Knee - Endoprostheses

Modern surgical techniques and the right implant provide a safe and long-lasting alternative.

There is a variety of implant types, designs and material alloys for every joint. It can be cemented into place, i.e. using a bone adhesive, or incorporated directly into the bone. For knee prostheses, it is essential that there are different degrees of attachment between the components – from unjointed models to rotating hinge prosthetics. The attending surgeon’s expertise and skills are as always essential to the success of the procedure. He must decide in the course of the operation the prosthesis most suitable to the patient’s needs and, importantly, have the surgical technique specific for that prosthetics well-honed.

Expertise und skills

Dr. Sarem, head of Joint Care Center, is a specialist consultant on knee and hip prosthetics; he has conducted over a hundred prosthetic operations at the Berlin Havelklinik.

Whenever possible, we prefer the surgical method to be minimally invasive. This tissue-conserving procedure is performed through a tiny incision in the skin; bones, surrounding ligaments and muscles, as a result, are impacted as little as possible. This procedure ensures the patient experiences minimal post-op pain and a briefer recovery process. The operation lasts 1-2 hours and takes place at the Havelklinik. The hospital’s modern equipment and highly qualified nursing staff ensure the patient achieves a sense of well-being and a comfortable recovery. The hospital stay generally lasts 10 to 14 days. For the subsequent rehabilitation treatment, 3-weeks are recommended.

Single-sided resurfacing

Joint resurfacing is suitable in about 5-10% of patients with arthritis of the knee. In keeping with the principle: as much as necessary, as little as possible – we replace the defective portions of the joint with a femoral sled prosthesis. The procedure is minimally invasive: ligaments and tendons are maximally conserved. The advantage of the technique is a quick recovery time and good mobility afterwards. This procedure is however only possible if all the other parts of the joint are healthy.

Complete resurfacing

This operation also replaces only the defective portions of the cartilage with an artificial surface. The replacement can often be carried out, as a minimal access procedure, though a tiny incision in the skin. Bones, ligaments and neighboring muscles are treated with great care and conserved. The defective cartilage portion of the thigh bone is replaced by a metal surface. Its joint counterpart on the shinbone is given a metal surface bonded to an artificial component.

Computer navigation: to ensure precise positioning

In many cases we use computer navigation to fit the prosthetic components. This state-of-the-art technique facilitates the exact measurement of the joint as well as calculates and details the best way to position the prosthesis.

Types of prostheses and fixation

There is a variety of prosthetic joint replacements available: material, size, form and fixation techniques, to accommodate the specific needs of individual patients. Modern, high-grade quality prosthetics are made of non-allergenic materials. Frequently the prosthetic surface facing the bone is roughened to give new bone tissues grip so that they can grow into it which helps to anchor the new joint to the bone.

The cemented implant has a somewhat modified back for the take-up of the bone cement. Since the cemented fixation is just as durable as the non-cemented kinds, the decision must be discussed between the surgeon and the patient.


The prosthesis is usually composed of three parts: the thigh-bone implant, calf bone implant and kneecap replacement.

Subsequent rehabilitation

Under the supervision of a physiotherapist, you will begin learning how to use your joint again. By the time you are discharged from the hospital you will have mastered common, everyday movements. Dr. Sarem and the hospital’s administrative staff are in charge of coordinating these vital steps.


A subsequent rehabilitation following the procedure generally leads to a quick recovery.

We continue to be at your side after your discharge from the hospital. ZATT (Center for Analysis, Therapy and Training), which is part of the CHIMANOS Joint Care Center, provides you with state-of-the-art rehabilitation medicine and technology. In order to ensure your therapy be optimal and tailored to your exact needs, ZATT’s therapists are in constant consultation with your attending doctors. Our patients are thus reassured that they are in the best of hands.

After a further 3 weeks of rehabilitative care the patient can generally resume their professional or sports activities. We will closely monitor and aid you during this process.



We use abrasive-resistant components to avoid the risk of premature loosening up of the joint, which if allowed to happen would require additional surgery.

Durability of knee prosthetics

Knee prostheses last about 12-15 years. Factors like material, positioning of the implant as well as the patient’s physical activities and bone quality are vital to an implant’s service life. In many cases, we employ a navigational device during the operation, which is especially important when performing corrective surgery on knock knees. The state-of-the-art material we use for the prosthetics has a significantly longer life span than other available options.

Reason for replacing a prosthesis

Since the knee is subjected to a great deal of strain, signs of wear and material abrasion on the artificial components are important. These factors lead to the loosening of the prosthetic parts on the bones which over time causes ever increasing pain to the patient. Incidents like accidents and infections can also cause the prosthetics to loosen. If tests reveal this to be the case, then the prosthesis will have to be replaced.