Knee replacement surgery

The purpose of knee replacement surgery

Knee replacement surgery is the second most common major joint replacement surgery among orthopedic surgeries. This is not surprising, since we use our knees almost constantly, hence they are constantly exposed to the risk of wear and tear and accidents.

The knee is the largest and most complex joint in the body. It consists of the joints at the junction of the femur and the tibia, and at the femur and the patella.

What are the causes of knee joint wear?

Some of the wear and tear of the knee joint is caused by previous developmental abnormalities (knee joint misalignment, torsional deformities), growth problems in children and adolescents, circumscribed circulatory disorders, inflammatory diseases, joint surface disintegration due to bone injuries, and instability caused by ligament tears and meniscus injuries. In other cases, wear and tear of the knee joint may develop without any identifiable predisposing factor, which in medical terms is referred to as primary knee osteoarthritis.

In both cases, there is a gradual onset of knee pain, swelling, joint effusion, joint instability, and occasional locking or clicking sensations. Initially, walking up and down stairs becomes difficult. The initial complaints of exertion may, over time, develop into pain at rest and even significant pain at night.

The range of motion gradually narrows. At first mostly full extension is lost, then flexion becomes limited, and in more severe cases, limping may develop. Occasionally the patient may also notice a difference in limb length due to a lack of extension of one knee. All these gradually limit walking, initially on stairs or uphill, and later on horizontal ground.

In which cases is a knee replacement necessary?

The initial treatment options may consist of a combination of exercise, swimming, physiotherapy and various cartilage-supporting medications. Later, in addition to anti-inflammatory, analgesic and relaxing medications, physiotherapy and balneotherapy options may help to alleviate symptoms.

If these treatment options are exhausted or do not provide the expected quality of life and physical performance, surgery may be considered. In the early stages of the disease, arthroscopic or minimally invasive options may be considered. Cartilage resurfacing, cartilage replacement, axis corrections, stabilisation surgery, and arthroscopic resurfacing are biomechanical reconstruction options with well-defined indications, all of which can provide good results at an early stage, even in the case of surface damage in only part of the joint.

If the joint wear is extensive and advanced, endoprosthetics or knee replacement may help. The aim is to eliminate or reduce pain, increase the reduced range of motion as far as possible, restore stability and improve weight-bearing capacity.

Knee replacement implants

What happens during the operation?

The aim and purpose of knee replacement is to replace the damaged joint surfaces. This is done by replacing the knee joint surfaces of the femur and tibia (in very rare cases, the inner or outer joint surface may be replaced, known as a microplasty or unicondylar sled prosthesis). In most cases, the kneecap joint surface is also replaced. During the operation, metal implants are inserted on both sides into the accordingly prepared receptive surfaces, with an ultra-hard polyethylene insert placed between them to ensure proper, easy gliding.

Knee replacement fixation techniques

The implants are fixed into the bone with bone cement containing antibiotics. This is a widely used fixation solution, but in our hospital, we also offer the possibility of cementless knee replacement. This has long-term benefits but requires good bone quality. At our hospital, we choose this type of implantation whenever possible, which can be decided definitively during surgery, depending on the bone quality and the condition of the kneecap. In all other cases, we use bone cement to ensure proper fixation.

For metal-sensitive patients, our hospital also offers the possibility of titanium-coated implants.

What improvement can I expect from the surgery?

Minimally invasive surgical techniques are now a basic requirement for rapid rehabilitation and better long-term results. This involves avoiding the dissection of muscles and tendons in order to spare the soft tissues as much as possible. This, together with the adequate initial stability of the implants, ensures that our patients can bear their full bodyweight on their operated limb on the day after surgery.

If our patients present for surgery with more significant ligament damage or bone mass deficiency causing instability, we have special implants available to address this (called posterior-stabilized, constrained condylar or modular augmentation implants). These options also usually ensure immediate full bodyweight bearing.

Preparations and procedure for knee replacement surgery

Preoperative period

The surgical recommendation is made on the basis of the patient’s medical history, an outpatient physical examination, bodyweight-bearing x-rays and other imaging studies (CT, MRI, bone scintigraphy) as necessary, and possibly other additional tests. This will include planning the type of implant, the method of insertion and some important technical details of the surgery. When making the proposal, we will explain the main elements of the aftercare, the rehabilitation schedule and answer any questions you may have about the operation during the consultation.

The patient will then be given a written preoperative diagnostic review, together with further details of the hospital stay associated with the surgery. At this time, we will arrange any necessary preoperative tests and a subsequent anesthetic consultation. If the offer of surgery is accepted, we will set a date for the planned surgery.

During the anesthetic consultation, we will decide on the planned anesthetic method. Knee replacement procedures can be performed under regional spinal anesthesia or general anesthesia. The choice of the type of anesthesia and the determination/modification of any medication required prior to surgery (e.g., switching to blood thinning medication) is made in consultation with the anesthetist, based on the patient's medical condition and prior investigations.

The surgery is performed on the day of admission after adequate preparation.

The operation

Before, during and after the procedure, we use drug prophylaxis and physical preventive measures to control the most common complications. These include antibiotic prophylaxis to reduce the risk of infection and prophylactic treatment against blood clots (blood thinners, surgical dressings).

Appropriate analgesic and anti-inflammatory treatment is also started in the operating theater and continued in the ward. The nursing staff is always available via the nurse call line for both pain relief and all other care and comfort issues.

During surgery, a suction drain may need to be inserted to remove post-operative bleeding and will be removed the day after surgery. The urinary catheter inserted during surgery will also be removed the following day.

Post-operative tasks

The day after surgery, we will start mobilization with the help of the physiotherapist. Although knee replacement surgery allows the patient to immediately step onto the operated limb with their full bodyweight, the physiotherapist will provide a walking aid to help with walking safety during the initial period. The type of device (elbow brace, underarm brace, walking frame) is determined together, taking into account the patient's physical parameters.

During the three days of the hospital stay, in addition to teaching the patient how to walk and climb stairs safely, the physiotherapist will demonstrate the home exercises required initially during the ward physiotherapy session. In some cases, to reduce swelling and achieve improved bending function, the physiotherapist will also fit a knee-joint machine for 30-120 minutes a day to provide pain-free passive movement.

First weeks after surgery

Patients leave the hospital on the third day after surgery in a condition to walk and climb stairs at home. The journey home may be in a car with the option of sitting with the knees slightly bent.

During the first two weeks, prolonged flexion of the knee joint above 90 degrees may cause strain, swelling and wound healing difficulties. At the time of discharge, prescriptions for the necessary medication (blood thinners, anti-inflammatories, painkillers, gastroprotective medication, etc.) are provided and the discharge report includes a recommendation for home therapy.

After a three-day hospital stay, our postoperative patients are usually discharged in a physical condition that allows them to care for themselves without requiring constant home care. However, for a few weeks, they may still need the support of a family member or friend to help with shopping or running errands outside the home.

What to look out for after knee replacement surgery?

Rehabilitation after knee replacement surgery

It is not usually necessary to change the dressing that was put on in the hospital while recovering at home. The wound should not be exposed to water until the stitches are removed. If the dressing is damaged or bleeds through, it can be replaced with a dry top dressing. In most cases, no special physiotherapy is needed in the first few weeks; it is sufficient to repeat the exercises learned in hospital at home, as agreed. Some patients soon develop a degree of walking security that allows them to leave the home without the use of a walking aid.

Postoperative follow-up tests

First check-up

The first postoperative check-up comes after around 10-14 days, when the sutures and stitches are removed. The dressing applied at this time can be removed within 1-2 days and showering can be continued without wound protection. Anti-inflammatory therapy and thromboprophylaxis with tablets or injections should be continued for the period prescribed at discharge. Most of our patients are usually able to resume short or long walks outside the home at the time of the first check-up. It is not advisable to start driving before four weeks have elapsed.

Second check-up

The second check-up is due after 4-6 weeks, at which time an x-ray is taken to check that the implant is in the correct position and is properly fixed. After assessing the range of motion, walking ability and muscle strength, we will determine whether additional physical therapy is needed in our hospital or elsewhere.

The majority of our patients have sufficient function at this stage and do not require organized physiotherapy, and the exercises they have learned, or home-based physiotherapy is sufficient to achieve good daily physical activity.

During this period, stretching is usually complete and well developed, flexion is above 90 degrees, and the thigh muscles have started to recover. The emphasis is then on flexion exercises and hamstring strengthening, so in addition to physiotherapy, we recommend indoor cycling and strengthening the hamstrings on gym machines.

Third check-up

The third follow-up test happens between 2 and 3 months post-op. By this time, we expect to see that everyday activity is functioning at the desired level and that the patient is able to take up more demanding sporting activities. If function is adequate during this period and the prosthetic joint is comfortable and performing well, a follow-up examination is only necessary at the end of the first year after surgery. At that time, the implants and the function of the operated joint are again checked by x-ray.

Further check-ups

Even in the absence of a complaint, we consider it necessary to continue to x-ray the operated knee every two years.

Possible complications

The outcome of knee joint replacement depends on a number of factors, of which the general musculoskeletal condition of the patient, the limitation of other joint functions and the level of previous physical activity play a significant role in the outcome.

Swimming, cycling, hiking and training on gym machines are highly recommended, but running, tennis, cross-country skiing and similar sports are not prohibited if the patient is in good physical condition. However, so-called contact sports, which involve jumping and collisions, should be avoided.

Sauna and spa use is allowed three months after surgery, but it is advisable to limit the time spent in water warmer than body temperature to 10-15 minutes.

Frequently asked questions about knee replacement

What movements are forbidden?

There are no specific movements that are forbidden, but during the wound healing period, prolonged flexion above 90 degrees can impede wound healing and cause increased leg swelling. In the first weeks, movement and walking will help the circulation of the limb, but in the case of prolonged sitting, we recommend elevating the limb to avoid swelling of the knee and peripheral edema.

What medical aids are needed for physiotherapy at home?

We provide all the medical aids needed during rehabilitation in our hospital that may be necessary when our patients leave for home. These include support stockings to protect against blood clots, walking aids (underarm or elbow crutches, a walking frame or walking sticks), toilet aids.

In consultation with a physiotherapist or doctor, it may be useful to hire a passive knee exerciser to supplement home exercise in the two to three weeks following surgery to help regain knee function more quickly. It should be stressed that this is not a substitute for active exercise, but a complement to it. The final function of the knee joint will be determined largely by the physiotherapy, active stretching and flexion exercises, and muscle strengthening.

Can I have an MRI scan with the implant?

Medical metals are generally MRI compatible, so MRI scans can be performed after long-term knee replacement. Since medical metals can heat up minimally in the magnetic field, we do not recommend MRI scans in the first six weeks after surgery, the early post-operative period, but it can be done afterwards.

How does the implant behave at airport or other metal detector gates?

The implant can be detected by a metal detector. Neither the hospital discharge report nor any other certificate will exempt you from being screened with a handheld metal detector, because these checkpoints are basically designed to detect metal weapons, so that is what the inspection is aimed at.

When can you start driving a car with a knee replacement?

After unproblematic implants, it should be 4-6 weeks after surgery before we recommend you resume driving. This period may be shorter for left knee surgery and automatic cars.

What sports activities can I do after a knee replacement?

Knee replacement surgery does not exclude subsequent sporting activities. On the contrary, the aim of the operation is to enable the patient to lead as full and active a life as possible, free from pain and regaining his or her previous mobility. The pace of the gradual return to sporting activity is determined by the doctor and the physiotherapist and is determined not only by the function of the operated joint but also by the patient's other parameters and general musculoskeletal condition.

In general, swimming and cycling are recommended after 3-6 weeks, and sports activities involving rotational movements and running after 8 weeks. In the long term, we discourage our patients from sports activities involving impact and contact sports.

Why choose Dr. Rose Private Hospital? 

• We offer a full range of orthopedic services. Our orthopedic specialists provide the necessary tests (MRI, CT, x-ray, ultrasound, laboratory tests) to make an accurate diagnosis. Knee replacement surgery is performed without a waiting list. After the operation, our physiotherapists and sports rehabilitation staff will help you to regain your mobility as quickly as possible.
• A highly trained team of specialists. Our specialists use state-of-the-art, minimally invasive techniques to speed recovery, complemented by our physiotherapists, manual therapists and sports rehabilitation staff. For complex problems, we decide on the appropriate course of treatment, necessary tests and therapies in a consultation.
• Exclusive environment. Our premium in-patient department has 3 operating theaters and 24 patient rooms with 33 beds to meet all your needs. The highest professional standards, together with a unique healing environment, mean you can recover in safety and complete peace of mind.

For knee pain and complaints related to the knee joint, please contact the doctors at Dr. Rose Private Hospital.