Animal models of diabetes-related shoulder disorders.

Diabetic shoulder pathology constitutes a significant complication of diabetes mellitus, characterized by complex pathological mechanisms and a lack of systematic research models. Existing animal models can simulate pathological processes such as frozen shoulder, rotator cuff repair impairment, or natural degeneration at different levels, yet they exhibit certain limitations. These include inconsistency with the metabolic background of human type 2 diabetes, a lack of dynamic observation of multi-tissue collaborative pathologies, and difficulty in replicating the natural clinical disease course. This article analyzes three mainstream animal models: the diabetes-combined frozen shoulder model, the diabetes-combined rotator cuff injury and repair model, and the type 2 diabetes-induced natural degeneration model of the rotator cuff tendon. By comparing the modeling methodologies, pathological features, advantages, and disadvantages of these different models, potential improvements are proposed. An ideal diabetic shoulder model should simultaneously replicate the metabolic characteristics of type 2 diabetes, simulate the progressive and collaborative pathology of multiple shoulder structures (tendon, joint capsule, subchondral bone), and incorporate behavioral assessments for pain and functional impairment. Promoting a paradigm shift in animal models from "single-disease simulation" to "integrated simulation" will provide an important platform for elucidating the pathogenesis of diabetic shoulder and developing novel therapeutic strategies.