Primary and revision hip arthroplasty: 5-year outcomes and influence of age and comorbidity.

OBJECTIVE: Revision hip arthroplasty is associated with less favorable short and longterm results than primary total hip arthroplasty (THA). We compared quality of life and satisfaction 5 years after the 2 interventions, to determine the influence of patient characteristics on poorer outcomes after revision, and to analyze if their influence differed for primary and for revision arthroplasty. METHODS: This was a hospital-based prospective cohort study including patients who underwent primary (n = 435) or revision THA (n = 116). Quality of life was measured by Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Medical Outcomes Study Short Form-12 questionnaire. Satisfaction was evaluated with a visual analog scale. RESULTS: Patients undergoing a revision were older, more often obese, and had more medical and orthopedic comorbidities. Five years after surgery, 349 patients with primary THA and 85 with revisions were available for followup. Unadjusted quality of life and satisfaction were significantly lower after revision (Harris Hip Score 76.7 vs 88.1; WOMAC pain 66.4 vs 73.3; WOMAC function 61.6 vs 70.0; satisfaction 7.7 vs 8.9). Adjustment for patient characteristics revealed that this difference was partly explained by the greater morbidity and older age of patients undergoing revision. The influence of age, comorbidities, and preoperative function on 5-year outcomes did not substantially differ for the 2 intervention groups. However, obesity was associated with a stronger negative effect on revision surgery. CONCLUSION: Patients and physicians should acknowledge additional risks and consequently lower results associated with revision THA. Better information and medical preparation before surgery may help to improve the success of revision surgery.