The hip joint is a ball and socket joint, which connects the top of the thigh bone (the femur) to the pelvic bone (the acetabulum). It is held together by a joint capsule, ligaments, muscles and tendons.The ball and socket are covered with a thin lining, approximately 3mm deep, called ‚”Articular cartilage”. It is these two surfaces that come into contact against each other when the hip joint moves. This movement, in a normal hip joint, is virtually friction-free. However, when the joint becomes diseased, damaged or worn out, this cartilage cushion wears away and allows the bone surface underneath the cartilage to start rubbing against the bone surface of the other side of the joint. This leads to pain, stiffness, limping and weakness.
Prior to surgery you will be seen by myself and my anaesthetist and the procedure and the anaesthetic options will be discussed thoroughly with you. On the day of surgery, it is important that you do not eat and drink anything after 2.00am, which ensures that your stomach is empty and significantly reduces any risk of aspirating stomach contents during the procedure. I will mark your limb and obtain your signature for consent and then you will proceed down to the operating theatre. Most patients have a regional (spinal or epidural or local nerve block) combined with sedation or a general anaesthesia. You are free to discuss the pros and cons of each of these with my anaesthetist and almost everyone’s request is heeded (except those that want to sit up and watch!). The surgery will go ahead only when you are completely anaesthetized, so that you will not feel anything. It takes place in a specialized, modern theatre with thevery latest in ultra-clean air filtration systems (This reduces the risk of airborne contamination which can cause infection).
The surgery will take approximately 60-90 minutes and then you will be transferred to the Recovery Room for a further 60-90 minutes before proceeding back to the ward. During this time you are closely observed by the medical and nursing staff and made as comfortable as possible. Various physiological parameters are closely monitored, (such as blood pressure and pulse, oxygen saturation, intravenous fluid intake and output). Once back on the ward, the ward staff will attend to you and provide you with an extremely high level of nursing care. This is both for your comfort and for your safety. You will be given as much pain relief as you require to make your postoperative stay as pain-free as possible.
Different people recover at different rates. The final success of a hip replacement is many years of pain-free hip function. To achieve this goal, it is necessary to do some rehabilitation and generally look after yourself.
- It is important to walk every day, as this increases muscle, ligament and tendon strength. It will rebuild your muscles that will have become wasted as a result of the painful arthritis, and it will help to increase the density of your bone, preventing osteoporosis.
- It is important to take good care of your skin, both on the operated site and around the rest of the body. Your skin is a protective barrier against infection and any breach in this barrier could potentially allow infection into the blood supply, which may result in seeding of the infection in the artificial hip joint. This in itself is likely to require a significant amount of further treatment (both surgery and medical treatment) to cure the infection.
- Dental hygiene should be a high priority and any abscesses should be dealt with prior to hip replacement surgery. Following hip replacement surgery, it is important that abscesses are treated promptly and comprehensively with antibiotics to stop infection travelling in the blood supply around to the hip joint.
- Most hip joints are designed to give you almost normal hip movement. However this is not a completely normal movement. There is one particular movement which should not be attempted as this may result in a dislocation (the ball coming out of the socket – extremely painful!). This position, WHICH SHOULD BE AVOIDED, is with the knee bent up and in, and the foot bent up and out. I will run over the safe and the unsafe positions with you both before and after surgery and if you ever have any concerns, just remember both knees and ankles together is safe.
- Deep vein thrombosis/pulmonary embolism (DVT/PE) – blood clots in the veins in the legs or lungs
- Neurovascular injury – damage to nerves or blood vessels
- Infection, which can be superficial in the wound or deep in the new joint
- Dislocation – where the ball comes out of the socket
- Fracture – where the bone breaks around the hip joint
- Leg length discrepancy – where one leg is longer than the other
- Trochanteric bursitis – inflammation and pain over the bony part of the femur, just under the wound
- Myocardial infarct (heart attack) or CVA (stroke).
- Stiffness due to heterotrophic ossification (exuberant bone growth around the hip joint).
- Leg swelling and stiffness – this always occurs to a greater or lesser extent and resolves over 4-6 weeks
- Haematoma (an accumulation of blood around the surgical site that may require drainage.
- Loss of blood during surgery that may require a blood transfusion.
- Numbness – pain or itchiness around the scar.
All patients who have had a hip replacement will be seen approximately 6-8 weeks after surgery in an outpatient clinic. Further questions can be answered and it is about this time that I tend to suggest an activity-based rehabilitation programme to increase peoples strength, fitness and stamina.
The recovery up to the 6-week mark is generally the same for most people and I would advise avoiding the gym or swimming for the majority of this time.
The decision for surgery should be made by the patient in conjunction with the orthopaedic surgeon. In the vast majority of cases, the decision should be made by the patient, only rarely should an orthopaedic surgeon persuade a patient to consider a hip replacement sooner rather than later (e.g. concerns that the ball or the socket are wearing out, which would mean that the surgical technique becomes significantly more difficult and this may result in a less successful outcome). Most patients deciding on surgery will be having pain on a daily basis. There is often a constant underlying baseline ache, which is made worse by certain movements, activities or positions (e.g. going for a walk, getting in and out of a car or trying to put on shoes and socks).
In the first instance, simple pain relief such as Panadol may help with these symptoms. Often patients who are able to take anti-inflammatory medication will find good relief of their symptoms and sometimes stronger painkillers, which are prescribed by a medical professional, will be required as the hip pain worsens. Quite often, the pain will get worse at night and may even keep people awake, or wake people up from sleep.Physiotherapy and various activities and movements, such as swimming, may also be beneficial to the joint and may help relieve some of the pain and stiffness. The stiffness typically makes it difficult to sit in a low chair, put on shoes and socks and paint or clip toenails / wash between the toes. Whilst painkillers and anti-inflammatory medication, exercise modification and walking aids, e.g. walking stick may help the symptoms, they will not cure the diseased hip.
The hip will slowly deteriorate and it is at this point when non-operative measures have been tried and exhausted, most orthopaedic surgeons would recommend the consideration of joint replacement.
I would suggest that most patients have approximately 6 weeks off work, if still in employment, for very similar reasons to those given above for driving. It is important to rehabilitate and do the exercises that will be shown to you in hospital and also it is my experience that after this form of surgery, most patients are really quite tired for 3-4 weeks and require more sleep and rest than usual. Obviously, each individual job should be taken into account and I can discuss this further with you when we meet up.
We do not know exactly how long an individual hip will last. It will vary, depending on the type of hip replacement (prosthesis), the surgical technique, the activity level of the patient, other patient factors (e.g. co-morbidities, obesity) and a little bit of luck.
When a hip replacement wears out, it is still possible in almost every case to revise the hip and put in a new hip joint. However, the complications and the risks associated with revision surgery are slightly higher than with surgery first time around. The long-term results are also slightly less predictable.
There are a number of causes for hip problems. The most common is osteoarthritis (wear and tear, generally related to age). Rheumatoid arthritis is a condition whereby the lining of the joint becomes extremely inflamed and starts to destroy the healthy articular cartilage. Some times the joint does not develop normally from birth (developmental dysplasia of the hip) and sometimes the blood supply to various parts of the femoral head is interrupted and this bone slowly dies (avascular necrosis). Severe trauma, such as an intra articular fracture or dislocation, can produce post-traumatic arthritis and fractures in the neck of the femur, which occur in people with osteoporosis, may also require hip replacement surgery. A hip replacement is also called a Hip arthroplasty (the technical term). Its aim is to alleviate pain and provide a near-normal range of movement. During the procedure the head and neck of the femur are removed and the inside few millimeters of cartilage and bone in the acetabulum are also removed and an artificial joint is inserted.
In some cases it may be best to replace both hip joints during the same operation. This tends to be in some patients who are confined to a wheelchair or who suffer from extreme stiffness or pain and think that rehabilitation after one may be made extremely difficult because of arthritis in the other hip. Recovery and rehabilitation tend to be a little bit more difficult and uncomfortable in the first few weeks after surgery, but there is the advantage of less total time off work for recovery.
Southern Cross Hospital
232 Wairau Rd
The Doctors Fred Thomas (Fred Thomas Health, Takapuna)
2 Fred Thomas Drive
Silverdale Medical Centre
4 Silverdale Street
Kawau Bay Health Centre
Warkworth Cnr Percy & Anwick Streets
Westgate Medical Centre
Westgate Westgate Shopping Centre