Sagittal Plane Lumbar Research Articles

Quantifying lumbar sagittal plane kinematics using a wrist-worn inertial measurement unit.

Wearable sensors like inertial measurement units (IMUs), and those available as smartphone or smartwatch applications, are increasingly used to quantify lumbar mobility. Currently, wearable sensors have to be placed on the back to measure lumbar mobility, meaning it cannot be used in unsupervised environments. This study aims to compare lumbar sagittal plane angles quantified from a wrist-worn against that of a lumbar-worn sensor. Twenty healthy participants were recruited. An IMU was placed on the right wrist and the L3 spinal level. Participants had to position their right forearm on their abdomen, parallel to the floor. Three sets of three consecutive repetitions of flexion, and extension were formed. Linear mixed models were performed to quantify the effect of region (lumbar vs. wrist) on six outcomes [minimum, maximum, range of motion (ROM) of flexion and extension]. Only flexion ROM was significantly different between the wrist and lumbar sensors, with a mean of 4.54° (95% CI = 1.82°-7.27°). Across all outcomes, the maximal difference between a wrist-worn and lumbar-worn sensor was <8°. A wrist-worn IMU sensor could be used to measure gross lumbar sagittal plane mobility in place of a lumbar-worn IMU. This may be useful for remote monitoring during rehabilitation.

Passive intervertebral restraint is different in patients with treatment-resistant chronic nonspecific low back pain: a retrospective cohort study and control comparison

PurposeIn vivo studies of continuous lumbar sagittal plane motion have found passive intervertebral motion to be more uneven in patients with chronic nonspecific low back pain (CNSLBP) than healthy controls, but the mechanisms are unclear. This study aimed to compare patients with CNSLBP with a matched group of pain-free controls for intervertebral restraint during passive recumbent bending.MethodsSeventeen patients with CNSLBP and minimal disc degeneration who had quantitative fluoroscopy investigations were matched to 17 healthy controls from a database acquired using the same imaging protocol. The entire database (n = 136) was examined for clustering of peaking times, magnitudes and ROM of the first derivatives of the intervertebral angle/motion curves (PTFD, PMFD and ROM) during flexion and return that might introduce confounding. The groups were then compared for differences in these variables.ResultsThere were significant segmental ROM differences among clusters in the database when PMFD and ROM were used as clustering variables, indicating heterogeneity. However, in the patient–control study, it was PTFD (velocity) that differentiated the groups. At L5-S1, this was at 10.82% of the motion path compared with 25.06% in the controls (p = 0.0002). For L4-5, PTFD was at 23.42% of the motion path in patients and 16.33% in controls (p = 0.0694) suggesting a reduced initial bending moment there. There were no significant differences for PMFD or ROM.ConclusionPeaking time of passive intervertebral velocity occurs early at L5-S1 in patients with CNSLBP; however, these findings should be treated with caution pending their replication. Future studies should explore relationships with altered disc pressures and biochemistry. Usefulness for monitoring regenerative disc therapies should be considered.

Development of a Machine Learning Model for the Estimation of Hip and Lumbar Angles in Ballet Dancers.

Accurate field-based assessment of dance kinematics is important to understand the etiology, and thus prevention and management, of hip and back pain. The study objective was to develop a machine learning model to estimate thigh elevation and lumbar sagittal plane angles during ballet leg lifting tasks, using wearable sensor data. Female dancers (n=30) performed ballet-specific leg lifting tasks to the front, side, and behind the body. Dancers wore six wearable sensors (100 Hz). Data were simultaneously collected using an 18-camera motion analysis system (250 Hz). Due to synchronization and hardware malfunction issues, only 23 dancers had usable data. Using leave-one-out cross-validation, machine learning models were compared with the optic motion capture system using root mean square error (RMSE) in degrees and correlation coefficients (r) over the complete movement profile of each leg lift and mean absolute error (MAE) and Bland Altman plots for peak angle accuracy. The average RMSE for model estimation was 6.8° for thigh elevation angle and 5.6° for lumbar spine sagittal plane angle, with respective MAE of 6.3°and 5.7°. There was a strong correlation between the machine learning model and optic motion capture for peak angle values (thigh r=0.86, lumbar r=0.96). The models developed demonstrated an acceptable degree of accuracy for the estimation of thigh elevation angle and lumbar spine sagittal plane angle during dance-specific leg lifting tasks. This provides potential for a near-real-time, field-based measurement system.

Consistent differences in lumbar spine alignment between low back pain subgroups and genders during clinical and functional activity sitting tests

BackgroundSubgroups of people with low back pain display differences in their lumbar alignment during tests from a clinical examination. However, it is unknown if subgroups display the same patterns during a functional activity test and if gender influences subgroup-related differences. ObjectivesTest if differences in lumbar alignment between two LBP subgroups are 1) present during a functional activity test of preferred sitting and 2) independent of gender. DesignCross-sectional. Method154 participants with chronic low back pain were classified based on the Movement System Impairment Classification System by a physical therapist. Participants performed a functional activity test of preferred sitting and clinical tests of maximum flexed and extended sitting. 3D marker co-ordinate data were collected. Sagittal plane lumbar alignment, indexed by lumbar curvature angle, was calculated. A three-way mixed effect analysis of variance was used to examine effects of test, subgroup, gender, subgroup × test, gender × test and subgroup × gender. Results/findingsThe lumbar rotation with extension subgroup [LCA = −8.0° (−9.5,-6.5)] displayed a more extended lumbar alignment than lumbar rotation [LCA = −5.9° (−7.4,-4.4)]. Women [LCA = −10.7° (−12.3,-9.2)] displayed a more extended lumbar alignment than men [LCA = −3.2° (−4.7,-1.7)]. There was a significant gender × test interaction (p = 0.01). The subgroup × test (p = 0.99) and subgroup × gender (p = 0.76) interactions were not significant. ConclusionsLBP subgroup differences in lumbar alignment are present during preferred sitting. Gender-related differences in lumbar alignment are not driving subgroup differences. These findings highlight the need to use patient-specific clinical characteristics to guide treatment of a functional activity of preferred sitting limited due to low back pain.

4188 Consistent Differences in Lumbar Spine Alignment Between Low Back Pain Subgroups and Sexes during Clinical and Functional Sitting Tests

OBJECTIVES/GOALS: Test the validity of a system for subgrouping people with CLBP by comparing lumbar spine alignment in two CLBP subgroups and sexes during clinical tests of maximum flexed and extended sitting and a functional test of preferred sitting. METHODS/STUDY POPULATION: Using the Movement System Impairment classification system, 154 participants with CLBP were subgrouped based on the predominant direction of altered movement and alignment patterns and symptoms during a standardized examination. Participants performed a functional test of preferred sitting followed by clinical tests of maximum flexed and extended sitting in random order. Reflective markers were place superficial to T12, L3 and S1 spinous processes. 3D marker co-ordinate data were collected using an 8 camera motion capture system. Sagittal plane lumbar curvature angle (LCA), defined as the angular distance between T12, L3, and S1 landmarks was calculated for each test. A three-way mixed effect ANOVA model was used to examine the following effects: test, subgroup, sex, test*subgroup, test*sex, subgroup*sex. RESULTS/ANTICIPATED RESULTS: Test: Lumbar alignment patterns were different for flexed [LCA = 7.4° (6.1, 8.7)], extended [LCA = −22.6° (−23.9,−21.3)], and preferred [LCA = −3.8° (−5.2,−2.5)] sitting tests. LBP subgroup: Rotation-extension [LCA = −7.5° (−8.7,−6.3)] had more extended lumbar alignment than rotation [LCA = −5.2° (−6.2,−4.2)]. Sex: Women had more extended lumbar alignment [LCA = −10.3° (−11.2,−9.3)] than men [LCA = −2.5° (−3.7,−1.2)]. Test*sex: The difference in lumbar alignment between women and men was smaller during the flexed sitting test [women = 4.2° (2.5, 5.9), men = 9.9° (7.8, 12.1)], compared to extended [women = −27.5° (−29.2, −25.8), men = −17.0° (−9.2, −14.8)] and preferred [women = −7.4° (−9.1, −5.8), men = −0.3° (−2.5, 1.8)]. The test*subgroup (p = 0.84) and subgroup*sex (p = 0.87) interactions were not significant.

Foot Arch Support Effect on Lumbo-Pelvic Kinematics and Centre of Pressure Excursion During Stand-to-Sit Transfer in Different Foot Types

Foot misalignments are possible risk factors for injuries to the knee and lumbar spine during daily activity. This study identified the lumbo-pelvic–knee kinematics and centre-of-pressure progression characteristics of the human trunk during stand-to-sit (STSI) transfer in people with different foot types. This study investigates the lower arch foot influence on lumbar–pelvic–knee kinematics and centre-of-pressure progression trunk characteristics during STSI transfer. Thirty-nine participants were assessed using the R-scan footscan system to define three different foot types (flat feet, normal feet, and asymmetric feet). Two electro goniometers and one inclinometer were used to record lumbar, pelvic and knee joint kinematic data during STSI transfer. A Tekscan mat system laced under the gluteal area was used to measure the trunk centre-of-pressure progression. The centre-of-pressure progression path, standard path deviation, velocity and acceleration were calculated. The flat foot group tended to use a more frontal plane range of motion and velocity in the pelvis than the normal group. The asymmetric foot group exhibited smaller sagittal plane lumbar motion and velocity, with a more frontal plane motion and velocity than normal participants. When arch support was used, the centre-of-pressure path standard deviation in the medial–lateral and anterior–posterior directions exhibited a significant decrease in all groups. There were no significant differences in kinematics, total centre-of-pressure path and centre-of-pressure progression acceleration between those with and without foot arch support. Participants with flat or asymmetric feet might have difficulty distributing the load forces evenly through both lower limbs and must use a different lumbar–pelvic strategy to compensate. Whether these adaptive kinematic strategies in the low arch group induce the development of injury requires further long-term investigation.

Measurement of lumbar spine intervertebral motion in the sagittal plane using videofluoroscopy.

Static radiographic techniques are unable to capture the wealth of kinematic information available from lumbar spine sagittal plane motion. Demonstration of a viable non-invasive technique for acquiring and quantifying intervertebral motion of the lumbar spine in the sagittal plane. Videofluoroscopic footage of sagittal plane lumbar spine flexion-extension in seven symptomatic volunteers (mean age = 48 yrs) and one asymptomatic volunteer (age = 54 yrs) was recorded. Vertebral bodies were digitised using customised software employing a novel vertebral digitisation scheme that was minimally affected by out-of-plane motion. Measurement errors in intervertebral rotation (± 1°) and intervertebral displacement (± 0.5 mm) compare favourably with the work of others. Some subjects presenting with an identical condition (disc prolapse) exhibited a similar column vertebral flexion-extension relative to S1 (L3: max. 5.9°, min. 5.6°), while in others (degenerative disc disease) there was paradoxically a significant variation in this measurement (L3: max. 28.1°, min. 0.7°). By means of a novel vertebral digitisation scheme and customised digitisation/analysis software, sagittal plane intervertebral motion data of the lumbar spine data has been successfully extracted from videofluoroscopic image sequences. Whilst the intervertebral motion signatures of subjects in this study differed significantly, the available sample size precluded the inference of any clinical trends.

Sagittal plane lumbar loading when navigating an obstacle and carrying a load

The current study quantified lumbar loading while carrying an anterior load mass and navigating an obstacle. Eight healthy male participants walked down a walkway and crossed an obstacle under three randomised LOAD conditions; empty-box (2 KG), five kilogram (5 KG) and ten kilogram (10 KG). Each walk was assessed at two events: left foot mid-stance (LMS) and right toe-crossing (TC) to characterise any changes from approach to crossing. Measures of interest included: trunk pitch, L4/L5 joint moment, compression, joint anterior–posterior shear and erector spinae activation. Findings demonstrate that obstacle crossing extended posture by 50, 41, 44%, respectively for each carried load magnitude. Further, these results indicate that shear rather than compressive loading may be an important consideration during crossing due to increase by 8, 9, 22% from LMS to TC for each load magnitude tested. These results provide insight into sagittal lumbar loading when navigating an obstacle while carrying a load.Practitioner Summary: The risk of carrying while navigating obstacles on the lumbar spine is not completely understood. The forces at the lumbar spine while simultaneously carrying and obstacle crossing were analysed. Data indicate that carrying and obstacle crossing influence lumbar shear loads, thereby moderately increasing the relative risk at lumbar spine.

Sagittal plane lumbar intervertebral motion during seated flexion-extension radiographs of 658 asymptomatic nondegenerated levels.

Evaluation of lumbar stability is fundamentally dependent on a clear understanding of normal lumbar motion. There are inconsistencies in reported lumbar motion across previously published studies, and it is unclear which provide the most reliable reference data. New technology now allows valid and reliable determination of normal lumbar intervertebral motion (IVM). The object of this study was to provide normative reference data for lumbar IVM and center of rotation (COR) using validated computer-assisted measurement tools. Sitting flexion-extension radiographs were obtained in 162 asymptomatic volunteers and then analyzed using a previously validated and widely used computerized image analysis method. Each lumbar level was subsequently classified as "degenerated" or "nondegenerated" using the Kellgren-Lawrence classification. Of the 803 levels analyzed, 658 were nondegenerated (Kellgren-Lawrence grade < 2). At each level of the lumbar spine, the magnitude of intervertebral rotation and translation, the ratio of translation per degree of rotation (TPDR), and the position of the COR were calculated in the nondegenerative cohort. Translations were calculated in millimeters and percentage endplate width. All parameters were significantly dependent on the intervertebral level. The upper limit of the 95% CIs for anteroposterior intervertebral translation in this asymptomatic cohort ranged from 2.1 mm (6.2% endplate width) to 4.6 mm (13.3% endplate width). Intervertebral rotation upper limits ranged from 16.3° to 23.5°. The upper limits for TPDR ranged from 0.49% to 0.82% endplate width/degree. The COR coordinates were clustered in level-dependent patterns. New normal values for IVM, COR, and the ratio of TPDR in asymptomatic nondegenerative lumbar levels are proposed, providing a reference for future interpretation of sagittal plane motion in the lumbar spine.

Development of a novel radiographic measure of lumbar instability and validation using the facet fluid sign.

Lumbar spinal instability is frequently referenced in clinical practice and the scientific literature despite the lack of a standard definition or validated radiographic test. The Quantitative Stability Index (QSI) is being developed as a novel objective test for sagittal plane lumbar instability. The QSI is calculated using lumbar flexion-extension radiographs. The goal of the current study was to use the facet fluid sign on MRI as the "gold standard" and determine if the QSI is significantly different in the presence of the fluid sign. Sixty-two paired preoperative MRI and flexion-extension exams were obtained from a large FDA IDE study. The MRI exams were assessed for the presence of a facet fluid sign, and the QSI was calculated from sagittal plane intervertebral rotation and translation measurements. The QSI is based on the translation per degree of rotation (TPDR) and is calculated as a Z-score. A QSI > 2 indicates that the TPDR is > 2 std dev above the mean for an asymptomatic and radiographically normal population. The reproducibility of the QSI was also tested. The mean difference between trained observers in the measured QSI was between -0.28 and 0.36. The average QSI was significantly (P = 0.047, one-way analysis of variance) higher at levels with a definite fluid sign (2.3±3.2 versus 0.60±2.4). Although imperfect, the facet fluid sign observed may be the best currently available test for lumbar spine instability. Using the facet fluid sign as the "gold standard" the current study documents that the QSI can be expected to be significantly higher in the presence of the facet fluid sign. This supports that QSI might be used to test for sagittal plane lumbar instability. A validated, objective and practical test for spinal instability would facilitate research to understand the importance of instability in diagnosis and treatment of low-back related disorders.

The reliability and validity of the computerized double inclinometer in measuring lumbar mobility.

Study Design : Repeated measures reliability/validity study.Objectives : To determine the concurrent validity, test-retest, inter-rater and intra-rater reliability of lumbar flexion and extension measurements using the Tracker M.E. computerized dual inclinometer (CDI) in comparison to the modified-modified Schober (MMS)Summary of Background : Numerous studies have evaluated the reliability and validity of the various methods of measuring spinal motion, but the results are inconsistent. Differences in equipment and techniques make it difficult to correlate results.Methods : Twenty subjects with back pain and twenty without back pain were selected through convenience sampling. Two examiners measured sagittal plane lumbar range of motion for each subject. Two separate tests with the CDI and one test with the MMS were conducted. Each test consisted of three trials. Instrument and examiner order was randomly assigned. Intra-class correlations (ICCs 2, 2 and 2, 2) and Pearson correlation coefficients (r) were used to calculate reliability and concurrent validity respectively.Results : Intra-trial reliability was high to very high for both the CDI (ICCs 0.85 - 0.96) and MMS (ICCs 0.84 - 0.98). However, the reliability was poor to moderate, when the CDI unit had to be repositioned either by the same rate (ICCs 0.16 - 0.59) or a different rater (ICCs 0.45 - 0.52). Inter-rater reliability for the MMS was moderate to high (ICCs 0.75 - 0.82) which bettered the moderate correlation obtained for the CDI (ICCs 0.45 - 0.52). Correlations between the CDI and MMS were poor for flexion (0.32; p<0.05) and poor to moderate (-0.42 - -0.51; p<0.05) for extension measurements.Conclusion : When using the CDI, an average of subsequent tests is required to obtain moderate reliability. The MMS was highly reliable than the CDI. The MMS and the CDI measure lumbar movement on a different metric that are not highly related to each other.

Hip Stiffness Patterns in Lumbar Flexion- or Extension-Based Movement Syndromes

ObjectiveTo determine whether a relationship exists between sagittal plane hip range of motion loss and sagittal plane lumbar Movement System Impairment (MSI) categories in patients with low back pain (LBP). DesignCorrelational study. SettingUniversity outpatient physical therapy clinic. ParticipantsSubjects (N=40) with LBP. InterventionsNot applicable. Main Outcome MeasuresClassification into a flexion- or extension-based lumbar MSI category, and bilateral passive hip flexion and extension range of motion testing. Using predefined criteria, subjects in each MSI category were subclassified into 1 of 3 hip stiffness categories: (1) a considerable loss of either flexion or extension (pattern A); (2) a considerable loss of both flexion and extension (pattern B); or (3) minimally limited flexion or extension (pattern C). ResultsPattern A occurred in 23 (57.5%) subjects, with the primary direction of hip motion loss agreeing with the MSI category 78.3% of the time (φ=.56; P=.007). Pattern B occurred in 10 (25%) subjects, with the primary direction of hip motion loss agreeing with the MSI category 70% of the time (φ=.47; P=.197). Pattern C occurred in 7 (17.5%) subjects, with the primary direction of hip motion limitation agreeing with the MSI category 42.9% of the time (φ=−.40; P=.290). ConclusionsConsiderable unidirectional hip motion loss in the sagittal plane was a common finding among subjects with LBP and yielded a strong positive relationship with the same direction MSI category. These results may inform future studies investigating whether treatment of hip stiffness patterns could improve outcomes in LBP management.

Change in Spinal Alignment after Total Hip Arthroplasty

The study hypotheses were that: (i) there would be a difference in sagittal plane alignment between patients with symptomatic osteoarthritis of the hip and those with lumbar degenerative disk disease; and (ii) that sagittal plane lumbar alignment would change following total hip arthroplasty (THA). In this prospective study, a series of patients without back pain or lumbar complaints who were scheduled to undergo THA underwent lateral lumbar radiography prior to and nine months after elective THA. Radiographic measurements of lumbar alignment included sacral slope, lumbar lordosis, and L1 axis S1 distance (L1 ASD). All measurements were performed on upright, standing, lateral radiographs. A control group of patients underwent serial radiography over the same period for evaluation of lumbar degenerative disease. The independent sample t-test was used to compare the mean sacral slope, lumbar lordosis, and L1 ASD in the THA and control groups. There were 12 patients in the THA group and 34 in the control group. Mean follow-up was 9 months. Average age in the control group was 63 years and in the THA group 64.2 years. The sacral slope was greater in the THA group (mean, 23°) than in the lumbar patients (control group) and this difference was statistically significant (mean, 11°, P = 0.001). There were no statistically significant differences between THA and control patients in lumbar lordosis or L1 ASD. Change before and after THA was measured. There were no statistically significant differences in assessed radiographic variables preoperatively versus postoperatively. There is no significant change in spinal alignment after unilateral THA. At baseline, patients with symptomatic spine complaints have less sacral slope than their hip arthroplasty counterparts.

Relationship between low back pain and lumbar sagittal alignment after lumbar fusion

To evaluate retrospectively the relationship between low back pain and changes of lumbar spine sagittal alignment after lumbar spine fusion. During January-December 2008, a total of 182 consecutive patients with degenerative lumbar spine diseases underwent posterior lumbar interbody fusion (PLIF) and the follow-up period was over 24 months. Standing lumbar spine anteroposterior and lateral radiography were taken during the follow-up and the lumbar lordosis Cobb angles were measured on radiography. Pain degrees were assessed by visual analog scale (VAS) and Oswestry disability index (ODI). The relationship between the changes of Cobb angle and lumbar sagittal plane curve was analyzed by the SPSS software. Also the relationship between back pain degree and Cobb angle was examined. Among them, 42 cases with postoperative back pain were followed up for 24 months. There were 19 males and 23 females with a mean age of 59.6 years (range: 40 - 77). Lumbar spine sagittal Cobb angles were measured from radiographic images:lumbar lordosis angle: (1) mean angle at 12-month follow-up: 40.1° ± 10.6°, range: 20° - 60°; (2) mean angle at 24-month follow-up: 40.8° ± 10°, range: 24° - 60°. Back pain of 42 patients: VAS: (1) mean at 12-month follow-up: 29.4 ± 11.5, range: 5 - 50; (2) mean at 24-month follow-up: 27.6 ± 11.7, range: 25 - 48. Lumbar spine function of 42 patients: ODI: (1) mean at 12-month follow-up: 15.1 ± 5.4, range: 0 - 25; (2) mean at 24-month follow-up: 13.9 ± 5.2, range: 0 - 24. Difference between lumbar lordosis angle and standard score: (1) mean angle at 12-month follow-up: 19.9° ± 10.6°, range:0°-40°; (2) mean angle at 24-month follow-up:19.2° ± 10.0°, range:0°-36°. Angle difference versus back pain VAS: (1) at 12-month follow-up:P < 0.001, positive correlation; (2) 24-month follow-up: P < 0.001, positive correlation; angle difference versus back pain ODI: (1) 12-month follow-up:P < 0.001, positive correlation; (2) 24-month follow-up: P < 0.001, positive correlation. There is a close relationship between back pain after fusion and loss of lumbar sagittal lordosis. And reconstruction of lumbar lordosis should be one important goal for lumbar fusion.

Segmental lumbar sagittal correction after bilateral transforaminal lumbar interbody fusion

In this paper the authors sought to determine the segmental lumbar sagittal contour change after bilateral transforaminal lumbar interbody fusion (TLIF). Between March 2007 and October 2010, 42 consecutive patients (57 levels) underwent bilateral TLIF. Standard preoperative and 6-week postoperative standing lumbar spine radiographs were examined. Preoperative and postoperative segmental lordosis was determined by manual measurements using the Cobb method. The difference between the preoperative and postoperative values were calculated and analyzed for statistical significance. The mean preoperative segmental alignment was 8.1°. The mean postoperative alignment was 15.3°, with a mean correction of 7.2° per segment. The largest gain in lordosis was obtained at the L5-S1 level (10.1°). There was a significant difference between the preoperative and postoperative values (p = 5 × 10(-9)). There was no significant difference in mean segmental correction between levels. Improvement in lordosis was higher in multilevel fusions (9.8°) than in single-level fusions (5.2°) (p = 0.047). There was an inverse correlation between preoperative sagittal lordosis measurement and change in lordosis (r = -0.599). A significant improvement in lumbar lordosis can be gained by preforming bilateral facetectomies in TLIF with posterior compression. This procedure provides an additional option to a spine surgeon's armamentarium in dealing with significant lumbar sagittal plane deformities.

Kinematics of lumbar spine motion in rowing during a fatiguing protocol: a comparison of ergometer and boat rowing

BackgroundThe incidence of lumbar spine injury is high. Ergometer rowing and fatigue have been cited as risk factors for this injury.ObjectiveCompare the kinematics of the lumbar spine in rowers on...

Changes in Radiographic and Clinical Outcomes With Primary Treatment Adult Spinal Deformity Surgeries From Two Years to Three- to Five-Years Follow-up

Retrospective analysis of data entered prospectively into a multicenter database-clinical and radiographic outcomes assessment. Our hypothesis is that between the 2-year and the 3- to 5-year points surgically treated adult spinal deformity patients will show significant reduction in outcomes by Scoliosis Research Society (SRS), Oswestry Disability Index (ODI), and numerical rating scale back and leg pain scores and will show increasing thoracic kyphosis, loss of lumbar lordosis, and loss of coronal and sagittal balance. Most analyses of primary presentation adult spinal deformity surgery assess 2-year follow-up. However, it is established that in some patients unfavorable events occur between the 2-year and 5-year points. The cohort of 113 patients entered into a multicenter database with complete preoperative, 2-year, and 3- to 5-year data. All patients who had adult spinal deformity and surgical treatment represented their first reconstruction. Diagnoses were scoliosis (82.5%), kyphosis (10%), and scoliosis and kyphosis combined (7.5%). Outcome measures and basic radiographic parameters (curve size, thoracic and lumbar sagittal plane, coronal and sagittal balance) were assessed at those 3 time intervals. Complications (pseudarthrosis/implant failure, infection, and junctional deformities) were assessed at the 2-year and the 3- to 5-year (mean, 3.76 years) points. RESULTS.: The mean major curve Cobb angle (preoperative, 57°; 2-year, 29°; 3-5 year, 26°); thoracic kyphosis T5 to T12 (30°, 31°, 32°) and lumbar lordosis T12 to sacrum (48°, 49°, 51°) did not change from the 2-year to ultimate follow-up. Likewise, coronal and sagittal balance parameters were the same at 2-year and ultimate follow-up. SRS total scores and modified ODI were similar at the 2 year and final follow-up (SRS: 3.89-3.88; ODI: 19-18). Preoperative SRS total score was 3.17. Six patients demonstrated complications at the 2-year point and additional 9 patients demonstrated complications at the 3- to 5-year point. Those 9 patients with complications at ultimate follow-up demonstrated significant deterioration in their ODI and SRS scores when compared with the patients who did not have complications at ultimate follow-up. Contrary to our hypothesis, we could not establish deterioration in mean radiographic or clinical outcomes between the 2-year and 3- to 5-year follow-up points when analyzing the group as a whole. However, for the 9 patients who experienced complications between 3- and 5-year follow-up, their outcomes were significantly worse than for the other 104 patients.One should not anticipate an overall radiographic and clinical deterioration of the outcomes of surgically treated primary presentation adult spinal deformity patients in this studied time interval. However, close to 10% of patients will experience a new complication at the 3- to 5-year point, most commonly implant failure/nonunion and/or junctional kyphosis, which will negatively effect the patient-reported outcome.

Sagittal Plane Lumbar Responses after Anterior Selective Thoracic Fusion for Main Thoracic Adolescent Idiopathic Scoliosis

Study DesignA retrospective radiographic study.PurposeTo verify the correlation of sagittal and coronal plane changes after selective thoracic fusion in main thoracic (MT) adolescent idiopathic scoliosis (AIS).Overview of LiteratureSagittal plane deformity is known to be essential in the evolution of scoliosis.MethodsTwenty-eight MT AIS patients treated by anterior selective thoracic fusion were evaluated after minimal follow-up of two years. The unfused lumbar area was divided into proximal and distal parts by the lumbar apex in the coronal plane, and into proximal and distal lumbar lordosis by L2 in the sagittal plane. Surgical motion (the difference between preoperative and postoperative values) and follow-up motion (the difference between postoperative and the last follow-up values) were compared.ResultsImmediately after surgery, as thoracic kyphosis increased, lumbar lordosis decreased (r=0.734); proximal lumbar lordosis increased, and distal lumbar lordosis decreased. The proximal lumbar area was mobilized in the sagittal plane, and was straightened in the coronal plane. However, the distal lumbar area was stabilized in the sagittal plane, and showed resistant motion against MT translation in the coronal plane. The surgical motion was correlated to the follow-up motion, i. e., was regulated during follow-up, and the regulatory motion was more precise in the distal than proximal lumbar area in both sagittal and coronal planes.ConclusionsSagittal and coronal motions were co-related; optimal sagittal motions were necessary for optimal coronal motions after anterior selective thoracic fusion for MT AIS. Proximal and distal lumbar motions were different for different roles; the proximal lumbar area played a role as a bumper to absorb the MT translatory force, and the distal lumbar area played a role of resistance against MT translation.

Biological risk indicators for recurrent non-specific low back pain in adolescents

Objectives: A matched case-control study was carried out to evaluate biological risk indicators for recurrent non-specific low back pain in adolescents. Methods: Adolescents with recurrent non-specific low back pain (symptomatic;...

Poster 152: Sagittal plane biomechanics and low back pain in transfemoral amputees.

Objectives: To document the extent of static lumbar lordosis and dynamic lumbar spine motion in the sagittal plane in transfemoral amputees and to determine whether excessive lumbar lordosis and excessive sagittal plane spine motion are related to low back pain (LBP) in transfemoral amputees. Design: A cross-sectional observational study. Setting: Motion analysis laboratory at a Veterans Affairs tertiary care facility. Participants: 6 ambulatory transfemoral amputees with a history of significant chronic LBP (CLBP) beginning after amputation and 3 ambulatory transfemoral amputees without history of CLBP since amputation. Interventions: Not applicable. Main Outcome Measures: L1-S1 Cobb angle from a lateral upright radiograph. Peak lumbar sagittal plane flexion and extension measured by a video-based motion analysis system. Results: The mean L1-S1 Cobb angle ± SD (range) were 62°±10° (44°–77°) for transfemoral amputees with LBP and 58°±3° (54°–61°) for transfemoral amputees without LBP. The mean maximum degrees of flexion (range) were 4.2°±5.9° (−8.0° to 13.7°) for transfemoral amputees with LBP and 3.0°±3.4° (−2.7° to 8.8°) for transfemoral amputees without LBP. The mean maximum degrees of extension (range) were −5.7°±6.4° (−21.0° to 2.3°) for transfemoral amputees with LBP and −5.9°±4.1° (−12.1° to 1.0°) for transfemoral amputees without LBP. Conclusions: The L1-S1 Cobb angle showed a significant relationship with LBP in transfemoral amputees ( P<.0313). The most extreme L1-S1 Cobb angles were seen in transfemoral amputees with LBP. There was no difference between the groups in either maximum lumbar flexion or extension ( P<0.3). From this data, static lumbar angles appear to be more related to LBP than the sagittal flexion and extension range of dynamic lumbar motion during gait; perhaps it is not the extremes of sagittal plane lumbar motion that place this population at risk. However, type II error cannot be excluded.