A knee replacement surgery usually guarantees a life period of 20 - 25 years. But like any other part, it will undergo wear and tear during this period.
The common reasons why knees fail early includes the following.
The first three reasons mentioned above are surgeon and technique related and can be avoided by adopting meticulous techniques and using high-end technology like computer assistance. Computer helps in correct positioning of the new knee and achieving accurate limb alignment after surgery. It also helps in proper balancing of ligaments around the knee joint.
Henceforth we can safely say that with the advent of computer-assisted surgeries, the technical issues have been ironed out and fewer Revision Knee Replacement surgeries are performed to rectify the failure of earlier surgery.
The fourth cause which in fact is yet another important reason for early joint failure is infection, which can happen either within few weeks after surgery (early infection) or can happen even months or years after surgery (late infection).
Infection can lead to failure of knee replacement, requiring revision surgery but this is a rare complication occurring in less than 1% of the patients. An infected artificial knee joint might become swollen, painful and inflamed, discharging fluid or pus. Sometimes the patient may complain of persistent pain and the joint may look otherwise normal. In such cases various lab tests and scans are done to confirm the diagnosis. In long standing infection the implant might start losing its attachment to the bone leading to serious dysfunction.
We can prevent infection by utilizing the following measures:
Laminar airflow with HEPA Filters for Ultra clean Environment
Use of space suit to avoid infection
We, at Dr. Raj Kanna’s clinic, perform a two-stage procedure for the infected knee, which is a normal procedure followed by most surgeons.
In the first stage, we remove the infected knee and fill it with antibiotic cement spacer. The patient will be provided antibiotics for a minimum period of 3 months. We will then wait for the infection to subside, which might take 6 months and maybe a year. In the meantime, the patient can walk and perform routine activities that include the bending of the knees.
Antibiotic cement spacer is used
in first stage to eradicate the infection.
Once the infection is eradicated a new knee is put as a second stage procedure.
After the initial period of six months to a year, we do a set of blood tests to confirm that there is no residual infection. In the second stage, we then remove the cement spacer and put the new knee.
Other uncommon causes for failures include,
The technical issues can be treated by surgery that might include one or more of the following procedures.
Patient suffered from unstable knee after replacement surgery done elsewhere.
Patient got her instability fixed and she is now walking with a stable pain free knee.
Patient initially had both knees replaced elsewhere 15 years back. Both the knees eventually failed. Both the knees were revised on the same day with the help of computer navigation.
Before Revision: Patient’s legs were bowed because of implant failure. After Revision: The leg alignment was corrected with the help of navigation.
Failed arthroscopy is very rare. It happens when the patient suffers from pain, swelling, stiffness or locking after the knee arthroscopy, which are persistent even 2 or 3 months after the surgery.
There are many reasons for the pain, some of them include:
The patient has to understand that not all knee arthroscopy surgical procedures are the same. Sometimes the knee might take longer than 3 months to heal.
The doctors might need the following to find the exact source of the failed surgery:
The patient can mark the area of the pain and noting the other symptoms. The patients can also note the amount of physical therapy that has been performed after the surgical procedure.
The doctors would need answers to the following questions to pinpoint the exact cause of the problem:
The doctors might also do a detailed clinical examination and will study the X-Rays and pre and post-surgery MRI’s (if necessary) to distinguish the surgical changes from a meniscus tear.
Depending on the cause of the issue, the doctor might ask for further scans in relevant cases or may ask to undergo a course of physiotherapy. In few cases if the problem is technical or so, then a repeat surgery would be required.
The failed ACL and other ligament reconstruction have many causes but in majority of the cases there will be technical error in the non-anatomic graft positioning. Some of the other common causes include:
Examples of incorrect tunnel position leading to failure of ligament surgery
There will be symptomatic instability that occurs during normal and sport related activities, even after adequate rehabilitation has been performed. Sometimes there may be pain and swelling in the joint.
The doctors would first prepare the patient for surgery and then tiny incisions are created to help in Knee Arthroscopy. The knee is first evaluated and any scar tissue is removed. If the hardware placed earlier is blocking the way of the ideal tunnel placement, then it is removed.
Then doctor makes the tunnels in the right position and then passes the graft through the tunnel and fixes it with metal or bio absorbable implants.
The doctor will then remove the instruments and close the incision site. The whole surgery will be done by key hole technique, which has the advantages such as, of less pain, less blood loss, early recovery and short hospital stay.
Incorrect tunnel position (blue arrow) leading to failure. The surgery was repeated and the tunnel was made in the right place (yellow arrow)
Authored By Dr. Raj Kanna - Orthopaedic and Knee surgeon, Chennai