Musculoskeletal pain in dialysis-related amyloidosis.

In March 1999, a 49-year-old woman presented with acute right hip pain and no history of trauma. She had been diagnosed with rapidly progressive glomerulonephritis in 1966 leading to complete renal failure in 1973. Treatment included multiple failed attempts at transplantation and long-term hemodialysis. She was diagnosed with beta-2 microglobulin amyloidosis in 1986. She had a parathyroidectomy for secondary hyperparathyroidism, a history of renal osteodystrophy, multiple surgical releases and tenosynovectomies for bilateral carpal tunnel syndrome and trigger finger, and polyarthritis. Radiographs demonstrated a large lytic defect in the right femoral neck. A smaller lytic defect was noted in the left femoral head. As prophylaxis, the patient underwent internal fixation of the right hip with a dynamic hip screw (DHS). Curetted bone taken from the lesion at the time of surgery stained positive with Congo red and exhibited the characteristic dichroism of amyloid. Immunoperoxidase stains for beta-2 microglobulin were also positive. Six months postoperatively, hip discomfort persisted and the patient remained unable to fully weight-bear. Despite a well-fixed pin and plate, the large lytic defect in the right femoral neck was unresolved, and no signs of healing were evident on radiography. In addition, she exhibited diffuse myofascial pain and muscle spasms. This pain was distinct from her bony pain and was especially prevalent in her pelvic girdle. Physiotherapy as well as narcotics, mexiletine, benzodiazepines and systemic xylocaine were tried with some success. Selective serotonin reuptake inhibitors (SSRIs) and antiepileptics were used for a painful femoral neuropathy. In June 2002, the patient developed severe left hip pain, and radiographs revealed an incomplete fracture through the previously identified lytic defect. Open reduction and internal fixation with a DHS was performed. In April 2003, the patient experienced a further increase of her longstanding right hip pain. Radiographically, marked angulation at the inferior aspect of the prosthesis was seen and was attributed to fracture of the proximal femoral shaft. The DHS was removed, and revision with a locked femoral antegrade intramedullary nail was undertaken. Biopsy showed no evidence of amyloid at this fracture site. Investigation of severe right thigh pain postoperatively revealed an intramuscular amyloid deposit, palpable on physical examination. Radiographs in January 2004 showed evidence of healing around the right femoral shaft fracture. Fracture lines at the left hip did not show signs of healing, but at the right hip, the fracture lines showed early callous. See Figure 1 and Figure 2 for radiographs.