Analysis of deformity and preoperative planning for an osteotomy around the knee@@@Analyse der Deformität und präoperative Planung einer knienahen Osteotomie

Tibial displacement osteotomies are widely used in the treatment of medial compartment osteoarthritis. The ideal patient is active, younger than 55 years of age, and presents with unicompartmental arthrosis with stable ligaments and genu varum < 10 degrees. Careful preoperative planning for a high tibial osteotomy is essential to achieve the desired correction angle. The methods recommended for preoperative planning vary between simply assessment of the correction angle, planning diagrams drawn on X-rays, and use of digital radiological measuring devices. The mechanical axis of the leg should be displaced from the medial compartment that exhibits decreased height and signs of wear to the intact lateral compartment. The success of high tibial osteotomy depends to a large extent on accurate evaluation of the axial deviation and precise correction of the leg axis. This requires detailed knowledge of physiological axial relationships. Various planning methods are presented which are intended to increase the reliability of a tibial displacement osteotomy.