Hip dysplasia is not uncommon but frequently overlooked: a crosssectional study based on radiographic examination of 1,870 adults

Rebecka Leide; Anna Bohman; Daniel Wenger; Søren Overgaard; Carl Johan Tiderius; Cecilia Rogmark

doi:10.1080/17453674.2021.1936918

Authors

Rebecka Leide Department of Clinical Sciences, Lund University, Lund, Sweden; Department of Orthopedics, Halland Hospital, Halmstad, Sweden
Anna Bohman Department of Emergency Medicine, Central Hospital, Kristianstad, Sweden
Daniel Wenger Department of Clinical Sciences, Lund University, Lund, Sweden; Department of Orthopedics, Skåne University Hospital, Lund and Malmö, Sweden
Søren Overgaard Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; Department of Orthopaedic Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg, Denmark
Carl Johan Tiderius Department of Clinical Sciences, Lund University, Lund, Sweden; 2 Department of Orthopedics, Halland Hospital, Halmstad, Sweden; Department of Orthopedics, Skåne University Hospital, Lund and Malmö, Sweden
Cecilia Rogmark Department of Clinical Sciences, Lund University, Lund, Sweden; Department of Orthopedics, Skåne University Hospital, Lund and Malmö, Sweden

DOI:

https://doi.org/10.1080/17453674.2021.1936918

Abstract

Background and purpose — Hip dysplasia in adults is a deformity in which the acetabulum inadequately covers the femoral head. The prevalence is sparingly described in the literature. We investigated the prevalence in Malmö (Sweden) and assessed whether the condition was recognized in the radiology reports.

Subjects and methods — All pelvic radiographs performed in Malmö during 2007–2008 on subjects aged 20–70 years with a Swedish personal identity number were assessed. 1,870 digital radiographs were eligible for analysis. The lateral center-edge angle (LCEA) and acetabular index angle (AIA) were measured. Hip dysplasia was defined as an LCEA ≤ 20°. Intraclass correlation coefficients (ICC) for intra-observer measurements ranged from 0.87 (AIA, 95% CI 0.78–0.93) to 0.98 (LCEA, CI 0.97–0.99).

Results — The prevalence of hip dysplasia (LCEA ≤ 20°) was 5.2% (CI 4.3–6.3), (98/1,870). There was no statistically significant difference between the sexes for either prevalence of hip dysplasia or mean LCEA. The mean AIA was 0.9° (CI 0.3–1.3) higher in men (4.1 SD 5.5) compared with women (3.2 SD 5.4). The radiologists had reported hip dysplasia in 7 of the 98 cases.

Interpretation — The prevalence of hip dysplasia in Malmö (Sweden) is similar to previously reported data from Copenhagen (Denmark) and Bergen (Norway). Our results indicate that hip dysplasia is often overlooked by radiologists, which may influence patient treatment.