High Tibial Osteotomy With Miniaci Planning Using Manual and Semiautomated Digital Measures.

BACKGROUND

Inadequate deformity analysis and planning before high tibial osteotomy (HTO) may result in correction errors with unsatisfactory clinical results.

INDICATIONS

The purpose of this article is to describe the deformity analysis and preoperative planning before HTO. This surgery is effective for young patients with compartmental mild knee osteoarthritis. A partial deformity analysis without considering the femoral or intra-articular deformity may lead to overcorrection or excessive joint line obliquity. Preoperative planning using the Miniaci method with manual or semiautomated digital measures may help to prevent these types of errors.

TECHNIQUE DESCRIPTION

Landmarks are used at the proximal femoral side, distal condyles, proximal tibial plateau, and talus borders to define angles automatically on PeekMed software. Fujisawa point is determined to be 50% of the length of the proximal tibia, and Miniaci method is performed after defining the weightbearing line. The method can be performed manually or semiautomatically with the software. In this last case, the optimal procedure to be done to correct the malalignment is proposed by the software which automatically does the opening of the osteotomy to match the desired weightbearing axis and displays the size of the wedge in millimeters.

RESULTS

The intraobserver and interobserver reproducibility were performed by 2 different analyses and 2 different observers. The precision of the measures was confirmed based on computed tomographic (CT) scan 3-dimensional measures defined as the gold standard. All the intraobserver and interobserver reproducibility correlation coefficients and precision were satisfactory compared with the gold standard. Hip-knee-ankle angle may vary because of weightbearing situations between CT and long-axis x-rays.

DISCUSSION/CONCLUSION: The interest of semiautomated software for angular value measurements is now well recognized, and the inclusion of anatomical landmarks allows accurate and reproducible angular value measurements. Automatic knee osteotomy planning analyzes the metaphyseal deformity of both the tibia and the femur, and the software suggests the optimal procedure with the degree of openness to obtain the desired mechanical axis without creating excessive joint line obliquity.