Abstract

PURPOSE: To assess the utility of the femoro-epiphyseal acetabular roof (FEAR) index as a diagnostic tool in hip preservation surgery.METHODS: MEDLINE, EMBASE, and PubMed were searched from database inception until May 2022, for literature addressing the utility of the FEAR index in patients undergoing hip preservation surgery and the results are presented descriptively.RESULTS: Overall, there were a total of 11 studies comprising 1,458 patients included in this review. The intra-observer agreement for the FEAR index was reported by 3/11 studies (ICC range = 0.86 to 0.99) while the inter-observer agreement was reported by 8/11 studies (ICC range = 0.776-1). Among the 5 studies that differentiated between hip instability and hip impingement, the mean FEAR index in 319 patients in the instability group ranged from 3.01 to 13.3 degrees while the mean FEAR index in 239 patients in the impingement group ranged from -10 to -0.77 degrees and the mean FEAR index in 105 patients in the control group ranged from -13 to -7.7 degrees. Three studies defined a specific cut-off value for the FEAR index with 1 study defining a cutoff value of 5 degrees which correctly predicted treatment decision between PAO vs osteochondroplasty 79% of the time with an AUC of 0.89, while another defined a cutoff of 2 degrees which correctly predicted treatment 90% of the time and the last study set a threshold of 3 degrees which provided an AUC of 0.86 for correctly predicting treatment decision.CONCLUSION: This review demonstrates that the FEAR index has a high agreement and consistent application, making it a useful diagnostic tool in hip preservation surgery particularly in patients with borderline dysplastic hips. However, given the variability in FEAR index cut off values across studies, there is no absolute consensus value that dictates treatment decision.LEVEL OF EVIDENCE: Level IV; Systematic Review of Level II-IV studies.

View details for DOI 10.1016/j.arthro.2022.11.041

View details for PubMedID 36638902