Total Knee Replacement Overview
Total knee replacement is performed for severe, debilitating knee arthritis, to restore pain free mobility and function to patients usually above the age of 55 to 60 years. More properly considered a resurfacing procedure, the arthritic surfaces of the knee are replaced with anatomic metal and durable plastic components through a 6 inch incision at the front of the knee while under a spinal anaesthetic. Walking commences immediately following surgery, and the patient is usually discharged from hospital 2 to 4 days later with a walker or crutches. The patient is followed with physiotherapy until walking comfortably and independently, usually by 1 to 2 months.
Total Knee Replacement Details
Knee arthritis can be a debilitating condition, causing pain, stiffness, and decreased mobility. Non-operative treatment includes maintaining fitness and a normal weight, bracing, medication, injections, and sometimes a walking aid. If these are ineffective, total knee replacement surgery may be the best option to effectively treat the problem. This procedure safely and predictably provides pain relief and increased mobility, and is one of the most successful medical procedures to improve quality of life. It is considered major surgery, and requires significant effort to rehabilitate the leg after surgery.
If non-surgical measures have failed, and there is bone on bone arthritis on X-ray, total knee replacement may be considered. An MRI is not needed. Suitability for surgery includes a stable medical status, which may need to be further assessed to determine safety of the procedure. As well, it is important that the patient be willing and able to participate in a vigorous rehabilitation process. Occasionally additional knee X-rays are needed for surgical planning. Both knees can sometimes be replaced under the same anaesthetic in appropriate patients. Details of the surgery, including risks and benefits, will be discussed in the office. Forms will be filled and lab work will be completed. Sometimes an anaesthetist referral is needed.
The wait time for knee replacement surgery may be a year or more, although significant efforts are being made to shorten this wait time. It is important that the patient attend the Prehab Clinic at the Brandon Regional Health Centre, which is scheduled prior to the surgery date. Here it is ensured that all medical issues are dealt with, lab work is in order, necessary home supports are in place, and preoperative exercises are initiated. This will help optimize outcome and patient satisfaction.
The procedure takes place on the day of admission usually under spinal anaesthesia, and lasts less than an hour. Postoperative pain is controlled with local freezing, a cooling cuff, and medication. X-rays are taken, and full weight bearing commences immediately. Patients will begin physiotherapy the day after surgery, and can usually go home within 2 to 4 days, once pain is controlled and they are mobilizing well with a walker or crutches. If there is extended delay in mobilization after surgery, sometimes due to advanced age, a transfer to a rehabilitation facility or the patient’s home hospital may arranged, depending on availability.
Walking aids are used for several weeks, and mobilization is encouraged. Blood thinners are prescribed to reduce the risk of blood clots. An occupational therapy assessment will have addressed appropriate home supports or modifications. Daily exercises are very important to the overall success of a knee replacement. Followups with the surgeon and physiotherapist are arranged.
Any operation has potential complications, but these are rare.They can include anaesthetic complications, worsening of pre-existing medical problems, prolonged knee stiffness, infection, blood clots in the legs or lungs, implant failure, or bone fracture. In approximately 5 to 10% of cases later revision surgery is required to address complications or significant deterioration of the knee replacement, especially if initially performed in younger patients. Revision replacements may not be quite as effective as the primary replacement.
Each patient recovers at their own rate. Patients can usually drive after 2 to 4 weeks, garden after 4 to 6 weeks, and golf after 8 to 10 weeks. It is expected that the patient will be able to resume the activity level they enjoyed before being limited by the knee arthritis, assuming there are not additional health or mobility issues. The implant is designed for activities such as brisk walking, and patients can conceivably return to recreational involvement in golf, tennis, cycling, swimming, skating and cross-country skiing, for example. Running, jumping and other impact activities are discouraged.
Improvements in comfort and function can continue for up to a year following a knee replacement. There may be some residual symptoms, and the knee can remain warm for a number of months. There may be some initial sleep disturbance following surgery. The implant is designed to achieve about 120 degrees of flexion, but may be less in some patients, especially if they have considerable stiffness before surgery. Kneeling is allowed, but some patients find this uncomfortable. There may be some numbness around the incision or clicking noises in the knee, but this is normal. Patients are typically followed up for 6 to 12 months after surgery.