Tibia

Key Features & Anatomical Relations

The tibia (or shin bone) sits medial to the fibula in the leg. It’s classified as a long bone and includes the following bony features:

- parts: proximal part, body and distal part;

- surfaces: posterior, medial and lateral surfaces, anterior, medial and interosseous borders, and medial and lateral condyles;

- landmarks: tibial tuberosity, tubercle of iliotibial tract, soleal line, fibular notch, and malleolar groove.

More information regarding these and other bony features can be found in the Parts, Surfaces and Landmarks tabs for this bone.

The tibia is located:

- proximal to the talus;

- distal to the femur;

- medial to the fibula.

It articulates with the:

- femur at the medial and lateral femorotibial joints, contributing to the formation of the knee joint;

- fibula at both the superior and inferior tibiofibular joints;

- talus, contributing to the formation of the ankle joint.

Ossification

Ossification of the tibia occurs at three ossification centers, these are found in the:

- body, which appears in utero at the seventh week;

- proximal part, which appears at the time of birth;

- distal part, which appears within the first year.

The ossification centers for the proximal and distal parts of tibia fuse with the body during middle to late adolescence (Standring, 2016).

Variations

In some individuals:

- the proximal part may present an additional intercondylar tubercle;

- an accessory ossicle, known as the os subtibiale, may be present between the distal part of tibia and the talus (Standring, 2016).

The tibia also displays sexual dimorphism, where the mean tibial length is greater in males than in females (Standring, 2016). Additionally, the female tibia is more slender, with a straighter body and smaller and narrower condyles and malleoli (Brzobohatá et al., 2016)

Surface Anatomy

The following bony features of the tibia are relevant to surface anatomy:

- both the medial and lateral condyles are subcutaneous and easily palpated, especially during flexion of the knee joint;

- the tibial tuberosity can be identified by location of the prominence distal to the apex of the patella in the extended knee;

- the tubercle of iliotibial tract can be palpated superolateral to the tibial tuberosity;

- the anterior border, medial surface, and anterior portion of the lateral surface of the tibia are all subcutaneous and can be palpated;

- the medial malleolus is subcutaneous and easily palpated.

List of Clinical Correlates

- Fracture of tibia

- Osgood-Schlatter disease

- Medial tibial stress syndrome (shin splints)

References

Brzobohatá, H., Krajíček, V., Horák, Z. and Velemínská, J. (2016) 'Sexual Dimorphism of the Human Tibia through Time: Insights into Shape Variation Using a Surface-Based Approach', PLoS One, 11(11), pp. e0166461.

Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.