We present 3 cases of patients with rheumatoid arthritis who developed spontaneous fracture of the femoral neck within 3 months after total knee arthroplasty (TKA) . One patient had bilateral spontaneous fracture of the femoral neck after bilateral TKA. All the patients were female, with osteoporosis, aged from 57 to 68. Before TKA, they had severe limitation of walking, due to knee pain, for several months. Postoperatively, they gained pain relief and recovery of walking ability with a cane.
Osteoporosis and increased walking activities after TKA are thought to be the main etiologic factors for the fractures. When TKA is done in patients with osteoporosis and a prolonged limitation of walking, gradual return to full weight bearing and daily activities should be considered, to prevent spontaneous fracture of the femoral neck that occurs in about 1 % as a complication after TKA.
