Prosthetic joints and revision prostheses enable people to enjoy life with pain-free mobility into old age. They are among the best researched of all medical devices. Design, materials and manufacturing methods are continuously optimized, and the surgical techniques are becoming increasingly atraumatic.
The design and proven materials used for modern prosthetic joints mean that they can last a lifetime. However, the bone in which the joint is anchored changes over the years.
Trust your physician. He knows when your artificial joint needs replacing.
If your existing implant has become loose but there is no infection, then there may be no urgency. But if the tissue around your artificial joint is inflamed, your physician will press for revision surgery at an early date so as to avoid any further complications developing.
But no artificial joint can be a 100 percent replacement for the original joint. Each time surgery is performed, scar tissue occurs and, at the same time, muscle, bone and tendon substance is lost. For this reason, you may need to use a walking stick or crutch after the operation, and/or you may have to do gait training to improve your walking ability.
Whenever a revision surgery is performed, it can be a challenge for the surgeon to fix the new joint firmly in the bone.
This is because when the old implant is removed, some bone is usually lost and has to be replaced with bone from another part of the patient’s body, or bone graft material from the bone bank, or bone cement.
The first step in your revision operation is for the surgeon to remove the existing implant, while attempting to conserve as much healthy bone as possible. He then implants the revision prosthesis or components.
If you have a bacterial infection, there are two possible procedures. Either the surgeon implants the revision prosthesis immediately using a bone cement tailored to the spectrum of bacteria present. Physicians refer to this procedure as single-stage revision surgery.
Or the surgeon first replaces the artificial joint with a spacer so that the infection can be treated over a period of time. Later, a second operation is performed in which the surgeon removes the spacer and implants the revision prosthesis. Physicians refer to this procedure as two-stage revision surgery.
The main criterion on which the surgeon decides which procedure to use for your revision surgery is the state of the bone and tissue. The patient’s circumstances and general state of health, and also the type and duration of any infection, also play a part in this decision.
High-grade materials for prosthetic joints
Replacement hips comprise an acetabular cup and a stem, onto which a prosthesis head is attached. The acetabular cup is usually made of a special plastic (polyethylene) or a metal shell with a plastic or ceramic inlay.
All types of prosthesis undergo extensive testing, in which their function, quality, reliability and safety are checked against international industry standards.
Revision prostheses for knee and hip joints can be classified like “normal” joint replacements, e.g., according to
If necessary, revision prostheses can be also be customized to precisely suit the patient’s requirements. For example, for patients who suffer from a metal allergy, the surface of the prosthesis can be coated with a material that prevents migration of allergenic metal ions.
Especially for young patients with biologically vital bone, a short-stem prosthesis is often used for the first replacement. The reason for this is that the surgeon has to remove less healthy bone when a short stem is implanted. A revision prosthesis, on the other hand, usually has a longer stem so that it can be anchored deeply and securely in the thigh bone. The stem must extend deeper into the bone than the “bed” of the first joint replacement.
Just like your first joint replacement, your revision joint should be as perfect a replacement as possible for the natural joint. So it must be located in the bone securely and with millimeter precision. In addition, it has to bear the load of your bodyweight and be able to perform normal everyday movements.
The material of the implant needs to be durable, extremely low-wear, and well tolerated by the body. It should promote bone ongrowth and have anti-bacterial properties to prevent infections. This enables the implant to withstand daily loads over many years. Your physician will discuss with you which type of revision joint replacement is most suitable for you. Whether to implant a “short” or “long” hip replacement, for example, is a decision that the surgeon may only make during the actual operation.
Replacement joints can be fixed in the bone either with or without bone cement. What technique the surgeon uses for the revision depends in part on how your first replacement joint was implanted. The surgeon always attempts to conserve as much healthy tissue and bone as possible. He will decide on a case-by-case basis whether your revision joint replacement should be implanted with or without bone cement. Implants fixed with cement are suitable principally for patients with poor bone vitality.
Every artificial joint and revision joint is the product of state-of-the-art precision engineering and craftsmanship.
Nevertheless, even the wide range of standard implants do have their limitations. For example, if all the bones in a patient’s thigh have to be replaced, or if a tumor causes a particularly large bone defect. Often, in such cases, the only way in which the patient’s mobility can be preserved is with a custom-made implant.
In close collaboration with the surgeons, customized replacement joints and revision replacements are designed by engineers at LINK and custom-made in Germany.
At the surgeon’s request, the surface of replacement joints and revision replacements can be specially coated or modified.
Surgeons perform joint operations with instruments specially developed for that purpose, so usually only small incisions need to be made. This helps to conserve the muscles and bone, so you are back on your feet
quite quickly after the operation. You too can play a role in making your revision operation a success:
Like most patients, you may be able to stand up again just a day after your operation. However, you still need to be careful. Your physician knows which movements you should avoid and whether you should use crutches.
Rehab at a clinic or at an out-patient center begins a few days after the operation. Training will make your muscles stronger each day, and this will help to stabilize your revision joint replacement. You then have every prospect of being able to walk pain-free and without crutches just a few weeks after the operation, like most patients.