Reliability of a navigation system for intra-operative evaluation of antero-posterior knee joint laxity.
BACKGROUND
The purpose of this study was to investigate about the reliability of measuring antero-posterior laxity within-subjects for in-vivo studies using a navigation system.


METHODS
The analysis was performed by enroling 60 patients undergoing anterior cruciate ligament ACL reconstruction, and assessing AP laxity during the Lachman and drawer tests.


RESULTS
For the navigation system standard deviation for intra-trial measures was 0.7 mm, thus the intra-trial repeatability coefficient was 2.2 mm; standard deviation for intra-trial measure was 1.2 mm, while the reference inter-trial repeatability coefficient between expert surgeons was 3.4 mm.


CONCLUSIONS
In conclusion, this study suggests that KIN-Nav may represent a new method to measure and document AP laxity intra-operatively with improved accuracy and test the effect of surgical treatment in-vivo with higher sensitivity than in the past and this study quantify its reliability for within-subjects studies performed by a single expert surgeon.
Lopomo
Nicola
N
Istituto Ortopedico Rizzoli, Laboratorio di Biomeccanica, via di Barbiano, 1/10, Bologna BO 40136, Italy. n.lopomo@biomec.ior.it
Bignozzi
Simone
S
Martelli
Sandra
S
Zaffagnini
Stefano
S
Iacono
Francesco
F
Visani
Andrea
A
Marcacci
Maurilio
M
D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000503:physiopathology / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D004867:Equipment Design; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis / Q000503:physiopathology*; D007719:Knee Joint / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D019651:Plastic Surgery Procedures / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012371:Robotics / Q000295:instrumentation* / Q000379:methods; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D013673:Technology Assessment, Biomedical