[Periarticular knee osteotomies for pre-arthritic deformities in the frontal plane : Indications and surgical techniques].

Background: Currently, periarticular knee joint osteotomies are an integral part of the treatment of early arthritic deformities in the knee joint.

Diagnostics: Analysis of the deformity is performed with a standardized full-leg standing x‑ray of both legs, as well as a lateral x‑ray of the knee joint that includes 2/3 of the proximal tibial shaft. An MRI examination of the knee joint is obtained to assess the articular cartilage, the ligaments and menisci. Torsion angle measurements with the CT/MRT supplement the diagnostics if necessary. Knowledge of normal physiological values and their standard deviations of the mechanical leg axis and the joint angles around the knee is obligatory.

Therapy: The osteotomy is performed as close as possible to the femoral and/or tibial deformity. Postsurgical deformities including pathological patella position or a significant difference in leg length must be prevented. A description of proximal tibia opening or closing wedge osteotomies based on the nomenclature of the joint angles by Paley is presented. The indications for the various osteotomy techniques in the coronary plane are discussed in detail.