Pelvis & lower limb · Leg
Tibia
The tibia is the medial and larger of the two leg bones. Above, its condyles articulate with the femur at the knee; below, its inferior surface and medial malleolus articulate with the talus at the ankle; and it is joined to the fibula at both ends and by the interosseous membrane.
- Latin (TA)
- Tibia
- Type
- Long bone: a triangular shaft
- Side
- Paired — right and left
- Model size
- 35.8 cm longest
Showing a right bone. Rotate it to inspect every surface; switch sides to practise siding.
3D model: Z-Anatomy (CC BY-SA 4.0), derived from BodyParts3D © DBCLS (CC BY-SA 2.1 JP). Adapted by PharmaWallah. Credits & licence
Landmarks
27 of 27 marked on the modelTap a landmark to find it on the bone and read what it is.
The larger, medial expansion of the upper end.
Where: At the upper end, on the medial side.
Why it matters: Its upper surface articulates with the medial femoral condyle (through the medial meniscus); semimembranosus inserts on its back.
Related: Knee joint, semimembranosus, tibial collateral ligament.
Marked on the model at the point Z-Anatomy places this label.
The lateral expansion of the upper end.
Where: At the upper end, on the lateral side.
Why it matters: Its upper surface articulates with the lateral femoral condyle; its underside carries the facet for the head of the fibula.
Related: Knee joint, superior tibiofibular joint.
Marked on the model at the point Z-Anatomy places this label.
The flat upper surface of the tibia, formed by the articular surfaces of the two condyles.
Where: The top of the bone.
Why it matters: Bears the femoral condyles through the menisci; a common site of fracture from falls and side impacts.
Marked on the model at the point Z-Anatomy places this label.
A raised area between the two articular surfaces of the plateau, carrying two small tubercles.
Where: In the middle of the tibial plateau.
Why it matters: Separates the anterior and posterior intercondylar areas, where the cruciate ligaments and the horns of the menisci attach.
Marked on the model at the point Z-Anatomy places this label.
The non-articular area in front of the intercondylar eminence.
Where: On the upper surface, between the condyles, in front.
Why it matters: Attachment of the anterior cruciate ligament and the anterior horns of the menisci.
Related: Anterior cruciate ligament.
Viva: Where does the anterior cruciate ligament attach on the tibia?
Marked on the model at the point Z-Anatomy places this label.
The non-articular area behind the intercondylar eminence.
Where: On the upper surface, between the condyles, behind; it slopes down onto the back of the bone.
Why it matters: Attachment of the posterior cruciate ligament and the posterior horns of the menisci.
Related: Posterior cruciate ligament.
Marked on the model at the point Z-Anatomy places this label.
A small, flat, round facet on the underside of the lateral condyle.
Where: On the posterolateral underside of the lateral condyle.
Why it matters: Articulates with the head of the fibula at the superior (proximal) tibiofibular joint; it is lateral, which helps side the bone.
Marked on the model at the point Z-Anatomy places this label.
A rough, raised area on the front of the upper end.
Where: Anteriorly, below the condyles, at the top of the anterior border.
Why it matters: Insertion of the patellar ligament, through which quadriceps extends the knee; it faces forwards, so it orients the bone.
Related: Patellar ligament.
Viva: What inserts into the tibial tuberosity?
Marked on the model at the point Z-Anatomy places this label.
The triangular middle part of the tibia, narrowest in its lower part.
Where: Between the condyles and the lower end.
Why it matters: Carries body weight down to the ankle; its medial surface is subcutaneous, so shaft fractures are often open.
Marked on the model at the point Z-Anatomy places this label.
A sharp crest down the front of the shaft.
Where: From the tibial tuberosity down to the front of the medial malleolus.
Why it matters: Felt under the skin as the shin; it faces forwards and orients the bone.
Marked on the model at the point Z-Anatomy places this label.
The sharp lateral border of the shaft.
Where: Along the lateral side of the shaft, facing the fibula.
Why it matters: Attachment of the interosseous membrane, which binds the tibia to the fibula and separates the anterior and posterior compartments.
Marked on the model at the point Z-Anatomy places this label.
The broad, flat surface between the anterior and medial borders.
Where: On the anteromedial side of the shaft, directly under the skin.
Why it matters: Subcutaneous, so easily felt and easily injured; sartorius, gracilis and semitendinosus insert on its upper part (pes anserinus).
Related: Sartorius, gracilis, semitendinosus, tibial collateral ligament.
Marked on the model at the point Z-Anatomy places this label.
The surface between the anterior and interosseous borders.
Where: On the anterolateral side of the shaft.
Why it matters: Its upper part gives origin to tibialis anterior.
Related: Tibialis anterior.
Marked on the model at the point Z-Anatomy places this label.
The surface between the interosseous and medial borders.
Where: On the back of the shaft.
Why it matters: Popliteus inserts above the soleal line; below it arise flexor digitorum longus and tibialis posterior.
Marked on the model at the point Z-Anatomy places this label.
An oblique rough line on the upper posterior surface.
Where: Running downwards and medially across the upper back of the shaft, from below the fibular facet to the medial border.
Why it matters: Origin of part of soleus; popliteus inserts into the triangular area above it.
Related: Soleus, popliteus.
Viva: Which muscle inserts above the soleal line?
Marked on the model at the point Z-Anatomy places this label.
A stout process projecting downwards from the medial side of the lower end.
Where: At the lower end, medially; it forms the bony bump on the inner side of the ankle.
Why it matters: Forms the medial wall of the ankle socket and gives attachment to the deltoid (medial) ligament; its position is the main guide to the side.
Related: Ankle joint, deltoid ligament.
Viva: Which ligament is attached to the medial malleolus?
Marked on the model at the point Z-Anatomy places this label.
A triangular notch on the lateral side of the lower end.
Where: At the lower end, laterally.
Why it matters: Receives the lower end of the fibula at the inferior (distal) tibiofibular joint, a fibrous joint (syndesmosis); being lateral, it helps side the bone.
Marked on the model at the point Z-Anatomy places this label.
The smooth articular underside of the lower end.
Where: The lower surface of the distal end.
Why it matters: Articulates with the upper surface (trochlea) of the talus at the ankle joint.
Related: Ankle joint, talus.
Marked on the model at the point Z-Anatomy places this label.
Classification & region
Long bone: a triangular shaft (body) with two expanded ends. It is the larger, medial and weight-bearing bone of the leg.
- Proximal end
- Expanded into the medial and lateral condyles, whose flat upper articular surfaces (the tibial plateau) are separated by the intercondylar area and eminence; the tibial tuberosity lies in front.
- Shaft (body)
- Triangular in cross-section, with anterior, medial and interosseous (lateral) borders and medial, lateral and posterior surfaces; the medial surface lies under the skin.
- Distal end
- Smaller than the upper end; it projects medially as the medial malleolus, has the fibular notch laterally, and an inferior articular surface for the talus.
Hold it in the anatomical position
- Put the broad end with the flat condyles at the top and the narrower end with the medial malleolus at the bottom.
- Turn the sharp anterior border (the shin) and the tibial tuberosity forwards.
- The medial malleolus is then on the medial side, and the fibular notch at the lower end is on the lateral side.
Right or left? Side determination
- Identify the upper end: the expanded end with two flat condyles.
- Turn the tibial tuberosity and the sharp anterior border forwards, away from you, as if the bone were in your own leg.
- Find the medial malleolus at the lower end: it lies on the medial side, the side towards the midline.
- Check: the fibular notch (lower end) and the fibular articular facet (under the lateral condyle) are on the opposite, lateral side.
- Held this way, a medial malleolus on your left means a right tibia.
Check yourself: switch the 3D model to “Left bone” and apply the same steps.
Articulations
- With the femur at the Knee joint (tibiofemoral part) — Superior articular surfaces of the medial and lateral condyles (tibial plateau).
- With the fibula (head) at the Superior (proximal) tibiofibular joint — Fibular articular facet on the lateral condyle.
- With the fibula (lower end) at the Inferior (distal) tibiofibular joint (syndesmosis) — Fibular notch.
- With the talus at the Ankle (talocrural) joint — Inferior articular surface and the articular facet of the medial malleolus.
Muscle and ligament attachments
| Structure | Type | Where on the bone |
|---|---|---|
| Patellar ligament (quadriceps femoris) | insertion | Tibial tuberosity |
| Sartorius, gracilis and semitendinosus (pes anserinus) | insertion | Upper part of the medial surface |
| Semimembranosus | insertion | Posterior surface of the medial condyle |
| Iliotibial tract | insertion | Tubercle of the iliotibial tract on the lateral condyle |
| Popliteus | insertion | Posterior surface above the soleal line |
| Soleus | origin | Soleal line and the medial border (also from the fibula) |
| Tibialis anterior | origin | Lateral condyle and upper part of the lateral surface |
| Tibialis posterior | origin | Posterior surface (lateral part, below the soleal line) and interosseous membrane |
| Flexor digitorum longus | origin | Posterior surface (medial part, below the soleal line) |
| Anterior cruciate ligament | ligament | Anterior intercondylar area |
| Posterior cruciate ligament | ligament | Posterior intercondylar area |
| Medial and lateral menisci (horns) | ligament | Anterior and posterior intercondylar areas |
| Tibial collateral ligament | ligament | Medial condyle and upper medial surface |
| Interosseous membrane | ligament | Interosseous border |
| Deltoid (medial) ligament of the ankle | ligament | Medial malleolus |
Functions
- Transmits body weight from the femur to the talus; it is the weight-bearing bone of the leg.
- Forms the upper and medial parts of the ankle socket.
- Gives attachment to muscles of the thigh (via the patellar ligament and pes anserinus) and of the leg.
- With the fibula and interosseous membrane, separates the anterior and posterior compartments of the leg.
Clinical & practical relevance
- Because the medial surface lies directly under the skin, fractures of the shaft are often open (compound).
- The tibial tuberosity can become painful and prominent in adolescents who play sport (Osgood–Schlatter disease), from the pull of the patellar ligament.
- Fractures of the tibial plateau, often of the lateral condyle, can follow a blow to the side of the knee.
- In young children the flat upper medial surface is a site for intraosseous needle access when veins cannot be found in an emergency.
- The great saphenous vein passes in front of the medial malleolus, where it can be found reliably.
- Ankle fractures can break the medial malleolus, the lateral malleolus and the posterior margin of the tibia ('trimalleolar' fracture).
Identification tips
- Malleolus MEDIAL on the TIBIA; the fibula forms the LATERAL malleolus.
- The fibula attaches to the tibia on its lateral side at both ends: the facet under the lateral condyle and the fibular notch.
- Pes anserinus: 'Say Grace before Tea' — Sartorius, Gracilis, semiTendinosus, from front to back.
Common student mistakes
- Saying the fibula articulates with the femur: only the tibia does at the knee.
- Placing the soleal line on the front of the tibia: it is on the back.
- Confusing the anterior and posterior intercondylar areas when attaching the cruciates: anterior cruciate to the anterior area.
- Siding the bone with the medial malleolus pointing laterally because the lower end was taken for the upper end.
Common exam questions
How do you determine the side of a tibia?Show answer
Condyles up, tibial tuberosity and anterior border forwards; the medial malleolus is medial, the fibular notch lateral.
Name the structures attached to the intercondylar area of the tibia.Show answer
ACL and the anterior horns of the menisci in the anterior area; PCL and the posterior horns in the posterior area.
What is the pes anserinus?Show answer
The combined insertion of sartorius, gracilis and semitendinosus on the upper medial surface of the tibia.
Describe the soleal line and its attachments.Show answer
An oblique line on the upper posterior surface; soleus arises from it and popliteus inserts above it.
Why are tibial shaft fractures often open?Show answer
Because the medial surface of the tibia is subcutaneous, with no muscle covering it.
Name the joints formed by the tibia.Show answer
Knee (with the femur), superior and inferior tibiofibular joints (with the fibula), and the ankle (with the talus).
Which tendons lie in the malleolar groove behind the medial malleolus?Show answer
Tibialis posterior, with flexor digitorum longus.
Revision summary
- Medial, weight-bearing long bone of the leg.
- Upper end: two condyles, plateau, intercondylar eminence, tibial tuberosity in front.
- Shaft: sharp anterior border and subcutaneous medial surface; soleal line behind.
- Lower end: medial malleolus medially, fibular notch laterally, inferior articular surface for the talus.
- ACL to the anterior intercondylar area, PCL to the posterior.
- Joints: knee, superior and inferior tibiofibular, ankle.
Test yourself on the tibia
Spotting questions on bones, sides and landmarks — untimed, with explanations.
Joints of the tibia
References
- Drake RL, Vogl AW, Mitchell AWM. Gray's Anatomy for Students. 5th ed. Philadelphia: Elsevier; 2023.
- Moore KL, Dalley AF, Agur AMR. Moore's Clinically Oriented Anatomy. 9th ed. Philadelphia: Wolters Kluwer; 2023.
- Federative International Programme for Anatomical Terminology (FIPAT). Terminologia Anatomica. 2nd ed. FIPAT.library.dal.ca; 2019. fipat.library.dal.ca/TA2
- Kervyn G, Zielinski M, Vinent L, et al. Z-Anatomy: the libre 3D atlas of anatomy. Models derived from BodyParts3D, The Database Center for Life Science (CC BY-SA 2.1 JP). CC BY-SA 4.0. www.z-anatomy.com/
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