Tibia bone.

INTRODUCTION

- Medial bone of the leg.

- Stronger bone of the leg.

- Takes part in formation of the knee and ankle joints and thereby helps jn transmission of body weight from femur to the foot.

ANATOMICAL POSITION

- Upper end is broader.

- Anterior border of the shaft is sharp and prominent.

- Medial malleolus projects from medial side of lower end.

PARTS

1. Upper end

Has:-

a. Medial condyl - articulate with medial condyl of femur and has four surface - anterior, medial, lateral, posterior.

b. Lateral condyl - articulate with head of fibula.

c. Tuberosity of tibia - 

has two parts namely :- upper smooth and lower rough part.

2. Shaft

Has -

a. Three borders 

- Anterior, medial and interosseous

b. Three surfaces 

- Medial, lateral and posterior

3. Lower end 

Has -

a. A process known as medial malleolus.

b. Five surfaces (anterior, medial, posterior, lateral and inferior)

ATTACHMENTS

a. Muscles

Origin

1. Tibialis anterior 

2. Soleus

3. Flexor digitorum longus

4. Tibialis posterior

Insertion

1. Sartorius

2. Semi membranosus

3. Gracilis

4. Semi tendinosus

5. Popliteus

b. Ligaments

1. Capsular ligament of knee joint.

2. Deeper fibres of tibial collateral ligament.

3. Capsular ligament of superior tibiofibular joint.

4. Tendon of popliteus.

5. Anterior cruciate ligament.

6. Posterior cruciate ligament.

7. Tibial collateral ligament.

8. Deltoid ligament.

9. Interosseous tibiofibular ligament.

10. Capsular ligament of ankle joint.

11. Ligamentum patellae.

c. Meniscus

1. Posterior horn of lateral meniscus.

2. Anterior horn of lateral meniscus.

3. Posterior horn of medial meniscus

4. Anterior horn of the medial meniscus.

d. Other structures

1. Medial patellar retinaculum.

2. Superior extensor retinaculum.

3. Iliotibial tract.

CLINICAL ANATOMY 

1. Lower one third of tibia has a comparatively poor blood supply, so non union fracture is common in the lower end of tibia.

2. Inversion injury results in transverse fracture of medial malleolus at base.

3. Upper end of tibia is one of the commonest sites for one osteomyeletis

RELATIONS - 

Nerve 

1. Deep peroneal nerve.

Blood supply

2. Posterior tibial artery.