Dialysis-Related Amyloid Arthropathy (Beta-2 Microglobulin)

The unifying diagnosis is dialysis-related amyloidosis, a beta-2 microglobulin amyloidosis. Beta-2 microglobulin is normally cleared by the kidney but is poorly removed by conventional dialysis, so it accumulates in long-term dialysis patients and forms amyloid fibrils that deposit in osteoarticular tissue; the risk rises with dialysis duration, which fits this 15-year history. The features are classic: bilateral carpal tunnel syndrome, often the first manifestation, from amyloid in the carpal tunnel; a chronic large-joint arthropathy, classically of the shoulder; and subchondral bone cysts, here in the femoral neck, which enlarge over time and predispose to pathological fracture. Related upper-limb features include flexor tenosynovitis and trigger fingers, and there can be a destructive, often cervical, spondyloarthropathy with instability that can mimic infective spondylodiscitis. Management is largely surgical for the complications: carpal tunnel decompression, often bilateral, with tenosynovectomy and trigger-finger release; monitoring of enlarging cysts with curettage and grafting and prophylactic fixation for impending pathological fracture; and stabilisation of a destructive, unstable spine after excluding infection. I would optimise the dialysis with high-flux, ultrapure membranes to slow progression. The only definitive treatment, which removes the source by lowering beta-2 microglobulin, is a successful renal transplant.