Revision Knee Replacement Surgery
Revision Knee Replacement Surgery: Patients with knee prostheses may experience loosening of the prosthesis after a certain period. This loosening can occur due to various reasons such as infection, instability, wear of the polyethylene (special plastic between two metals), or fractures. In such cases, the prosthesis needs to be replaced with special prostheses, which is referred to as revision knee replacement surgery.
Before revision knee replacement surgery, it is crucial to determine the cause of the prosthesis loosening. This involves examining the patient’s knee films, possibly a CT scan, and analyzing blood tests for infection and rheumatological markers. The primary distinction to be made is whether the loosening is due to infection or instability. To achieve this, special tests may be required, including blood samples, cultures from the knee, bone scintigraphy, or leukocyte-labeled bone scintigraphy, and alpha-defensin testing. The results of these tests will guide the chosen approach. If there were prolonged wound healing issues and discharge after your initial surgery, the likelihood of long-term infection-related loosening is higher.
The most important reason for revision knee replacement is polyethylene wear or loosening of the metal surface, leading to instability and causing pain and mechanical issues (such as noises from the knee and reduced range of motion). In such cases, the old prosthesis is removed, and a new one is inserted in a single surgery, allowing the patient to quickly return to daily life and improve their quality of life.
In the case of infection, things can be more complex. Your doctor may decide on a single or two-stage surgical approach based on the type of bacteria causing the infection and its extent. The generally accepted approach is a two-stage surgery. In this process, the first stage involves removing the infected prosthesis, cleaning the joint, and temporarily placing an antibiotic-prepared spacer in the knee joint. During this surgery, tissue samples are taken to identify the type of bacteria causing the infection and which antibiotics are effective. The patient receives antibiotic treatment based on these results between the two surgeries. Once the doctor is sure that the infection has resolved (by checking blood tests and examining the wound), they will decide on the second stage. At this stage, the spacer is removed, and special prostheses are placed in your knee, allowing you to return to daily activities. If the cleaning in the first stage did not adequately control the infection, it may need to be repeated several times.
This two-stage surgery takes a minimum of four weeks and may be extended depending on the extent of the infection and the antibiotic therapy provided.
Revision knee prostheses are generally larger than primary knee prostheses. They may have extensions that go into the bone to increase the contact surface and stability. In very advanced cases, where there is significant bone loss and the collateral ligaments are not intact, partially restrictive prostheses may be preferred.
Post-Operative Care
Patients are taken to the ward for rest after surgery. Many patients are supported to walk the day after surgery. After revision knee replacement, patients typically stay in the hospital for about 4-5 days for wound care and intravenous antibiotic treatment. Unfortunately, due to the size of the surgery and the repeated surgical nature, the infection rate in revision knee replacements is higher than in primary knee replacements, requiring close monitoring.
Patients may walk with support for about a month and then can walk without assistance. The expectation after revision knee replacement is for the patient to walk pain-free, perform daily activities independently, and sit and stand comfortably. Due to the restrictive nature of revision knee prostheses, strenuous sports are not recommended after surgery. Patients can engage in lighter activities such as walking and swimming.
Questions and Answers
It has been a long time since I had my knee prosthesis, and I am experiencing pain. Can it be determined if it is loose from the films?
Yes, a simple X-ray can provide a lot of information regarding the loosening of the knee prosthesis. In particular, comparing follow-up images (with your previous films) can show changes in the prosthesis position or the formation of gaps between the prosthesis and the bone, indicating loosening.
I previously had a knee prosthesis revision. However, I am now experiencing pain again, and it has been suggested that it needs to be changed again. Is a revision possible?
A revision can be performed after revision knee replacement; however, more significant bone loss and losses in ligaments and soft tissue may require larger and more restrictive prostheses.
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