Assessment of the Diagnostic Value of the Sit Test as a Screening Test for Cranial Cruciate Ligament Rupture in Dogs

Diagnosis of cranial cruciate ligament rupture (CCLR) is primarily through physical examination, imaging, and intra-articular assessment. Assessment of sit position where affected dogs abduct and extend the stifle to reduce discomfort has been proposed to aid diagnosis but not evaluated as a diagnostic test. This study aimed to evaluate the relationship between sit position and CCLR and assess the sit test as a diagnostic tool.Dogs with CCLR or hip dysplasia (HD) diagnosis were prospectively recruited and allocated to affected (CCLR) and unaffected (HD and normal stifles) groups. Dogs were recorded sitting and videos reviewed by three European College of Veterinary Surgeons (ECVS) diplomates and three ECVS residents. Sit position was graded normal, abnormal, equivocal, or inconclusive. Interobserver agreement, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were evaluated.Eighty-three dogs (56 affected, 70 unaffected limbs) met inclusion criteria. The sit test demonstrated 61.5% sensitivity, 81.0% specificity, 71.6% PPV, 73.0% NPV, and 72.5% accuracy for CCLR diagnosis. Moderate interobserver agreement was found (κ = 0.536, p < 0.001). Of dogs with the CCLR, 72.5% were correctly identified; however, 27.0% of dogs with a negative sit test were affected by CCLR.The sit test offers a screening test for CCLR in conscious dogs with greater sensitivity and similar specificity to cranial draw and tibial compression tests. It may be a valuable addition in CCLR diagnosis, particularly for conscious remote evaluation.