» Chronic Charcot arthropathy results from the convergence of genetic predisposition (OPG/RANKL/RANK polymorphisms), metabolic disturbances (AGEs, vitamin D deficiency affecting 84.2% of patients), and inflammatory dysregulation (RANKL/OPG axis, IL-17 family cytokines), explaining why only 0.08-1% of diabetic neuropathy patients develop this devastating complication. Here, TNFRSF11B is linked to vitamin D deficiency.