Knee osteotomies

The procedure is performed in such a way as to correct the existing deformity and improve the mechanical loading of the joint. In addition, it may help relieve venous intraosseous congestion (bone edema).

Indications for osteotomy:

Axial deformities such as varus or valgus, as well as hyperextension or flexion contracture of the knee, may result from conditions such as growth disturbances, epiphyseal injuries, malunited fractures, or joint destruction caused by osteoarthritis or instability. In these cases, the operation aims not only to correct the deformity but also to prevent or delay the progression of osteoarthritis.

Osteoarthritis is often associated with varus deformity and overload of the medial compartment. It causes localized pain and destruction of the articular surfaces in at least one compartment. When this occurs in a relatively young patient, provided that the knee maintains a reasonable range of motion and stability, a high tibial valgus osteotomy offers a good alternative for unloading the joint. By correcting the mechanical axis of the knee, loads are shifted from the medial compartment toward the center or lateral side. Pain relief may also partly result from the decompression of vascular congestion in the subchondral bone (improvement of bone edema).

Technique:

A thorough preoperative plan is essential, with precise measurement of the angles and the site of the osteotomy. In a high tibial osteotomy, a fibular osteotomy at a lower level should also be performed.

The osteotomy can be carried out in two ways:

1. Resection of a wedge-shaped bone segment with the base laterally, performed above the insertion of the patellar tendon. The resulting wedge defect is stabilized with staples in the correct position, and the limb is then immobilized in a cast for four to six weeks.
2. Alternatively, a dome-shaped osteotomy can be performed above the tibial tuberosity, with the bone fragments stabilized in the desired position using compression pins.

Results: High tibial valgus osteotomy for osteoarthritis provides very good outcomes, provided the arthritis is limited to a single compartment, and the knee maintains a good range of motion and stability. These criteria must be strictly observed.

Complications: The main complication is failure to correct the deformity, usually due to poor surgical technique. In cases of medial compartment osteoarthritis, the result may be unsatisfactory unless a slight overcorrection into valgus is achieved.