Validation : Two experienced examiners used the GNRB and the KT1000 to record the anterior drawer translation of each knee on 20 students, aged 19 and 21 years and free of all ACL tear; in all, 680 measurements were taken. The translation and the translation differentials for two pressure levels, obtained with the GNRB and the KT1000 by the two examiners, out of 3 levels 67 N, 89 N or 134 N, were compared.

Student, Fisher and ANOVA tests were used.

1. Measurement variation was significantly lower with the GNRB, independent of the examiner and the level of pressure.

2. The reproducibility of the GNRB improved with the increase of pressure levels, compared to that of the KT1000.

3. The right / left differential shift at 134N was equal to 0.8 mm (IC95%: 0.7 –0.94) with the GNRB and 1.34 mm (IC 95%: 1.1 –1.56) with the KT1000 (p=0.001).

Conclusions : The GNRB affords a significantly higher degree of precision compared to that of the KT1000 and better inter-observer reproducibility

see publication in English downloading PDF

12 partial tears of the ACL confirmed by MRI, of which 6 were subsequently operated upon, were studied according to the same protocol. The study concerned 7 males and 5 females of an average age of 24 years (10 to 36 years).

The 163 extension measurements on the injured knees were compared to 162 measurements on healthy knees. ROC curves were used.

The threshold of 1.5 mm, giving a sensitivity of 76.5 % and a specificity of 94 %, was decided upon. The area under the curve is significantly greater (p = .0002) with the GNRB (.815) than with the KT-1000 (.638).

To our knowledge, no other author has measured the threshold of partial tears to 1.5 mm of precision with a specificity of 95%. All the patients operated upon presented tear of the anterior or posterior bundle and slackening of the other bundle.

We believe that the screening of partial tears is particularly important for early care, follow-up, and the waiting period to be respected before resuming the sports activity.

The rate of false negatives varies between 5 and 35%, according to those who think they know the rate. Certain studies have shown a rate of false negatives neighboring:

27% according to P. Djian (Congrès de la Société Française de Traumatologie du Sport , June 2004)

50% according to Isberg (Knee Surgery, Sports Traumatology, Arthroscopy, 2006)

69% of respondents declared that the marketing of a new solution to detect ACL injuries is of significant importance. The availability for sale of such a solution is even considered necessary in the short term by 60% of those surveyed.

Nevertheless, 82% of those surveyed had not yet heard of the GNRB project.