Selection of Indications for Total Knee Arthroplasty
The correct selection of surgical indications is the primary factor affecting clinical outcomes. Artificial total knee replacement is mainly used for severe joint pain, instability, deformity, and serious impairment of daily living activities, and the history of conservative treatment is ineffective or the effect is not significant. These include: 1) various inflammatory arthritis of the knee joint, such as rheumatoid arthritis, osteoarthritis, hemophilic arthritis, etc.; 2) a few traumatic arthritis; 3) osteoarthritis after failed high tibial osteotomy; 4) patellofemoral arthritis in a few elderly people; 5) resting infectious arthritis; 6) a few primary or secondary osteochondro-necrotic diseases, etc.
The main majority of cases are patients with severe osteoarthritis of the knee.
The purpose of surgery: (1) to relieve pain; (2) to improve function.
Patients proposed for total knee arthroplasty should have.
(1) radiographic evidence of joint damage.
(2) Persistent moderate to severe pain that has not been relieved by considerable non-surgical treatment.
(3) Clear clinical evidence of limited joint function and consequent impact on quality of life.
Age of TKR patients.
(1) In the past, TKR was considered most appropriate at 60-75 years of age.
(2) This age range is now being expanded. However, it should be noted that older patients often have more comorbid other systemic diseases; younger patients in turn can increase mechanical failure of the prosthesis due to high mobility
(3) In patients under 55 years of age, alternative treatments such as osteotomy and unicondylar replacement should be considered.
Contraindications to total knee replacement surgery
Not all patients with severe osteoarthritis are candidates for total knee replacement. Absolute contraindications include paralysis of the muscles surrounding the knee joint; those whose knee has been fused in a functional position for a long time without symptoms such as pain and deformity; those with any active infection of the systemic and local joints; and those with complications such as severe cardiovascular disease that cannot tolerate surgery; relative contraindications include young age, high postoperative activity, obesity, poor surgical tolerance, severe peripheral vascular disease and certain neurological impairments.
Outcomes of TKR.
(1) The perioperative mortality rate was 0.5%.
(2) In both short and long term, in 90% of patients, TKR provides rapid and effective pain relief, improves function, and enhances the patient’s quality of life; 85% of patients are satisfied with the surgical outcome.
(3) The reasons for the lack of significant surgical results are still unknown.
Prevention and treatment of complications of total knee arthroplasty
Common complications of total knee replacement include loosening of the artificial joint, dislocation of the artificial joint, wear and tear of the artificial joint, and other complications: vascular and nerve damage during the release of the posterior joint capsule; fracture of the patella and other fractures; infection, venous thrombosis; and joint instability. Among them, deep vein thrombosis of the lower limbs and surgical infection are the most common.
(1) Prevention of lower limb deep vein thrombosis, the incidence of deep vein thrombosis after total knee replacement is as high as 40% to 60%, so it is necessary to pay sufficient attention. Common preventive measures: preoperative and postoperative hemostatic drugs should not be used, intraoperative and postoperative bleeding can be supplemented in adequate amounts, but hemostatic drugs are prohibited (except in special cases). Postoperatively, the affected limb should be elevated and active exercises such as quadriceps, ankle flexion and extension rotation and passive functional exercises of the knee joint on the CPM machine should be performed within 24 hours. Since the patients were using pain pumps, there was no need to worry about the pain of the affected limb. Along with the application of salvia injection, low-molecular heparin calcium was started on the second postoperative day and applied continuously for 5 to 7 days. No deep vein thrombosis occurred in this group of patients.
(2) Prevention of infection, the incidence of total knee replacement infection is reported to be l-2% at present. According to the extent of involvement, the infection is divided into superficial infection (not involving within the joint capsule) and deep infection (involving within the joint capsule). According to the onset and course of the disease, it is divided into acute or early infection (within 2 weeks after surgery) and chronic or late infection (after 2 weeks after surgery). Infection prevention measures are as follows: preoperative skin cleansing and prophylactic preoperative application of antibiotics for 3 days to control potentially infected lesions. One more antibiotic should be applied before or during the skin cut, the air in the operating room should be sterilized (our hospital is a laminar flow operating room), the skin should be sterilized strictly according to the operation protocol before the operation, the operation should be finished with thorough rinsing, and the intra-articular and subcutaneous drainage should be unobstructed after the operation. The antibiotic we applied for this operation is ceftazidime injection 4-6g/day for 7-10 days. We also increase nutrition, improve the patient’s physical condition, enhance resistance, and prevent complications such as diabetes, respiratory and urinary tract infections.
How many years does an artificial knee joint last?
Artificial joints, like shoes, wear out when you walk. However, the strength and wear resistance of the artificial knee material has been tested hundreds of times through wear and tear, and can generally meet the needs of patients for 15 – 20 years or more. A successful artificial joint replacement allows you to live a pain-free life and meet your daily activities, and no other treatment can achieve the same results for a damaged knee. Of course, the longevity of the artificial joint is also dependent on many factors, such as the amount of exercise the patient performs, the choice of prosthesis, the surgeon’s surgical technique, and his or her condition. The orthopaedic community is currently working with engineers and material scientists, among others, to improve artificial joint materials, processes and surgical techniques. The future is bright for patients who choose joint replacement to improve their quality of life and want to be healthy and pain-free in their activities.
Whether to have a total knee replacement
This decision must be made in consultation with yourself, your family, and your orthopedic surgeon, and this step is often initiated by the orthopedic surgeon, after an initial evaluation.
Common reasons for having a total knee.
1. Severe knee pain that limits your daily activities such as walking, going up and down stairs, sitting in a chair or getting up from a chair. Sometimes you may find it painful to walk a few blocks and you may need the help of a walker or cane.
2. pain when you are resting during the day or at night.
3. Inflammation and edema in the knee that does not improve with rest or medication.
4. deformities occur in the knee, such as the knee becoming rotund or touching inward
5. The knee feels strong and hard, with difficulty in extension and flexion.
6. Ineffective with non-steroidal anti-inflammatory drugs, including aspirin and prilosec, which are effective in early arthritis and have different effects depending on the individual, and when the arthritis is severe, the efficacy of these drugs is not obvious.
7. poor response to the effects of painkillers, which can even cause complications.
8. Poor response to physical therapy, hormone injections and other surgical procedures.
Most patients are between 60 and 80 years of age, but doctors make different decisions depending on the individual. The recommendation for surgery depends mainly on the patient’s pain and lesions, not on age, and a successful total knee replacement may be achieved in a young person such as 16 years old or in an older person such as over 90 years old.
Orthopedic aspects of the evaluation
1. Medical history: the doctor gathers information from asking about your general health, the extent of your knee pain and how it affects your daily life, etc.
2. physical examination to check the strength and alignment of your knee joint.
3. taking X-rays to examine the extent of damage and deformity of your knee joint.
4. sometimes blood tests or other tests such as MRI, bone scan, etc. are used to examine the bone structure and soft tissues of your knee.
Based on this information and evaluation, your orthopedic surgeon will discuss with you whether an artificial knee replacement is needed to eliminate joint pain and improve function, and also consider whether other methods of treatment, such as medication, physical therapy, or other types of surgery, may be needed.
What to expect from a total knee replacement
The most important thing to know after total knee surgery is what to do and what not to do. The vast majority of patients who undergo total knee surgery will have significant pain relief and improved function to allow them to live their daily lives, but the surgery will not make the knee function any better than it did before the onset of the disease.
More than 90% of patients who have total knee surgery experience significant improvement in pain and great improvement in their ability to perform daily living activities, but an artificial knee will not turn you into a super athlete or make your knee function better than it did before the onset of the disease.’
After surgery, there are things that you will be prohibited from doing again for the rest of your life, and this includes jogging and high impact sports. Excessive activity and weight bearing will intensify the wear and tear that can loosen the prosthesis and cause knee pain for many years if the knee is used properly. Dangerous activities after surgery include running or galloping, contact sports, jumping, and strenuous aerobic exercise.