THA Risk Score Validated for Predicting Arthroplasty Surgery

A total hip arthroplasty score described by Redmund et al., can accurately predict which hip arthroscopy patients are at greatest risk to convert to total hip arthroplasty.

“The most common surgery after arthroscopy is total hip arthroplasty (THA), which unfortunately occurs within 2 years of arthroscopy in up to 10% of patients,” the researchers wrote.

In their study, “Risk of Conversion to Arthroplasty After Hip Arthroscopy: Validation of a Published Risk Score Using an Independent Prospectively Collected Database,” published in the journal The American Journal of Sports Medicine, they used an independent database to externally validate a previously published risk factor score. The purpose was to determine its accuracy in predicting conversion of hip arthroscopy to THA at a minimum of two years post-surgery.

All of the 187 patients underwent hip arthroscopy at one center between November 2015 and March 2017. For these patients, the researchers analyzed components of the THA risk score including age, modified Harris Hip Score, lateral center-edge angle, revision procedure, femoral version, and femoral and acetabular Outerbridge scores.

The majority of the patients were women with a mean age of 36.0±12.4 years. In total, 13 patients converted to THA at a mean of 1.6±09 years. Those patients who converted to THA had a mean predicted arthroplasty risk of 22.6% compared with patients who didn’t need subsequent conversion who had a predicted risk of 4.6%±5.3% (p < .01).

“The Brier score for the calculator was 0.04 (p =.53), which was not statistically different from ideal calibration, and the calculator demonstrated a satisfactory area under the curve of 0.894 (p < .001),” the authors wrote.

“This external validation study supported our hypothesis in that the THA risk score described by Redmond et al was found to accurately predict which patients undergoing hip arthroscopy were at risk for converting to subsequent arthroplasty, with satisfactory discriminatory, receiver operating characteristic (ROC) curve, and Brier score calibration characteristics. These findings are important in that they provide surgeons with validated tools identify the patients at greater risk for failure after hip arthroscopy and assist in perioperative counseling and decision making.”