Cardiac arrest during hip arthroplasty with a cemented long-stem component. A report of seven cases. Seven patients had a cardiac arrest during hip arthroplasty with a cemented long-stem femoral component. Four patients died in the operating room, and three patients were successfully resuscitated. When the three survivors were eventually discharged from the hospital, they had no known permanent cardiac, pulmonary, or neurological sequelae. Factors that were common to all of the patients were advanced age, osteoporotic bone, a previously undisturbed intramedullary canal, and use of a long-stem femoral component and several batches of methylmethacrylate. Hip arthroplasty with a long-stem femoral component is associated with substantial risk in these patients. Excessive pressurization of cement should be avoided, and invasive hemodynamic monitoring should be used when the described conditions are present. 