Intramedullary pressure changes in reamed and unreamed nailing systems: an experimental study in cadaveric femoral bones

Oh, Chang Wug; Ihn, Joo Chul; Kim, Poong Taek; Park, Il Hyung; Kim, Sung Jung; Lee, Chung Hyun

Abstract

PURPOSE
This study was designed to investigate whether intramedullary pressure is different in reamed compared with unreamed femoral nailing in cadeveric femoral bones. MATERIALS & METHODS: Eight pairs of fresh-frozen cadaveric femoral bones were studied. The diameter of isthmus was checked from 10mm to 14mm and the length of femur was checked from 35cm to 44cm. Intramedullary pressure was measured in the distal femoral shaft at the supracondylar region. Data were monitored in femoral nailing procedures. We utilized the AO universal nail(reamed) and AO unreamed femoral nail.
RESULTS
Intramedullary pressure increased in the reamed group to 423.8 mmHg(mean pressure) during reaming by starting reamer(9 mm) and in the unreamed group to 290 mmHg(mean pressure) during insertion of nails(p=0.001). In the unreamed groups, the next high intramedullary pressure is 136.6 mmHg during proximal reaming. A statistiscally significant difference in intramedullary pressure was found during the first reaming process in the reamed group compared with the proximal reaming process in the unreamed group(p=0.005).
CONCLUSION
The data indicate that the intramedullary pressure during unreamed nailing process is lower than reamed nailing process. So we can consider that the unreamed nailing in multiple fracture or pulmonary injured patients is a good modalities.