Quantitative analysis of the measuring capabilities of the KT-1000 knee ligament arthrometer.
The KT-1000 arthrometer was evaluated in vitro and in vivo to determine accuracy and quantify effects of potential error sources in clinical application. The KT-1000 arthrometer in vitro accuracy was evaluated by making 30 measurements of 13 known displacements (range, +15 to -15 mm). The effect of applied force on malalignment measurements was evaluated in vitro by making repeated measurements with force applied 5 degrees, 10 degrees, and 15 degrees from the vertical position. The effect of malpositioning the device along the joint line was evaluated in vivo by making repeated measurements 1 cm proximal and 1 cm distal to the joint line. The KT-1000 arthrometer was accurate in vitro (average error, 0.13 mm; SD, 0.12 mm). The range of measurements increased when the angle of force application was increased. Positioning the device 1 cm proximal to the joint line produced larger anterior translation measurements in vivo than those at the joint line (5.8 versus 5.4 mm), while positioning it 1 cm distal produced smaller measurements (4.4 mm). The KT-1000 arthrometer's accuracy indicates great potential for clinical application, but one must ensure that the displacing force is directed properly and the device is positioned accurately over the joint line.
Kowalk
D L
DL
MedSport, Orthopaedic Surgery, University of Michigan Medical Center, Ann Arbor 48106-0363.
Wojtys
E M
EM
Disher
J
J
Loubert
P
P
D004867:Equipment Design; D005069:Evaluation Studies as Topic; D006801:Humans; D007592:Joint Diseases / Q000473:pathology / Q000503:physiopathology; D007719:Knee Joint / Q000033:anatomy & histology / Q000502:physiology*; D008023:Ligaments, Articular / Q000502:physiology*; D009983:Orthopedic Equipment; D010329:Patella / Q000033:anatomy & histology; D016059:Range of Motion, Articular / Q000502:physiology*; D015203:Reproducibility of Results; D013977:Tibia / Q000033:anatomy & histology