A Clavé1, L Kerboull2, T Musset3, X Flecher4, D Huten5, C Lefèvre1, F Gaucher6, E Stindel7. 1. Service de chirurgie orthopédique et traumatologique, faculté de médecine, université de Bretagne-Occidentale, hôpital de la Cavale-Blanche, CHRU de Brest, boulevard Tanguy-Prigent, 29200 Brest, France. 2. Centre médico-chirurgical Paris V, 36, boulevard Saint-Marcel, 75005 Paris, France. 3. Clinique mutualiste de la Porte-de-L'Orient, 3, rue Robert-de-La-Croix, 56324 L'Orient, France. 4. Institut du mouvement et de l'appareil locomoteur, faculté de médecine, université d'Aix-Marseille, hôpital Sainte Marguerite, Marseille, France. 5. Service de chirurgie orthopédique, réparatrice et traumatologique, faculté de médecine Rennes, université de Rennes, hôpital Sud, CHRU de Rennes, 16, boulevard de Bulgarie, 35203 Rennes, France. 6. Service de chirurgie orthopédique, Hôtel-Dieu-de-Pont-l'Abbé, rue Signor, 29120 Pont-l'Abbé, France. 7. Service de chirurgie orthopédique et traumatologique, faculté de médecine, université de Bretagne-Occidentale, hôpital de la Cavale-Blanche, CHRU de Brest, boulevard Tanguy-Prigent, 29200 Brest, France. Electronic address: eric.stindel@univ-brest.fr.
Abstract
INTRODUCTION: Developmental dysplasia of the hip (DDH) leads to multiple treatment challenges during adulthood. Surgical treatment is mainly based on radiographic evaluation of the anatomical alterations. Several classification systems have been described in the published English scientific literature, but the French Cochin classification has not been used very much. Its primary advantage lies in its ability to intricately describe the DDH alterations with a large number of grades. We hypothesized that the inter- and intra-observer reproducibility of the SOFCOT-modified Cochin classification system was equal to that of the Crowe and Hartofilakidis classifications. MATERIAL AND METHODS: Five French orthopaedic surgeons who were DDH experts classified 94 A/P pelvis radiographs (179 hips) using the Crowe (Cr), Hartofilikadis (Ha) and modified Cochin (Co) systems. This evaluation was repeated a second time one month later. The intra-observer reproducibility was determined with weighted Kappa and concordance coefficients. The inter-observer reproducibility was performed by calculating the multirater Kappa coefficient on each of the two data series. RESULTS: For the intra-observer reliability, the average weighed concordance coefficients (95% CI) were 88.62-94.52 for Cr, 89.43-93.80 for Ha and 92.14-95.71 for Co. The average weighed Kappa coefficients (95% CI) were 0.70-0.85 for Cr, 0.67-0.82 for Ha and 0.75-0.83 for Co. For the inter-observer reliability, the Kappa for each assessment round was 0.57 and 0.48 for Cr, 0.43 and 0.44 for Ha, and 0.43 and 0.37 for Co. DISCUSSION: The intra- and inter-observer reliability for the modified Cochin classification system is the same as the one for the Crowe and Hartofilakidis classifications. The theoretical advantage of this classification system should be confirmed by comparing the findings with intra-operative anatomical observations. LEVEL OF PROOF, TYPE OF STUDY: IV.
INTRODUCTION:Developmental dysplasia of the hip (DDH) leads to multiple treatment challenges during adulthood. Surgical treatment is mainly based on radiographic evaluation of the anatomical alterations. Several classification systems have been described in the published English scientific literature, but the French Cochin classification has not been used very much. Its primary advantage lies in its ability to intricately describe the DDH alterations with a large number of grades. We hypothesized that the inter- and intra-observer reproducibility of the SOFCOT-modified Cochin classification system was equal to that of the Crowe and Hartofilakidis classifications. MATERIAL AND METHODS: Five French orthopaedic surgeons who were DDH experts classified 94 A/P pelvis radiographs (179 hips) using the Crowe (Cr), Hartofilikadis (Ha) and modified Cochin (Co) systems. This evaluation was repeated a second time one month later. The intra-observer reproducibility was determined with weighted Kappa and concordance coefficients. The inter-observer reproducibility was performed by calculating the multirater Kappa coefficient on each of the two data series. RESULTS: For the intra-observer reliability, the average weighed concordance coefficients (95% CI) were 88.62-94.52 for Cr, 89.43-93.80 for Ha and 92.14-95.71 for Co. The average weighed Kappa coefficients (95% CI) were 0.70-0.85 for Cr, 0.67-0.82 for Ha and 0.75-0.83 for Co. For the inter-observer reliability, the Kappa for each assessment round was 0.57 and 0.48 for Cr, 0.43 and 0.44 for Ha, and 0.43 and 0.37 for Co. DISCUSSION: The intra- and inter-observer reliability for the modified Cochin classification system is the same as the one for the Crowe and Hartofilakidis classifications. The theoretical advantage of this classification system should be confirmed by comparing the findings with intra-operative anatomical observations. LEVEL OF PROOF, TYPE OF STUDY: IV.