Experimental validation of the GNRB®for measuring anterior tibial translation.
The objective of this study was to validate the technique used to measure anterior tibial translation in cadaver knees using the GNRB®device by comparing it with the gold standard, the OrthoPilot®navigation system.



Simultaneous measurement of anterior tibial translation by the GNRB®and the OrthoPilot®in the chosen experimental conditions will result in significant differences between devices.



Five fresh frozen cadavers were used. The knee was placed in 20° flexion. Four calibrated posterior-anterior forces (134N to 250N) were applied. For each applied force, the anterior tibial translation was measured simultaneously by both devices. Two conditions were analyzed: anterior cruciate ligament (ACL) intact and ACL transected. The primary criterion was anterior tibial translation at 250N. The measurements were compared using a paired Student's t-test and the correlation coefficient was calculated. Agreement between the two methods was determined using Bland-Altman plots. Consistency of the measurements was determined by calculating the intraclass correlation coefficient.



For all applied forces and ligament conditions, the mean difference between the GNRB®and the navigation system was 0.1±1.7mm (n.s). Out of the 80 measurements taken, the difference between devices was less than ±2mm in 66 cases (82%). There was a strong correlation, good agreement and high consistency between the two measurement methods.



The differences between the measurements taken by the GNRB®and the navigation system were small and likely have no clinical impact. We recommend using the GNRB®to evaluate anterior knee laxity.



II controlled laboratory study.
Centre de chirurgie orthopédique et de la main (CCOM), hôpitaux universitaires de Strasbourg, 10, avenue Baumann, 67400 Illkirch, France; Université de Strasbourg, 4, rue Blaise-Pascal, 67000 Strasbourg, France. Electronic address: jean-yves.jenny@chru-strasbourg.fr.
J-Y
JY
Jenny
Centre de chirurgie orthopédique et de la main (CCOM), hôpitaux universitaires de Strasbourg, 10, avenue Baumann, 67400 Illkirch, France.
B
B
Puliero
B-Braun medical France, 204, avenue du Maréchal-Juin, 92100 Boulogne-Billancourt, France.
G
G
Schockmel
Genourob, rue de la Gaucherie, 53000 Laval, France.
S
S
Harnoist
Centre de chirurgie orthopédique et de la main (CCOM), hôpitaux universitaires de Strasbourg, 10, avenue Baumann, 67400 Illkirch, France; Institut d'anatomie normale, université de Strasbourg, 1, place de l'Hôpital, 67000 Strasbourg, France.
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P
Clavert
D000368:Aged; D000369:Aged, 80 and over; D000070598:Anterior Cruciate Ligament Injuries / Q000503:physiopathology; D053587:Arthrometry, Articular / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D002102:Cadaver; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013977:Tibia
Anterior tibial translation; GNRB; Knee; Measurements; Navigation system