Navigated open-wedge high tibial osteotomy: advantages and disadvantages compared to the conventional technique in a cadaver study

Abstract

High tibial osteotomy (HTO) is an established therapy for the treatment of symptomatic varus malaligned knees. A main reason for disappointing clinical results after HTO is the under- and overcorrection of the mechanical axis due to insufficient intraoperative visualisation. Twenty legs of fresh human cadaver were randomly assigned to navigated open-wedge HTO (n=10) or conventional HTO using the cable method (n=10). Regardless of the pre-existing alignment, the aim of all operations was to align the mechanical axis to pass through 80% of the tibial plateau (beginning with 0% at the medial edge of the tibial plateau and ending with 100% at the lateral edge). This overcorrection was chosen to ensure a sufficient amount of correction. Thus, the medial proximal tibia angle (MPTA) increased by 9.1+/-2.9 degrees (range 5.2 degrees -12.3 degrees ) on the average after navigated HTO and by 8.9+/-2.9 degrees (range 4.7 degrees -12.6 degrees ) after conventional HTO. After stabilization with a fixed angle implant, the alignment was measured by CT. After navigated HTO, the mechanical axis passed the tibial plateau through 79.7% (range 75.5-85.8%). In contrast, after conventional HTO, the average intersection of the mechanical axis was at 72.1% (range 60.4-82.4%) (P=0.020). Additionally, the variability of the mean corrections was significantly lower in the navigated group (3.3% vs. 7.2%, P=0.012). Total fluoroscopic radiation time was significantly lower in the navigated group (P=0.038) whereas the mean dose area product was not significantly different (P=0.231). The time of the operative procedure was 23 min shorter after conventional HTO (P<0.001). Navigation systems provide intraoperative 3-dimensional real time control of the frontal, sagittal, and transverse axis and may increase the accuracy of open-wedge HTO. Future studies have to analyse the clinical effects of navigation on corrective osteotomies.

Opening wedge high tibial osteotomy: navigation system compared to the conventional technique in a controlled clinical study

“…The accuracy and reliability of navigated opening wedge HTO have been shown in cadaveric studies [13][14][15].…”

Current concepts and applications of computer navigation in orthopedic trauma surgery

“…• Navigated high tibial osteotomy, including navigation of the osteotomy and determination of the mechanical leg axis [21][22][23].…”

Complications of closing wedge high tibial osteotomy

“…It affords real time data regarding mechanical axis and angular correction allowing the surgeon to control the correction more precisely. Several papers have looked at the accuracy of this technique and found it to be accurate, reliable and reproducible with a higher rate of precision in the corrections compared to conventional HTO [50][51][52]. Hankemeier et al [52] also showed less use of fluoroscopy and a shorter operative time with the use of navigation.…”

“…Several papers have looked at the accuracy of this technique and found it to be accurate, reliable and reproducible with a higher rate of precision in the corrections compared to conventional HTO [50][51][52]. Hankemeier et al [52] also showed less use of fluoroscopy and a shorter operative time with the use of navigation. Image-free navigation measurements in the coronal plane at present seem to be more accurate than in the sagittal plane, thus prompting Pearle et al [53] to recommend its use only in monitoring lower limb alignment in the coronal plane.…”