Natural History of Nonoperatively Treated Borderline Acetabular Dysplasia in Young Adults and Factors Associated With Inferior Functional Outcome

At a mean 15-year follow-up, 19 of 90 (21%) of borderline hips required preservation surgery. Of the 45 nonsurgical hips, 4 (9%) exhibited mild OA progression, and 3 of 4 hips (75%) maintained excellent functional outcomes. Acetabular retroversion and labrum hypertrophy were associated with poorer function but did not predict OA progression. Persistent symptoms were common in patients with labrum hypertrophy after HAS for FAI.