Comparison between the Harris- and Oxford Hip Score to evaluate outcomes one-year after total hip arthroplasty.

Harris Hip Score (HHS) is a surgeon administered measurement for assessing hip function before and after total hip arthroplasties (THA). Patient reported outcome measurements (PROMs) such as the Oxford Hip Score (OHS) are increasingly used. HHS was compaired to the OHS assessing whether the HHS can be replaced by the OHS for clinical evaluation of THAs. All 155 patients (167 THAs) were asked to complete an OHS before and one-year after surgery. The surgeon independently scored the HHS at the same time points. We examined and compared the clinimetric properties of both instruments. Internal consistency reliability of the OHS was notably higher than that of the HHS at all occasions. HHS had a higher effect size (4.1) than the OHS (2.1). Ceiling effect at follow up was 55.6% (HHS) and 36.4% (OHS). Spearman's rank correlation between HHS and OHS was 0.57 at baseline and 0.65 and after one year. The correlation between the change scores was 0.50. The Oxford Hip Score is of good use in quality assessment after THA.