Siemens mobile C-arm adds dimension to orthopedics market

3-D capability promises increased surgical precision

The first production units of Siemens’ new mobile C-arm with 3-D imaging capability will arrive in the U.S. next month. The Siemens sales force will initially target orthopedic and trauma surgical suites, although they plan to sell the system into pain management and sports clinics.

The product’s primary selling point will be 3-D data acquisition. Although some stationary C-arms tailored for such cardiac applications as angiography also acquire and reconstruct data in three dimensions, the Siremobile Iso-C 3D is the first mobile system to offer this capability. It’s made possible by the isocentricity of the C-arm’s design, according to Lynne Groves, surgery product manager for Siemens.

”The x-ray tube and the image intensifier are set within the ‘C’ instead of on the ends,” Groves said. As a result, you can rotate the C-arm around the patient and the anatomy stays centered.”

Image acquisition occurs during an orbital rotation of 190∫, recording a defined set of projections at fixed steps. From those images, an isotropic 3-D dataset is generated. Multiplanar reconstructions (MPR) or shaded surface displays (SSD) can be executed and visualized.

The 3-D dataset is available within two minutes of the C-arm’s rotation. Patients require no additional preparation and they receive a minimal x-ray dose. Exposure with the Iso-C for a typical exam is less than 30 seconds of low-dose fluoroscopy, Groves said.

The Siremobile Iso-C 9-inch system comes with or without 3-D capability. In its most basic configuration, it sells for about the same price as similarly equipped systems, which typically cost well under cost $100,000. The 3-D capability bumps up the price by about 50%, Groves said. In addition to its availability as a stand-alone product, the 3-D hardware and software are available as an upgrade to existing Siremobile Iso-C 9-inch systems, which were introduced in 1998.

Like Philips Medical Systems, which unveiled a line of mobile C-arm systems earlier this year (SCAN 3/14/01), the Siemens Iso-C is targeted primarily at the orthopedic surgical market. In orthopedics, the advantage of 3-D images is the ability to view anatomically precise reconstructions of joint surfaces near complex fractures, as well as the exact positioning of screws and implants, Groves said.

”We’re not just doing general surgeries anymore,” she said. “And orthopedics isn’t about just putting in a few screws and it’s done. We’re seeing more joint replacements and more advanced devices in the OR that require specific placement and alignment.”

Another advantage is the ability to assess status while still in the surgical suite.

Traditionally, patients undergoing orthopedic surgeries are sent from the OR to CT.

”Instead, with a 3-D-capable C-arm, surgeons can get the information they need at a critical time. They can perform a 3-D dataset and determine that there is encroachment in the joint of a screw, for example, while they are in a position to do something about it-in the OR.”

The added confidence that those images provide means less need for CT follow-up and potentially fewer postoperative complications, Groves said.

”From a management standpoint, it also means better productivity and throughput, because you can get resolution on the status of your surgery prior to closure,” she said.