High tibial osteotomy

Abstract

High tibial osteotomy (HTO) is a widely performed procedure to treat medial knee arthrosis. In general, published studies on HTO report good long-term results with a correct patient selection and a precise surgical technique. The ideal candidate for an HTO is a middle aged patient (60 to 65 years of age), with isolated medial osteoarthritis, with good range of motion and without ligamentous instability. Some issues that need resolution remain; these include the choice between opening and closing wedge tibial osteotomy, the graft selection in opening wedge osteotomies, the type of fixation, the comparison with unicompartmental knee arthroplasty and whether HTO significantly affects a subsequent total joint replacement. Precise indication, preoperative planning, and operative technique selection are essential to achieve good results.

Keywords: Closed wedge osteotomy; High tibial osteotomy; Opening wedge osteotomy; Osteoarthritis.

Fig. 1

A diagram of the alignment of the limb. Mechanical axis, anatomic axis and tibiofemoral angle.

Fig. 2

Anteroposterior weight-bearing radiographs are used in planning high tibial osteotomy. (A) Closing wedge. The weight-bearing line is determined by measuring from the point located at 62.5% of the width of the tibial plateau to the center of the femoral head and the center of the ankle. The angle (α) formed at the intersection of these weight bearing lines represents the angle of correction. The wedge bone that constitutes the α angle is to be removed. (B) Opening wedge. The α angle is calculated and transferred to the osteotomy site to open the proximal tibia.

Fig. 3

Opening wedge osteotomy. (A) A guide wire is placed from 3.5-4 cm below the medial joint line to about 1 cm below the lateral articular margin of the tibia. (B) Cortical osteotomy is performed with an oscillating saw inferior to the guide wire and an osteotome. (C) When the osteotomy is completed, the medial tibia is opened with a wedge.

Fig. 4

An image intensifier and an alignment rod are used to control proper coronal alignment during axial loading of the joint. (A) The center of the femoral head. (B) The point (located at 62.5% of the width of the tibial plateau) on the tibial plateau. (C) The center of the ankle.

Fig. 5

The level of the patella after closing and opening wedge high tibial osteotomy. (A) Preoperatively. (B) After closing wedge osteotomy, the segment between the tibial plateau and tibial tuberosity is shortened. (C) After opening wedge osteotomy, this segment is enlongated. Relative patella baja can occur.

Fig. 6

Change of the tibial slope after high tibial osteotomy. (A) Closing wedge high tibial osteotomy (HTO) can cause no change or a decrease in posterior tibial slope, and posterior translation of the tibia can be increased. (B) Opening wedge HTO usually can be caused an increase in posterior tibial slope, and anterior translation of the tibia can be increased.