L

laminectomy A surgical OPERATIONto remove a
segment of vertebra (BONEof the spine) to relieve
pressure against the SPINAL CORDor a spinalNERVE
root. Laminectomy treats neurologic symptoms
arising from HERNIATED NUCLEUS PULPOSUS(herniated
or slipped disk), CERVICAL SPONDYLOSIS, and SPINAL
STENOSIS. When laminectomy is the appropriate
therapeutic choice, it has a fairly high success rate
for relieving symptoms (such as PAIN, weakness,
and numbness in the leg) and allowing the person
to return to regular activities. However, it is
important to first consider all other therapeutic
options as the rate of success for back surgery is
highly variable.
Laminectomy is an OPEN SURGERYon the back
performed under general ANESTHESIA. An orthope-
dic surgeon or a neurosurgeon may perform the
operation. The surgeon makes a long incision (five
to seven inches) along the spine at the site of the
impingement; separates the soft tissue structures
from the vertebra to expose the bone; and
removes a lamina, one of the flat segments of the
vertebral arch. Depending on the cause of the
impingement and the overall health of the verte-
brae (whether there is progressive deterioration
such as is common with spinal stenosis), the sur-
geon may choose also to fuse the operated verte-
bra to an adjacent healthy vertebra for stability.
Most people stay in the hospital up to three days
after the operation. Recuperation and return to
normal activities takes six to eight weeks.
The risks of laminectomy include excessive
bleeding during surgery, postoperative INFECTION,
continued symptoms after HEALING, and sensory dis-
turbances resulting from surgical injury to the
spinal nerve root. When the cause of the nerve
compression was deterioration of the vertebra due
to a progressive condition such as OSTEOARTHRITIS,

further damage may occur to the same vertebra or

other vertebrae. About 70 percent of people experi-

ence full relief from their symptoms and return to

work and recreational activities without restriction.

See also BACK PAIN; SCIATICA; SPINAL NERVES; SUR-

GERY BENEFIT AND RISK ASSESSMENT.

ligament A cordlike structure of tough connec-

tive tissue that binds bones together at joints. Lig-

aments are vulnerable to injury from stretching,

which can cause them to tear. Such a ligament

injury is a sprain. Most sprains heal with conser-

vative treatment, though some (notably complete

tears) require surgery to repair them. Ligaments

may also join or support organs and structures

other than bone, such as the round ligaments in

the pelvis that suspend the UTERUS within the

abdominal cavity.

See also BONE; JOINT; MUSCLE; SPRAINS AND STRAINS;

TENDON.

lipoma A benign (noncancerous) soft tissue

tumor. Lipoma is the most common type of tumor.

It arises from adipocytes—fat cells—though can

develop in any kind of tissue. Lipomas are particu-

larly common in the MUSCLE, appearing as a small

painless lump. A lipoma near the surface of the

SKINfeels soft and fairly well defined. Lipoma does

not hurt or become cancerous and requires no

treatment unless it becomes larger than five cen-

timeters. Large lipomas may be cosmetically unac-

ceptable or cause irritation to the surrounding

tissue. The doctor may choose to biopsy or remove

a lipoma that occurs in the BREASTor COLON, to be

certain of the diagnosis as other kinds of breast

and colon tumors may be malignant (cancerous).

Lipomas have a tendency to recur after surgery to

remove them.

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