Plate-Controlled Correction of Sagittal Plane Knee Deformities: The Entire-Segment Rotation Technique for Correcting Varus and Posterior Tibial Slope

Abstract

Sagittal-plane deformity around the knee is usually overlooked. Correction of the sagittal plane may be performed alone or simultaneously with coronal plane correction. This proposed technique ensures an effective rotational control of the proximal tibial fragment along with precise intraoperative correction of the posterior tibial slope in degrees instead of millimeters, exactly as it was preplanned in degrees.

Fig 1

Long-leg weight-bearing film of left leg showing the method of calculation of the posterior tibial slope.

Fig 2

Long-leg film of left lower limb for calculation of the frontal plane deformity.

Fig 3

The angle of posterior tibial slope correction (red triangle) between the anterior (line 1) and posterior (line 2) lines on the medial aspect of left tibia saw bone.

Fig 4

(A) The plate is fixed to proximal fragment parallel to the anterior line. (B) The entire proximal fragment is rotated until the anterior edge of the plate is parallel to the posterior line on the medial aspect of left tibia saw bone.

Fig 5

Custom-designed metal re-sterilizable goniometer.

Fig 6

Biplanar limb up high tibial osteotomy in left leg with the lamina spreader placed posteriorly to maintain posterior gap opening (head of the patient is oriented towards the left side of the image).

Fig 7

The use of a sterilized metal goniometer to draw the 2 lines of the posterior slope correction on the medial cortex of the upper left tibia (head of the patient towards the left side of the image).

Fig 8

the plate is fixed to the proximal fragment of left tibia in a way that makes its anterior edge against the anteriorly drawn line (line 1) (the head of the patient is oriented toward the left side of the image)

Fig 9

Using a bone-holding clamp to bring the anterior edge of the plate against the posteriorly drawn line over the proximal left tibia (line 2) (the head of the patient is oriented toward the left side of the image).

Fig 10

Fixing the distal fragment of left tibia to the plate after achieving the desired correction. (the head of the patient is oriented toward the left side of the image)

Fig 11

Check fluoroscopy views are then taken to ensure the achievement of the desired correction of left tibial deformity in both planes frontal (A) and sagittal (B).

Fig 12

Steps of correction of the posterior tibial slope of the proximal tibia. (A) The angle of correction; (B) the anterior and posterior lines representing the angle of correction by the plate; and (C) correction of the slope by moving the plate from anterior to posterior line.

Fig 13

Correction of right distal femur procurvatum osteotomy. (A) Closing-wedge anterior distal femur osteotomy with plate fixed to distal fragment only. (B) Angle of correction is determined intraoperatively in degrees. (C) The hinge is weakened by K wires. (D) A plate holding forces is used to move the plate to the desired angle of correction. (E) The anterior osteotomy is closed. (F) Fixing the proximal part of the plate after achieving the desired correction in the sagittal plane (the head of the patient is oriented toward the left side of the image).

Fig 14

(A) Preoperative procurvatum deformity in the right distal femur. (B) Long sagittal film showing the procurvatum deformity. (C-D) Postoperative alignment after achieving the desired alignment.

Fig 15

Steps of correction of the procurvatum deformity of the distal femur. (A) The angle of correction; (B) the anterior and posterior lines representing the angle of correction by the plate; and (C) correction of the slope by moving the plate from anterior to posterior line.