Curve-on-curve technique is more reliable than free-floating technique for tibial components positioning in posterior stabilized total knee arthroplasty using symmetrical tibial components in varus osteoarthritis.

INTRODUCTION

Malrotation of the tibial components in total knee arthroplasties is a common cause of pain and functional impairment. There are multiple methods used to establish the tibial component rotation, but there is still no consensus which method is the best.The objective of this study was to compare two of the most commonly used techniques, that is the use of self-alignment during passive range of motion (free-floating technique) versus the anterior cortex referencing method (Curve-on-curve technique).

MATERIALS AND METHODS

Twenty-eight consecutive patients with advanced varus-type osteoarthritis scheduled for posterior stabilized total knee replacement with symmetrical tibial baseplate were included in the study. We set the location of the tibial component trial using the method of self-alignment during passive range of motion and compared it to the location of the tibial component trial when referenced to the anterior cortex. The distance between the two locations was independently measured by two experienced surgeons.

RESULTS

In all of the cases, the tibial component centre was located more laterally on the anterior tibial cortex in the anterior cortex referencing technique when compared to the self-alignment technique [range 3-19 mm].

CONCLUSION

The tibial components placed using the anterior referencing technique (Curve-on-curve technique) are more externally rotated as compared to those placed using the self-alignment technique (free-floating technique) in posterior stabilized total knee arthroplasties using symmetrical tibial components.