Hip survival after periacetabular osteotomy in patients with acetabular dysplasia, acetabular retroversion, congenital dislocation of the hip, or Legg-Calvé-Perthes disease: a cohort study on 1,501 hips

Abstract

Background and purpose: Previous studies on hip survival following periacetabular osteotomy (PAO) have reported isolated data for the treatment of 1 underlying condition, making comparison between patient groups difficult. We report the hip survival after PAO in patients with acetabular dysplasia (AD), acetabular retroversion (AR), congenital dislocation of the hip (CDH), and Legg-Calvé-Perthes disease (LCPD) with total hip arthroplasty (THA) as primary endpoint and secondarily the risk of subsequent hip-related operations other than THA.

Patients and methods: From 1997 to December 2021, 1,501 hips (1,203 patients) underwent PAO in a single center (Odense University Hospital). We identified conversions to THA and other subsequent hip-related operations through patient files and the Danish National Patient Registry (DNPR).

Results: 123 (8.2%) of the total cohort of 1,501 hips were converted to THA within the study period. The overall Kaplan-Meier hip survival rate was 71% (95% confidence interval [CI] 61-79) at 24 years with a mean follow-up of 7.6 years (range 0.02-25). The individual Kaplan-Meier hip survival rates at 15 years were 81% (CI 76-86) for AD, 94% (CI 91-96) for AR, 84% (CI 66-93) for CDH, and 66% (CI 49-79) for LCPD. In total, the overall risk of additional hip-related operations was 48% (of which 92% were screw removal).

Conclusion: Encouragingly, 71% of hips were preserved 24 years after PAO. We found that AR patients had the highest (94%) PAO survivorship at 15 years compared with the other underlying hip conditions. Almost half of PAO patients may undergo later additional surgery, of which screw removal is the primary intervention. Overall long-term survival, risk factors for conversion to THA, and risk of additional surgery are relevant information for shared decision-making.

Figure 1

Study cohort. Flowchart showing inclusions and follow-up from patient files with full follow-up from 1997 to 2021 and follow-up from the Danish National Patient Registry (DNPR) from 1997 to 2018. A total of 1,501 hips were included in this study.

Figure 2

Kaplan–Meier survivorship curve (with 95% CI) after periacetabular osteotomy in 1,501 hips (1,479 hips at risk after censoring) with total hip arthroplasty (THA) as endpoint. Each conversion to THA is seen as a decrease on the curve. The hip survival rate is 71% (CI 61–79) at 24 years.

Figure 3

Kaplan–Meier survivorship curve for the 4 individual indications with total hip arthroplasty as endpoint. Each conversion to total hip arthroplasty is seen as a decrease on the curve. AD, acetabular dysplasia; AR, acetabular retroversion; CDH, congenital dislocation of the hip; LCPD, Legg-Calvé-Perthes disease.