Ws. Queale et al., INSTRUMENTED EXAMINATION OF KNEE LAXITY IN PATIENTS WITH ANTERIOR CRUCIATE DEFICIENCY - A COMPARISON OF THE KT-2000, KNEE SIGNATURE SYSTEM,AND GENUCOM, The Journal of orthopaedic and sports physical therapy, 19(6), 1994, pp. 345-351
Knee ligament arthrometers are used during rehabilitation to assess ch
anges in knee laxity after anterior cruciate ligament injury. This stu
dy investigated the reliability and error associated with measurements
of knee laxity using three different instrumented devices: the KT-200
0, the Knee Signature System (KSS), and the Genucom Knee Analysis Syst
em to aid in the interpretation of instrumented laxity measurements du
ring rehabilitation. Ten subjects with unilateral anterior cruciate de
ficiency were examined by two testers on two separate days. Measuremen
t error was calculated as the minimum difference required to assume a
true change in laxity between two measurements (p < 0.05). Between-day
reliability was relatively high for both the KSS and the KT-2000 (.95
and .83, respectively) but substantially lower for the Genucom (.22).
Intertester reliability was slightly lower for the KT-2000 and the KS
S (.92 and.78, respectively) and slightly higher but still low for the
Genucom (.27). When monitoring changes in anterior laxity of an anter
ior-cruciate-deficient knee, the following error values were determine
d to be needed in order to assume a true difference between successive
measurements: KT-2000, 2.0 mm, KSS, 4.2 mm; and Genucom, 5.9 mm. The
results of this study suggest that measurements of anterior laxity tak
en by a single examiner using the KT-2000 provide the most reliable me
asurements.