Hemodialysis-associated amyloidosis - "bone cysts", femoral neck fractures- findings in hip joint specimens and iliac crest bone biopsies

Hemodialysis is associated with many complications such as renal osteopathy , dialysis-related amyloidosis and aluminium depositions found in the skele ton. The amyloid associated diseases such as destructive arthropathy, destr uktive spondylarthropathy and lytic bone lesions are radiologically detecta ble but their morphological substrate remains unclear. To elucidate the und erlying problem a histological examination is necessary. Lytic lesions caus ed by amyloid depositions in the femur close to the femoral neck accomodate the risk of fracture. This histological study includes 38 resection specim en of the proximal femur of patients with dialysis associated amyloidosis a nd various duration of hemodialysis. The indication for resection was the f racture of the femoral neck. Amyloid depositions were examined relative to their location, their amount and the reaction of the surrounding tissue. Re nal osteopathy as well as aluminium depositions were also taken into consid eration. The aim of the study was to determine the influence of these facto rs on the development of femoral neck fracture. By means of immunohistochem istry beta-2-microglobulin could be detected as the major component of this type of amyloidosis. In 13 cases (30%) amyloid was located in the joint ca psule as well as in the bone. These depositions could clearly be judged as the cause of fracture. This group showed a striking coincidence with renal osteopathy IIIa (p = 0.001) and aluminium depositions (p = 0.0002) as well as a longer period of hemodialysis (14,6 years) in comparison to the cases with amyloid restricted to the joint capsule and cartilage. Additionally on examination of trephine biopsies of the iliac crest from a collective of 1 3000 patients with chronic hemodialysis beta-2-microglobulin depositions co uld be detected within the periosteum in 46 cases. One can conclude that he modialysis associated amyloidosis is one of the main reasons for fracture o f the femoral neck in dialyzed patients and that the risk of fracture may e ven be increased with simultaneous occurence of renal osteopathy with reduc ed bone turnover and aluminium depositions. Dialysis associated amyloidosis can be diagnosed in trephine biopsies of the iliac crest by thorough exami nation and though the interpretation of possible radiological skeletal find ings is improved.