Radiographic grading of femoral stem cementation in hip arthroplasty.
OBJECTIVE
To determine intra and interobserver agreement of the grading system for femoral cementation in hip arthroplasty proposed by Barrack.


METHODS
Immediate anteroposterior and lateral postoperative radiographs of 55 primary total hip arthroplasties were assessed by two observers familiar with the use of this grading system. The assessments were performed on two separate occasions by each observer and independently. The statistical analysis measured the Kappa coefficient, which determines the degree of agreement between tests with categorical variables.


RESULTS
Intraobserver Kappa coefficient varied from 0.43 to 0.68, demonstrating moderate to substantial strength of agreement; interobserver Kappa coefficient varied from 0.19 to 0.44, demonstrating slight to moderate strength of agreement.


CONCLUSIONS
Intra and particularly interobserver agreement are limited in this grading system, even when used by trained individuals. Level of Evidence III, Study of nonconsecutive patients; without consistently applied reference "gold" standard.
Department of Biomechanics, Medicine and Rehabilitation of the Musculoskeletal System of Faculdade de Medicina de Ribeirão Preto (USP) - Ribeirão Preto, SP, Brazil.
Flávio Luís
FL
Garcia
Department of Biomechanics, Medicine and Rehabilitation of the Musculoskeletal System of Faculdade de Medicina de Ribeirão Preto (USP) - Ribeirão Preto, SP, Brazil.
Arthur Tomotaka
AT
Sugo
Department of Biomechanics, Medicine and Rehabilitation of the Musculoskeletal System of Faculdade de Medicina de Ribeirão Preto (USP) - Ribeirão Preto, SP, Brazil.
Celso Hermínio Ferraz
CH
Picado
Arthroplasty, replacement, hip; Cementation; Radiography