Clinical predictors for possible failure after total hip arthroplasty

Introduction: With the rising number of total hip arthroplasties (THAs) each year, it is increasingly important for surgeons to have evidence-based information on which to determine how often patients should be examined post-operatively. The purpose of this research was to determine whether it is possible to identify - based on Harris Hip Score (HHS) - early signs or predictors of THA failure so that methods of postoperative follow-up can be scheduled in advance of the time frame indicated by those predictors of failure. Methods: The HHS of 9,949 primary THAs performed from 1973 to 2012 was reviewed retrospectively to identify the clinical predictors of failure. 1,131 hips were completely lost to follow-up, leaving 8,331 primary THAs in 6,979 patients. Time to failure was recorded with Kaplan-Meier analysis performed with aseptic loosening or revision of any component as the endpoint. Results: Regression analysis revealed that a pain score of 30 or less at any time of follow-up (p<0.0001) was a significant risk and strongly indicative of later failing. A low distance walked score of 5 or less at 6 months (p = 0.0087) and 1 year (p = 0.0167) served as an early predictor of future failure. A lower stairs score of 2 or less was also an early predictor at 1 year (p = 0.0343) and at 3 years (p = 0.0245). A lower limp score of 8 or less was a mid-term predictor at 3 (p = 0.0001), 5 (p = 0.0002), 7 (p = 0.0191) and 10 (0.0028) years postoperative follow-up. Conclusions: Pain, walk, stairs and limp scores are predictive of THA failure. Surgeons with patients who present with these indicators should optimise postoperative follow-ups to alert their patients.