Breed-specific coxofemoral morphometry in three dog breeds: Comparative evaluation of radiography and CT for...

The study was designed to compare femoral and acetabular morphometric parameters obtained via radiography and computed tomography (CT) in German Shepherd Dogs (GSDs), Labrador Retrievers (LABs), and Indian Pariah Dog, with the goals of identifying modality-specific differences, evaluating bilateral symmetry, and informing Orthopaedic implant planning. A total of 72 cadaveric specimens (24 per breed) underwent standardized radiography and CT. Fourteen morphometric parameters, including version angle (VA), femoral neck-shaft angle (FNA), femoral neck diameter (FND), canal flare index (CFI), and acetabular depth (AD), were measured bilaterally. All measurements were performed independently by two trained observers. Inter-observer reliability was assessed between the participating observers. Paired t-tests were used to compare radiographic and CT-derived values, while one-way ANOVA was employed to assess left-right limb symmetry. CT demonstrated greater sensitivity in detecting subtle morphometric variations, particularly in parameters involving cortical transitions and metaphyseal flare. In GSDs, FND (p = 0.004) and CFI (p = 0.028) were significantly higher on CT. LABs showed side-specific differences in right femoral FNA (p = 0.044) and FL (p = 0.020). In Indian Pariah Dogs, CT revealed significant discrepancies in FHO (p = 0.013) and FL (p = 0.020) on the left side, and FND (p = 0.007) and FNL (p = 0.034) on the right. No statistically significant bilateral asymmetry was found in any breed. Inter-observer reliability demonstrated excellent agreement (ICC range: 0.96-1.00; Cohen's Kappa: 0.90-1.00) between observers. Radiography and CT demonstrated general agreement in most morphometric parameters; however, CT offered superior precision in measuring femoral neck dimensions, flare indices, and subtle angular deviations. Bilateral symmetry was preserved across all breeds, supporting the use of contralateral limbs as surgical references. While radiographs remain effective for routine morphometry and screening, CT is preferred for detailed preoperative planning and implant selection particularly in breeds with complex or variable proximal femoral anatomy. A combined imaging strategy enhances diagnostic accuracy and surgical outcomes in veterinary Orthopaedic practice.