Comparison of radiographic and computed tomographic acetabular index in small-breed dogs: a preliminary study using Maltese and Shih Tzu

Abstract

Background The morphometry of the acetabulum is one source of information that assists in the clinical diagnosis of the hip and influences the proper selection of a prosthesis, reducing post-operative complications such as those seen in total hip replacement (THR). However, acetabular parameters in small-breed dogs are rarely reported. Objectives To investigate acetabular parameters using radiography and computed tomography (CT) in small-breed dogs with Maltese and Shih Tzu dogs used as model breeds. Methods Standard calibrated, extended hip radiographs and CT images were obtained. Subsequently, acetabular width (AW) in various directions was measured using radiography and CT, whereas acetabular depth (AD) was obtained by CT. Acetabular index (AI) is a ratio calculated from AD and AW. Results The values of AW and AD were much higher in Shih Tzu than in Maltese dogs. Male Shih Tzus showed higher values of these parameters than females, while sex-based differences in most of the parameters could not be detected in Maltese. Body weight, but not age, influenced AWs and ADs. While AWs and ADs were influenced by several factors, AI was comparable among the assessed factors and between Maltese and Shih Tzu dogs ( p = 0.172; 31.42 ± 1.35 and 32.60 ± 1.80, respectively). Also, AI did not vary with breed, sex, or body size. Conclusions The obtained radiographic and CT acetabular parameters could be useful as guidelines for evaluating the acetabulum of small-breed dogs in clinical practice.

Three-Dimensional Morphometry of the Canine Pelvis: Implications for Total Hip Replacement Surgery

“…30 A similar comparison between two smallbreed dogs, the Shih Tzu and the Maltese, showed that the Shih Tzu acetabulum was deeper and wider than that of the Maltese. 31 Such variety in acetabular morphometry between breeds may have an impact on acetabular measurements and surgical planning for THR, so further investigations are needed to verify it.…”

“…In small-breed dogs, sex was identified as a variable that impacted acetabular width and depth, but acetabular index measurements were similar in the two sexes, suggesting that their acetabula are shaped similarly. 31 Currently, it is unclear whether sex-related variation in canine acetabular morphometry is sufficient to impact recommendations for optimum component positioning in THR.…”