Influence of spine morphology on intervertebral disc loads and stresses in asymptomatic adults: implications for the ideal spine

The Association of Sagittal Spinal Posture among Elementary School Pupils with Sex and Grade

The objective of this research was to analyze and elucidate the sagittal spinal posture status in older elementary school children, considering their gender and grade differences. The study involved 484 school children (252 males and 232 females) from grades V to VIII, assessed for sagittal spinal posture using the Formetric 4D System. The analysis, employing the Chi-squared test of independence along with the Z-test, did not reveal significant grade-related differences (p < 0.52) in the incidence of normal sagittal alignment or diagnosed outliers. However, within grade levels, no significant difference was observed for male participants (p < 0.80), while a significant difference was identified for females (p < 0.01). Examining gender differences across grades, a disparity was noted only among seventh graders concerning normal spine alignment and outlier existence (p < 0.01), favoring male participants. Regardless of the grade, a significant gender difference emerged in the location of diagnosed outliers: kyphosis (M = 108 vs. F = 72), lordosis (M = 5 vs. F = 14), kypholordosis (M = 18 vs. F = 66), and flatback outlier of the lumbar spine (M = 27 vs. F = 11). These findings suggest potential adjustments to the curriculum and highlight the need to tailor physical education instruction based on this study's outcomes. Consequently, these results imply the importance of a differentiated approach in preventing sagittal plane outliers of the spine in adolescent children.

Orthopedic mechanism analysis of growing rod distraction for early-onset scoliosis based on 3D morphological parameters

Traditional growing rod (TGR) provides a corrective moment for deformed segments to straighten the spine, whose clinical efficacy has proven positive and growth-friendly. However, an insufficient understanding of orthopedic mechanisms can affect the development of clinical strategies. This research attempts to analyze the spine that has undergone four distraction operations: exploring the spinal orthopedic mechanism, including alignment, growth, and morphology. In this study, the spinal morphology curves were illustrated in three human planes to exhibit the changes in spinal alignment. The spinal growth characteristics were measured to discuss the unsynchronized and diminishing growth rate. The spinal deformations were evaluated to indicate asymmetric growth. As a result, the spinal alignment changes indicated the orthopedic process improved, but the re-unbalance occurred after multiple distractions. Then, unsynchronized growth existed in the superior and inferior segments, and the growth rate over every distraction diminished. Finally, asymmetric growth was indicated as the axial/circumferential growth ratio getting greater and the cuneate level approaching normal. Accordingly, a TGR is growth-friendly, but combining the osteotomy fusion of lumbar segments for severe early-onset scoliosis may be an excellent choice to solve the insufficient corrective stimulation. Regarding the distraction process, reshaping before the final fusion can fix the balance loss, and a prolonged distraction frequency fits the law of diminishing return. In conclusion, studying orthopedic mechanisms based on morphological measurement can guide clinical strategy optimization.

Assessment of the stiffness of the upper trapezius muscle in a group of asymptomatic people with cervical spine rotation asymmetry

This study investigated the relationship between the stiffness of the upper trapezius muscle and the range of rotational movement of the cervical spine. A total of 60 right-handed asymptomatic students participated in the study. Participants (N = 22) characterised by asymmetry in rotational movements were selected for the experimental group. A difference of ≥10° between right and left rotation of the cervical spine was considered asymmetrical. The control group (N = 38) included participants whose rotation difference was < 10°. Belonging to the experimental or control group did not significantly differentiate trapezius muscle stiffness. The rotation side differentiated the stiffness of the right and left trapezius muscles only in the group of people with rotational movement asymmetry. There were high correlation coefficients between right cervical rotation and the stiffness of the muscle on the right side, and between rotation to the left and the stiffness of the muscle on the left side. There is a relationship between the stiffness of the right and left upper trapezius muscles and the range of right and left rotational motion of the cervical spine. Stiffness of the upper trapezius correlates more strongly with rotation to the side on which the muscle lies than to the opposite side. Increased stiffness of the upper trapezius muscle on the side of limited cervical spine rotation is likely to be determined by the muscle fibre stretching mechanism.

Male spondyloarthritis patients and those with longer disease duration have less severe disc degeneration: propensity score-matched comparison

Objective

Using whole spine sagittal T2 MRI, we aimed to compare the severity and prevalence of disc degeneration (DD) in axial SpA patients vs the general population and to determine any association between spinal inflammation, structural changes, mobility and DD among SpA patients.

Methods

Two prospectively collected cohorts of SpA patients (n = 411) and the general population (n = 2007) were recruited. Eventually, 967 participants from the populational cohort and 304 participants from the SpA cohort were analysed. Two hundred and nineteen matched pairs were generated by propensity score matching. Imaging parameters, including Pfirrmann grading, disc herniation, high-intensity zone, Schmorl's node, Modic change and anterior marrow change were studied and compared from C2/3 to L5/S1. DD was defined as Pfirrmann grade 4 or 5. Demographic factors, including age, sex and BMI, were collected. Multivariable linear regression was used to determine the association between spinal inflammation [Spondyloarthritis Research Consortium of Canada (SPARCC) spine MRI index], structural changes [modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS)] and mobility (BASMI) with lumbar Pfirrmann score.

Results

SpA patients had lower prevalence of DD (P < 0.001). The disease stage-stratified regression model showed that SPARCC spinal MRI index was associated with higher lumbar Pfirrmann scores in early disease (β = 0.196, P = 0.044), whereas mSASSS was associated with lower lumbar Pfirrmann scores in later disease (β = -0.138, P = 0.038). Males had higher mSASSS (P < 0.001) and lower odds of whole spine DD (odds ratio = 0.622, P = 0.028).

Conclusion

SpA patients had lower DD severity than the general population. Males had higher mSASSSs, and increased mSASSS at later disease was associated with less severe DD.

L4/5 Disc Herniation: Not Unusually Accompanied with L5/S1 Low-Grade Spondylolytic Spondylolisthesis

OBJECTIVE

Isthmic spondylolisthesis (IS) is distinguished by a congenital defect or acquired fracture of the pars interarticularis. Numerous studies on L5 low-grade IS have been carried out; however, there is a paucity of data regarding the condition of L5 IS concomitant with L4/5 disc herniation. This study aimed to identify the incidence rate and to illustrate the possible risk factors for L4/5 disc herniation in L5 low-grade IS patients.

METHODS

A total of 268 consecutive patients diagnosed as L5/S1 low-grade IS between May 2017 and May 2022 were retrospectively enrolled in this study. Depending on the presence of L4/5 disc herniation or not, patients were divided into an L4/5 disc herniation group (L4/5 DH) and an L4/5 non-disc herniation group (L4/5 non-DH). Radiographic parameters were measured, and the ratios of L4-S1 segmental lordosis (SL) to lumbar lordosis (LDI), L4 inferior endplate (IEP) to L5 superior endplate (SEP) (L4 IEP/L5 SEP), and L5 IEP to S1 SEP (L5 IEP/S1 SEP) were compared between groups. The Pfirrmann grade of the L4/5 disc and the L5/S1 disc, and Roussouly classifications of each patient were also recorded. Univariate analysis (including independent-samples t-test and χ2 -test) and multiple logistic regression analysis were performed to analyze the data.

RESULTS

There were 40 patients (14.9%) in the L4/5 DH group. The Roussouly classification differed significantly between groups. As demonstrated by the Pfirrmann grade, the L4/5 DH group showed more advanced disc degeneration at L4/5 than the L4/5 non-DH group. In contrast to the L4/5 non-DH group, the L4/5 DH group had a significantly larger L4 IEP, L4 IEP/L5 SEP, S1 SEP, and LDI while smaller L4/5 disc angle, L4/5 disc height, slip percentage, lumbar lordosis, and sacral slope. Multivariate logistic regression analysis revealed that higher L4/5 disc Pfirrmann grade (p = 0.004), decreased L4/5 disc height (p < 0.001), and lower L5 slip percentage (p = 0.022) were significantly associated with the occurrence of L4/5 DH.

CONCLUSIONS

L4/5 disc herniation is not unusually accompanied by L5/S1 low-grade IS. Advanced L4/5 disc degeneration, decreased L4/5 disc height, and lower L5 slip percentage might be significantly associated with L4/5 disc herniation.

Personalized assessment and management of non-specific low back pain

BACKGROUND AND OBJECTIVE

Low back pain (LBP), and in particular non-specific low back pain (NSLBP), which accounts for approximately 90% of LBP, is the leading cause of years lived with disability worldwide. In clinical trials, LBP is often poorly categorized into 'specific' versus 'non-specific' and 'acute' versus 'chronic' pain. However, a better understanding of the underlying pain mechanisms might improve study results and reduce the number of NSLBP patients.

DATABASES AND DATA TREATMENT

Narrative review.

RESULTS

NSLBP is a multi-dimensional, biopsychosocial condition that requires all contributing dimensions to be assessed and prioritized. Thereby, the assessment of the contribution of nociceptive, neuropathic and nociplastic pain mechanisms forms the basis for personalized management. In addition, psychosocial (e.g. anxiety, catastrophizing) and contextual factors (e.g. work situation) as well as comorbidities need to be assessed and individually weighted. Personalized treatment of NSLBP further requires individually choosing treatment modalities, for example, exercising, patient education, cognitive-behavioural advice, pharmacotherapy, as well as tailoring treatment within these modalities, for example, the delivery of tailored psychological interventions or exercise programs. As the main pain mechanism and psychosocial factors may vary over time, re-assessment is necessary and treatment success should ideally be assessed quantitatively and qualitatively.

CONCLUSIONS

The identification of the main contributing pain mechanism and the integration of the patients' view on their condition, including beliefs, preferences, concerns and expectations, are key in the personalized clinical management of NSLBP. In research, particular importance should be placed on accurate characterization of patients and on including outcomes relevant to the individual patient.

SIGNIFICANCE STATEMENT

Here, a comprehensive review of the challenges associated with the diagnostic label 'non-specific low back pain' is given. It outlines what is lacking in current treatment guidelines and it is summarized what is currently known with respect to individual phenotyping. It becomes clear that more research on clinically meaningful subgroups is needed to best tailor treatment approaches.

Failed back surgery syndrome successfully ameliorated with Chiropractic Biophysics® structural rehabilitation improving pain, disability as well as sagittal and coronal balance: a Chiropractic Biophysics® case report with a 6 year follow-up

[Purpose] To present the case of the amelioration of chronic pain and disability in a patient suffering from failed back surgery syndrome. [Participant and Methods] A 27-year-old male with chronic low back pain was treated with a Coflex® intra-spinous instrument, however, it was removed shortly after due to poor outcome including worsening pain and disability. Radiographic assessment revealed significant posterior translation of the thorax complicated by significant loss of the normal lumbar lordosis and a left lateral translated thoracic cage posture. Chiropractic Biophysics® technique was applied over a 5.5-month period leading to structural spine improvements as well as improved pain, Oswestry disability index (ODI) and quality of life (QOL). [Results] There was a 21 mm reduction in posterior thoracic translation, a 6.2° improvement in lumbar lordosis and a 16 mm reduction in lateral thoracic translation corresponding with improved ODI and QOL scores. A 6 year follow-up showed successful outcome despite some degenerative changes in the spine at the prior surgical level. [Conclusion] This case adds to the growing literature showing the efficacy of non-surgical spinal rehabilitative methods in improving outcomes in patients with spinal deformity and associated disabilities. This case also demonstrates necessity of the continued criterion standard of spinal radiography for biomechanical assessment.

Prevalence and distribution of Schmorl node and endplate signal change, and correlation with disc degeneration in a population-based cohort: the Wakayama Spine Study

PURPOSE

Degenerative spinal conditions, including disc degeneration (DD), Schmorl nodes (SN), and endplate signal changes (ESC), are pervasive age-associated phenomena that critically affect spinal health. Despite their prevalence, a comprehensive exploration of their distribution and correlations is lacking. This study examined the prevalence, distribution, and correlation of DD, SN, and ESC across the entire spine in a population-based cohort.

METHODS

The Wakayama Spine Study included 975 participants (324 men, mean age 67.2 years; 651 women, mean age 66.0 years). Magnetic resonance imaging (MRI) was used to evaluate the intervertebral space from C2/3 to L5/S1. DD was classified using Pfirrmann's system, ESC was identified by diffuse high-intensity signal changes on the endplates, and SN was defined as a herniation pit with a hypointense signal. We assessed the prevalence and distribution of SN, ESC, and DD across the entire spine. The correlations among these factors were examined.

RESULTS

Prevalence of ≥ 1 SN over the entire spine was 71% in men and 77% in women, while prevalence of ≥ 1 ESC was 57.9% in men and 56.3% in women. The prevalence of ESC and SN in the thoracic region was the highest among the three regions in both sexes. Positive linear correlations were observed between the number of SN and DD (r = 0.41, p < 0.001) and the number of ESC and DD (r = 0.40, p < 0.001), but weak correlations were found between the number of SN and ESC (r = 0.29, p < 0.001).

CONCLUSION

The prevalence and distribution of SN and ESC over the entire spine were observed, and correlations between SN, ESC, and DD were established. This population-based cohort study provides a comprehensive analysis of these factors.

Why Are Some Intervertebral Discs More Prone to Degeneration?: Insights Into Isolated Thoracic "Dysgeneration"

STUDY DESIGN

Prospective observational study.

OBJECTIVE

To determine the prevalence of isolated thoracic degeneration on magnetic resonance imaging (MRI), demographic factors and imaging features, as well as the patient-reported quality of life outcomes associated with this condition.

SUMMARY OF BACKGROUND DATA

Thoracic intervertebral discs are least susceptible to disc degeneration (DD) and may represent a manifestation of "dysgeneration." These discs may never be hydrated from the beginning and seem hypointense on MRI.

PATIENTS AND METHODS

A population-based MRI study of 2007 volunteers was conducted. Each disc from C2/3 to L5/S1 was measured by Pfirrmann and Schneiderman grading. Disc herniation, Schmorl node (SN), high-intensity zones (HIZ), and Modic changes were studied. DD was defined by Pfirrmann 4 or 5. patient-reported quality of life scores, including a 36-item short-form questionnaire and visual analog scale for low back pain, were recorded. Subjects were divided into "isolated thoracic degeneration" (only thoracic segment) and "tandem thoracic degeneration" (thoracic with other segments). The association between imaging findings and isolated thoracic degeneration was determined using multivariate logistic regression.

RESULTS

The mean age of the subjects was 50.0 ± 0.5 and 61.4% were females (n = 1232). Isolated thoracic degeneration was identified in 2.3% of the cohort. Factors associated with isolated thoracic degeneration included lower age, C6/7 HIZ, T8/9 HIZ, and T8/9 SN. Factors associated with tandem thoracic degeneration included L4/5 posterior bulging. The thoracic and lumbar tandem degeneration group demonstrated higher bodily pain, despite a lower visual analog scale, and a higher physical component score of the 36-item short form.

CONCLUSIONS

Isolated thoracic degeneration demonstrated an earlier age of onset, mostly involving the mid-thoracic region (T5/6-T8/9), and in association with findings such as SN. Subjects with tandem thoracolumbar degeneration had less severe lumbar DD and low back pain as compared with those with isolated lumbar degeneration. This paints the picture of "dysgeneration" occurring in the thoracic and lumbar spine.

LEVEL OF EVIDENCE

1.

Association between modic changes, disc degeneration, and pelvic incidence-lumbar lordosis mismatch in a large population based cohort: the Wakayama spine study

PURPOSE

Sagittal plane alignment is crucial for treating spinal malalignment and low back pain. Pelvic incidence-lumbar lordosis (PI-LL) mismatch is commonly used to evaluate clinical outcomes in patients with sagittal malalignment. The association between PI-LL mismatch and changes surrounding the intervertebral disc is very important to understand the compensatory mechanisms involved. This study aimed to examine the association between PI-LL mismatch and magnetic resonance imaging (MRI) changes surrounding the intervertebral disc in a large population-based cohort.

METHODS

We evaluated participants from the second Wakayama Spine Study, recruiting the general population aged 20 years or older, irrespective of sex, who were registered residents in one region in 2014. In total, 857 individuals underwent an MRI of the whole spine; however, 43 MRI results were not included due to incomplete or inadequate quality images. PI-LL mismatch was defined as > 11°. We compared the MRI changes, such as Modic change (MC), disc degeneration (DD), and high-intensity zones (HIZ), between PI-LL mismatch and non-PI-LL mismatch groups. Multivariate logistic regression analysis was conducted to determine the association between the MRI changes and PI-LL mismatch with adjustment for age, sex, and body mass index in the lumbar region and at each level.

RESULTS

A total of 795 participants (243 men, 552 women, mean age 63.5 ± 13.1 years old) were evaluated; 181 were included in the PI-LL mismatch group. MC and DD in the lumbar region were significantly higher in the PI-LL mismatch group. MC in the lumbar region was significantly associated with PI-LL mismatch (odds ratio (OR); 1.81, 95% confidence interval (CI) 1.2-2.7). MC at each level was significantly associated with PI-LL mismatch (OR; 1.7-1.9, 95%CI 1.1-3.2), and DD at L1/2, L3/4, and L4/5 was associated with PI-LL mismatch (OR; 2.0- 2.4. 95%CI 1.2-3.9).

CONCLUSION

MC and DD were significantly associated with PI-LL mismatch. Therefore, profiling MC may be helpful in improving the targeted treatment of LBP associated with the adult spinal deformity.

Effects of cycling on the morphology and spinal posture in professional and recreational cyclists: a systematic review

The aim was to know if cycling affects spinal morphology in postures off the bicycle, such as adapting the spinal curvatures on the bicycle depending on the handlebar type and position on the handlebars. A systematic review was conducted following the PRISMA guidelines. The studies selected met the following criteria: a) the study design was cross-sectional or longitudinal (experimental or cohorts); b) the study evaluated the sagittal morphology of the spine on the bicycle; c) the study included healthy and trained participants without injuries or cyclists reporting low back pain. Fifteen studies reported that a greater pelvic tilt was observed that when the handlebar was in a lower position. Sixteen studies found that lumbar kyphosis was greater when the handlebar grip was lower and farther from the saddle. Twelve studies reported that a tendency towards greater thoracic flexion as the time spent pedalling on the bicycle increased. In conclusion, the practice of cycling produces adaptations in the morphology of the spine of the cyclist compared to non-cyclists, such as an increase in pelvic tilt and a greater capacity for lumbar flexion in trunk flexion positions, and a greater thoracic kyphosis in the standing position.

Association between sagittal alignment and loads at the adjacent segment in the fused spine: a combined clinical and musculoskeletal modeling study of 205 patients with adult spinal deformity

PURPOSE

Sagittal malalignment is a risk factor for mechanical complications after surgery for adult spinal deformity (ASD). Spinal loads, modulated by sagittal alignment, may explain this relationship. The aims of this study were to investigate the relationships between: (1) postoperative changes in loads at the proximal segment and realignment, and (2) absolute postoperative loads and postoperative alignment measures.

METHODS

A previously validated musculoskeletal model of the whole spine was applied to study a clinical sample of 205 patients with ASD. Based on clinical and radiographic data, pre-and postoperative patient-specific alignments were simulated to predict loads at the proximal segment adjacent to the spinal fusion.

RESULTS

Weak-to-moderate associations were found between pre-to-postop changes in lumbar lordosis, LL (r =  - 0.23, r =  - 0.43; p < 0.001), global tilt, GT (r = 0.26, r = 0.38; p < 0.001) and the Global Alignment and Proportion score, GAP (r = 0.26, r = 0.37; p < 0.001), and changes in compressive and shear forces at the proximal segment. GAP score parameters, thoracic kyphosis measurements and the slope of upper instrumented vertebra were associated with changes in shear. In patients with T10-pelvis fusion, moderate-to-strong associations were found between postoperative sagittal alignment measures and compressive and shear loads, with GT showing the strongest correlations (r = 0.75, r = 0.73, p < 0.001).

CONCLUSIONS

Spinal loads were estimated for patient-specific full spinal alignment profiles in a large cohort of patients with ASD pre-and postoperatively. Loads on the proximal segments were greater in association with sagittal malalignment and malorientation of proximal vertebra. Future work should explore whether they provide a causative mechanism explaining the associated risk of proximal junction complications.

A Comparison of Two Forward Head Posture Corrective Approaches in Elderly with Chronic Non-Specific Neck Pain: A Randomized Controlled Study

Forward head posture (FHP) is a common postural displacement that is significantly associated with neck pain, with higher risks of having neck pain in female and older populations. This study investigated the effect of two different forward head posture (FHP) interventions in elderly participants with poor posture and non-specific neck pain. Sixty-six elderly participants with a craniovertebral angle (CVA) < 50° were randomized into either a Chiropractic Biophyics® (CBP®) or a standardized exercise based FHP correction group (Standard Group). Both groups were treated for 18 sessions over a 6-week period. A 3-month post-treatment follow-up was also assessed with no further interventions. The CBP group received a mirror image® exercise and a Denneroll™ cervical traction orthotic (DCTO); the standard group performed a protocol of commonly used stretching and strengthening exercises for the neck. Both groups received 30 min of their respective interventions per session. The primary outcome was the CVA, with secondary outcomes including pain intensity, Berg balance score (BBS), head repositioning accuracy (HRA), and cervical range of motion (CROM). After 18 sessions (6 weeks later), the CBP group had statistically significant improvement in the CVA (p < 0.001), whereas the standard group did not. In contrast, both groups showed improved functional measurements on the BBS and HRA as well as improved pain intensity. However, at the 3-month follow-up (with no further treatment), there were statistically significant differences favoring the CBP group for all outcomes (p < 0.001). The differences in the between group outcomes at the 3-month follow-up indicated that the improved outcomes were maintained in the CBP group, while the standard group experienced regression of the initially improved outcomes at 6 weeks. It is suggested that the improvement in the postural CVA (in the CBP group but not in the standard group) is the driver of superior and maintained pain and functional outcomes.

Relationship between Intervertebral Disc Compression Force and Sagittal Spinopelvic Lower Limb Alignment in Elderly Women in Standing Position with Patient-Specific Whole Body Musculoskeletal Model

The intervertebral disc loading based on compensated standing posture in patients with adult spinal deformity remains unclear. We analyzed the relationship between sagittal alignment and disc compression force (Fm). In 14 elderly women, the alignment of the sagittal spinopelvic and lower extremities was measured. Fm was calculated using the Anybody Modeling System. Patients were divided into low sagittal vertical axis (SVA) and high SVA groups. Comparisons between the two groups were performed and the relationship between the Fm and each parameter was examined using Spearman's correlation coefficient (r). The mean lumbar Fm in the high SVA group was 67.6%; significantly higher than that in the low SVA group (p = 0.046). There was a negative correlation between cervical Fm with T1 slope (r = -0.589, p = 0.034) and lumbar Fm with lumbar lordosis (r = -0.566, p = 0.035). Lumbar Fm was positively correlated with center of gravity-SVA (r = 0.615, p = 0.029), T1 slope (r = 0.613, p = 0.026), and SVA (r = 0.612, p = 0.020). The results suggested sagittal malalignment increased the load on the thoracolumbar and lower lumbar discs and was associated with cervical disc loading.

Does Improvement towards a Normal Cervical Sagittal Configuration Aid in the Management of Lumbosacral Radiculopathy: A Randomized Controlled Trial

A randomized controlled study with a six-month follow-up was conducted to investigate the effects of sagittal head posture correction on 3D spinal posture parameters, back and leg pain, disability, and S1 nerve root function in patients with chronic discogenic lumbosacral radiculopathy (CDLR). Participants included 80 (35 female) patients between 40 and 55 years experiencing CDLR with a definite hypolordotic cervical spine and forward head posture (FHP) and were randomly assigned a comparative treatment control group and a study group. Both groups received TENS therapy and hot packs, additionally, the study group received the Denneroll cervical traction orthotic. Interventions were applied at a frequency of 3 x per week for 10 weeks and groups were followed for an additional 6-months. Radiographic measures included cervical lordosis (CL) from C2–C7 and FHP; postural measurements included: lumbar lordosis, thoracic kyphosis, trunk inclination, lateral deviation, trunk imbalance, surface rotation, and pelvic inclination. Leg and back pain scores, Oswestry Disability Index (ODI), and H-reflex latency and amplitude were measured. Statistically significant differences between the groups at 10 weeks were found: for all postural measures, CL (p = 0.001), AHT (p = 0.002), H-reflex amplitude (p = 0.007) and latency (p = 0.001). No significant difference for back pain (p = 0.2), leg pain (p = 0.1) and ODI (p = 0.6) at 10 weeks were identified. Only the study group’s improvements were maintained at the 6-month follow up while the control groups values regressed back to baseline. At the 6-month follow-up, it was identified in the study group that improved cervical lordosis and reduction of FHP were found to have a positive impact on 3D posture parameters, leg and back pain scores, ODI, and H-reflex latency and amplitude.

Should adjacent asymptomatic lumbar disc herniation of L5-S1 isthmic spondylolisthesis be simultaneously rectified? Evaluation of postoperative spino-pelvic sagittal balance and functional outcomes

Background

This study aimed to analyze the efficacy of the simultaneous rectification of adjacent asymptomatic lumbar disc herniation (asLDH) of L5-S1 isthmic spondylolisthesis (IS).

Methods

One hundred and forty-eight patients with L5-S1 IS, and simultaneous L4-5 asLDH, were recruited between January 2012 and December 2017, for this study. Group A: seventy-two patients received PLIF at L5-S1. Group B: seventy-six patients received PLIF at L4-S1. The radiographic outcomes were assessed via the lumbar lordosis (LL), segmental lordosis (SL), sacral slope (SS), pelvic incidence (PI), pelvic tilt (PT), PI-LL and slip degree (SD). The functional outcomes were evaluated via the visual analog scale (VAS), Oswestry disability index (ODI), and reoperation rate. The potential risk hazards for reoperation were identified using both uni- and multivariate logistic regression analyses.

Results

The postoperative LL, SL, PT, SS, SD, VAS, and ODI exhibited vast improvements (P < 0.05). Relative to Group A, Group B exhibited markedly better LL, SL, PT, PI-LL,VAS and ODI scores at the final follow-up (P < 0.05). Group B also achieved better SD values post surgery than Group A (P < 0.05). The reoperation rate was remarkably elevated in Group A, compared to Group B (P < 0.05). The multivariate logistic regression analysis showed the L4-5 asLDH grade was a stand-alone risk hazard for reoperation, whereas, pre-SL and pre-LL offered protection against reoperation (P < 0.05).

Conclusions

L4-S1 PLIF is recommended to correct asLDH in L5-S1 IS patients, with high-grade disc herniation and abnormal sagittal alignment.

Association between Roussouly classification and characteristics of lumbar degeneration

OBJECTIVE

Different sagittal morphologies are associated with various lumbar degenerative diseases. In this paper, we aim to investigate the association between Roussouly classification and the characteristics of lumbar degeneration.

METHODS

A total of 273 patients with lumbar degeneration diseases were included in this cross-sectional study. The patients were divided into four groups according to the Roussouly classification. The degeneration of intervertebral disc (IVD) and facet joint was evaluated by Pfirrmann and Pathria grading scales, respectively. To elucidate the degenerative characteristics of diverse lumbar sagittal morphologies by comparing the degeneration degree of IVDs and facet joints between four groups.

RESULTS

The differences in sacral slope (SS) and lumbar lordosis (LL) were significant between the four groups (P < 0.05). Type 2 lumbar spine had the highest proportion of high-grade disc degeneration compared with other subtypes (P < 0.05), types 1 and 2 had a higher proportion of high-grade degeneration than types 3 and 4 (P < 0.05). However, type 4 lumbar spine had the highest proportion of high-grade facet joint degeneration compared with other subtypes (P < 0.05), types 3 and 4 had a higher proportion of high-grade degeneration than types 1 and 2 (P < 0.05).

CONCLUSIONS

Risks of advanced disc degeneration are higher for subjects with lumbar spine morphologies of Roussouly type 1 or type 2, especially for subjects with type 2 lumbar spine. Whereas, high-grade degeneration of facet joint tends to occur in type 3 and type 4 lumbar spine, especially for subjects with type 4 lumbar spine.

Sagittal spine disposition and pelvic tilt during outdoor fitness equipment use and their associations with kinanthropometry proportions in middle-aged and older adults

BACKGROUND

Outdoor fitness training has become popular as a tool for improving the health, especially middle-aged and older adults. For this purpose, outdoor fitness equipment (OFE) have been installed in public areas. However, their safety and effectiveness are still unknown. The aim of the present research was to analyze the sagittal disposition of the spine and pelvic tilt during the use of OFE, and to determine the influence of anthropometric variables on these factors in middle-aged and older adults.

METHODS

Seventy healthy volunteers, 56 women and 14 men (age: 63.14 ± 8.19 years) participated in the study. Sagittal spine disposition and pelvic tilt were measured using a Spinal Mouse®, in the relaxed standing position, and during the use of the OFE. In addition, kinanthropometry variables were also measured according to the guidelines of the International Society for the Advancement of Kinanthropometry.

RESULTS

Regarding thoracic kyphosis, a significant decrease was found in thoracic kyphosis in the initial position (IP) in single bonny rider (SBR) (p = 0.006) and row (p = 0.046), and a significant increase in the final position (FP) in the row (p = 0.011), surfboard (p < 0.001) and air walker (p = 0.027) machines. In relation to the lumbar curvature and pelvic tilt, a significant decrease in lumbar lordosis and a decrease in pelvic anteversion were observed in the IP and FP in SBR and row; and in the bike (p < 0.001) machine. In the surfboard machine, a significant decrease in lumbar lordosis was found (p = 0.002), with no changes in pelvic tilt. According to the multiple linear regression analysis, the subjects with a higher cormic index and height were more at risk of increasing their thoracic kyphosis, decreasing lumbar lordosis and/or decreasing pelvic anteversion towards pelvic retroversion.

CONCLUSIONS

Middle-aged and older adults show spinal misalignments when using the OFE with respect to the standing position, showing a decrease in the thoracic kyphosis in IP of SBR and ROW, and a significant increase in the surfboard and air walker, and in the FP of Row, in the lumbar lordosis in all the OFE in sitting and some in standing, and in the pelvic anteversion in all the OFE in sitting. The variables height and the cormic index explained most of the changes in sagittal spine disposition.

Influence of Lumbar Lordosis on Posterior Rod Strain in Long-Segment Construct During Biomechanical Loading: A Cadaveric Study

Objective

The lordotic shape of the lumbar spine differs substantially between individuals. Measuring and recording strain during spinal biomechanical tests is an effective method to infer stresses on spinal implants and predict failure mechanisms. The geometry of the spine may have a significant effect on the resultant force distribution, thereby directly affecting rod strain.

Methods

Seven fresh-frozen cadaveric specimens (T12-sacrum) underwent standard (7.5 Nm) nondestructive sagittal plane tests: flexion and extension. The conditions tested were intact and pedicle screws and rods (PSR) at L1-sacrum. The posterior right rod was instrumented with strain gauges between L3–4 (index level) and the L5–S1 pedicle screw. All specimens underwent lateral radiographs before testing. Lordotic angles encompassing different levels (L5–S1, L4–S1, L3–S1, L2–S1, and L1–S1) were measured and compared with rod strain. Data were analyzed using Pearson correlation analyses.

Results

Strong positive correlations were observed between lordosis and posterior rod strain across different conditions. The L3–S1 lordotic angle in the unloaded intact condition correlated with peak rod strain at L3–4 with PSR during flexion (R=0.76, p=0.04). The same angle in the unloaded PSR condition correlated with peak strain in the PSR condition during extension (R=-0.79, p=0.04). The unloaded intact L2–S1 lordotic angle was significantly correlated with rod strain at L3–4 in the PSR condition during flexion (R=0.85, p=0.02) and extension (R=-0.85, p=0.02) and with rod strain at L5–S1 in the PSR condition during flexion (R=0.84, p=0.04).

Conclusion

Lordosis measured on intact and instrumented conditions has strong positive correlations with posterior rod strain in cadaveric testing.

Global Sagittal Balance of Spine in Asymptomatic Controls: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the global sagittal balance of spine (GSBS) in asymptomatic controls.

METHODS

PubMed, Scopus, Cochrane library, and Web of Science searched up to July 2020. Studies were screened for the GSB parameters including T1 pelvic angle (TPA), spinosacral angle (SSA), sagittal vertical axis (SVA), C7/sacrofemoral distance ratio (Barrey index), odontoid hip axis (OD-HA), and Full Balance Index (FBI) as measured in asymptomatic participants. A meta-analysis was performed to synthesize pooled estimates. Heterogeneity and publication bias were assessed.

RESULTS

Overall, 76 studies were identified including 12,169 participants (54.7% female) with mean age ranges from 12.0 to 72.9 years old. We used the Newcastle-Ottawa Scale (NOS) to evaluate the quality of studies included in this review. Begg's test did not indicate obvious publication bias. The pooled analysis reveals that the mean (standard deviation) normative values were: 1) age ˃18 years, SSA (°), 127.6 (0.89); SVA absolute value (millimeters), 13.1 (1.13); TPA (°), 9.8 (1.13); T1SPI (°), -4.3 (0.57); and Barrey index absolute value, 0.51 (0.3). The mean value of the OD-HA (°) was reported 2.9 (1.6), and the FBI average value was less than 5°. 2) Age ≤18 years, SSA (°), 132.1 (8.3); SVA absolute value (millimeters), 11.9 (2.0); and Barrey index, -0.7 (8.3). A significant difference was observed between the 2 age groups based on SVA and SSA.

CONCLUSIONS

This paper presents normative data on TPA, SSA, SVA, Barrey index, OD-HA, and FBI as a reference for evaluating/measuring a GSB of spine in asymptomatic controls.

Load Distribution in the Lumbar Spine During Modeled Compression Depends on Lordosis

Excessive or incorrect loading of lumbar spinal structures is commonly assumed as one of the factors to accelerate degenerative processes, which may lead to lower back pain. Accordingly, the mechanics of the spine under medical conditions, such as scoliosis or spondylolisthesis, is well-investigated. Treatments via both conventional therapy and surgical methods alike aim at restoring a "healthy" (or at least pain-free) load distribution. Yet, surprisingly little is known about the inter-subject variability of load bearings within a "healthy" lumbar spine. Hence, we utilized computer tomography data from 28 trauma-room patients, whose lumbar spines showed no visible sign of degeneration, to construct simplified multi-body simulation models. The subject-specific geometries, measured by the corresponding lumbar lordosis (LL) between the endplates of vertebra L1 and the sacrum, served as ceteris paribus condition in a standardized forward dynamic compression procedure. Further, the influence of stimulating muscles from the M. multifidus group was assessed. For the range of available LL from 28 to 66°, changes in compressive and shear forces, bending moments, as well as facet joint forces between adjacent vertebrae were calculated. While compressive forces tended to decrease with increasing LL, facet forces were tendentiously increasing. Shear forces decreased between more cranial vertebrae and increased between more caudal ones, while bending moments remained constant. Our results suggest that there exist significant, LL-dependent variations in the loading of "healthy" spinal structures, which should be considered when striving for individually appropriate therapeutic measures.

Association between spinal alignment and biochemical composition of lumbar intervertebral discs assessed by quantitative magnetic resonance imaging

Background

To evaluate potential associations between spinopelvic parameters and the biochemical composition of lumbar intervertebral discs using quantitative magnetic resonance imaging in asymptomatic young adults.

Methods

Our study group comprised 93 asymptomatic volunteers aged 20-40 years (49 women and 44 men). Lumbar spine T2-weighted images and T2 relaxometry were acquired on a 1.5T MRI scanner. Spinopelvic parameters including sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis, thoracic kyphosis, thoracolumbar alignment, sagittal vertical axis, spinosacral angle, C2 pelvic angle, and T1S1 and L1S1 length were measured on panoramic spine radiographs.

Results

Lumbar lordosis decrease correlates with discrete dehydration of nucleus pulposus at all lumbar levels. Also low values of sacral slope, pelvic tilt, pelvic incidence, thoracic kyphosis and spinosacral angle were associated with decrease of T2 relaxation times on annulus fibrosus.

Conclusions

In conclusion, spinopelvic parameters presented a discrete association with lumbar disc composition and water content.

No evidence of a correlation between lumbar spinal subtypes and intervertebral disc degeneration among asymptomatic middle-aged and aged patients

The aim of the present study was to identify whether lumbar spinal subtypes (LSS) were associated with lumbar disc degeneration (LDD) among asymptomatic middle-aged and aged subjects. A cohort of 158 asymptomatic Chinese adults aged >40 years was recruited and 97 volunteers that met the inclusion criteria with complete information available were selected for inclusion. According to spinal morphology, volunteers were divided into four subtypes based on the classification of Roussouly. After baseline information was collected and spinopelvic parameters were measured, the data were compared among the four groups. According to the Pfirrmann classification, the degree of LDD was evaluated at each level on the MRI. For grades I-V, LDD at each level was effectively compared. Each of the four LSS from I to IV according to Roussouly classification from types I to IV were comprised of 25 (25.8%), 19 (19.6%), 38 (39.2%) and 15 (15.5%) of volunteers, respectively. Lumbar lordosis, sacral slope and pelvic incidence were significantly different among the four sub-types (P<0.001 for each), but no difference in pelvic tilt was observed (P=0.21). From types I to IV LSS, the proportion of disc degeneration was found to be 44, 52, 50 and 48%, respectively, which exhibited no statistically significant difference among LSS. No correlation between LSS and intervertebral disc degeneration was obtained among the asymptomatic middle-aged and aged subjects. The present study provides a reference for spinal surgery and indicated that additional risk factors should be assessed in the asymptomatic population of this age group, particularly in terms of differentially expressed genes.

A spatio-temporal and kinematic description of self-selected walking in adults with Achondroplasia

BACKGROUND

Achondroplasia is characterised by a shorter appendicular limb to torso ratio, compared to age matched individuals of average stature (controls). Despite the well documented shorter leg length of individuals with compared to controls, there are few complete descriptions of gait kinematics reported for the population.

AIM

The aim of this study was to report the spatio-temporal and kinematic characteristics of self-selected walking (SSW) in a group with Achondroplasia (N = 10) and age matched group without Achondroplasia (controls, N = 17).

METHOD

Whole body 3D analysis of both groups was conducted using a 14 camera VICON system. Spatio-temporal and kinematic variables were determined through a Plug-in-Gait model. SSW was obtained from an average of three trials equating to a total of ∼120 m walking.

RESULTS

The group with Achondroplasia were 23 % slower (P < 0.001), had a 29 % shorter stride length (P < 0.001) and a 13 % higher stride frequency (P < 0.001) compared to controls. There were no differences in time normalised temporal measures of left toe off (P = 0.365), right heel contact (P = 0.442) or the duration of double support (P = 0.588) between groups. A number of discrete joint kinematic differences existed between groups, resulting in the group with Achondroplasia having more 'flexed' lower limbs than controls throughout the gait cycle.

CONCLUSION

Differences in absolute spatio-temporal variables between groups is likely due to the shorter leg length of the group with Achondroplasia, while their more flexed position of the lower limbs may facilitate toe-clearance during the swing phase.

Association between Spinopelvic Alignment and Lumbar Intervertebral Disc Degeneration Quantified with Magnetic Resonance Imaging T2 Mapping in Patients with Chronic Low Back Pain

Introduction

Although intervertebral disc degeneration (IVDD) and spinopelvic malalignment are likely key structural features of spinal degeneration and chronic low back pain (CLBP), the correlation analysis has not been fully conducted. This cross-sectional quantitative magnetic resonance imaging (MRI) T2 mapping study aimed to elucidate the association between IVDD and spinopelvic alignment in CLBP patients.

Methods

The subjects included 45 CLBP patients (19 men and 26 women; mean age, 63.8 ± 2.0 years; range, 41-79 years). The T2 values of the anterior annulus fibrosus (AF), the nucleus pulposus (NP), and the posterior AF were evaluated using MRI T2 mapping. We compared the possible correlations of spinopelvic parameters with T2 values of anterior AF, NP, and posterior AF using Pearson's correlation coefficient analysis. T2 values in these regions were classified into upper (L1-L2 and L2-L3), middle (L3-L4), and lower (L4-L5 and L5-S1) disc levels, and we analyzed the correlations with spinopelvic parameters.

Results

There were significant correlations of the anterior AF T2 values with lumbar lordosis (r = 0.51, p < 0.01), sacral slope (r = 0.43, p < 0.01), sagittal vertical axis (r = −0.40, p < 0.01), and pelvic tilt (r = −0.33, p < 0.01). In all lumbar levels, T2 values of anterior AF had significantly positive correlation with LL and significantly negative correlation with SVA. In lower disc level, T2 values of anterior AF had significantly positive correlation with SS and significantly negative correlation with PT. T2 values of NP and posterior AF had no significant correlations with spinopelvic parameters in all lumbar disc levels.

Conclusions

In summary, this study indicated that the anterior AF degeneration is associated with hypolordosis of the lumbar spine, anterior translation of the body trunk, and posterior inclination of the pelvis in CLBP. Anterior AF degeneration in all lumbar disc levels was associated with hypolordosis of the lumbar spine and anterior translation of the body trunk. Anterior AF degeneration in lower disc level was associated with posterior inclination of the pelvis.

Different spinal subtypes with varying characteristics of lumbar disc degeneration at specific level with age: a study based on an asymptomatic population

Background

The relationship between spinal sagittal subtypes and lumbar disc degeneration is unclear. Thus, we aimed to investigate the relationship between lumbar intervertebral disc degeneration and age in asymptomatic healthy individuals with different sagittal alignments.

Methods

In this cross-sectional observational study, we examined 209 asymptomatic young and middle-aged volunteers (123 women and 86 men) who were divided into the following three groups according to age: groups A (20–30 years), B (31–40 years), and C (41–50 years). The volunteers underwent full-spine standing lateral radiography and magnetic resonance imaging (MRI, 3.0 T) of the lumbar spine. Based on panoramic radiography, two observers measured the spinopelvic parameters and classified the spine into Roussouly subtypes. The degree of disc degeneration was assessed based on T2-weighted images according to the Pfirrmann classification.

Results

There was a statistically significant difference in the degree of degeneration of type I spine between groups B and C at L4-L5 (P < 0.03) and L5-S1 (P < 0.01) and between groups A and C at L1-L2 (P < 0.04) and L4-L5 (P < 0.01). The degeneration degree of type II spine at all levels were significantly different between groups A and C. No statistically significant difference was found between groups A and B in all subtypes except for type II spine at L1-L2 (P < 0.04). A significant difference was found at four levels between groups B and C in type III spine (P < 0.05) and between groups A and C. For type IV spine, there was a significant difference in the degree of degeneration at L4-L5 (P < 0.02) between groups A and C. Moreover, almost all single parameters were not strongly correlated with the degree of disc degeneration.

Conclusion

The different spinal subtypes have characteristics of lumbar disc degeneration at specific levels with age. We considered that spinal classification could be used as a predictor of lumbar disc degeneration. Our data may be helpful to increase awareness of the relationship between spinal subtypes and lumbar disc degeneration.

Level of evidence

3

Sagittal spinal morphotype assessment in 8 to 15 years old Inline Hockey players

Background

Physiological sagittal spinal curvatures play an important role in health and performance in sports. For that reason, several scientific studies have assessed spinal morphology in young athletes. However, to our knowledge, no study has assessed the implications of Inline Hockey (IH) practice on sagittal integrative spinal morphotype in adolescent players.

Objectives

The aims of the present study were to describe habitual sagittal spinal posture in young federated IH players and its relationship with training load and to determine the sagittal integrative spinal morphotype in these players.

Methods

An observational analysis was developed to describe the sagittal spinal morphotype in young federated IH players. A total of 74 IH players from the Technification Plan organized by the Skating Federation of the Valencian Community (aged from 8 to 15 years) participated in the study. Thoracic and lumbar curvatures of the spine were measured in a relaxed standing position (SP), in a slump sitting position (SSP) and in maximum flexion of the trunk (MFT) to determine the "Sagittal Integrative Morphotype" of all players. An unilevel inclinometer was used to quantify the sagittal spinal curvatures. The Hip Joint Angle test was used to quantify the Lumbo-Horizontal angle in flexion (L-H fx) of all participants with a goniometer.

Results

When thoracic curvature was analyzed according to normality references, it was found that 64.9% of IH players had thoracic hyperkyphosis in a SSP, while 60.8% and 74.3% of players were classified as normal in a SP and in MFT, respectively. As for the lumbar curve, 89.2% in a SP and 55.4% in MFT were normal, whereas 68.9% of IH players presented lumbar hyperkyphosis in a SSP. Regarding the "Sagittal Integrative Morphotype," only 17.6% of players were classified as "Normal" in the three measured positions for the thoracic curve, while 37.8% had "Thoracic Hyperkyphosis" and 41.8% presented "Functional Thoracic Hyperkyphosis." As for the "Sagittal Integrative Lumbar Morphotype," only 23% of athletes had a normal curve in the three positions, whereas 66.2% presented "Functional Lumbar Hyperkyphosis." When the L-H fx was evaluated, the results showed that only 16.2% of the athletes were classified as normal.

Conclusions

Federative IH practice seems to cause specific adaptations in spinal sagittal morphotype. Taking into account the "Sagittal Integrative Morphotype" only 17.6% IH players presented "Normal Morphotype" with a normal thoracic kyphosis in the three measured positions, while only 23% IH players presented "Normal Morphotype" with a normal lumbar curvature in the three assessed positions. Furthermore, only 16.2% of IH players showed normal pelvic tilt. Exercise programs to prevent or rehabilitate these imbalances in young IH players are needed.

Using the Scoliometer and a Surface Topography Apparatus to Check if Back Trunk Asymmetry Changes in Children and Adolescents in the Forward Flexion and Standing Erect Positions

Background

The purpose of this study is to evaluate the effects of the forward bending (FB) test versus the standing erect (SE) position on back trunk asymmetry (TA). The Scoliometer in the FB position and the 4D Formetric (4DF; Diers International, Schlangenbad, Germany) readings in the SE position were assessed.

Method

The angle of trunk inclination (ATI) was measured at the midthoracic, thoracolumbar, and lumbar levels using the Scoliometer in the FB position and the 4DF in the SE position.

A total of 134 subjects attending the scoliosis clinic (86 girls and 48 boys), age ranging from seven to 18 years, were assessed. The children and adolescents were divided into three groups according to the severity of TA, symmetric group 1 (0-2 degrees), asymmetry group 2 (2 to 6 degrees), and group 3 having asymmetry of seven or more degrees. Children with leg length discrepancy were excluded from the study.

The IBM SPSS v.20 package (IBM Corp., Armonk, NY) was used for analysis.

Results

At the midthoracic level comparing the Scoliometer to 4DF readings in males in group 1, the Wilcoxon signed ranks test was p=0.451 while for the Spearman’s Rho, it was -0.138; in group 2, p=0.184 and Rho=0.204; and in group 3, p=0.109 and Rho=0.500. For females in group 1, p=0.000 while Rho=0.003; in group 2, p=0.008 and Rho=0.000, and in group 3, p=0.003 while Rho=0.642.

At the thoracolumbar level in males for group 1, p=0.004 and Rho=-0.517; in group 2, p=0.006 and Rho=0.000; and in group 3, p=0.043 while Spearman’s Rho=0.053. For females in group 1, p=0.000 and Rho=-0.095; in group 2, p=0.000 and Rho=-0.171; in group 3, p=0.001 while Rho= -0.081. At the lumbar level for males in group 1 p=0.000 while Rho=0.149; in group 2, p=0.003 and Rho=0.373; while in group 3, p=0.109 and Rho= (-). For females in group 1, p=0.000 while Rho=-0.072; in group 2, p=0.001 and Rho=0.168; and in group 3, p=0.068 while Rho=0.500.

Conclusion

The results of this study show that the back TA in children and adolescents is not similar in the FB and SE positions. This phenomenon probably is attributed to the complicated trunkal (spinal, thoracic, and pelvic) anatomy, and the results of this study may be used as a useful foundation for further understanding of torso dynamics.

Repeat Radiography in Monitoring Structural Changes in the Treatment of Spinal Disorders in Chiropractic and Manual Medicine Practice: Evidence and Safety

There is substantial evidence for normal relationships between spine and postural parameters, as measured from radiographs of standing patients. Sagittal balance, cervical lordosis, thoracic kyphosis, lumbar lordosis, pelvic tilt, and the more complex understanding of the interrelations between these essential components of normal stance have evolved to where there are known, established thresholds for normalcy. These spinal parameters are reliably measured from X-ray images and serve as goals of care in the treatment of spine and postural disorders. Initial and follow-up spinal imaging by X-ray is thus crucial for the practice of contemporary and evidence-based structural rehabilitation. Recent studies have demonstrated that improvement in the spine and posture by nonsurgical methods offers superior long-term patient outcomes versus conventional methods that only temporarily treat pain/dysfunction. Low-dose radiation from repeated X-ray imaging in treating subluxated patients is substantially below the known threshold for harm and is within background radiation exposures. Since alternative imaging methods are not clinically practical at this time, plain radiography remains the standard for spinal imaging. It is safe when used in a repeated fashion for quantifying pre–post spine and postural subluxation and deformity patterns in the practice of structural correction methods by chiropractic and other manual medicine practices.

Reduction of thoraco-lumbar junctional kyphosis, posterior sagittal balance, and increase of lumbar lordosis and sacral inclination by Chiropractic BioPhysics® methods in an adolescent with back pain: a case report

[Purpose] To present the structural improvement of an excessive junctional thoracolumbar kyphosis and related biomechanical parameters in an adolescent. [Participant and Methods] A 16 year old female presented with chronic back pains. Radiographic assessment revealed excessive posterior sagittal balance and thoracolumbar kyphosis and reduced lumbar lordosis and sacral inclination. Chiropractic BioPhysics^® technique including mirror image^®, anterior thoracic translation and thoracolumbar hyperextension traction was performed as well as spinal manipulation and postural exercises over an 8-week period. [Results] After 24 in-office treatments and a daily home program the patient reported a minimization of back pains and a better mood. Follow-up X-rays demonstrated a 48 mm reduction of posterior sagittal balance, a 22° reduction of thoracolumbar kyphosis, an 11° increase in lumbar lordosis, and a 10° increase in sacral inclination. [Conclusion] This is the first case documenting the non-surgical reduction of excessive thoracolumbar junctional kyphosis and related biomechanical parameters in an adolescent. Precise analysis of radiologic assessment for adolescents presenting with back pains is advised and are safe for the screening of postural disorders. There is a growing evidence base for the Chiropractic BioPhysics^® technique approach in the correction of lumbar spine disorders; more research is encouraged to further evaluate this unique treatment.

Distribution of Modic changes in patients with low back pain and its related factors

BACKGROUND

To summarize the clinical distribution of Modic changes in patients with low back pain and explore the related factors.

METHODS

A total of 153 patients were enrolled. Gender, age, disk degeneration, herniation, involved segments, lumbar lordosis angle, and endplate concave angle were recorded, respectively. Patients were divided into two or more groups according to a different classification. The relevant factors were studied with a multivariate logistic regression analysis to analyze their correlation.

RESULTS

A total of 35 patients with type I changes, 110 patients with type II changes, and 8 patients with type III changes. In total, 204 disks were found with Modic changes, L1/2 (10 disks), L2/3 (18 disks), L3/4 (17 disks), L4/5 (76 disks), and L5/S1 (81 disks). Type I changes were distributed mainly under the age of 50. Multivariate regression showed that gender, age, disk degeneration, lumbar lordosis, L4/5 segment lordosis angle, and L5 lower endplate concave angle were related with different types of Modic changes. The regression equation Y = 2.410 - 1.361S - 0.633A - 0.654P + 1.106L - 0.990D (Y means type I changes, S means gender, A means age, P means disk degeneration, L means L4/5 segment lordosis angle, and D means L5 upper endplate concave angle). The OR values were S = 0.256, A = 0.531, P = 0.520, L = 3.022, D = 0.372, respectively.

CONCLUSIONS

Type II changes are the most common, followed by type I. Modic changes mostly occur in L4/5 and L5/S1; young, male, lower-grade disk degeneration, normal physiological curvature of the lumbar spine, and normal endplate concave angle were associated with type I changes; gender and lumbar curvature were the most relevant factors for different types.

Significance of spine stability criteria on trunk muscle forces following unilateral muscle weakening: A comparison between kinematics-driven and stability-based kinematics-driven musculoskeletal models

Two optimization-driven approaches were employed to develop kinematics-driven (KD) and stability-based kinematics-driven (SKD) musculoskeletal models of an adult thoracolumbar to ascertain the significance of spine stability in holding the upright-standing posture after muscular disuse atrophy. Both models were used to estimate muscle forces of the trunk with intact and unilaterally reduced longissimus thoracis pars thoracic (LGPT) and multifidus lumborum (MFL) muscles strength. A finite element model of the L5-S1 segment of the same kinematics was also developed to compare the joint stresses predicted by the KD and SKD models. Matching well with in vivo data, the SKD model predicted a 15% and 33% reduction in contralateral muscle forces to the 95% debilitated LGPT and MFL muscles, respectively. In contrast, the contralateral muscle force enhancement to the debilitated MFL muscle in the KD model was in contradiction with in vivo data, implying that the KD model is incapable of correctly predicting the muscular disorders. However, the similarity of both models' predictions of intradiscal pressures and intervertebral discs' stresses, which matched well with in vivo data, does indicate the feasibility of the KD model to investigate trunk muscle weakness effects on spinal loads, which could offer additional tools for research in ergonomics. Nonetheless, SKD models can be employed for assessment of contralateral muscle impotence in spinal neuromuscular disorders.

Potential pathological mechanisms of L3 degenerative spondylolisthesis in lumbar spinal stenosis patients: A case-control study

BACKGROUND

Degenerative spondylolisthesis (DS) occurs mostly at L4. However, there are a small number of patients in whom it occurs only at L3. Accordingly, past reports elucidating the factors of DS have been primarily concerned with L4 DS, and few reports are available on DS at L3. The objective of this study was to compare the differences between lumbar spinal stenosis patients with or without L3 DS and to identify the possible pathological mechanisms of their L3 DS.

METHODS

Among the 369 patients with lumbar spinal stenosis who underwent lumbar surgery, we assessed 25 patients who had DS only at L3 and compared them against 50 other age- and gender-matched lumbar spinal stenosis patients without any DS. The following radiographic parameters: pelvic incidence, sacral slope, pelvic tilt, L3 slope, L4 slope, L5 slope, and lumbar lordosis were measured on radiographs. The orientation of facet joints and disc heights were measured via computed tomography.

RESULTS

Imaging findings showed that the L3, L4, and L5 slopes in the L3 DS group were significantly greater than in the non-DS group, and only L3/4 facet joints in the L3 DS group were significantly more sagittally oriented than in the control group. The number of patients with low disc heights at L4/5 in the L3 DS group was significantly greater than in the control group.

CONCLUSIONS

The results suggested that the greater lumbar slope, including L3 together with more sagittally oriented facet joints only at L3/4 and not at L4/5, may lead to DS only at L3.

Dependence of lumbar loads on spinopelvic sagittal alignment: An evaluation based on musculoskeletal modeling

Still little is known about how spinopelvic alignment affects spinal load distribution. Musculoskeletal modeling can potentially help to discover associations between spine alignment and risk factors of spinal disorders (e.g. disc herniation, vertebral fracture, spondylolisthesis, low back pain). The present study exploited the AnyBody full-body musculoskeletal model to assess the relation between lumbar loads and spinopelvic alignment in the sagittal plane. The model was evaluated in the standing position. The simulated postures were set using spinopelvic parameters gleaned from the literature and characterizing the healthy adult population. The parameters were: sagittal vertical axis, Roussouly lumbar type, sacral slope, and pelvic incidence. A total of 2772 configurations were simulated based on the following measurements: compression force and anterior shear at levels L4L5 and L5S1; multifidus, longissimus spinae, and rectus abdominis muscle forces. Changes in global sagittal alignment, lumbar typology, and sacral inclination, but not in pelvic incidence, were found to affect intervertebral loads in the lumbar spine and spinal muscle activation. Considering these changes would be advantageous for clinical evaluation, due to the recognized relation between altered loads and risk of disc herniation, vertebral fracture, spondylolisthesis, and low back pain. Musculoskeletal modeling proved to be a valuable biomechanical tool to non-invasively investigate the relation between internal loads and anatomical parameters.

Does improvement towards a normal cervical sagittal configuration aid in the management of cervical myofascial pain syndrome: a 1- year randomized controlled trial

Background

There is a growing interest concerning the understanding of and rehabilitation of the sagittal configuration of the cervical spine as a clinical outcome. However, the literature on the topic specific to conservative treatment outcomes of patients with chronic myofascial cervical pain syndrome (CMCPS) has not adequately addressed the relationship between cervical sagittal alignment and improved pain, disability and range of motion.

Methods

A randomized controlled study with a 1-year follow-up. Here, 120 (76 males) patients with chronic CMCPS and defined cervical sagittal posture abnormalities were randomly assigned to the control or an intervention group. Both groups received the Integrated neuromuscular inhibition technique (INIT); additionally, the intervention group received the denneroll cervical traction device. Alignment outcomes included two measures of sagittal posture: cervical angle (CV), and shoulder angle (SH). Patient relevant outcome measures included: neck pain intensity (NRS), neck disability (NDI), pressure pain thresholds (PPT), cervical range of motion using the CROM. Measures were assessed at three intervals: baseline, 10 weeks, and 1 year after the 10 week follow up.

Results

After 10 weeks of treatment, between group statistical analysis, showed equal improvements for both the intervention and control groups in NRS (p = 0.36) and NDI (p = 0.09). However, at 10 weeks, there were significant differences between groups favoring the intervention group for PPT (p<0.001) and all measures of CROM (p<0.001). Additionally, at 10 weeks the sagittal alignment variables showed significant differences favoring the intervention group for CV p<0.001 and SH (p<0.001) indicating improved CSA. Importantly, at the 1-year follow-up, between group analysis identified a regression back to baseline values for the control group for the non-significant group differences (NRS and NDI) at the 10-week mark. Thus, all variables were significantly different between groups favoring the intervention group at 1-year follow up: NRS (p<0.001), NDI (p<0.001), PPT p<0.001), CROM (p<0.001), CV (p<0.001), SH (p<0.001).

Conclusion

The addition of the denneroll cervical orthotic to a multimodal program positively affected CMCPS outcomes at long term follow up. We speculate the improved sagittal cervical posture alignment outcomes contributed to our findings.

Trial registration

Pan African Clinical Trial Registry Clinical Trial Registry: PACTR201801002968301, registered 11 January 2018 (retrospectively registered).

The pelvic radius technique in the assessment of spinopelvic sagittal alignment of degenerative spondylolisthesis and lumbar spinal stenosis

BACKGROUND

Degenerative spondylolisthesis (DS) and lumbar spinal stenosis (LSS) are the most common degenerative spinal diseases. The evaluating of spinopelvic sagittal alignment of the two diseases using pelvic radius (PR) technique have not been reported. The purpose of this study was to use PR measurement technique to compare the differences in spinopelvic sagittal alignment between DS and LSS.

METHODS

A total of 145 patients with DS or LSS were retrospectively reviewed. Seventy patients with DS (DS group) and 75 age-matched patients with LSS (LSS group) were enrolled. Spinopelvic parameters including pelvic angle (PA), regional lumbopelvic lordosis (PR-L1, PR-L2, PR-L3, PR-L4 and PR-L5), total lumbopelvic lordosis (PR-T12), pelvic morphology (PR-S1), sagittal vertical axis from the C7 plumb line (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), L4 slope and L5 slope were assessed in the two groups. Several parameters of DS and LSS group were compared with the normal population (NP).

RESULTS

The PR-L4, PR-L5 and PR-S1 in the DS group were significantly smaller than those in the LSS group. There was no difference in PR-T12 between the DS group and NP (p > 0.05), while PR-T12 of the LSS group were significantly lower (p < 0.01). Degree of correlations among spinopelvic parameters differed between the two groups. PR-T12 of the DS group was more strongly correlated with PA (r = -0.829, p < 0.001) than with LL (r = 0.664, p < 0.001), TK (r = 0.582, p < 0.001). PR-T12 of the LSS group was more strongly correlated with LL (r = 0.854, p < 0.001), TK (r = 0.616, p < 0.001) than with PA (r = -0.582, p < 0.001).

CONCLUSIONS

PR-L4 and PR-L5 may be the predisposing factors for DS development. Spinopelvic morphology differed in patients with DS and LSS compared to NP. The compensatory mechanisms to maintain spinopelvic sagittal alignment in DS and LSS patients may be different.

Adequate Restoration of Disc Height and Segmental Lordosis by Lumbar Interbody Fusion Decreases Adjacent Segment Degeneration

OBJECTIVE

This study aimed to investigate the effects of lumbar interbody fusion-induced biomechanical changes on the adjacent segments, especially disc height and segmental lordosis restoration, and to provide more information for proper surgical strategy selection.

METHODS

The medical records of 528 patients who underwent posterior lumbar interbody fusion were retrospectively reviewed, and a total of 89 patients were included. Surgical indications included degenerative spondylolisthesis (nonspondylolytic), marked disc herniation, or lumbar spinal stenosis requiring extensive decompression at L4/5. Postoperative adjacent segment degeneration (ASD) was assessed based on X-rays and functional status. Disc height, foraminal height, segmental lordosis, lumbar lordosis, and cage geometry were compared between the ASD and non-ASD patients. To identify the possible risk factors for radiographic ASD, univariate analysis was performed first, followed by multivariate logistic regression using variables with P < 0.20.

RESULTS

Univariate analysis revealed that the postoperative disc height in the non-ASD group were significantly greater than in the ASD group. The postoperative segmental lordosis in the non-ASD group was significantly greater than that in the ASD group, and the lumbar lordosis in the non-ASD group was also significantly greater than that in the ASD group at the final follow-up visit. Four variables were identified as independent risk factors for ASD by subsequent multivariate logistic regression: postoperative relative disc height of L4/5 (P = 0.011), postoperative segmental lordosis (P = 0.046), lumbar lordosis at the final follow-up visit (P = 0.007), and cage height (P = 0.038).

CONCLUSIONS

Improved lumbar lordosis is correlated with a lower incidence of ASD, and adequate disc height and segmental lordosis restoration are essential for ASD prevention.

Variation in lifting kinematics related to individual intrinsic lumbar curvature: an investigation in healthy adults

Objective

Lifting postures are frequently implicated in back pain. We previously related responses to a static load with intrinsic spine shape, and here we investigate the role of lumbar spine shape in lifting kinematics.

Methods

Thirty healthy adults (18-65 years) performed freestyle, stoop and squat lifts with a weighted box (6-15 kg, self-selected) while being recorded by Vicon motion capture. Internal spine shape was characterised using statistical shape modelling (SSM) from standing mid-sagittal MRIs. Associations were investigated between spine shapes quantified by SSM and peak flexion angles.

Results

Two SSM modes described variations in overall lumbar curvature (mode 1 (M1), 55% variance) and the evenness of curvature distribution (mode 2 (M2), 12% variance). M1 was associated with greater peak pelvis (r=0.38, p=0.04) and smaller knee flexion (r=-0.40, p=0.03) angles; individuals with greater curviness preferred to lift with a stooped lifting posture. This was confirmed by analysis of those individuals with very curvy or very straight spines (|M1|>1 SD). There were no associations between peak flexion angles and mode scores in stoop or squat trials (p>0.05). Peak flexion angles were positively correlated between freestyle and squat trials but not between freestyle and stoop or squat and stoop, indicating that individuals adjusted knee flexion while maintaining their preferred range of lumbar flexion and that 'squatters' adapted better to different techniques than 'stoopers'.

Conclusion

Spinal curvature affects preferred lifting styles, and individuals with curvier spines adapt more easily to different lifting techniques. Lifting tasks may need to be tailored to an individual's lumbar spine shape.

X-Ray Imaging is Essential for Contemporary Chiropractic and Manual Therapy Spinal Rehabilitation: Radiography Increases Benefits and Reduces Risks

To remedy spine-related problems, assessments of X-ray images are essential to determine the spine and postural parameters. Chiropractic/manual therapy realignment of the structure of the spine can address a wide range of pain, muscle weakness, and functional impairments. Alternate methods to assess such spine problems are often indirect and do not reveal the root cause and could result in a significant misdiagnosis, leading to inappropriate treatment and harmful consequences for the patient. Radiography reveals the true condition and alignment of the spine; it eliminates guesswork. Contemporary approaches to spinal rehabilitation, guided by accurate imaging, have demonstrated superiority over primitive treatments. Unfortunately, there are well-meaning but misguided activists who advocate elimination or minimization of exposures in spine radiography. The radiation dose employed for a plain radiograph is very low, about 100 times below the threshold dose for harmful effects. Rather than increasing risk, such exposures would likely stimulate the patient’s own protection systems and result in beneficial health effects. Spine care guidelines need to be revised to reflect the potential benefits of modern treatments and the lack of health risks from low X-ray doses. This would encourage routine use of radiography in manual spine therapy, which differs from common pharmacologic pain relief practice.

Comparison of Lumbosacral Alignment in Geriatric and Non-Geriatric patients suffering low back pain

Objective:

Lumbosacral alignment is a crucial factor for an appropriate spinal function. Changes in spinal alignment lead to diminished body biomechanics. Additionally, lumbosacral alignment may affect quality of life, sagittal balance and fall risk in elderly. In this study, we aimed to compare lumbosacral alignment in geriatric and non-geriatric patients suffering from low back pain.

Methods:

A total of 202 (120 male and 82 female) patients who visited to physical medicine and rehabilitation clinic with low back pain between January 2017 and August 2017 were enrolled in this study. Standing lateral lumbar radiographs were obtained from the electronic hospital database. Lumbar lordosis angle, sacral tilt, lumbosacral angle and lumbosacral disc angle were calculated on lateral standing lumbar radiographs.

Results:

The mean age of the non-geriatric group was 43.02 ± 13.20 years, the geriatric group was 71.61 ± 6.42 years. In geriatric patients, lumbar lordosis angle, sacral tilt and lumbosacral disc angle were significantly smaller (p = 0.042, p = 0.017 and p = 0.017). No significant differences were observed in lumbosacral angle between the groups (p = 0.508).

Conclusion:

Our study indicates the specific changes in lumbosacral alignment with aging. Identifying these changes in lumbosacral alignment in the geriatric population will enable to create proper rehabilitation strategies.

Correlation between lumbar intervertebral disc height and lumbar spine sagittal alignment among asymptomatic Asian young adults

BACKGROUND

To investigate the distribution and characteristics of the lumbar intervertebral disc height (IDH) in asymptomatic Asian population and to determine whether the lumbar IDH is related to the lumbar spine sagittal alignment.

METHODS

A cohort of 169 cases of asymptomatic volunteers was enrolled from January 2014 to July 2016. All participants underwent magnetic resonance imaging of the lumbar spine and panoramic radiography of the spine. Panoramic radiographs of the spine were taken to evaluate pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) using Surgimap® software. Roussouly classification was utilized to categorize all subjects according to the four subtypes of sagittal alignment. The IDH was measured on the MRI mid-saggital section of the vertebral body. The relationships between lumbar IDH and spine-pelvic parameters were also assessed using the Spearman correlation analysis.

RESULTS

The reference value ranges of IDH in asymptomatic Asian volunteers between L1/2, L2/3, L3/4, L4/5, and L5/S1 were (6.25, 10.99), (6.97, 12.08), (7.42, 13.3), (7.76, 14.57),and (7.11, 13.12) mm, respectively. Based on the above reference value, the high lumbar intervertebral space is defined as more than 14 mm. According to the Roussouly Classification, there are 33 cases in type I, 48 in type II, 66 in type III, and 22 in type IV. According to the definition of the high IDH, there are two cases in type I, three in type II, nine in type III, and eight in type IV. The results indicated that people in the Roussouly III and IV subtypes had greater values for IDH compared to those of Roussouly I and II subtypes, and the spinopelvic parameters were partly correlated with IDH in different subtypes. In addition, levels L4-L5 showed the highest IDH for all four groups followed by the L3-L4 and L5-S1 levels, and the value of L3-L4 is equivalent to that of L5-S1. All type groups showed moderate and positive correlations between the PI and IDH except the level of L1-L2 in type IV.

CONCLUSIONS

The IDH may influence the lumbar spine sagittal alignment in asymptomatic Asian adults. Moreover, pre-operative evaluation of IDH is useful for selection of optimal cage size and reconstruction of spinal alignment.

Thoracic hyperkyphosis non invasively measured by general practitioners is associated with chronic low back pain: A cross-sectional study of 1364 subjects

OBJECTIVE

The aim of this study was to examine the association between trunk sagittal posture and nonspecific chronic low back pain (CLBP) by evaluating plumb-line distances in subjects recruited in an everyday clinical setting.

METHODS

Of the 1364 subjects recruited, 63.1% were female (mean age ± SD: 56.2 ± 16.8 years). Subjects were categorized into CLBP and control groups and were prospectively assessed over a 3-month period. They provided information about their daily activities and their history of CLBP. Prognostic factors were analysed using univariate and multivariate logistic regression analyses. A physical examination was performed to record demographic (i.e. age, height and weight) and pain characteristics, and the intensity of pain was assessed using a numerical visual analogue scale. Disability was assessed using the Roland-Morris Disability Questionnaire (RMDQ). A simple measure generally used for sagittal plane screening purposes during growth was also utilized.

RESULTS

Multivariate logistic regression analysis revealed that gender (OR = 1.70), RMDQ score (OR = 0.51) and thoracic hyperkyphosis (C7 + L3 at the plumb-line distance) (OR = 1.57) were associated with CLBP. The final regression model explained 85.6% (R² = 0.56; P < 0.001) of the variability.

CONCLUSIONS

General practitioners can clinically and easily assess trunk posture in subjects with low back pain to identify subjects at higher risk of CLBP.

The role of cage height on the flexibility and load sharing of lumbar spine after lumbar interbody fusion with unilateral and bilateral instrumentation: a biomechanical study

BACKGROUND

One- and two-level lumbar interbody fusion with unilateral instrumentation is as effective as that with bilateral instrumentation. The height of the interbody cage influences the operated segment stability and the fusion technique success. The purpose of this research was to determine the effect of the fusion cage height (i.e. long and short) on both the stability (based on flexibility measures) and load sharing of the unilateral and bilateral instrumented transforaminal lumbar interbody fusion (TLIF) technique.

METHODS

The flexibility and load sharing tests were performed on seven human lumbar spines. Different configurations combining a long or short cage with a unilateral, bilateral, or no posterior fixation were used to stabilize the operated segment. Two sets of modular cages were designed for each type of test to simulate the long and short cages. During the flexibility test, a pure-moment load of 7.5 Nm was applied. The range of motion (ROM) was recorded for flexion-extension, lateral bending, and axial rotation. During the load sharing test, an axial-compression load of 400 N was applied. The load bearing of the cages was recorded using a cage-embedded load cell.

RESULTS

When the fusion cage height decreased 2 mm, the segment flexibility with unilateral fixation showed a significant increase in the ROM for flexion-extension, lateral bending, and axial rotation of 74.9, 83.8, and 175.2% (P < 0.01), respectively. In contrast, for bilateral fixation, the height decrease resulted in no significant change in ROM for flexion-extension (P = 0.686), lateral bending (P = 0.698), and axial rotation (P = 0.133). Using a short fusion cage, the load bearing decreased in 17.1, 21.5, and 54.1% (P < 0.05) for the cage alone, unilateral, and bilateral fixation, respectively.

CONCLUSIONS

A cage longer than the intervertebral space should be chosen to increase the stability and intervertebral graft load borne when performing TLIF with unilateral instrumentation.

Test-retest reliability and validity of a motion capture (MOCAP) system for measuring thoracic and lumbar spinal curvatures and sacral inclination in the sagittal plane

OBJECTIVE

To evaluate the test-retest reliability and validity of the MOCAP system for measuring spinal sagittal thoracic and lumbar curvatures and sacral inclination in a standing posture.

METHODS

Twenty-five male adults were evaluated on lateral standing radiographs. The thoracic and lumbar curvatures were calculated by Harrison's posterior tangent method. The sacral inclination was defined as the angle between the tangent line of the sacral and vertical plane. In addition, MOCAP was used to calculate the spinal curvatures and sacral inclination.

RESULTS

The thoracic and lumbar spine and sacral inclination demonstrated excellent reliability, with mean ICCs levels greater than 0.980 and low CVs (mean: 2.15%). Systematic biases were not significant and were very near 0, and the mean standard errors were 0.257∘. ANOVA of the radiographic and MOCAP measures did not report any statistically significant differences in the comparisons. The systematic biases and mean random errors were lower than 1∘, with CVs lower than 5% and mean ICCs higher than 0.90 between sessions.

CONCLUSION

The MOCAP system delivered consistently reliable and valid results for standing curvatures compared with a radiographic technique. This system could be used with confidence in research and clinical environments for sagittal spinal curvature measurements.

Incorporation of CT-based measurements of trunk anatomy into subject-specific musculoskeletal models of the spine influences vertebral loading predictions

We created subject-specific musculoskeletal models of the thoracolumbar spine by incorporating spine curvature and muscle morphology measurements from computed tomography (CT) scans to determine the degree to which vertebral compressive and shear loading estimates are sensitive to variations in trunk anatomy. We measured spine curvature and trunk muscle morphology using spine CT scans of 125 men, and then created four different thoracolumbar spine models for each person: (i) height and weight adjusted (Ht/Wt models); (ii) height, weight, and spine curvature adjusted (+C models); (iii) height, weight, and muscle morphology adjusted (+M models); and (iv) height, weight, spine curvature, and muscle morphology adjusted (+CM models). We determined vertebral compressive and shear loading at three regions of the spine (T8, T12, and L3) for four different activities. Vertebral compressive loads predicted by the subject-specific CT-based musculoskeletal models were between 54% lower to 45% higher from those estimated using musculoskeletal models adjusted only for subject height and weight. The impact of subject-specific information on vertebral loading estimates varied with the activity and spinal region. Vertebral loading estimates were more sensitive to incorporation of subject-specific spinal curvature than subject-specific muscle morphology. Our results indicate that individual variations in spine curvature and trunk muscle morphology can have a major impact on estimated vertebral compressive and shear loads, and thus should be accounted for when estimating subject-specific vertebral loading. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2164-2173, 2017.

A shared biomechanical environment for bone and posture development in children

BACKGROUND CONTEXT

In each specific habitual standing posture, gravitational forces determine the mechanical setting provided to skeletal structures. Bone quality and resistance to physical stress is highly determined by habitual mechanical stimulation. However, the relationship between bone properties and sagittal posture has never been studied in children.

PURPOSE

This study aimed to investigate the association between bone physical properties and sagittal standing postural patterns in 7-year-old children. We also analyzed the relationship between fat or fat-free mass and postural patterns.

STUDY DESIGN

Cross-sectional evaluation.

PATIENT SAMPLE

This study was performed in a sample of 1,138 girls and 1,260 boys at 7 years of age participating in the Generation XXI study, a population-based cohort of children followed since birth (2005-2006) and recruited in Porto, Portugal.

OUTCOME MEASURES

Sagittal standing posture was measured through photographs of the sagittal right view of children in the standing position. Three angles were considered to quantify the magnitude of major curves of the spine and an overall balance measure (trunk, lumbar, and sway angles). Postural patterns were identified using latent profile analysis in Mplus.

METHODS

Weight and height were measured. Total body less head fat or fat-free mass and bone properties were estimated from whole-body dual-energy X-ray absorptiometry scans. The associations of fat or fat-free mass and bone physical properties with postural patterns were jointly estimated in latent profile analysis using multinomial logistic regressions.

RESULTS

The identified patterns were labeled as Sway, Flat, and "Neutral to Hyperlordotic" (in girls), and "Sway to Neutral," Flat, and Hyperlordotic (in boys). In both genders, children in the Flat pattern showed the lowest body mass index, and children with a rounded posture presented the highest: mean differences varying from -0.86 kg/m² to 0.60 kg/m² in girls and from -0.70 kg/m² to 0.62 kg/m² in boys (vs. Sway or "Sway to Neutral"). Fat and fat-free mass were inversely associated with a Flat pattern and positively associated with a rounded posture: odds ratio (OR) of 0.23 per standard deviation (SD) fat and 0.70 per SD fat-free mass for the Flat pattern, and 1.85 (fat) and 1.43 (fat-free) for the Hyperlordotic pattern in boys, with similar findings in girls. The same direction of relationships was observed between bone physical properties and postural patterns. A positive association between bone (especially bone mineral density) and a rounded posture was robust to adjustment for age, height, and body composition (girls: OR=1.79, p=.006 fat-adjusted, OR=2.00, p=.014 fat-free mass adjusted; boys: OR=2.02, p=.002 fat-adjusted, OR=2.42, p<.001 fat-free mass adjusted).

CONCLUSIONS

In this population-based pediatric setting, there was an inverse association between bone physical properties and a Flat posture. Bone and posture were more strongly positively linked in a rounded posture. Our results support that both bone properties and posture mature in a shared and interrelated mechanical environment, probably modulated by pattern-specific anthropometrics and body composition.

Treating 'slouchy' (hyperkyphosis) posture with chiropractic biophysics®: a case report utilizing a multimodal mirror image® rehabilitation program

[Purpose] To present a case of the non-surgical reduction of ‘slouchy’ hyperkyphosis posture utilizing the multimodal Chiropractic BioPhysics^® rehabilitation program emphasizing the mirror image^® concept. [Subject and Methods] A 27-year-old female presented suffering from neck and back pains, headaches and gait dysfunction. The patient was treated 30 times over a period of 6-months. Treatment consisted of anterior thoracic translation, thoracic extension, and head retraction exercises as well as spinal traction and spinal manipulation. [Results] After 6-months of treatment the patient displayed a total correction of the posterior thoracic translation with a significant reduction in thoracic hyperkyphosis. The dramatic correction of her overall posture and spine alignment corresponded to the significant relief of neck and back pains, headaches and improvement of various other health issues as demonstrated by self-report and SF-36. [Conclusion] Poor postures corresponding to poor health can be changed for the better with multimodal rehabilitation programs that are now showing consistent postural improvements corresponding with improvements in various health conditions. We suggest that the postural correction of those with various pain symptoms be considered as a first line non-pharmalogical, non-surgical rehabilitation approach for those presenting with poor posture.

The relationships between low back pain and lumbar lordosis: a systematic review and meta-analysis

BACKGROUND CONTEXT

Clinicians regard lumbar lordotic curvature (LLC) with respect to low back pain (LBP) in a contradictory fashion. The time-honored point of view is that LLC itself, or its increment, causes LBP. On the other hand, recently, the biomechanical role of LLC has been emphasized, and loss of lordosis is considered a possible cause of LBP. The relationship between LLC and LBP has immense clinical significance, because it serves as the basis of therapeutic exercises for treating and preventing LBP.

PURPOSE

This study aimed to (1) determine the difference in LLC in those with and without LBP and (2) investigate confounding factors that might affect the association between LLC and LBP.

STUDY DESIGN

Systematic review and meta-analysis.

PATIENT SAMPLE

The inclusion criteria consisted of observational studies that included information on lumbar lordotic angle (LLA) assessed by radiological image, in both patients with LBP and healthy controls. Studies solely involving pediatric populations, or addressing spinal conditions of nondegenerative causes, were excluded.

METHODS

A systematic electronic search of Medline, Embase, Cochrane Library, CINAHL, Scopus, PEDro, and Web of Science using terms related to lumbar alignment and Boolean logic was performed: (lumbar lordo*) or (lumbar alignment) or (sagittal alignment) or (sagittal balance). Standardized mean differences (SMD) and 95% confidence intervals (CI) were estimated, and chi-square and I² statistics were used to assess within-group heterogeneity by random effects model. Additionally, the age and gender of participants, spinal disease entity, and the severity and duration of LBP were evaluated as possible confounding factors.

RESULTS

A total of 13 studies consisting of 796 patients with LBP and 927 healthy controls were identified. Overall, patients with LBP tended to have smaller LLA than healthy controls. However, the studies were heterogeneous. In the meta-regression analysis, the factors of age, severity of LBP, and spinal disease entity were revealed to contribute significantly to variance between studies. In the subgroup analysis of the five studies that compared patients with disc herniation or degeneration with healthy controls, patients with LBP had smaller LLA (SMD: -0.94, 95% CI: -1.19 to -0.69), with sufficient homogeneity based on significance level of .1 (I²=45.7%, p=.118). In the six age-matched studies, patients with LBP had smaller LLA than healthy controls (SMD: -0.33, 95% CI: -0.46 to -0.21), without statistical heterogeneity (I²=0%, p=.916).

CONCLUSIONS

This meta-analysis demonstrates a strong relationship between LBP and decreased LLC, especially when compared with age-matched healthy controls. Among specific diseases, LBP by disc herniation or degeneration was shown to be substantially associated with the loss of LLC.

Test-retest reliability and validity of a motion capture (MOCAP) system for measuring thoracic and lumbar spinal curvatures and sacral inclination in the sagittal plane

OBJECTIVE

To evaluate the test-retest reliability and validity of the MOCAP system for measuring spinal sagittal thoracic and lumbar curvatures and sacral inclination in a standing posture.

METHODS

Twenty-five male adults were evaluated on lateral standing radiographs. The thoracic and lumbar curvatures were calculated by Harrison's posterior tangent method. The sacral inclination was defined as the angle between the tangent line of the sacral and vertical plane. In addition, MOCAP was used to calculate the spinal curvatures and sacral inclination.

RESULTS

The thoracic and lumbar spine and sacral inclination demonstrated excellent reliability, with mean ICCs levels greater than 0.980 and low CVs (mean: 2.15%). Systematic biases were not significant and were very near 0, and the mean standard errors were 0.257∘. ANOVA of the radiographic and MOCAP measures did not report any statistically significant differences in the comparisons. The systematic biases and mean random errors were lower than 1∘, with CVs lower than 5% and mean ICCs higher than 0.90 between sessions.

CONCLUSION

The MOCAP system delivered consistently reliable and valid results for standing curvatures compared with a radiographic technique. This system could be used with confidence in research and clinical environments for sagittal spinal curvature measurements.

Spinal Loading Patterns From Biomechanical Modeling Explain the High Incidence of Vertebral Fractures in the Thoracolumbar Region

Vertebral fractures occur most frequently in the mid-thoracic and thoracolumbar regions of the spine, yet the reasons for this site-specific occurrence are not known. Our working hypothesis is that the locations of vertebral fracture may be explained by the pattern of spine loading, such that during daily activities the mid-thoracic and thoracolumbar regions experience preferentially higher mechanical loading compared to other spine regions. To test this hypothesis, we used a female musculoskeletal model of the full thoracolumbar spine and rib cage to estimate the variation in vertebral compressive loads and associated factor-of-risk (load-to-strength ratio) throughout the spine for 119 activities of daily living, while also parametrically varying spine curvature (high, average, low, and zero thoracic kyphosis models). We found that nearly all activities produced loading peaks in the thoracolumbar and lower lumbar regions of the spine, but that the highest factor-of-risk values generally occurred in the thoracolumbar region of the spine because these vertebrae had lower compressive strength than vertebrae in the lumbar spine. The peaks in compressive loading and factor-of-risk in the thoracolumbar region were accentuated by increasing thoracic kyphosis. Activation of the multifidus muscle fascicles selectively in the thoracolumbar region appeared to be the main contributor to the relatively high vertebral compressive loading in the thoracolumbar spine. In summary, by using advanced musculoskeletal modeling to estimate vertebral loading throughout the spine, this study provides a biomechanical mechanism for the higher incidence of fractures in thoracolumbar vertebrae compared to other spinal regions. © 2017 American Society for Bone and Mineral Research.