Total Lumbar Lordosis Research Articles

The Relationship between Sagittal Spinal Alignment and Surgical Results in Degenerative Lumbar Scoliosis with Spinal Stenosis

Study Design : A retrospective study. Objectives : To analyze the correlation between clinical results and sagittal vertical axis, clinical results and total lumbar lordosis in degenerative lumbar scoliosis with spinal stenosis. Summary of Literature Review : There has been no report about the relation between sagittal spinal alignment and surgical outcome of degenerative lumbar scoliosis. Materials and Methods : We reviewed 38 surgical cases of degenerative lumbar scoliosis from February 1997 to February 2001 with an average follow-up of 35 months. In whole spine standing AP and lateral radiographs, scoliotic angle(Cobb method), total lumbar lordosis(L1∼S1) and the sagittal vertical axis(C7 plumb line) were measured. In lumbar flexion-extension and standing side bending views, the lateral translation was measured and instability was determined. Clinical results were evaluated based on the Kirkaldy-Willis criteria. Results : The scoliotic angles at preoperative, postoperative and follow-up were 15.0±4.9, 5.3±3.1 and 7.1±3.7 degrees retrospectively. Total lumbar lordosis were 28.7±6.1, 40.6±7.3 and 35.1±10.2 degrees retrospectively. Sagittal vertical axis at preoperative and the last follow-up were 3.3±3.2 and 0.1±3.3 cm retrospectively. According to Kirkaldy-Willis criteria, 6 cases were excellent, 24 cases good, 7 cases fair and 1 case poor. There was no statistical correlation between total lumbar lordosis and the clinical results (r=-0.061, p=0.717). Sagittal vertical axis was significantly correlated with the clinical results (r=0.519, p=0.001). Conclusions : For improvement of surgical outcome of degenerative lumbar scoliosis, the sagittal vertical axis should be used as a parameter of sagittal alignment rather than the total lumbar lordosis.

Segmental Roentgenographic Analysis of Vertebral Inclination on Sagittal Plane in Asymptomatic versus Chronic Low Back Pain Patients

Two homogenous groups of 120 volunteers and 120 low back pain (LBP) patients, age range 20-79 years, underwent a prospective roentgenographic segmental vertebral analysis of the thoracic and lumbar spine to compare several roentgenographic parameters useful for planning spine surgery. The following roentgenographic parameters were measured: thoracic kyphosis, lumbar lordosis, sacral inclination, distal lordosis (L4-S1), inclination of each vertebra from T4-S1, and relative vertebral inclination between adjacent vertebrae. Thoracic kyphosis increased (p < 0.0001) and sacral inclination decreased (p < 0.05) with age in the control group. Increased thoracic kyphosis correlated with decreased lumbar lordosis after the sixth decade in the control group (p < 0.01), less so in the LBP group (p < 0.05). Increased thoracic kyphosis was seen more in the LBP group than in the controls, but significantly solely in the sixth decade (p < 0.01). Lumbar lordosis was more increased in the controls than in the LBP group but significantly solely in the sixth decade (p < 0.001). The L5-S1 segmental lordosis was much more in the LBP patients than in the controls (p < 0.001). Lumbar lordosis was strongly correlated with sacral inclination in both groups (p < 0.0001) and it was significantly greater in the controls, particularly in the sixth decade (p < 0.001). Sacral inclination was significantly more in the female than in male volunteers (p < 0.05). Distal lordosis (L4-S1) represents 55% and 49% of total lumbar lordosis in controls and low back patients, respectively. Spine surgeons frequently deal with sagittal spinal deformities and the deviations of sagittal spinal curvatures and vertebral inclination in the sagittal plane, both in normal subjects and LBP patients should be clinically helpful.

A Comparison between Anterior Threaded Cages vs. Posterior Pedicle Screw Instrumentation in Terms of Foraminal Distraction and Lumbar Lordosis

A cadaveric study was performed to compare the effect of anterior versus posterior distraction instrumentation on lumbar foraminal height and lordosis. Pedicle screws and interbody instrumentation can be used to distract vertebral bodies, thereby increasing foraminal height. BAK interbody cages were inserted anteriorly at L4-L5 and L5-S1 in ten spines. Isola instrumentation was applied posteriorly in six spines at L4, L5, and S1. Both anterior instrumentation and posterior pedicle screw instrumentation provided significant increase in foraminal height with slight decrease in total lumbar lordosis. Foraminal height increased with larger cages at the level in which the cages were first applied, and the addition of cages at the neighboring level had a little effect. However, no statistically significant differences were found with different sizes of cages at the neighboring level. The maximum change in foraminal height occurred with 10 mm of posterior distraction, but a plateau effect was observed over six mm. Distraction of the lumbar spine is effective in increasing foraminal height with relatively small losses of lumbar lordosis. Similar increases were obtained with the anterior and posterior approaches. The surgeon should choose a particular method based on the patient's pathology.

The lordotic effect of the OSI frame on operative adolescent idiopathic scoliosis patients.

A prospective evaluation of adolescent idiopathic scoliosis patients undergoing operative treatment on the Orthopedic Systems Incorporated (OSI; Jackson) frame. To investigate prospectively thoracic, thoracolumbar, and lumbar sagittal alignments in patients with adolescent idiopathic scoliosis who undergo an instrumented posterior spinal fusion on the OSI frame. In several studies, it has been shown that patient positioning on various operative frames is an important component of ultimate lumbar sagittal alignment. However, these studies have all concentrated on the lumbar spine, and no sagittal plane alignment data in adolescent idiopathic scoliosis patients have been reported in the thoracic and thoracolumbar junction as it relates to intraoperative positioning, correction maneuvers and correlative postoperative results. Thirty-nine patients with operative adolescent idiopathic scoliosis treated with an instrumented posterior spinal fusion on the OSI frame were prospectively evaluated. Standing preoperative, intraoperative, and postoperative long-cassette lateral radiographs were reviewed with regional and segmental Cobb measurements of the thoracic, thoracolumbar junction, and lumbar spine obtained. Thoracic kyphosis (T1-T12) measured +34 degrees before surgery, +28 degrees during surgery, and +30 degrees after surgery, Thus, a statistically significant decrease was noted in thoracic kyphosis secondary to prone positioning on the OSI frame ( P < 0.05). Thoracolumbar spine measurements from T10 to L2 also showed a lordotic trend from +2 degrees before surgery, to -4 degrees during surgery, to -8 degrees after surgery, which was also statistically significant (P < 0.05). Total lumbar lordosis from T12 to S1 remained relatively unchanged from -60 degrees before surgery, to -59 degrees during surgery, to -60 degrees after surgery. However, segmental lumbar lordosis measured from T12 to the lowest instrumented vertebra showed a statistically significant increase in lordosis from -17 degrees before surgery, to -19 degrees during surgery, to -23 degrees after surgery (P < 0.05). Those patients in whom lumbar pedicle screws were used (vs. hooks alone) had the greatest increase in lumbar instrumented lordosis. Performing adolescent idiopathic scoliosis correction on the OSI frame tends to decrease thoracic kyphosis, increase thoracolumbar lordosis, and increase segmental instrumented lumbar lordosis, while it maintains total lumbar lordosis.

Reciprocal angulation of vertebral bodies in the sagittal plane in an asymptomatic Greek population.

A prospective study conducted on several roentgenographic parameters of the standing sagittal profile of the spine in an asymptomatic Greek population. To perform segmental analysis of the sagittal plane alignment of the normal thoracic, lumbar, and lumbosacral spines and to compare the findings with those derived from similar populations. Until recently, little attention has been paid to the sagittal segmental alignment of the spine, and there are only a few studies (in French and American populations) in which radiographic analysis of sagittal spinal alignment is investigated. Ninety-nine consecutive asymptomatic Greek volunteers (38 men, 61 women), an average age of 52.7 +/- 15 years old (range, 20-79 years), were included in this prospective study, on the basis of several inclusion criteria. These volunteers were divided into six distinct age groups. The radiologic parameters, which were measured (by Cobb's method) on the lateral standing roentgenograms of the whole spine were: thoracic kyphosis (T4-T12), lumbar lordosis (L1-L5), total lumbar lordosis (T12-S1), distal lumbar lordosis (L4-S1), sacral inclination (measured from the line drawn parallel along the back of the proximal sacrum and the vertical line), pelvic tilting, vertebral body inclination, and relative segmental inclination between pairs of adjacent vertebrae. Thoracic kyphosis and lumbar lordosis (T12-S1, L1-L5) were not gender related. Thoracic kyphosis increased with age (P < 0.001), the lumbar spine (L1-L5) gradually became less lordotic as the thoracic kyphosis increased (P < 0.003), and total lumbar lordosis was not age related. Sacral inclination correlated strongly with both thoracic kyphosis (P < 0.002) and L1-L5 lordosis (P < 0.001). Pelvic tilting correlated strongly with L1-L5 lordosis (P < 0.0075), but did not correlate with thoracic kyphosis and age. Vertebral body inclination showed a narrow variability in T6-T12 and in L4 and a wide variability in T4, T5, L1-L3, and S1. Distal lumbar lordosis represents the 68.6% of the total lumbar lordosis. In the results of this study, a reliable table of reference for roentgenographic parameters in the sagittal plane of the spine was established in an asymptomatic Greek population. The parameters are similar to those used in previous studies. Thus, these data should be considered in preoperative planning and postoperative evaluation of achieved correction during restoration procedures of the spine in the sagittal plane.

Lumbar lordosis. Effects of sitting and standing.

The effect of sitting versus standing posture on lumbar lordosis was studied retrospectively by radiographic analysis of 109 patients with low back pain. To document changes in segmental and total lumbar lordosis between sitting and standing radiographs. Preservation of physiologic lumbar lordosis is an important consideration when performing fusion of the lumbar spine. The appropriate degree of lumbar lordosis has not been defined. Total and segmental lumbar lordosis from L1 to S1 was assessed by an independent observer using the Cobb angle measurements of the lateral radiographs of the lumbar spine obtained with the patient in the sitting and standing positions. Lumbar lordosis averaged 49 degrees standing and 34 degrees sitting from L1 to S1, 47 degrees standing and 33 degrees sitting from L2 to S1, 31 degrees standing and 22 degrees sitting from L4 to S1, and 18 degrees standing and 15 degrees sitting from L5 to S1. Lumbar lordosis while standing was nearly 50% greater on average than sitting lumbar lordosis. The clinical significance of this data may pertain to: 1) the known correlation of increased intradiscal pressure with sitting, which may be caused by this decrease in lordosis; 2) the benefit of a sitting lumbar support that increases lordosis; and 3) the consideration of an appropriate degree of lordosis in fusion of the lumbar spine.

An Analysis of Sagittal Spinal Alignment in 100 Asymptomatic Middle and Older Aged Volunteers

A radiographic evaluation of 100 adult volunteers over age 40 and without a history of significant spinal abnormality was done to determine indices of sagittal spinal alignment. To determine the sagittal contours of the spine in a population of adults older than previously reported in the literature and to correlate age and overall sagittal balance to other measures of segmental spinal alignment. Previous studies of sagittal alignment have focused on adolescent and young adult populations before the onset of degenerative changes that may affect sagittal alignment. Radiographic measurements were collected and subjected to statistical analysis. Mean sagittal vertical axis fell 3.2 +/- 3.2 cm behind the front of the sacrum. Total lumbar lordosis (T12-S1) averaged -64 degrees +/- 10 degrees. Lordosis increased incrementally with distal progression through the lumbar spine. Lordosis at L5-S1 and the position of the apices of the thoracic and lumbar curves were most closely correlated to sagittal vertical axis. Increasing age correlated to a more forward sagittal vertical axis with loss of distal lumbar lordosis but without an increase in thoracic or thoracolumbar kyphosis. The majority of asymptomatic individuals are able to maintain their sagittal alignment despite advancing age. Loss of distal lumbar lordosis is most responsible for sagittal imbalance in those individuals who do not maintain sagittal alignment. Spinal fusion for deformity should take into account the anticipated loss of lordosis that may occur with age.

The Effect of Operative Position on Lumbar Lordosis

Study Design. The effect of intraoperative positioning on lumbar lordosis was retrospectively studied by radiographic analysis of 40 patients under general anesthesia. Objectives. The aim of this study was to document changes in segmental and total lumbar lordosis between preoperative standing and intraoperative radiographs taken in the “90-90” and prone positions. Summary of Background. Preservation of physiologic lordosis was an important consideration in reconstructive lumbar spine surgery. To avoid iatrogenic loss of lordosis when using spinal instrumentation and to facilitate decompressive procedures, it was necessary to understand how segmental alignments were affected by intraoperative positioning. Although many positioning techniques were used, the effect on lumbar lordosis was not well established. Methods. Preoperative (standing 36″ lateral spine) and intraoperative radiographs (lateral lumbar spine L1 to the sacrum) in either the “90-90” position on a Hastings frame (n = 20) or the prone position on a Jackson table (n = 20) were measured twice by two independent observers using Cobb methodology for total and segmental lordosis between L1 and S1. Data were analyzed for intra- and interobserver reliability and changes in segmental and total lordosis between standing and intraoperative radiographs. Results. Analysis of intra- and interobserver reliability revealed measurements were accurate and reproducible. The “90-90” position produced significant loss (P ≤ 0.01) of total and segmental lordosis at all levels except L1-L2, which showed no change. Segmental lordosis was reduced nearly 60% at L2-L3, L3-L4, and L4-L5, and total lordosis was reduced by more than 35%. The prone position on the Jackson table increased segmental lordosis at L5-S1 by 22% (P ≤ 0.01) and preserved total and segmental standing lordosis at all other levels. Conclusions. The “90-90” position on the Hastings frame was associated with significant reduction of total and segmental lordosis in the middle and lower lumbar spine. Positioning prone on a Jackson table maintained standing lumbar lordosis and increased lumbosacral lordosis.

An Analysis of Sagittal Spinal Alignment in 100 Asymptomatic Middle and Older Aged Volunteers

Study Design. A radiographic evaluation of 100 adult volunteers over age 40 and without a history of significant spinal abnormality was done to determine indices of sagittal spinal alignment. Objectives. To determine the sagittal contours of the spine in a population of adults older than previously reported in the literature and to correlate age and overall sagittal balance to other measures of segmental spinal alignment. Summary of Background Data. Previous studies of sagittal alignment have focused on adolescent and young adult populations before the onset of degenerative changes that may affect sagittal alignment. Methods. Radiographic measurements were collected and subjected to statistical analysis. Results. Mean sagittal vertical axis fell 3.2 ± 3.2 cm behind the front of the sacrum. Total lumbar lordosis (T12-S1) averaged −64° ± 10°. Lordosis increased incrementally with distal progression through the lumbar spine. Lordosis at L5-S1 and the position of the apices of the thoracic and lumbar curves were most closely correlated to sagittal vertical axis. Increasing age correlated to a more forward sagittal vertical axis with loss of distal lumbar lordosis but without an increase in thoracic or thoracolumbar kyphosis. Conclusions. The majority of asymptomatic individuals are able to maintain their sagittal alignment despite advancing age. Loss of distal lumbar lordosis is most responsible for sagittal imbalance in those individuals who do not maintain sagittal alignment. Spinal fusion for deformity should take into account the anticipated loss of lordosis that may occur with age.

Effect of Operative Position on Sagittal Alignment of the Lumbar Spine

A variety of techniques and frames are used for positioning patients during posterior lumbar spinal instrumentation and fusion. Little information is available on the relationship of lumbar lordosis and the various positioning options, so it was felt that further investigation was warranted. Ten volunteers with no history of back pain were positioned and radiographed in the standing position followed by four lateral radiographs with the patient positioned on chest rolls, Andrew's frame, the Hasting's frame, and a four-poster spinal frame. Total lumbar lordosis from L1 to S1 as well as intervertebral body angles at each of the lumbar interspaces using standardized techniques were computed. No significant difference was found in lumbar lordosis between the standing and chest roll position. However, there was approximately a 50% reduction in lumbar lordosis when using the Hasting's, Andrew's, and four-poster frame as compared to the standing and chest roll configuration. The clinical implications are discussed.

The effect of Harrington rod contouring on lumbar lordosis.

The effect of Harrington rod sagittal plane contouring, or lack of it, on total lumbar, segmental lumbar, and lumbosacral lordosis was studied retrospectively in a series of 36 patients operated on for idiopathic scoliosis. Regardless of contouring, there was a decrease in total lumbar lordosis and lordosis above L4, with an increase in lordosis below L5. Although not statistically significant, patients with contoured rods had less loss of segmental (L1-4) lordosis and less increase in segmental lumbosacral lordosis (L4-S1) than the noncontoured group. Although helpful, additional steps beyond concave rod contouring appear to be necessary to consistently preserve lumbar lordosis.