Arthroplasty is a surgical procedure that uses metal, polymer polyethylene, ceramic and other materials to make artificial joint prosthesis according to the form, structure and function of human joints, which is implanted into the human body through surgical techniques to improve the patient’s joint function, reduce pain, restore movement and improve the quality of life. It is the most effective way to treat end-stage osteoarthritis, rheumatoid arthritis, and femoral neck fractures. Currently, the more common types of surgery include total knee replacement and total hip replacement, with a success rate of over 90%.
In the course of the century-long development of joint replacement surgery, prosthetic materials and design processes have been pushed forward.
Currently, the artificial knee joint is made of high-tech cobalt-chromium-molybdenum alloy and ultra-high polymer polyethylene liner, and the artificial hip joint is made of bioceramic material.
Harvard University’s Bioengineering Laboratory has done a study on the service life of the prosthesis: they simulated the artificial joint mounted on a cadaver in a biological solution, simulating the movement of the human body under a gravity load of 60 kg, in the equivalent of 10 years of movement, the polyethylene liner wear only 0.2 mm. This means that it would take 100 years to reach a level of wear of 5 mm that would break the liner!
Although this is only a laboratory result and the actual service life is limited by many factors, the increasing progress in surgical methods and techniques, the emphasis on preoperative preparation and postoperative rehabilitation and care, the standardized use of intraoperative and postoperative antibiotics, and the standardized and individualized postoperative functional rehabilitation of patients have led to a gradual decrease in postoperative complications and a gradual increase in service life.
The Mayo Medical Center conducted long-term follow-up of 8,117 patients who underwent total knee arthroplasty and were able to maintain over 90% prosthesis survival at 10 years post-operative follow-up, with 84% of patients lasting at least more than 15 years and 78% lasting as long as 20 years. Hip replacement prostheses tend to last longer, with some studies showing that 90% of patients do not require revision surgery for 10 years after surgery, and the prosthesis has an 80% survival rate at 25 years after surgery.
The main causes of prosthesis failure and surgical revision are: osteolysis prosthesis loosening about 69%, joint instability 14%-15%, infection 5%-7%, fracture around the prosthesis 5%, other 5%.
Analysis of the reasons leading to the revision, the factors affecting the service life of the prosthesis can be summarized as follows.
1, patient factors
Obesity, osteoporosis, the degree of preoperative deformity of the lower extremity inversion, joint function, abnormal development of the bony structures of the lower extremity, the degree of bone defects, whether combined with diseases affecting the muscle strength of the lower extremity, can affect the survival rate of the prosthesis after surgery. In such patients, the surgery is more difficult, the possibility of encountering complications during the operation is higher, and the choice of the location of the prosthesis placement is also uncertain, which has a greater impact on the correction of the force line of the lower limb and accelerates the wear and tear of the prosthesis.
2.Surgical factors
Failure to combine the patient’s individual situation for preoperative evaluation and development of surgical plans. Intraoperative operation skill limitation, the balance of soft tissues around the joint is destroyed, and the biomechanical function is not reconstructed.
3.Prosthetic factors
There are many materials for joint replacement prosthesis, moreover, there are imported and domestic ones, and we believe that it is not necessarily the expensive ones that are good and right. Each doctor needs to choose the most appropriate prosthesis model and material according to the individual patient.
4, post-operative use factors
After surgery, patients need to be provided with a professional rehabilitation program to guide their functional exercise. Poor post-operative rehabilitation, resulting in muscle atrophy, resulting in joint instability, more likely to damage the prosthesis. Excessive exercise and incorrect joint posture, such as frequent deep squatting, leg planking, leg pressing, etc., can also cause wear and tear of the prosthesis due to excessive local stress. Improper movement can also increase the risk of trauma and cause fractures around the prosthesis.
5.Infection
Joint infection is the greatest threat to the use of joint prosthesis, the most dangerous factors, once the post-operative infection, resulting in joint pain, dysfunction, often catastrophic; if the joint infection can not be controlled, can only be revised surgery or even prosthesis removal, will seriously affect the quality of life.
Despite these factors, joint replacement is still a very mature surgical procedure.
Patients who want to extend the life of their prosthesis as much as possible after joint replacement surgery in a specialized hospital should do the following.
1, should be completely convinced of the quality and type of prosthesis used, a qualified joint surgeon will choose the most suitable joint prosthesis strictly according to the patient’s own situation, and its quality is perfectly fine for meeting their normal use.
2, need to be demanding of themselves, strict treatment, weight control, and according to the recommendations of the rehabilitation physician, the appropriate amount and accurate post-operative functional rehabilitation training, choose the appropriate exercise, not to do harmful to the life of the joint movements, to reduce the possibility of trauma.
3. Prevent various potential infections. If, after surgery, symptoms of infection in any part of the body appear, they should not be ignored and need to be treated accordingly at an early stage in the hospital. If there is redness, swelling, heat, pain and dysfunction at the surgical site, you should immediately go to the joint surgery clinic for consultation and treatment to achieve early diagnosis and early treatment of infection around the prosthesis.