Summary Bones and Joints of the Leg and Foot

LEG AND FOOT

TIBIA
● The tibia (shin bone) is the second largest bone in the body.
● Located anteromedially in the leg and nearly parallel to the fibula.
● It flares outward at both ends to increase surface area for articulation and weight
transfer.


PROXIMAL END
● Widened to form medial and lateral condyles:
○ These overhang the shaft medially, laterally, and posteriorly.
○ Together, they form the tibial plateau, a relatively flat superior articular
surface.
● The tibial plateau includes:
○ Two smooth articular surfaces:
■ Medial surface: slightly concave
■ Lateral surface: slightly convex
○ These articulate with the large condyles of the femur.


INTERCONDYLAR REGION
● The two articular surfaces are separated by the intercondylar eminence, which
includes:
○ Medial and lateral intercondylar tubercles
○ Anterior and posterior intercondylar areas (relatively rough)
● These structures:
○ Fit into the intercondylar fossa of the femur
○ Provide attachment sites for the menisci and principal ligaments of the knee
○ Help maintain articular contact between the tibia and femur


OTHER PROXIMAL FEATURES
● On the anterolateral aspect of the lateral tibial condyle:
○ Gerdy tubercle (anterolateral tibial tubercle):
■ Located inferior to the articular surface
■ Serves as the distal attachment of the iliotibial tract (a thickening of the
fascia lata), providing knee stability
● Fibular articular facet:
○ Located posterolaterally on the inferior surface of the lateral condyle
○ Articulates with the head of the fibula

,TIBIAL SHAFT
● The shaft is:
○ Truly vertical in orientation
○ Triangular in cross-section, with three surfaces and three borders:
■ Surfaces: medial, lateral/interosseous, posterior
■ Borders: anterior (most prominent), interosseous, and medial
● The anterior border and adjacent medial surface are:
○ Subcutaneous throughout their length
○ Commonly referred to as the “shin”
○ Prone to bruising due to minimal soft tissue covering


TIBIAL TUBEROSITY
● Located at the superior end of the anterior border
● Serves as the distal attachment for the patellar ligament
○ This ligament connects the inferior margin of the patella to the tibial
tuberosity


DISTAL END
● Smaller than the proximal end
● Flares only medially, forming the:
○ Medial malleolus, which extends inferiorly
● The inferior surface of the shaft and the lateral surface of the medial malleolus:
○ Articulate with the talus
○ Are covered with articular cartilage


INTEROSSEUS BORDER AND MEMBRANE
● The interosseous border:
○ Is sharp along most of its length
○ Provides attachment for the interosseous membrane, connecting the tibia and
fibula
● Inferiorly, the sharp border becomes the:
○ Fibular notch:
■ Accommodates the distal end of the fibula
■ Provides fibrous attachment


POSTERIOR SURFACE BORDER
● On the proximal posterior surface, there is:
○ A soleal line (a rough, diagonal ridge)

, ■ Runs inferomedially to the medial border
■ Indicates the aponeurotic origin of the soleus muscle
■ Located approximately one third down the shaft
● Just below the soleal line is:
○ An oblique vascular groove that leads to:
■ A large nutrient foramen, allowing passage of the:
■ Main artery supplying the proximal tibia and marrow
■ The nutrient canal runs inferiorly into the medullary cavity

, = tibial plateau (flat)
lateral , medial ,
posterior




concave
>
slightly
> slightly convex




Attaches platellar ligament




From interossevos border ; accomodates
head of fibula and fibrous attachment