Unicompartmental (Partial) Knee Replacement
Unicompartmental knee replacement (UKR) is an option for a small percentage of patients with osteoarthritis of the knee. The arthritis should be confined to only one compartment of the knee joint. In UKR only the damaged compartment is replaced with metal and plastic. The healthy cartilage and bone in the rest of the knee is left alone.
Advantages of UKR (compared to total knee replacement)
- Quicker recovery
- Less pain (because of smaller incision and less soft tissue damage)
- Less blood loss
- Possibly more movements of the knee
- Knee feels more like ’normal’ knee (because of retainment of cruciate ligaments)
Disadvantages of UKR
- Less precitable outcome (compared to TKR)
- Potential for future surgery (because of progression of arthritis
UKR is not a suitable operation in the following cases
- Obese patients
- Patients with inflammatory arthritis (like rheumatoid arthritis)
- Patients with deficient/torn cruciate ligaments
- Very stiff or bowed knee
- Arthritis in more then one compartment (though patients with patella femoral arthritis with no symptoms may be suitable candidate for medial UKR)
Total Knee Replacement
TKR is a good option for patients suffering with widespread arthritis in the knee. It gives excellent pain relief and thereby improves the mobility and quality of life.
There are no absolute age or weight restrictions for total knee replacement surgery.
Recommendations for surgery are based on a patient's pain and disability, not age. Most patients who undergo total knee replacement are age 50 to 80, but orthopaedic surgeons evaluate patients individually. Total knee replacements have been performed successfully at all ages, from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis.
Before the surgery the patient will undergo a complete medical evaluation (either by a physician or a pre-operative assessment nurse), blood and urine tests and an electrocardiogram. Other tests may be required depending on the health of the patient.
You may be admitted a day before or on the day of the surgery. The anaesthetist will discuss about the type of the anaesthesia suitable for you (with your input).
The operation itself takes only one to two hours and you will in the recovery room for few hours.
You may be in the hospital for 3-7 days and during this time the doctors and the nursing staff will make sure that your pain is well under control. The physiotherapist will help in mobilising the knee the next day and will teach you a set of exercises and help with activities like stairs. It is important to do these exercises on a regular basis as these help to strengthen the muscles, restore knee movement as well as prevent blood clots in the leg. You may be discharged with a set of crutches or frame (depending on your home situation).
Once home it is important to continue with the exercises. The sutures or clip will be removed in 10 – 14 days by the doctor or a nurse. Over the next 4 – 6 weeks you will find a gradual improvement in the knee replacement and hopefully mobilise without any walking stick or crutches. The pain should have settled down and may require only simple pain killers. By 6 weeks you should be able to achieve around 90 degrees of flexion (bend). If not you may require a manipulation under anaesthesia. Also during this time look out for signs of clot in the leg (calf pain, swelling and tenderness) and infection in the knee (increase pain, swelling, redness, discharge from knee wound and fever). You should contact your doctor urgently if you have these complications.
You will see the benefit of the TKR over the next one to 2 years. The swelling in the leg can take upto 6 – 12 months to settle down. As with a natural knee, the replacement doesn’t last forever and can wear out or become loose. This could require a further procedure, a revision knee replacement. Currently, more than 90% of modern total knee replacements are still functioning well 15 years after the surgery. Following your orthopaedic surgeon's instructions after surgery and taking care to protect your knee replacement and your general health are important ways you can contribute to the final success of your surgery.