Radiographic assessment and determination of joint subluxation have been an integral part of chiropractic evaluation since the early 1900s.335,460,461 Ever since Sausser first made a full-spine exposure,
the chiropractic profession has desired and sought out methods for marking x-ray films to identify manipulable lesions. The history of chiropractic marking procedures dates back to 1910462 when it
was first introduced in the Palmer School curriculum.
The early use of diagnostic x-ray examinations in the chiroprac- tic profession centered on the assessment of biomechanical relation- ships and the measurement and description (listing) of spinal joint malpositions. To that end, the profession and many of its individual technique innovators have developed specific radiographic measure- ment techniques (spinography) designed to quantify and classify spi- nal malpositions and subluxations (Figure 3-31).32,128,461,463-467
Although many “systems” to detect static subluxations on x-ray films have emerged over the years, these procedures remain con- troversial. Criticism and failure of the static x-ray marking systems come from trying to use quantitative measures on landmarks that vary and that are subject to geometric distortion.468 Moreover, the
spine and its functional units are living, moving, and dynamic struc- tures that depend on complex relationships among bones, ligaments, and muscles. Plain-film x-ray examination does not evaluate move- ment of the spine, nor does it directly assess the soft tissues.
Although the limitations of radiographic marking systems are well established469 (Box 3-14), static alignment abnormalities can
have some significance when taken in context with other clinical, historical, and laboratory findings. In recent years, more empha- sis has been placed on the dynamic concepts of the subluxation
BOX 3-13
Five-Point grading System forMuscle Weakness
5—Patient can maintain position against gravity and maximum examiner-applied resistance.
4—Patient can maintain position against gravity and minimal examiner-applied resistance.
3—Patient can maintain position against gravity.
2—Patient can move through arc of motion when gravity is lessened.
1—Muscle contraction is visible or palpable, but there is no movement of part.
Figure 3-31 Static spinographic measures. A, Anteroposterior open mouth. B, Anteroposterior lower cervical. C, Anteroposterior thoracic and D, anteroposterior lumbar and pelvis. E, Lateral cervical neutral. F, Lateral thoracic and g, lateral lumbosacral.
A
L
B C
D E F
complex, in some cases totally disregarding static biomechanical relationships. Sandoz470 feels that this shift of emphasis is coun-
terproductive. He suggests considering the mechanical, static, and dynamic concepts in harmony with the neurologic and reflex elements of spinal subluxation/dysfunction.
Over the years, the role of x-ray examination has been modi- fied according to scientific and technical developments, as well as to philosophic tenets and beliefs. Sherman462 summarized the clin-
ical rationale for the use of x-ray examination in chiropractic (Box 3-15). Evidence-based diagnostic imaging practice guidelines have been developed.471-474 They are intended to assist primary care pro-
viders, interns, and residents in determining the appropriate use of diagnostic imaging for specific clinical presentations. In all cases, the guidelines are intended to be used in conjunction with sound clinical judgment and experience. The goal of these guidelines is to avoid unnecessary radiographs, increase examination precision, and decrease health care cost without compromising the quality of care.471 Ammendolia and co workers475 surveyed chiropractic
colleges around the world to evaluate whether imaging guidelines were being taught and adhered to. The results of this study sug- gest that instruction provided at most chiropractic schools appears to adhere to evidence-based guidelines for LBP with respect to the use of routine radiography, full-spine radiography, and oblique views, but there appears to be some disparity between instruction and existing evidence for the use of radiography in acute LBP.475 Spinal X-ray Examinations
Historically, the use of spinal radiography examinations in chiro- practic centered on the detection and quantification of the inter- vertebral misalignment.476 Proponents of radiographic evaluation
for the detection of spinal subluxations claim that x-ray examina- tions are the best method for accurately determining the level and direction of vertebral malposition.460 They contend that chiroprac-
tors who do not use radiography to evaluate spinal subluxations
are at a disadvantage in determining and delivering indicated and safe adjustments. In the 1970s, this view produced a policy requiring chiropractors to demonstrate radiographically the pres- ence of spinal subluxations to treat and receive reimbursement for Medicare patients. This policy has been recently modified and was rescinded in 2000 in favor of the PART multidimensional index for joint dysfunction.
Preadjustive x-ray examinations are also rationalized as necessary because the treatment incorporates the use of force. It is reasoned that the integrity and mechanical characteristics of the spine should first be screened radiographically before adjustments are made.476
This position is controversial and unsubstantiated. Screening x-ray examinations taken without clear clinical guidelines have not correlated with improved diagnosis or patient outcome.477,478
Furthermore, thrusting forms of manipulation have been used safely for centuries without the aid of x-ray examinations.
Spinal x-ray examinations are usually taken with the patient in an upright, weight-bearing position and should consist of two views, typically an anteroposterior and lateral projection. Traditionally, the alignment of the upper vertebrae is compared with that of the lower vertebrae, and any malpositions are recorded.32,128,460
Full-spine radiographs are used primarily for biomechanical evaluation, including the assessment of individual motion seg- ment alignment. Full-spine evaluations provide an integrated view of spinal biomechanics and are the method of choice in the evalu- ation of spinal scoliosis. Full-spine radiographs, however, compro- mise bony detail and should not be used as a routine procedure for the assessment of suspected local pathologic conditions.469,479,480
“The clinical justification for the full-spine radiograph must insure that the benefit to the patient is greater than the radia- tion hazard. The film must be of such quality that the presence or absence of pathology can be determined.”481 When indicated,
consideration should be given to full-spine posteroanterior pro- jections to improve visualization of the lumbar IVD spaces and to minimize exposure to the ovaries and breasts.31,461
Although the majority of the profession uses some form of radiographic measurement and assessment of spinal subluxation, there is considerable controversy as to whether radiographic eval- uation should play a significant role in the diagnosis of spinal subluxation syndromes.* Claims of accuracy in detecting minor joint malpositions may not be supportable against the technical limitations of radiography.† Inherent radiographic magnification
and distortion, patient positional errors, and the exactness of the marking procedures are common concerns.
The lack of a consensus on the definition, pathophysiology, and pathomechanics of spinal subluxations further complicates the debate and analysis of x-ray marking procedures. Therefore, the clinical significance of these measurements is controversial and suspect. Radiographic measures should not be the primary criteria used to perform chiropractic care.489 However, if there were a clin-
ical indication for taking a radiograph, it would be imprudent not to evaluate the x-ray examinations for biomechanical relationships and look for correlations to other clinical findings.
BOX 3-14
Limitations of Radiographic Marking SystemsAnatomic asymmetry Radiographic magnification Radiographic distortion Radiographic malpositioning
Static analysis of dynamic motion segments Inaccuracy of instruments
Insignificant findings
BOX 3-15
Rationale for Radiography in Chiropractic Practice to Establish a Clinical DiagnosisTo evaluate biomechanics and posture To identify anomalies
To screen for contraindications To monitor degenerative processes
†References 335, 461, 463, 479, 481, 484-488.
The process of critically evaluating radiographic marking pro- cedures has only begun in the last several decades.335,478,490-495 The
process is in its infancy, and a limited number of studies have been conducted. A significant number of procedures have yet to be evaluated. Although it is difficult to draw firm conclusions, it is possible to briefly summarize the present state of affairs.
First, many of the radiographic marking procedures used to evaluate segmental spinal alignment can be reliably performed.*
However, most of the reliability studies do not include a full eval- uation of all the steps involved in performing and determining segmental alignment. Many of the studies did not include patient positioning. Consequently, at this time it is difficult to conclude whether x-ray marking procedures are or are not reliable for iden- tifying spinal motion segment subluxations.469
Although recent attempts have been made to address issues of spinographic reliability, very little has been done to investigate the validity of radiographic measurement in diagnosing and treating spinal dysfunction.338,470,476-478,496,497
Spinal displacement analysis has not demonstrated the ability to identify an established clinical entity nor demonstrated its value as an independent outcome measure. The validity and clinical usefulness of static marking procedures for identifying treatable motion segment misalignment have not been demonstrated.488
A retrospective case analysis performed in 1990 identified only one postmanipulation segmental spinographic change, that being a reduction in retrolisthesis. There was no identified change in cervical lordosis, sacral base angle, lumbar lordosis, scapular angle, or Cobb angle.489 Yi-Kai and coworkers504 investigated the rela-
tionship between radiographic signs of subluxation in the cervi- cal spine and their clinical diagnostic value. They concluded that there was little evidence to support the contention that signs of subluxation in the cervical vertebrae are diagnostically significant in identifying individuals with cervical pain. In addition, static marking procedures have not been found to discriminate between those with back pain and those without back pain.338,505
Harrison et al483 reviewed the literature on the reliability and
clinical value of spinal displacement analysis in plain-film x-ray examinations, concluding that x-ray line drawing is a reliable and effective outcome measure. The conclusion is based on their assertion that there is an ideal normal spinal configuration based on a mathematical model and that radiographic marking proce- dures can identify real spinal displacements. However, the vast majority of cited reliability studies were on curve measurements, not spinal segment position.
Haas and colleagues469 challenged Harrison and colleagues
conclusions483 by questioning the biologic plausibility of an ideal
spine model and the authors’ failure “to present any credible evi- dence for the validity, clinical utility and appropriateness for using these procedures.” Haas and colleagues469 conclude that there is
currently no justification for the routine use of radiographic spinal displacement analysis in clinical practice.
Functional X-ray Examination
The potential limitations of static radiographs in determin- ing joint dysfunction has led to increased use of functional x-ray
studies.51,506-510 The principal attraction of functional x-ray exami-
nations is the ability to assess joint mobility and identify distur- bances in function that might not be represented by static films. Functional x-ray studies involve the evaluation of regional and seg- mental spinal movements by comparing range and pattern of move- ment at each segmental level. A series of three views are typically taken for each plane of movement evaluated: an end-range view in each direction and a neutral view. These views are then used to measure and evaluate restricted or aberrant segmental movements.
Although the use of dynamic x-ray examinations overcomes concerns about the inability to functionally assess the spine with static x-ray examinations, there remains considerable controversy as to their contribution in predicting back pain or differentiating those individuals with back pain from those without. Methods for measuring and classifying segmental motion abnormalities in the lumbar spine and cervical spine are in common use.51,164,506–508,511–513
Taylor478 suggests that functional radiography should be used to
establish the presence of the following: 1. Segmental or global hypomobility 2. Segmental or global hypermobility 3. Segmental instability
4. Aberrant segmental or global motion 5. Paradoxical motion
6. Postsurgical arthrodesis
Flexion-Extension Radiographs. Those investigating the rela- tionship between spinal pathologic conditions and segmental movement have demonstrated supportive evidence for the use of flexion-extension studies in the detection of spinal instabil- ity.167,478,506,514 Flexion-extension studies are used to identify exces-
sive angular or translational movements between spinal segments (Figure 3-32).478,515,516 The amount of translation or angular move-
ment necessary to define instability is not definitively established. Most references classify any flexion-to-extension translation greater than 3 to 5 mm as indicative of instability.478 Dvorak and
colleagues517 suggest that applying global overpressure at the end
ROM during a functional x-ray examination may aid in identify- ing translational movement characteristics of instability.
Clinical validity studies have been done for flexion-extension radiographs of the lumbar and cervical spine.518,519 The conclu-
sions were that the functional studies did show a tendency for the presence of hypomobility in patients with clinical problems, but they were not sufficient to aid in differentiating the underlying pathologic conditions.
In the cervical spine, flexion-extension studies are used most commonly to ascertain if a traumatic injury has resulted in
*References 265, 335, 464, 470, 476-478, 483-486, 490, 494-503
Figure 3-32 Evaluation of flexion and extension radiographs in the cervical and lumbar spine.
instability. Translational movements of more than 3 mm are con- sidered a significant finding for instability of the cervical spine. In the cervical spine, an overlay method may be used for templating flexion and extension (see Figure 3-32).
Lateral-Flexion Radiographs. Lateral-flexion (side-bending) radiographs are used predominantly in the evaluation of the lum- bar spine. Interpretation of the films incorporates the use of lines and angles that are drawn on the films for the purpose of quantify- ing and gauging comparative quality of joint motion.
The total range of regional lateral flexion is determined by extending a line from the superior end plate of the uppermost vertebra and the inferior end plate (or sacral base) of the lowest vertebra in the concavity of the curve. Perpendicular lines are con- structed from each of these with the angle formed at their intersec- tion, establishing the limit of lateral flexion (Figure 3-33).
The films can then be marked for segmental rotation and lat- eral flexion. The body-lamina junction is used for rotation and the end plate angulation for lateral disc wedging. Aberrant lat- eral flexion can be assessed by using superior end plate lines and evaluating if they converge toward the side of lateral bending (see Figure 3-33).
Early investigation into the value of functional radiography did identify its merit in the diagnosis of sciatica,520 although abnor-
mal lumbar motion was also noted in asymptomatic patients. Vernon509 concluded that there was a higher prevalence of abnor-
mal lateral bending patterns in symptomatic subjects, but Phillips et al329 and Haas and colleagues332,333 failed to demonstrate a rela-
tionship between abnormal spinal motion and patients suffering from LBP.
Although these procedures have demonstrated limited predic- tive value in differentiating individuals with back pain from those without, their value in managing patients with back pain has not been fully assessed. Using side-bending stress x-ray studies to help ascertain abnormalities of intersegmental motion in individuals with back pain in theory, may affect clinical decision-making in a manner that improves patient outcome. In this context, evalua- tion would be qualitative and quantitative. The detection of hypo- mobility, paradoxical motion (reversal of an unexpected motion or aberrant motion), or excessive motion would have precedence over exact measurements.
Identifying levels and directions of decreased movement might affect decisions on where and how to make adjustments in ways that improve patient outcome. This may be particularly applicable in individuals with persistent pain or patients who have not been responsive to treatment. The answers to these questions await further research.
Videofluoroscopy
Videofluoroscopy (VF) of the spine is another radiographic procedure that has been proposed as a potential tool for the assessment of segmental spinal motion. Before the develop- ment of VF, cineradiography (CR) was the main radiographic method used to evaluate spinal motion. Fielding521 first
described its use for the cervical spine, and Illi was the first to use CR in the chiropractic profession to study spinal seg- mental and sectional motion. He was followed by Rich and Goodrich in the 1960s. Howe57,522 performed numerous stud-
ies, and this procedure became an experimental procedure at a number of institutions. The major drawback to CR was that it involved taking 16-mm movies during which substantial radi- ation exposure (often exceeding 10 or 20 radiation absorbed doses) was applied to the spine.
VF development has led to improvements in image intensifi- ers and digital recording technology that has resulted in far fewer radiation doses and increased interest in recent years.523,524 VF
has the capabilities to measure the full arc of motion and there- fore provides information on the quality of motion in addition to the ROM. This allows the clinician to see aberrations in the mid-ROM, as well as at the extremes. Advocates of VF suggest that these studies provide objective evidence of biomechanical abnormalities not seen with other studies. This technology has made significant advances, and the new techniques of digital VF A
B
C
E
D
Figure 3-33 Evaluation of functional lateral bending radiographs in the lumbar spine demonstrating movement patterns. A, Type I, lateral bending with contralateral rotation. B, Type II, lateral bending with ipsilateral rotation. C, Type III, contralateral bending with contralat- eral rotation. D, Type IV, contralateral bending with ipsilateral rota- tion. E, Segmental measurement methods for determining rotation in millimeters and lateral flexion in degrees. (A–D from Grice A, Cassidy D: J Manipulative Physiol Ther 2:18, 1979; E from Haas M, Nyiendo J, Peterson C: J Manipulative Physiol Ther 13[4]:179, 1990.)
(DVF) have dropped the radiation exposure rates considerably below those of the conventional x-ray examination.525,526 When
appropriate equipment and calibration are used, the procedure has demonstrated promising interobserver and intraobserver reliabil- ity, with measurement accuracy between 1 and 2 degrees.525-527
Although DVF holds significant promise in the assessment of spinal mechanics, it is presently in the investigational stage, with- out established clinical protocols for use. It should be stressed that spinal VF is a special test with several limitations and disadvan- tages (Box 3-16). Much research is necessary to precisely define the role of VF in chiropractic.
In clinical practice, VF should be considered an experimental procedure, and its use should be reserved for complex cases that fail to respond, that respond poorly to a trial of conservative man- agement, or in which suspected ligamentous damage leading to instability has occurred. Growing concern about the inappropriate use of VF has led to the formation of protocols for the use of VF in chiropractic by the American Chiropractic College of Radiology, a branch of the ACA. These protocols should be followed when contemplating the use of VF.528
Clinical Use of X-ray Examination
The clinical utility of static and functional radiographs might be improved if these procedures were placed in a proper clinical perspective and considered a component of evaluation and not a pathognomonic indicator of JSDSs. With further refinement, they may eventually parallel a role provided by specialized imaging techniques in the structural detection of IVD derangement.
For example, the presence of IVD derangement on a CT scan or an MRI indicates the presence of anatomic derangement of the IVD, but it does not confirm that the disc derangement is of clinical significance. The incidence of radiographically detected disc derangement in asymptomatic patients is significant (24% to