Standing Lumbar Lordosis Research Articles

The change in lumbar lordosis from the standing to the lateral position: implications for lateral interbody fusion.

The purpose of this cross-sectional, observational study was to establish the relationship between standing lumbar lordosis (LL) and lateral decubitus LL. Forty-nine subjects, 24 male and 25 female, were prospectively enrolled. Patients with pre-existing spinopelvic pathology were excluded. Standing, relaxed-seated, and lateral decubitus lateral radiographs were obtained. Radiographic variables measured included LL and lordosis change at each lumbar level (e.g. L1-L2). The change in LL when going from a standing to a lateral decubitus position (ΔLL), the correlation between standing and sitting LL compared to lateral decubitus LL, and the correlation between ΔLL and standing pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch, pelvic femoral angle (PFA), and sacral slope (SS) were calculated. Subjects had an average age of 25.7 ± 2.3 years and body mass index of 24.1 ± 3.0kg/m2. On average, 11.9°±8.2° (range - 7° to 29°) of LL was lost when transitioning from a standing to the lateral decubitus position. Lateral decubitus LL had a higher correlation with standing LL (R = 0.725, p < 0.001) than with relaxed-seated LL (R = 0.434, p < 0.001). Standing PT and PI-LL mismatch had moderately negative correlations with ΔLL (R=-0.58 and R=-0.59, respectively, both p < 0.05). Standing PI and standing PFA had a low negative correlation with ΔLL (R=-0.31 and R=-0.44, respectively, both p < 0.05) Standing SS and LL had no correlation with ΔLL. Standing LL was strongly correlated to lateral decubitus LL, although subjects lost an average of 11.9° from the standing to the lateral decubitus position. This has important implications for fusion in the lateral position.

How Does Radiographic Acetabular Morphology Change Between the Supine and Standing Positions in Asymptomatic Volunteers?

The radiographic appearance of the acetabulum differs between the supine and standing positions in patients with hip conditions. The pelvis undergoes a change in tilt when transitioning between positions, resulting in variations in version and acetabular coverage. However, the extent of these variations in well-functioning volunteers without compensatory patterns caused by pain is unknown. We performed this study to (1) quantify differences in radiographic acetabular measurements when transitioning between supine and standing among asymptomatic, well-functioning volunteers; (2) assess differences in pelvic tilt between positions; and (3) test whether individual anatomic parameters are associated with the change in tilt. This was a prospective, single-center study performed at an academic referral center. One hundred volunteers (students, staff, and patients with upper limb injuries) with well-functioning hips (Oxford hip score ≥ 45) were invited to participate. A total of 45% (45) of them were female, their mean age was 37 ± 14 years, and their mean BMI was 25 ± 2 kg/m 2 . Supine and standing AP pelvic radiographs were analyzed to determine numerous acetabular parameters including the lateral center-edge angle (LCEA), acetabular index (AI), anterior wall index (AWI), posterior wall index (PWI), crossover sign (COS), crossover ratio (COR), posterior wall sign (PWS), ischial spine sign (ISS), and femoroepiphyseal acetabular roof index (FEAR), as well as pelvic parameters including the sacrofemoral-pubic angle (SFP). Spinopelvic parameters were measured from lateral standing spinopelvic radiographs. Radiographic measurements were performed by one hip preservation research fellow and a fellowship-trained staff surgeon. Differences in parameters were determined, and correlations between postural differences and morphological parameters were tested. Clinically important differences were defined as a difference greater than 3° for acetabular angle measurements and 0.03 for acetabular ratio measurements, based on previous studies. Lateral coverage angles did not show a clinically important difference between positions. AWI decreased when standing (0.47 ± 0.13 versus 0.41 ± 0.14; p < 0.001), whereas acetabular retroversion signs were more pronounced when supine (COS: 34% [34 of 100], PWS: 68% [68 of 100], and ISS: 34% [34 of 100] versus COS: 19% [19 of 100], PWS: 38% [38 of 100], and ISS: 14% [14 of 100]; all p values < 0.05). Pelvic tilt increased by a mean of 4° ± 4° when standing, but the range of change was from -15° to 7°. The change in AWI (ρ = 0.47; p < 0.001), PWI (ρ = -0.45; p < 0.001), and COR (ρ = 0.52; p < 0.001) between positions correlated with ΔSFP. Volunteers with spinal imbalance (pelvic incidence lumbar lordosis > 10°) demonstrated greater change in pelvic tilt (ΔSFP) (-7° ± 3° versus -4° ± 4°; p = 0.02) and a greater reduction in AWI (by 10%). These volunteers demonstrated reduced standing lumbar lordosis angles (45° ± 11° versus 61° ± 10°; p = 0.001). Acetabular version increases from supine to standing because of an increase in pelvic tilt. The change in pelvic tilt between positions exhibited substantial variability. Individuals with reduced lumbar lordosis for a given pelvic incidence value demonstrated greater pelvic mobility. No features on supine radiographs were associated with the change in tilt. Performing standing radiographs in addition to supine views can help identify aberrant physiologic patterns in patients with diagnostic dilemmas and might thus help with management. Normative data of pelvic tilt change can help clinicians identify patients who demonstrate excessive change in tilt that contributes to abnormal hip pathomechanics.

How Do Spinopelvic Characteristics Change Post-Total Hip Arthroplasty? A Longitudinal Assessment Raising Awareness of the Postoperative Period

BackgroundSpinopelvic characteristics, including sacral slope (SS), are commonly evaluated in different positions pre-total hip arthroplasty (THA). This study aimed to: 1) investigate the change in spinopelvic parameters at 7 days (early) and 1-year post-THA; and 2) identify patient characteristics associated with a change in SS of more than 7° post-THA. MethodsWe prospectively studied 250 patients who underwent unilateral THA [132 women, age 66 years (range, 32 to 88)] and underwent biplanar images preoperatively and at 7 days and 1-year post-THA. Parameters measured included pelvic incidence, standing lumbar lordosis, SS, and proximal femoral angle (PFA). A SS change ≥ 7° was considered the threshold as it would result in more than a 5° change in cup orientation. ResultsEarly post-THA SSstanding remained within ± 6º from preoperative measurements in 75% of patients, reduced by ≥ 7° in 9%, and increased by ≥ 7° in 16%. Those that showed a reduction in SS had the lowest PFA and the highest SS pre-THA (P = .028, .107, and < 0.001, respectively). From 7 days until the 1-year mark, pelvic tilt increased, SS reduced (mean: -4º, range: −29 to 17º, P < .001), and patients stood with greater hip extension ΔPFAstanding (mean 7°, range: −34 to 37°, P < .001). At 1 year, SSseated had remained within ± 6º, relative to the pre-THA value, in 49% of patients. ConclusionsStanding spinopelvic characteristics, especially SSstanding, remain within ±6° in three-quarters of patients both early- and at 1-year post-THA. In the remaining cases, pelvic tilt changes significantly. In 9% of cases, SS reduces ≥ 7° early THA, probably due to the alleviation of fixed-flexion contractures. The SSseated changes by ≥ ± 7° in almost 50% of cases in this study, and its clinical value as a preoperative planning tool should be questioned. Level of EvidenceLevel II, diagnostic study.

Prolonged Standing-Induced Low Back Pain Is Linked to Extended Lumbar Spine Postures: A Study Linking Lumped Lumbar Spine Passive Stiffness to Standing Posture.

Postural assessments of the lumbar spine lack valuable information about its properties. The purpose of this study was to assess neutral zone (NZ) characteristics via in vivo lumbar spine passive stiffness and relate NZ characteristics to standing lumbar lordosis. A comparison was made between those that develop low back pain during prolonged standing (pain developers) and those that do not (nonpain developers). Twenty-two participants with known pain status stood on level ground, and median lumbar lordosis angle was calculated. Participants were then placed in a near-frictionless jig to characterize their passive stiffness curve and location of their NZ. Overall, both pain developers and nonpain developers stood with a lumbar lordosis angle that was more extended than their NZ boundary. Pain developers stood slightly more extended (in comparison to nonpain developers) and had a lower moment corresponding to the location of their extension NZ boundary. Overall, in comparison to nonpain developers, pain developers displayed a lower moment corresponding to the location of their extension NZ boundary which could correspond to greater laxity in the lumbar spine. This may indicate why pain developers have a tendency to stand further beyond their NZ with greater muscle co-contraction.

How to Screen for Lumbar Spine Stiffness in Patients Awaiting Total Hip Arthroplasty

BackgroundThis study aimed to (1) define the prevalence of spinopelvic abnormalities among patients who have hip osteoarthritis (OA) and controls (asymptomatic volunteers) and (2) identify factors that reliably predict the presence of lumbar spine stiffness. MethodsThis is a prospective, cross-sectional, case-cohort study of patients who have end-stage primary hip OA, who underwent primary total hip arthroplasty (THA). Patients were compared with a cohort of asymptomatic volunteers, matched for age, sex, and body mass index (BMI), serving as a control group. Spinopelvic pathologies were defined as: lumbar spine flatback deformity (difference of 10 or more degrees for pelvic incidence minus lumbar lordosis angle), a standing sagittal pelvic tilt of 19° or more and lumbar spine stiffness (lumbar flexion of less than 20° between both postures). ResultsThe prevalence of spinopelvic pathologies was similar between patients and controls (flatback deformity: 16% versus 10%, P = .209; standing pelvic tilt >19°: 17% versus 24%, P = .218; lumbar spine stiffness: 6% versus 5%, P = .827). Age over 65 years-old and standing lumbar lordosis angle less than 45° were associated with high sensitivity and specificity for identifying lumbar spine stiffness (age >65 years: 82% and 66%; standing lumbar lordosis angle <45°: 85% and 73%). ConclusionThe presence of end-stage hip osteoarthritis was not associated with increased prevalence of adverse spinopelvic characteristics compared to matched, asymptomatic volunteers. Age and LLstanding are the strongest predictors of lumbar spine flexion and can guide clinical practice on when to obtain additional radiographs for patients who have hip OA before arthroplasty to identify at-risk patients. Level of EvidenceII (prospective, cohort study).

Immediate Effects of Isolated Lumbar Extension Resistance Exercise (ILEX) on Spine Posture and Mobility Measured with the IDIAG Spinal Mouse System.

Posture and mobility are important aspects for spinal health. In the context of low back pain, strategies to alter postural anomalies (e.g., hyper/hypolordosis, hyper/hypokyphosis) and mobility deficits (e.g., bending restrictions) have been of interest to researchers and clinicians. Machine-based isolated lumbar extension resistance exercise (ILEX) has been used successfully for rehabilitation of patients suffering from low back pain. The aim of this study was to analyse the immediate effects of ILEX on spinal posture and mobility. In this interventional cohort study, the posture and mobility measures of 33 healthy individuals (m = 17, f = 16; mean age 30.0 years) were taken using the surface-based Spinal Mouse system (IDIAG M360©, Fehraltdorf, Switzerland). Individuals performed one exercise set to full exhaustion with an ILEX-device (Powerspine, Wuerzburg, Germany) in a standardized setup, including uniform range of motion and time under tension. Scans were made immediately before and after the exercise. There was an immediate significant decrease in standing lumbar lordosis and thoracic kyphosis. No change could be observed in standing pelvic tilt. Mobility measures showed a significant decrease in the lumbar spine and an increase in the sacrum. The results show that ILEX alters spine posture and mobility in the short-term, which may benefit certain patient groups.

Prevalence of Lumbosacral Transitional Vertebral Anomalies Among Healthy Volunteers and Patients with Hip Pathology: Association with Spinopelvic Characteristics.

This cross-sectional study included 102 patients with hip pathology and 51 asymptomatic volunteers (mean age, 33.9 ± 7.3 years; mean body mass index, 26.0 ± 5.0 kg/m2; 57.5% female). Participants underwent radiographic assessment of the lumbar spine and pelvis in standing and deep-seated positions. LSTV occurrence was classified according to the Castellvi system. Spinopelvic characteristics included lumbar lordosis (including segmental lumbar angles), pelvic tilt, and hip flexion (pelvic-femoral angle). Differences between standing and deep-seated values were calculated. Low back pain was assessed using the Oswestry Disability Index. The prevalence of LSTV type ≥II was 8.5%, with no difference between patients and volunteers (p = 0.386). Individuals with an LSTV had a greater standing L1-L5 angle (mean, 51.6° ± 11.7° versus 38.9° ± 9.3°; p < 0.001). The overall spinal flexion (change in L1-S1 angle between the standing and deep-seated positions) in individuals with an LSTV was similar to that in individuals without an LSTV; restricted L5-S1 mobility was compensated for at L1-L2 (10.2° ± 5.8° in those with versus 8.4° ± 4.1° in those without an LSTV; p = 0.070). No significant difference in the presence of low back pain was found (p = 0.250). An LSTV was found in 8.5% of young adults, with no difference between patients with hip pathology and controls. Individuals with an LSTV have greater standing lumbar lordosis, with altered mechanics at the cephalad adjacent level, which may predispose these individuals to degenerative changes at this level. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Relation significative entre l’incidence pelvienne et la lordose lombaire debout, et la flexibilité lombaire chez les patients japonais atteints d’arthrose de la hanche : une étude radiographique descriptive

IntroductionSpine stiffness is known to increase the risk of total hip replacement (THR) instability. The sagittal posture and lumbo-pelvic kinematics have therefore become parameters of interest when planning THR. We conducted this study to investigate (1) the distribution and characteristics of the spino-pelvic standing alignment, (2) the relationship between pelvic incidence (PI) and standing lumbar lordosis (LL) and lumbar flexibility, in Japanese hip osteoarthritis patients. Hypothesis(1) Japanese hip osteoarthritis patients with different sagittal spino-pelvic alignments do not differ markedly in their demographics, PI, or lumbar flexibility; and (2) there is no significant relationship between PI, standing LL, and lumbar flexibility in a population of Japanese hip osteoarthritis patients. Material and methodsA retrospective study of radiographs from 945 Japanese patients who consecutively received THR for the treatment of hip osteoarthritis. All patients preoperatively underwent lateral standing and deep-seated lumbo-pelvic radiography on which the spino-pelvic parameters were measured. The difference between the standing and deep-seated LL angles defined the lumbar flexibility and was calculated as the delta (Δ) LL. Individual spino-pelvic standing alignment was stratified based on the difference between the PI and standing LL (‘PI-LL mismatch’). ‘PI-LL mismatch’ of<−10°, between −10° and 10°, and>10° was defined as hyperlordosis, normolordosis, and flatback, respectively. ResultsIn the present study, the spinal alignment of 115/945 (12.2%), 559/945 (59.2%), and 271/945 (28.6%) patients were classified as hyperlordosis, normolordosis, and flatback, respectively. Hyperlordotic patients had significantly lower PI (47.6°±7.8° vs. 52.7°±10.5°, p<0.001) and higher ΔLL (60.6°±12.6° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. Patients with flatback were significantly older (age, 69.1±9.1years vs. 62.7±9.8years, p<0.001) with higher PI (56.9°±11.7° vs. 52.7°±10.5°, p<0.001) and lower ΔLL (35.2°±17.4° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. A significant relationship between PI and the standing LL was found in the whole cohort (r=0.409, p=0.009), hyperlordotic (r=0.785, p<0.001), normolordotic (r=0.857, p<0.001), and flatback (r=0.664, p<0.001) patients. Significant relationships between the PI and ΔLL were also found in normolordotic (r=0.442, p=0.004) and flatback (r=0.449, p=0.003) patients but not hyperlordotic patients (r=0.154, p=0.367). DiscussionA large proportion of Japanese hip osteoarthritis patients have abnormal PI-LL mismatch (12% and 29% have hyperlordosis and flatback, respectively). The PI was a determinant of the standing LL, and the standing LL was a strong determinant of the lumbar flexibility, especially in the normolordotic and hyperlordotic individuals. Level of evidenceIII; retrospective diagnostic radiographic study.

The significant relationship among the factors of pelvic incidence, standing lumbar lordosis, and lumbar flexibility in Japanese patients with hip osteoarthritis: A descriptive radiographic study

IntroductionSpine stiffness is known to increase the risk of total hip replacement (THR) instability. The sagittal posture and lumbo-pelvic kinematics have therefore become parameters of interest when planning THR. We conducted this study to investigate (1) the distribution and characteristics of the spino-pelvic standing alignment, (2) the relationship between pelvic incidence (PI) and standing lumbar lordosis (LL) and lumbar flexibility, in Japanese hip osteoarthritis patients. Hypothesis(1) Japanese hip osteoarthritis patients with different sagittal spino-pelvic alignments do not differ markedly in their demographics, PI, or lumbar flexibility; and (2) there is no significant relationship between PI, standing LL, and lumbar flexibility in a population of Japanese hip osteoarthritis patients. Material and MethodsA retrospective study of radiographs from 945 Japanese patients who consecutively received THR for the treatment of hip osteoarthritis. All patients pre-operatively underwent lateral standing and deep-seated lumbo-pelvic radiography on which the spino-pelvic parameters were measured. The difference between the standing and deep-seated LL angles defined the lumbar flexibility and was calculated as the delta (Δ) LL. Individual spino-pelvic standing alignment was stratified based on the difference between the PI and standing LL (‘PI-LL mismatch’). ‘PI-LL mismatch’ of<−10°, between −10° and 10°, and>10° was defined as hyperlordosis, normolordosis, and flatback, respectively. ResultsIn the present study, the spinal alignment of 115/945 (12.2%), 559/945 (59.2%), and 271/945 (28.6%) patients were classified as hyperlordosis, normolordosis, and flatback, respectively. Hyperlordotic patients had significantly lower PI (47.6°±7.8° vs. 52.7°±10.5°, p<0.001) and higher ΔLL (60.6°±12.6° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. Patients with flatback were significantly older (age, 69.1±9.1 years vs. 62.7±9.8 years, p<0.001) with higher PI (56.9°±11.7° vs. 52.7°±10.5°, p<0.001) and lower ΔLL (35.2°±17.4° vs. 51.6°±12.8°, p<0.001) than normolordotic patients. A significant relationship between PI and the standing LL was found in the whole cohort (r=0.409, p=0.009), hyperlordotic (r=0.785, p<0.001), normolordotic (r=0.857, p<0.001), and flatback (r=0.664, p<0.001) patients. Significant relationships between the PI and ΔLL were also found in normolordotic (r=0.442, p=0.004) and flatback (r=0.449, p=0.003) patients but not hyperlordotic patients (r=0.154, p=0.367). DiscussionA large proportion of Japanese hip osteoarthritis patients have abnormal PI-LL mismatch (12% and 29% have hyperlordosis and flatback, respectively). The PI was a determinant of the standing LL and the lumbar flexibility, especially in the normolordotic and flatback individuals. Level of EvidenceIII; retrospective diagnostic radiographic study.

Moving Toward Individual-Specific Automotive Seat Design: How Individual Characteristics and Time Alter the Selected Lumbar Support Prominence.

To explore how individual characteristics influence selected lumbar support prominence (LSP), seated lumbar flexion, seatback average pressure, contact area, and center of pressure (CoP) location before and after 1 hr of driving. An LSP can alter posture and may reduce low back pain during prolonged driving. Although LSP preference varies across individuals and may change over time, few investigations have explored the time-varying response to individually selected adjustable seat parameters. Forty individuals selected LSP settings in an automotive seat through a series of systematic adjustment trials. The average LSP setting was fixed for a 1-hr driving simulation, followed by one final adjustment trial. Regressions were performed between individual characteristics and selected LSP, lumbar posture, and measures of seatback pressure from the initial adjustment trials. ANOVAs were performed to determine the effect of time and sex on these dependent variables. Discomfort was also monitored throughout the protocol. Individual's standing lumbar lordosis, selected LSP, and height and mass were significant predictors for seated lumbar flexion, seatback average pressure, and contact area, respectively. Discomfort levels remained low; however, following the driving protocol, individuals altered their posture to decrease lumbar flexion and increase seatback average pressure without significant adjustments to the LSP. These findings highlight individual characteristics to consider in automotive seat design and that the method for determining LSP settings may facilitate appropriate LSP selection. A systematic method to determine LSP settings may reduce discomfort and automate seat adjustments, such that only short-term postural adjustments may be required.

Does timing of lumbar fusion affect dislocation rate after total hip arthroplasty?

IntroductionThe impact of lumbar spinal fusion (LSF) on pelvic mobility and increased risk for THA dislocation are recognized. However, there is still controversy on whether THA should be performed prior or following LSF. This study aims to compare the rates of hip dislocation in patients undergoing THA prior to or following LSF. MethodsWe retrospectively reviewed 109 primary THA and LSF. There were 34 men and 75 women with a mean age of 66.9. The cohort was divided into 2 groups: 1) THA prior to lumbar fusion (n = 42) and 2) THA following lumbar fusion (n = 67). Radiographic parameters including acetabular component abduction, anteversion, pelvic incidence (PI), sacral slope, standing lumbar lordosis (LL) and PI-LL mismatch were determined for each patient. The surgical approach and THA parameters were also recorded and compared between the 2 groups. Patients with fracture, malignant disease, and prior hip hardware were excluded. ResultsThe mean follow up was 14.7 months. Overall, 8 patients (7.3%) had a postoperative hip dislocation (0 in group 1 (0%), and 8 in group 2 (11.9%) (p = 0.022). The mean cup abduction and anteversion in patients that dislocated was 37.7° and 23.4° respectively while patients who did not dislocate had an average cup abduction of 37.6° (p = 0.970) and anteversion of 25.9° (p = 0.367). Patients who dislocated had decreased lumbar lordosis (p = 0.022) and higher PI-LL mismatch (p = 0.0004) compared to that did not dislocate. There were no other significant differences in the spinopelvic parameters between the 2 groups. Neither surgical approach nor dual mobility articulations use had a significant impact on postoperative dislocations. ConclusionHigher rates of hip dislocation were observed in patients undergoing primary THA following LSF. Dislocators had decreased lumbar lordosis and increased PI-LL mismatch. Patients who require both spinal fusion and THA should undergo hip arthroplasty first to minimize the risk of postoperative instability.

The relationship between pelvic incidence and anatomical acetabular anteversion in female Japanese patients with hip osteoarthritis: a retrospective iconographic study.

This study aimed (1) to investigate the relationship between pelvic incidence (PI) and the anatomical acetabular anteversion (AA) relative to the spino-pelvic tilt (SPT) plane (anatomical AASPT), relative to the anterior pelvic plane (anatomical AAAPP), and functional standing AA; and (2) to compare AA and the sagittal spino-pelvic parameters of lumbo-pelvic complex types 1 (PI ≤ 30°) and 2 (PI > 30°), in Japanese females with hip osteoarthritis. We conducted a retrospective study on 110 Japanese females with unilateral hip osteoarthritis. PI, standing lumbar lordosis (LL), standing SPT, anatomical AASPT, anatomical AAAPP, and functional standing AA were measured and calculated using radiographs and computed tomography. The PI-LL difference was defined as the mathematical difference between the PI and standing LL angles. Pearson's correlation test was used to measure the relationship between the PI and AA. Student's t test was used to compare spino-pelvic parameters between lumbo-pelvic complex type 1 (n = 24) and type 2 (n = 86). There was a significant relationship between the PI and anatomical AASPT (r = -0.532, p < 0.001), but no significant relationship between the PI and anatomical AAAPP (r = -0.021, p = 0.824) or functional standing AA (r = 0.104, p = 0.299). Lumbo-pelvic complex type 1 had a higher anatomical AASPT (22.4° ± 9.1° vs. 5.4° ± 15.1°, p < 0.001), similar anatomical AAAPP (15.0° ± 10.6° vs. 15.1° ± 15.3°, p = 0.981) and functional standing AA (12.4° ± 8.0° vs. 15.0° ± 14.1°, p = 0.254), a lower standing SPT (- 14.3° ± 11.0° vs. 13.7° ± 12.6°, p < 0.001), and a lower PI-LL difference (- 14.4° ± 18.5° vs. 6.4° ± 17.1°, p < 0.001) in comparison to lumbo-pelvic complex type 2. Our findings will help to improve the understanding of hip anatomy and its relationship with the standing spino-pelvic alignment in Japanese females with hip osteoarthritis.

Preoperative factors improving the prediction of the postoperative sagittal orientation of the pelvis in standing position after total hip arthroplasty

The aims of this study were to investigate if the sagittal orientation of the pelvis (SOP) in the standing position changes after total hip arthroplasty (THA) and evaluate what preoperative factors may improve the prediction of the postoperative standing SOP in the context of a patient-specific functional cup orientation. 196 primary THA patients from Japan were retrospectively selected for this study. Computed tomography imaging of the pelvis, EOS imaging of the lower body and lateral radiographs of the lumbar spine in the standing position were taken preoperatively. Common biometrics and preoperative Harris Hip Score were recorded. The EOS imaging in the standing position was repeated three months following THA. A 3D/2.5D registration process was used to determine the standing SOP. Thirty-three preoperative biometric, morphological and functional parameters were measured. Important preoperative parameters were identified that significantly improve the prediction of the postoperative standing SOP by using multiple linear LASSO regression. On average, the SOP changed significantly (p < 0.001) between the preoperative and postoperative standing position three months after THA by 3° ± 4° in the posterior direction. The age, standing lumbar lordosis angle (LLA) and preoperative supine and standing SOP significantly (p < 0.001) improve the prediction of the postoperative standing SOP. The linear regression model for the prediction of the postoperative standing SOP is significantly (p < 0.001) improved by adding the parameters preoperative standing SOP and LLA, in addition to the preoperative supine SOP, reducing the root mean square error derived from a leave-one-out cross-validation by more than 1°. The mean standing SOP in Japanese patients changes already three months after THA in comparison to the preoperative value. The preoperative factors age, LLA, supine and standing SOP can significantly improve the prediction of the postoperative standing SOP and should be considered within the preoperative planning process of a patient-specific functional cup orientation.

Wednesday, September 26, 2018 3:35 PM – 5:05 PM Preserving Spinal Motion: 92. A prospective, multicenter evaluation of the relationship between standing and recumbent surgical lumbar lordosis

BACKGROUND CONTEXT Lumbosacral and global spinal alignment are increasingly understood to affect health-related quality of life and long-term survivability of spinal fusion procedures. As alignment considerations in surgical decision-making continue to become more common, a reliable understanding of standing versus recumbent alignment may aid in reconciling preoperative alignment planning with intraoperative surgical decision-making. PURPOSE The purpose of this study was to compare standing lumbar lordosis with intraoperative recumbent lordosis on a variety of tables and in a variety of surgical positions. STUDY DESIGN/SETTING A prospective, multi-center, evaluation of standing to recumbent spinopelvic alignment was performed at 15 US institutions. PATIENT SAMPLE A total of 414 patients were enrolled. Patients were eligible for inclusion if they were at least 18 years of age and were undergoing spine surgery of any kind, at any number of levels between T1 and the pelvis, and who had preoperative lateral radiographs inclusive of the femoral head axis. Mean age of the patients was 61 years and 53% of patients were female. OUTCOME MEASURES Position of the patient during surgery, surgical table style used, and the use of additional positioning methods were collected and used as grouping variables in factorial analysis of variance (ANOVA) tests. METHODS Preoperative alignment measurements were made using NuVaMap (NuVasive, Inc. San Diego, CA, USA) software while intraoperative evaluations were made using NuVaMap O.R. (NuVasive, Inc.). Measurements included lumbar lordosis (LL) before and during surgery. RESULTS The lateral decubitus position was used in 170 (41%) cases, prone in 203 (49%), and supine in 41 (10%) cases. A Wilson frame was used in 55 (14%) cases while a spinal table (ie, Jackson) and common surgical bed were used in 37% (150) and 49% (196) of cases, respectively. Average standing preoperative lordosis for all patients was 48.6° which was maintained intraoperatively to 47.9° (p=.472). When examining only the table used, patients placed in Wilson frames lost an average of 10.7° of LL compared to standing, with common surgical beds and spinal tables losing 0.0° and gaining 2.4°, respectively (p CONCLUSIONS These data show that, on average, the difference between standing and intraoperative, recumbent, positioned lumbar lordosis in patients undergoing spine surgery is negligible (48.6° vs. 47.9°, respectively). Prone position on a Wilson frame, intuitively, resulted in the greatest loss of lordosis (10.7°) compared to standing, with supine position on a common surgical or Jackson table resulting in the most gained lordosis (5.7° and 4.9°, respectively). Large alignment variance seen in this study also suggests that intraoperative alignment assessment has utility in individualizing patient care based on real-time feedback. Future work will assess the relationship between preoperative standing, intraoperative recumbent, and postoperative standing alignment. From this work, since enrollment included patients undergoing any spinal procedure, not necessarily just fusions, it should not be assumed that these results correlate directly to postoperative alignment (eg, where lumbar flexion might be desired in decompressive procedures). FDA DEVICE/DRUG STATUS NuvaMap (Approved for this indication), NuvaMap OR (Approved for this indication)

Characterisation of the correlation between standing lordosis and degenerative joint disease in the lower lumbar spine in women and men: a radiographic study

BackgroundDegenerative joint disease (DJD) in the lumbar spine is a common condition that is associated with chronic low back pain. Excessive loading of lumbar joints is a risk factor for DJD. Changes in lumbar lordosis significantly redistribute the forces of weight-bearing on the facet joints and the intervertebral discs. However, the relationship between lumbar lordosis and DJD has not been characterized in men and women.MethodsWe characterised the correlation between standing lumbar lordosis and DJD in standing radiographic images from 301 adult female and male chiropractic patients. DJD was rated using the Kellgren-Lawrence scale, and lordosis was measured using the Cobb angle. Linear and curvilinear correlations were investigated while controlling for age and sex.ResultsWe found a highly significant curvilinear correlation between lordosis and DJD of the lower lumbar spine in both sexes, but especially in women, irrespective of the effects of age. We found the effect size of lordosis on lower lumbar DJD to be between 17.4 and 18.1% in women and 12.9% in older men. In addition, lordosis of 65 (95% CI 55.3–77.7) and 68 (98% CI 58.7–73.3) degrees were associated with minimal DJD in the lower lumbar spine of women and men respectively, and were therefore considered ‘optimal’. This optimal lordotic angle was 73 (95% CI 58.8–87.2) degrees in older men.ConclusionsBoth hypo- and hyper-lordosis correlate with DJD in the lumbar spine, particularly in women and in older men. These findings may well be of relevance to spinal pain management and spinal rehabilitation.

Preoperative, Intraoperative, and Postoperative Standing Lordosis After Pedicle Subtraction Osteotomy: An Analysis of Radiographic Parameters and Surgical Strategy

Study DesignRetrospective consecutive case series. ObjectivesThe objective of this study was to investigate the relationship between intraoperative and postoperative lumbar spine measurements after pedicle subtraction osteotomy (PSO). We analyzed the amount of lordosis lost between the prone intraoperative image and the final upright standing film. The outcome of this analysis should be used in preoperative planning for osteotomy procedures. MethodsSixteen patients had pre-, intra- and postoperative measurements of lumbar lordosis. Pre- and postoperative measures of pelvic parameters were also determined. Comparisons were made between pre-, intra- and postoperative measures of pelvic parameters, with specific attention to lumbar lordosis correction and the loss of correction with transition to a standing position. ResultsThe average pelvic mismatch between preoperative lumbar lordosis and pelvic incidence was 37 degrees whereas the postoperative mismatch measured 3.2 degrees. All patients had a significant correction of their lumbar lordosis. The lumbar lordosis showed a highly significant loss of 12.5 degrees from the intraoperative prone position to the postoperative standing position, with the average lumbar lordosis intraoperatively (67 degrees) decreasing to a standing lumbar lordosis of 54 degrees (p < .000001). ConclusionsThis analysis should aid in preoperative planning for sagittal global alignment correction and can reduce the chance of over- or under-correction in patients having a PSO procedure. Given the narrow postoperative target that is associated with better outcomes for patients, the loss of lumbar lordosis from prone to standing position may be a crucial variable in this planning process.

Comparison between Standing and Supine Lateral Radiographs in Low Grade Spondylolisthesis

To analyze the differences between standing and supine plain film lateral radiographs of the lumbosacral region in low grade (grade I/II) spondylolisthesis using the Picture Archiving and Communication System (PACS) software. Demonstrable difference might be a parameter of instability which might be useful in planning surgical treatment when it is too painful for patients to undergo flexion/extension Xrays.Radiographs of 23 patients with low grade spondylolisthesis were analyzed for percentage slip, lumbar lordosis, disc height, sacral inclination and slip angle. These standing and supine lateral radiographs were taken at the same distance with the same magnification. Measurements obtained were statistically analyzed with the SPSS software using the student t test for statistical significance (p&lt;0.05).A significant difference (p &lt; 0.05) was found between the standing percentage slip (mean 36.85% ± 12.78%) and supine percentage slip (mean 27.39% ± 11.14%) (p = 0.01). Similarly, standing lumbar lordosis (mean 37.74% ± 10.96%) and supine lumbar lordosis (mean 30.96% ± 12.76%) revealed a marginally higher p value (p =0.06). However, differences in the disc space height (p=0.09), sacral inclination (p=1) and slip angle (p=0.55) did not show any statistical significance. The standing radiographs effectively demonstrate the increase in slip percentage. This can have a significant impact on the grading of slip which can influence the treatment strategy. Also the increase of slip values on standing Xrays adds a parameter of instability which might be considered in the management strategy.DOI: http://dx.doi.org/10.3126/jmmihs.v1i4.11996Journal of Manmohan Memorial Institute of Health SciencesVol. 1, Issue 4, 2015Page: 14-18

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.

The effect of interspinous implant surgery on back surface shape and radiographic lumbar curvature

Background Interspinous process implants, used to augment lumbar spine surgery, putatively induce a local segmental lumbar kyphosis yet few investigations outline the effect in vivo on thoracolumbar sagittal curvature. Changes in lumbar skeletal alignment and posture have traditionally relied upon radiographic and back surface spinal curvature measurements, respectively. Methods Lumbar lordosis curvature in 10 healthy subjects (6F, 4M; mean age 36 years) and 10 interspinous implant lumbar surgery patients (5F, 5M; mean age 51 years) was assessed with rasterstereography at baseline and at 6 weeks. Skeletal lumbar lordosis in standing was measured from lateral erect radiography pre- and 6 weeks post-operatively in the surgical cohort, and compared to angulation obtained for surface lordosis curvature derived from rasterstereography. Findings Repeatable measurement of standing lumbar lordosis from rasterstereographic back shape imaging in healthy volunteers and lumbar surgery cases was demonstrated. Reductions of 0.6 (NS) in healthy and 3.1 (significant, P < 0.001) in surgical subjects were recorded for surface lumbar lordosis angle between the 6 week time-points. Slight flattening of the segmental angle and regional lordosis after DIAM surgery was revealed by radiography. Skeletal and surface lumbar lordosis changes were uncorrelated preoperatively ( ρ = 0.28) and postoperatively ( ρ = 0.26). Interpretation Rasterstereography is sensitive in assessing lumbar lordosis changes in healthy and lumbar surgical individuals over time. Surgery with DIAM for lumbar pathology may result in an initial mild flattening of lordosis. Serial investigations of spinal curvature after surgery with DIAM interspinous implant are warranted in order to better understand the time-course of spinal posture changes of such cases.

The Clinical Characteristics and Risk Factors for the Adjacent Segment Degeneration in Instrumented Lumbar Fusion

A retrospective study. The aims of this study were to evaluate the clinical significance of, characteristics of, and risk factors for adjacent segment degeneration (ASD) in patients who have undergone instrumented lumbar fusion. ASD has been considered a potential long-term complication of spinal arthrodesis. However, the exact mechanisms and risk factors related to ASD are not completely understood. A total of 48 patients who underwent instrumented lumbar fusion at L4-5 and had minimal ASD preoperatively were evaluated. The patients were divided into 2 groups at follow-up according to the development of ASD defined by radiologic criteria. Through review of their medical records and the radiologic files, the following variables were evaluated in the 2 groups: basic demographic data, body weight, body height, body mass index, bone mineral density, types of surgical approaches, preoperative and postoperative segmental and lumbar lordosis, and clinical outcomes. ASD was found in 30 (62.5%) patients. The variables that showed statistical intergroup differences were the mean age at surgery, the mean difference in the degree of preoperative from postoperative lumbar lordosis, and the proportion of patients who underwent anterior lumbar interbody fusion. However, there were no statistically significant intergroup differences in the Japanese Orthopedic Association score at 1-year postoperatively or at the final follow-up, or in the recovery rate, success rate, and complication rate. Radiographic ASD is relatively common long-term finding associated with instrumented lumbar fusion. However, radiographic evidence of ASD does not necessarily correlate with a poor outcome. Our results suggest that advanced age, anterior lumbar interbody fusion, and the restoration of the preoperative standing lumbar lordosis may have a protective effect against the development of ASD.