INTRAMEDULLARY PRESSURE DURING REAMING AN D NAILING OF THE FEMUR WITHMODERN COMPRESSION INTERLOCKING NAILS - A POTENTIAL CAUSE OF FAT-EMBOLISM

Fat embolism syndrome occurs in only 0.9-4% of patients with long bone fractures and especially with intramedullary nailing. Earlier publica tions have shown that intramedullary manipulation, e.g. reaming and na iling, can produce high pressures of up to 1 bar. The design of the ne w non-slotted interlocking compressions nails seems to increase the pr essure in the femoral cavity. We measured the intramedullary pressure during reaming of the marrow cavity and insertion of compression nails (OSTEO), using cadaver femora and a piezo pressure transducer. We sim ulated a proximal fracture and performed 30 drilling and 20 nailing pr ocedures. On average we detected a maximum pressure of 0.26 bar during drilling and 0.63 bar during nailing. During reaming the pressure inc reased when the reamer had passed the narrow diaphysis and reached the metaphysis. When the tried to enlarge the femoral canal by pushing an d pulling the reamer repeatedly we measured high pressure peaks. Durin g nailing we detected short impulses lasting a few milliseconds. The r esults show that the new compression nail do not produce higher intram edullary pressure than slotted nails. It is possible to avoid a danger ous pressure level by using a careful operative technique.