of the body
- suspended in the main extensor tendon of the knee
- The deep surface of the patella forms part of the knee joint. [deep surface is smooth, lined with hyaline cartilage, and articulates with patellar surface of distal femur.]
[superficial surface is rough, tendon inserts there]
tibia and fibula
tibia: articulates with: condyles of femur (posteriorly) and talus (inferiorly)
fibula: muscle attachment, and stability of ankle joint
connected by interosseous membrane
tibiofibular joint proximal and distal
Tibia ; articulation
- weight bearing (shin) bone
- second largest bone in body
- Articulation:
- knee joint
- proximal tibiofibular joint
- distal tibiofibular joint
- medial malleolus of ankle joint
Tibia - bony landmarks - proximal
- medial and lateral condyles
- medial and lateral tibial plateau - articular surface
- lateral condyles
- the anteriolateral tibial tubercle (gerdys tubercle) attachment of illiotibial and fascia of lateral thigh
- fibular articular facet on lateral condyle
- Intercondylar eminence
- medial and lateral intercondylar tubercles - fit into intercondylar fossa between femoral condyles
- intercondylar areas (anterior and posterior
- attachment sites for menisci and knee ligaments
Tibia - bony landmarks - anterior
- shaft of tibia: triangular cross-section
- surfaces: medial, lateral/interosseous, posterior
- Shin: anterior border of medial surface
- tibial tuberosity: distal attachment for patellar ligament
- interosseous border: attachment of interosseous membrane
- fibular notch: fibrous attachment at distal tibiofibular joint
Tibia - bony landmarks - posterior
- soleal (popliteal) line: diagonal ridge runs inferomedially to the medial border, for soleus tendon
- nutrient foramen: main artery supplying proximal end of bone and marrow
- medial malleoulus: extends inferior to shaft
- lateral surface of medial malleolus and inferior shaft articulate with talus
Fibula
- slender non-weight bearing bone
- the fibuLA is LAteral to the tibia
- site for muscle attachment
- 1 muscle insertion
- 8 muscle origin
- Articulation:
-Proximal tibiofibular joint
*Distal tibiofibular joint
*Forms lateral malleolus of the ankle
*Does NOT articulate with femur at knee joint
Fibula - bony landmarks - Proximal
-Enlarged head superior to small neck
-Common fibular nerve wraps around neck
-Head has pointed apexand articulates with fibular facet on lateral tibial condyle
Fibula - bony landmarks - distal
- Enlarged
- Lateral elongation to form lateral malleolus of ankle joint
Fibula - bony landmark - shaft
*Twisted and marked by sites of muscle attachment
*Triangular cross section
*Borders: anterior, interosseous, posterior
*Surfaces: medial, posterior, lateral
Palpable landmarks of tibia and fibula - surface anatomy
- Palpable landmarks
- Tibial tuberosity
- Anteromedial surface of the tibia
- Tibial condyles
- Head of fibula
- Neck of fibula (note common fibular nerve passing)
- Medial malleolus
- Lateral malleolus
Tibiofibular joints
Proximal tibiofibular joint
Distal tibiofibular joint
interosseous membrane
joins shafts of tibia and fibula
Oblique fibre direction of ligaments and membrane
- fibres extend inferolaterally from tibia toward fibula
- allow upward movement of fibula during dorsiflexion when wide end of trochlea of the talus is wedged between the malleoli
- resist downward pull due to 8 muscle origins
Proximal tibiofibular joint; articulation
Plane synovial joint
articulation: head of fibula and fibular articular facet on lateral condyle of tibia
Proximal tibiofibular joint; ligaments + movement
- anterior and posterior ligaments of the fibular head
Movement:
slight movement during dorsiflexion of foot due to wedging of trochlea of the talus between the malleoli
Proximal tibiofibular joint; blood supply + innervation
Blood supply: inferior lateral genicular and anterior tibial recurrent arteries
Innervation: common fibular nerve and nerve to the popliteus
distal tibiofibular syndesmosis; articulation
articulation: distal medial surface of fibula and fibular notch of tibia
distal tibiofibular syndesmosis; fibrous joint
Fibrous joint (syndesmosis):
*Interosseous tibiofibular ligament (continuation of interosseous membrane)
*Anterior tibiofibular ligament
*Posterior tibiofibular ligament (inferior transverse tibiofibular ligament)
distal tibiofibular syndesmosis; ankle joint stabiliser
-Keeps lateral malleolus firmly against lateral surface of the talus
*Inferior transverse ligament forms posterior wall of the malleolar mortise for the trochlea of the talus
distal tibiofibular syndesmosis; movement
movement: slight upward movement during dorsiflexion
distal tibiofibular joint (tibiofibular syndesmosis); blood supply + innervation
Blood supply: perforating branch of fibular artery, and medial malleolar branches of anterior and posterior tibial arteries.
Innervation: deep fibular, tibial and saphenous nerves
Knee joint; consists of?
- hinge type synovial joint
> flexion, extension
> also gliding, rolling, and rotation - 3 joints in a single cavity
> lateral tibiofemoral joint
> medial tibiofemoral joint
> intermediate patellofemoral joint - fibula is not involved
tibiofemoral joint
- medial and lateral condyles of femur articulate with medial and lateral condyles of tibia
- non-articular area between condyles
- weight bearing joint of the knee
patellofemoral joint
- facets of the patella articulate with the patellar groove on anterior surface of femur
- allows the pull of the tendon of quadriceps femoris (the main extensor) to be directed anteriorly over knee without tendon wear and increased leverage