P20 COMPARISON OF PRESSURES GENERATED BY VARIOUS INTRAMEDULLARY REAMERS IN USE IN THE NHS TODAY

Abstract

Reamed, locked intramedullary nailing is the treatment of choice for many long bone fractures, be them open or closed injuries. Certain nails used can be inserted without any locking component or reaming. However, the most biomechanically sound fixation is achieved with a reamed, locked nail, and this therefore is the preferred construct. The process of reaming is not without complication, however. Pulmonary complications secondary to embolization of intramedullary contents are of the most concern. The formation of emboli is believed to be a direct result of raised intramedullary pressures created largely by the reaming process, although nail insertion does also play a part.

The magnitude of intramedullary pressures generated during the reaming process is due, in part, to the design of the reamer itself. This study compares four different reamers currently in use in NHS hospitals today. The reamersusedincludeanolderdesign(AOUniversal(TM)) and three newer designs (Synthes Synream(TM), Biomet 5+(TM) and Stryker Bixcut(TM)).

Four different reamer head sizes were used- 9.5mm, 11.5mm, 13.5mm and 15.0mm. These were tested in vitro using a Vaseline(TM)/paraffin oil mixture to simulate intramedullary tissue and Perspex(TM) tubing of varying sizes to simulate a long bone with an intramed-ullary cavity.

The results showed that the older generation reamer produced consistently higher pressures than the newer designs of reamer with statistical significance. All the newer generation reamers produced similar pressure magnitudes, although the Biomet 5+(TM) tended to produce the lowest pressures with some statistically sig-nificant differences.

This study shows that different designs of reamer can generate different pressures and that the newer generation of reamers do produce lower pressures. This is therefore important in the prevention of complications associated with reaming and intramedullary nailing.