The Journal of Hip Surgery 2017; 01(04): 167-172
DOI: 10.1055/s-0038-1635102
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Successful Outcomes at Midterm Follow-up of Periacetabular Osteotomy Done for Mild Hip Dysplasia

Rafael J. Sierra
1   Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
G. David Potter
1   Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
Eduardo N. Novais
2   Child and Young Adult Hip Preservation, Boston Children's Hospital, Boston, Massachusetts
3   Assistant Professor, Harvard Medical School, Boston, Massachusetts
Robert T. Trousdale
1   Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota
› Author Affiliations
Further Information

Publication History

30 August 2017

21 December 2017

Publication Date:
19 March 2018 (online)


Young hip surgeons are often faced with the decision to either perform arthroscopic surgery or a periacetabular osteotomy (PAO) in patients with symptomatic mild hip dysplasia (MHD). There is, however, a paucity of data on the results of PAO in this group. The aim of this paper is to report the results of PAOs in patients with MHD and compare those to hips with more severe forms of hip dysplasia (SHD). This data can then be used to compare emerging data reporting the results of hip arthroscopy for MHD. From January, 1996 to May, 2009, 299 hips in 268 patients were identified that underwent PAO at one institution. After removing those with <2 years of follow-up, 182 hips were followed up. The average age of the cohort was 31 years, and 85% were female. Nineteen hips with lateral center edge (LCE) angle from 18 to 25° and a Tönnis angle (TA) between 10 and 15° were considered to have MHD. This group was compared with the rest of the cohort (SHD). The mean clinical follow-up for the MHD group was 121 months. There was no significant difference in demographic variables between the groups. There were no complications in the MHD cohort. Surgical correction resulted in significant improvements in all radiographic measurements consistent with hip dysplasia in both groups. The Harris Hip Score (HHS) improved significantly in both groups ([MHD: 52–92] [SHD: 66–89]). Two hips (10.5%) in the MHD group and 15 hips (9.2%) in the SHD group underwent future THA (p = 0.69). The survivorship free from THA was 100%, 100%, and 86% at 3, 5, and 10 years, respectively, in the MHD group. The corresponding rates for hips in the control group at 3, 5, and 10 years, respectively, were 99%, 95%, and 81%. PAO in patients with MHD provides predictable improvements in pain, function, and results that are durable and comparable to hips with SHD. This data should be used to compare the early and midterm results of arthroscopic surgery performed in mildly dysplastic hips.