Lower Limb Bones and Joints | Anatomy2Medicine
joints of lower limb

Lower Limb Bones and Joints

 

  • Hip (coxal) bone

 

    • Is formed by the fusion of the ilium, pubis, and ischium in the acetabulum.
    • Articulates with the sacrum at the sacroiliac joint to form the pelvic girdle.
    • Ilium
    • Pubis
      • obturator foramen is formed by fusion of the ischium and pubis
    • Ischium

 

  • Has the ischial spine, ischial tuberosity, and lesser sciatic notch.

 

    • Acetabulum
      • Is an incomplete cup-shaped cavity on the lateral side of the hip bone
      • head of the femur fits into it

 

  • Includes the acetabular notch, which is bridged by the transverse acetabular ligament.

 

      • Is formed by the ilium superiorly, the ischium posteroinferiorly, and the pubis anteromedially.

 

  • Femur

 

    • Is the longest and strongest bone of the body.

 

  • Head

 

      • Forms about two-thirds of a sphere
      • directed medially, upward, and slightly forward to fit into the acetabulum.
      • Has a depression in its articular surface, the fovea capitis femoris, to which the ligamentum capitis femoris is attached.

 

  • Neck

 

      • forms an angle of about 125 degrees with the shaft
      • Is separated from the shaft in front by the intertrochanteric line, to which the iliofemoral ligament is attached.

 

  • Greater Trochanter
  • Provides an insertion for the gluteus medius and minimus, piriformis, and obturator internus muscles.

 

      • Receives the obturator externus tendon on the medial aspect of the trochanteric fossa.

 

  • Lesser Trochanter

 

      • Provides an insertion for the iliopsoas tendon.

 

  • Linea Aspera

 

      • Is the rough line or ridge on the body (shaft) of the femur.
      • Exhibits lateral and medial lips that provide attachments for many muscles and the three intermuscular septa.

 

  • Pectineal Line

 

      • Provides an insertion for the pectineus muscle.

 

  • Adductor Tubercle

 

      • Is a small prominence at the uppermost part of the medial femoral condyle.
      • Provides an insertion for the adductor magnus muscle.
    • Patella
    • Is the largest sesamoid bone
    • located within the tendon of the quadriceps femoris,
    • articulates with the femur but not with the tibia.
    • Attaches to the tibial tuberosity by a continuation of the quadriceps tendon called the patellar ligament.
    • Functions
      • obviate wear and attrition on the quadriceps tendon as it passes across the trochlear groove
      • increase the angle of pull of the quadriceps femoris, thereby magnifying its power
    • Tibia
    • Is the weight-bearing medial bone of the leg.

 

  • Has the tibial tuberosity into which the patellar ligament inserts.

 

  • Has medial and lateral condyles that articulate with the condyles of the femur.
  • Grooves
    • medial malleolus with a malleolar groove for the tendons of the tibialis posterior and flexor digitorum longus muscles
    • groove posterolateral to the malleolus groove for the tendon of the flexor hallucis longus muscle
    • It also provides attachment for the deltoid ligament

Fibula

    • Has little or no function in weight bearing
    • provides attachment for muscles.
    • Has a head (apex) that provides attachment for the fibular collateral ligament of the knee joint.
    • Has a projection called the lateral malleolus

 

  • articulates with the trochlea of the talus

 

    • lies more inferior and posterior than the medial malleolus
    • provides attachment for the anterior talofibular, posterior talofibular, and calcaneofibular ligaments
    • It also has the sulcus for the peroneus longus and brevis muscle tendons.

Tarsus

 

  • Consists of seven tarsal bones: talus, calcaneus, navicular bone, cuboid bone, and three cuneiform bones.

 

    • Talus
      • Transmits the weight of the body from the tibia to the foot
      • only tarsal bone without muscle attachments (MCQ)

 

  • Has a neck with a deep groove, the sulcus tali, for the interosseous ligaments between the talus and the calcaneus.
  • Has a body with a groove on its posterior surface for the flexor hallucis longus tendon.

 

      • Has a head, which serves as keystone of the medial longitudinal arch of the foot.
    • Calcaneus
      • Is the largest and strongest bone of the foot and lies below the talus.
      • Forms the heel of the foot,
      • articulates with the talus superiorly and the cuboid anteriorly
      • provides an attachment for the Achilles tendon.

 

  • Has a shelf-like medial projection called the sustentaculum tali, which supports the head of the talus (with the spring ligament
  • has a groove on its inferior surface for the flexor hallucis longus tendon (which uses the sustentaculum tali as a pulley).

 

    • Navicular Bone
      • Is a boat-shaped tarsal bone
      • lying between the head of the talus and the three cuneiform bones.
    • Cuboid Bone
      • Is the most laterally placed tarsal bone
      • has a groove for the peroneus longus muscle tendon.
      • Serves as the keystone of the lateral longitudinal arch of the foot
    • Cuneiform Bones
      • Are three wedge-shaped bones

 

  • form a part of the medial longitudinal and prox- imal transverse arches.

 

      • Articulate with the navicular bone posteriorly and with three metatarsals anteriorly.
    • Metatarsus
      • Consists of five metatarsals
      • has prominent medial and lateral sesamoid bones on the first metatarsal.

 

  • Surgical Anatomy of Bones

 

      • Fracture of the femoral head
        • caused by posterior hip dislocation
        • caused by osteoporosis
        • requires hip replacement.

 

  • It presents as a shortened lower limb with medial rotation.
  • Fracture of the neck of the femur

 

        • results in ischemic necrosis of the neck and head because of an interruption of blood supply from the root of the femoral neck to the femoral head by the medial femoral circumflex artery, except for its small proximal part.
        • It causes a pull of the distal fragment upward by the quadriceps femoris, adductors, and hamstring muscles
        • the affected lower limb is shortened with lateral rotation.
      • Pertrochanteric fracture
        • is a femoral fracture through the trochanters
        • is a form of the extracapsular hip fracture
        • The pull of the quadriceps femoris, adductors, and hamstring muscles may produce shortening and lateral rotation of the leg
        • It is common in elderly women because of an increased incidence of osteoporosis.
      • Fracture of the middle third of the femoral shaft
        • proximal fragment is pulled by the quadriceps and the hamstrings results in shortening
        • distal fragment is rotated backward by the two heads of the gastrocnemius.
        • A dislocated knee or fractured distal femur  injure the popliteal artery

 

  • Transverse patellar fracture

 

        • results from

 

  • blow to the knee

 

          • sudden contraction of the quadriceps muscle.

 

  • The proximal fragment of the patella is pulled superiorly with the quadriceps tendon

 

        • distal fragment remains with the patellar ligament.
      • Bumper fracture
        • a fracture of the lateral tibial condyle
        • caused by an automobile bumper
        • usually associated with a common peroneal nerve injury.
      • Pott’s fracture (Dupuytren’s fracture)
        • a fracture of the lower end of the fibula,
        • often accompanied by
          • fracture of the medial malleolus
          • rupture of the deltoid ligament.
        • It is caused by forced eversion of the foot.

 

  • Pillion fracture
  • T-shaped fracture of the distal femur with displacement of the condyles. It may be caused by a blow to the flexed knee of a person riding pillion on a motorcycle.
  • Fracture of the fibular neck

 

        • cause an injury to the common peroneal nerve, which winds laterally around the neck of the fibula.
        • his injury results in paralysis of all muscles in the anterior and lateral compartments of the leg (dorsiflexors and evertors of the foot),
        • causes  foot drop.

 

  • March fracture (stress fracture)

 

      • fatigue fracture of one of the metatarsals,
      • result from prolonged walking
    • Metatarsal fractures are also common in female ballet dancers when the dancers lose balance and put their full body weight on the metatarsals.