Sagittal balance parameters correlate with spinal conformational type and MRI changes in lumbar degenerative disc disease: results of a retrospective study

Lumbar paraspinal muscle morphology is associated with spinal degeneration in patients with lumbar spinal stenosis

BACKGROUND CONTEXT

Lumbar spinal stenosis (LSS) has been reported to induce changes in paraspinal muscle morphology, but objective physical function and degenerative spine conditions are rarely assessed.

PURPOSE

To identify factors associated with paraspinal muscle morphology using objective physical and degenerative spine assessments in patients with LSS.

STUDY DESIGN/SETTING

Cross-sectional design.

PATIENT SAMPLE

Seventy patients with neurogenic claudication caused by LSS, receiving outpatient physical therapy.

OUTCOME MEASURES

Cross-sectional area (CSA) and functional CSA (FCSA) of the multifidus, erector spinae, and psoas muscles, the severity of stenosis, disc degeneration, and endplate abnormalities were evaluated by magnetic resonance imaging, as well as sagittal spinopelvic alignment by X-ray. Objective physical assessments included pedometry and claudication distance. Patient-reported outcomes included the numerical rating scale of low back pain, leg pain, and leg numbness, and the Zurich Claudication Questionnaire.

METHODS

To assess the impact of LSS on paraspinal muscles, FCSA and FCSA/CSA were compared between the dominant and nondominant sides based on the patients' neurogenic symptoms, and multivariable regression analyses adjusted for age, sex, height, and weight were performed; p<.05 was considered significant.

RESULTS

Seventy patients were analyzed. At one level below the maximum stenotic level, erector spinae FCSA on the dominant side was significantly lower than that on the nondominant side. In the multivariable regression analyses, at one level below the symptomatic level, disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment, such as decreased lumbar lordosis and increased pelvic tilt, were negatively associated with multifidus FCSA and FCSA/CSA ratio. A significant association was observed between dural sac CSA and erector spinae FCSA. Throughout L1/2 to L5/S, disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment were negatively associated with multifidus and erector spinae FCSA or FCSA/CSA.

CONCLUSIONS

Lumbar paraspinal muscle asymmetry caused by LSS was observed only in erector spinae. Disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment, rather than spinal stenosis and LSS symptoms, were more associated with paraspinal muscle atrophy or fat infiltration.

Biomechanical Effects of Different Sitting Postures and Physiologic Movements on the Lumbar Spine: A Finite Element Study

This study used the finite element method(FEM) to investigate how pressure on the lumbar spine changes during dynamic movements in different postures: standing, erect sitting on a chair, slumped sitting on a chair, and sitting on the floor. Three load modes (flexion, lateral bending, and axial rotation) were applied to the FEM, simulating movements of the lumbar spine. Results showed no significant difference in pressure distribution on the annulus fiber and nucleus pulposus, representing intradiscal pressure, as well as on the cortical bone during movements between standing and erect sitting postures. However, both slumped sitting on a chair and sitting on the floor postures significantly increased pressure on the nucleus pulposus, annulus fibrosus, and cortical bone in all three movements when compared to standing or erect sitting on a chair. Notably, sitting on the floor resulted in even higher pressure on the nucleus pulposus and annulus fibers compared to slumped sitting on a chair. The decreased lumbar lordosis while sitting on the floor led to the highest increase in pressure on the annulus fiber and nucleus pulposus in the lumbar spine. In conclusion, maintaining an erect sitting position with increased lumbar lordosis during seated activities can effectively reduce intradiscal pressure and cortical bone stress associated with degenerative disc diseases and spinal deformities.

Patient-related risk factors and lifestyle factors for lumbar degenerative disc disease: a systematic review

OBJECTIVE

Back pain is a very widespread disease pattern and is one of the most frequent causes for consultation of a physician in general. In most cases, discogenic changes are the pathomorphological correlate of back pain. Numerous risk factors have been identified for these degenerative changes, but the influence and significance of the risk factors remain unclear, which was the aim of this systematic review.

METHODS

A systematic literature search of the commonly used Pubmed database was performed using specific MESH terms. Further selection of the included studies was performed according to the PRISMA scheme, taking into account scientific merit as well as the relation to the research question.

RESULTS

A total of 111 studies out of 1035 found were finally included in the literature search. 134 risk factors for disc degeneration and disc herniation were identified. These were divided into (1) patient-specific risk factors (n░=░34), (2) radiological risk factors (n░=░31), (3) lifestyle risk factors (n░=░6), (4) workplace-related risk factors (n░=░12), (5) genetic risk factors (n░=░50), and (6) other risk factors (n░=░1). Non-adjustable risk factors were age >50 years (OR 1.7/year), female gender (OR 1.41), family disposition (OR 4.0), comorbidities like atherosclerosis (OR 2.24), arthritic changes in other joints (OR 3.1) and history of injuries of the back (OR 3.1). Adjustable factors were elevated BMI (OR 2.77), comorbidities like hypertension (OR 1.25), dyslipidemia (OR 1.26) and diabetes mellitus (OR 6.8), as well as lifestyle habits like smoking (OR 3.8).

DISCUSSION

In summary, intervertebral disc degenerations and herniations represent multifactorial events whose risk factors can be partly influenced and partly not influenced. This systematic review highlights the current state of knowledge as a basis for creating patient-specific algorithms to calculate risk for the development or progression of degenerative disc changes and disc herniations.

Elucidation of effect of spinopelvic parameters in degenerative disc disease

INTRODUCTION

This study aims to find out if there is any relationship between disc pathology and spinopelvic morphology, respectively.

METHODS

A total of 152 patients who complained about low back pain were assessed retrospectively. Patients were divided into three groups based on the presence of disc pathology: non-degenerative (ND) (n=34), degenerative disc disease (DDD) (n=80), and lumbar disc herniation (LDH) (n=38). Spinopelvic parameters were measured on the lateral standing radiographs using Surgimap® Software. The degree of degeneration of each disc was evaluated using T2-weighted images according to the Pfirmann classification. Correlation analyses were performed.

RESULTS

No significant difference was observed between the three groups in terms of sagittal spinal and pelvic parameters. Age and BMI were positively correlated with DDD and LDH. PI and proximal lombar lordosis (PLL) were the only effective variables in predicting DDD. PT and distal lumbar lordosis (DLL) were found to be effective variables in predicting LDH. PI and PT values in patients with L1, L2, and L3 DDD were statistically significantly higher than those without degeneration (P<0.05). Although there were no statistical differences between PI and PT values (P>0.05), DLL values in L4 and L5 DDD patients were significantly lower than those without degeneration (P=0.041; P=0.046; P<0.05).

CONCLUSIONS

The sagittal morphology of the spine directly influences the extent of lumbar disc degeneration. As the values of PI and PT increase, disc degeneration tends to occur at higher levels (L1-2-3). Disc degeneration at lower levels (L4-5) was associated with low DLL levels.

LEVEL OF EVIDENCE

Level III, retrospective study.

Cohort study on the relationship between morphologic parameters of paravertebral muscles, BMI and lumbar lordosis on the severity of lumbar stenosis

INTRODUCTION

There is a growing body of literature separately linking lumbar spinal stenosis (LSS) with various factors such as paravertebral muscle (PVM) impaired function/morphology, lordosis or BMI. However, their interplay is yet to be known. The present study aims to investigate the relationship between PVM morphology, BMI and lumbar lordosis in a population with a surgical indication for LSS.

MATERIALS AND METHODS

A cross-sectional retrospective study was conducted on a group of 122 patients diagnosed with LSS in a hospital setting and scheduled for spine surgery. Epidemiological data and body mass index (BMI) were gathered. The cross-sectional area of the psoas muscle (rCSA) at the L4-L5 disc level on preoperative axial T2 MRI was measured. Fat infiltration of the anterior (APVM) and posterior paravertebral muscles (PPVM) was evaluated according to Goutallier classification while the severity of lumbar stenosis was staged according to Schizas criteria. Lumbar lordosis was measured on sagittal MRI using Cobb's angle method. The presence of the "rising psoas" sign was also noted. Statistical analysis of the data was performed using Pearson and Spearman correlations.

RESULTS

Statistical analysis revealed a moderate correlation between the severity of LSS and BMI (p = 0.001), and fatty infiltration of paravertebral muscles (p = 0.000, p = 0.000). Adjusting for age, gender, and BMI resulted in a low correlation (p = 0.003, p = 0.045), rCSA correlated negatively with age, gender, and lordosis. BMI had a low positive correlation with lumbar lordosis (p = 0.006), severity (p = 0.001), number of levels (p = 0.005) and PPVM (p = 0.031).

CONCLUSIONS

This study highlighted the relationship between PVM morphology and the severity of radiological signs in patients with LSS undergoing spine surgery and found a correlation independent of age, gender, and BMI. BMI was also shown to correlate with the severity after controlling for age and gender. rCSA has limited use in evaluating the severity of LSS.

Avaliação da confiabilidade e reprodutibilidade da classificação de Roussouly para os tipos de lordose lombar

Objective  The present study aims to determine the intra- and inter-rater reliability and reproducibility of the Roussouly classification for lumbar lordosis types.

Methods  A database of 104 panoramic, lateral radiographs of the spine of male individuals aged between 18 and 40 years old was used. Six examiners with different expertise levels measured spinopelvic angles and classified lordosis types according to the Roussouly classification using the Surgimap software (Nemaris Inc., New York, NY, USA). After a 1-month interval, the measurements were repeated, and the intra- and inter-rater agreement were calculated using the Fleiss Kappa test.

Results  The study revealed positive evidence regarding the reproducibility of the Roussouly classification, with reasonable to virtually perfect (0.307–0.827) intra-rater agreement, and moderate (0.43) to reasonable (0.369) inter-rater agreement according to the Fleiss kappa test. The most experienced examiners showed greater inter-rater agreement, ranging from substantial (0.619) to moderate (0.439).

Conclusion  The Roussouly classification demonstrated good reliability and reproducibility, with intra- and inter-rater agreements at least reasonable, and reaching substantial to virtually perfect levels in some situations. Evaluators with highest expertise levels showed greater intra and inter-rater agreement.

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.

Analgesic Posture and Pelvic Morphology in Patients with Lumbar Disc Herniation

OBJECTIVE

Pelvic morphology is an important element in determination of spinal alignment. We retrospectively examined the correlation between spinal alignment, severity, and pelvic morphology in lumbar disc herniation (LDH) surgery.

METHODS

The study included 62 cases of paramedian LDH surgeries (L4-5: 19 cases; L5-S1: 43 cases). For all cases, we performed x-ray imaging of the whole spine in the standing position preoperatively and 1 week postoperatively and measured spinopelvic parameters. Comparing preoperative parameters of patients with 82 healthy subjects, we examined changes before and after surgery. We also examined the relationship between preoperative severity and parameters.

RESULTS

Compared with healthy subjects, patients with LDH exhibited significantly decreased lumbar lordosis and sacral slope and increased pelvic tilt and sagittal vertical axis (P < 0.01). Japanese Orthopaedic Association score improved from 16.1 ± 4.6 preoperatively to 23.5 ± 3.2 1 week postoperatively (P < 0.01). Spinopelvic parameters observed preoperatively improved significantly 1 week postoperatively (P < 0.01). Correlation analysis did not confirm any correlation of severity with preoperative pelvic tilt, sagittal vertical axis, or pelvic incidence. However, cases with high pelvic tilt/pelvic incidence were significantly more likely to be severe cases (R² = 0.08, P = 0.027). A significant decrease in pelvic tilt was observed in cases with a large improvement in postoperative Japanese Orthopaedic Association score (P = 0.031).

CONCLUSIONS

For LDH cases, pelvic retroversion is important to avoid pain. The range of mobility for pelvic retroversion varies depending on pelvic morphology of individuals. In cases of LDH, ratio of pelvic tilt to pelvic incidence correlates strongly with severity.

Reduction of spondylolisthesis and sagittal balance correction by anterior lumbar interbody fusion (ALIF)

PURPOSE

Long time recognized as a cause of lumbar stenosis, degenerative spondylolisthesis has an evolution in interrelation with sagittal balance. This study aimed to assess the role of ALIF in correcting the sagittal balance in patients with degenerative spondylolisthesis.

MATERIAL AND METHODS

Twenty patients aged between 47 and 70 years were operated between July 2011 and September 2014 for degenerative spondylolisthesis by ALIF. The pre-operative and post-operative valid standing full spine radiographs were reviewed retrospectively. Clinical and radiological evaluations were conducted pre-operatively and postoperatively at one year and five years.

RESULTS

Lumbar lordosis (LL) was measured to 41.16 ± 14.25° pre-operatively and 47.27 ± 11.25° post-operatively (p > 0.05). At one year was 49.76 ± 13.31° and at five years 46.93 ± 9.26° (p > 0.05). Mean gain of lordosis after ALIF at index level was calculated to 8 ± 1.6° [4-12°].

CONCLUSIONS

ALIF offers a good reduction of the slipped vertebra providing good conditions for fusion and is an efficient surgical technique to recreate the sagittal spine balance.

Lumbar degenerative disease after oblique lateral interbody fusion: sagittal spinopelvic alignment and its impact on low back pain

Background

We determined the incidence and risk factors of low back pain (LBP) in patients with lumbar degenerative disease after single-level oblique lateral interbody fusion (OLIF).

Methods

We retrospectively reviewed 120 lumbar degenerative disease patients who underwent single-level OLIF. We compared preoperative and postoperative radiographic parameters, including segmental lordosis (SL), lumbar lordosis (LL), disk height (DH), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), and C7-sagittal vertical axis (SVA). Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) scores and visual analog scale (VAS) scores for back and leg pain. All patients were followed up for at least 2 years.

Results

Thirty-eight patients had postoperative LBP (VAS score for back pain ≥3; LBP group); the remaining 82 patients were in the non-LBP group. Age (P = 0.082), gender (P = 0.425), body mass index (P = 0.138), diagnosis (degenerative spondylolisthesis vs. lumbar spinal stenosis; P = 0.529), surgical level (P = 0.651), blood loss (P = 0.889), and operative time (P = 0.731) did not differ between the groups. In both groups, the ODI and VAS scores for back pain and leg pain significantly improved at the final follow-up compared with the preoperative scores (P = 0.003). Except for the VAS score for back pain (P = 0.000), none of the scores significantly differed between the two groups at the final follow-up (P > 0.05). In the non-LBP group, LL, SL, DH, TK, and SS significantly improved, while PT and C7-SVA significantly decreased at the final follow-up as compared with the preoperative values. In both groups, DH significantly improved postoperatively, with no significant between-group difference (P = 0.325). At the final follow-up, LL, PI-LL mismatch, PT, and C7-SVA showed significantly greater improvement in the non-LBP group than in the LBP group (P < 0.05). Multivariate analysis identified PT, PI-LL mismatch, and C7-SVA as significant risk factors for LBP after OLIF.

Conclusion

OLIF for single-level lumbar degenerative disease had satisfactory clinical outcomes. PT, PI-LL mismatch, and C7-SVA were significant risk factors for postoperative LBP. Patients with appropriately decreased PT, improved C7-SVA, and PI-LL match experienced less LBP.

Spinopelvic sagittal balance: what does the radiologist need to know?

Sagittal balance describes the optimal alignment of the spine in the sagittal plane, resulting from the interaction between the spine and lower limbs, via the pelvis. Understanding sagittal balance has gained importance, especially in the last decade, because sagittal imbalance correlates directly with disability and pain. Diseases that alter that balance cause sagittal malalignment and may trigger compensatory mechanisms. Certain radiographic parameters have been shown to be clinically relevant and to correlate with clinical scores in the evaluation of spinopelvic alignment. This article aims to provide a comprehensive review of the literature on the spinopelvic parameters that are most relevant in clinical practice, as well as to describe compensatory mechanisms of the pelvis and lower limbs.