Chronic renal failure due to amyloid nephropathy caused by chronic infection after total hip replacement

A 75-year-old woman was admitted to our hospital because of proteinuria, pitting edema on the foot, and renal impairment. She had undergone total hip replacement (THR) for femoral neck fracture at the age of 66. Nine years later, she met with an accident during farming and was treated at an emergency hospital for severe general trauma. On the basis of systemic symptoms, she was diagnosed with nephrotic syndrome. Renal biopsy by Congo-red staining and electron microscopy revealed amyloid deposition on glomeruli, interstitium, and interlobar arteries. The amyloid was immunohistochemically identified as AA amyloidosis. The patient eventually required maintenance hemodialysis because of impaired renal function. AA amyloidosis is an unusual complication of intractable inflammation. Chronic infection with abscess occurred around the artificial hip joint following THR and possibly induced secondary amyloidosis. THR is a common and necessary procedure adopted for femoral neck fracture. Orthopedic surgeons should, however, carefully monitor the occurrence of chronic infection after THR because such an infection could lead to renal dysfunction and/or failure via AA amyloidosis in rare cases.