Osteotomies around the Knee
There has been a revival in the indications and surgical techniques for osteotomies around the knee. The aim of an osteotomy is to redistribute pressure across the joint either to treat articular cartilage damage or early osteoarthritis and thereby reduce pain and delay eventual joint replacement. In certain scenarios of ligament instability a secondary improvement in stability could be achieved by altering tibial slope. Newer methods of fixation has improved the rehabilitation programmes and hence outcomes following osteotomies.
Coventry used full length weight-bearing radiographs on a series of 120 normal subjects of different gender and age and showed that thetibiofemoral mechanical angle was 1.2 degrees varus. The distal femoral anatomic valgus (measured from the lower one-half of the femur) was 4.2 degrees in reference to its mechanical axis. This angle became 4.9 degrees when the full-length femoral anatomic axis was used. When simulating a one-legged weight-bearing stance by shifting the upper-body gravity closer to the knee joint, 75% of the knee joint load passed through the medial tibial plateau.