The tibia and ulna Flashcards
What is the tibia?
What are the three areas of interest within the tibia?
The main bone of the lower leg, forms the shin. Second largest bone in the body and it is a key weight bearing structure. Articulates with the femur, patella, fibula and ankle.
Proximal, shaft and distal area.
Describe the structure of the proximal tibia
Widened by medial and lateral condyles. Form surface known as tibial plateau where the knee joint articulates
Underneath lies the intercondylar tubercle. Main area of attachment for ligaments and menisci of the knee. These articulate with the intercondylar fossa of the femur
Describe the structure of the shaft of the tibia?
Prism shaped structure with three borders:
Anterior border- Palpable as the shin, contains the tibial tuberosity attachment site for the patella ligament
Posterior surface- Marked by ridge of bone called soleal line. Diagonal line that forms the origin of the soleus muscle
Lateral border- Also known as interosseous border, bids the tibula and fibula together
What is interosseous access?
Emergency vascular access that allows the administration of fluids, blood products and medications directly into the bone marrow. Typically used in an emergency. Typically administered proximal to medial malleolus or 2-3cm below the tibial tuberosity.
Describe the structure of the distal tibia
Widened to assist with weight bearing. Contains the medial malleolus which articulates with the tarsal bones to form part of the ankle joint. On the posterior surface of the distal tibia there is a groove through which the tendon of tibialis posterior passes.
What are the most common tibular fractures
Tibial shaft- most common fracture, associated with fibular fractures
Proximal tibia- tibial plateau fracture. Condyles may be broken and injury to the menisci and knee ligaments is not uncommon
Ankle- medial malleolus fracture. Ankle is over inverted causing a spiral fracture.
What is the fibula?
What are the three main articulations of the fibula?
Located in the lateral aspect of the leg its main function is to act as an attachment for muscles.
Proximal tibiofibular joint- articulates with lateral condyle of tibia
Distal tibiofibular joint- articulates with fibular notch of the tibia
Ankle joint- articulates with talus bone of the foot
What are the important bony landmarks of the fibula?
Enlarged head with facet for articulation with the lateral condyle of the tibia
Lateral malleolus- can be palpated at the ankle on the lateral side of the leg
What are the two ways the fibula can fracture?
Forced external rotation of the ankle. This force of the talus against the bone causes a spiral fracture of the lateral malleolus
Eversion of the foot, tallus presses against the lateral malleolus causing a transverse fracture
