The knee joint is the joint of the body, which is already the longest and most frequently operated on joint in the body. Due to the long tradition of knee arthroscopy, the surgeons and orthopedists have the widest variety of instruments and techniques at their fingertips, so that nowadays it is hardly necessary to open the joint for diseases or injuries such as cruciate ligaments, menisci, patella and cartilage. The importance of arthroscopy as the sole diagnostic tool for the analysis of joint changes or injuries is now very much in the background, so that the arthroscopy is almost exclusively used for treatment.
Total knee replacement is a very frequent and necessary procedure to release pain and return a person to a better quality of life and activity.
Reasons For Knee Joint Replacement
Both chronic osteoarthritis and rheumatoid arthritis commonly cause people to lose knee function and damage the joint to the degree that they need a knee joint replacement (total knee arthroplasty or TKA). But knee damage may also stem from injury or infection. Sometimes, people with severe rheumatoid arthritis of the knee can require a TKA at an early age.
The treatment of osteoarthritis of the knee joint is based on the three pillars “non-drug treatment”, “drug treatment” and “operative treatment”. The therapy should always be based on a long-term perspective, may include several treatment concepts at the same time, is individually tailored to the patient and oriented to his current disease state.
Osteoarthritis has several pain causes and therefore several therapeutic approaches. On the one hand, the pain can be caused by an inflammation of the joint internal skin or by the stretching of the joint capsule, on the other hand also by bursitis and muscle tension.
Total Knee Replacement
If the osteoarthritis of the knee joint already comprises at least 2 or all 3 joint parts of the knee joint, then in principle only the implantation of a total knee joint prosthesis can be considered. This involves performing an approx. 15 cm to 20 cm long skin incision in approximately 50 to 90 minutes of surgery to replace the entire articular surface. Today’s prostheses replace only the destroyed cartilaginous joint portion and leave as far as possible the natural ligaments of the knee joint. Similar to the sled prosthesis here the attachment of the lower leg component takes place by means of cement, Cement anchoring is far superior to cementless anchoring in terms of durability in the field of knee arthroplasty. In particular, the lower leg components show in long-term studies a better durability than cementless prostheses. Cementing also has advantages in the case of replacement of the prosthesis, since the components can be removed without major bone loss, as is often the case with cementless prostheses.
Subsequently, a plastic insert is applied thereto (polyethylene). The surface of the femur is also replaced by a metallic component. Here, a special ceramic surface coating is used in our house, which leads in comparison to the classical prostheses only to low abrasion and thus a longer durability (Oxinium). In addition, thanks to its special design, this prosthesis offers the possibility of deep flexion up to 150 ° and is geared to the needs of men and women alike through its enormous variability. This surgery leads to an enormous pain relief of the patient and allows him to be able to go back pain-free. The hospital stay is typically 10 to 14 days.
Minimally invasive surgery for osteoarthritis of the knee
Already in the early 1990s, minimally invasive approaches in the implantation of sled prostheses by John Repicci from the USA were propagated (minimally invasive surgery – MIS). For the patient, the visible advantage of this method lies in the shortened skin incision. The essential factor for the surgeon, however, lies in the protection of the muscles surrounding the knee joint. This technique protects the extensor of the knee joint and allows the patient an earlier rehabilitation.
The reason for the success of minimally invasive prosthetics lies on the one hand in the surgical technique and on the other hand in the smaller instruments. This was eventually revised for total knee prostheses by various industrial partners.
The implantation of a total knee joint usually requires a skin incision of about 15-20 cm in length and an operative approach, in which a part of the thigh extensor muscles must first be separated and then re-sutured. The new, minimally invasive surgical method only needs a skin incision of about 9-12cm in length and dispenses with the separation of the muscles. This is especially caused by smaller instruments. Several studies have shown that the patients are able to mobilize faster and that the orientation important for the longevity of the prosthesis is not adversely affected. In the long run, conventional and minimally invasive patients show the same good results.
Every knee joint is different
Naturally, every knee joint is different: its anatomy, its bone quality and its clinical picture determine the individual restoration with an artificial joint, the “endoprosthesis”.
The medical-technical progress of recent years has led to the development of differentiated endoprosthesis models, which are more sensitive to individual diseases and can provide solutions for less frequent, eg local osteoarthritis damage to the knee. With so many options for care, the preparatory planning of surgery by the surgeon is an important success factor: What are the anatomical conditions? Which implant is the right one? Which implant size is the right one? So far, the surgeon plans the procedure on the basis of a conventional X-ray image and with the help of so-called “X-ray templates”, which he receives from the implant manufacturer: They are aligned to the X-ray image, so that the doctor can estimate the appropriate implant size based on his experience. The final definition on implant model and size is usually done during the operation. Only then does the surgeon see the exact condition of the knee. Thereafter, the adaptation of the implant to the anatomy of the patient with the help of a number of special instruments.
Partial Joint replacement – 2/3 Prothesis
In the event that medications, changes in your regular exercises, and stretching don’t sufficiently encourage your pain and movement, you may think about a total hip replacement surgery. Hip substitution medical procedure is a common and effective method that can alleviate your pain and discomfort. After a total hip replacement surgery most patients have normal movement return and the ability to return to a active lifestyle.
Partial Joint Replacement – Sled Prosthesis
The indication for a uni-compartmental carriage prosthesis also includes the varus or valgus osteoarthritis (X or O leg arthritis) , which is limited to the inner or outer joint space . This operation is most commonly performed in O-leg arthritis and wear of the inner joint space. In this case, a 7 cm to 10 cm long skin incision (minimally invasive surgery) is used exclusively to replace the inner joint component.
In our house here comes the prosthesis model type Oxford , which consists of a polished plate in the area of the lower leg, a sled-like skid in the area of the thigh (hence the term sled prosthesis). Between these two joint partners a movable plastic inlay (polyethylene) is inserted, which can move mobile and imitate the function of the natural meniscus. This operation can only be performed if all the ligaments of the knee joint are preserved and if the osteoarthritis in the other two parts of the joint (behind the kneecap, outer joint space) is not far advanced.
The sole wear of the outer joint space is very rare. It occurs, for example, in severe X-leg misalignment, after accidents with fracture of the bone in the outer joint part and especially after removal of the outer meniscus at a young age.
In this case, a so-called lateral slide prosthesis can then be implanted. Here, only the outer joint space is exchanged and all other parts of the joint, including the cruciate ligaments, are preserved.