Functional Evaluation of the Lumbar Spine with Axial Loaded Computed Tomography (AL-CT) and Cine AL-CT

Abstract

Italian

This study reports a personal experience in the functional study of the lumbar spine with original diagnostic techniques called Axial Loaded Computed Tomography (AL-CT) and Cine AL-CT, based on the use of the Axial Loader, a device that develops a variable and reproducible axial load in a supine patient during computed tomography or magnetic resonance investigation^3,4.

We built a non ferromagnetic, X-ray transparent bed (the Axial Loader), with double blocking rests for shoulders and feet, that can be used during CT and MR spine studies. The inferior block is a platform that moves continuously in a longitudinal direction, with a micrometric mechanism. A dynamometer placed between the inferior platform and the patient's feet can measure the load applied.

We studied 75 patients, with a clinical and diagnostic suspicion of lumbar spine instability. The examinations were performed on a conventional CT unit (GE Sytec 3000, General Electric, Milwaukee) with a “volumetric” approach to the lumbar spine.

In conclusion, AL-CT and Cine AL-CT is currently the only diagnostic modality that can give dynamic information on the differents UFSs in all their components in one mildy invasive, easily reproducible diagnostic examination.

Keywords

lumbar spine functional study CT

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References

Brickmann

: Injury of the annulus fibrosus and disc protrusion: An in vitro investigation on human lumbar disc. Spine 11: 149–153, 1986.

Burgener

Kormano

: Differential diagnosis in conventional radiology. Georg Thieme Verlag, Stuttgart, 1987.

Cartolari

Boni

: La tomografia computerizzata con carico assiale della colonna lombare. Osservazioni preliminari. In: Salvolini

Leonardi

(eds): Neuroradiologia 1993. Edizioni del Centauro, Udine 1993: 95–100.

Cartolari

Scarfò

: La TC con carico assiale nella instabilità del rachide lombo-sacrale. Rivista di Neuroradiologia 9: 147–155, 1996.

Depuis

Yung-Hing

: Radiologic diagnosis of degenerative lumbar spine instability. Spine 10: 262–276, 1985.

Dyson

GHG

: The mechanism of athletics. Press Ltd, University of London; London 1968.

Graf

: Instabilité vertébrale lombaire: Diagnostic, nouvelle tecnique de traitment par stabilisation souple. La Revue de Médecine Orthopédique 28: 15–19, 1992.

Ito

Tadano

: A biomechanical definition of spinal segmental instability taking personal and disc level differencies into account. Spine 15: 2295–2304, 1993.

Krag

Seroussi

: Internal displacement distribution from in vitro loading od human thoracic and lumbar spine motion segments: Experimental results and theoretical predictions. Spine 12: 1001–1007, 1987.

10.

Kramer

: Intervertebral disc desease. Georg Thieme — Verlag, Stuttgart — New York 1990.

11.

Kaech

: Lumbar disc herniation, spinal stenosis and segmental instability: Role of diagnostic imaging. Rivista di Neuroradiologia 8 (Suppl 1): 99–109, 1995.

12.

Knutsson

: The instability associated with disk degeneration in the lumbar spine. Acta Radiol 25: 593–609, 1944.

13.

Lin

: Mechanical response of lumbar intervertebral joint under phisiological (complex) loading. J Bone Joint Surg 60: 41–55, 1978.

14.

Nachemson

: Lumbar intradiscal pressure: Experimental studies on post-mortem material. Acta Orthop Scand Suppl 43: 1–104, 1960.

15.

Nachemson

Elfstrom

: Intravital dynamic pressure measurements in lumbar discs. A study of common movements, maneuvers and exercises. Scan J Rehab Med 1: 1–40; 1970.

16.

Nachemson

Schultz

: Mechanical properties of human lumbar spine motion segments: Influence of age, sex, disc level and generation. Spine 4: 1–8, 1979.

17.

Nowiki

Shiwei

: Effect of axial loading on neural foramina and nerve roots in the lumbar spine. Radiology 176: 433–437, 1990.

18.

Olsson

Selvik

: Mobility in the lumbosacral spine after fusion with the aid of Roengen stereophotogrammetry. Clin Orthop 129: 181–190, 1977.

19.

Panjabi

Krag

: A technique for measurement and description of three dimensional six degree of freedom of a body joint with an application to the human spine. J Biomech 14: 447–460, 1981.

20.

Smith

: In vitro spinal biomechanics. Experimental methods and apparatus. Spine 10: 1204–1210, 1991.

21.

Smith

Fernie

: Functional biomechanics of the spine. Spine 10: 1197–1203, 1991.

22.

Stockes

Wilder

: Assessment of patients with low back pain by biplanar radiographic measurement of intervertebral motion. 1980 Volvo award for spine research. Spine 6: 233–240, 1981.

23.

Wood

Popp

: Radiographic evaluation of instability in spondylolisthesis. Spine 19 (15): 3–10, 1994.

24.

Yang

King

: Mechanism of facet load transmission as an hypothesis of low back pain. Spine 9: 557–565; 1984.