Inverted V-Shaped High Tibial Osteotomy for Medial Osteoarthritic Knees With Severe Varus Deformity

Abstract

A hemi-closing-wedge and hemi-opening-wedge, inverted V-shaped high tibial osteotomy with local bone graft has been reported to be an effective surgical procedure for medial osteoarthritis of the knee. In this procedure, an inverted V-shaped osteotomy is made and a thin wedged bone block is resected from the lateral side and implanted in the medial opening space created after valgus correction. This procedure can provide sufficient valgus correction of the knee with severe varus deformity more easily than can closing-wedge high tibial osteotomy. The inverted V-shaped osteotomy does not change the posterior tibial slope, the patellar height, or the length of the lower limb at all because the center of tibial alignment correction by the inverted V-shaped osteotomy is located near the center of rotation of angulation of the lower-limb deformity. We recently modified this procedure by performing biplanar osteotomy, developing useful cutting guides, and fixing the tibia with a lateral locking compression plate. The surgical technique is described to enable the reproducible creation of the hemi-closing-wedge and hemi-opening-wedge, inverted V-shaped osteotomy with the locking plate for medial osteoarthritic knees with moderate or severe varus deformity.

Fig 1

Preoperative planning with an appropriate correction angle of the tibia is made using a standing, full-length right lower-limb anteroposterior radiograph. The hip-knee-ankle angle (HKA) (A), anatomic femorotibial angle (FTA) (B), and mechanical lateral-distal femoral angle (mLDFA) and medial-proximal tibial angle (MPTA) (C) are measured to identify the origin of the limb deformity and clarify where the genu varum is formed in the lower limb. (D) The weight-bearing line (WBL)—a straight line from the center of the femoral head to the center of the talar dome—is drawn. To evaluate the degree of alignment deformity of the knee, the point at which the mechanical axis passes across the tibial plateau is determined, and the percentage of this point on the tibial plateau is calculated, with the medial edge defined as 0% and the lateral edge defined as 100%.

Fig 2

(A) Inverted V–shaped osteotomy lines are drawn on the full-length right lower-limb radiograph so that the apex point (point P) is located at the center of the tibial condyle and approximately 3 cm to the joint surface line and the apex angle is approximately 110°. To calculate an appropriate angle of the lateral hemi-wedge resection, a long line (line A) is drawn from the center of the femoral head through the 65% point on the lateral tibial plateau. Then, another line (line B) is drawn from the apex point (point P) to the center of the talar dome, and the length of line B is measured. An arc (arc C), the center and the radius of which are the apex point (point P) and line B, respectively, is drawn across line A. Another line (line D) is drawn from the apex point (point P) to the crossing point between line A and arc C. The angle (α) formed between lines B and D provides the lateral hemi-wedge resection angle, which is identical to the correction angle of the lower-limb alignment. (B) A lateral hemi-wedge resection line (dashed line) is drawn using the α angle.

Fig 3

(A) An anterolateral curved skin incision is made on a right knee beginning at the Gerdy tubercle (G). (B) A 2-cm longitudinal incision is made on the lateral patellar retinaculum followed by the medial patellar retinaculum, along the lateral edge of the patellar tendon, starting from the tendon attachment portion to the tibial tubercle in the proximal direction.

Fig 4

A lateral locking compression plate (TomoFix Lateral High Tibia Plate) is prepared for the right (R) tibia, and sleeves for drilling are attached at holes E and C in the plate. The surgeon holds the plate, places it on the lateral aspect of the tibia, and determines an appropriate location for the proximal edge of the plate so that hole E is located at a level beneath the subchondral bone of the tibial plateau, observing the positional relation between the plate and the tibia with a C-arm fluoroscope. The location of hole C is then marked on the lateral aspect of the tibia with ink.

Fig 5

(A) Observing the right tibia with a fluoroscope, the surgeon determines the apex point of the inverted V–shaped osteotomy (ie, apex wire) using a lateral locking plate, which is located at the center of the tibial condyle width and approximately 3 cm distal to the joint surface line. (B) The apex point is located approximately at the point where the medial edge of the patellar tendon is attached to the tibial tubercle. Under fluoroscopic control, a Kirschner wire is inserted at this point in the anteroposterior direction.

Fig 6

(A) The protractor-installed Wedge Cutting Guide is attached to the apex wire in the right tibia. (B) With this guide, 2 pairs of Kirschner wires (K-wires) can be inserted into the tibia through the parallel sleeves so that each inserted K-wire precisely reaches the apex wire. Through a pair of sleeves in this guide, the first pair of K-wires is inserted into the tibia toward the apex wire so that the lateral osteotomy line passes through a point 5 mm distal to the marked hole C point. Then, the other pair of sleeves is set distally at the planned angle with the installed protractor, and 2 K-wires are inserted into the tibia at a location more distal to the first pair toward the apex wire.

Fig 7

(A) A V-shaped Parallel Drill Guide, in which 2-mm-wide tunnels are aligned in parallel with a center-to-center distance of 3 mm, is attached to the apex wire in the right tibia. The apex angle of this V-shaped guide is changeable by the surgeon, measuring with the installed protractor. Commonly, the apex angle of the guide is set at 110°. (B) The lateral side of the V-shaped Parallel Drill Guide is fixed on the lateral osteotomy line. (C) The medial side of this guide is fixed on the medial aspect of the tibia by inserting a 2-mm Kirschner wire into the most medial hole. A total of 7 to 10 parallel holes are drilled into the tibia along the medial osteotomy line using a different 2-mm-thick Kirschner wire.

Fig 8

A coronal ascending osteotomy parallel to the anterior surface of the right tibial tubercle is made with a thin oscillating saw (Hall Instruments), leaving the tibial tubercle intact with a width of 10 mm.

Fig 9

(A) A lateral hemi-wedge bone resection is performed along the 2 pairs of guidewires previously inserted in the right tibia. (B) After a radiolucent retractor is inserted between the tibia and the detached posterolateral structures, only the lateral cortex is cut with a thin oscillating saw. The resected bone wedge and the additionally trimmed bone chips are kept moist for grafting of the medial opening space later.

Fig 10

The medial side of the right tibia undergoes osteotomy with a thin chisel along the previously drilled thin parallel holes (A), leaving a 5-mm bony bridge at the apex portion intact (B).

Fig 11

(A) The surgeon performs valgus correction of the right tibia by manually applying a valgus force to the knee and confirms that the created lateral hemi-wedge space is completely closed. The assistant surgeon temporarily fixes the proximal and distal parts of the right tibia by inserting 2 crossing Kirschner wires (K-wires) into the tibia. (B) Fluoroscopic evaluation is performed using a long, straight metal rod, which is placed above the centers of the hip and ankle joints. The surgeon confirms that the mechanical axis of the corrected knee passes through the Fujisawa point (65%) on the tibial plateau.

Fig 12

(A) The TomoFix Lateral High Tibia Plate, on which 4.3-mm Threaded LCP Drill guides are attached to hole E followed by hole 2, is again placed on the lateral side of the right tibia. (B) With observation of the fluoroscopic image, a 2-mm Kirschner wire is inserted through the 2-mm TomoFix Guide Sleeve attached to hole E into the proximal tibia at a sufficiently proximal level, parallel to the joint line.

Fig 13

To apply a compression force to the post-osteotomy surface, a bicortical drill hole is created through combination hole 1 (Combi-hole 1) with a 3.2-mm drill sleeve, and a 4.5-mm cortical screw is inserted without applying a compression force on the right tibia.

Fig 14

(A) The cortical screw inserted into combination hole 1 is removed, and a 5.0-mm locking head screw undergoes bicortical insertion into the combination hole in the same manner in the right tibia. (B) The resected bone block is implanted in the medial opening space created after plate fixation.

Fig 15

Closure is completed with absorbable sutures in layers in a right knee.

Fig 16

Preoperative and postoperative plain radiographs in a right knee (R): preoperative anteroposterior (A) and lateral (B) views and postoperative anteroposterior (C) and lateral (D) views.