1. The tibia (os tibia) and fibula (os fibula) are the leg bones. Because the tibia bears more weight, it is thicker and stronger than the fibula.
2. At its proximal end, the tibia joins with the condyles of the femur to form the knee joint. The lateral tibial condyle also articulates with the head of the fibula to form the superior tibiofibular joint.
At the distal end of the tibia, a medial depression accommodates the lower fibula to form the inferior tibiofibular joint. The distal tibia also articulates with the proximal portion of the talus bone (= a foot carpal bone) to form the ankle joint.
3. (Condylus lateralis) - a lateral expansion at the tibia's proximal end. A fibrocartilage pad (= lateral meniscus) supports the condyle's flatteded superior surface so it can smoothly articulate with the lateral condyle of the femur. The iliotibial tract attaches to the front of the tibial condyle and the short head of the biceps femoris attaches to the back.
4. (Condylus medialis) - a medial expansion at the tibia's proximal end that is supported by the medial meniscus and articulates with the medial condyle of the femur. The semimembranosus muscle attaches to the back of the tibial condyle.
5. (Eminentia intercondylaris) - an elevated area between the condyles that contains the bump-like raised medial edges of each condyle. Roughened depressions located anterior and posterior to the eminence are attachment sites for the anterior and posterior cruciate ligaments and the central tips of the medial and lateral menisci.
6. (Tuberositas tibiae) - a raised, roughened area on the anterior surface of the bone just inferior to the condyles. This area is also called is the tuberosity of the tibia. It is an attachment point for the patellar ligament, which serves as the distal tendon of the quadriceps muscle group.
7. (Margo anterior) - the sharp-edged, anterior ridge that extends longitudinally from the tuberosity to medial malleolus. It is most prominent along the proximal two-thirds of bone. The deep fascia of the leg attaches here.
8. (Margo interosseus) - the sharp-edged lateral margin that serves as the attachment site for the interosseous membrane. The connective tissues of the interosseous membrane separate the posterior and anterior muscles into anatomical compartments.
9. (Malleolus medialis) - a prominent downward projection at the distal end of the tibia, on the medial side. It articulates with the talus bone to form the medial portion of the ankle joint. The medial malleolus also serves as the proximal attachment for the deltoid (medial collateral) ligament, which binds the tibia to the calcaneus and talus bones of the foot.
10. (Incisura fibularis) - an indentation at the distal end of the tibia on the lateral side of the bone. It articulates with the the fibula to form the inferior tibiofibular joint.
11. (Caput fibulae) - a small, knob-like extension from the proximal end of the fibula that articulates with the lateral condyle of tibia. The head is an attachment site for the soleus, bicep femoris (long head), fibularis (peroneus) longus, and extensor digitorum longus muscles and the fibular (lateral) collateral ligament.
12. (Margo interosseus) - the sharp-edged medial margin of the fibula that serves as the other attachment site for the interosseous membrane.
13. (Malleolus lateralis) - a pyramidal-shaped, downward projection at the distal end of the fibula. The medial malleolus, which extends more inferiorly than the lateral malleolus, articulates with the tibia and the talus bones of the foot to form the lateral portion of the ankle. Several ligaments attach the lateral malleolus to the tibia, talus, and calcaneus bones.