Relationships between results of the Ortolani method of hip joint palpation and distraction index, Norberg angle, and hip score in dogs

Objective - To determine whether results of the Ortolani method of hip joint palpation in dogs were related to distraction index (DI), Norberg angle, or radiographic hip score. Design - Cross-sectional study. Animals - 459 clinically normal dogs. Procedure - Dogs were sedated for radiography and palpation of the hip joints. Results of hip joint palpation were classified as negative, mild positive, moderate positive, or severe positive. Distraction indices were measured for all dogs. Norberg angles were measured for 380 dogs for which ventrodorsal hip-extended radiographic projections were available. Hip scores assigned by the Orthopedic Foundation for Animals (OFA) were available for 95 dogs. Results - Age, weight, and sex were not significantly associated with results of hip joint palpation. There was moderate correlation between results of hip joint palpation and DI (r = 0.636), low-moderate correlation between results of hip joint palpation and OFA hip scores (r_s = 0.437), and weak negative correlation (r = -0.236) between results of hip joint palpation and Norberg angle. For joints without degenerative joint disease (DJD), there was a significant linear relationship between results of hip palpation and DI; however, for joints with DJD, there was not. Results of hip joint palpation were 5.3-fold as likely to be negative for dogs with DJD as for dogs without. Clinical Implications - Results of hip joint palpation were at best moderately correlated with radiographic measures of hip joint laxity. Therefore, hip joint palpation should be combined with hip-extended and stress radiography when assessing hip joint quality.