Evaluation of the accuracy and intra- and interobserver reliability of three manual laxity tests for canine cranial cruciate ligament rupture-An ex vivo kinetic and kinematic study

ObjectivesTo investigate the accuracy and intra- and interobserver reliability of the cranial drawer test (CD), tibial compression test (TCT), and the new tibial pivot compression test (TPCT) in an experimental setting resembling acute cranial cruciate ligament rupture (CCLR) and to elucidate the ability to subjectively estimate cranial tibial translation (CTT) during testing. Study designExperimental ex vivo study. Sample populationTen cadaveric hindlimbs of large dogs. MethodsKinetic and 3D-kinematic data was collected while three observers performed the tests on each specimen with intact (INTACT) and transected cranial cruciate ligament (CCLD) and compared using three-way repeated-measures ANOVA. Subjectively estimated CTT (SCTT), obtained during a separate round of testing, was compared to kinematic data by Pearson correlation. ResultsCTT was significantly higher for CCLD than for INTACT for all tests, resulting in 100% sensitivity and specificity. TPCT induced the highest CTT and internal rotation. Intra- and interobserver agreement of translation was excellent. For rotation and kinetics, agreement was more variable. SCTT strongly correlated with the objectively measured values. ConclusionThe CD, TCT and the new TPCT were all accurate and reliable. The high translations and rotations during TPCT are promising, encouraging further development of this test. SCTT was reliable in our experimental setting. Clinical significanceVeterinary manual laxity tests are accurate and reliable in acute CCLR. The TPCT might have potential for the assessment of subtle and rotational canine stifle instabilities. The high reliability of SCTT implies that grading schemes for stifle laxity, similar to human medicine, could be developed.