title: The diagnostic performance of radiographic criteria to detect aseptic acetabular component loosening after revision total hip arthroplasty.
abstract: OBJECTIVE
  This study aimed to determine the diagnostic performance of radiographic criteria to detect aseptic acetabular loosening after revision total hip arthroplasty (THA). Secondary aims were to determine the predictive values of different thresholds of migration and to determine the predictive values of radiolucency criteria.
  
  
  METHODS
  Acetabular component migration to re-revision was measured retrospectively using Ein-Bild-Rontgen-Analyse (EBRA-Cup) and manual measurements (Sutherland method) in two groups: Group A, 52 components (48 patients) found not loose at re-revision and Group B, 42 components (36 patients) found loose at re-revision between 1980 and 2015. The presence and extent of radiolucent lines was also assessed.
  
  
  RESULTS
  Using EBRA, both proximal translation and sagittal rotation were excellent diagnostic tests for detecting aseptic loosening. The area under the receiver operating characteristic (ROC) curves was 0.94 and 0.93, respectively. The thresholds of 2.5 mm proximal translation or 2° sagittal rotation (EBRA) in combination with radiolucency criteria had a sensitivity of 93% and specificity of 88% to detect aseptic loosening. The sensitivity, specificity, positive predictive value and negative predictive value (NPV) of radiolucency criteria were 41%, 100%, 100% and 68% respectively. Manual measurements of both proximal translation and sagittal rotation were very good diagnostic tests. The area under the ROC curve was 0.86 and 0.92 respectively. However, manual measurements had a decreased specificity compared with EBRA. Radiolucency criteria had a poor sensitivity and NPV of 41% and 68% respectively.
  
  
  CONCLUSIONS
  This study shows that EBRA and manual migration measurements can be used as accurate diagnostic tools to detect aseptic loosening of cementless acetabular components used at revision THA. Radiolucency criteria should not be used in isolation to exclude loosening of cementless acetabular components used at revision THA given their poor sensitivity and NPV. Cite this article:Bone Joint J2017;99-B:458-64.
authors.affiliation: Royal Adelaide Hospital, Level 4 Bice Building, North Terrace, Adelaide, SA, Australia and PhD Candidate, Discipline of Orthopaedics and Trauma, The University of Adelaide, Adelaide, SA, Australia.
authors.forename: J M
authors.initials: JM
authors.lastname: Abrahams
authors.affiliation: Dongguk University Gyeongju Hospital, Gyeongju, Gyeongsangbuk-do, South Korea.
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Royal Adelaide Hospital, Level 4 Bice Building, Royal Adelaide Hospital, North Terrace, Adelaide, SA, Australia and Discipline of Orthopaedics and Trauma, University of Adelaide, Adelaide, SA, Australia.
authors.forename: S A
authors.initials: SA
authors.lastname: Callary
authors.affiliation: Villa Stuart Sport Clinic, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: De Ieso
authors.affiliation: Royal Adelaide Hospital, Level 4 Bice Building, North Terrace, Adelaide, SA, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Costi
authors.affiliation: The University of Adelaide, Adelaide, SA, Australia and Clinical Director, Department of Orthopaedics and Trauma, Royal Adelaide Hospital, Level 4 Bice Building, North Terrace, Adelaide, SA, Australia.
authors.forename: D W
authors.initials: DW
authors.lastname: Howie
authors.affiliation: The University of Adelaide, Adelaide, SA, Australia and Orthopaedic Consultant, Department of Orthopaedics and Trauma, Royal Adelaide Hospital Level 4 Bice Building, North Terrace, Adelaide, SA, Australia.
authors.forename: L B
authors.initials: LB
authors.lastname: Solomon
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000601:surgery; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging / Q000209:etiology; D006622:Hip Prosthesis; D006801:Humans; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000009:adverse effects / Q000379:methods; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Acetabular migration; Aseptic loosening; Diagnostic performance; Ein-Bild-Rontgen-Analyse; Radiolucency; Revision total hip arthroplasty