Inter-rater reliability in performing stifle goniometry in normal and cranial cruciate ligament disease affected dogs: a prospective randomized controlled study.

Abstract

BACKGROUND: Goniometry can be performed clinically in dogs with cranial cruciate ligament disease (CCLD). The purpose of this study was&#xa0;(1) to compare reliability of stifle goniometry in dogs with CCLD and healthy dogs and&#xa0;(2) to investigate the effect of compliance on measurements. Dogs presented for surgical intervention for CCLD (CCL-Dogs; n&#x2009;=&#x2009;15) and orthopedically healthy dogs (C-Dogs; n&#x2009;=&#x2009;11) were enrolled in this prospective randomized controlled trial. In each dog, three observers randomly measured maximum stifle flexion (mSF) and maximum stifle extension (mSE) three times with a standard goniometer with the scale covered, while dog compliance was scored (Scores: C0: excellent - C4: poor). Intraclass correlation coefficient (ICC) was calculated for intra-/interobserver reliability. Effects on measurements were evaluated with mixed-effect models (MEM). RESULTS: Maximum stifle extension and mSE-compliance were significantly decreased in CCL-Dogs compared to C-Dogs (p&#x2009;&#x2264;&#x2009;0.004), but mSF and mSF-compliance did not differ between groups. Intraobserver reliability was excellent for all dogs during mSE (ICC:0.75-0.99) and mSF (ICC:0.89-0.99). Interobserver reliability was excellent for mSF in both groups (ICC: C-Dogs:0.84, CCL-Dogs:0.9) and for mSE in CCL-Dogs (ICC:0.94) but only fair for mSE in C-Dogs (ICC:0.58). Robust MEM showed that the combined average of all mSE measurements of all three observers was affected by compliance in both groups (p&#x2009;<&#x2009;0.001). This effect was not observed for single mSE-measurements by themselves. CONCLUSION: The results of this study indicate that compliance may affect goniometric stifle extension measurements in healthy and CCLD dogs. In a clinical setting, intra-/interobserver reliability was excellent for all measurements except for maximum stifle extension in healthy dogs.