Total Hip Replacement
Arthritis of the hip
Hip replacement surgery
Anaesthesia for hip
replacement surgery
Possible
complications of hip replacement surgery
Activity after hip
replacement surgery
Arthritis of the hip
The hip is
a ball and socket joint. The ball is formed by the upper end of the femur (thigh
bone), and the socket by a part of the pelvis called the acetabulum.
The ends of the bones are covered with a smooth layer of cartilage.
Normal cartilage allows nearly frictionless and pain-free movement. When the cartilage is
damaged or diseased by arthritis, joints become stiff and painful. Arthritis of the
hip may affect around 2% of the population. Some people are born with a shallow or
dislocated hip and others may have an injury to the hip or pelvis which can cause
arthritis. Other people with relatively long legs may be more prone to arthritis and there
is also a familial tendency.
Osteoarthritis
Osteoarthritis is the result of wear and tear on the joint.
The normal cartilage lining is gradually worn away and the underlying bone exposed. It may
be many years before the damage to the joint becomes noticeable. Pain and stiffness are
the usual problems associated with osteoarthritis. Pain may be felt in the groin or
over the hip, and sometimes runs down to the knee.
Inflammation
Inflammation of the joints can be caused by a variety of conditions,
the commonest of which is rheumatoid arthritis. Inflammation causes damage to the
cartilage lining of the joints. This causes arthritis which is often more widespread than
osteoarthritis, and typically affects several joints. This kind of arthritis can affect
people when they are relatively young and may cause severe disability.
Treatment of arthritis
If the arthritis is inflammatory in nature, then a specific diagnosis
should be sought. Blood tests and other tests can help to determine the type of
arthritis involved. Anti-inflammatory and other drugs may be helpful .
For patients with osteoarthritis, it is important to remain flexible
and to maintain as much movement as possible. Analgesics (pain killers) can help
patients to maintain activity. Many modern pain killers also have an anti-inflammatory
effect, which may be beneficial in arthritis.
If arthritis is severe and significantly affects activity, then joint
replacement surgery may be appropriate.
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Hip Replacement
Surgery
Joint replacement is a common surgical procedure with a high success
rate. In an arthritic hip, the damaged ball (the upper end of the femur) is
replaced by a metal or ceramic ball attached to a metal stem fitted into the
femur, and a plastic or ceramic socket is implanted into the pelvis, replacing
the damaged socket. 25 years ago, Sir John Charnley developed a stainless
steel stem which articulated with a plastic cup. Both components were held in
place by a plastic 'cement'. This was one of the earliest successful hip replacement
systems.
Metals used, include stainless steel, alloys of cobalt and
chrome, and titanium. Wear resistant polyethylene (plastic) or ceramic are used
for socket replacement. The plastic (or ceramic) liner may be implanted directly
into the pelvis, or may be fitted into a metal socket. New ceramics
and plastics with improved wear characteristics are currently being developed.
A plastic bone cement may be used to anchor the prosthesis into the bone. Joint
replacements also can be implanted without cement when the prosthesis is designed
to fit and lock into the bone directly.
Hip Replacement options
Total Hip Replacement (THR; also called total
hip arthroplasty; THA)
The hip socket and ball of femur are replaced, with
a metal or ceramic ball on a metal stem fitted into a cup with a plastic or
ceramic liner.
Revision of Hip Replacement
A re-operation on a previously performed hip replacement
which has failed, worn or become loose or infected. Part or all of the previous
implant is removed and replaced with a new one.
Bilateral Hip Replacement
Both hips are replaced simultaneously. This operation
has a longer recovery time and generally requires a higher level of fitness
pre-operatively.
Hip resurfacing (Birmingham hip
resurfacing; BHR)
A relatively new kind of hip replacement in which
the ball of the femur is "resurfaced" with a metal shell rather than
being removed and replaced. This preserves more of the patient's own bone
and produces a more anatomical load bearing on the femur. The socket is
replaced as in a traditional hip replacement procedure, without cement.
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Anaesthesia
for hip replacement surgery
Hip replacement can be performed under general, spinal or
epidural anaesthesia. A combination of techniques is often used.
General anaesthetic
The patient is asleep throughout the
procedure. A breathing machine (ventilator) may be used to assist the patient's
breathing during anaesthesia. Many patients feel drowsy or groggy after a general
anaesthetic. The use of newer anaesthetic drugs has significantly decreased the
occurrence of post-operative nausea and vomiting.
Spinal block or epidural block
These techniques use local anaesthetic to block the passage of
nerve impulses, including pain, in the spinal cord. The block can be positioned at
various spinal levels, but the patient generally has no feeling from the waist
down. The patient is usually sedated during the procedure, but a ventilator is
usually not required for this kind of anaesthetic. It thereby can lower some of the
risks of general anaesthetic. Depending on the medications used for the block, the period
of pain relief after surgery can be prolonged for several hours, reducing the need for
pain medication after surgery. Because these blocks provide temporary loss of sensation
below the waist, a urinary catheter (tube into the bladder to drain urine) is often
inserted.
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Possible Complications of hip replacement surgery
Any surgical procedure carries various risks and potential
complications. Although uncommon in joint replacement surgery, the following complications
sometimes occur.
Blood Loss Requiring a Blood Transfusion
In any joint replacement surgery, some blood loss
will occur. Occasionally a blood transfusion may be required. Precautions will be taken
during the operation to minimise blood loss. Some patients may be given the option to
donate their own blood pre-operatively.
Infection
Any surgery performed via an incision in the skin
carries the risk of infection. Many precautions are taken during your surgery to minimise
the risk of infection. Intravenous antibiotics are usually given during
surgery to help prevent infection. The operating room is also equipped with special air
flow devices that minimise bacteria in the air.
Blood Clotting in the Legs (Deep Venous
Thrombosis (DVT))
The circulation to the legs may be decreased during
hip replacement surgery due to immobilisation of the legs. Decreased movement of blood
through the veins (venous stasis) can cause the blood to clot. Blood thinning medication
is used to help minimise this risk, but a small percentage of patients
still develop blood clots in the leg.
Blood Clot Moving to the Lungs (Pulmonary
Embolism (P.E.))
Occasionally, blood clots that form in the legs may
become detached and travel to the circulation in the lungs. This complication, although
extremely rare, can be life threatening. Symptoms include chest pain and shortness of
breath.
Nerve Injury
Any incision can result in damage to the sensory
nerves in the area of the incision. Significant nerve damage, which may cause loss of
muscle function, can occur after hip replacement. This type of injury is very rare and is
most common when lengthening the hip more than one inch (such as in surgery for congenital
hip deformity or revision total hip replacement). Nerve injuries of this type can lead to
a 'foot drop" or the inability to raise the ankle or toe.
Hip Dislocation
Dislocation occurs when the ball of the hip
joint pops out of the socket. It is uncommon and usually preventable after hip
replacement surgery. Prevention depends largely on patient education and care in the
postoperative period.
Hip dislocation can occur at any time after surgery.
However, it is most likely to occur within the first six weeks post-operatively. The
muscles around the hip socket are healing during this time. They are not strong enough to
hold the ball in the socket when the hip joint is under certain kinds of stress. Movements
and positions that produce these stresses should be avoided in the post-operative period.
Hip dislocation is usually accompanied by a pop or
noise, and by pain the groin and/or buttocks. The affected leg will feel and look either
much shorter or occasionally much longer. The foot may be rotated either outward or
inward. Patients are often unable to bear weight or walk on the affected hip. A hip
dislocation is not life threatening but should be treated promptly.
Dislocation is confirmed by x-ray. If
the hip is dislocated, it is usually reduced (put back into position) under general
anaesthetic This procedure is called a closed reduction; a surgical incision is not
required. Usually, you are released to go home that same day.
Very rarely, the hip cannot be relocated by closed
reduction and an open reduction is required. The procedure is done through an incision and
requires a few days in hospital.
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Activity
after a Hip Replacement
Very few restrictions to activity are required following
total hip replacement surgery. Running or jumping activities or lifting heavy
weights are not recommended. Walking, golf, bowling, swimming and riding a bike are
not restricted.
Recovery time after a Hip Replacement
Patients are usually standing or sitting at the bedside the
day after hip replacement surgery. By the time patients are discharged, they should be
able to get in and out of bed and walk to the bathroom. Stair climbing is a particular
issue after hip replacement surgery, as it may result in dislocation if the correct
procedure is not observed.
Most patients are around 80% recovered by six weeks
after surgery. They will continue to improve more gradually over the next three to six
months. Recovery varies from person to person depending on their level of pain and
activity before their surgery.
Bilateral hip replacement procedures
Occasionally, the patient and surgeon may decide that having
both hips replaced at the some time is an acceptable option. The benefits are that the
patient only has to come to the hospital one time, have one surgery and one recovery time.
The initial recovery will be slower and physiotherapy will be more difficult at first. The
patient will be in the hospital up to 3 or 4 days longer than if only one joint was
replaced. If both hips are replaced, dislocation precautions must be
observed on both hips. The patient will not be able to lie on either side for six
weeks. Bilateral hip replacements are not recommended for all patients.
Having both joints replaced at one time requires a commitment to work twice as hard
for a successful outcome, although bilateral joint arthroplasty has many benefits and is
worth the extra work in the initial recovery period.
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