Joints of the Lower Limb - Hip, Knee, and Ankle Flashcards

A comprehensive set of Q&A style flashcards covering the hip, knee, and ankle joints from the lecture notes, including joint type, articulating bones, capsules, ligaments, relations, blood and nerve supply, stability, movements, and clinical considerations.

What type of joint is the hip joint and which bones articulate there?

A multiaxial synovial ball-and-socket joint formed by the head of the femur and the acetabulum.

Describe the hip joint capsule.

Strong, dense capsule with attachments around the acetabulum and neck of the femur; contains circular and longitudinal fibres.

What lines the hip joint capsule and what is special about its reflection?

The synovial membrane lines the fibrous capsule and all intra-capsular surfaces except the articulating surfaces; reflection forms retinacula; subsynovial retinacular arteries.

Name the main ligaments of the hip joint and their relative strength.

Iliofemoral (inverted Y, strongest), Pubofemoral, Ischiofemoral (weakest); Ligament of the head of the femur (ligamentum teres) also present.

What are the anterior relations of the hip joint?

Pectineus, psoas major, iliacus muscles; aorta; inferior vena cava; femoral vessels; inguinal ligament; femoral nerve; femoral sheath; lymphatics in femoral canal.

What are the posterior relations of the hip joint?

Piriformis, obturator internus, gemelli; sciatic nerve; inferior gluteal vessels; superior gluteal vessels; perforating arteries and circumflex arteries.

What provides the arterial blood supply to the hip joint?

Retinacular arteries (branches of the medial and lateral circumflex femoral arteries); artery to the head of the femur from the obturator artery (ligament of the head) which obliterates around age 7.

List factors contributing to hip joint stability.

Fit between acetabulum and head; acetabular labrum; fibrous capsule and ligaments; short gluteal muscles.

What movements are possible at the hip joint?

Flexion, extension, abduction, adduction, lateral rotation, medial rotation, and circumduction.

Which nerves supply the hip joint?

Femoral nerve, obturator nerve, nerve to quadratus femoris, superior gluteal nerve.

What is a common clinical consequence of neck of femur fracture?

Disruption of blood supply to the femoral head leading to avascular necrosis; may require hip replacement; risk of dislocation.

What are the articular surface features of the hip?

Head of femur ~2/3 of a sphere; lunate surface of the acetabulum; acetabular labrum; transverse acetabular ligament.

What is the knee joint and how many articulations does it have?

The largest synovial joint; modified hinge; three articulations: medial femorotibial, lateral femorotibial, and femoropatellar.

Which bones form the knee joint articulations?

Distal femur (condyles) with proximal tibia (tibial condyles); patella; intercondylar region; menisci.

What is the function of the patella?

Sesamoid bone within the quadriceps tendon; articulates with the patellar surface of the femur; protects the tendon as it moves over the knee.

Describe the knee joint capsule.

Typical capsule with fibrous and synovial membranes; attachments around femoral and tibial margins; superior and inferior attachments; capsule reinforced by patella and quadriceps tendon; synovial membrane lines the capsule.

List the capsular ligaments of the knee.

Patellar ligament; fibular (lateral) collateral ligament; tibial (medial) collateral ligament; oblique popliteal ligament; arcuate popliteal ligament; patellar retinacula.

What is the function of the knee's capsular ligaments and patellar retinacula?

Strengthen the fibrous capsule; patellar ligament reinforces the anterior aspect; patellar retinacula are expansions of vastus medialis and lateralis.

What are the extracapsular ligaments of the knee?

Fibular (lateral) collateral ligament; extends from the lateral femoral epicondyle to the head of the fibula; separated from the lateral meniscus by the tendon of the oblique popliteus; cord-like and not part of the capsule.

What intra-articular structures are within the knee?

Medial and lateral menisci; popliteal tendon; cruciate ligaments (anterior and posterior); form an X-shaped arrangement; located in the joint cavity.

Describe the anterior cruciate ligament (ACL).

Weaker with poor blood supply; from the anterior intercondylar area of the tibia to the medial surface of the lateral femoral condyle; resists anterior displacement of the tibia and hyperextension; anterior drawer sign indicates damage.

Describe the posterior cruciate ligament (PCL).

From the posterior intercondylar area of the tibia to the lateral surface of the medial femoral condyle; resists posterior tibial movement and anterior movement of the femur; important for downhill stability.

What are the menisci and their functions?

Fibrocartilage crescent plates (lateral and medial); cushion, distribute synovial fluid, deepen articulation to improve congruency.

How do the lateral and medial menisci differ?

Lateral meniscus is ~4/5 of a circle, more mobile; medial meniscus is C-shaped, larger, thinner, less mobile, attached to the medial collateral ligament.

What supplies blood to the knee joint?

Capsular vessels and around-joint structures; main contributors are the five genicular branches of the popliteal artery; middle genicular artery supplies cruciate ligaments.

What nerves supply the knee joint?

Femoral nerve (to vasti), sciatic nerve (via genicular branches of tibial and common peroneal), obturator nerve.

What are the knee joint movements and their planes?

Flexion and extension in the sagittal plane; medial rotation (~0–10 degrees) and lateral rotation (~30 degrees) when the knee is flexed.

Who are the prime movers for knee extension and their nerve supply?

Quadriceps group (rectus femoris, vastus medialis, vastus lateralis, vastus intermedius) innervated by the femoral nerve (L2–L4).

What is the mechanism of knee locking?

Medial rotation of the femur on the tibia during the final stage of extension increases contact and tightens ligaments.

What is the mechanism of knee unlocking?

Lateral rotation of the femur on the tibia produced by the popliteus muscle to loosen ligaments.

What is knee joint stability dependent on?

Muscles, ligaments, and menisci; intercondylar eminence of the tibia provides some bony stability; bones contribute less.

Knee injuries: ACL and tests?

ACL tears often occur with abrupt stops; positive anterior drawer test indicates ACL damage.

Knee injuries: PCL and other ligaments?

PCL less commonly damaged; testing involves opposite movements; MCL injuries from valgus stress; LCL resists varus stress.

Which knee meniscus is more prone to tear and why?

Medial meniscus more prone due to less mobility and its attachment to the MCL.

Describe the ankle joint (talocrural) type and bones forming it.

Synovial hinge joint formed by the tibia, fibula, and talus (trochlea); mortise formed with the inferior transverse part of the posterior tibiofibular ligament.

Describe the ankle joint capsule.

Thin anteriorly and posteriorly; fibrous capsule attached to the articular margins of the three bones; synovial membrane lines margins.

Lateral ligaments of the ankle and their attachments?

Anterior talofibular, posterior talofibular, and calcaneofibular ligaments connecting fibula to talus and calcaneus.

Medial (deltoid) ligaments of the ankle and their parts?

Tibiocalcaneal, tibionavicular, anterior tibiotalar, and posterior tibiotalar parts.

Ankle joint blood supply and nerves?

Capsule and ligaments receive blood from the anterior and posterior tibial arteries and the peroneal (fibular) artery; nerves are deep peroneal and tibial.

Ankle joint movements?

Plantarflexion (gastrocnemius, soleus, long toe flexors) and dorsiflexion (tibialis anterior, long toe extensors, peroneus tertius).

What are the tarsal joints and their movements?

Talocalcaneal, calcaneocuboid, and talonavicular joints; movements include inversion and eversion; spring ligament supports the arch.

What is the function of the spring ligament in the foot?

Supports the medial longitudinal arch and stabilizes the talonavicular joint.

Guiding question: What bones form the hip, knee, and ankle joints, and what is the general nature of their articulations?

Hip: head of femur with acetabulum (ball-and-socket, very stable). Knee: three articulations (two femorotibial, one patellofemoral) with menisci and ligaments. Ankle: talocrural hinge formed by tibia, fibula, and talus; mortise with posterior tibiofibular ligament.