The knee is the joint which connects the thigh bone (the femur) and the main leg bone (the tibia). The patella, or kneecap, is the triangular bone at the front of the knee which seals off the joint and holds the muscles of the thigh and leg. The knee can be bent or straightened and limits movements in other directions. The menisci are located between the bones. These are relatively flexible and highly resistant fibrocartilage bands that separate the femur and the tibial plateau. In addition to stabilizing the knee joint, the menisci’s main function is to act as shock absorbers for the constant pressure exerted on the knee. The ends of the knee bones are covered by cartilage. Cartilage is a kind of connective tissue which is mainly comprised of chondrocytes (egg-shaped cells with excentric nuclei, which make up adult cartilage) and collagen. Its primary function is to reduce friction between the bone surfaces and to protect bones by acting as shock absorbers for the pressure and friction exerted during movement.
Osteoarthritis results from the breakdown of cartilage, which exposes the bone. Without cartilage, the bone comes in direct contact with the meniscus, and can even rub against the other bone. This results in pain and stiffening, leading to reduced mobility. It is a progressive and irreversible disease. Physicians can only treat the pain by prescribing painkillers in line with the level of pain. They may also recommend anti-inflammatory drugs during periods of acute pain when the osteoarthritis flares up. When these drugs are no longer sufficient, surgery may be discussed. Knee replacement surgery aims to relieve pain and increase knee mobility to facilitate walking.
Knee replacement surgery
The knee prosthesis replaces the damaged cartilage with pieces of metal (chrome, cobalt, titanium, etc.) of the same shape.
One part is attached directly to the femur once the areas of damaged bone and cartilage are removed.
One part is inserted in the tibia and reproduces the tibial plateau in its normal flat and horizontal shape.
One polyethylene part is placed on top of the tibial implant in order to improve articular congruence (the state of two joint surfaces which slide over each other smoothly, without dislocating the joint), reduce friction and therefore wear and tear of the prosthesis.
One polyethylene part is sealed onto the patella to ensure greater mobility.
Depending on the damage to the various parts of the knee, the surgeon may decide to conduct a total knee replacement or a partial replacement of the cartilage.
The surgeon makes an incision at the front of the knee, of around 15 cm. The damaged cartilage and bones are removed. The prosthesis is installed. Its correct positioning may be checked using computer-aided software. The wound is closed with either stitches or clips which will be removed three weeks later. Small tubes known as surgical drains are generally left in the joint and protrude to drain fluids (serous liquid - characteristics of serosity, serum (the liquid part of blood) or having the appearance of serum - or blood) which may accumulate in the joint. A sterile dressing covers the wound and is kept on for three weeks.
Surgical drains are removed easily, without the need for another surgical procedure, on average three days later. The operation may be conducted under general anesthetic or spinal anesthetic (which acts on the bottom half of the body). The procedure lasts 75 minutes on average and requires a hospital stay of five days.
It is generally recommended that patients begin to walk again very quickly, as early as the day after the procedure. They can be assisted by physical therapy and a splint. Splints immobilize the knee for a few days maximum. Prostheses currently last for around fifteen years.
Even the most straightforward surgery could entail the risk of complications for the patient:
Complications related to the anesthetic: pulmonary, digestive or cardiac, are increasingly rare.
Intraoperative complications (which occur during the surgical procedure), in particular damage to blood vessels, nerves, bones or tendons, may be immediately reversible or, at worst, may require a new operation.
Early post-operative complications occur in 2% of cases. A hematoma which is not sufficiently drained must be removed during a new surgical procedure. Similarly, an infection may mean that the prosthesis must be removed. The procedure must then be repeated several months later. The risk of thrombosis is inherent in any surgical procedure and justifies anticoagulant treatment for one month on average.
Late post-operative complications may also occur. Joint stiffness is all the more likely since the knee was initially damaged. Unsteadiness related to tendons is generally well tolerated when it cannot be avoided. Lasting pain is generally minimal and localized.
- As each patient is different, an in-depth discussion with your surgeon is essential to gain a good understanding of the indication for surgery. Your surgeon will decide on the most timely moment to conduct the procedure according to your age, lifestyle and preferences. - If in doubt, a second opinion may help you to be clearer on your decision before agreeing to surgery. - Post-procedure physical therapy sessions are essential to prevent late complications such as stiffness or unsteadiness and to help you to resume your normal life. - Rehabilitation may continue outside of physical therapy sessions. Your therapist can teach you simple movements that will speed up your recovery.
How MSH International can assist you?
If you have limited mobility due to osteoarthritis, our medical team can refer you to a specialist who will decide if you require knee replacement surgery.
For every knee surgery precertification request, MSH International will organize a second opinion from a reputable specialist. To do so, we would ask you to send us a report from the surgeon listing prior treatment and scan or MRI images.
In order to improve your recovery, a physical therapist will also be recommended for early and effective rehabilitation.
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Knees and arthroscopy
Our knees provide us with mobility and stability, but it makes them subject to many traumatic or degenerative pathologies.