2017 ISAKOS Biennial Congress ePoster #1207

 

Alignment and Functional Results do not Improve with Patient-Specific Positioning Guides in Total Knee Replacement - A Prospective Multicenter Randomized Trial

Justin van Leeuwen, MD, Skien NORWAY
Stephan Maximilian Röhrl, MD, PhD, Oslo NORWAY

Oslo University Hospital (OUS), Oslo, NORWAY

FDA Status Cleared

Summary

This study has not shown better alignment and clinical results with the use of patient-specific positioning guides in total knee arthroplasty

Abstract

Introduction

Although the use of patient-pecific positioning guides (PSPGs) in total knee arthroplasty (TKA) in theory is promising, the technique has not yet proven its superiority compared to the conventional method.

Aim

The purpose of our study was to compare radiological alignment and clinical outcome between TKA performed with the use of PSPGs to the conventional operation method. Our null hypothesis was that the use of PSPGs would not lead to better alignment and better clinical results.

Patients and Methods
Three hospitals participated in a prospective trial where hundred-nine patients were randomized to either the conventional method or to the use of PSPGs in their treatment with TKAs. Postoperatively a full length standing anteroposterior radiograph and a CT scan were taken. The alignments were measured for both the femoral and tibial components in the frontal, sagittal and axial plane on the CT scans. The Knee Injury and Osteoarthritis Outcome Score (KOOS), the Eurocol-5D-3L (Eq5D) descriptive system and visual analogue scale (VAS), a pain score (NRS) and range of motion (ROM) were recorded pre-operatively, at 3 months, 1 and 2 years. The operation time and length of hospital stay were recorded.

Results

Ninety patients were available for postoperative CT measurements. A significant difference between the groups was found for the femoral component angle in the coronal plane (p=0.03, CI 0.08;1.69) and for the tibial component angles in the frontal (p=0.03 ,CI -1.98;-0.44) and the sagittal planes (p=0.01 ,CI -2.72;0.42). Less consistent alignment was found in the PSPG group for the femoral and tibial component angles in the frontal plane and more consistent in the tibial sagittal plane.
The Hip-Knee-Ankle angle, the KOOS sub scores, the Eq5D, pain (NRS), ROM, operation time and length of hospital stay were not significant between the 2 groups.

Conclusion

The study was not able to prove a clear benefit with regard to radiological alignment and/or clinical outcome after TKAs with the use of PSPGs at patients with primary gonarthritis.

Discussion

The use of PSPGs imply an extra cost due to a preoperative MRI. Above this the guides itself have an additional cost. As we were not able to prove a radiological and clinical benefit of the use of PSPGs we recommend the conventional operation method for TKA.