Rapidly destructive arthropathy of shoulder joint

Background: Rapidly destructive arthropathy (RDA) of the shoulder is rare. Consequently, there are very few studies that have reported the characteristic findings of this disease. This study aimed to analyze the clinical, radiographic, and histologic features of patients with RDA of the shoulder. Methods: In total, 9 cases (8 patients) were enrolled in this study. All patients were elderly women, with a mean age of 72.7 years (range, 57-78 years). The mean duration of symptoms was 4.1 months (range, 1.2-5.9 months). Reverse total shoulder arthroplasty and total shoulder arthroplasty were performed in 5 cases with massive rotator cuff tears and 4 without them, respectively. Results: The mean duration of radiologically evident joint destruction after negative results on radiography was 3.1 months (range, 1.0-5.9 months). On plain radiography, humeral head flattening and collapse that appeared like cut grass were observed (100%). Relatively good preservation of the glenoid with a normal joint space was observed in 7 cases, whereas glenoid erosion was observed in 2 (22.2%). T1-weighted magnetic resonance imaging showed a subchondral fracture (100%) of low signal intensity with associated bone marrow edema. Histologically, chronic inflammation of the synovium and osteocytes in the lacunae, as well as callus formation, were observed along the subchondral fracture. Conclusion: Flattening and collapse of the humeral head within an average of 4 months of symptom onset are characteristic of RDA of the shoulder. Bone marrow edema, joint effusion, and subchondral fracture on magnetic resonance imaging and fracture fragments and callus formation on histopathologic analysis were observed. Glenoid erosion was observed in 2 cases with arthrosis progression.