A B C D E F G H I J K L M N O P R S T U V W

KNEE SURGERY FOR ARTHRITIS - TIBIAL OSTEOTOMY

Why is Knee Surgery for Arthritis performed ?

Tibial osteotomy is carried out to treat painful osteoarthritis of the knee. It is used only to treat patients with bow legs. In this case the arthritis is mainly in the inside compartment of the joint. The operation is reserved for younger patients, and for those who are not suitable for total knee replacement. Occasionally following a fracture of the tibia, the bone may heal in an unsatisfactory position. Tibial osteotomy may then be required to restore normal alignment. When this operation is to be performed for arthritis, the knee must at least bend to a right angle.

Preparations needed for Knee Surgery for Arthritis

The time in hospital will vary between 5 and 10 days. You will usually be able to return to a sedentary job at about 8 weeks. Manual work or jobs involving a lot of walking will require about 3 months off work.

What Happens during Knee Surgery for Arthritis

In the normal lower limb, weight is transmitted from the hip to the foot, equally through the inner and the outer part of the knee joint. When there is a bow leg deformity, the force is carried mainly through the inner part (compartment) of the knee. This increases pain and causes further wear and tear changes in this inner compartment of the knee. In tibial osteotomy, a wedge of bone is removed to realign the leg to produce a more knock-knee position. The operation is usually carried out under general anaesthetic but also can be done under a spinal or epidural anaesthetic. After the incision is made, the soft tissues are cleared from the bone and a wedge of bone is then removed. The base of the wedge faces outwards. The size of the wedge is calculated from standing x-rays taken before the operation. Enough bone is removed to over-correct the deformity of the leg by a small amount. This ensures that the line of weight transmission is moved to the outer compartment. The cut surfaces of the bone are held together with two staples, or a plate and screws. Occasionally other devices may be used, particularly if tibial osteotomy is being performed to correct alignment after a fracture. Finally, a small plastic suction drain is left in the wound and brought out through the skin. This is connected to a bottle and any blood that collects in the wound after the operation is sucked out. The leg is then usually supported in a plaster of Paris cast or a splint.

Possible Complications during Knee Surgery for Arthritis

General complications can occur and depend on your general fitness. Thrombosis of the leg veins is quite common, but a blood clot travelling to the lungs (pulmonary embolism) is uncommon. Complications can occur during the operation itself. Fracture from the osteotomy into the joint and injury to nerves or blood vessels happen rarely. In the first 24 48 hours after surgery there may be bleeding and swelling into the leg. This causes pain and may produce weakness of the foot. Re-operation may be required if release of the plaster cast alone does not relieve these symptoms. This complication is rare if drains are used. Infection of the bone or wound is also rare, since antibiotics are routinely given immediately before and after operation. The bone may fail to join up at the osteotomy site. This is usually obvious at 4 to 6 weeks after operation when the plaster cast is removed. A further period in plaster or later re-operation is sometimes necessary. As long as there was a good range of movement in the joint before surgery, stiffness is uncommon. Stiffness may, however, occur after some of the complications mentioned above.

After Knee Surgery for Arthritis

After surgery, pain should be easily controlled by injections or tablets. A drip is usually inserted into an arm vein during surgery but blood transfusion is rarely needed. The wound drain is removed after 24 to 48 hours. A physiotherapist will supervise muscle exercises from the first day after surgery. It is important to regain the ability to lift the leg up as soon as possible. Once this can be done, your walking improves rapidly. Partial weight bearing with the aid of crutches is usually permitted. Discharge home is allowed once stairs can be managed safely. The plaster may be changed and the stitches removed after 2 weeks. The cast is split at between 4 and 6 weeks and an x-ray taken. If this shows that the bone is joining satisfactorily, knee movement is begun. The back half of the plaster cast may be kept for the first week or two to provide support when walking. Continued physiotherapy is necessary to build up muscle strength and increase knee movement. Full weight bearing is allowed once the bone has healed. There is always some swelling around the knee after surgery. This gradually decreases over a few months. There may also be some swelling of the foot. This should go down if the leg is kept elevated when sitting. Once sitting and travelling is comfortable, sedentary work can be resumed. Manual work and sport cannot begin until muscles are strong and the range of movement adequate. This usually takes 3 months. Driving is safe once you are able to manage an emergency stop. Driving can start earlier after surgery on the left leg if a car with automatic transmission is available. This operation is not a cure for arthritis, but may postpone the need for total knee replacement for some years.

If Knee Surgery for Arthritis is not performed

The pain from osteoarthritis tends to vary with time. In general the degree of pain and stiffness in the knee will increase without surgery. This gradually makes walking and other activities more difficult. Ultimately, sleep may be disturbed by pain.