The
radius is a long bone with a shaft and expanded extremities. The smaller upper
end of the radius has a circular head which articulates with the capitulum of
the ulna. The articular circumference of the head of the radius is bound to the
ulna by an annular ligament within whixh it rotates during the movement of
pronation and
radius is a long bone with a shaft and expanded extremities. The smaller upper
end of the radius has a circular head which articulates with the capitulum of
the ulna. The articular circumference of the head of the radius is bound to the
ulna by an annular ligament within whixh it rotates during the movement of
pronation and
supination of the forearm. The shaft is attached to the ulna by
the interrosseous membrane which stretches between the radius and the ulna
dividing the forearm into interior and posterior compartment.
The
lower extremity of the radius presents an articular surface for the scaphoid
and lunate bones of the wrist. At the lateral end of this surface is a downward
projection of bone called the styloid process which can be felt through the
skin on the lateral aspect while on the medial aspect of the extremity there is
an articular surface for the articulation with the ulna.
lower extremity of the radius presents an articular surface for the scaphoid
and lunate bones of the wrist. At the lateral end of this surface is a downward
projection of bone called the styloid process which can be felt through the
skin on the lateral aspect while on the medial aspect of the extremity there is
an articular surface for the articulation with the ulna.
The Point of Ossification of the Radius
The radius is ossified from three
centers: one for the body, and one for either extremity. That for the body
makes its appearance near the center of the bone, during the eighth week of fetal
life.
centers: one for the body, and one for either extremity. That for the body
makes its appearance near the center of the bone, during the eighth week of fetal
life.
Ossification commences in the lower end between 9 and 26 months of age.
The ossification center for the upper end appears by the fifth year. The upper epiphysis
fuses with the body at the age of seventeen or eighteen years, the lower about
the age of twenty.
The ossification center for the upper end appears by the fifth year. The upper epiphysis
fuses with the body at the age of seventeen or eighteen years, the lower about
the age of twenty.
An additional center sometimes found in the radial tuberosity, appears
about the fourteenth or fifteenth year.
about the fourteenth or fifteenth year.
