Case Control Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Jan 18, 2016; 7(1): 61-68
Published online Jan 18, 2016. doi: 10.5312/wjo.v7.i1.61
Patient specific guides for total knee arthroplasty are ready for primetime
Martijn GM Schotanus, Bert Boonen, Nanne P Kort
Martijn GM Schotanus, Bert Boonen, Nanne P Kort, Department of Orthopaedic Surgery, Zuyderland Medical Centre, 6162 BG Sittard-Geleen, The Netherlands
Author contributions: Schotanus MGM designed the study, gathered and analysed all the data, wrote the initial draft of the manuscript, managed and performed the study; Boonen B ensured the accuracy of the data and the analysis and gave critical revisions related to important intellectual content of the manuscript; Kort NP designed the study, revised the manuscript and gave final approval of the version of the article to be published.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board (METC Atrium-Orbis-Zuyd, Heerlen, the Netherlands) file name 13-N-09.
Informed consent statement: All patients gave informed consent prior to the study enrolment.
Conflict-of-interest statement: Dr. Nanne P Kort is a consultant on the PSG technique for Biomet, Europe. The other authors declare that they have no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Martijn GM Schotanus, MSc, Research Manager, Department of Orthopaedic Surgery, Zuyderland Medical Centre, location Dr. H vd Hoffplein 1, 6162 BG Sittard-Geleen, The Netherlands.
Telephone: +31-88-4597433 Fax: +31-88-4597986
Received: February 11, 2015
Peer-review started: February 12, 2015
First decision: June 18, 2015
Revised: October 22, 2015
Accepted: November 17, 2015
Article in press: November 25, 2015
Published online: January 18, 2016

AIM: To present the radiological results of total knee arthroplasty (TKA) with use of patient specific matched guides (PSG) from different manufacturer in patients suffering from severe osteoarthritis of the knee joint.

METHODS: This study describes the results of 57 knees operated with 4 different PSG systems and a group operated with conventional instrumentation (n = 60) by a single surgeon. The PSG systems were compared with each other and subdivided into cut- and pin PSG. The biomechanical axis [hip-knee-ankle angle (HKA)], varus/valgus of the femur [frontal femoral component (FFC)] and tibia (frontal tibial component) component, flexion/extension of the femur [flexion/extension of the femur component (LFC)] and posterior slope of the tibia [lateral tibial component (LTC)] component were evaluated on long-leg standing and lateral X-rays. A percentage of > 3° deviation was seen as an outlier.

RESULTS: The inter class correlation coefficient (ICC) revealed that radiographic measurements between both assessors were reliable (ICC > 0.8). Fisher exact test was used to test differences of proportions. The percentage of outliers of the HKA-axis was comparable between both the PSG and conventional groups (12.28% vs 18.33%, P < 0.424) and the cut- and pin PSG groups (14.3% vs 10.3%, P < 1.00). The percentage of outliers of the FFC (0% vs 18.33%, P < 0.000), LFC (15.78% vs 58.33%, P < 0.000) and LTC (15.78% vs 41.67%, P < 0.033) were significant different in favour of the PSG group. There were no significant differences regarding the outliers between the individual PSG systems and the PSG group subdivided into cut- and pin PSG.

CONCLUSION: PSG for TKA show significant less outliers compared to the conventional technique. These single surgeon results suggest that PSG are ready for primetime.

Keywords: Total knee arthroplasty, Patient specific matched guides, Patient matched instruments, Single surgeon, Alignment, Conventional instruments, Cutting guides, Pin guides

Core tip: Total knee arthroplasty (TKA) is one of the most successful and commonly performed surgical procedure for the treatment of severe knee osteoarthritis with excellent 15-20 years survivorships. This article provides an analysis on patient specific matched guides (PSG) between different manufacturers and the conventional technique and between pin- and cutting guides for TKA. In addition, we compared our results with previous studies (level 1 evidence), which are generally unambiguous, and show no radiological difference. However, in this trial, we do see difference in favour of the PSG technique.