LOWER EXTREMITIES-BONES

Toe Phalanges

Great Toe (Hallux) has two phalanges, rest of the digits have 3 per, proximal phalanx of the 1st digit is deviated laterally at MTP Joint

Metatarsals

#1-5 articulate with the distal row of the tarsal bones. Bases #2-5 articulate with each other as well

Metatarsal #1

Shorter and thicker than the rest. It articulates with the medial cuneiform bone, This metatarsal has two sesamoid bones located near the head, on the plantar surface

Metatarsal #2

This metatarsal is the longest of the 5. It articulates directly with all the cuneiform bones

Metatarsal #3

This metatarsal articulates with the lateral cuneiform bone

Metatarsal #4

This bone articulates with the cuboid and the lateral cuneiform

Metatarsal #5

The base is expanded to include a tuberosity (also called a styloid process) on the lateral surface. This tuberosity serves as an attachment point for tendons associated with the lower leg. It articulates with the cuboid

Tarsal Bones

7 bones in each foot, proximal row-talus, calcaneus, navicular distal row- medial, middle, lateral cuneiforms, cuboid

Talus

Most superior of the tarsals and sits on the calcaneus. It consists of a head, neck and body, articulates with the navicular (distally), while the body articulates with the calcaneus (inferiorly), the distal tibia (superiorly/proximally) and the malleoli of the tibia and fibula articulate on the sides of the talus (medially and laterally)

Head of Talus

Directed forward and medially. It has a rounded distal portion that articulates with the navicular

Neck of Talus

Separates the head from the body.  It is marked by a deep groove on the inferior surface that runs obliquely medial to lateral called the sulcus tali

Sulcus Tali

Deep groove on the inferior surface of the neck where it separates the anterior and middle facets from the posterior facet. It forms the bony roof of the sinus tarsi

Body of Talus

The dorsal surface is convex and articulates with the distal tibia

Talar Domes

These articulate with the medial and lateral malleoli of the distal tibia and fibula

Anterior Facet of Talus

Articulates with the head of the calcaneus. This facet is concave in shape and usually located most anteriorly.  It is located anterior and lateral to the middle facet

Middle Facet of Talus

Articulates with the sustentaculum tali of the calcaneus

Posterior Facet of Talus

Articulates with the corresponding facet on the upper surface of the calcaneus, and is deeply concave in the direction of its long axis which runs forward and lateral at an angle of about 45 with the median plane of the body

Calcaneus

Largest of the tarsal bones and is oblong in shape. It receives the entire weight of the body

Posterior Surface of Calcaneus

At the inferoposterior aspect, the tuberosity is thickened for the insertion of the Achilles tendon

Lateral Surface of Calcaneus

Flat but contains the peroneal tubercle that projects between the peroneal tendons

Medial Surface of Calcaneus

Shelf of bone which protrudes significantly in a medial direction. The middle facet on the head of the talus rests on this shelf of bone called the sustentaculum tali

Superior Surface of Calcaneus

Has three articular facets that match with the facets of the inferior talus

Sulcus Calcanei

This structure separates the anterior and middle facets from the posterior facet on the superior surface of the calcaneus

Sinus Tarsi

This is a tunnel for the interosseus talocalcaneal ligaments. Runs in a lateral to medial direction with a posterior angle

Navicular

It is located on the medial side of the foot between the proximal and distal row of the tarsals considered an intermediate tarsal bone

Cuneiform Bones

Located in the distal row of the tarsal bones. The medial is the largest while the middle cuneiform is the smallest

Cuboid

Cube-shaped, the cuboid articulates with the bases of metatarsals #4 and 5 and it also articulates medially with the lateral cuneiform as well as the navicular and proximally with the calcaneus

Longitudinal Arch

Runs lengthwise along the sole of the foot. It is formed by the spring and plantar ligaments

Transverse Arch

Formed by the tarsals and bases of the metatarsals and runs crosswise

Tibia

Sits medially and anteriorly in the lower leg, receives the body weight through the femur

Tibia Articulations

Articulates with the distal condyles of the femur to form the knee joint, while the distal end articulates with the talus and contributes to the ankle joint

Tibial Condyles

Flared, thickened ends that form the weight bearing surfaces of the knee joint

Intercondylar Eminence

This is the elevated, bony area on the mid plateau and is formed by the medial and lateral tubercles or spines. These are attachment sites for the ligaments.

Shaft of Tibia

The sharp point of the triangle points anteriorly (towards the shin) can be easily palpated. The lateral edge is roughened for the attachment of the interosseous membraneDistal

Distal End of Tibia

The inferior surface is concave from anterior to posterior to adapt to the trochlear surface of the talus. This construction allows for dorsiflexion and plantarflexion of the ankle joint

Medial Malleolus

The medial extension of the tibia

Distal Tibiofibular Joint

The fibular notch on the lateral surface of the tibia articulates with the distal fibula

FIbula

Sits laterally and more posterior to the tibia, is not a weight-bearing bone and is much thinner in diameter than the tibia

Proximal End of Fibula

Rounded head that articulates on the posterior aspect of the tibia's lateral condyle

Shaft of Fibula

The medial border is roughened for attachment of the interosseous membrane which joins to the tibia

Lateral Malleolus

The distal end of the fibula is slightly expanded to form this

Ankle Joint

Formed by the trochlear surface of the talus, the articular surface of the lateral malleolus of the fibula and the distal articular surface of the tibia

Knee Joint

Largest synovial in the body, it is a synovial bicondylar joint, allowing for hinged joint movement extension and flexion with slight medial and lateral rotation

Patella

Largest sesamoid bone in the body

Menisci

The lateral meniscus is situated between the lateral femoral condyle and lateral tibial condyle. Likewise, the medial meniscus is situated between the medial femoral condyle and medial tibial condyle

Bursae

The knee joint contains 7, they are sac-like structures lined and filled with synovial fluid

Fabella

Sesamoid bones that are located behind the lateral femoral condyle, in the gastrocnemius muscle

Femur

The longest and strongest bone in the body. It articulates proximally with the acetabulum of the pelvis at the hip joint and distally with the tibia at the knee joint

Proximal Femur

Directed proximally, medially and anteriorly. It articulates with the cartilage lined acetabulum of the pelvis

Head of Femur

It is covered with articular cartilage and synovial membrane and has a small depression for attachment of the ligament of the head of the femur (ligamentum teres), referred to as the fovea

Neck of Femur

5cm long and is common site for hip fractures. It runs obliquely from the head of the femur to the shaft at 15-20 degrees posterior and lateral from the midcoronal plane

Angle of Inclination

The neck joins the shaft at an angle of approximately 125 degrees

Greater Trochanter

Situated on the lateral aspect of the femur and is easily palpable. It is the attachment site for several muscles in the gluteal region, including gluteus, piriformis, obturator and gemellus muscles

Lesser Trochanter

Situated medial and slightly posterior. It is the attachment site for the psoas muscle from the lumbar spine

Intertrochanteric Line

The trochanters are connected anteriorly by this

Intertrochanteric Crest

The trochanters are connected posteriorly by this

Femoral Condyles

These condyles are rounded and smooth to articulate inferiorly with the lateral and medial tibial condyles, respectively, and the patella anteriorly

Femoral Epicondyles

Bony elevations that sit on the superior and lateral edges of the articular condyles. They act as attachment points for ligaments of the knee

Intercondylar Notch (Fossa)

Separates the medial and lateral condyles posteriorly. It is an attachment point for ligaments of the knee and is also a common site for knee pathologies