The
hip
The hip is one of the ‘bread-and-butter’ joints in orthopedics,
and provides a very substantial proportion of the total workload of an
orthopaedic surgeon. In infants the problem of congenital dislocation of the hip
is important because it is treatable if diagnosed early. The hip is also
susceptible to septic arthritis, especially in the newborn (Table
23.1). In
children, Perthes’ disease, an avascular necrosis of the hip, poses a major
therapeutic challenge. In the young adolescent slipped upper femoral epiphysis
needs early diagnosis if problems are to be avoided for the rest of the
child’s life. In the young adult hip dysplasia may start to cause problems
which will eventually go on to arthritis of the hip and which will pose severe
problems for future hip replacement. In the elderly primary osteoarthritis of
the hip is so common that, in Britain alone, over 50 000 total hip replacements
are performed each year. Osteoporosis and problems of balance in the elderly
also brings about a rapid rise in the incidence of fractured neck of femur.
This, too, requires surgical treatment, providing the majority of major
operations needed in trauma services.
Principles
of history and examination of the hip
Pain
— localisation and radiation
Patients find pain originating from the hip very difficult to localise.
Children presenting at the clinic with a limp, a painful knee and a normal knee
X-ray (King’s triad) will usually be found to have a problem in the hip not
the knee. Similar problems occur in the elderly, who may complain of pain down
the front of the thigh and into the knee, when the diagnosis is osteoarthritis
of the hip. However, pain originating from the back can radiate down into the
buttocks
Disability
— activities of daily living
Patients with a stiff hip complain primarily of difficulty getting in
and out of the bath and low chairs, as well as problems with getting socks and
shoes on. The combination of pain and stiffness from osteoarthritis may also
limit their walking distance.
Deformity
Problems in the hip lead to flexion and adduction of the joint. This
leads to a tilt of the pelvis and a leg which appears to be shortened. The
patient will therefore stoop and limp because of pain, weakness and deformity.
Osteoarthritis
Most osteoarthritis is called primary because there is no known
preceding cause. There is a genetic effect, but the reason why some joints
apparently last the lifetime of a patient while others disintegrate is not well
understood. Secondary arthritis can occur following congenital subluxation of
the hip, Perthes’ disease secondary to trauma or an inflammatory arthritis
such as rheumatoid (see Table 23.2).
Prevention
There is some evidence that young people involved in high-intensity
sport and/or heavy-duty work are more susceptible to osteoarthritis later in
life, but the affect is surprisingly small. Secondary osteoarthritis may be
prevented by minimissng the damage to the joints caused by the primary
disease.
In trauma articular fractures should be anatomically reduced. In inflammatory
joint disease every effort should be made to reduce the level of inflammation.
Treatment
In the early stages osteoarthritis affects the patient in all three main
areas of orthopaedic endeavour. It causes pain, disability and some deformity.
It may also cause high levels of anxiety in the patient who may be worried that
the condition is going to rapidly deteriorate and spread to other joints,
destroying their quality of life. Many patients are resistant to taking tablets
of any sort. There is no evidence that pain killers or anti-inflammatory drugs
do anything but relieve the symptoms, and they may even accelerate the
pathological changes. The key issue at this early stage for the quality of life
of the patient is to maintain mobility and to avoid deformity. Physiotherapy
should be used to show the patient how to keep joints mobile and muscles in good
condition. The psychological benefit of this is also almost certainly
important.
More
severe osteoarthritis
As the condition becomes more severe regular analgesia may be needed.
The use of centrally acting pain killers, such as paracetamol, combined with
nonsteroidal anti-inflammatory drugs appears to provide a synergistic effect in
terms of pain relief, but care must be taken to avoid gastric irritation and
ulceration.
Indications
for joint replacement
Indications for joint replacement are:
• pain;
• stiffness;
• loss of independence.
In
the elderly, loss of independence through disability is a crucial issue. A
painful stiff and deformed hip may prevent a person from sleeping, from doing up
their shoes, from going out to do their shopping and even from using a car or a
bus. This combined with chronic pain may convert a cheerful outgoing involved
member of society into a depressed and isolated individual reliant on others for
their needs. The cost to the individual and to society is out of all proportion
to the pathological effect of the disease itself. A total hip replacement
reverses this cycle. Combined with the judicious use of physiotherapy and
occupational therapy, this gives the patient the confidence to return to an
active independent life. In the patient over 65 years with a life expectancy of
around 20 years, total hip replacement is the treatment of choice for
osteoarthritis. In the younger patient the likelihood is that the joint
replacement will not last the lifetime of the patient. They can be replaced (a
revision operation) but this is technically difficult and the next operation
does not last as long as the first. In younger patients secondary osteoarthritis
is more common than primary and in these patients fitting the hip replacement
securely in the abnormal anatomy may be much more difficult than in a simple
elderly patient. The patient may also put greater loads on the hip. If a patient
has a normal life expectancy, the younger the patient the more carefully
alternatives to total hip replacement must be considered.
Rheumatoid
arthritis
Total hip replacement in patients with rheumatoid arthritis is a
successful operation. Perhaps this is because the patient has put very little
load on the hip, but the relief of pain and the increase in mobility can have a
dramatic effect on the quality of life of the patient.