Reliability of the modified lateral pillar classification for Legg Calvé Perthes disease performed by a large group of international paediatric orthopaedic surgeons

Abstract

Purpose The modified lateral pillar classification (mLPC) is used for prognostication in the fragmentation stage of Legg Calvé Perthes disease. Previous reliability assessments of mLPC range from fair to good agreement when evaluated by a small number of observers with pre-selected radiographs. The purpose of this study was to determine the inter-observer and intra-observer reliability of mLPC performed by a group of international paediatric orthopaedic surgeons. Surgeons self-selected the radiograph for mLPC assessment, as would be done clinically. Methods In total, 40 Perthes cases with serial radiographs were selected. For each case, 26 surgeons independently selected a radiograph and assigned mLPC and 21 raters re-evaluated the same 40 cases to establish intra-observer reliability. Rater performance was determined through surgeon consensus using the mode mLPC as ‘gold standard’. Inter-observer and intra-observer reliability data were analysed using weighted kappa statistics. Results The weighted kappa for inter-observer correlation for mLPC was 0.64 (95% confidence interval: 0.55 to 0.74) and was 0.82 (range: 0.35 to 0.99) for intra-observer correlation. Individual surgeon’s overall performance varied from 48% to 88% agreement. Surgeon mLPC performance was not influenced by years of experience (p = 0.51). Radiograph selection did not influence gold standard assignment of mLPC. There was greater agreement on cases of mild B hips and severe C hips. Conclusions mLPC has low good inter-observer agreement when performed by a large number of surgeons with varied experience. Surgeons frequently chose different radiographs, with no impact on mLPC agreement. Further refinement is needed to help differentiate hips on the border of group B and C. Level of evidence III

Validation of the height–width measurement in Perthes disease among interpreters of different experience levels

“…Higher experiences tended to increase kappa statistics by 0.042 (−0.066 to 0.150) without statistical significance. Our results were comparable with other studies that have reported intraobserver agreement as kappa 0.48–0.79 in Catterall [12,13], 0.50 in Salter–Thompson [13], 0.68–0.82 in lateral pillar [12,13] and 0.60–0.92 in modified lateral pillar [7,14]. Aforementioned interobserver agreement was 0.44–0.79 in Catterall [13,15], 0.16 in Salter–Thompson [13], 0.39–0.72 in lateral pillar [12,13] and 0.57–0.92 in modified lateral pillar [7,14].…”

“…The height-width ratio demonstrated intraobserver level of agreement from −0.010 to 0.022, and interobserver reliability compared with the paediatric orthopaedist from −0.021 to 0.003. After converting the height-width ratio to the [13], 0.68-0.82 in lateral pillar [12,13] and 0.60-0.92 in modified lateral pillar [7,14]. Aforementioned interobserver agreement was 0.44-0.79 in Catterall [13,15], 0.16 in Salter-Thompson [13], 0.39-0.72 in lateral pillar [12,13] and 0.57-0.92 in modified lateral pillar [7,14].…”

“…After converting the height-width ratio to the [13], 0.68-0.82 in lateral pillar [12,13] and 0.60-0.92 in modified lateral pillar [7,14]. Aforementioned interobserver agreement was 0.44-0.79 in Catterall [13,15], 0.16 in Salter-Thompson [13], 0.39-0.72 in lateral pillar [12,13] and 0.57-0.92 in modified lateral pillar [7,14].…”

Evaluación de estudio cinemático de la marcha en pelvis y caderas de pacientes con diagnóstico de enfermedad de Legg-Calvé-Perthes en el Hospital Shriners para Niños México

“…Resultados: Se analizaron 22 pacientes, 19 con enfermedad unilateral (86%) y tres con afectación bilateral (14%), los cuales, para fines del estudio fueron considerados con cada cadera afectada como un caso; 25 caderas afectadas en total, cinco caderas de pacientes femeninos (20%) y 20 caderas masculinas (80%). Media de edad 12.8 ± 3.3 años (rango [5][6][7][8][9][10][11][12][13][14][15][16][17]. Lado izquierdo predominante en 15 caderas (60%); 21 casos en fase de fragmentación (84%) y 4 en remodelación (16%).…”

“…Results: Twenty-two patients were analyzed, 19 with unilateral disease (86%) and three with bilateral involvement (14%), which, for the purposes of the study, were considered with each affected hip as a case; 25 affected hips in total, five female patient hips (20%) and 20 male hips (80%). Mean age 12.8 ± 3.3 years (range [5][6][7][8][9][10][11][12][13][14][15][16][17]. Predominant left side in 15 hips (60%); 21 cases in the fragmentation phase (84%) and 4 in remodeling (16%).…”