Lecture 15: Joints Of Lower Extremity Flashcards
What 4 structures act as joint stabilizers in the knee?
Capsule
Ligaments
Muscle tendons and tone
Menisci
What ligament is taut in knee flexion?
Posterior cruciate ligament
What ligmanet is taut in knee extension?
Anterior cruciate ligament
[prevents anterior displacement of tibia and prevents posterior displacement of femur]
The ACL is attached to the anterior part of the intercondylar area of the ______, and the medial side of the lateral condyle of the ______
Fibers are oriented superiorly, posteriorly, and laterally
Tibia; femur
The PCL is attached to the posterior part of the intercondylar area of the ____, and lateral surface of medial condyle of _______
Fibers are directed superiorly, anteriorly, and medially
Tibia; femur
The PCL is taut when the leg is flexed, which prevents anterior displacement of the ______, and posterior displacement of the _____
Femur; tibia
The anterior drawer sign tests what ligament of the knee
ACL
What ligament is tested with posterior drawer sign?
PCL - posterior cruciate ligament
The menisci of the knee are semilunar wedge shaped fibrocartilages within the knee joint attached to the joint capsule. They are bathed in synovial fluid and connected to the joint capsule.
What are the 2 main functions of the menisci?
Deepen the articular surface
Shock absorption
The medial and lateral menisci of the knee are joined anteriorly by what ligament?
Transverse ligament
A medial meniscal tear would cause pain with what type of motion?
Medial rotation
The medial meniscus is broader posteriorly. Its anterior horn is attached to tibia anterior to the _______, and the posterior horn is attached to tibia anterior to the _______
It is adherent to the deep surface of the ______ ______ ligament
ACL; PCL
Tibial collateral
Which meniscus is nearly circular, smaller, and more mobile than the other?
Lateral meniscus
What joins the lateral meniscus to the posterior cruciate ligament?
The posterior meniscofemoral ligament
What tendon passes between the lateral meniscus and the fibular collateral ligament?
Popliteus tendon
Which meniscus is more likely to tear and why?
Medial meniscus because the lateral is more mobile
What type of meniscal tear is able to heal on its own and why?
Peripheral meniscal tears, because there is blood supply there
[meniscal tears that do not heal or cannot be repaired are removed via arthroscopic surgery]
What elements of the knee are damaged in an “unhappy triad” knee injury?
Tibial collateral ligament
Medial meniscus
Anterior cruciate ligament
What type of force leads to an unhappy triad injury?
Excessive lateral force when foot is planted and knee is twisted
The anatomical term for the ankle joint
Tibiotalar joint
The tibiotalar joint is made up of the inferior ends of the tibia and fibula and the talus (trochlea). The 3-sided mortise (deep socket) is formed by 2 malleoli and the inferior tibia.
The malleoli grip on the trochlea the strongest during which type of motion at the ankle?
Dorsiflexion
[the wider, anterior part moves posteriorly, spreading the leg bones]
What type of joint is the ankle (tibiotalar) joint and what type of motion does it do?
Hinge synovial joint: dorsiflexion and plantarflexion
Describe the articular capsule of the tibiotalar joint
Thin anteriorly and posteriorly
Each side is supported by strong collateral ligaments: medial and lateral
What ligament stabilizes the ankle during eversion?
Medial (deltoid) ligament
What are the 4 parts of the medial (Deltoid) ligament, named from leg bone to foot bone?
Anterior tibiotalar part
Tibionavicular part
Tibiocalcaneal part
Posterior tibiotalar part
The lateral ligaments of the tibiotalar joint consist of how many discrete ligaments that attached the lateral malleolus to talus and to the calcaneus?
Three
What are the 3 discrete lateral ligaments of the tibiotalar joint, named from foot bone to leg bone?
Posterior talofibular ligament
Anterior talofibular ligament
Calcaneofibular ligament
What joint exists where the talus rests on the calcaneus?
Subtalar (talocalcanean) joint
What are the main movements of the subtalar joint?
Inversion and eversion
The subtalar joint consists of a fibrous capsule supported by talocalcaneal ligaments. How is weight transferred in the subtalar (talocalcaneal) joint?
Weight is transferred from tibia to talus, then to the calcaneus
What is the most frequently injured joint in the body?
Ankle
What type of injury is an ankle sprain?
Ligament fiber tears, almost always an inversion injury
What is the most commonly injured ligament in the ankle?
Anterior talofibular ligament
[calcanofibular ligament also may be torn]
What type of fracture is characterized by a fragment of bone being torn off by an attached ligament?
Avulsion fracture
The transverse tarsal joint is formed by what 2 separate joints aligned transversely?
Talonavicular joint
Calcaneocuboid joint
What motions are performed at the transverse tarsal joint?
Together they permit slight rotation and thus add to inversion and eversion at the talocalcaneal joint
Transection across which joint is the standard method for surgical amputation of the foot?
Transverse tarsal joint
Which part of the foot is the primarily weight bearing part?
Medial longitudinal arch (calcaneus, talus, navicular, 3 cuneiforms, and medial 3 metatarsals)
If the medial longitudinal arch is the primarily weight bearing part of the foot, what is the primary purpose of the lateral arch of the foot?
Balance
What bones form the lateral foot arch?
Calcaneus, cuboid, lateral 2 metatarsals
What bones form the transverse arch of the foot?
The transverse arch runs between the medial and lateral longitudinal arches; formed by cuboid, 3 cuneiforms, and metatarsal bones
What are the dynamic longitudinal stabilizers of the arch of the foot?
Tibialis anterior and posterior
Flexor hallucis longus
Intrinsic plantar muscles
What are the passive longitudinal stabilizers of the arches of the foot?
Plantar aponeurosis, short and long plantar ligaments, and the plantar calcaneonavicular ligament (spring ligament)
A passive fallen arch is primarily due to a laxity in what ligament of the foot?
Spring ligament (plantar calcaneonavicular ligament)
The arch of the forefoot only has ______ stabilizers, whereas the arches of the metatarsus and tarsus have only ______ stabilizers
Passive; active/dynamic
What is the clinical term for flat feet?
Pes planus
In adolescents and adults, what causes pes planus?
“Fallen arches”, usually in medial parts of the longitudinal arch
Plantar ligaments and plantar aponeurosis become abnormally stretched
Plantar calcaneonavicular ligament can no longer support the talus head - talar head displaces inferomedially and becomes prominent
