We will be performing site maintenance on AAOS.org on February 8th from 7:00 PM – 9:00 PM CST which may cause sitewide downtime. We apologize for the inconvenience.

Fig. 1 Picture of patellar component during total knee arthroplasty before and after white balancing. Note how proper white balancing will also improve the skin tone.
Courtesy of Stuart J. Fischer, MD

AAOS Now

Published 2/1/2014
|
Stuart J. Fischer, MD

Bringing a Camera Into the OR

What you should know about taking intraoperative photos

It’s a digital world. As more surgeons transition to electronic medical records (EMR), digital images are taking a greater place in patients’ “charts.”

Surgeons who write or publish are accustomed to taking clinical pictures as well as snapshots of radiographs to include in articles. Modern digital technology has made it easier to take good quality pictures. But bringing a camera into the operating room (OR) can be a challenge. Issues of consent, lighting, color balance, sterile technique, and logistics all need to be addressed. The following tips provide general information—from a surgeon’s perspective—on taking photos in the OR.

Consent
First, it’s important to obtain proper consent. In general, a patient’s permission is required for any picture that contains enough information to enable someone to identify the patient. Every digital camera embeds EXIF (exchangeable image file) data on each photo identifying the time and date the picture was taken, as well as the camera and exposure settings. Assuming the calendar settings in the camera are correct, the patient can be easily identified from this information.

Consent may not be needed if the photo focuses on a small area and the patient cannot be recognized. But many hospitals do require consent, even if you are just photographing a limited area such as a hand or ankle. So be sure to protect yourself and check your hospital rules. The circulator in the room may chart that you have taken pictures.

If your pictures include other members of the OR team, you’ll need their consent as well before you publish the photos.

Color and light
When you are photographing anatomic structures, color accuracy is critical. The lighting in the room determines how colors will appear. Once in the OR, make adjustments for the color temperature and brightness of the OR lights. Colors look different under artificial or fluorescent light than they do in daylight. Traditional cameras require special film to shoot indoors. Digital cameras allow more precise adjustment both before and after taking the picture.

Color accuracy is determined by white balance. It is measured on a color temperature scale (Kelvin degrees) in a range of 2,000K (candlelight) to 10, 000K (shade/overcast skies). Generally speaking lower temperatures have more yellow, higher temperatures more blue. The aim is to adjust the color so that white appears normal (Fig. 1).

Arthroscopists are familiar with the white balance button on the video camera. All digital cameras have automatic white balance (AWB); some have a manual adjustment that will allow you to point the camera at a clear white object and then manually adjust the temperature by degree. OR lights will typically take a setting between 3,200K and 4,400K.

If you have the camera on “auto,” place a bright white object such as a lap sponge somewhere in the field. That way you can also adjust the white balance with software during processing.

In addition to color, you’ll need to think about lighting. OR lights are bright, hang from the ceiling, and are usually positioned directly over the field. If the camera is directly underneath the lights and over the field, a shadow will cover much of the picture (Fig. 2). Direct lighting can also create bright “highlights” or areas of overexposure compared to the rest of the field (Fig. 3). To compensate for this, some cameras will have a “high dynamic range” setting that allows the software in the camera to create a more balanced exposure.

Bringing lights in from opposite sides at a lower angle will minimize shadows and spread the light over a wider area. Or you can turn the lights away and use a flash. A flash, however, may cause unwanted reflections off of liquids or metallic implants in the field.

Another option is a “ring flash,” a circular attachment that fits on the front of the lens. This gives softer, more direct light on a smaller field than a traditional flash and avoids a lens shadow.

It may help to “bracket” the exposure. That is, the camera will automatically take three (or five) pictures at different exposure settings every time the shutter is snapped. This will allow you to choose the picture with the best lighting and is especially helpful if the critical part of the picture is too light or too dark. Bracketing is also very useful if the individual who is taking the pictures doesn’t know how to adjust the settings.

Be aware that surgical skin pre-preparations—as well as the OR lights—can affect the appearance of normal skin tones.

Lens selection
Before you get to the OR, choose equipment that will take the pictures you need and do it quickly. For large fields, such as open hip and knee surgery, a lens with a standard or short telephoto focal length will do the job.

In most situations, however, a macro lens that allows for close focus and a smaller field will be better. A macro lens on a standard DSLR (digital single lens reflex) camera can focus as close as 6 to 8 inches of the field; macro settings on some compact cameras allow you to get within 1 to 3 inches. This will capture fine details at close range.

From a logistical standpoint, holding and focusing a camera at any distance can be difficult. The operating table is at waist level or higher. So whoever is taking the picture will have to hold the camera several inches above the field and be able to look through the viewfinder or at the LCD screen to focus. Unless you have a lens that can focus within a few inches, you (or whoever is taking the picture) will need either to stand on a stool or to lower the table.

Fig. 1 Picture of patellar component during total knee arthroplasty before and after white balancing. Note how proper white balancing will also improve the skin tone.
Courtesy of Stuart J. Fischer, MD
Fig. 2 Direct OR lights on the field can be bright and cause “highlights” as shown above.
Courtesy of Stuart J. Fischer, MD
Fig. 3 Camera shadow seen in lower part of the field.
Courtesy of Stuart J. Fischer, MD
Fig. 4 Cropped macro photograph of median nerve in a 1 cm endoscopic carpal tunnel portal.
Courtesy of Stuart J. Fischer, MD

Beyond this, a bright lens with a wide aperture (low f-stop) will be very helpful in indoor light and let you use a faster shutter speed to eliminate blurring. Image stabilization, a feature on most new cameras and lenses, can also reduce blurring and improve the focus on your pictures.

Camera selection
The camera choice is really the photographer’s preference.

Larger camera bodies will let you use interchangeable lenses and have bigger sensors so there is less “noise” in the picture. But the newer generation of compact cameras provides picture quality that is almost as good and may be smaller and easier to handle in an OR setting. If you are using a compact camera at close range, make sure to set the focus to “macro.”

The number of megapixels you need depends on how big the printed or web image will be. Often you will want to crop or use only a portion of your original image. So for a 4- by 6-inch print or web image at 300 dots per inch, you would need 2 to 3 megapixels. If you are cropping from a larger image, the original would have to be at least 8 or 10 megapixels.

Who snaps the shutter?
Where possible, I recommend that, as the surgeon, you take your own pictures. You know best what needs to be in the picture and you will get the perspective you want. You will also have a more direct angle on the field than someone who is standing behind you or off to the side.

Have a dedicated table or Mayo stand near the field where you can place your camera. Put a towel or sheet over the table so the camera does not slide off the hard metal surface. Do all your settings beforehand so that you can grab the camera, focus, take the picture, and quickly return to the procedure. To maintain sterility, put an extra pair of sterile gloves over your operating gloves when you are ready to pick up the camera. After you take the picture, you can remove the extra gloves and resume the procedure. Be careful not to let the camera or camera strap touch your gown or the operative field.

If you are having someone else take the picture, make sure they understand how to use the camera and what you are looking for in the image.

Editing and processing
Digital photography lets you take multiple exposures and select the best. You can then use software to crop the image and make adjustments such as brightness, sharpening, contrast, and saturation. You can also add arrows or other shapes to identify objects within the picture (Fig. 4).

In general, if you are writing for the public, it is best to leave a wider field to add perspective and, if there is blood in the field, to tone down the saturation on the red colors.

Most cameras automatically process and compress the file size of an image so that it is stored on the camera’s memory card as a standard .jpg image. But one way to achieve more control is to shoot pictures in a RAW format. A RAW image is a “digital negative.” Like a film negative, it is a basic exposure that needs to be processed before the final result can be achieved. RAW files are larger and need to be edited in special software such as Photoshop or Aperture because each camera company has its own RAW file format such as .cr2 (Canon), .sr2 (Sony), or .ORF (Olympus).

Shooting in RAW permits finer image adjustments before the file is compressed. You can fine tune the white balance, color, and sharpening and sometimes recover details from over-exposed areas (highlights) that would otherwise not be visible.

Conclusion
Digital imaging is becoming a bigger part of printed and online publication as well as EMR documentation. Surgeons who are just starting to take photos in the OR should remember the following points:

  • Get appropriate consents.
  • Choose camera equipment that works for you.
  • Check the lighting.
  • Do as much advance setting as possible.
  • Take multiple images.
  • Maintain a sterile technique.
  • Be prepared to do editing and post processing afterward.

Stuart J. Fischer, MD, an orthopaedic surgeon in private practice in Summit, N.J., is a member of the AAOS Now Editorial Board and associate editor of the AAOS patient education website, orthoinfo.org

Learn More about Video at the Annual Meeting
Using a still camera is one thing; taking a surgical video is something else. Videos are a great way to show how to perform orthopaedic surgical techniques, and orthopaedists can both publish and view orthopaedic videos in a great many venues.

A free Faculty Development course at the AAOS 2014 Annual Meeting can teach you how to create award-winning orthopaedic videos. Offered on Wednesday, March 12, 1:30 p.m.–3:30 p.m., in room 217 of the Morial Convention Center, “Video Production for the Orthopaedic Surgeon: Getting the Award, Making the Difference” will also present information on how to critically evaluate orthopaedic technique videos.

Moderator Kevin D. Plancher, MD, MS, is the current chair of the AAOS Multimedia Education Subcommittee; faculty member Cesare Faldini, MD, has produced several award-winning videos.

At the Electronic Skills Pavilion (Booth 5463 in the Technical Exhibits Hall), you can learn how to take your video from camera to PowerPoint. On Friday, March 14, at 1:30 p.m., Randipsingh R. Bindar, MD, will present “Movies Speak a Million Words: Take Your Movie from Camera to PowerPoint.”

This live demonstration will show you the key steps of editing and encoding captured video into a slick movie that can be inserted into a PowerPoint presentation. The Electronic Skills Pavilion showcases current technology, products, and application for orthopaedic surgeons. Presentations are free; check www.aaos.org/exhibits for a complete schedule.