Development of a simple device for measurement of rotational knee laxity.
The goal of this study was to develop a new device for the measurement of rotational knee laxity and to measure intra-observer and inter-observer reliability in a cadaveric study. An array of established tools was utilized to design the device with a basis that consists of an Aircast Foam Walkertrade mark boot. A load cell was attached to the boot with a handle bar for application of moments about the knee. An electromagnetic tracking system was used to record the motion of the tibia with respect to the femur. The total arc of motion ranged from 23 degrees at full extension to 46 degrees at 90 degrees of knee flexion. The intra-tester ICCs ranged from 0.94 to 0.99. The ICC for inter-tester reliability ranged from 0.95 to 0.99. In summary, the new device for measurement of rotational knee laxity is simple, reliable, and can be used in a non-invasive fashion in the office or surgical suite document clinical outcome in terms of rotational knee laxity.
Musahl
Volker
V
Department of Orthopaedic Surgery, University of Pittsburgh, 3471 Fifth Avenue, Pittsburgh, PA 15213, USA. musahlv@upmc.edu
Bell
Kevin M
KM
Tsai
Andrew G
AG
Costic
Ryan S
RS
Allaire
Robert
R
Zantop
Thore
T
Irrgang
James J
JJ
Fu
Freddie H
FH
D000368:Aged; D001696:Biomechanical Phenomena / Q000295:instrumentation; D002102:Cadaver; D055590:Electromagnetic Phenomena / Q000295:instrumentation; D004867:Equipment Design; D005269:Femur / Q000503:physiopathology; D006801:Humans; D007593:Joint Instability / Q000175:diagnosis*; D007719:Knee Joint / Q000503:physiopathology*; D015588:Observer Variation; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D012399:Rotation; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013977:Tibia / Q000503:physiopathology; D019415:Torque