Posterior Compartment Of Thigh, Popliteal Fossa, Knee Joint, Osteology Of Leg And Foot Flashcards
Muscles of Posterior Compartment of the Thigh
Principles
The “Hamstrings”
From ischial tuberosity to tibial condyles; head of fibula
Extend the thigh and flex the leg
Semitendinosus
Posterior Thigh
Prox: ischial tuberosity
Distal: medial part of the proximal tibia
Innervation: Tibial division of the sciatic nerve
Actions: extend thigh; flex and medially rotate the leg
Semimembranosus
Posterior Thigh
Prox: ischial tuberosity
Distal: medial condyle of the tibia
Innervation: Tibial division of the sciatic nerve
Action: extend thigh; flex and medially rotate the leg
Biceps femoris
Posterior Thigh
Prox: long head-ischial tuberosity
Short head-linea aspera
Distal: Head of fibula
Innervation: Long head-tibial division of sciatic nerve
Short head-common Fibular division of the sciatic nerve
Action: extend the thigh; flex and laterally rotates the leg
Sciatic Nerve (L4, 5, S1, 2, 3)
Nerve supply to the posterior compartment of the thigh
Posterior Femoral Cutaneous Nerve
S1, 2, 3
Innervates the skin of the posterior thigh (medial to sciatic nerve)
passes deep to the fascia lata
Innervates skin over the popliteal fossa too
Blood Supply to the Muscles of the Posterior Thigh
Superior Gluteal Artery (Gluteus Maximus/Medius/Minimus)
Inferior Gluteal Artery (Gluteus Maximus)
Internal Pudendal Artery ?
Perforating Arteries (of the profunda femoral artery) enter the posterior compartment and provide muscular branches to the hamstrings (travel within adductor magnus and brevis)
Bursa and Clinical Significance
Bursa: synovial fluid filled sac that helps to reduce the friction btwn bone and a muscle or a bone and a tendon
Clinical Significance: Infection or irritation of a bursa can lead to and inflammation of the bursa “bursitis”
Pew Anserinus (anatomic name of 3 conjoined tendons on medial aspect of the knee)
From anterior to Posterior: sartorius, gracilis and semitendinosus
Clinic: bursa lies btwn pets anserinus tendons and the more deeply located semimembranosus tendon; bursa can become inflamed and symptomatic (pes anserinus bursitis)
Pneumonic: SGT FOT
Adductor Magnus
Prox: adductor part-ischiopubis ramus [pubofemoral portion]
Hamstring part-ischial tuberosity [ischiocondylar portion]
Distal: adductor part-shaft of femur
Hamstring part-adductor tubercle of femur
Innervation: A-obturator nerve
H-tibial division of sciatic nerve
Actions: A: adducts/flexes thigh
H: adducts/extends thigh
Articulations between femur and tibia
condyles of femur (with tibial plateus)
Condyles of tibia and cartilaginous menisci
Femur and patella
Capsule of the Knee Joint
Extends from femur to tibia Strengthened by fibers from the: -fascia lata -Iliotibial tract -tendons of the vasti, hamstrings and Sartorius muscles
Patellar ligament
From the apex of the patella to the tuberosity of the tibia; helps hold patella in place and serves as part of the “tendon” of the quadriceps Femoris muscle (patellar ligament is still distinct)
Oblique popliteal ligament
From the lateral femur to the posterior tibia; reinforces posterior surface of the joint capsule
Continuation of the insertion of the semimembranosus muscle
Arcuate popliteal ligament
From the lateral condyle of the femur to the head of the fibula; arches over the tendon of the popliteus muscle; stabilizes the posterior aspect of the knee joint
Anterior Cruciate Ligament
From the front of the intercondylar eminence to the medial surface of the lateral femoral condyle posteriorly; Checks extension and anterior slipping of the tibia on the femur (or posterior displacement the femur on the tibia)
Posterior Cruciate Ligament
From the posterior intercondylar fossa and to the lateral surface of the medial femoral condyle anteriorly; checks flexion and posterior slipping of tibia on the femur (or anterior displacement of the femur on the tibia)
ACL tears
Occur when a severe force is directed anteriorly with the knee semiflexed. This is one of the most common knee injuries a resulting from skiing accidents. The ACL may tear way from the femur or tibia; tears more commonly occur in the mid portion of the ligament. The torn ACL will permit the tibia to slide anteriorly on the femur (anterior Drawer sign)
PCL tears
PCL is strong, a rupture may occur when an individual lands on their tibial tuberosity with knee flexed (e.g. Knocked to the floor in basketball)
A tear frequently occurs in head-on collisions when seat belts aren’t worn and the proximal end of the tibia strikes the dashboard
Torn PCL will permit tibia to slide posteriorly on the femur-the posterior drawer sign
Medial Meniscus
Crescent-shaped; attach to tibia anterior to the anterior cruciate ligament and to the posterior intercondylar area; deepens the medial tibial condyle; the medial (tibial) collateral ligament is firmly attached to the medial meniscus
Lateral Meniscus
Nearly circular; attached to the tibia anterior to the ACL; posteriorly attached behind behind the intercondylar eminence anterior to the medial meniscus
(No lateral attachment to the LCL)
Medial collateral ligament
A broad flat band located slightly posterior on the medial side of the knee joint. It’s attached proximal to the medial epicondyle of the femur right below the adductor tubercle. The distal attachment is to the medial condyle of the tibia. It resists forces that would push the knee joint medially. The MCL is fused to the medial meniscus
Lateral Collateral Ligament
Rounded, more narrow and less broad than the MCL, the LCL stretches downward from the lateral epicondyle of the femur above, to the head of the fibula below. In contrast to the MCL, it isn’t fused with the lateral meniscus. Because of this, the LCL is less susceptible to injury
Clinic: forces that damage the MCL
A force pushing on the knee joint from the lateral or outer surface causing stress on the medial side
LCL tear
Can result from a force pushing the knee from the medial/inner side of the joint causing stress on the outside
Clinic: Firm attachment of the MCL to the medial meniscus is of considerable clinical significance
Tearing of the MCL frequently results in concomitant tearing of the medial meniscus. This commonly occurs from a blow to the lateral side of the knee with twisting when the knee is flexed. The ACL may also tear resulting in an “UNHAPPY TRIAD”
Bursae of the Knee Joint
Closed fibrous sac lined with synovial membrane producing synovial fluid; found in regions where musclesa and tendons rub against other muscles, tendons or bones; function by lubricating points of friction and dissipating force by distributing it thru a fluid medium
Bursitis of the Knee
Constant irritation of a bursa may lead to over secretion and enlargement of the bursa, a condition known as bursitis `
Knee Deformities
Genu Varum and Genu Valgrum
Varum: medial deviation of the tibia
Valgrum: lateral deviation of the tibia
These deformities cause unequal weight distribution (e.g. In the varum deformity, the medial side of the knee takes all the pressure, leading to wear and tear of medial meniscus)
Genu Recurvatum
Knee is hyperextended such that the lower extremity curves. The convexity of the curve is Posterior and can be symmetrical or unilateral
Popliteal Fossa
Diamond shaped depression posterior to the knee joint
Bounded by:
-Superolaterally: the biceps femoris muscle
-superomedially: semimembranosus and semitendinosus muscles
-inferolaterally and inferomedially: the lateral and medial heads of the gastrocnemius muscle
-Posteriorly: skin and the popliteal fascia form the roof
Femoral Artery and Vein (saphenous nerve) path thru adductor canal
They pass down in adductor canals (anterior thigh) and emerge from the adductor hiatus as the popliteal Artery and vein `
BUT the saphenous nerve passes under the septum (doesn’t leave through adductor hiatus)
Contents of the popliteal fossa
- termination of the small saphenous vein
- popliteal artery and vein (continuation of the femoral vessels after they pass thru the adductor hiatus)
- tibial (supplies posterior and anterior compartments) and common fibular nerves (moves down and wraps around head of fibula)
- posterior cutaneous nerve of the thigh
- popliteal lymph nodes and lymphatic vessels
Popliteus
Prox: lateral epicondyle of femur
Distal: posterior surface of proximal tibia
innervation: tibial nerve
Action: weakly flexes the knee; unlocks extended knww
Plantaris
Prox: lateral side of distal femur
Distal: calcaneous tendon
Inner aviation: tibial nerve
Action: Weak plantar flexion
Interosseous Membrane
Osteology of tibia and fibula
a strong, fibrous sheet that connects the interosseous margin of the tibia and the interosseous margin of the fibula, filling the gap btwn the 2 bones except at the proximal and distal ends where there exist openings in the membrane that allow for passage of vessels
Stabilizes the tibiofibular junction and provide attachment for many of the leg muscles
Bones of foot
Calcaneus Talus Cuboid Navicular Cuneiform bones (lateral, intermediate, medial)
Joints of the ankle
Ankle joint (talocrural) Subtalar joint
Talocrural (ankle) Joint
Dorsiflexion and plantarflexion
Hinge joint
Subtalar joint (talocalcaneal joint)
Inversion and eversion of the foot
Lateral Collateral ligament (complex) of the ankle
Set of 3 ligaments that resist inversion of the ankle joint
More Commonly injured than the medial collateral ligament of the ankle
Run from the lateral malleolus to the talus and calcaneus
Posterior talofibular ligament
Anterior talofibular ligament
Calcaneofibular ligament
Deltoid (Medial) Ligament
attach the medial malleolus to multiple tarsal bones
Stabilizes the medial side of the ankle joint
Prevents excessive eversion of the ankle joints
Anterior parts of the ligament limit plantar flexion and posterior parts of the ligament limit dorsiflexion
Ankle Sprain
Most common type: foot in plantar flexion, inverted and abducted
Strain is focused on the calcaneofibular and anterior talofibular ligaments of the LATERAL LIGAMENT OF THE ANKLE JOINT
Pott’s Fracture-dislocation of the ankle
Occurs when the foot is forcibly exerted. This action pulls the extremely strong medial ligament
Often the medial malleolus is pulled off the tibia-if this happens, the talus moves laterally, shearing off the lateral malleolus or breaking the fibula superior to the inferior tibiofibular joint
