title: Assessment of the hip reduction angle for predicting osteoarthritis of the hip in the Labrador Retriever.
abstract: Hip palpation has been used to provide semiquantitative information regarding passive joint laxity and susceptibility to hip dysplasia. The purpose of this study was to: (1) evaluate the intra- and inter-examiner repeatability of the hip reduction angle measured at 4 months of age by three examiners using manual goniometry and an electromagnetic tracking system; (2) compare the hip reduction angle measured with manual goniometry to the hip reduction angle measured with the electromagnetic tracking system; and (3) evaluate the hip reduction angle, distraction index and Ortolani manoeuvre at 4 months of age as predictors of the development of hip osteoarthritis at 12 months of age in 11 Labrador Retriever dogs. Intra- and inter-examiner repeatability was demonstrated for both the manual and electromagnetic goniometric measurement of the hip reduction angle (coefficient of variation < 4.3% and < 6.1%; and P = 0.163 and P = 0.836 respectively). The hip reduction angle measured by manual goniometry was moderately correlated to the hip reduction angle measured by the electromagnetic tracking system (r = 0.603, P < 0.0000). The hip reduction angle measured by manual and electromagnetic goniometry was a poor predictor of osteoarthritis at 12 months of age (r = 0.231, P < 0.062, and r = 0.321, P < 0.01). The distraction index was moderately correlated with the development of osteoarthritis by 12 months of age (r = 0.493, P < 0.0000). The Ortolani sign was sensitive (100%) but not specific (41%) for the development of osteoarthritis at 12 months of age. The hip reduction angle did not further quantify the Ortolani manoeuvre as a predictor of osteoarthritis in Labrador Retrievers.
authors.affiliation: School of Veterinary and Biomedical Sciences, Division of Health Sciences, Murdoch University, WA 6150. gordon@rivergumvet.com.au
authors.forename: G S
authors.initials: GS
authors.lastname: Corfield
authors.forename: R A
authors.initials: RA
authors.lastname: Read
authors.forename: K A
authors.initials: KA
authors.lastname: Eastley
authors.forename: J L
authors.initials: JL
authors.lastname: Richardson
authors.forename: I D
authors.initials: ID
authors.lastname: Robertson
authors.forename: R
authors.initials: R
authors.lastname: Day
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001699:Biometry / Q000379:methods*; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology*; D004285:Dogs; D005260:Female; D006619:Hip Dysplasia, Canine / Q000150:complications / Q000175:diagnosis / Q000473:pathology*; D007593:Joint Instability / Q000150:complications / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D008297:Male; D015588:Observer Variation; D015207:Osteoarthritis, Hip / Q000453:epidemiology / Q000209:etiology / Q000662:veterinary*; D010173:Palpation / Q000662:veterinary; D010808:Physical Examination / Q000662:veterinary; D011237:Predictive Value of Tests; D012720:Severity of Illness Index