Oxford hip scores at 6 months and 5 years are associated with total hip revision within the subsequent 2 years.

Abstract

The Oxford hip score (OHS) is commonly reported in research studies as a reflection of pain and function but it is unclear whether it predicts subsequent prosthesis failure. We determined whether OHS obtained at 6 months and 5 years after surgery predicts risk of revision within the subsequent 2 years. We reviewed data from the New Zealand Joint Registry between January 1999 and December 2010. OHS at 6 months was available for 17,831 total hip patients. Patients were separated into four categories based on their OHS: 10,458 (59%) scored 42-48, 4726 (26%) scored 34-41, 1592 (9%) scored 27-33, and 1028 (6%) scored 0-26. Five-year OHSs were available for 3665 patients. Of these patients, 2619 (72%) scored 42-48, 657 (18%) scored 34-41, 225 (6%) scored 27-33, and 164 (4%) scored 0-26. For patients with a 6-month OHS, revision risk within 2 years was 0.4% in the 42-48 group, 1.0% in the 34-41 group, 1.7% in the 27-33 group, and 6.2% in the 0-27 group. For patients with 5-year OHS, revision risk within 2 years was 0.3%, 1.1%, 3.6%, and 6.1%, respectively. Increase in revision risk for the 0-27 versus the 42-48 OHS group was 15-fold at 6 months and 18-fold at 5 years. Our data suggest patients with an OHS of 42-48 at 6 months need a 5-year postoperative appointment. Those patients with a 5-year OHS of 42-48 need not be followed up for a further 5 years.