High Degree of Variability in Reporting of Clinical and Patient-Reported Outcomes After Hip Arthroscopy

Hip arthroscopy for the treatment of intra-articular pathology is a rapidly expanding field. Outcome measures should be reported to document the efficacy of arthroscopic procedures; however, the most effective outcome measures are not established.

To evaluate the variability in outcomes reported after hip arthroscopy and to compare the responsiveness of patient-reported outcome (PRO) instruments.

Systematic review.

We reviewed primary hip arthroscopy literature between January 2011 and September 2016 using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Patient and study characteristics were recorded. Pre- and postoperative means and SDs of PROs were recorded from articles that used 2 or more PROs with a 1-year minimum follow-up. From this subset of articles, we compared the responsiveness between PRO instruments using the effect size, standard response mean, and relative efficiency.

We identified 130 studies that met our inclusion/exclusion criteria, which totaled 16,970 patients (17,511 hips, mean age = 37.0 years, mean body mass index = 25.9 kg/m²). Radiographic measures were reported in 100 studies. The alpha angle and center-edge angle were the most common measures. Range of motion was reported in 81 of 130 articles. PROs were reported in 129 of 130 articles, and 21 different PRO instruments were identified. The mean number of PROs per article was 3.2, and 78% used 2 or more PROs. The most commonly used PRO was the modified Harris Hip Score, followed by the Hip Outcome Score (HOS)-Activities of Daily Living, HOS-Sport, visual analog scale, and Nonarthritic Hip Score (NAHS). The 2 most responsive PRO tools were the International Hip Outcome Tool (iHOT)-12 and the NAHS.

Outcomes reporting is highly variable in the hip arthroscopy literature. More than 20 different PRO instruments have been used, which makes comparison across studies difficult. A uniform set of outcome measures would allow for clearer interpretation of the hip arthroscopy literature and offer potential conclusions from pooled data. On the basis of our comparative responsiveness results and previously reported psychometric properties of the different PRO instruments, we recommend more widespread adoption of the iHOT PROs instruments to assess hip arthroscopy outcomes.