Popliteal Fossa And Leg Flashcards
What is crural fascia?
- The deep fascia of the thigh
- continuous with the fascia lata
- continuous with the periosteum of the tibia on its anterior and medial surfaces
Where is crural fascia thickened?
- near the distal end of the leg
- thickened as superior and inferior extensor retinacula
Anterior and posterior crural intermuscular septa
- extend from the deep side of the fascia
- attach to the lateral edge of the fibula and divide the 3 compartments of the leg
Tibial nerve
- formed from ventral divisions of ventral rami L4-S3
- branch of sciatic nerve
What do the muscular branches of the tibial nerve innervate?
The muscles of the posterior compartment of the leg
-this ends as the medial and lateral plantar nerves of the foot
Medial sural cutaneous nerve
- contributes to sural nerve
- cutaneous nerve that innervates the inferior lateral posterior part of leg and sole of foot
Common fibular nerve
- branches into superficial and deep branches (innervate the 2 muscular compartments of leg)
- wraps laterally around the neck of the fibula and then deep to the peroneus longus muscle
Deep fibular nerve
- innervates the muscles of the anterior crural compartment
- pierces the anterior crural intermuscular septum to descend on the anterior surface of the interosseus membrane
- deep to the extensor retinacula
Superficial fibular n.
- innervates the muscles of the lateral crural compartment
- descends posterolateral to the anterior crural intermuscular septum
What makes up the genicular anastomosis?
- medial and lateral superior genicular arteries
- middle genicular artery
- medial and lateral inferior circumflex femoral artery
- descending branch of the lateral circumflex femoral artery
- anterior and posterior recurrent tibial artery
- circumflex fibular artery
Popliteal artery has muscular branches to?
The heads of the gastrocnemius
What are the terminal ranches of the popliteal artery?
-anterior and posterior tibial arteries
Anterior tibial artery branch
-penetrates the interosseus membrane to reach the anterior compartment of the leg
Anterior tibial artery
- becomes dorsalis pedis artery on the dorsal surface of the foot
- supplies the anterior muscle compartment
Posterior tibial artery
- neurovascular bundle (post. tibial artery + nerve) lies between the superficial and deep divisions of the posterior compartment of the leg
- goes around medial malleolus to end on plantar surface of foot as medial and lateral plantar artery
Fibular artery
-begins distal to popliteus muscle and descends along fibula
Muscular branches of fibular artery supply blood to?
- the lateral crural compartment
- since there is no major artery in the lateral compartment
Shin splints
- inflammation or swelling of tibialis anterior
- causing pressure on encasing crural fascia
- tearing of tibialis anterior origin
- tibialis posterior attached to interosseus membrane is irritated with excess/forceful dorsiflexion
Foot drop
-loss of tibialis anterior by damage to sciatic, common peroneal, or deep peroneal
Main dorsiflexor
Tibialis anterior
Most common sites for sciatic damage
Severe trauma in the gluteal region or posterior thigh
How can the common fibular nerve be damaged?
Due to blunt trauma
-it is close to the surface
What type of joint is the knee joint?
Hinge type synovial
-permitting some rotation
Describe the femur when knee is fully extended and ‘locked’
Femur is medially rotated on the tibia (closed chain)
What is the role of the popliteus muscle?
It laterally rotates the femur and “unlocks” the knee extension
Popliteus action in open chain
Medially rotate the tibia on the femur
Lateral collateral ligament
- splits the tendons of insertion of the two heads of biceps
- overlies the origin of the popliteus
Medial collateral ligament
-medial fibers are strongly attached to the medial meniscus (intrinsic)
Patellar ligament
- external
- intrinsic part close to patella as it approaches the articular surface
Oblique popliteal ligament
- tendon of semimembranosus
- intrinsic-support of capsule
Arcuate popliteal ligament
- branched ligament from head of fibula to the intercondylar space of tibia and lateral epicondyle of femur
- intrinsic-support of capsule
Internal ligaments of the knee:
- anterior cruciate
- posterior cruciate
- medial meniscus
- lateral meniscus
Anterior cruciate ligament
- Prevents posterior displacement of femur on tibia
- tight when fully extended
Posterior cruciate ligament
- prevents anterior displacement of femur on tibia
- tight when fully flexed
Medial meniscus
Attached to tibia by coronary ligament
Lateral meniscus
Attached to tibia by coronary ligament
Proximal tibiofibular joint
- Synovial joint planar type
- supported by fibrous capsule surrounding joint
Distal tibiofibular joint
- fibrous syndesmosis type
- anchored by an interosseous membrane
Transverse tibiofibular ligament
-deep part of the posterior tibiofibular ligament
