ANALYSIS OF LUMBOSACRAL LORDOSIS USING STANDING LATERAL RADIOGRAPHS THROUGH CURVE RECONSTRUCTION

The consensus of the normal magnitude of lumbosacral curve has not been achieved. The Cobb's angle cannot depict the whole contour of this curve. For practical applications, a clearer image of these curves and their aging changes should be further investigated. This study aimed to provide a more consolidate concept of normal lumbosacral curves for clinician through a computerized reconstruction method. Standing lateral radiographs of lumbosacral spine in 82 normal adults were used for reconstructing the sagittal lumbosacral curves. The geometric characteristics of these curves according to the gender and age groups were studied. Using standing lateral radiographs, reconstruction of the lumbosacral curves was performed through digitization, programming and computation. These curves and related parameters were normalized and averaged for analyzing the differences of gender and age. The most anteriorward and horizontal vertebrae usually occurred on the L4 and L3 in any gender and age groups. The sacral inclination angle did not change obviously with the increasing ages. A tendency of L1 shifting backward was noted in the age groups of 40 to 60 and above 60 years old. The sagittal lumbosacral curves can be easily reconstructed by digitizing lateral radiographs, The aging changes of lumbosacral curves could be qualitatively described as the flattening of lower lumbar curve and the rearward inclination of upper lumbar curve. The changes occurred obviously above 40 years old. Although individual variations existed, the aging changes and the geometric characteristics such as the most anteriorward or horizontal vertebrae could be used as an important guideline during therapy or surgical correction.

Prognostic Radiographic Aspects of Spondylolisthesis

A series of 202 patients (133 men, 69 women) with lumbar spondylolysis were examined radiographically on two occasions, first at the time of diagnosis and later at a follow-up, after an observation period of 20 years or more. The films from patients in groups without and with moderate and severe olisthesis were evaluated with respect to variables describing lumbosacral lordosis, wedging of the spondylolytic vertebra, lengths of the transverse processes and iliolumbar ligaments, disk height, progression of slipping, and influence on measured olisthesis of lumbar spine flexion and extension at the radiographic examination. The evaluation was made with special attention to possible signs which could be predictive for the prognosis of vertebral slipping. Progession of slipping did not differ between patients diagnosed as adults or adolescents. Reduction of disk height was correlated to the degree of slipping present at the initial examination and to the progression of olisthesis. Flexion and extension of the lumbar spine did not modify the degree of olisthesis. Data concerning the lengths of the transverse processes and the iliolumbar ligaments, and lumbar lordosis, cannot be used for prognostic purposes. The lumbar index reflecting the degree of wedge deformity of the spondylolytic vertebra was shown to be the only variable of prognostic value for the development of vertebral slipping.

Radiographic Assessment of Anatomic Deviatoins in Lumbar Spondylolysis

A series of 202 patients (133 men, 69 women) with spondylolysis were examined with respect to radiographic variables describing lumbosacral lordosis, size of lumbar vertebrae, transverse processes and disc height. An age-standardized and sex-stratified comparison was made with a control group of 170 subjects (68 men, 102 women) without lumbar spine disorders. The difference in ***lumbosacral lordosis between the spondylolysis and control groups was considered to be secondary to olisthesis, and to lack an etiologic role for the genesis of lysis. The lengths of the transverse processes and their distances to the crista iliaca posterior demonstrated no differences between the groups and therefore did not seem relevant to the context of the pathogenesis of spondylolysis. The fifth lumbar vertebra in the spondylolytic patients was more wedged and less wide than in the controls. The question of the primary or secondary nature of this change has not yet been clearly elucidated, and should be given further attention. The spondylolytic patients demonstrated a decrease in the height of the L5-S1 disc much earlier than the controls, and the degree of narrowing of the disc space was much more marked.