I was first introduced to digital motion x-ray while attending a whiplash trauma seminar series by Art Croft, DC. Dr Croft, an expert in managing and documenting personal injury (PI) cases, showed how digital motion x-ray is an excellent tool for objectifying injuries, and I was also impressed with trial presentations of digital motion x-ray. I was intrigued, but I needed to do my due diligence as to the research and application of digital motion x-ray.

What is digital motion x-ray? Simply stated, digital motion x-ray is a fluoroscopy-based x-ray system, coupled with digital and optic technology, allowing clinicians to view the spine and extremities in real-time motion at 30 x-rays per second. The procedure is performed with the patient standing and actively moving in a weight-bearing position within the system. The radiation dose to the patient is greatly reduced due to the advancements in digital technology. In addition to decreased radiation, the image quality is crystal clear.

Subtleties Not Missed

The beauty of the technology is that injuries that are missed on plain film x-ray, CT scans, and MRI are very evident using digital motion x-ray. At 30 x-rays per second, a standard cervical series will consist of 2,700 to 3,000 images in real time. With that level of specificity, subtleties are not missed.

Ligamentous injuries are the most commonly overlooked injuries in the PI arena. Research tells us that the thin ligaments in the neck and facet joints are very susceptible to injury.^1–3 Ligament injuries have three common characteristics: They are painful, they are progressive, and they are permanent. A cervical digital motion x-ray study will evaluate 22 ligaments in the neck—the anterior longitudinal ligament, posterior longitudinal ligament, 10 capsular (five on each side), five interspinous, alar (left and right), accessory (left and right), and transverse.

In the cervical spine, there are no disks in the upper 30%—that area is held together completely by ligaments. Where do most patients with cervical complaints have their pain? The back of the neck, the upper neck, and the head. MRI and plain film do not identify these problems. MRIs are shot from C2–C3 down, and there is no way to diagnose injuries to the facet joints and capsular ligaments.

Pictured is an AP open mouth with lateral flexion showing ligamentous damage to the upper cervical spine.

Advanced Imaging Procedure

Facet joints are the structures that we adjust/manipulate in the course of treating patients. Plain films and MRI do not evaluate these structures. In a standard digital motion x-ray study of the cervical spine, oblique flexion and extension views are taken that evaluate damage to the capsular ligaments, as well as evaluate facet joint jamming and foraminal encroachment, in real time. Patients who demonstrate pain in sclerotogenous patterns, not dermatomal, are often suffering from injuries to the facet joints and capsular ligaments. Due diligence would require evaluation of these sensitive pain-generating structures.

Static x-ray imaging is necessary in patient evaluation and management; tumors, fractures, and dislocations need to be ruled out prior to chiropractic care. Digital motion x-ray is taken in addition to, and not in place of, static x-rays. In the post-trauma patient, static x-rays are usually unremarkable. The truth is, ligamentous injury is commonly present. Flexion extension films commonly used to determine ligamentous injury forces the clinician to surmise from two non-moving x-rays which bones are moving too much. Unfortunately, not all motion is picked up on end range, and only two of the 22 cervical ligaments are evaluated, so less than 10% of the ligamentous structures are evaluated.

Pictured is a sample of a flexion/extension shot of digital motion x-ray showing post-traumatic findings.

Also, post-trauma patients hurt when they move, so digital motion x-ray imaging is an excellent fit for finding the true cause of your patient's pain.

MRI imaging of the post-trauma patient is still considered the "gold standard." The problem with cervical MRI scans is that they leave out the top 30% of the neck, and the pain-generating facet joints are not imaged either. Typical cervical MRI reports do not show significant pathology such as disk herniations and stenosis. The majority of positive findings will be bulging disks. When insurance companies try to correlate that a negative MRI proves that a person is not injured (a common practice in PI cases), I simply state that my patient suffers from posterior neck pain, upper neck pain, and headaches, and these are sequelae of ligament injuries—not disk or spinal cord injuries—so I expect the MRI to be negative.

Clinical guidelines set forth by the American Chiropractic Association, International Chiropractors Association, Mercy Guidelines, and Medicare all support the use of fluoroscopy/digital motion x-ray for patient management. Glynna Rangel, DC, DACBR, president of the American Chiropractic Association's Council on Diagnostic Imaging, stated to me: "Digital motion x-ray/videofluoroscopy has proven itself to be the best imaging modality for demonstrating objective evidence of ligamentous instability. It far surpasses conventional radiography in depicting soft-tissue damage affecting the upper cervical spine, facet articulations, and intersegmental dysfunction. Numerous times I've interpreted motion x-ray/fluoroscopic studies demonstrating instability of articulations on patients whom plain film radiography was unremarkable."

The medical community embraces the use of digital motion x-ray imaging as well. The text Pain Management: A Practical Guide for Clinicians by the American Academy of Pain Management states; "Digital motion radiography is currently a valuable diagnostic method in evaluating painful hypermobility and instability due to post-traumatic and degenerative pathology of capsular and axial ligaments."⁴ The American College of Occupational and Environmental Medicine (ACOEM) states in its text Occupational Medicine Practice Guidelines (Volume 2, 2004): "… if probable ligamentous injury with persistent pain, consider fluoroscopically directed flexion study."⁵ The Guides Newsletter by the American Medical Association states: "Evaluation of the cervical spine motion using fluoroscopy or cineradiographic techniques has been described in the literature as being more sensitive in evaluating subtle abnormal motion in the cervical spine."⁶

Digital motion x-ray has been well received by legal professionals as well. By incorporating digital motion x-ray findings in their presentation of facts to insurers, attorneys are finding settlements to be much more reasonable due to the fact that the digital motion x-ray findings provided an objective measurement of their client's injury. When a PI case reaches trial, the use of digital motion x-ray is an effective tool to demonstrate injuries to a jury due to its clarity and simplicity. It is easy to demonstrate what an injury looks like to a layperson, whereas other imaging methods (MR/CT) are difficult for a non-professional to understand. Some attorneys will not litigate a case unless a digital motion x-ray has been performed on their client. They demand a true representation of their client's injuries.

Pictured is a patient positioned for a digital motion x-ray.

The equipment I use is manufactured by DMX Works Inc, located in Palm Harbor, Fla. The clarity and quality of images was superior. Another reason for my choice of equipment is that DMX Works Inc is an active supporter of the chiropractic profession.

Digital motion x-ray has been a great addition to my diagnostic acumen. The majority of cases I image are cervical spine (75% to 80%), followed by TMJ, wrist, lumbar spine, shoulder, ankle/foot, knee, and elbow. I can evaluate patients, and with certainty, explain their injuries and provide a treatment plan that will get them back on the road to normalcy. Additionally, digital motion x-ray has given me the opportunity to network with many chiropractic, medical, and legal professionals by being a valuable resource for them as well.

Ed Harkins, DC, practices in Long Beach, Calif. Contact him at .

References

1. Maak TG, Tominaga Y, Panjabi MM, Ivancic PC. Alar, transverse, and apical ligament strain due to head-turned rear impact. Spine. 2006 15;31(6):632–638.
2. Panjabi MM, Ivancic PC, Maak TG, Tominaga Y; Rubin W. Multiplanar cervical spine injury due to head-turned rear impact. Spine. 2006; 31(4):420–9.
3. Panjabi MM; Maak TG; Ivancic PC; Ito S. Dynamic intervertebral foramen narrowing during simulated rear impact. Spine. 2006; 31(5):E128–34.
4. Weiner RS, ed. Pain Management: A Practical Guide for Clinicians. 6th ed. Boca Raton, Fla: CRS Press; 2001:395-396.
5. Occupational Medicine Practice Guidelines: Evaluation and Management of Common Health Problems and Functional Recovery in Workers. Elk Grove Village, Ill: American College of Environmental Medicine; 2004:184.
6. Luers PR. Motion analysis of the cervical spine. The Guides Newsletter. September/October 2004.