Orthopedics-Online

Operation of a knee prosthesis

Surgical preparation for knee prosthesis surgery

Since the knee prosthesis operation in anesthesia is carried out, either the family doctor or an internist must determine the suitability for anesthesia (Ability to be anesthetized). This is done by checking the general state of health. If necessary, various measures must then be taken that the ability to anesthesia produce.

This can for example

stopping certain blood-thinning medications such as Marcumar or aspirin mean (usually at least 10 days before the operation). But also certain drugs against abnormally high blood sugar (Diabetes mellitus), e.g. Metformin, must be discontinued 2 days before the operation, whereas most blood pressure medication can continue to be taken. Ultimately, these decisions about which medication to stop and when should be made together with the family doctor and the operating clinic.
or treating a Heart failure
the adjustment of the blood pressure increased blood pressure
or a possibly existing increase in blood sugar Diabetes

mean.

The clarification of the ability to be anesthetized and the associated general state of health is essential for the postoperative prognosis of the knee prosthesis operation and thus for the entire wound healing process.

In addition, various other measures can be taken that either affect the procedure itself or the rehabilitation phase and thus also influence it.

Some of these measures are listed below:

Autologous blood donation:
Since increased blood loss cannot be ruled out during knee prosthesis surgery and it is usually an elective procedure whose surgery date is fixed in advance, there is the possibility that the patient will donate their own blood in advance.This prevents foreign blood from getting into your own body in the event that a blood transfusion becomes necessary, which ultimately also excludes the risk of disease being transmitted through foreign blood.

An autologous blood donation is usually made on an outpatient basis about two to four weeks before the planned procedure. 500 ml of blood are then taken.
Cellsaver:
If cell saver systems are used in the operating clinic, it is often not necessary to donate blood. These systems clean the patient's blood lost during knee prosthesis surgery, which can then be returned to the patient in a purified state. This minimizes blood loss for the patient. The administration of foreign blood becomes rare.

Appointment with a knee specialist?

I would be happy to advise you!

Who am I?
My name is dr. Nicolas Gumpert. I am a specialist in orthopedics and the founder of .
Various television programs and print media report regularly about my work. On HR television you can see me every 6 weeks live on "Hallo Hessen".
But now enough is indicated ;-)

The knee joint is one of the joints with the greatest stress.

Therefore, the treatment of the knee joint (e.g. meniscus tear, cartilage damage, cruciate ligament damage, runner's knee, etc.) requires a lot of experience.
I treat a wide variety of knee diseases in a conservative way.
The aim of any treatment is treatment without surgery.

Which therapy achieves the best results in the long term can only be determined after looking at all of the information (Examination, X-ray, ultrasound, MRI, etc.) be assessed.

You can find me in:

Lumedis - your orthopedic surgeon
Kaiserstrasse 14
60311 Frankfurt am Main

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Further information about myself can be found at Dr. Nicolas Gumpert

Physiotherapeutic measures:
If there is severe impairment of movement in the run-up to the operation, physiotherapeutic measures should be taken before the knee prosthesis operation. Here, the muscles can be strengthened, but also better mobility, which should enable the patient to rehabilitate faster and better after the prosthesis has been used.
Inpatient admission should take place at least one day before the operation. As part of the inpatient admission, a detailed meeting all planned measures, all possible complications and Risks instead of.
The surgeon or the resident examines the patient again thoroughly with regard to the range of motion and the Belt stability of the knee joint. X-ray images that are used for preoperative drawing planning and the determination of the probable prosthesis model serve, are created.

The knee prosthesis operation

As part of a Knee prosthesis implantation different surgical steps must be performed. Since not every operation proceeds according to the same scheme, the decisive and most important steps of a knee prosthesis implantation are outlined below. The individual steps mentioned below do not claim to be complete, nor are they listed chronologically.

They are only intended to indicate which steps can usually be expected in any case. The actual operation time is between 90 and 120 minutes. However, since there are always individual differences, deviations both upwards and downwards are entirely possible.

The Narceyelet Is initiated.

The patient is "positioned" on their back on the operating table.
A blood pressure cuff is placed on the patient's thigh to hold him / her in what is known as the tourniquet (Bloodlessness) to operate. In addition to the fact that the patient loses less blood, the tourniquet in the knee prosthesis operation also allows the surgeon a better view during the actual operation.
The leg to be operated on is with Disinfectant washed off sterile.
Assessing the Leg axis, the range of motion and the ligament stability.
The exposure of the knee joint by means of a 20 cm long, front, straight skin incision.
The cutting of the joint surfaces on the thigh and tibial head using special instruments. This process is individually different, even if there is a standardized procedure for it. This technology always has to be adapted to the individual circumstances.
Removal of the abraded cartilage surfaces, the remains of the meniscus and the remains of the anterior cruciate ligament. Whenever possible, during knee prosthesis surgery, attempts are made not to damage or remove the posterior cruciate ligament (previous damage, etc.). The protection of the lateral band apparatus (inside and outside) has priority in every respect.
Inserting the Trial prosthesis. In the course of this insertion, corrections in the area of the surrounding soft tissues (ligamentous apparatus) may become necessary. If insufficient mobility or insufficient ligament stability of the knee prosthesis is determined, the above-mentioned corrections are necessary. As a rule, these measures must be taken in the case of leg axis misalignments (correction of the knock knees or bow legs).
The Original prostheses is cemented. As a rule, it is started at the head of the tibia. Only then does the cementation take place in the area of the thigh bone.
So that deeper-lying bruises can be avoided after the operation of the knee prosthesis, two so-called Redon drainage can be used. These drains lie directly in the wound and are usually removed after the third postoperative day. This skin closure is done with the help of so-called skin clips, which are removed after 14 days.
After the actual operation, the tourniquet is opened. Thorough hemostasis will (must) be ensured.

The knee prosthesis material

The demands on the material of a knee prosthesis are high. She has to charges withstand everyday life and moderate exercise, good compatible and ensure smooth use of the joint. Decades of further development of the materials used make one possible today long service life of 15-20 years with high resilience and a comparably low complication rate.

Around 150,000 total knee replacements are performed in Germany every year. Frequently used thereby special metal alloyssuch as the cobalt-chromium alloy, plastic polymers, and ceramics.
In patients with Metal allergies can look to prostheses titanium can be used.
Polyethylene, a thermoplastic material, is preferred to replace the sliding components of a prosthesis due to its high wear resistance and sliding ability.

The anesthesia

The anesthesia:
There are various anesthetic procedures available Knee prosthesis surgery to disposal:

Partial anesthesiae.g. Spinal anesthesia (Spinal anesthesia)
general anesthetic (General anesthesia)

The anesthetist (= anesthetist) points out details and possible risks of the respective anesthetic procedure during a conversation. The most suitable anesthesia is then determined on the basis of individual circumstances.
In no case can such an intervention in local anesthesia be performed.

Problems and complications

During knee prosthesis surgery:

Even in spite of the greatest care and under Consideration any individual components are in Individual cases Complications during an operation can never be ruled out. Complications that occur as part of a knee prosthesis implantation can be of various types. E.g.

Injury to neighboring structures (Blood vessels, the following blossomsNerve damage to the leg, tendons and / or muscles) occur, which may then remain partially paralyzed or require surgical treatment.
Broken bones occur. However, this is usually only the case if the patient is under osteoporosis suffers.

After knee prosthesis surgery:

Rebleeding and connected with it: Bruising (Hematomas).
A infection is the main problem of any operation. In the case of knee prosthesis implantation, infection is to be taken very seriously because of the problems that infection brings with it. Under certain circumstances, a revision intervention may then be necessary. In very unfavorable cases, the entire implant must be removed and the focus of infection cleared. In such a serious case, a new knee joint implantation would have to wait a few weeks.
If an infection turns out to be very serious, it may be necessary to stiffen the knee joint. In the process, the knee loses all known mobility, which results in restrictions in everyday life.
In very rare cases, an infection can also lead to amputation to lead.
thrombosis (= Clots in the blood vessels) can lead to life-threatening pulmonary embolisms. For this reason, as a rule, every patient receives prophylactic therapy, for example in the form of so-called “abdominal injections” and “thrombosis stockings”.
Leg length differences can be caused by the new knee joint and can therefore not be completely avoided. As a rule, the difference is not great, so it can be compensated for with the help of insoles or heel increases.
Loosening of the prosthesis - In most cases, this complication implies a replacement of the prosthesis and can therefore have considerable disadvantages for the patient.

Pain during knee osteoarthritis surgery

Pain in connection with knee prosthesis surgery is very typical and manifests itself at different points in time during the therapeutic treatment period.
Initially, pain occurs in the knee, which, due to other factors, leads to the indication of a knee prosthesis for surgery.

After the procedure, the knee is usually still very swollen and painful because the surrounding nerve, skin and muscle tissue is still irritated.
As the swelling subsides, the pain usually also subsides. At the latest after the end of the rehab, the patients should be free of pain. I.
If this is not the case and the pain persists or recurs, the cause must be found, clarified and possibly treated.

Reasons for pain after a knee prosthesis implantation can be, on the one hand, the presence of a restricted mobility, but also a loosening of the prosthesis.

The former can be caused by adhesions and adhesions in the knee joint, which must be surgically removed or treated. Calcium deposits in the muscles can also cause pain. In general, it is quite normal for the knee joint to experience moderate pain again and again due to too early or excessive stress or certain movement patterns until the knee joint has reached its full capacity for stress and function.
Typical pain-inducing movements are, for example, climbing stairs.

Furthermore, loosening the prosthesis can lead to pain. On the one hand, the loosening can have natural reasons, namely signs of wear and tear and material wear after 10-15 years.
On the other hand, however, the smallest particles can be detached from the implant due to strong friction and stress and embedded in the tissue.
The body reacts with an inflammatory reaction, which can be painful per se, and with an implant loosening, which also provokes pain. As with almost every surgical procedure, non-sterile work can lead to infection of the surgical site or deeper tissue.

Read more on this topic at: Pain with a knee prosthesis and pain after knee surgery

Duration of the operation

Surgical treatment of the knee joint with a knee prosthesis is now considered a routine procedure in most clinics with an orthopedic department.
Apart from preparation time in the form of maintaining sobriety (6h before surgery) the procedure itself takes approximately 1-2 hours.
The time measurement begins after the patient has been positioned and the leg to be operated on is evacuated, followed by induction of anesthesia.

The knee prosthesis surgery can be done in general anesthetic or Spinal anesthesia expire.

Of course, the 1-2 hours are only a guide. If complications arise or if the procedure is completely free of complications, the procedure can take more or less time.
The duration always depends on the experience of the surgeon and the operating team assisting him.

Surgery cost

Nowadays, the costs of a knee joint prosthesis are fortunately covered by both private and statutory health insurance companies.

The knee prosthesis to be implanted alone costs around on average € 8,000 to € 16,000.
Prices may vary depending on the manufacturer. However, the total costs are much higher and amount to up to € 30,000.

In addition to the knee prosthesis implant, the costs also include pre-care and aftercare. Price differences can also arise depending on the application of the process.