Right now at Pinnacle Orthopaedic Surgery Centers, two of our ASC clients are in the market for a total of three new C-arms. To be sure we end up with the best units for the staff and patients, we have developed a systematic method for evaluating them. Here's how we go about it.

Identify needs
First, we clearly define the specific clinical requirements so that the decision-makers are all speaking the same language as they are evaluating decisions. Typical requirements for a unit that surgeons will use for spinal procedures, for example, may include excellent image quality, a C that accommodates larger patients and angles as freely as possible in all planes, user-friendliness, lots of digital image storage, and a good warranty and service plan.

It is also important to factor in future clinical needs as well as budgetary restrictions. For example, orthopedic extremity surgeons typically prefer the mini C-arms because of their intraoperative maneuverability. However, facility managers who are planning to add pain management and/or spinal procedures within the next three years — both of which require larger units for their bigger C's and better image quality — but cannot afford two units should consider purchasing one large unit. This is precisely what we did at one of our centers. Now, after two years of growth, this facility is in a position to buy a second mini unit just for our hand and extremity specialists.

Gather and compare specs
The next step is to gather all relevant specifications from the major C-arm manufacturers. This includes all specs that relate to the predefined requirements, as well as any unique or special features that the manufacturers tout. This information-gathering process requires a basic understanding of how the specs translate into functionality. For example, you may not find a spec labeled "image quality," but you will find measures of X-ray generator power, monitor resolution and focal spot size — all features that contribute to image quality.

To help us track important features and organize them for easy comparisons between units, we created a C-arm spreadsheet. (See "Comparison of C-Arm Specifications" on page 42 for a sample of several larger units we compared.) Here are some specifications we consider important:

• X-ray generator power. Image quality is a result of numerous technical factors, but the power of the X-ray generator lays the foundation for image quality. The more powerful the unit, the better it can penetrate even deep anatomy.

• C-arm size/movement. On any unit, the more freely the C moves, the better. This lets the surgeon visualize anatomic targets with little or no need to reposition the patient. This is relevant primarily for spinal procedures; specifically, the range of motion in both the arc of the C (AP-to-lateral plane) and the patient's cephalic-to-caudal plane is important.

• Digital image storage. Like many facilities, we are moving away from paper storage. The ability to store images digitally is usually an add-on feature of the C-arm, so the expense may vary by vendor. Importantly, so do the storage capabilities, which can range from 66 to 10,000 images.

• Warranty and service contracts. Clearly, the more thorough the warranty and service contract, the better. A good warranty will cover parts (including glassware) and labor for at least a year and will be a full, rather than a prorated, plan. Of course, the dependability of the machine is foremost, as a warranty becomes less important when you are purchasing a unit from a quality company in the first place. In addition, when it comes to the service contract, ensure that the company can provide a service technician to you within 24 hours to minimize expensive downtime. We also look for a technical support hotline and loaner availability.

• Unique selling features. We objectively evaluate any features that appear to be unique to each unit, because this helps determine if any one unit will truly have an advantage over another. For example, some of our surgeons feel a rotating anode is important because it helps dissipate heat. The manufacturer also claims that this feature lets the unit handle a higher energy output. Our comparison shows that another unit we are considering permits 30 minutes of fluoroscopy time before it shuts down to prevent overheating, which may be sufficient if we don't plan to log 30 minutes of fluoro time in one day. Another example of a unique selling feature is "isocentricity," which means the unit always pivots about a central anatomic target, thereby obviating the need to reposition the patient or C-arm regardless of C position. By understanding these features in the context of what the other units have to offer, we can better determine if they have clinical value in our hands when we take the next step, which is to demo our top two or three units.

Demo top units
Next, we meet with our primary end-users and evaluate the spreadsheet to determine which two or three units to demo. Without question, trying the C-arm out during an actual procedure is the best way to evaluate any unit for user-friendliness and image quality. This method allows for interaction with the sales rep as well, so the physicians and staff can understand the unique features of the particular unit.

Majority rules
The next step is to take a majority vote, usually accomplished after significant discussion about the models under scrutiny.

Since many models on the market offer similar quality and features, the deciding factor may come down to surgeon and staff comfort level. This is an important time to review the features you identified as group preference and the performance of those features as they relate to practice needs.

For instance, do you prefer a touch screen? Do you like the idea of having a counterbalanced C-arm to eliminate the need to unlock and re-lock every joint? You should review and evaluate each feature before the vote.

Negotiate price
Wait until you've selected the model before negotiating the price and service contract. Prices are mostly comparable among the high-end units, especially when the digital add-on packages are included. Prices are almost always negotiable. It's more important to first get the features you want. Then you can turn your attention to negotiating an acceptable price.

We consider the purchase of a new C-arm to be a five-year investment because experts tell us that this is the expected life of the X-ray tube, which is a primary and expensive component of any unit, and because capital equipment is usually depreciated over a five-year period. By approaching this purchasing decision in a step-by-step fashion, you can better ensure that those five years will bring smooth sailing for fluoroscopy needs in your ORs.