"Subluxations and Dislocations
Definition. A subluxation may be defined as a partial dislocation. It is any pathological situation in which there is not a normal physiological juxtaposition of the articular surfaces of a joint. Such situations should be reliably demonstrable radiographically."I agree, and yes subluxations should be "reliably demonstrable radiographically," and to do so they are at best analyzed and their malposition reduced to numbers. In his article, Dr. Innes illustrates a classic disc block subluxation taken from Kapandji; this subluxation can be readily analyzed radiographically using chiropractic line analysis and rotational analysis systems.
H.B. Logan's method of dotting the junction of lamina and the inferior tips of the vertebral bodies has been used in this profession since the 1930s to determine vertebral rotation. Spinous process deviation is recognized as causing distraction of the facet on the side opposite the spinous deviation. In the paper, "Spinous Process Deviation,"2 Ravichandran quotes Farfan's observation that spinous process deviation, "... was associated with apophyseal injuries, leading to compression of the articular facet on the side of deviation with distraction of the contralateral facet." Ravichandran also used line analysis to determine the spinous process deviation. Chiropractic radiographic rotational analysis goes a step further: it reduces the rotational deviation to numbers. I personally modified H.B. Logan's method by using the centers of the lateral concavities of the vertebral body margins rather than the inferior body margins as the inferior tips of the vertebral bodies are often distorted with pathology. The Bunnel3 method has verified the efficacy of this procedure by using the same reference points. When compared to three other methods of film marking to determine vertebral rotation, it was found to be the preferred method as it "... gives a good estimation of the rotational deformity present, and involves minimal exposure of the patient to radiation."3
In regards to disc wedge, Sir Sydney Sunderland4 states:
"Narrowing of the lumbar intervertebral distance, whatever the cause, results in the subluxation of the apophyseal joints in which the facet of the vertebra above is displaced inferiorly across the surface of the facet of the vertebra below."
Fenneson also observes this factor and refers to it as overriding:5
"... facet dysfunction may occur from derangement and instability of the facet joint, resulting from overriding secondary to a collapsed degenerated intervertebral disc."Yes, when a disc collapses to one side the facet of the superior vertebra overrides its articular mate on the inferior side of the disc wedge. The disc wedge subluxation is widely recognized both medically and chiropractically and it can be easily analyzed through the simplistic disc wedge line analysis of the late Clarence Gonstead, DC. The disc wedge lines and the measurement of the angulation can also quantify the disc wedge element of the subluxation. Weitz6 proved that this subluxation was reliably demonstrable radiographically even when the patient was subjected to lateral bend and flexion extension radiographs. The study showed that the subluxation remained the same, a true articular lock.
Atlas, axis, and occipital subluxations have been located radiographically with line analysis methods by chiropractors for over eight decades. The work of Palmer, Grostic, Kale, Sweat, Harrison, Pettibon, Blair, and NUCCA practitioners have all been vindicated by research projects developed by Dr. John Grostic and published by the Life Chiropractic College in Marietta, Georgia. Medicine, even as far back as 1977, has analyzed the atlas/axis subluxation through line drawings. For instance, the Journal of the AMA reported on the analysis of vertical subluxation of the odontoid and horizontal subluxation of the atlas in rheumatoid arthritis:
"Horizontal subluxation: Distance from anterior surface of odontoid to posterior surface of C-1 arch exceeds 2.5 mm. Vertical subluxation: tip of odontoid extends more than 4.5 mm above McGregor's line, line drawn from posterior margin of hard palate to most caudal part of occiput."7And what about Ullman's line, George's line, and Barge's anterior guideline for retrolisthesis and vertebral instability. Egads, Dr. Innes, I'm sure that most of us are aware that components of motion will identify and change certain elements of so called fixations, thus altering our static evaluation on x-ray. We are also aware that patient positioning and altering postural alignment creates variances in imaging, but to demean line drawing analysis as basically worthless is uncalled for. This is your opinion, doctor, and it most certainly runs counter to mine. Elements of motion can can help determine corrective adjustic line of drive and augment the full appreciation of the intricacies of the VSC, but they do not negate the value of line drawing analysis.
- White, Panjabi. Clinical Biomechanics of the Spine, 1978, p. 504 (p. 683 in latest edition).
- Ravichandran (quotes Rarfan). Spinous process deviation. Spine 8(3), 1983.
- Russell, Roso, McIvor. A comparison of four computerized methods for measuring vertebral rotation, Spine 15(1), 1990.
- Sunderland S. Nerve and Nerve Injuries, p. 1,029, Churchill Livingstone, 1978.
- Fenneson B. Low Back Pain, p. 563, Lippincott.
- Meitz E. The lateral bending sign, Spine (6)4, July/Aug., 1981.
- Davidson, Horn, Herndon, Grin. Brain stem compression in rheumatoid arthritis, JAMA, Dec. 12, 1977, (238)24.
Fred Barge, DC, PhC
La Crosse, Wisconsin