An episode of hypotension is common during cemented joint replacement, and has been associated with circulatory collapse and sudden death. We studied the mechanism of hypotension in two groups of six dogs after simulated bilateral cemented arthroplasty. In one group, with no lavage, the insertion of cement and prosthesis was followed by severe hypotension, elevated pulmonary artery pressure, decreased systemic vascular resistance and a 21% reduction in cardiac output. In the other group, pulsatile intramedullary lavage was performed before the simulated arthroplasties. Hypotension was less, and although systemic vascular resistance decreased, the cardiac output did not change. The severity of the hypotension, the decrease in cardiac output and an increase in prostaglandin metabolites were related to the magnitude of pulmonary fat embolism. Pulsatile lavage prevents much of this fat embolism, and hence the decrease in cardiac output. The relatively mild hypotension after lavage was secondary to transient vasodilation, which may accentuate the hypotension caused by the decreased cardiac output due to a large embolic fat load. We make recommendations for the prevention and management of hypotension during cemented arthroplasty.

The hospital records of 222 cases of ipsilateral fractures of the femur and tibia were reviewed, and patients were grouped according to the type of fracture and the method of treatment. Thirty-five per cent of patients required late operation for delayed union or non-union, osteomyelitis, refracture and malunion, regardless of the treatment group. A disturbing factor was the 30% incidence of osteomyelitis in patients treated by fixation of both fractures, almost three times the incidence when only one fracture was fixed. A 30% incidence of delayed union or non-union occurred in patients managed conservatively. Of sixty-three patients personally examined, the worst results found were those following conservative management of both fractures. More use of rigid external fixation and of cast bracing is recommended in the management of the fractured tibia, combined with internal fixation of the femoral fracture. Examination of the knee suggested that, with ipsilateral fractures, disruption of ligaments is a common occurrence and should always be suspected.