Factors predicting progression in early degenerative lumbar scoliosis

Sex-based differences in clinical and radiological presentation of patients with degenerative lumbar scoliosis: a cross-sectional study

BACKGROUND

To evaluate the sex-based differences in clinical and radiological presentation of patients with degenerative lumbar scoliosis (DLS) and to explore whether the difference is helpful in investigating the etiology and progression of DLS.

METHOD

A retrospective review of 199 patients (41 males, 158 females) with DLS was included. Patient demographics including age, gender, bone mineral density were collected. Back and leg pain was assessed by visual analog scale, and general physical condition was assessed by Oswestry Disability Index. Cobb's angle was measured, and direction of scoliosis, position of the superior, inferior and apex vertebrae, number of vertebrae included in the scoliosis, rotation of apex vertebrae (Nash-Mo index), translation of apex vertebrae were recorded. Sagittal longitudinal axis, thoracolumbar kyphosis, lumbar lordosis (LL), pelvic incidence angle (PI), sacral slope, apex of lumbar lordosis and coronal balance distance were measured by whole spine lateral radiographs, and type of coronal imbalance was evaluated in all patients. Fat infiltration rate (FIR) of the paraspinal muscles at the vertebral apex was measured by MRI.

RESULT

Compared to female patients, male patients showed more back and leg pain on clinical presentation and smaller Cobb angle, less parietal rotation, larger LL, smaller PI-LL and lower paravertebral muscle FIR on radiologic features.

CONCLUSION

Gender differences do exist in DLS patients with regard to clinical and radiological presentation, low back pain was more pronounced in male patients, and scoliosis was more severe in female patients based on this cross-sectional study.

Loss of CSF-contacting neuron sensory function is associated with a hyper-kyphosis of the spine reminiscent of Scheuermann's disease

Scheuermann's disease, also referred to as Scheuermann's kyphosis, is the second most frequent spine deformity occurring in humans after adolescent idiopathic scoliosis (AIS), both with an unclear etiology. Recent genetic studies in zebrafish unraveled new mechanisms linked to AIS, highlighting the role of the Reissner fiber, an acellular polymer bathing in the cerebrospinal fluid (CSF) in close proximity with ciliated cells and mechanosensory neurons lining the central canal of the spinal cord (CSF-cNs). However, while the Reissner fiber and ciliary beating have been linked to AIS-like phenotypes in zebrafish, the relevance of the sensory functions of CSF-cNs for human spine disorders remains unknown. Here, we show that the thoracic hyper-kyphosis of the spine previously reported in adult pkd2l1 mutant zebrafish, in which the mechanosensory function of CSF-cNs is likely defective, is restricted to the sagittal plane and is not associated with vertebral malformations. By applying orthopedic criteria to analyze the amplitude of the curvature at the apex of the kyphosis, the curve pattern, the sagittal balance and sex bias, we demonstrate that pkd2l1 knock-outs develop a phenotype reminiscent of Scheuermann's disease. Altogether our work consolidates the benefit of combining genetics and analysis of spine deformities in zebrafish to model idiopathic spine disorders in humans.

Decompression Alone in the Setting of Adult Degenerative Lumbar Scoliosis and Stenosis: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and meta-analysis.OBJECTIVESSurgical decompression alone for patients with neurogenic leg pain in the setting of degenerative lumbar scoliosis (DLS) and stenosis is commonly performed, however, there is no summary of evidence for outcomes.

METHODS

A systematic search of English language medical literature databases was performed for studies describing outcomes of decompression alone in DLS, defined as Cobb angle >10˚, and 2-year minimum follow-up. Three outcomes were examined: 1) Cobb angle progression, 2) reoperation rate, and 3) ODI and overall satisfaction. Data were pooled and weighted averages were calculated to summarize available evidence.

RESULTS

Across 15 studies included in the final analysis, 586 patients were examined. Average preoperative and postoperative Cobb angles were 17.6˚ (Range: 12.7 - 25˚) and 18.0 (range 14.1 - 25˚), respectively. Average change in Cobb angle was an increase of 1.8˚. Overall rate of reoperation ranged from 3 to 33% with an average of 9.7%. Average ODI before surgery, after surgery, and change in scores were 56.4%, 27.2%, and an improvement of 29% respectively. Average from 8 studies that reported patient satisfaction was 71.2%.

CONCLUSIONS

Current literature on decompression alone in the setting of DLS is sparse and is not high quality, limited to patients with small magnitude of lumbar coronal Cobb angle, and heterogenous in the type of procedure performed. Based on available evidence, select patients with DLS who undergo decompression alone had minimal progression of Cobb angle, relatively low reoperation rate, and favorable patient-reported outcomes.

Genetic and serum markers in adult degenerative scoliosis: a literature review

STUDY DESIGN

Literature review.

OBJECTIVE

Adult degenerative scoliosis (ADS) is becoming a more prevalent diagnosis with an increasing elderly population. Our objective is to provide a literature review of genetic and serum markers in ADS.

METHODS

A literature review was conducted in the various databases from their inception to July 2020. Studies that reviewed any genetic or serum markers of ADS whether in detection or progression were selected. Studies that reviewed congenital scoliosis or adolescent idiopathic scoliosis (AIS) were excluded.

RESULTS

A total of 1447 titles were identified of which 14 were included in the final review. Two papers reported on serum markers pertaining to serum cartilage metabolites and pentosidine. Twelve studies reported on genetic markers including gene polymorphisms in estrogen receptors, parathyroid hormone receptors, interleukin 6, cyclooxygenase-2 (COX-2), COL2A1, GPRIN1, TRAIL, GRIN receptor, RIMS, LBX1 as well as copy number variations.

CONCLUSIONS

Serum markers of osteoarthritis and sarcopenia have been found to be significantly elevated in ADS patients as well. Numerous polymorphisms have been found in a variety of genes playing key roles in bone formation and regulation. Further research is needed in validating previous studies as well as identifying other biomarkers for patients at risk for developing ADS.

Radiologic prognostic factors of curve progression in early degenerative lumbar scoliosis

OBJECTIVE

Several radiological parameters related to the aging spine have been reported as progression factors of early degenerative lumbar scoliosis (DLS). However, it has not been determined which factors are the most important. In this study the authors aimed to determine the risk factors associated with curve progression in early DLS.

METHODS

Fifty-one patients with early DLS and Cobb angles of 5°-15° were investigated. In total, 7 men and 44 women (mean age 61.6 years) were observed for a mean period of 13.7 years. The subjects were divided into two groups according to Cobb angle progression (≥ 15° or < 15°) at the final follow-up, and radiological parameters were compared. The direction of scoliosis, apical vertebral level and rotational grade, lateral subluxation, disc space difference, osteophyte difference, upper and lower disc wedging angles, and relationship between the intercrest line and L5 vertebra were evaluated.

RESULTS

During the follow-up period, the mean curve progression increased from 8.8° ± 3.2° to 19.4° ± 8.9°. The Cobb angle had progressed by ≥ 15° in 17 patients (33.3%) at the final follow-up. In these patients the mean Cobb angle increased from 9.4° ± 3.4° to 28.8° ± 7.5°, and in the 34 remaining patients it increased from 8.5° ± 3.1° to 14.7° ± 4.8°. The baseline lateral subluxation, disc space difference, and upper and lower disc wedging angles significantly differed between the groups. In multivariate logistic regression analysis, only the upper and lower disc wedging angles were significantly correlated with curve progression (OR 1.55, p = 0.035, and OR 1.89, p = 0.004, respectively).

CONCLUSIONS

Asymmetrical degenerative change in the lower apical vertebral disc, which leads to upper and lower disc wedging angles, is the most substantial factor in predicting early DLS progression.

Passive stiffness characteristics and neutral zone quality of the scoliotic lumbar torso in the principle anatomical planes of motion

BACKGROUND

The 1-10% prevalence rate of adult scoliosis frequently requires expensive therapy and surgical treatments and demands further research into the disease, especially with an aging population. Most studies examining the mechanics of scoliosis have focused on in vitro testing or computer simulations. This study quantitatively defined the passive stiffness properties of the in vivo scoliotic spine in three principle anatomical motions and identified differences relative to healthy controls.

METHODS

Adult scoliosis (n = 14) and control (n = 17) participants with no history of spondylolisthesis, spinal fracture, or spinal surgery participated in three different tests (torso lateral side bending, torso axial rotation, and torso flexion/extension) that isolated mobility to the in vivo lumbar spine. The spinal stiffnesses and spinal neutral zone width were calculated. These parameters were statistically compared between factor of population and within factor of direction.

FINDINGS

Torque-rotational displacement data were fit using a double sigmoid function, resulting an in excellent overall fit (Avg. R² = 0.95). There was a significant interaction effect between populations when comparing axial twist neutral zone width vs. lateral bend neutral zone width and axial twist stiffness vs. lateral bend stiffness. The axial twist neutral zone width magnitude was significantly larger in scoliosis patients.

INTERPRETATION

The present study is the first investigation to quantify the whole trunk neutral zone of the scoliotic lumbar spine. Future research is needed to determine if lumbar spine mechanical characteristics can help explain progression of scoliosis and complement scoliosis classification systems.

Hounsfield Unit for Assessing Vertebral Bone Quality and Asymmetrical Vertebral Degeneration in Degenerative Lumbar Scoliosis

STUDY DESIGN

Retrospective analysis.

OBJECTIVES

The aim of this study was to demonstrate the correlation between degenerative lumbar scoliosis (DLS) and osteoporosis based on Hounsfield unit (HU) measurement from computed tomography (CT) scans, and to investigate the asymmetrical vertebral degeneration in DLS.

SUMMARY OF BACKGROUND DATA

The correlation between DLS and osteoporosis measured by dual-energy x-ray absorptiometry (DEXA) is debated, since T-scores measured by DEXA scan can be overestimated due to abdominal vessel wall calcification, degenerative bony spurs, and facet hypertrophy. The reliability and accuracy of HU to determine osteoporosis are shown in many reports, but it has never been used to assess the vertebral bone quality for DLS patients.

METHODS

Nighty-five DLS patients were retrospectively reviewed. Regions of interest for HU were measured on three coronal images of the lumbar vertebrae. HU measurement of the whole vertebrae from L1 to L5 was obtained, then HU measurement within concave and convex sides were obtained separately in L5, upper and lower end vertebrae, apex vertebrae, neutral vertebrae, stable vertebrae.

RESULTS

HU value presented a gradually increasing trend from L1 to L5. No correlation was detected between Cobb angle and mean HU value of the 5 lumbar vertebrae, or between Cobb angle and HU value of every lumbar vertebrae separately. HU value was higher within concavity than that within convexity of the same vertebrae both in major and compensatory curve. Asymmetric HU ratio in apex vertebrae positively correlated with Cobb angle. Stable vertebrae were the first proximal vertebrae that present opposite orientation of asymmetric HU ratio from the other lumbar vertebrae.

CONCLUSION

Progression of degenerative scoliosis presents no correlation with osteoporosis based on HU measurement but could increase the asymmetrical vertebral degeneration, especially in apex vertebrae. Distraction of the pedicle screws at concave side, instead of compression of pedicle screws at convex side, should be a priority to correct lumbosacral curve.

LEVEL OF EVIDENCE

3.

Risk prediction of degenerative scoliosis combined with lumbar spinal stenosis in patients with rheumatoid arthritis: a case-control study

The purpose of this study is to compare incidence of degenerative scoliosis (DS) in patients who diagnosed lumbar spinal stenosis (LSS) with or without rheumatoid arthritis (RA) and identify the risk factors of DS severity in RA patients. 61 LSS patients with RA (RA group) and 87 demographic-matched LSS patients without RA (NoRA group) from January 2013 to April 2018 were enrolled. The extracted information includes RA-related parameters such as Steinbrocker classification, disease-modifying anti-rheumatic drugs (DMARDs), and DS-related information such as Cobb angle, apical vertebra, along with osteoporosis and history of total knee arthroplasty (TKA). Comparisons between RA and NoRA group and between DS and non-DS subgroup with RA were performed, as well as the risk factors on DS severity in RA patients. The incidence of DS in RA group was 42.6%, larger than that of NoRA group (P = 0.002). The mean Cobb angle between the two groups was of no difference (P = 0.076). The apical vertebrae were both mainly focused on L3 and L4 vertebrae in both groups with no significant difference on the distribution of apical vertebrae (P = 0.786). Female took a larger proportion in DS subgroup than that of NoDS subgroup in patients with RA (P = 0.039), while Steinbrocker classification was irrelevant to the occurrence of DS and Cobb angle. Multiple regression analysis showed that TKA was a risk factor for the severity of Cobb angle (P = 0.040). The incidence of DS in LSS patients with RA is higher than non-RA patients. RA patients performed TKA sustained less severity of DS.

Impact of shift to the concave side of the C7-center sacral vertical line on de novo degenerative lumbar scoliosis progression in elderly volunteers

BACKGROUND

Degenerative lumbar scoliosis (DLS) is one of the most frequent spinal deformities of the aging spine. The purpose of our study was to clarify the independent predictors of pre-existing DLS progression and their influence on the health related quality of life (HRQOL).

METHODS

This study included 356 volunteers (127 men and 229 women; mean age, 72.2 years; follow-up period, 4 years) who underwent musculoskeletal screening. Standing whole-spine radiographic measurements included the Cobb angle of DLS and C7-center sacral vertical line (C7-CSVL; shift to the concave side of the DLS curve indicated a positive value). A baseline Cobb angle ≥10° indicated pre-existing DLS, and Cobb angle deterioration of ≥4° was considered DLS progression. For HRQOL assessment, the Oswestry Disability Index (ODI) was used. Pre-existing DLS cases were divided into progression and non-progression groups.

RESULTS

Among 93 cases (26.1%) with pre-existing DLS at baseline, 23 cases (pre-existing DLS progression group) showed DLS progression. The mean C7-CSVLs were 10.5 and -3.1 mm in the pre-existing progression and non-progression groups, respectively (p < 0.01). The optimal cutoff C7-CSVL length was 5 mm, with high sensitivity and specificity. Multivariate logistic regression analysis showed that a C7-CSVL ≥5 mm (odds ratio, 3.8; 95% CI: 1.42-10.34; p < 0.01) was independently associated with pre-existing DLS progression. ODI scores deteriorated significantly more in the pre-existing progression group than the non-progression group (+9.8% versus +3.9%; p < 0.05).

CONCLUSIONS

Pre-existing DLS progression is associated with a shift to the concave side of C7-CSVL and influences HRQOL deterioration. It is important to assess coronal global alignment for prediction of a DLS progression.

Characteristics of lumbar scoliosis in patients with rheumatoid arthritis

Background

Although a substantial percentage of patients with rheumatoid arthritis (RA) experience low back pain, the characteristics of lumbar spine pathology in RA patients has been poorly investigated. In our institutions, lumbar spine radiographs indicated scoliosis in 26 patients. The present study aimed to clarify the characteristics of lumbar scoliosis in RA patients.

Methods

This is a retrospective study of 26 RA patients with lumbar scoliosis. Patient characteristics such as disease duration, disease stage and class according to Steinbrocker's classification, and medication for RA and osteoporosis were reviewed. Radiologic evaluation of scoliosis was performed at two different time points by measuring Cobb angles. The progression of scoliosis per year was calculated by dividing the change in Cobb angles by the number of years. Apical vertebral rotation, lateral listhesis, and the level of the intercrestal line at the first observation were also measured. The correlation between different factors and changes in the Cobb angles per year was analyzed.

Results

Majority of the patients had a long disease duration and were classified as stage 3 or 4 according to Steinbrocker's classification. During the observation period, most patients were treated with glucocorticoids. Unlike the previous studies on degenerative scoliosis, apical vertebral rotation, lateral listhesis, and the level of the intercrestal line at initial observation were not significantly related to the progression of scoliosis. Initial Cobb angles were inversely related to the progression of scoliosis. Patients who were treated with bisphosphonates showed slower progression of scoliosis.

Conclusions

Our results indicate that the characteristics of lumbar scoliosis in RA patients differ from those of degenerative lumbar scoliosis. Bone fragility due to the long disease duration, poor control of disease activity, and osteoporosis is possibly related to its progression.

Clinical and radiological outcomes of microscopic partial pediculectomy for degenerative lumbar foraminal stenosis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To investigate the clinical outcomes of microscopic partial pediculectomy for degenerative lumbar craniocaudal foraminal stenosis, risk factors for postsurgical scoliosis progression, and feasibility of postsurgical pedicle screw insertion.

SUMMARY OF BACKGROUND DATA

Previous studies have evaluated surgical strategies for degenerative lumbar foraminal stenosis. Although less invasive decompression surgery is an option for surgical treatment, postsurgical instability and salvaging fusion surgery remain as problems. No analysis has focused on the radiological progression and feasibility of pedicle screw setting after pediculectomy.

METHODS

Microscopic partial pediculectomy by our original method was performed as a first-choice surgical treatment for lumbar radiculopathy due to degenerative craniocaudal foraminal stenosis. This study included 50 consecutive patients followed up for a minimum of 2 years. Clinical outcomes were evaluated with Japanese Orthopaedic Association (JOA) scores and a numerical rating scale. Radiological changes were obtained from standing radiographs. Foraminal height and the minimum pedicle diameter were measured by reconstructed images on multidetector row computed tomography.

RESULTS

The preoperative Japanese Orthopaedic Association score of 14.2 ± 4.2 significantly improved to 21.5 ± 6.2, and 60% of patients were satisfied. The numerical rating scale for lumbar back pain, leg pain, and leg numbness significantly improved. Nine patients (18%) showed lumbar Cobb angle progression of 5° or more within 2 years, and the risk factor for scoliosis progression was surgery at L3-L4 or L4-L5 by multivariate logistic regression analysis. Foraminal height was enlarged from 5.4 mm preoperatively to 8.9 mm postoperatively. The postoperative minimum pedicle diameter was 8.7 ± 1.6 (5.9-11.7) mm.

CONCLUSION

Microscopic lumbar partial pediculectomy provided satisfactory clinical outcomes, but early postsurgical scoliosis progression was likely to occur in patients who underwent the surgery at L3-L4 or L4-L5. Even if a second surgical procedure is needed, pedicle screws can be set on the resected pedicle.

LEVEL OF EVIDENCE

4.

Decreased sleep duration: a risk of progression of degenerative lumbar scoliosis

Degenerative lumbar scoliosis (DLS) is a spinal deformity that develops after skeletal maturity with a Cobb angle of more than 10° in the coronal plane. As the life expectancy of our population increases, DLS becomes a prevalent health issue affecting the quality of life of the elderly. The degree of the scoliosis curvature affects not only the symptoms but also the choice of treatments. Osteoporosis and intervertebral disc degeneration (IDD) have been suggested as two important risks associated with the progression of DLS. Interestingly, recent data implicate interleukin-1 (IL-1) in the altered matrix biology that characterizes human IDD. Compelling evidence links decreased sleep duration to lower bone mineral density (BMD) and elevated expression of IL-1. Based on these evidences, we propose that decreased sleep duration might be a risk of the progression of DLS, and hypothesize that the underlying mechanisms might be the elevated excretion of glucocorticoids and elevated expression of IL-1.