Realignment osteotomy (synonym: corrective osteotomy) is a surgical procedure in trauma surgery and orthopedics that is used as a therapeutic measure for existing joint damage in order to relieve the joint and reduce progression (advancement) of the damage. The principle of the treatment is based on the surgical compensation of the oblique leg axis, which, among other things, can cause valgus and varus at the knee joint and cause permanent overloading of the knee joint structures. During the surgical intervention, an osteotomy (surgical cutting of the bone) is performed so that it is possible to restore the original anatomical shape. This surgical intervention is of particular importance in the treatment of knee joint arthrosis, as the osteotomy close to the joint allows relevant relief of the degeneratively altered joint (signs of wear and tear). The primary field of application of the realignment osteotomy is the treatment of knee joint arthrosis, but it should be noted that this surgical procedure can be applied to all bones, so that the possibilities of use are hardly limited. To increase bone and joint stability, osteotomy should be performed on the metaphysis (section of bone relevant to length growth) of a long bone.
Indications (areas of application)
Genu varum (“bow legs”).
One speaks of a genu varum when, at the knee joint, the medial angle (located toward the center of the body) is smaller than the norm. In the knee joint, this represents an angle smaller than approximately 186°. Because of the greater distance between the two hip joints compared to the distance between the knee and the ankle, a minor deformity is normal. Smaller deformities usually heal in the course of growth even without treatment. In the case of significantly larger deviations from the given norm, it is important that surgical intervention is performed quickly so that uneven loading of the two partial joints of the knee joint can be prevented, which, among other things, can prevent premature wear. Many knee arthroses in older people are due to bow legs. A common cause of genu varum before vitamin D prophylaxis was established was early childhood vitamin D deficiency, also known as rickets.
- Primary varus – the present genu varum type is a congenital unilateral overload of the knee joint. This congenital deformity (congenital deformity) is accompanied by non-physiological loading, so surgery may be necessary.
- Double varus – this form of genu varum represents a deformity characterized by both increased loading on the inner surface of the knee joint and associated with an increase in traction forces on the outer surface of the knee joint. The existing deformity is due to two causes: the incorrect position of the tibia to the femur (joint connection between the upper and lower leg) and damage to the ligamentous structures of the knee joint.
- Triple varus – in this case, there is a prolonged instability of the knee joint due to an existing genu varum, which leads to a permanent unilateral joint load. In addition to the symptoms of the double varus, a relevantly increased external rotation of the tibia to the femur is recognizable in the triple varus. Furthermore, the extension capacity increases compared to the healthy knee joint. The load line shifts further medially out of the joint and thus approaches the opposite knee. Nevertheless, with this symptomatology, a lesion of the posterior or anterior cruciate ligament must also be considered, since these pathological changes are also accompanied by hyperextension (increased extension). Based on this, it is necessary that the optimal treatment of varus deformity also includes the therapy of accompanying instabilities of the ligamentous apparatus of the knee joint.
Contraindications
- Prolonged blood clotting – taking substances that result in prolonged blood clotting must be stopped before surgery. With the help of blood tests, it is possible to check the blood clotting characteristics and allow the patient to undergo surgery.
- Osteoporosis – in the presence of this disease, the surgeon must decide whether it is reasonable to perform the operation anyway.
Before surgery
- Because the procedure is an invasive surgical intervention, optimal preparation of the patient is necessary. This includes, among other things, attention to the medications to be taken on the patient’s side, which, if not discontinued, can make the procedure too risky. An example of such a group of medications would be anticoagulants (anticoagulants) such as acetylsalicylic acid (ASA) or clopidogrel, which significantly prolong bleeding time when taken. Discontinuation of such substances must be done only on medical advice.
- From an infectious disease point of view, it is considered particularly important to minimize the time the patient is lying down before surgery to minimize the risk of infection.
The surgical procedure
To surgically treat knee joint osteoarthritis with an adjustment osteotomy, a special oscillating (swinging) saw is used at the beginning of the procedure to surgically cut through the bone, which was identified as the cause of the malalignment during the preliminary examinations performed. Therefore, either the tibia (shin bone) or the femur (thigh bone) can be cut to perform the osteotomy. Osteotomy makes it possible to counteract the progression of pre-existing articular cartilage wear by removing a bone wedge for axis correction. In order to achieve precise axis correction, the extent of the bone wedge must be precisely measured preoperatively (before the operation) using a planning sketch on the X-ray. After removal of the bone wedge, it is then possible to reunite the individual bone parts in the correct position. In order to be able to guarantee stability, staples, plates or screws are used to fix the bone parts. The gap in the bone created by the osteotomy is widened, if necessary, using a distractor to perform the necessary corrective measures. After correction of the axial malposition, osteosynthesis (bone augmentation) is subsequently performed to secure the achieved correction until bony healing. Here it is necessary to know that bone reconstruction takes place in several intermediate stages with varying degrees of stability. If this is not possible, there may be the option of filling the resulting gap with artificial bone replacement.
After the operation
Immediately following the procedure, controlled administration of analgesic substances is given. Furthermore, medication should be used to reduce the risk of thrombosis to prevent subsequent complications such as pulmonary embolism. After the hospitalization period, rehabilitation measures should be carried out directly. However, it should be noted that stress reduction should follow the procedure before the ligamentous apparatus and musculature can be strengthened again. To improve mobility, the musculature should be adapted to potential loads through moderate training.
Possible complications
Complications of an adjustment osteotomy are primarily due to preparation or surgical errors. To achieve an optimal outcome through surgery, a planning outline must be established based on the results of diagnostic imaging and patient history.
- Mobility limitations – osteotomy represents a complex surgical procedure in which the slightest deviation from the location of the bone transection can result in significant deterioration of mobility. The severing of nerve cords can also lead to paralysis, as there is no control over the innervated muscle groups.
- Infection – since the procedure is a relatively major surgical intervention, there is some risk of infection despite very good hospital hygiene.
- Anesthesia – the conversion osteotomy is performed under general anesthesia, which, among other things, may result in, for example, nausea and vomiting, tooth damage and possibly cardiac arrhythmias. Furthermore, in rare cases, circulatory instability may also be possible, which is a feared complication of general anesthesia, but now occurs relatively rarely as a complication. Overall, general anesthesia is nevertheless a low-complication anesthetic procedure.
