Measurements Of Lumbar Lordosis Research Articles

Comparative Analysis of Evaluation of Lumbar Lordosis Measured in the Standing Positions Radiography and Magnetic Resonance Imaging

Introduction Research of degenerative diseases of the spine it is recommended performing radiographs and magnetic resonance imaging (MRI). Physiological curvature of the lumbar spine varies from 35 to 50. Changes sagittal alignment can lead to changes in the lumbar spine kinematics, having influence on the support and load distribution on the spine, causing low back pain. Methods 100 patients with chronic low back pain (51 men and 49 women), being evaluated degree of lumbar lordosis by three independent examiners by radiography in the standing position and MRI in supine position with flexed lower limbs. Measurement of lumbar lordosis by the Cobb method (L1 to L5 levels) in lumbar radiographs in profile and in the sagittal plane in lumbar MRI. Results Average of lumbar curvature on X-rays and the MRI cushion was 42,2° and 31,5°, respectively (p value < 0.001). Average angles of lumbar lordosis by MRI underestimates by 25% compared with lumbar radiographs. Conclusion MRI is insufficient for evaluation of lumbar lordosis, it underestimates the true lumbar lordosis. Thus, the lumbar radiological evaluation is essential in assessing the true lumbar lordosis.

Lumbar Osteotomy.

When a patient presents with spine problems, the spine surgeon would do well to avoid use of, reliance on, and acceptance of radiographs as the sole or primary source of information. Measurement of pelvic incidence and lumbar lordosis, although crucial, does not take into account the effort the patient must make to move, the level of involvement of other parts of the body, and the history of previous procedures and outcomes. Radiographs may show pathology that is not consistent with the appearance of the patient. How should we assess this situation?

Differences between clinical “snap-shot” and “real-life” assessments of lumbar spine alignment and motion – What is the “real” lumbar lordosis of a human being?

The individual lumbar lordosis and lumbar motion have been identified to play an important role in pathogenesis of low back pain and are essential references for preoperative planning and postoperative evaluation. The clinical “gold-standard” for measuring lumbar lordosis and its motion are radiological “snap-shots” taken while standing and during upper-body flexion and extension. The extent to which these clinically assessed values characterise lumbar alignment and its motion in daily life merits discussion.A non-invasive measurement-system was employed to measure lumbar lordosis and lumbar motion in 208 volunteers (age: 20–74yrs; ♀/♂: 115/93). For an initial short-term measurement, comparable with the clinical “snap-shot”, lumbar lordosis and its motion were assessed while standing and during flexion and extension. Subsequently, volunteers were released to their daily lives while wearing the device, and measurements were performed during the following 24h.The average lumbar lordosis during 24h (8.0°) differed significantly from the standardised measurement while standing (33.3°). Ranges of motion were significantly different throughout the day compared to standing measurements. The influence of the factors age and gender on lordosis and its motion resulted in conflicting results between long- and short-term-measurements.In conclusion, results of short-term examinations differ considerably from the average values during real-life. These findings might be important for surgical planning and increase the awareness of the biomechanical challenges that spinal structures and implants face in real-life. Furthermore, long-term assessments of spinal alignment and motion during daily life can provide valid data on spinal function and can reveal the importance of influential factors.

Normal pediatric lumbar lordosis: Measurement of magnitude and age of maximum development using three radiographic techniques

Background: A retrospective measurement of lumbar lordosis (LL) in normal supine lateral lumbosacral spine radiographs of 27 children aged 0.04-14.00 years. Measurement of the LL may aid in the early diagnosis and management of some pediatric conditions before irreversible neurologic change occurs. They include spondylolisthesis (congenital or acquired); achondroplasia and muscular dystrophies are less common. The sagittal radiographic lumbar lordotic angle is poorly documented in normal pediatric population. Objective: To evaluate the magnitude and age of maximum development of the normal pediatric LL using three different radiographic techniques. Methods: Ferguson (for lumbosacral angle [LSA]), Cobb (for Cobb angle) and tangential radiologic assessment of LL (for TRALL angle) were the methods used. Data were analyzed with SPSS statistics version 20.0 (Chicago, IL, USA). P < 0.05 was considered significant. Results: LSA varied from 15° to 62°, Cobb angle 15-65° and TRALL angle 20-46°. The mean (standard deviation) of LSA, Cobb, and TRALL angles were 35.8 (10.3)°, 35.6 (13.7)°, and 32.3 (7.3),° respectively; the 0.95 confidence interval for the LSA was 27.6-44.5°, Cobb angle 27.2-50.7°, and TRALL angle 26.8-40.1°. Each angle showed no significant gender difference. The major part of estimated adult LL was gained during the first 5 years of life; the second peak occurred in the 11-14 years age-group. Conclusion: In children under 15 years, poor management of pathologies affecting LL can cause irreversible neurologic damage arising from spinal deformity.

New Predictive Index for Lumbar Paraspinal Muscle Degeneration Associated With Aging.

A cross-sectional imaging study of paraspinal muscle degeneration using a new index for easy evaluation. To examine the natural progression of age-related changes in the lumbar paraspinal muscles and to verify the validity of our new index for evaluating paraspinal muscle degenerationSUMMARY OF BACKGROUND DATA.: Measurement of paraspinal muscle morphology is an effective method for reflecting atrophy and fat infiltration, but it is complicated to perform. Therefore, we focused on the groove between lumbar paraspinal muscles as a simple index for evaluating paraspinal muscle degeneration. A total of 160 subjects aged 10 to 88 years (10 male and 10 female subjects in each decade) with lumbar lordosis of more than 20° were included. Body mass index (BMI) was calculated. Sagittal T2-weighted magnetic resonance imaging (MRI) was used to measure lumbar lordosis, while axial T2-weighted MRI was used to measure cross-sectional area (CSA) and fat infiltration rate of the paraspinal muscles at the intervertebral disc level from L1 to L5. To quantify the depth of the groove between the paraspinal muscles, our own image index (lumbar indentation value (LIV): equal to the length of the bulge of the muscle to the attachment of the spinous process), also was measured. We then determined the correlation between LIV and paraspinal muscle degeneration. There were no significant differences in BMI and lumbar lordosis between age groups. CSA of the paraspinal muscles tended to decrease with age, and fat infiltration rate increased with age. There was a negative correlation between CSA and fat infiltration rate at all levels (r = -0.474 to -0.634). LIV decreased significantly with age and strongly correlated with CSA at all levels (r = 0.709-0.789). Our new index is a simple and effective parameter for evaluating paraspinal muscle degeneration associated with aging. 4.

CHANGES IN RADIOGRAPHIC PARAMETERS AFTER MINIMALLY INVASIVE LUMBAR INTERBODY FUSION

Objective : This study aims to evaluate changes in lumbosacral parameters after minimally invasive lumbar interbody fusion. The secondary aim was to evaluate whether interbody cage shape (crescent shaped or rectangular) would influence the results. Method : Retrospective analysis of 70 patients who underwent one or two level lumbar interbody fusion through a minimally invasive posterolateral approach. This included midline preservation and unilateral facetectomy. Pre- and postoperative (three to six months postoperative) radiographs were used for measuring lumbar lordosis (LL), segmental lordosis (SL) at the level of interbody fusion, and sacral slope (SS). Further analyses divided the patients into Roussouly lumbar subgroups. Results : LL was significantly reduced after surgery (59o:39o, p=0.001) as well as the SS (33.8o:31.2o, p=0.05). SL did not change significantly (11.4:11.06, p=0.85). There were no significant differences when comparing patients who received crescent shaped cage (n=27) and rectangular cage (n=43). Hypolordotic patients (Roussouly types 1 and 2) had radiographic improvement in comparison to normolordotic and hyperlordotic groups (types 3 and 4). Conclusion : Minimally invasive lumbar interbody fusion caused reduction in lumbosacral parameters. Cage shape had no influence on the results.

Changes in Lumbosacral Radiographic Parameters after Minimally Invasive Lumbar Interbody Fusion

Introduction Modern techniques have allowed for less aggressive surgeries and faster postoperative recovery. This study aims to evaluate changes in lumbosacral parameters after minimally invasive lumbar interbody fusion. The secondary aim was to evaluate whether interbody cage shape (crescent or rectangular shape) would influence the results. Method This is a retrospective analysis of 70 patients who underwent one or two-level lumbar interbody fusion through a minimally invasive posterolateral approach. This included midline preservation and unilateral facetectomy. Pre- and postoperative (3–6 months postoperatively) radiographs were used for measuring lumbar lordosis (LL), segmental lordosis at the level of interbody fusion (SL), and sacral slope (SS). Further analyses divided the patients into Roussouly lumbar subgroups. Results LL was significantly reduced after surgery (59:39 degrees, p = 0.001) as well as the SS (33.8:31.2 degrees, p = 0.05). SL did not change significantly (11.4:11.06, p = 0.85). There were no significant differences when comparing patients who received crescent-shaped cage ( n = 27) and rectangular-shaped cage ( n = 43). Hypolordotic patients (Roussouly types 1 and 2) had radiographic improvement in comparison to normo and hyperlordotic groups (types 3 and 4). Conclusion Minimally invasive lumbar interbody fusion caused reduction in lumbosacral parameters. Hypolordotic patients showed improvement in radiographic measurements, in comparison to normo and hyperlordotic ones.

Validation of spinal sagittal alignment with plain radiographs and the Debrunner Kyphometer

Validation of the Debrunner Kyphometer as a clinical non-radiological method for investigating spinal sagittal alignment was compared with standing lateral radiographs. The sample group (n=102) consisted of elite Alpine skiers (n=75) and a non-athletic population (n=27), mean age 17.7 (±1.4) years. Non-radiological and radiological measurements of the spinal sagittal kyphosis and lordosis range of motion were carried out in the erect standing position. Thoracic kyphosis measurements comparing the Debrunner Kyphometer with a radiological standard, showed a good level of agreement and a statistical significance (ICC 0.67, 95% CI: 0.26 to 0.83, p<0.001). Lumbar lordosis measurements showed poor levels of agreement in spite of being statistically significant (ICC 0.33, 95% CI: 0.13 to 0.50, p=0.001). There was no significant difference reported in the spinal alignment between skiers and controls using both radiological and non-radiological methods. Therefore, we conclude that due to the large variation in ranges between both methods, there is a limited value in using the Debrunner Kyphometer as a non-invasive method for the evaluation of spinal sagittal alignment. Key words: Debrunner Kyphometer, kyphosis, lordosis, radiological, spinal sagittal alignment.

Sitting Sagittal Balance is Different From Standing Balance in Children With Scoliosis

Several variables can have effect on sagittal balance. The changes that occur between standing and sitting have been inadequately studied, especially in the, pediatric population. Preoperative sagittal radiographs were obtained in both standing and sitting positions for 26 patients with idiopathic scoliosis before spinal fusion and instrumentation. Standard measurements of thoracic kyphosis, lumbar lordosis, sacral slope (SS), pelvic incidence, pelvic tilt, and lumbar intervertebral angles were, recorded. Differences were compared between positions using 2-sided paired t tests. When moving from standing to a seated position, the spine loses 5-degree thoracic kyphosis (P=0.007), 29-degree lumbar lordosis (P<0.0001), and the sacrum rotates 20 degrees (P<0.0001) to a more vertical position. The greatest change in sitting sagittal balance occurs due to increased pelvic tilt with decreased SS. The next greatest change is increased forward flexion of the lowest 2 lumbar vertebrae, 6.5 degrees between L4-L5 (P<0.0001) and 5.9 degrees between L5-S1 (P<0.0001). Flexion occurs throughout the lumbar spine but its magnitude decreases in the more proximal lumbar segments, 1.6 degrees between L1-L2 (P=0.028). The sagittal vertical axis also moves more anterior by 44 mm (P<0.0001). Sitting significantly straightens the spine with decreases of thoracic kyphosis, lumbar lordosis, and SS. The majority of the changes occur in the lumbar spine and pelvis. As humans spend much of their time sitting, this difference should be considered when spinal instrumentation is performed. These findings may be important to those who only sit, especially when instrumentation is extended to the pelvis. Level II--retrospective prognostic study.

Segmental and global lordosis changes with two-level axial lumbar interbody fusion and posterior instrumentation.

BackgroundLoss of lumbar lordosis has been reported after lumbar interbody fusion surgery and may portend poor clinical and radiographic outcome. The objective of this research was to measure changes in segmental and global lumbar lordosis in patients treated with presacral axial L4-S1 interbody fusion and posterior instrumentation and to determine if these changes influenced patient outcomes.MethodsWe performed a retrospective, multi-center review of prospectively collected data in 58 consecutive patients with disabling lumbar pain and radiculopathy unresponsive to nonsurgical treatment who underwent L4-S1 interbody fusion with the AxiaLIF two-level system (Baxano Surgical, Raleigh NC). Main outcomes included back pain severity, Oswestry Disability Index (ODI), Odom's outcome criteria, and fusion status using flexion and extension radiographs and computed tomography scans. Segmental (L4-S1) and global (L1-S1) lumbar lordosis measurements were made using standing lateral radiographs. All patients were followed for at least 24 months (mean: 29 months, range 24-56 months).ResultsThere was no bowel injury, vascular injury, deep infection, neurologic complication or implant failure. Mean back pain severity improved from 7.8±1.7 at baseline to 3.3±2.6 at 2 years (p < 0.001). Mean ODI scores improved from 60±15% at baseline to 34±27% at 2 years (p < 0.001). At final follow-up, 83% of patients were rated as good or excellent using Odom's criteria. Interbody fusion was observed in 111 (96%) of 116 treated interspaces. Maintenance of lordosis, defined as a change in Cobb angle ≤ 5°, was identified in 84% of patients at L4-S1 and 81% of patients at L1-S1. Patients with loss or gain in segmental or global lordosis experienced similar 2-year outcomes versus those with less than a 5° change.Conclusions/Clinical RelevanceTwo-level axial interbody fusion supplemented with posterior fixation does not alter segmental or global lordosis in most patients. Patients with postoperative change in lordosis greater than 5° have similarly favorable long-term clinical outcomes and fusion rates compared to patients with less than 5° lordosis change.

Measurement of lumbosacral angle in normal radiographs: a retrospective study in southeast Nigeria.

Background:A retrospective study of lumbosacral angle (LSA) in normal lateral supine lumbosacral radiographs of 274 Nigerians (aged 15-74 years) of Southeast region. A supine lateral lumbar spine radiograph is a very accurate means of measuring lordotic angles. The LSA is one of such angles, and can be used in the investigation, treatment and follow-up of low back disorders. Little is known about what the normal value for our population is and therefore, what constitutes hypo-/hyper-lordosis; most of the data in use in medical practice are based on studies on other races.Aim:To quantify the normal LSA in our population.Materials and Methods:LSA was measured by the Ferguson's technique and the data analyzed with SPSS Statistics version 17.0 (Chicago IL, USA).Results:LSA varied between 18° and 71°. With a 95.0 confidence interval of 43.3-45.6°, the mean (standard deviation) was 44.5 (9.9)° and showed no significant variation with sex and between various age groups; it compared favorably (though with small difference) with some of the literature values currently in use.Conclusion:This study had established the normal lordosis and the possible values at which to consider hypo-lordosis (below 15°), and hyper-lordosis (above 75°) in our population. Also established is that the development of lumbar lordosis ceases at spinal maturity, and that in normal lumbar lordosis measurement, the retrospective approach is a credible alternative to the prospective method.

Lumbar lordosis

Lumbar lordosis is a key postural component that has interested both clinicians and researchers for many years. Despite its wide use in assessing postural abnormalities, there remain many unanswered questions regarding lumbar lordosis measurements. Therefore, in this article we reviewed different factors associated with the lordosis angle based on existing literature and determined normal values of lordosis. We reviewed more than 120 articles that measure and describe the different factors associated with the lumbar lordosis angle. Because of a variety of factors influencing the evaluation of lumbar lordosis such as how to position the patient and the number of vertebrae included in the calculation, we recommend establishing a uniform method of evaluating the lordosis angle. Based on our review, it seems that the optimal position for radiologic measurement of lordosis is standing with arms supported while shoulders are flexed at a 30° angle. There is evidence that many factors, such as age, gender, body mass index, ethnicity, and sport, may affect the lordosis angle, making it difficult to determine uniform normal values. Normal lordosis should be determined based on the specific characteristics of each individual; we therefore presented normal lordosis values for different groups/populations. There is also evidence that the lumbar lordosis angle is positively and significantly associated with spondylolysis and isthmic spondylolisthesis. However, no association has been found with other spinal degenerative features. Inconclusive evidence exists for association between lordosis and low back pain. Additional studies are needed to evaluate these associations. The optimal lordotic range remains unknown and may be related to a variety of individual factors such as weight, activity, muscular strength, and flexibility of the spine and lower extremities.

The reliability, minimal detectable change and concurrent validity of a gravity-based bubble inclinometer and iphone application for measuring standing lumbar lordosis

Purpose: To investigate the reliability, minimal detectable change (MDC90) and concurrent validity of a gravity-based bubble inclinometer (inclinometer) and iPhone® application for measuring standing lumbar lordosis. Methods: Two investigators used both an inclinometer and an iPhone® with an inclinometer application to measure lumbar lordosis of 30 asymptomatic participants. Results: ICC models 3,k and 2,k were used for the intrarater and interrater analysis, respectively. Good interrater and intrarater reliability was present for the inclinometer with Intraclass Correlation Coefficients (ICC) of 0.90 and 0.85, respectively and the iPhone® application with ICC values of 0.96 and 0.81. The minimal detectable change (MDC90) indicates that a change greater than or equal to 7° and 6° is needed to exceed the threshold of error using the iPhone® and inclinometer, respectively. The concurrent validity between the two instruments was good with a Pearson product-moment coefficient of correlation (r) of 0.86 for both raters. Ninety-five percent limits of agreement identified differences ranging from 9° greater in regards to the iPhone® to 8° less regarding the inclinometer. Conclusion: Both the inclinometer and iPhone® application possess good interrater reliability, intrarater reliability and concurrent validity for measuring standing lumbar lordosis. This investigation provides preliminary evidence to suggest that smart phone applications may offer clinical utility comparable to inclinometry for quantifying standing lumbar lordosis. Clinicians should recognize potential individual differences when using these devices interchangeably.

Sagittale Balance und Kompensationsmechanismen nach operativer Versorgung bei idiopathischer Skoliose mittels segmentaler Pedikelschraubeninstrumentation

Previous studies have demonstrated good ability to improve the sagittal profile with the use of segmental instrumentation for adolescent idiopathic scoliosis (AIS) by analysing the sagittal vertical axis (SVA). However, several authors recommend analysing the spinopelvic relation in addition to the SVA. While compensatory mechanisms may neutralise a positive SVA, these mechanisms are energy consuming and may lead to unphysiological biomechanics, which can negatively influence the quality of life. The purpose of this radiographic analysis was to analyse global sagittal balance and to identify potential compensatory mechanisms after segmental instrumentation for AIS. From a prospectively collected multicentre database, patients with segmental instrumentation for AIS and a minimum follow-up of 2 years were identified. An additional inclusion criterion was the ability to measure lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), and SVA on each X-ray (preoperative, 1st erect, and the 2-year follow-up visits). LL was analysed in relation to PI in order to identify iatrogenic changes. Changes in LL were correlated to changes in PT and SVA. 91 patients were included. On the 1st erect X-ray, LL significantly decreased from pre-op but the SVA remained stable due to a significant increase of PT. At two years follow-up, PT recurred to preoperative values, accompanied by a significant increase of SVA despite a compensatory hyperlordosis below the instrumentation. The temporary increase of PT on the 1st erect was significantly correlated to an iatrogenic decrease of LL. An iatrogenic decrease of LL was significantly correlated to an increase of SVA on the 1st erect and at 2 years follow-up. An iatrogenic decrease of LL after segmental instrumentation for AIS is initially compensated for by pelvic retroversion and later by a hyperlordosis below the instrumentation.

Radiographic measurement reliability of lumbar lordosis in ankylosing spondylitis

Intraobserver and interobserver reliabilities of the several different methods to measure lumbar lordosis have been reported. However, it has not been studied sofar in patients with ankylosing spondylitis (AS). We evaluated the inter and intraobserver reliabilities of six specific measures of global lumbar lordosis in patients with AS. Ninety-one consecutive patients with AS who met the most recently modified New York criteria were enrolled and underwent anteroposterior and lateral radiographs of whole spine. The radiographs were divided into non-ankylosis (no bony bridge in the lumbar spine), incomplete ankylosis (lumbar spines were partially connected by bony bridge) and complete ankylosis groups to evaluate the reliability of the Cobb L1-S1, Cobb L1-L5, centroid, posterior tangent L1-S1, posterior tangent L1-L5, and TRALL methods. The radiographs were composed of 39 non-ankylosis, 27 incomplete ankylosis and 25 complete ankylosis. Intra- and inter-class correlation coefficients (ICCs) of all six methods were generally high. The ICCs were all ≥0.77 (excellent) for the six radiographic methods in the combined group. However, a comparison of the ICCs, 95 % confidence intervals and mean absolute difference (MAD) between groups with varying degrees of ankylosis showed that the reliability of the lordosis measurements decreased in proportion to the severity of ankylosis. The Cobb L1-S1, Cobb L1-L5 and posterior tangent L1-S1 method demonstrated higher ICCs for both inter and intraobserver comparisons and the other methods showed lower ICCs in all groups. The intraobserver MAD was similar in the Cobb L1-S1 and Cobb L1-L5 (2.7°-4.3°), but the other methods showed higher intraobserver MAD. Interobserver MAD of Cobb L1-L5 only showed low in all group. These results are the first to provide a reliability analysis of different global lumbar lordosis measurement methods in AS. The findings in this study demonstrated that the Cobb L1-L5 method is reliable for measuring the global lumbar lordosis in AS.

Reliability of Measuring Thoracic Kyphosis Angle, Lumbar Lordosis Angle and Straight Leg Raise with an Inclinometer

Purpose: Several non-invasive measurement methods have been described in the literature for recording thoracic kyphosis, lumbar lordosis and straight leg raise (SLR). However, attempts to quantify the reliability of the inclinometer in these measurements are scarce. In addition, existing reliability studies within the literature were found to use small sample sizes. The aim of this investigation was to examine the intra-rater reliability of the chief investigator (SM), in order to provide clinicians with data that will allow them to better measure sagittal spinal posture and SLR. A blinded test-retest design was performed to determine the intra-rater reliability of thoracic kyphosis, lumbar lordosis and SLR when assessed using an Isomed inclinometer in normals. Methods. Thirty asymptomatic subjects were assessed on two occasions separated by a time interval of 1 hour to reduce investigator memory bias. Thoracic and lumbar measurements were recorded in a relaxed standing position using an inclinometer; SLR of the dominant leg was assessed with subjects in the supine position. Intraclass correlation coefficients (ICC), 95% confidence intervals (CI), and standard errors of measurement (SEM) were analysed to determine measurement reliability. Results. The chief investigator demonstrated excellent intra-rater reliability in the measurements of thoracic kyphosis, lumbar lordosis and SLR. ICC (2,3) values for all three variables exceeded the 0.90 threshold suggesting that the reliability of these measures are acceptable for clinical application. Conclusions. The inclinometer technique employed in this study to record thoracic kyphosis, lumbar lordosis and SLR is a reliable measurement method.

Measurement of lumbar lordosis in static standing posture with and without high-heeled shoes

ObjectiveSome doctors and therapists believe that wearing high-heeled shoes causes increased lumbar lordosis and that this may be a cause of low back pain. The purpose of this study was to evaluate whether high-heeled shoes increase lumbar lordosis and to do so with more reliable methods and a larger sample size than used in previous studies. MethodsFifty participants from a chiropractic university were included in a test group (32 female and 18 male) and 9 in a control group (3 female and 6 male). A Spinal Mouse was used to measure lumbar lordosis in test participants barefoot and then again with 3- or 4-in high-heeled shoes after a 10-minute adaptation period of walking and sitting and standing while wearing the shoes. Reliability of the testing conditions was evaluated with 9 barefoot control participants before and after an identical adaptation period, and intra- and interexaminer reliability of Spinal Mouse measurements was tested by use of a wooden model built to mimic the proportions of a human spine. ResultsBoth groups showed non-significant decreases in lordosis between the first and second scans (high heels: 23.4° to 22.8°, P = .17; control: 18.8° to 17.6°, P = .16). Scans of the wooden spine model were highly reliable (intra- and interexaminer intraclass correlation coefficients > .999). ConclusionsConsistent with most previous studies, high-heeled shoes did not affect lumbar lordosis in most people while standing. Future research could investigate the effect of shoes during dynamic conditions or identify affected subgroups.

The assessment of the postoperative spinal alignment: MRI adds up on accuracy

The sagittal profile of conventionally and surgically treated scoliotic spines is usually analyzed via lateral views of whole-spine X-rays in an upright position. Due to a more hypokyphotic configuration of scoliotic spines, the view onto the upper thoracic vertebrae is often difficult. We investigated whether additional supine MRI measurement supports valid kyphosis angle measurement. Twenty patients with either short (n=10, Halm-Zielke, VDS) or long spondylodesis (n=10, dorsoventral) were assessed 5years after surgery with standing radiographs and supine whole-spine MRI. Up to 90% of the upper thoracic vertebrae were invisible on radiographs, whereas MRI allowed visibility of almost many vertebrae. No significant difference in thoracal kyphosis angles could be observed in the comparison of X-ray and MRI data. Thoracal kyphosis measurement of postoperative spines in MRI is a valid diagnostic tool with reliability comparable to that of X-ray. These results cannot be transferred to lumbar lordosis measurement and transferred only partly to coronal COBB angle measurement.

Reliability and validity of the AutoCAD software method in lumbar lordosis measurement

Objective The aim of this study was to determine the reliability and validity of the AutoCAD software method in lumbar lordosis measurement. Methods Fifty healthy volunteers with a mean age of 23 ± 1.80 years were enrolled. A lumbar lateral radiograph was taken on all participants, and the lordosis was measured according to the Cobb method. Afterward, the lumbar lordosis degree was measured via AutoCAD software and flexible ruler methods. The current study is accomplished in 2 parts: intratester and intertester evaluations of reliability as well as the validity of the flexible ruler and software methods. Results Based on the intraclass correlation coefficient, AutoCAD's reliability and validity in measuring lumbar lordosis were 0.984 and 0.962, respectively. Conclusions AutoCAD showed to be a reliable and valid method to measure lordosis. It is suggested that this method may replace those that are costly and involve health risks, such as radiography, in evaluating lumbar lordosis.

Lumbo-pelvic lordosis and the pelvic radius technique in the assessment of spinal sagittal balance: strengths and caveats

The two main methodologies described for the assessment of spinal sagittal alignment are the pelvic radius (PR) technique and that based on measures of the Pelvic Incidence (PI) and Spino-Sacral Angle (SSA). Both methods stress the fundamental relationship between the anatomical position and orientation of the sacrum within the pelvis and the spinal curves above. The aim of the current study was to assess the strengths and potential weaknesses of the PR technique. The PR technique uses measures based on a line (the PR), drawn between the hip axis and the posterior corner of the S1 endplate. The angle formed between the PR line and the sacral endplate, PRS1, is a developmental measure of sacropelvic morphology. Geometrically, PI and PRS1 are approximately complementary angles and both reflect reciprocal alterations in pelvic tilt (for PI) or angulation (for PRS1) and the slope of the S1 endplate. The angle formed between PR and T12, the PR-T12, reflects a combined measure of pelvic morphology and lumbar lordosis. It appears to be a useful measure, which provides a simple and rapid assessment of lumbopelvic sagittal balance, but only in the presence of a congruent thoracic curvature. After reviewing the literature, published measures made using the PR technique were compared to measures taken from a substantial patient population (479 adult patients). Errors can occur using the PR technique if the PRT12 is viewed in isolation from the thoracic kyphosis. We found the ratio of the thoracic kyphosis to lumbar lordosis (T4-T12/T12-S1) to be a useful predictor of congruent sagittal alignment, which may alert the clinician to situations where use of the PR-T12 in isolation may be misleading.