Artificial Hip Joint – Primary Total Hip Arthroplasty
The surgery of an artificial hip joint is performed with a minimally invasive technique. With this special technique, the muscle insertions remain completely preserved. Due to the smaller skin incision and subsequently to the reduced surgical trauma, the patients are able to mobilize in a very short time.
The digital planning helps the surgeon to easily find the correct position of the implants, equalizing leg length discrepancies and keeping the tension of the muscles in the correct way. At the Orthopaedic Clinic Gersthof approximately 400 such hip replacements are performed yearly.
The principal surgical steps performing total hip joint replacements are shown in the following illustrations:
1. Preoperative X-ray of the affected hip.
2. Preoperative digital planning of the implant position
3. Removal of the femoral head
4. Implantation of the new acetabular cup
5. The new acetabular part of the artificial hip consists of a metal cup and a liner made of ceramic or polyethylene
6. Reaming the femoral shaft for the stem position
7. The new shaft with the head
8. Implantation of the new prosthesis together with the femoral head
9. Postoperative X-ray
Revision-Surgeries for Hips
Failed total hip surgeries can have different reasons. Causes for revisions are:
Due to these complications bone defects at the area of the prosthesis are possible.
These bone defects at the acetabular site are treated by using different cups, metal blocks in combination with screws and various kinds of cages in combination with a cup.
The most modern technique for big bone defects at the acetabular site is the use of individually made implants. Previous to the surgery, the bone defects are being analyzed with a computer tomogram. By the use of this computer tomogram a perfectly designed 3D model of the patient’s hip is created. This fits like a glove to the hand and has a perfect form-fit to the bone defect of the acetabulum.
Defects at the femoral shaft are covered by different lengths and designs of the stem prosthesis.
Artificial Knee Joint – Primary Total Knee Arthroplasty
Total knee replacements are performed in the standard procedure but can also be executed with modern techniques like patient specific cutting blocks. At the Orthopaedic Clinic Gersthof approximately 450 total knee replacements are performed yearly.
For the patient specific cutting blocks we use the VISIONAIRE technology. To be able to create such a patient specific cutting block, the patient needs previous to the surgery a x-ray of the whole limb and a magnetic resonance imaging (MRI) of the knee. The aim of this special technology is to reconstruct the bone axis in a 3 dimensional way and to find the adequate sizes and the position of the implants. Every individual cutting block fits perfect to the surface structure of the knee. Every cutting block has a cutting slot, in which the bone cut is performed. This method helps to create a stable and straight knee. In this way the knee prosthesis can be implanted perfectly.
Primary knee implantation in case of severe deformities
Revision-Surgeries for Knees
Failed total knee arthroplasties can have many reasons. Some of those are:
Shaky and instable knee joints
Aseptic loosening of the knee prosthesis
Bone fracture at the implant area (e.g. after accident)
Knee stiffness after total knee arthroplasty
Metal allergies etc.
If some of these above mentioned problems occur, a revision surgery is necessary. The following surgical factors have to be considered:
Bypassing of possible bone defects
Obtaining the correct and stable knee joint in flexion and extension
Adequate fixation of the prosthesis with stemmed implants
Images of a Revision surgery of the knee
The preoperative X-ray prior to the revision shows a cement spacer – implanted for a period of 3 months for healing the deep periprosthetic joint infection
X-ray after revision surgery
Video showing the successful result
Different metal augments in combination with a prosthesis are used for bypassing various bone defects. The status of the ligament stability of the knee leads the surgeon to use different degrees of the couple mechanism of the prosthesis. Theat means that the connection of the femoral prosthesis and the lower leg prosthesis (inlay and tibia prosthesis) can be different and is adjusted to preserve a stable knee.