FUNCTIONAL SCANOGRAM IN THE DIAGNOSIS OF POST-TRAUMATIC FIXED SAGITTAL IMBALANCE.

Abstract

Introduction: Flat Back Syndrome resulting from decreased lumbar lordosis or increased thoracolumbar kyphosis was initially described by Doherty¹ in post scoliotic surgery patients. This decompensation was later coined as fixed sagittal imbalance and was also detected in patients operated for ankylosing spondylitis or with fractured vertebrae. Various clinical symptoms were included in the syndrome such as stooped posture, knee/ hip flexion compensation, fatigue of para-spinal muscles, neck pain and upper spinal deformities, imbalanced gait. Surgical corrections were described by Kostuik², Lagrone³, Farcy⁴ and others. The “normal” assessments were varying, but accepted according to Propst-Proctor⁵ and Bernhardt & Bidwell Segmental measurements⁶. The clinical diagnosis was supported by radiological evaluation using the Cobb technique and a plumbline alignment from odontoid to promontorium. This evaluation required multiple sets of x-ray films.

Methods: Our preliminary study is aiming at describing in detail the clinical syndrome in patients with lower dorsal and upper lumbar vertebral compressions. Scanogram CT- imaging of the spine is suggested for diagnosis, a rapid technique reported to be with at least 40% reduced radiation^7,8. The scanogram is suggested to be functional as it is repeated in prone and in supine positions. The two films were superimposed and rigidity assessed, angles were measured (Cobb) at the T/L junction (two above and two levels below the fracture) and of the lumbar lordosis (from Inferior L1 to superior L5).

Results: This technique was applied to eight patients: the clinical syndrome is detailed with one additional, as yet unreported feature, namely the sleeping position. These were patients with two, three or four vertebral compressions, resulting in imbalance of the dorsolumbar junction and deformity of the lumbar lordosis. All patients had increased T/L kyphosis of varying degrees, all but one had parallel loss of lordotic curvature.

Discussion: A different imaging technique, functional and less irradiating is suggested for the diagnosis of fixed sagittal imbalance of the dorsolumbar spine and is applied to deformities resulting from fractured vertebrae. The clinical syndrome is enlarged with one feature, namely sleeping in prone position. These early impressions need a larger prospective study for confirmation.