Imaging of glenohumeral osteoarthritis: Reliability and reproducibility of radiological classifications

Abstract

Background: Glenohumeral degenerative joint disease may affect up to 20% of the population. There are several classification systems of this disease in the scientific literature.

Objective: The aim of this study is to determine the reliability and reproducibility of glenohumeral osteoarthritis classification systems.

Methods: We assessed glenohumeral plain radiographs performed in a University Hospital. These radiographs were graded into nine radiological classification systems by two observers on two evaluations. Patients who have performed CT/MRI scan were staged according to the Walch classification. The intra-observer and inter-observer reliability of the classification schemes were determined by using Cohen's weighted kappa coefficient.

Results: A total of 752 patients were included in the study (52.4% females and 47.6% males), mean aged 66.2 ± 16.3 years. The intra-observer and inter-observer reliabilities were 0.543 (observer 1), 0.630 (observer 2), and 0.760 (inter-observer) for the Weinstein grading system; 0.661, 0.706, and 0.761 for the Guyette grading system; 0.575, 0.679 and 0.704 for the Kellgren and Lawrence classification; 0.817, 0.816 e 0.871 for the Samilson and Prieto classification; 0.791, 0.811 and 0.847 for the Allain modification; 0.797, 0.842 and 0.860 for the Gerber modification; 0.773, 0.827 and 0.828 for the Buscayret modification; 0.584, 0.648 and 0.755 for the Hawkins and Angelo classification; 0.661, 0.749 and 0.764 for the Rosenberg classification. Intra-observer reliability for MRI was 0.757 (observer 1) and 0.675 (observer 2), while intra-observer reliability for CT was 0.811 (observer 1) and 0.653 (observer 2). Inter-observer reliabilities were 0.790 for MRI and 0.673 for CT.

Conclusion: The classification systems according to Weinstein, Guyette, Hawkins and Angelo, Rosenberg and the modifications of the Samilson and Prieto classification according to Allain, Gerber and Buscayret showed a comparable reliability with the commonly used glenohumeral osteoarthritis grading systems, Samilson and Prieto and Kellgren and Lawrence. Thus, they are recommended for clinical and especially scientific purposes.

Keywords: CT/MRI scan; Shoulder; Walch classification; glenohumeral osteoarthritis; radiological classifications.

Figure 1.

Female patient, left shoulder X-ray performed at age 85. Wenstein classification, stage 4. Guyette classification, stage 3. Kellgren and Lawrence classification, grade 4. Samilson and Prieto classification, grade 3. SPA classification, grade 4. SPG classification, grade 3. SPB classification, stage 4. Hawkins and Angel classification, severe degree. Rosenberg classification, severe degree.

Figure 2.

Female patient, CT scan of right shoulder performed at age 85. The image shows a posterior subluxation of the humeral head, sign of a damaged rotator cuff and consequent eccentric glenohumeral osteoarthritis. The posterior erosion of the glen is responsible for its biconcave shape. Walch classification, category B2.