Intramedullary Pressure in Reamed Femoral Nailing with Two Different Reamer Designs

Abstract

Background and Objective: Reaming increases intramedullary pressure and can cause fat intravasation. A new generation of reamers have been developed to minimize these effects. This prospective consecutive nonrandomized clinical trial compares the intramedullary pressure changes of a modern reamer with a conventional one. Objective was to investigate whether intramedullary pressures are different in the use of a new Howmedica reamer compared to a conventionel AO reamer. Patients and Methods: Intramedullary pressures were measured in the distal femoral fracture fragment at the supracondylar region in nine patients and in the intact femur with an impending fracture in two patients with metastatic disease. Monitoring was carried out in 5 AO and 6 Howmedica intramedullary reaming procedures. Results: Significant differences between the two treatment groups could be shown for 9.5 mm, 10 mm, 10.5 mm, 11 mm and 13.5 mm reamers. Analysis of variance for repeated measurements of all diameters showed signigficant more increase of intramedullary pressure with the use of the AO compared to the Howmedica reamer. No clinical symptoms of fat embolism could be detected in both groups. Conclusions: The intramedullary pressures increased substantially with the use of both reamer designs but the highest peak pressures were measured during the reaming of an intact femur. Intramedullary pressure increased significantly with the AO reamer more than with the Howmedica reamer.