Human Anatomy
Bones of the Lower Limb
Lower limb osteology for MBBS: hip bone, femur, tibia, fibula and foot bones with fractures and blood supply, mapped to NMC codes AN14.1 to AN14.4.
MedNext Academy | 3 min read
Bones of the Lower Limb
Lower limb osteology for MBBS: hip bone, femur, tibia, fibula and foot bones with fractures and blood supply, mapped to NMC codes AN14.1 to AN14.4.
This chapter surveys the bones and joints of the lower limb, built for weight-bearing and locomotion rather than mobility. It highlights the femoral neck and its blood supply, the weight-bearing tibia, and the tarsal bones that transmit body weight to the ground.
High-yield: Bones of the Lower Limb
- The bones of the lower limb are the hip bone, femur, patella, tibia, fibula, tarsals, metatarsals and phalanges.
- The hip bone is formed by fusion of the ilium, ischium and pubis at the acetabulum.
- The femur is the longest and strongest bone in the body and its neck makes an angle of about 125 degrees with the shaft in the adult.
- The neck of the femur is a common fracture site in the elderly and its blood supply is easily disrupted.
- The femoral head is supplied by retinacular vessels, the artery of the ligamentum teres and the nutrient artery, so neck fractures risk avascular necrosis.
- The greater trochanter gives attachment to the gluteus medius and minimus and the small lateral rotators.
- The patella is the largest sesamoid bone and lies within the quadriceps tendon.
- The tibia bears weight and its subcutaneous anteromedial surface is easily fractured and slow to heal.
- The fibula does not take part in the knee joint and bears little weight but forms the lateral malleolus.
- The talus is the only tarsal bone without muscle attachments and transmits body weight to the foot.
- The calcaneus is the largest tarsal bone and forms the heel, giving attachment to the tendo calcaneus.
- The medial malleolus belongs to the tibia and the lateral malleolus to the fibula.
- The neck of the fibula is closely related to the common peroneal nerve, which is at risk in fractures there.
- The lower end of the femur ossifies from a centre present at birth, used medicolegally as a sign of maturity.
Key lower limb bones
- **Femur:** Longest, strongest bone; neck-shaft angle about 125 degrees; neck fractures risk avascular necrosis of the head.
- **Tibia:** Weight-bearing bone of the leg; subcutaneous anteromedial surface; forms the medial malleolus.
- **Fibula:** Non-weight-bearing; forms the lateral malleolus; neck related to the common peroneal nerve.
- **Talus and calcaneus:** Talus transmits weight and has no muscle attachments; calcaneus forms the heel and takes the tendo calcaneus.
NMC competencies in this chapter
- **AN14.1:** Features and attachments of the hip bone and femur
- **AN14.2:** Features and attachments of the tibia, fibula and patella
- **AN14.3:** Bones of the foot: tarsals, metatarsals and phalanges
- **AN14.4:** Ossification and applied anatomy of lower limb bones
Frequently Asked Questions
Why is a fractured femoral neck dangerous?
The blood supply to the femoral head runs along the neck, so a fracture here can cut off the supply and cause avascular necrosis of the head, especially in the elderly.
Which bone forms the medial malleolus and which the lateral?
The medial malleolus is part of the lower end of the tibia, and the lateral malleolus is part of the lower end of the fibula. Both help form the ankle mortise.
Why is the talus special among tarsal bones?
The talus has no muscle attachments and transmits the entire body weight from the leg to the foot. Its blood supply is precarious, so fractures may lead to avascular necrosis.
Which nerve is at risk at the neck of the fibula?
The common peroneal nerve winds around the neck of the fibula and lies superficially there, so it is easily injured in fractures of the fibular neck, causing foot drop.
Continue reading
MBBSAll Human Anatomy chapters
Continue through the Human Anatomy chapter map.
Continue studying Human Anatomy
Explore clinician-written learning resources, structured revision and practice across the MedNext platform.
Open in the MedNext appSee plans