Lower Limb Joints and Ligaments

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Lower Limb Joints and Ligaments

  • Hip (coxal) joint
    • Is a multiaxial ball-and-socket synovial joint
    • Is stabilized by the acetabular labrum; the fibrous capsule; and capsular ligaments such as the iliofemoral, ischiofemoral, and pubofemoral ligaments.
    • Has a cavity that is deepened by the fibrocartilaginousacetabular labrum
    • transverseacetabular ligament bridges and converts the acetabular notch into a foramen for passage of nutrient vessels and nerves.
    • Receives blood from branches of the medial and lateral femoral circumflex, superior and inferior gluteal, and obturator arteries.
    • The posterior branch of the obturator artery gives rise to the artery of the ligamentumterescapitisfemoris (MCQ)
  • Fibrous and Cartilaginous Structures
    • Fibrous Capsule
      • Encloses part of the head and most of the neck of the femur.
      • Is reinforced
        • anteriorly by the iliofemoralligament
        • posteriorly by the ischiofemoralligament
        • inferiorly by the pubofemoralligament.
  • Ligaments
    • Iliofemoral Ligament
      • Is the largest and most important ligament
      • reinforces the fibrous capsule anterIorlyand is in the form of an inverted Y.
      • Resists hyperextension and lateral rotation at the hip joint during standing
    • Ischiofemoral Ligament
      • It limits extension and medial rotation of the thigh.
    • Pubofemoral Ligament
      • It limits extension and abduction.
    • LigamentumTeresCapitisFemoris(Round Ligament of Head of Femur)
      • Arises from the floor of the acetabular
      • Provides a pathway for the artery of the ligamentumcapitisfemoris (foveolar artery) from the obturator artery
      • obturator arteryrepresents a significant portion of the blood supply to the femoral head during childhood.
    • Transverse Acetabular Ligament
  • Knee joint
    • Is the largest and most complicatedjoint.
    • structurally it resembles a hinge joint
      • it is a condylar type of synovial joint between two condyles of the femur and tibia.it includes a saddle jointbetween the femur and the patella.
    • fibrous capsule
      • thin, weak, and incomplete,
      • surrounds the lateral and posterior aspects of the joint.
    • full extension is accompanied by medial rotation of the femur on the tibia, pulling all ligaments taut.
    • Is stabilized laterally by the biceps and gastrocnemius (lateral head) tendons, the iliotibial tract, and the fibular collateral ligaments.
    •  Is stabilized medially by the sartorius, gracilis, gastrocnemius (medial head), semitendinosus, and semimembranosus muscles and the tibial collateral ligament.
    • Receives blood from the
      • genicular branches (superior medial and lateral, inferior medial and lateral, and middle) of the popliteal artery
      • descending branch of the lateral femoral circumflex artery
      • articular branch of the descending genicular artery
      • anteriortibial recurrent artery.
      • Ligaments
  • Intracapsular Ligaments
    • Anterior Cruciate Ligament
      • Lies inside the knee joint capsule but outside the synovial cavity of the joint.
      • Arises from the anterior intercondylar area of the tibia and passes upward, backward,and laterally to insert into the medial surface of the lateral femoral condyle.
      • Is slightly longer than the posterior cruciate ligament.
      • Prevents forward sliding of the tibia on the femur(or posterior displacement of thefemur on the tibia) and prevents hyperextension of the knee joint.
      •  Is taut during extension of the knee and is lax during flexion
      • The small, more anterior band is taut during flexion
      • May be torn when the knee is hyperextended.
    • Posterior Cruciate Ligament
      • Lies outside the synovial cavity but within the fibrous joint capsule.
      • Arises from the posterior intercondylar area of the tibia
      • passesupward, forward,and medially to insert into the lateral surface of the medial femoral condyle.
      • Is shorter, straighter, and strongerthan the anterior cruciate ligament.
      • Prevents backward sliding of the tibia on the femur
      • Prevents anterior displacement of thefemur on the tibia
      • limitshyperflexion of the knee.
      • Is taut during flexion of the knee and is lax during extension.
      • The small posterior bandis lax during flexionand taut during extension
    • Medial Meniscus
      •  Lies outside the synovial cavity but within the joint capsule.
      • Is C shaped (i.e., forms a semicircle)
      • is attached to the medial collateral ligamentand interarticular area of the tibia.
      • Acts as a cushion or shock absorber
      • It lubricates the articular surfaces by distributing synovial fluid in a windshield-wiper manner.
    • Lateral Meniscus
      • Lies outside the synovial cavity but within the joint capsule.
      • Is nearly circular
      • acts as a cushion, and facilitates lubrication.
      • Is separated laterally from the fibular (or lateral) collateral ligament by the tendon ofthe popliteal muscle and
      • aids in forming a more stable base for the articulation ofthe femoral condyle.
    • Transverse Ligament
      • Binds the anterior horns (ends) of the lateral and medialmenisci
      • Extracapsular Ligaments
    • Medial (Tibial) Collateral Ligament
      • Is a broad band that extends from the medial femoral epicondyle to the medial tibialcondyle.
      • Is firmly attached to the medial meniscus
      • injury to the ligament results in concomitant damage to the medial meniscus.
      • Prevents medial displacement of the two long bones and thus abduction of the leg at the knee.
      • Becomes taut on extension and thus limits extension and abduction of the leg.
    • Lateral (Fibular) Collateral Ligament
      • Is a rounded cord
      • It is separated from the lateral meniscus by the tendon of the popliteus muscle and also from the capsule of the joint.
      • Extends between the lateral femoral epicondyle and the head of the fibula.
      • Becomes taut on extensionand limits extension and adductionof the leg.
    • Patellar Ligament (Tendon)
      • Is a strong flattened fibrous band
      • it is the continuation of the quadriceps femoris tendon
      • Its portion may be used for repair of the anterior cruciate ligament.
      • Extends from the apex of the patella to the tuberosity of the tibia.
    • Arcuate Popliteal Ligament
      • Arises from the head of the fibula
    • Oblique Popliteal Ligament
      • Is an oblique expansion of the semimembranosus tendonand passes upward
      • obliquely across the posterior surface of the knee joint from the medial condyle ofthe tibia.
      • Resists hyperextension of the leg and lateral rotation during the final phase of extension.
    • PopliteusTendon
      • Arises as a strong cord-like tendon from the lateral aspect of the lateral femoral condyle
      • runs between the lateral meniscus and the capsule of the knee joint deep to the fibular collateral ligament.
      • Bursae
    • Suprapatellar Bursa
      • Lies deep to the quadriceps femoris muscle
      • the major bursa communicating with the knee joint cavity (the semimembranosus bursa also may communicate with it).
    • Prepatellar Bursa
      • Lies over the superficial surface of the patella
    • Infrapatellar Bursa
      • Consists of a
        • subcutaneousinfrapatellar bursa over the patellar ligament
        • deepinfrapatellar bursa deep to the patellar ligament.
    • Anserine Bursa (Known as the PesAnserinus [Goose’s Foot])
      • Lies between the tibial collateral ligament and the tendons of the sartorius, gracilis, and semitendinosus muscles.
  • Tibiofibular joints
    • Proximal Tibiofibular Joint
      • Is a plane-type synovial joint
      • Occur between the head of the fibula and the tibia
      • allows a little gliding movement.
    • Distal Tibiofibular Joint
      • Is a fibrous joint between the tibia and the fibula.
  • Ankle (talocrural) joint
    • Is a hinge-type (ginglymus) synovial joint
    • Occurs between the
      • tibia and fibula superiorly
      • trochlea of the talus inferiorly
    • permitdorsiflexion and plantar flexion.
  • Articular Capsule
  • Is reinforced
    • medially by the medial (or deltoid) ligament
    • laterally by the lateral ligament, which prevents anterior and posterior slipping of the tibia and fibula on the talus.
  • Ligaments
    • Medial (Deltoid) Ligament
      • Has four parts
        • Tibionavicular
        • tibiocalcaneal,
        • anteriortibiotalar
        • posteriortibi- otalar ligaments.
      • Extends from the medial malleolus to the navicular bone, calcaneus, and talus.
      • Prevents overeversion of the foot
      • helps maintain the medial longitudinal arch.
    • Lateral Ligament
      • Consists of the
        • anteriortalofibularligament.
        • posteriortalofibularligament.
        • calcaneofibular (cord- like) ligament.
      • Resists inversion of the foot
      • torn during an ankle sprain (inversion injury)(MCQ)
  • TARSAL JOINTS
  • Intertarsal Joints
    • Talocalcaneal (Subtalar) Joint
      • Is a plane synovial joint (part of the talocalcaneonavicular joint), and is formed between the talus and calcaneus bones.
      • Allows inversion and eversion of the foot
    • Talocalcaneonavicular Joint
      • Is a ball-and-socket joint (part of the transverse tarsal joint
      • formed between the head of the talus (ball) and the calcaneus and navicular bones (socket).
      • Is supported by thespring (plantar calcaneonavicular) ligament
    • Calcaneocuboid Joint
      • Is part of the transverse tarsal joint
      • resemblesa saddle joint between the calcaneus and the cuboid bones.
      • Is supported by the
        • short plantar (plantar calcaneocuboid)
        • long plantar ligaments
        • tendon of the peroneus longus muscle.
    • Transverse Tarsal (Midtarsal) Joint
      • Is a collective term for thetalonavicular part of the talocalcaneonavicular joint and thecalcaneocuboid joint
      • Is important in inversion and eversion of the foot.

 

    • Surgical Anatomy
      • Posterior dislocation of the hip
        • accounts for approximately 90% of hip dislocations
        • It results in
          • rupture of posterior acetabular labrum
          • rupture of ligamentumcapitisfemoris
          • injury of the sciatic nerve.
        • It results in the affected lower limb being shortened, flexed, adducted, and medially rotated.
      • Anterior dislocation of the hip joint
        • femoral head is displaced anteroinferior to the acetabulum or the pubic bone.
        • The affected limb is slightly flexed, abducted, and laterally rotated.
      • Medial (central or intrapelvic) dislocation of the hip joint
        • occurs through a medial tearing of the joint capsule
        • dislocated femoral head lies medial to the pubic bone.
        • accompanied by acetabular fracture and rupture of the bladder.
      • Coxavalga
        • angle made by the axis of the femoral neck tothe axis of the femoral shaft exceeds 135 degrees
        • femoral neck becomes straighter.
      • Coxavara
        • angle made by the axis of the femoral neck to the axis of the femoral shaftis less than 135 degrees
        • femoral neck becomes more horizontal.
      • Drawer sign
        • anterior drawer sign
          • forward sliding of the tibia on the femur
          • due to a rupture of the anterior cruciate ligament
        • posterior drawer sign
          • backward sliding of the tibia on the femur
          • caused by a rupture of the posterior cruciate ligament.
      • medial meniscus is more frequently torn in injuries than the lateral meniscus because of its strong attachment to the tibial collateral ligament.
      • Unhappy triad or O’Donoghue’s triad of the knee joint
        • occur when a football player’s cleated shoe is planted firmly in the turf
        • knee is struck from the lateral side
        • It is indicated by a knee that is markedly swollen, particularly in the suprapatellar region
        • results in tenderness on application of pressure along the extent of the tibial collateral ligament.
        • It is characterized by
          • rupture of the tibial collateral ligament, as a result of excessive abduction
          • tearing of the anterior cruciate ligament, as a result of forward displacement of the tibia
          • injury to the medial meniscus, as a result of the tibial collateral ligament attachment.
      • Knock-knee (genu valgum)
        • is a deformity in which the tibia is bent or twistedlaterally.
        • It may occur as a result of collapse of the lateral compartment of the knee and rupture of the medial collateral ligament.
      • Bowleg (genu varum)
        • is a deformity in which the tibia is bent medially.
        • It may occur as a result of collapse of the medial compartment of the knee and rupture of the lateral collateral ligament.
      • Patellar tendon reflex:
        • Both afferent and efferent limbs of the reflex arc are in the femoral nerve (L2–L4).
        • A portion of the patella ligament may be used for surgical repair of the anterior cruciate ligament of the knee joint
        • The tendon of the plantaris muscle may be used for tendon autografts to the long flexors of the fingers.
      • Prepatellar bursitis (housemaid’s knee)
        • inflammation and swelling of theprepatellar bursa.
      • Infrapatellar (superficial) bursitis (clergyman’s knee)
        • inflammation of the infrapatellar bursa
      • Popliteal (Baker’s) cyst
        • swelling behind the knee
        • caused by knee arthritis, meniscus injury, or herniation or tear of the joint capsule
        • It impairs flexion and extension of the knee joint
        • pain gets worse when the knee is fully extended, such as during prolonged standing or walking. I
        • it can be treated by draining and decompressing the cyst.
      • Bunion
        • localized swelling at the medial side of the first metatarsophalangeal joint (or of the first metatarsal head)
        • caused by an inflammatory bursa
        • unusually associated with hallux valgus
      • Hallux valgus
          • lateral deviation of the big toe
          • frequently accompanied by swelling (bunion) on the medial aspect of the first metatarsophalangeal joint.


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