Clinical predictors for possible failure after total hip arthroplasty

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 postoperatively. 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.

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.

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.

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.