Arthroscopic surgery for synovial chondroma of the subacromial bursa with non-traumatic shoulder subluxation complications: Two case reports

Figure 1 Imaging examinations of case one. A: Plain radiograph in anteroposterior view of the right shoulder, showing subluxation of the humeral head; B: Magnetic resonance imaging examination of the shoulder joint, showing multiple intra-articular loose bodies and joint effusion.

Figure 2 Imaging examinations of case two. A–C: Plain radiographs and three-dimensional computed tomography (3D-CT) reconstruction of the left shoulder, showing multiple intra-articular loose bodies and the subluxation of the humeral head; D–F: Postoperative radiographic re-examination and 3D-CT reconstruction showed no loose bodies in the subacromial space. The humeral head returned to a normal anatomical relationship.

Figure 3  Magnetic resonance imaging of the shoulder joint showed multiple intra-articular loose bodies and joint effusion.

Figure 4 Pathological examination of case one. A: Lobulated areas of hyaline cartilage just below the synovial surface were easily identified by hematoxylin-eosin staining (magnification: 20 ×); B: Chondrocytes were found clustered together and were not uniformly distributed throughout the ground substance (magnification: 100 ×).

Figure 5 Pathological examination of case two. A: Fragments of articular cartilage or subchondral lamellar bone were present in loose bodies identified by hematoxylin-eosin staining (magnification: 20 ×); B: Chondrocytes were found in the zonal and ring-like units together and were uniformly distributed throughout the ground substance (magnification: 100 ×).

Figure 6  From the standard posterior portal, the arthroscopic view revealed a large number of cartilaginous loose bodies in the region of the subscapularis.

Figure 7  From the standard posterior portal, the arthroscopic view revealed a large number of cartilaginous loose bodies and synovial capsule hyperplasia, with inflammatory changes in the region of the subscapularis.