KICKING THE TIRES Shop for C-arms with the smallest footprint that provide the clearest images and at the lowest price.

Fluoroscopic imaging is a fundamental component of orthopedic surgery, especially as the specialty's minimally invasive techniques continue to evolve. If your facility is considering acquiring a C-arm or upgrading its current unit, here are 5 factors to keep in mind.

THE BIG PUSH The C-arm is perhaps the bulkiest, heaviest item in your OR. But is it easily mobile?

1. Image quality
The quality of the captured image is without question the most important basis for comparison in choosing a C-arm. If you haven't shopped for a C-arm in the past decade — and this may be a distinct possibility, since this equipment is built and purchased for long-term use — you're likely to find that the machines are able to capture higher-quality images now, even while using less radiation.

Higher-resolution images for a more accurate picture are definitely a boon to clinical outcomes. To cite a small but critical example, fluoroscopic guidance can offer a surgeon assurance that shoulder fracture fixation screws are not only in the right place, but flush with the bone. An imaging system with features that let surgeons easily manipulate images — to move the image up, down, left or right, to zoom in and to measure anatomy — is also a plus.

The key here, and something you'll want to make sure of in trials in addition to admiring the sharpness of a C-arm's image, is that the unit is easy and intuitive to use even if your facility doesn't have radiology techs operating it. Look for pre-programmable settings for your physicians' preferred imaging parameters, for example. Employing an X-ray technician on staff is ideal, but case volume and cost-effective budgets may rule this option out.

2. Scanning safely
Physicians who routinely use and are frequently within close range of fluoroscopic imaging equipment tend to be more cognizant of radiation exposure and the potential risks of its cumulative effect over time. They know they have to X-ray sparingly in order to protect patients, staff bystanders and themselves, so techniques and features that limit the amount of radiation exposure are a hallmark of the latest equipment.

While mini C-arms designed for use in scanning extremities and other smaller sites employ less radiation than standard, full-sized C-arms, they can present exposure levels just as high or higher if their X-ray sources are used closer to the body surface — as they might be while scanning larger extremities — and thus create more radiation scatter.

Consult with a medical physicist when installing and maintaining a C-arm. That will not only ensure that your facility is compliant with state regulations over radiological equipment, but will also give you a measurement of the C-arm's radiation dose and a reading of the minimum amount of radiation required to deliver a sufficiently high-quality diagnostic image for your surgeons' use. A medical physicist may also be necessary to perform periodic safety evaluations.

Reducing radiation exposure is oftentimes a function of how the C-arm is used. An arm that's large enough to accommodate safe positioning (see "Reducing Radiation Exposure") is one important aspect, as is a laser-sight that can confirm where the X-ray beam is focused before it's turned on. Settings that enable pulsed images instead of continuous live imaging can help to reduce the dose of radiation delivered. The radiation safety maxim "As Low As Reasonably Achievable" (ALARA) backs the sacrifice of a small amount of image resolution in exchange for less exposure. You don't need the absolute sharpest image every time, and settings on currently available C-arms will let you reduce exposure while still achieving a good picture.

3. Image management
In early versions of the C-arm, the output and storage of captured images was limited to basic options. A monitor screen was standard for image display, and users were able to save images locally to a built-in hard drive. Transferring images meant printing them through peripheral equipment to paper or X-ray film, or saving them to a 3.5-inch floppy disk (remember those?).

Today's C-arm models can burn images to compact discs or digital video discs, or save them to removable USB flash drives, just for starters. Every arthro-scopy video tower supports these easily portable, universally transferable media for storage: Why shouldn't C-arms?

If your facility is networked, your network servers provide sufficient storage and you're looking to expand into paperless charting, connectivity is the feature to look for when considering C-arms. The ability, and compatibility, to integrate with electronic medical records, practice management software or picture archiving and communication systems (PACS) allows for the digital storage and transfer of captured images. Then they can be accessible and available to physicians in the OR, at workstations throughout your facility, at their office desktops or even on mobile devices for consultations with patients.

4. Size and mobility
The case mix that your facility hosts will be the chief influence over whether you purchase a full-sized mobile C-arm or a more compact mini C-arm. As mentioned, mini C-arms are designed predominantly for imaging patients' extremities, while larger C-arms can accommodate any part of the body, and also can be put into service for pain management and urology procedures. Whichever size C-arm you choose, make sure the arm is sufficiently large enough to fit around your surgical table (which should be radiolucent and imaging-capable) as well as your largest patients.

Don't forget that the C-arm is quite possibly the heaviest, bulkiest piece of equipment you'll be dealing with in your facility. Since it will have to fit the space limitations afforded by your already-technologically-crowded ORs — and whatever storage space you can find in which to park it — look for a machine with a smaller footprint. Newer models are in general smaller and lighter, due to the wholesale adoption of flat-panel over cathode-ray-tube monitors and a reduction in the size of the radiation component.

Remember, too, that the C-arm is a mobile device, both during a case and between them. Your case volume and schedule demands will determine how many you have on site, but if you purchase only one, it might be put to use in different operating and procedure rooms. While it's not the first thing you think of when discussing cutting-edge fluoroscopic technology, keep maneuverability in mind when testing out the devices. How easily can it be moved around the table? Can it be easily maneuvered through the corridors without the risk of damage to the equipment or injury to employees?

5. Counting the cost
A new C-arm might cost you $130,000 on average, which may seem like a bit of a shock no matter how big your equipment budget is. But the devices are workhorses, and a considered purchase tends to deliver what you paid for, especially when it's time to replace one that's nearing the end of its useful life.

You'll know it's time replace your old model when the imaging arm is constantly moving and doesn't lock as solidly when positioned at different angles, or when the foot-pedal control sticks, or when users' complaints aren't resolved even after a round of service. You and your surgical team will notice the significant advances in the available technology, and an upgrade will seem more and more appealing.

Even if the cost of an upgrade beats the mounting repair costs of an aging C-arm, it's still a major expenditure. Make a realistic assessment of your equipment choices based on your budget and potential use of the C-arm before manufacturers' representatives bring the latest options in for trial. If your center doesn't have deep pockets, opt for basic models over those extravagantly outfitted with additional features. Consult with other facilities that have recently replaced their C-arms for a sense of the most useful functions for the price.

While you're considering your choices and planning the financing, be sure to give some thought to the future care of the equipment. A service contract for routine required maintenance is essential. Ask references for insights on the reliability of the manufacturer's service, especially in unanticipated situations, since C-arm downtime can bring a surgical schedule to a halt and leave your ORs idle. Also, a C-arm that can accommodate on-the-fly software, hardware and memory upgrades as they are developed can keep your equipment on the cutting edge even as it ages.