A double-blind randomized controlled trial of total knee replacement using patient-specific cutting block instrumentation versus standard instrumentation

A double-blind randomized controlled trial of total knee replacement using patient-specific cutting block instrumentation versus standard instrumentation

Can J Surg 2019;62(6):460-467 | PDF | Appendix

Thomas R. Turgeon, MD, MPH; Brett Cameron, MD; Colin D. Burnell, MD; David R. Hedden, MD; Eric R. Bohm, MD, MSc

Abstract

Background: Patient-specific cutting blocks in total knee arthroplasty have been promoted to improve mechanical alignment, reduce alignment outliers and improve patient outcomes. The aim of this study was to compare the efficacy of patient-specific instrumentation (PSI) and conventional instrumentation (CI) in achieving neutral alignment and accurate component positioning in total knee arthroplasty.

Methods: We conducted a double-blinded randomized controlled trial in which patients were randomly assigned to treatment with either PSI or CI.

Results: Fifty-four patients were included in the study. No relevant improvement in coronal alignment was found between the PSI and CI groups with post-hoc power of 0.91. Tibial slope was found to be more accurately reproduced to the preoperative target of 3° with PSI than with CI (3.8°± 3.1° v. 7.7°± 3.6°, respectively, p < 0.001). There were no differences found in patient-reported outcome measures, surgical time or length of hospital stay.

Conclusion: Given the added cost of the PSI technique, its use is difficult to justify given the small improvement in only a single alignment parameter.

Clinical trial registration: Clinicaltrials.gov, no. NCT03416946

Résumé

Contexte : L’utilisation de guides de coupe sur mesure dans l’arthroplastie totale du genou a été recommandée pour améliorer l’alignement mécanique, réduire les alignements extrêmes et améliorer les résultats des patients. Cette étude cherchait à comparer la capacité des instruments sur mesure et des instruments classiques à engendrer un alignement neutre et un bon positionnement des composants dans le cadre d’une arthroplastie totale du genou.

Méthodes : Nous avons mené un essai clinique randomisé à double insu. Les patients étaient répartis aléatoirement entre le groupe de traitement avec instruments sur mesure et le groupe de traitement avec instruments classiques.

Résultats : Cinquante-quatre patients ont participé à l’étude. Aucune différence notable de l’alignement coronal entre les groupes n’a été relevée, pour une puissance observée de 0,91. La pente tibiale correspondait plus exactement à la cible préopératoire de 3° avec les instruments sur mesure qu’avec les instruments classiques (3,8° ± 3,1° contre 7,7° ± 3,6°, respectivement; p < 0,001). Il n’y avait aucune différence dans les mesures déclarées par les patients, la durée de l’intervention et la durée d’hospitalisation.

Conclusion : Étant donné l’amélioration minime d’un seul paramètre d’alignement et le coût supérieur de la technique sur mesure, son utilisation est difficile à justifier.

Enregistrement de l’essai : Clinicaltrials.gov, no NCT03416946.


Accepted May 6, 2019

Affiliations: From the Department of Surgery, Section of Orthopaedics, Max Rady College of Medicine, University of Manitoba, Winnipeg, Man. (Turgeon, Burnell, Hedden, Bohm); the Concordia Joint Replacement Group, Winnipeg, Man. (Turgeon, Burnell, Hedden, Bohm); and the Max Rady College of Medicine, University of Manitoba, Winnipeg, Man. (Cameron).

Acknowledgements: The authors acknowledge Sarah Tran and Trevor Gascoyne of the Orthopaedic Innovation Centre, Winnipeg, Man., for their assistance in executing this study. The authors also acknowledge Smith & Nephew for the in-kind donation of the Visionaire cutting blocks used in this study.

Competing interests: T. Turgeon and D. Hedden are consultants with Smith & Nephew. Smith & Nephew supplied the cutting blocks used in the study. No other competing interests were declared.

Contributors: T. Turgeon, C. Burnell, D. Hedden and E. Bohm designed the study. T. Turgeon, C. Burnell and D. Hedden acquired the data, which T. Turgeon and B. Cameron analyzed. T. Turgeon and B. Cameron wrote the article, which all authors reviewed and approved for publication. All authors agreed to be accountable for all aspects of the work.

DOI: 10.1503/cjs.018318

Correspondence to: T.R. Turgeon, Concordia Joint Replacement Group, 310-1155 Concordia Ave, Winnipeg MB R2K 2M9, tturgeon@cjrg.ca