TOTAL HIP REPLACEMENT
ARTHRITIS OF THE HIP
The hip joint is lined by articular cartilage, a specialised lining which allows smooth pain free motion of the joint. Arthritis is a degeneration or wearing out of this lining which results in the bone ends rubbing on one another rather than the articular cartilage. The two most common forms are osteoarthritis and inflammatory arthritis.
WHAT CAUSES ARTHRITIS
Osteoarthritis is very common. The exact cause is unknown and can occur for no apparent reason other than general wear and tear. It may result from a number of conditions the most common of which are:
- Childhood hip disorders (e.g. a dysplastic hip)
- Avascular necrosis
- Certain diseases of bone and connective tissue
Inflammatory arthritis, the most common of which is rheumatoid arthritis, is an immune disorder whereby there is inflammation of the synovial lining of the joint which releases chemicals or enzymes into the joint resulting in damage to the lining (articular surface).
WHAT ARE THE SYMPTOMS?
- Pain which is usually located in the groin or buttock region
- Stiffness making it difficult to get to shoes and socks and get out of chairs
- Limitation of walking either due to pain or fatigue
- Grinding sensation in the hip
SEVERITY OF PAIN
- Is it mild, moderate or severe when walking?
- Is there any rest pain?
- Does the pain wake the patient at night?
- What type of analgesia do you need to control the pain?
ASSESS HOW THE PATIENT’S DISABILITY AFFECTS THEIR DAILY LIVING
- How far can the patient walk before the pain stops them?
- Can the patient negotiate stairs and do they need to use the banister?
- Can the patient put on their shoes and socks or cut their toenails?
- Can the patient get in and out of a car?
- Is the patient comfortable sitting in a chair for long periods of time?
HOW IS IT DIAGNOSED?
Osteoarthritis is diagnosed on history, physical examination and x-ray.
Physical examination will reveal pain on moving the joint and limitation of movement.
X-rays will reveal narrowing of the joint space and often deformity of the bones and new bone formation (osteophytes).
Blood tests are useful in inflammatory arthritis.
WHAT IS THE TREATMENT?
- Simple analgesia
- Anti-inflammatories supervised by local doctor
- Use of a walking stick in the opposite hand to take force off the hip
- Weight loss
- Maintenance of fitness and muscle tone
- Special medications for inflammatory arthritis
Operations for hip arthritis usually involve a hip replacement, but occasionally an osteotomy can be performed. This means cutting the bone and realigning it to take stress off a certain affected region.
The patient’s age has a large bearing on how aggressively one pursues more conservative lines of treatment. In general, people over the age of 65 are more likely to be offered joint replacement as a primary joint replacement should be expected to last for that patient’s lifetime.
A younger patient (i.e. < 65 years) is more at risk of developing loosening of that joint replacement and require revision surgery. Therefore, it is less likely to be an attractive option for both the surgeon and the patient.
TOTAL HIP REPLACEMENT
Total hip replacement is a “quality of life” operation. This operation should be offered to patients when their pain and disability are significant. This operation does not prolong a patient’s life but does make their remaining life more pleasant by decreasing their pain and disability.
Hip replacement surgery has evolved significantly over the last 40 years since first performed. There are improvements constantly being made. Modern-day hip replacements are extremely sophisticated and function well for many years.
Once the extent of the pain and disability of the patient is ascertained, it must also be established whether the patient is happy to put up with this level of pain and disability. If the patient is comfortable as they are, then non operative treatment will be pursued.
If the patient wants to pursue further options, then the operation may be offered to the patient. It is offered as a non-essential treatment for their hip disease. The patient must never have the operation forced on them or be told that it is essential.
In general, the progression of the disease does not make the operation more difficult and the worst affected patients tend to be much happier with their joint replacement.
Factors that influence me to offer the operation to the patient are:
- Age: <65 years
- Pain at rest
- Pain that wakes the patient at night
- Poor walking distance that does not allow the patient to walk to the corner shop or walk around their garden (200-300 metres)
- Pain unrelieved by analgesia or NSAID’s
The patient should never be hurried and should be made aware that it is his or her decision, not the decision of relatives or friends. The operation and its possible complications need to be fully understood.
WHAT TYPE OF JOINT?
The type of joint replacement used varies from surgeon to surgeon and may, in the future, be dictated by cost constraints. Discussion involves the type of hip and the bearing surface (what the ball and socket are made of). This can be high density polyethylene, metal or ceramic. All have advantages and disadvantages.
Uncemented joint replacements rely on a “press fit” and are manufactured with an irregular surface (e.g. titanium mesh) or a bioactive surface (e.g. hydroxy-apatite) to ensure ingrowth of bone into the prosthesis. The acetabulum may be augmented with screws. Cemented hip replacements are generally reserved for older patients with poorer bone quality.
POST OPERATIVE REHABILITATION
Most patients, after total hip replacement, stay in hospital 5-7 days. Patients usually start off walking on Day 1 or 2 on a frame and then progress to crutches and then a stick. They are usually on a stick by 3 – 4 weeks.
The patient uses a stick until they are able to ambulate without a limp. The stick is to aid the rehabilitation for their abductor muscles and to regain self confidence in walking.
It is rare, in total hip replacement, for the patient to require much physiotherapy after leaving hospital. Occasionally, if the patient has worrying stiffness or weakness, then physiotherapy may be instigated after discharge from hospital.
COMPLICATIONS AT HOME
The early post-operative complications are:
Early increase in pain, erythema around the wound, or significant swelling of the wound are indications to refer the patient straight back to the treating surgeon. Calf pain, swelling of the ankle or calf should be investigated urgently. Chest symptoms should be investigated for a pulmonary embolus and are best treated in a hospital environment. Sudden pain in the hip and shortening of the leg indicates dislocation which needs urgent x-ray and referral.
In the long term, the major complications are:
If the patient develops pain in their hip of a relatively quick onset this should be treated as suspected infection and investigated. It is very important to the patient’s primary treating physician that, if the patient has any operative or dental procedures, they are covered by suitable antibiotics. This is because bacteria seeding into the joint from any bacteraemia is possible.
Loosening can occur at any time and this is why the patient should be seen by their orthopaedic surgeon every year or two after the initial rehabilitation phase. X-rays may pick up changes which do not become symptomatic for a significant period of time.
Most patients return to clerical work at 6-8 weeks and manual work 10-12 weeks. It must be stressed to the patient before surgery that manual labour may wear the joint prematurely. Any heavy manual job will result in premature wear of the joint and loosening.
Obviously, pounding sports (e.g. jogging) are not good for joint replacement as they can wear the articulation. Recommended exercise alternatives include; regular walking, bushwalking, swimming, stationary bike riding, doubles tennis and skiing on groomed runs if the patient is already a good skier. Jogging and heavy weights, although possible, will wear the joint prematurely.
POST-OPERATIVE SEXUAL INTERCOURSE
Sexual intercourse is allowed when the patient is comfortable, but they have to be in charge of the positions used. Any significant discomfort should result in the patient abstaining. In general, sexual intercourse occurs at around 3 – 6 weeks post operatively.