The knee has the following structures:
Articular cartilage covers the bone ends and lets the knee move.
Menisci are two thick pads of tissue that form a rim inside the knee joint and stabilise the knee.
Ligaments hold the bones together, stabilising the joint.
The knee joint functions like a hinge at the junction of two bones, the femur (thigh bone) and tibia (shin bone).
Meniscus. The knee’s shock absorber.
Knees are a marvellous invention and without them you could not easily kick a ball, kneel down or climb into a car. The knee’s meniscus is tissue designed to absorb the shock of weight and the motion of the body. Too much stress can injure this shock absorber. However, meniscal tears can be effectively treated with surgery and rehabilitation which means you can usually return to an active lifestyle
A meniscal tear is commonly the result of a twist – a typical injury for someone like a netballer – or from repeated squatting. These tears create uneven surfaces that irritate the joint and may cause pain, swelling and a catching sensation. They often require surgery since they may not heal on their own. If not corrected, a meniscal tear can lead to more serious problems such as arthritis.
A meniscal tear acts like dirt in the ball bearings of a machine. The longer the torn tissue is there the more irritation it causes and an early evaluation by an orthopaedic surgeon means earlier treatment and less damage to the joint. Meniscal surgery can repair or remove torn uneven cartilage and rehabilitation with a physiotherapist ensures the best chance of a rapid recovery.
Arthritis means an inflammation of a joint causing pain, swelling, stiffness, instability and often deformity. Severe arthritis interferes with activities and limits lifestyle.
What causes Arthritis in the Knee?
Osteoarthritis or Degenerative Joint Disease is the most common type of arthritis. Osteoarthritis is also known as “wear and tear arthritis”, since the cartilage wears out. When cartilage wears away, bone rubs on bone causing severe pain and disability. The most frequent reason for osteoarthritis is genetic, since the durability of each individual’s cartilage is based on genetics. If your parents have arthritis you may also get it.
Trauma can also lead to osteoarthritis. A heavy fall or blow to the knee can injure the joint. If the injury does not heal properly, extra force may be placed on the joint, which over time can cause the cartilage to wear away.
When the articular cartilage wears away and is damaged it will become irregular, fissured and fall off revealing the bone. The damage is classified as mild or Grade III when it is irregular or fissured. The damage is classified as severe or Grade IV when the bone is revealed.
The articular cartilage can be damaged or wear away. If this happens the underlying bones rub together, producing the pain and inflammation typical of arthritis.
The Reason for an Arthroscopy
Arthroscopic surgery is used to correct mechanical problems within the knee joint. Unfortunately once the structures in the joint have become damaged failure to correct the damage will result in further deterioration of the knee.
Surgery will not be able to reverse the damage which has already occurred. It can only create the environment for the knee to cure itself. In the majority of cases recovery will be dictated by the degree of damage and how well you can rehabilitate the knee.
Arthroscopy is used to look inside the knee joint without disrupting the surrounding structures. The surgeon is able to confirm the nature of the injury and remove or repair the damaged part whilst causing little disruption to the knee joint.
If osteoarthritis is causing the problem, an arthroscopy will not be of any benefit.
The Arthroscopic Procedure
The arthroscope is a pencil thin tube containing light fibres and a means of transmitting a picture from inside the knee to a video camera. In addition, the knee joint is filled with fluid to allow the arthroscope to be moved through the joint. The arthroscope is inserted through a small incision, less than 1 cm long, just below and on the outside of the knee cap. At least one other incision is made on the inside of the knee cap. Sometimes more than two incisions need to be made to insert the small instruments to carry out the actual surgical procedure.
What is involved in having arthroscopic surgery?
In most cases arthroscopic surgery requires hospitalisation for one day only. The surgery causes very little disturbance to the knee joint and consequently the post-operative discomfort is decreased compared to open surgery. The degree of pain varies with each individual and is not just related to the procedure or the amount of work carried out. After surgery you should start your exercises and apply ice when necessary.
Before you give permission for the operation make sure you understand what is involved and what the risks are – and possible complications.
Q. What sort of anaesthetic is used?
A. General anaesthetic.
Q. How long will I need to stay in hospital after the operation?
A. For about four hours after the operation is completed.
Q. Will I have pain?
A. You will have some pain but the degree will vary in different patients. Do not be frightened to take pain killers.
Q. Can I drive home?
A. You are not allowed to drive or make a legal decision for 24 hours.
Q. Are there risks in the operation?
A. They are the same risks as for any surgical procedure. They are very rare but do occur and include infection and DVT (blood clot in the leg).
Q. What do I do if I am taking medication.
A. Bring them to the hospital, tell the nurse and the anaesthetist.
Q. What do I do if I am possibly suffering from a contagious disease?
A. It is very important to you and all the people involved in your care that you tell them.
Your role post operatively
Arthroscopic surgery on your knee is the first step in helping it overcome mechanical problems but it is up to you to look after your knee properly postoperatively to make a full recovery.
You need to take time to care for your knee by resting, elevation, icing and simple knee exercises.
You must remember that every injury is different and that there are many factors due to age, occupation, fitness levels that can affect the recovery of your knee. Do not compare your recovery with other people – your injury is unique.
Carry out 240 straight leg raises per day, 20 at a time with a rest in between. Sitting on the end of a bed or chair, lift your foot up into the air, count to 5, then slowly lower your leg. When resting have your leg straight and not in a bent position.
You may require pain relief over the first 48 hours. Take two tablets every four hours as necessary.
The most common cause of pain is swelling. Elevate and apply ice to your knee for two days postoperatively, two to ten times a day. Apply ice for 20 minutes on and off to your knee (make sure you wrap the bag of ice in a towel to protect your skin) until swelling subsides.
You must keep the leg dry for ten days, after which time you may have a wash.
Make an appointment with Dr Wood to have your surgery reviewed and the wound checked, preferably ten to fourteen days post-operatively.
A week before surgery, make an appointment to see a physiotherapist as soon after surgery as possible.
Dr Wood is mostly using clear absorbable sutures.