General clinical
features
Although osteoporosis is a generalized disorder of the
skeleton, its major clinical sequelae result form fractures of the vertebrae,
wrist, hip, humerus, and tibia.
The
most frequent symptoms from vertebral body fracture are pain in the back and deformity
of the spine. Pain usually results from collapse of the vertebrae especially in
the dorsal and lumbar regions, is typically acute in onset, and often radiates
around the flank into the abdomen.
Such episodes may occur after sudden
bending, lifting, or jumping movements that may seem to have been trivial; on
some occasions they cannot be related to trauma.
The pain may be increased
even with slight movements such as turning in bed or the valsalva maneuver. Bed
rest may relieve the pain temporarily, only for it to recur in spasms of variable
duration.
Radiation of pain down one leg is uncommon, and symptoms or
sings of spinal cord compression are rare. The acute episodes of pain also may
be accompanied by abdominal distention and ileus.
Thought to be due to
retroperitoneal hemorrhage, but the use of narcotics also contributes to the ileus.
Los of appetite and muscular weakness also may be present.
Episodes
of pain usually subside after several days to a week, and able to resume normal
activities. Although acute pain may be minimal, nagging, deep, dull, uncomfortable
sensations may be localized to area of fracture and brought about by straining
or sudden changes in position.
Patients may be unable to sit up in bed
and have to arise b rolling over on the side and then propping themselves up.
Most patients have disappearance or diminution of pain between episodes of vertebral
body collapse.
Other do not have acute episodes but complain of backache
made worse by standing or sudden movement. Tenderness is common over involved
areas of the spinous processes or rib cage.
Some patients have an associated disease such as osteoarthritis of facet joints
to account for chronic back pain. When collapse fractures of vertebral bodies
do occur, they are usually anterior, producing a wedge-shape deformity and contributing
to loss in height.
This is particularly common in the middorsal region,
where collapse may be unassociated with pain but may result in a dorsal kyphosis
and exaggerated cervical lord sis described as a “dowage’s” or
“widow’s” hump. Postural slumping with increase in existing cures
also contributes to the loss of height.
Scoliosis
is also common. Generalized skeletal pain is uncommon, and between fractures most
patients are free of pain. Although recurrent episodes of vertebral collapse,
increasing spine deformity, and loss of height are common, the course in any one
subject is not predictable, and there may be intervals of several years between
fractures.
Radiologic
features
Prior to fracture and collapse, the Osteoporotic vertebral body shows a decrease
in mineral density, increase in prominence of vertical striations due to a relatively
greater loss of the horizontally oriented trabeculae, and prominence of the end
plates.
The bodies may become increasingly of concave because of weakening
of the subchondral plates, micro fractures, and expansion of the intervertebral
disks, resulting in the so-called codfish vertebrae. When collapse occurs.
It usually produces a decrease in the anterior height of the vertebral body
and irregularity in the anterior cortex. Older compression fractures may show
reactive changes and osteophytes about the margins.
Most Osteoporotic
fractures occur in the middle and lower thoracic and upper lumbar vertebral bodies.
Fractures of isolated vertebral bodies of T4 or higher should suggest malignancy.
Although the cortices of long bones may be thin because of excessive
endosteal resorption, the outer margins are sharp in contrast to the typical effects
of the subperiosteal resortion of hyperparathyroidism.
Pseudo fractures
or looser’s zones do not occur in the absence of osteoporosis form osteomalacia,
but it may be impossible to distinguish osteoporosis from osteomalacia on radiologic
grounds alone.
In the absence of fractures, a standard roentgenograms
are insensitive indicators of bone loss, since as much as 30% decrease in bone
mass may not to be appreciated.
Other
procedures are required to establish whether a given individual has a sufficient
decrease in bone mass to be at risk for fracture. Dual-energy x-ray absorptiometery
is an excellent technique because of its sensitivity.
Ability to scan
the entire skeleton, low radiation exposure, and short scanning time. Single-
and dual-photon absorptiometry and quantitative computed tomography (CT) also
can be detect small (1to 2%) changes in the bone mineral density of he hip and
lumbar spine.
