LENGTH OF STAY FOLLOWING PRIMARY TOTAL HIP REPLACEMENT

Abstract

We examined the effect of age, gender, body mass index (BMI), medical comorbidity as represented by the American Society of Anaesthesiologists (ASA) grade, social deprivation, nursing practice, surgical approach, length of incision, type of prosthesis and duration of surgery on length of stay after primary total hip arthroplasty (THA).

Data was collected on 675 consecutive patients in a regional orthopaedic centre in South West England. The length of stay varied from 2 to 196 days and was heavily skewed. Data were therefore analysed by non parametric methods.

To permit comparison of short with protracted length of stay, data were arbitrarily reduced to 2 groups comprising 2 to 14 days for short stays and 15 to 196 for long. These data were analysed by Chi-squared and Fisher’s exact test in univarate and by Logistic regression for multivariate analysis.

The mean length of stay was 11.4 days, an over-estimate compared to the median length of stay of 8 days which more correctly reflects the skewed nature of the distribution. 81.5% of patients left hospital within 2 weeks, 13.6% within 2 and 4 and 4.9% after 4.

On univarate analysis age above 80 years, age between 70 and 79 years, Body Mass Index > 35, ASA grades 3 and 4, transgluteal approaches, long incisions, cemented cups and prolonged operations were associated with longer stays.

On multivariate analysis, age above 80, age between 70 and 80, ASA grades 3 and 4, prolonged operations and long incisions were highly significantly associated with hospital stay of over 2 weeks.

This is the first study to record all the published variables associated with length of stay prospectively and to subject the data to multivariate analysis. Prolonged stay after THA is pre-determined by case mix but slick surgery through limited incisions may reduce the length of admission.