.02&p<0.001, respectively) Analgesic requirements were not significantly different between hip and knee replacements. Early mobilization occurred in 95% of patients. Length of stay was reduced significantly in hip (1.8 days, p=0.003) and knee (1.9 days(p<0.001) replacements following ERP. Cost analysis demonstrated a potential annual saving of approximately £200,000 for the study unit if ERP was applied to all elective hip and knee arthroplasty procedures.