A hip osteotomy is performed under general anesthesia. Once the
patient has been anesthetized, the surgeon makes an incision to
expose the hip joint. The surgeon then proceeds to cut away
portions of damaged bone and tissue to change the way they fit
together in the hip joint. This part of the procedure may
involve removing bone from the femoral head or from the
acetabulum, allowing the bone to be moved slightly within the
joint. By changing the position of these bones, the surgeon
tries to shift the brunt of the patient's weight from damaged
joint surfaces to healthier cartilage. He or she then inserts a
metal plate or pin to keep the bone in its new place and closes
the incision.
There are different hip osteotomy procedures, depending on the
type of bone correction required. Two common procedures are:
Varus Rotational Osteotomy (VRO), also called a varus
derotational osteotomy (VDO)
In some patients, the femoral
neck is too straight and is not angled far enough toward the
acetabulum. This condition is called femoral neck valgus or just
plain valgus. The VRO procedure corrects the shape of the
femoral neck. In other patients, the femoral neck is not
straight enough, in which case the condition is referred to as a
femoral neck varus.
Pelvic Osteotomy
Many hip disorders are caused by a deformed acetabulum that
cannot accommodate the femoral head. In this procedure, the
surgeon redirects the acetabular cartilage or augments a
deficient acetabulum with bone taken from outside the joint.
A physical examination performed by a pediatrician or an
orthopaedic surgeon is the best method for diagnosing
developmental dysplasia of the hip. Other aids to diagnosis
include ultrasound examination of the hips during the first six
months of life. An ultrasound study is better than an x ray for
evaluating hip dysplasia in an infant because much of the hip is
made of cartilage at this age and does not show up clearly on x
rays. Ultrasound imaging can accurately determine the location
of the femoral head in the acetabulum, as well as the depth of
the baby's hip socket. An x-ray examination of the pelvis can be
performed after six months of age when the child's bones are
better developed. Diagnosis in adults also relies on x ray
studies.
Immediately following a hip osteotomy, patients are taken to the
recovery room where they are kept for one to two hours. The
patient's blood pressure, circulation, respiration, temperature,
and wound drainage are carefully monitored. Antibiotics and
fluids are given through the IV line that was placed in the arm
vein during surgery. After a few days the IV is disconnected; if
antibiotics are still needed, they are given by mouth for a few
more days. If the patient feels some discomfort, pain medication
is given every three to four hours as needed.
Patients usually remain in the hospital for several days after a
hip osteotomy. Most VRO patients also require a body cast that
includes the legs, which is known as a spica cast. Because of
the extent of the surgery that must be done and healing that
must occur to restore the pelvis to full strength, the patient's
hip may be kept from bearing the full weight of the upper body
for about eight to 10 weeks. A second operation may be performed
after the patient's pelvis has healed to remove some of the
hardware that the surgeon had inserted. Full recovery following
an osteotomy usually takes longer than with a total hip
replacement; it may be about four to six months before the
patient can walk without assistive devices.
Although complications following hip osteotomy are rare, there
is a small chance of infection or blood clot formation. There is
also a very low risk of the bone not healing properly, surgical
damage to a nerve or artery, or poor skin healing.
Full recovery from an osteotomy takes six to 12 months. Most
patients, however, have good outcomes following the procedure.
Alternatives
One alternative is to postpone surgery, if the patient's pain
can be sufficiently controlled with medication to allow
reasonable comfort, and if the patient is willing to accept a
lower range of motion in the affected hip.
Surgical alternatives to a hip osteotomy include:
Total hip replacement
Total hip replacement is an operation designed to replace the
entire damaged hip joint. Various prosthetic designs and types
of procedures are available. The procedure involves surgical
removal of the damaged parts of the hip joint and replacing them
with artificial components made from ceramic or metal alloys.
The bearing surface is usually made from a durable type of
polyethylene, but other materials including ceramics, newer
plastics, or metals may be used.
Arthrodesis or Fusing the Hip Joint
This procedure is rarely performed as of 2003, but is
considered particularly effective for younger patients who are
short in stature and otherwise healthy. Arthrodesis relieves
pain by fusing the femoral head to the acetabulum. It has none
of the limitations that a joint replacement or other procedure
imposes on the patient's activity level. An arthrodesis is
especially suited for patients with strong backs and no other
symptoms. The procedure generally requires internal fixation
with a plate and screws. The patient may be immobilized in a
cast while healing takes place. An arthrodesis can be converted
to a total hip replacement at a later date.
Pseudarthrosis
This procedure is also called a Girdlestone operation. A
pseudarthrosis involves removing the femoral head without
replacing it with an artificial part. It is performed in
patients with hip infections and those whose bones cannot
tolerate a reconstructive procedure. Pseudarthrosis leaves the
patient with one leg shorter and usually less stable than the
other. After this procedure, the patient almost always needs at
least one crutch, especially for long-distance walking.
