Vet Comp Orthop Traumatol 2020; 33(04): 274-278
DOI: 10.1055/s-0040-1709460
Original Research
Georg Thieme Verlag KG Stuttgart · New York

Comparison of Reliability of Norberg Angle and Distraction Index as Measurements for Hip Laxity in Dogs

1  Clinic of Small Animal Surgery and Reproduction, Centre of Veterinary Clinical Medicine, LMU Munich, Munich, Germany
,
Andreas Brühschwein
1  Clinic of Small Animal Surgery and Reproduction, Centre of Veterinary Clinical Medicine, LMU Munich, Munich, Germany
,
Silvia Wagner
1  Clinic of Small Animal Surgery and Reproduction, Centre of Veterinary Clinical Medicine, LMU Munich, Munich, Germany
,
Sven Reese
2  Institute of Veterinary Anatomy, Histology and Embryology, LMU Munich, Munich, Germany
,
Andrea Meyer-Lindenberg
1  Clinic of Small Animal Surgery and Reproduction, Centre of Veterinary Clinical Medicine, LMU Munich, Munich, Germany
› Author Affiliations
Further Information

Publication History

09 July 2019

16 February 2020

Publication Date:
29 April 2020 (online)

Abstract

Objective The main purpose of the study was to compare reliability of measurements for the evaluation of hip joint laxity in 59 dogs.

Materials and Methods Measurement of the distraction index (DI) of the PennHIP method and the Norberg angle (NA) of the Fédération Cynologique Internationale (FCI) scoring scheme as well as scoring according to the FCI scheme and the Swiss scoring scheme were performed by three observers at different level of experience. For each dog, two radiographs were acquired with each method by the same operator to evaluate intraoperator-reliability.

Results Intraoperator-reliability was slightly better for the NA compared with the DI with an intraclass correlation coefficient (ICC) of 0.962 and 0.892 respectively. The ICC showed excellent results in intraobserver-reliability and interobserver-reliability for both the NA (ICC 0.975; 0.969) and the DI (ICC 0.986; 0.972). Thus, the NA as well as the DI can be considered as reliable measurements. The FCI scheme and the Swiss scoring scheme provide similar reliability. While the FCI scheme seems to be slightly more reliable in experienced observers (Kappa FCI 0.687; Kappa Swiss 0.681), the Swiss scoring scheme had a noticeable better reliability for the unexperienced observer (Kappa FCI 0.465; Kappa Swiss 0.514).

Clinical Significance The Swiss scoring scheme provides a structured guideline for the interpretation of hip radiographs and can thus be recommended to unexperienced observers.

Authors' Contributions

Julius Klever and Andreas Brühschwein contributed to conception of study, study design, acquisition of data and data analysis and interpretation. Silvia Wagner contributed to acquisition of data. Sven Reese contributed to data analysis and interpretation. Andrea Meyer-Lindenberg contributed to conception of study and study design. All authors drafted, revised and approved the submitted manuscript.