2015 ISAKOS Biennial Congress ePoster #1717

High Tibial Osteotomy – Radiographic Analysis Comparing Navigated and Conventional Techniques

Timothy S. Whitehead, MBBS, FRACS, Richmond, VIC AUSTRALIA
Jeremy Stanley, BHB, MBChB, FRACS, Auckland NEW ZEALAND
Anneka K. Richmond, BSc (Hons), Melbourne, VIC AUSTRALIA
Patricia Seccombe, BPth, Melbourne AUSTRALIA
Kerian Robinson, MBBS, Melbourne AUSTRALIA
Kate E. Webster, PhD, Melbourne, VIC AUSTRALIA
Julian A. Feller, FRACS, Melbourne, VIC AUSTRALIA

OrthoSport Victoria, Epworth Richmond, Melbourne, Victoria, AUSTRALIA

FDA Status Not Applicable

Summary: Navigation during opening wedge HTO may have an important role in correcting larger deformities.

Rate:

Abstract:

Introduction

Medial opening wedge high tibial osteotomy (HTO) is a widely accepted procedure for the treatment of medial compartment osteoarthritis and varus malalignment. Successful clinical outcomes are dependent on accurate surgical technique and adequate correction of alignment. Navigation has been utilised recently to determine both pre operative alignment and post osteotomy correction.

Aim

Compared to traditional radiographic methods, it is hypothesised that navigation will produce more accurate and precise correction of alignment as measured on post-operative radiographs.

Materials And Methods

At a minimum follow up of 12 months, a consecutive series of 111 (117 knees) patients having undergone an opening wedge HTO had long leg AP radiographs in double-limb stance performed and analysed by 2 independent observers. Group A consisted of 61 patients (65 knees) who underwent a conventional procedure, whereas group B consisted of 50 patients (52 knees) where navigation was used during the procedure. The weight bearing line (WBL) and its percentage distance from the medial border of the tibia were calculated from pre and post-operative radiographs.

Results.
There were no differences between the groups with regard patient demographics and pre operative deformity. Both groups demonstrated mean post-operative corrections that were close to the target WBL % of 58% (group A – 56%, group B – 59%, p-0.183). However, when considering the spread of results (WBL within 5% of 58%), 71% of the navigated group as compared to 63% of the conventional group were able to achieve this. Patients with larger pre-operative deformity (>7degrees of varus) demonstrated more accurate post-operative correction in the navigated group (mean WBL 57% compared to 49%) and had a tighter spread of results within 5% of the WBL 58% target point (effect size – 0.15).

Conclusion

Although both surgical techniques demonstrated similar overall radiographic results, there was a significant difference in post-operative correction of more severe deformity in favour of the navigated technique. This suggests that navigation may have a particular role in this setting.