Abstract
The Oxford hip score (OHS) at 6 months and five years of less than 27 has previously been reported as having a 5.2% chance of requiring revision of their total hip arthroplasty (THA) within 2 years. We determined whether the OHS obtained at 10 years after surgery would be a suitable screening tool in lieu of clinic visits to detect patients requiring closer monitoring.
We reviewed data from the NZ Joint Registry between January 1999 and December 2016. OHS at 10 years was available for 5,165 non-revised THA patients. Patients were separated into four categories based on their OHS: 3,483 (67%) scored 42–48, 1,023 (20%) scored 34–41, 373 (7%) scored 27–33, and 286 (5%) scored 0–26.
For patients with a 6-month OHS, revision risk within 2 years was 1.3% in the 42–48 group, 2.5% in the 34–41 group, 4.6% in the 27–33 group, and 10.2 % in the 0–27 group. If only patients with a grading of 33 or less were offered clinical follow-up, 659/5165 patients (12.7%) would require evaluation and of these, 46/659 (7%) could be expected to require revision within two years. Of those patients with an OHS > 34 not evaluated, only a small number, 72/4506 (1.6%), might require a revision.
The OHS at 10 years of patients with a THA who have a grading less than 27 is a much stronger predictor of revision than OHS at 6 months or 5 years. Use of the 10 year OHS as a screening tool for THA requires evaluation of only one in eight patients, with the chance of missing 1 in 63 patients not followed up who might require a revision.
