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ARTHRITIS IN THE KNEE
ANATOMY
The knee is a joint articulation formed between the top of the shin bone (tibia) and the bottom of the thigh bone (femur). It has the appearance of being a simple construction, but, perhaps not surprisingly, it’s much more complex.
Like all large joints in the body, the joint surfaces of the knee are covered in what is known as hyaline cartilage. This cartilage protects the knee against stress and absorbs shock.
As we age, this “cushioning” cartilage can wear away naturally. Also, damage can occur prematurely due to infection or trauma. When this occurs naturally, as part of the ageing process, it is known as osteoarthritis.
As this cushioning cartilage thins, the knee has less protection against shock and the bone ends can become “injured” by day-to-day activities such as walking. The underlying bone can become inflamed, which in turn can produce aching pain.
The symptoms of osteoarthritis include:
• aching pain within/around the knee
• occasional swelling
• some stiffness after activity
This, in turn, can then result in:
- a diminished tolerance to exercise e.g. running or simple walking
- decreased mobility
- reduced independence
- need for medication
When the level of pain becomes intrusive and disruptive to daily life, this is the point at which all treatment options should be considered.
DIAGNOSING OSTEOARTHRITIS OF THE KNEE
Diagnosis involves listening to the patient’s history during the consultation, examination of the patient and the use of specialised tests.
Plain weight-bearing radiographs (x-rays) of the knee are taken to see how much cartilage has been lost. They will also show if there is any deformity in the knee or extra bone formation (osteophytes). These are caused by bone rubbing on bone due to the loss of cartilage.
TREATMENT OPTIONS
It is preferable that osteoarthritis is treated conservatively (without surgery) for as long as possible. However, the need for replacement of the joint may ultimately become inevitable, due to deterioration in the condition of the joint leading to increased disability and pain.
CONSERVATIVE TREATMENT
Conservative (non-invasive) treatment of knee osteoarthritis involves a combined approach:
1. Physiotherapy/muscle strengthening
2. Pain management
3. Weight loss
I believe strongly that physiotherapists have a significant role in keeping patients away from the need for surgical intervention for as long as possible.
The pain from arthritis can be helped significantly, often for many years, by the intermittent, rather than regular, use of non-steroidal anti-inflammatory (NSAI) medication.
On occasions, some patients will be considered suitable for a series of hyaluronic acid injections into the knee as a part of the treatment referred to as viscosupplementation. These injections help to lubricate the degenerating joint surface and can be very effective in a small majority of ‘early’ cases.
Similarly, there is a role for the use of injected steroid into the knee when/if acutely inflamed but is usually considered in rare episodes of extreme discomfort. Weight loss, if appropriate, will reduce stress on the knee.
Hopefully, with conservative management, patients can avoid the need for surgery for many years after the onset of arthritis.
ARTHRITIS AND KNEE REPLACEMENT SURGERY
Opting for Surgery
Knee replacement surgery, like all joint replacement surgery, is a very major operation and requires careful consideration and discussion before proceeding.
If, however, the patient and surgeon have come to the decision that there is little alternative, replacement surgery can offer immense symptomatic relief to the patient.
Knee replacement surgery can be divided into total knee replacement surgery or unicompartment replacement surgery. In both cases, the operation is carried out under general or regional anaesthesia (spinal) and lasts approximately one to one and a half hours.
Total knee replacement surgery involves the replacement of all aspects of the joint (including the kneecap) with an artificial bearing surface.
Surgery restores the normal alignment of the joint, as well as the smooth articulating surface that has been damaged by osteoarthritis.
This surgery also restores the normal alignment of the soft tissues (ligaments/muscles) around the bone so that the knee continues to work in as near to normal a fashion as it did before the arthritic process started.
Understanding the risks
As with all operations, it is very important that you fully understand the ‘pros’ and ‘cons’ before electing to proceed with surgery. Whilst the benefits are clear, time must be given to discuss ‘what can go wrong’.
The main risks of knee replacement include:
* Deep Vein Thrombosis, leading to pulmonary embolism (blood clot to lung)
* Nerve or blood vessel damage during surgery
*Chronically painful knee replacement (of unknown cause)
Whilst all of these complications are extremely rare, they can occur.
Patients usually stay in hospital for up to one week. During this time you will have daily physiotherapy.
Patients are ready to leave hospital when they can:
* Bend the knee to a right angle
* Manage stairs independently
* Walk independently with two sticks
After surgery
Sutures/clips in the skin will be removed at two weeks by your GP or at the hospital if preferred.
I review most patients after six weeks to check on their progress.
My main concern is to ensure that the wound is healing well and that the swelling is beginning to reduce. However, you should expect the knee to be swollen for some months and therefore your flexibility will be quite markedly restricted by this swelling.
Only when the swelling has diminished and the knee is moving well can you start to build up the muscle that will have wasted away in the preceding months. Physiotherapy is a vital part of the recovery process and needs to be arranged in advance of the operation.
Recovering from a total knee replacement operation takes time; sometimes it takes as long as a year for the knee to feel comfortable again.
Interrupted sleep, unfortunately, is normal in the first three months after such major surgery and you should be prepared for this.
UNICOMPARTMENTAL REPLACEMENT SURGERY
This form of knee replacement surgery is given if you have osteoarthritis affecting just one compartment of their knee – the inner (medial) or outer (lateral) joint surface, or, very rarely, the kneecap.
It is less invasive than total knee replacement surgery. This means that more of the original knee is preserved which has the benefit of retaining a more natural movement.
Anyone who presents with arthritis is considered for this less invasive procedure, but, unfortunately, only a minority of patients are actually found to be suitable.
The deciding factors include your age and the exact distribution of arthritis. The best way to assess the situation is by arthroscopy, either at the time of knee replacement surgery, or beforehand.
I favour the Oxford unicompartmental replacement http://www.biomet.co.uk/home-uk
Frequently Asked Questions
How long will I be in hospital for?
Seven nights.
When can I drive again?
After 6 weeks.
When and who will take my stitches out?
You can either come up to the Knee Unit 2 weeks after surgery, or if it is more convenient you can see the nurse at your local GP practice.
Will I require physiotherapy following my op?
You will need to see a physiotherapist about once a week for the first few weeks. If you don’t have a physiotherapist, please call Mr Sweetnam’s secretary who will recommend one in your area.
When do I see Mr Sweetnam again?
Six weeks post op.
When can I return to work?
You can go back to work 6 weeks following surgery.
Seek solutions where surgery is the last resort