title: A comparison of the reliability and validity of bone stock loss classification systems used for revision hip surgery.
abstract: Three femoral (Paprosky, American Academy of Orthopaedic Surgeons [AAOS], and Endo-Klinik) and 2 acetabular (Paprosky, AAOS) bone stock loss classification systems were evaluated for reliability. Four observers (2 consultants, 2 registrars) graded the bone loss in 25 patients using preoperative radiographs. Grading was repeated after a minimum of 2 weeks. Interobserver and intraobserver reliability was investigated. The kappa statistic was used to assess levels of agreement. Intraobserver agreement ranged from poor to good. Interobserver agreement ranged from fair to moderate. The validity of the Paprosky classification system was evaluated, comparing preoperative bone stock loss assessment with intraoperative findings. Agreement levels of moderate (femoral classification system) to good (acetabular classification system) were achieved. Bone stock loss classification systems are shown to be inconsistent and unreliable.
authors.affiliation: Department of Orthopaedic Surgery, Bristol Royal Infirmary, Bristol, UK.
authors.forename: Charles
authors.initials: C
authors.lastname: Gozzard
authors.forename: Ashley
authors.initials: A
authors.lastname: Blom
authors.forename: A
authors.initials: A
authors.lastname: Taylor
authors.forename: Evert
authors.initials: E
authors.lastname: Smith
authors.forename: Ian
authors.initials: I
authors.lastname: Learmonth
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D006801:Humans; D010014:Osteolysis / Q000145:classification*; D017063:Outcome Assessment, Health Care; D012086:Reoperation; D015203:Reproducibility of Results