Correlations between the Harris Hip Score and the Visual Analogue Scale in the assessment of total hip replacement in hip dysplasia

Total hip replacement is one of the most frequently performed orthopaedic interventions that can significantly improve the functional status and the quality of life of patients suffering from hip arthrosis. Recently patient satisfaction and patient-reported results of total hip arthroplasty are increasingly emphasised as important tools for the assessments of these interventions. For patients with arthrosis secondary to hip dysplasia, these evaluations can be more difficult, due to younger age and higher functional demands. In this study we compared the Visual Analogue Scale and the Harris Hip Score in order to determine the correlations between these instruments and analyse the possibility of replacing the Harris Score with the Visual Analogue Scale in evaluating the results of hip surgery in patients with dysplastic hips. Our study included 37 women and 4 men (53 hips), with a mean age of 50.96 years (35-58 years), followed for a mean of 4 years postoperatively. Both assessment instruments were used preoperatively and at the follow-up visits. We observed a positive correlation of the values of the Visual Analogue Scale and the Harris Hip Score both preoperatively and postoperatively, with correlation coefficients of +0.71(P <0.001) and +0.77 (P <0.001) respectively. Given these positive correlations, we assumed that the Visual Analogue Scale could replace the Harris Hip Score in the evaluation of patients after total hip replacement. Still it is recommended to combine the Visual Analogue Scale with objective measurements and radiological examination in order to identify significant postoperative changes.