Bones of the lower limb

Dr Idara

Pelvic girdle

• Attaches lower limbs to the spine• Supports visceral organs• Attaches to the axial skeleton by strong

ligaments • Acetabulum is a deep cup that holds the head

of the femur

Pelvic girdle

• Consists of paired hip bones (coxal bones)• Hip bones unite anteriorly with each other• Articulates posteriorly with the sacrum

Pelvic girdle

Hip bones

• Consist of three separate bones in childhood– Ilium, ischium, and pubis

• Bones fuse but retain separate names to describe parts of the hipbone.

• Acetabulum– A deep hemispherical socket on lateral pelvic

surface

ilium

• The ilium is a large flaring bone that forms the superior region of the coxae. It consists of a body and superior wing like portion called the ala

• The broad posterolateral surface is called the gluteal surface

• The auricular surface articulates with the sacrum (sacroiliac joint)

• Major markings include the iliac crests, four spines, greater sciatic notch, iliac fossa, arcuate line .

Lateral view

Medial View

Ischium

• Forms posteroinferior region of the coxal bone• Anteriorly – joins the pubis • Ischial tuberosities– Are the strongest part of the hip bone

Pubis

• Forms the anterior region of the coxal bone• An angulated bone• Lies horizontally in anatomical position• Pubic symphysis (fribrocartilage)

Lateral and Medial Views of the Hip Bone

True and False Pelves

• Bony pelvis is divided into two regions– False (greater) pelvis – bounded by alae of the

iliac bones– True (lesser) pelvis – inferior to pelvic brim• Forms a bowl containing the pelvic organs

True and False Pelves

Comparison of Male and Female Pelvic Structure

• Female pelvis• –Tilted forward, adapted for childbearing• –True pelvis defines birth canal• –Cavity of the true pelvis is broad, shallow,

and has greater capacity

• Male pelvis• –Tilted less forward• –Adapted for support of heavier male build

and stronger muscles• –Cavity of true pelvis is narrow and deep

Thigh

• The region of the lower limb between the hip and the knee

• Femur – the single bone of the thigh– Longest and strongest bone of the body– Ball-shaped head articulates with the acetabulum

Structures of the Femur

Patella

• Triangular sesamoid bone• Imbedded in the tendon that secures the

quadriceps muscles• Protects the knee anteriorly• Improves leverage of the thigh muscles across

the knee

Leg• Refers to the region of the lower limb

between the knee and the ankle• The leg is fixed in permanent pronation• Composed of the tibia and fibula– Tibia – more massive medial bone of the leg• Receives weight of the body from the femur

– Fibula – stick-like lateral bone of the leg• Interosseous membrane- Connects the tibia

and fibula

tibia• Has 2 condyles- medial and lateral• Intercondylar eminence• Shaft has 3 surfaces- medial, lateral and

posterior• Anterior border is most prominent and also

called the shin or shin bone• Extends distally to form the medial malleolus• Posterior surface has a soleal line• Nutrient foramen

fibula

• Lies posteriolateral• Leg is fixed in permanent pronation• Distal end ends in lateral malleolus• Shaft has 3 borders (anterior, posterior and

interosseous) and 3 surfaces (medial, posterior and lateral)

Structures of the Tibia and Fibula

Anterior view

posterior view

The Foot

• Foot is composed of– Tarsus, metatarsus, and the phalanges

• Important functions– Supports body weight– Acts as a lever to propel body forward when

walking– Segmentation makes foot pliable and adapted to

uneven ground

Tarsus

• Makes up the posterior half of the foot• Contains seven (7)bones called tarsals• Talus, calcaneous, cuboid, navicular, 3

cuneiforms• Only the talus articulates with the leg bones.• Body weight is primarily borne by the talus

and calcaneus

Metatarsals

• Consists of five small long bones called metatarsals

• Numbered 1–5 beginning with the hallux (great toe)

• First metatarsal supports body weight

Phalanges of the Toes

• 14 phalanges of the toes– Smaller and less nimble than those of the fingers– Structure and arrangement are similar to

phalanges of fingers– Except for the great toe, each toe has three

phalanges• Proximal, middle, and distal

Bones of the Foot

Bones of the Foot

Bones of the Foot

fractures of the femur• Mostly age and sex related (elderly females <60) due

osteoporosis• Most common site is the neck• Proximal femoral fractures

– Transcervical fracture-femoral neck (avascular necrosis occurs due to retinacular arteries that are cut off from the medial circumflex femoral artery)

– Inter trochanteric fracture• Femoral shaft fracture

– spiral fracture (leads to foreshortening)• Distal femoral fractures

– Fracture of femoral condyles- popliteal artery runs on the posterior surface

Fractures of tibia and fibula

Stress fracture of tibia

Fibula neck fractureDirect trauma as nerve passes superficially around neck of fibula footdrop and loss of eversion

May cause sensory loss over lateral leg and dorsum of foot

Fracture of Lateral malleolus

Fibular malleolar fracture effect-excessive inversion of footCommon in soccer and football players