Minimum lateral bone coverage required for securing fixation of cementless acetabular components in hip dysplasia

Masanori Fujii, Yasuharu Nakashima, Tetsuro Nakamura, Yoshihiro Ito, Toshihiko Hara

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


Objectives. To determine the minimum lateral bone coverage required for securing stable fixation of the porous-coated acetabular components (cups) in hip dysplasia. Methods. In total, 215 primary total hip arthroplasties in 199 patients were reviewed. The average follow-up period was 49months (range: 24-77months).The lateral bone coverage of the cups was assessed by determining the cup center-edge (cup-CE) angle and the bone coverage index (BCI) from anteroposterior pelvic radiographs. Further, cup fixation was determined using the modified DeLee and Charnley classification system. Results. All cups were judged to show stable fixation by bone ingrowth. The cup-CE angle was less than 0° in 7 hips (3.3%) and the minimum cup-CE angle was-9.2° (BCI: 48.8%). Thin radiolucent lines were observed in 5 hips (2.3%), which were not associated with decreased lateral bone coverage. Loosening, osteolysis, dislocation, or revision was not observed in any of the cases during the follow-up period. Conclusion. A cup-CE angle greater than-10° (BCI > 50%) was acceptable for stable bony fixation of the cup. Considering possible errors in manual implantation, we recommend that the cup position be planned such that the cup-CE angle is greater than 0° (BCI > 60%).

Original languageEnglish
Article number4937151
JournalBioMed Research International
Publication statusPublished - 2017

All Science Journal Classification (ASJC) codes

  • General Immunology and Microbiology
  • General Biochemistry,Genetics and Molecular Biology


Dive into the research topics of 'Minimum lateral bone coverage required for securing fixation of cementless acetabular components in hip dysplasia'. Together they form a unique fingerprint.

Cite this