There is no definite consensus on the adequate radiographic correction in arthroscopic osteochondroplasty for femoroacetabular impingement: a systematic review and meta-analysis

Purpose The purpose of this study is to evaluate and define what is considered an adequate radiographic correction in arthroscopic osteochondroplasty for FAI and to secondarily assess how radiographic outcomes relate to patient reported outcomes and complications. Methods The databases EMBASE, PubMed, and MEDLINE were searched for relevant literature from database inception until January 2021. Studies were screened by two reviewers independently and in duplicate for studies reporting on post-operative radiographic outcomes in arthroscopic osteochondroplasty for FAI. Data on radiographic outcomes as well as data reporting functional outcomes and complications were recorded. A meta-analysis was used to combine the mean pre- and post-operative radiographic outcomes using a random effects model. A risk of bias assessment was performed for all included studies using the MINORS score. Results The most commonly reported radiographic outcome was the alpha angle with a pooled mean post-operative angle of 44 degrees (95% CI 41 degrees-46 degrees), and mean pre- to post-surgical difference of - 19 degrees (- 22 to - 16, I-2 = 96%), followed by the LCEA with a pooled mean post-operative angle of 30 degrees (95% CI 29-31) and mean difference after surgery of - 4 degrees (- 6 to - 1, I-2 = 97%,). Eleven studies reported on the correlation between radiographic and clinical outcomes with no consistent consensus correlation found amongst the included studies. Similarly, six studies correlated radiographic outcomes with conversion to THA with no consistent consensus correlation found amongst the included studies. Conclusion Based on this review, the main conclusion is that there is no consensus definition on the optimal radiographic correction for FAI and there was no consistent correlation between radiographic correction and functional outcomes. However, based on the uniform improvement in functional outcomes, this review suggests a post-operative alpha angle target of 44 degrees with a correction target of 19 degrees and LCEA target of 30 degrees with a correction target of 3 degrees.