Hip arthroplasty is a surgical technique in which an artificially designed joint prosthesis is implanted to replace our diseased joint. As with other organ transplant techniques, it is a procedure that requires a high level of surgical conditioning and skill. This technique has become the most established surgical procedure in joint surgery, and hundreds of thousands of people are relieved of joint pain each year as a result of this procedure.
If for some reason your joint has been more severely damaged, hip replacement may be the best treatment available. Unfortunately, with the current state of medical development, artificial joints have a limited life span.
If you have already had a hip replacement, you may be faced with the problem of replacing it again after a number of years of use (usually 10-15+ years, but a few will go wrong in a much shorter period of time).
Doctors refer to the first artificial joint replacement as the initial replacement and the second replacement of the same joint as a revision.
Why do you need a hip revision?
A hip revision is often necessary after an arthroplasty for the following reasons.
1. Mechanical loosening
Mechanical loosening refers to the loosening of the connection between the prosthesis and the bone due to non-infectious reasons. There are many reasons for loosening. Theoretically, whether or not bone cement is used during surgery, sooner or later the implant will have to loosen because humans have not been able to make the implanted joint “grow” with our bones. This is why doctors always wait until the joint absolutely needs to be replaced before performing the surgery. The younger you are, the more active you are, the longer you will need to use it, and the more likely it will need to be rebuilt due to mechanical loosening.
2.Infection
Infection after artificial joint replacement is a serious condition. Despite decades of development, infection after hip implantation is still unavoidable, and even in some internationally renowned joint surgery centers, the incidence of infection is still around 1-2%. Once infection occurs, the prosthesis may become loose due to the infection and often the prosthesis has to be removed and post-infection revision surgery performed in order to cure the infection.
3.Fracture
It is rare for fractures to occur near the implanted prosthesis after artificial hip implantation. Once it happens, it is sometimes necessary to remove the prosthesis and implant a new one to facilitate the fixation of the fracture and the stability of the prosthesis.
4.Artificial joint instability
Artificial hip instability refers to the occurrence of joint dislocation after artificial joint implantation. As our own joints sometimes dislocate, artificial hip dislocation cannot be completely avoided, especially if the patient cannot use the joint according to the above instructions. Occasional dislocations can mostly be used normally after a period of healing and repositioning by a physician. However, if the dislocation occurs repeatedly, the artificial joint is really unstable and may need to be reimplanted, i.e., a revision of the artificial hip joint.
5. Wear and tear
As doctors advance in their techniques to prevent loosening of the prosthesis, it is becoming more common to see wear of the polymer PVC (a type of plastic) component of the artificial joint as the prosthesis lasts longer. This component acts as an artificial acetabular prosthesis or as the lining of an acetabular prosthesis to replace the acetabulum of our joint. The femoral head prosthesis is usually metal and the acetabular prosthesis is made of polymer polyvinyl chloride. The two are matched to form an artificial joint and have long been considered the best match one can find, precisely because there is very little friction between the two. But very little, not non-existent. As long as friction exists, wear and tear of the plastic parts will occur over time. In some cases, wear may even occur at an earlier age, for reasons that are not yet understood, in addition to the quality of the plastic material, the way the artificial joint is used, and other factors.
6, osteolysis
Osteolysis is the inexplicable dissolution of the bone around a joint prosthesis! In fact, sometimes osteolysis can be so severe that, for example, the surgeon finds a large cavity around the prosthesis during surgery.
A large cavity has formed, leaving only a thin layer of bone shell. Recent studies have found that, in addition to the direct damage to the plastic components, the plastic particles formed by wear and tear can gradually lead to the dissolution of the bone around the prosthesis, eventually leading to loosening of the prosthesis. In fact, with the progress of artificial joint implantation technology, the bone dissolution caused by wear particles has gradually become the first cause of prosthesis loosening.
7.Prosthesis fracture
The prosthesis can fracture under the repeated fatigue stress of daily activities, but this is an extremely rare case.
Second, the preparation before the artificial hip joint revision surgery
Hip revision surgery is very complicated due to various complications such as infection, osteolysis, difficulty in removing the prosthesis or bone cement, etc. It is completely different from the initial replacement.
Before surgery, the surgeon usually has to rule out infection first. Blood tests may be taken, nuclear scans may be ordered, and sometimes fluid may be aspirated from the joint to detect possible signs of infection. The doctor may also order x-rays to determine the quality of the bone, measure the size of the new prosthesis, etc. In fact, in many cases, the surgeon will have to prepare a variety of special prostheses for the revision surgery in order to deal with the various complications that may be encountered during the surgery.
Third, the procedure of artificial hip revision surgery
Hip revision surgery usually requires a larger incision than the first surgery, most of the time the first incision is extended, or sometimes another incision is made. The surgeon first removes the scar tissue from the first surgery, tries to remove the original joint prosthesis, removes any unhealthy or infected tissue, and removes as much bone cement as possible if it was used during the first surgery. Bone grafting is then used to replace the missing bone, and a suitable joint prosthesis is selected for implantation. After the joint is tested for stability, the incision is closed.
Fourth, if the original joint damage was not severe, the surgery may be very smooth. Otherwise, the surgeon may encounter several difficulties as follows.
1. Bone defects.
Revision surgery often encounters bone defects around the original prosthesis, as mentioned earlier. In this case, bone grafting is needed. If the amount of bone grafting needed is small, you can implant your own bone, for example, from the pelvic bone; if the defect is large, you need to transplant someone else’s bone (currently there are finished products). Generally the own bone is easier to heal.
2, the original prosthesis removal difficulties.
Often encounter the original prosthesis removal difficulties, sometimes part of the prosthesis loose, another part also had to be removed, forced to remove will cause fractures.
3.Difficulty in removing bone cement.
If the original prosthesis is fixed with bone cement, even if the prosthesis is taken out, it is very difficult to take out the bone cement. Because the cement is connected to the bone, the cement often has to be chiseled out little by little, which often causes fractures in the process.
4. Infection is found to exist in the original joint.
Infections or suspected infections are often encountered. In this case, the doctor will send the suspected infected tissues to the laboratory. If the laboratory results suggest infection, the doctor will remove the infected tissues in a strict and comprehensive manner before implanting the prosthesis, but more doctors will choose to abandon the implantation of the artificial joint and close the incision after removing the infected tissues. When the infection is completely controlled, the artificial joint is surgically implanted again.
In extremely difficult cases, the surgeon may find that the bone is severely defective or that the infection is so severe that the idea of implanting an artificial joint has to be abandoned forever.
5. Recognize the risks of hip revision.
All of the risks of initial replacement may occur during revision surgery. In addition, because revision surgery of the artificial hip is much more complex than the initial replacement, the following points should be particularly emphasized.
6. Risks of anesthesia.
Since artificial hip revision surgery is usually used for the elderly, the risk of anesthesia is greater due to the weaker body and longer operation time. Please communicate with the anesthesiologist carefully before the surgery and fully understand the risk of anesthesia.
7.Thrombosis and pulmonary embolism.
Thrombosis refers to the clotting of blood in our body to block blood vessels, which mainly occurs in the veins of the lower limbs and deep abdomen, also called deep vein thrombosis. Thrombosis can occur after any surgery, but is most common after hip, knee and pelvic surgery. When thrombosis occurs in the deep veins of the limbs and abdomen, the lower extremities become swollen and painful. But the scariest part is that these emboli occasionally dislodge and then travel down the bloodstream to the lungs, blocking the blood vessels in the lungs and causing what is called a pulmonary embolism. The most serious is a fatal pulmonary embolism, which is often too late to save because of the severity of the blockage. Fortunately, this is a very rare occurrence. All doctors who perform joint replacement surgery take the prevention of thrombosis seriously, such as not using hemostatic drugs before and after surgery, applying anticoagulants prophylactically, encouraging early bedtime activities, etc., but all these methods cannot eliminate the occurrence of thrombosis.
8. Post-surgical infection.
Infection may occur in any surgery, but infection after artificial joint replacement is a difficult complication to deal with. The chance of infection after an artificial hip revision is about twice that of the initial replacement, and once it occurs it is more difficult to control than after the initial replacement. Doctors will do everything they can to prevent infections from occurring. After you are discharged from the hospital, but any infections in other parts of your body, such as gingivitis, pneumonia, enteritis, etc., must be treated as soon as possible to prevent bacteria from running near the joint prosthesis via the bloodstream. If you need surgery for other diseases, you should also tell your doctor that you have had joint replacement and ask him to apply antibiotics before and after the surgery to prevent bacteria from running from the incision to the vicinity of the artificial joint.
9. Joint dislocation after surgery.
Just as our own joints sometimes dislocate, artificial joints can also dislocate. Especially in the early post-operative period, the tissues encircling the artificial joint have not yet healed and there is a higher chance of dislocation. Doctors and rehabilitators will teach you repeatedly before and after surgery how to position the limb and how to use the limb and your new joint properly after surgery. However, the artificial hip revision surgery may encounter some extremely difficult situations, which may lead to a very easy dislocation early after the surgery. In this case, the doctor may keep you in bed for a longer period of time to wait for the tissues to heal and strengthen the stability of the joint. This is, of course, not a common occurrence.
10. Periarticular ossifying myositis.
Ossifying myositis refers to the growth of something like bone in the muscles around the joint, causing the muscle tissue to harden and adhere to each other, thus reducing the range of motion of the joint and stiffening the joint. Because of the high degree of trauma associated with a hip revision, there is an increased chance of developing osteomyositis around the joint. Once it occurs, your doctor may order oral medication (such as indomethacin) or use local radiation therapy to reduce the extent or slow the progression of the lesion. After the onset of ossifying myositis, it usually stops progressing after a period of time. At this time, if the joint joint movement is significantly limited, your doctor may recommend that you surgically remove the ossified tissue to improve joint function.
11.Artificial joint loosening again.
The chance of loosening of the prosthesis after the artificial joint revision surgery is much greater than the initial replacement. After loosening occurs, if the pain is significant, sometimes you have to operate again to replace the joint.