Research Article: Interobserver Reliability among Radiologists and Orthopaedists in Evaluation of Chondral Lesions of the Knee by MRI

Date Published: July 7, 2011

Publisher: SAGE-Hindawi Access to Research

Author(s): Fábio Cavalli, Anela Izadi, Ana Paula R. B. Ferreira, Larissa Braga, Andresa Braga-Baiak, Marco Antonio Schueda, Mihir Gandhi, Ricardo Pietrobon.


Objective. The aim of this study was to evaluate interobserver reliability in the presence of chondral injuries of the knee among radiologists, orthopaedic surgeons, radiologists, and orthopaedic surgeons. Methods. This was a prospective, web-based multi-institutional survey, consisting of 6 magnetic resonance exams of knee chondral injuries and a questionnaire to be completed by the participants. Two radiologists and two orthopaedic surgeons were enrolled, with more than 5 years of clinical experience. Kappa statistics test was used to calculate interobserver reliability between participants. Results. Kappa ranged from −0.13 through 0.29 between orthopaedists; from 0.06 through 0.78 between radiologists; from −0.10 through 0.24 between orthopaedists and radiologists. Cases 3 and 6 had skewed results among radiologists: with Kappa scores of 0.78 and 0.53, respectively. Conclusions. Our study reveals that the interobserver agreement between radiologists is higher than among orthopaedists in the evaluation of chondral knee lesions by MRI.

Partial Text

Advancements in diagnostic imaging and the development of minimally invasive surgical techniques have enhanced the diagnosis of cartilaginous lesions, [1, 2]. Patients with chondral lesions of the knee often present with functional limitations and reduced physical activity, as a result of pain and haemarthrosis [3]. In the United States, mainly because of increased longevity and active lifestyles, more than 39 million physician visits and 500,000 hospitalizations occur each year for the treatment of degenerative articular cartilage diseases [4].

Results are shown in Table 1. Kappa values ranged from −0.13 (no agreement) through 0.29 (fair agreement) between orthopaedists; from 0.06 (slight agreement) through 0.78 (substantial agreement) between radiologists; from −0.10 (no agreement) through 0.24 (fair agreement) between orthopaedists and radiologists. Case  3 and Case  6 had skewed results, with high Kappa values between radiologists: 0.78 (substantial agreement) and 0.53 (moderate agreement), respectively.

The most widely used classification system for chondral damage is the Outerbridge Classification system, which has been described in over 31,000 articles worldwide [14]. To the best of our knowledge, the present study is the first to evaluate interobserver agreement images of chondral lesions of the knee by MRI among orthopaedists, radiologists, and between orthopaedists and radiologists. Overall, our results suggest that there is “fair agreement” between orthopaedists; “fair agreement” between radiologists and orthopaedists; “substantial agreement” between radiologists.




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