There has been a shift toward using patient-reported outcome measures (PROMs) to capture functional improvement and patient satisfaction after total hip arthroplasty (THA). Because there is no standard measure or set of measures, variability in reporting patterns makes comparison across studies difficult.
We performed a review of the literature using the keywords “total hip arthroplasty” and “total hip replacement” to electronically search PubMed, using the date range August 1, 2014, to August 1, 2019. Randomized clinical trials (RCTs) that were published in 12 high-impact journals were analyzed.
One hundred and fifty-nine RCTs were included. The most common topic of investigation was hip implant design and materials, followed by the effect of different hip approaches on patient outcomes. The follow-up period was classified as short-term (<2 years), mid-term (2 to 10 years), or long-term (>10 years). Only 6% of the RCTs reported long-term outcomes. The comprehensiveness of studies was determined on the basis of how many of the 7 following outcome domains were assessed: subjective hip function (PROMs), objective outcome measures (examination findings, laboratory values, etc.), imaging analysis, survivorship, patient satisfaction, pain assessment, and postoperative complications. Subjective hip function and imaging findings were the most commonly reported outcome domains, while implant survivorship and patient satisfaction were the least frequently reported. There was substantial variation in outcome reporting, with 35 unique PROMs utilized to assess subjective hip function. Although the Harris hip score was the most commonly used joint-specific PROM, it was only reported in 42% of the studies. None of the RCTs reported results in all 7 outcome domains, and 13.8% of studies reported results in only 1 outcome domain.
There is substantial variability and a lack of comprehensiveness in outcome measures used to report results in THA clinical trials, making it nearly impossible to perform cross-study comparisons.
There is an immediate need for the establishment of a standardized set of measures to allow comparison of outcomes across studies.