To investigate the role of VEGF (vascular endothelial growth factor) and macrophage cells in the pathogenesis of diabetic frozen shoulders.

Five diabetic frozen shoulders which were resistant to conservative treatment were involved in this study. Synovial tissue was obtained during arthroscopic adhesiolysis. The synovial tissue of the shoulders from cadava dominators who had no history of shoulder joint disease was used for the control study. Immunohistochemical staining was performed with polyclonal antibodies against VEGF and CD68 macrophage/synovial antigen.

Injection and hypertrophy of the synovium and thickening of the capsule were noted in all diabetic frozen shoulders. Strong immunostaining to VEGF and CD68 was observed in all diabetic frozen shoulders, whereas the control specimens showed little staining.

From these results it would be postulated that the VEGF, synthesized and secreted by macrophage/synovial cells of the diabetic frozen shoulders stimulate regional angiogenesis which leads to synovitis and fibrosis could be one of the leading factors in the pathogenesis of frozen shoulders in diabetic patients.