Risk factors for degenerative spondylolisthesis: a systematic review

Patient-reported outcome of lumbar decompression with instrumented fusion for low-grade spondylolisthesis: influence of pathology and baseline symptoms

INTRODUCTION

Low-grade isthmic and degenerative spondylolisthesis (DS) of the lumbar spine are distinct pathologies but both can be treated with lumbar decompression with fusion. In a very large cohort, we compared patient-reported outcome in relation to the pathology and chief complaint at baseline.

METHODS

This was a retrospective analysis using the EUROSPINE Spine Tango Registry. We included 582 patients (age 60 ± 15 years; 65% female), divided into four groups based on two variables: type of spondylolisthesis and chief pain complaint (leg pain (LP) versus back pain). Patients completed the COMI preoperatively and up to 5 years follow-up (FU), and rated global treatment outcome (GTO). Regression models were used to predict COMI-scores at FU. Pain scores and satisfaction ratings were analysed.

RESULTS

All patients experienced pronounced reductions in COMI scores. Relative to the other groups, the DS-LP group showed between 5% and 11% greater COMI score reduction (p < 0.01 up to 2 years' FU). This group also performed best with respect to pain outcomes and satisfaction. Long-term GTO was 93% at the 5 year FU, compared with between 82% and 86% in the other groups.

CONCLUSION

Regardless of the type of spondylolisthesis, all groups experienced an improvement in COMI score after surgery. Patients with DS and LP as their chief complaint appear to benefit more than other patients. These results are the first to show that the type of the spondylolisthesis and its chief complaint have an impact on surgical outcome. They will be informative for the consent process prior to surgery and can be used to build predictive models for individual outcome.

Evolution of lumbar degenerative spondylolisthesis with key radiographic features

Spondylolisthesis is a common finding in middle-aged and older adults with back pain. The pathophysiology of degenerative spondylolisthesis is a subject of controversy regarding not only its etiology but also the mechanisms of its progression. It is theorized that degeneration of the facets and discs can lead to segmental instability, leading to displacement over time. Kirkaldy-Willis divided degenerative spondylolisthesis into three phases: dysfunction, instability, and finally, restabilization. There is a paucity of literature on the unification of the radiological hallmarks seen in spondylolisthesis within these phases. The radiographic features include (1) facet morphology/arthropathy, (2) facet effusion, (3) facet vacuum, (4) synovial cyst, (5) interspinous ligament bursitis, and (6) vacuum disc as markers of dysfunction, instability, and/or restabilization. We discuss these features, which can be seen on X-ray, CT, and MRI, with the intention of establishing a timeline upon which they present clinically. Spondylolisthesis is initiated as either degeneration of the intervertebral disc or facet joints. Early degeneration can be seen as facet vacuum without considerable arthropathy. As the vertebral segment becomes increasingly dynamic, fluid accumulates within the facet joint space. Further degeneration will lead to the advancement of facet arthropathy, degenerative disc disease, and posterior ligamentous complex pathology. Facet effusion can eventually be replaced with a vacuum in severe facet osteoarthritis. Intervertebral disc vacuum continues to accumulate with further cleft formation and degeneration. Ultimately, autofusion of the vertebra at the facets and endplates can be observed. With this review, we hope to increase awareness of these radiographical markers and their timeline, thus placing them within the framework of the currently accepted model of degenerative spondylolisthesis, to help guide future research and to help refine management guidelines.

Improvement in Pain, Quality of Life, and Urinary Dysfunction following Correction of Lumbar Lordosis and Reduction in Lumbar Spondylolistheses Using Chiropractic BioPhysics® Structural Spinal Rehabilitation: A Case Series with >1-Year Long-Term Follow-Up Exams

(1) Background: Lumbar spondylolisthesis affects ~20% of the US population and causes spine-related pain and disability. (2) Methods: This series reports on three patients (two females and one male) aged 68-71 years showing improvements in back pain, quality of life (QOL), and urinary dysfunction following correction of lumbar spondylolistheses using CBP® spinal rehabilitation. Pre-treatment radiographs showed lumbar hyperlordosis (-49.6°, ideal is -40°) and anterolisthesis (14.5 mm, ideal is 0 mm). Pre-treatment patient-reported outcome measures (PROMs) included a numeric rating scale (NRS) for back pain (7.3/10, ideal is 0), urinary urgency (8/10, ideal is 0), and SF-36 physical (PCS) and mental component score (MCS) (29.8 and 46.6, ideal is 46.8 and 52.8). Patients underwent 2-3 CBP® sessions per week to correct lumbar hyperlordosis and lumbar anterolistheses. (3) Results: Post-treatment radiographs showed improvements in lumbar curvature (-42.8°) and anterolisthesis (4.2 mm). Post-treatment PROMs showed improvements in NRS for back pain (1/10), urinary urgency (2.3/10), and SF-36 PCS and MCS (50.2 and 57.7). Long-term follow-up radiographs and PROMs showed maintained improvements. (4) Conclusions: This series documents the first-recorded long-term corrections of lumbar spondylolisthesis and concomitant improvements in back pain, urinary urgency, and QOL using CBP®. This series provides evidence for CBP® as a non-surgical approach to lumbar spinal rehabilitation and the possible impacts of spinal alignment on pain, urinary dysfunction, and QOL.

A possible correlation between facet orientation and development of degenerative cervical spinal stenosis

BACKGROUND

Previous studies have demonstrated the relationship between sagittal facet orientation and cervical degenerative spondylolisthesis. However, the associations between facet orientation and cervical spinal stenosis (CSS) have rarely been studied.

METHODS

One hundred twenty patients with CSS (CSS group) and 120 healthy participants (control group) were consecutively enrolled. The cervical facet angles and anteroposterior diameter (A-P diameter) of spinal canal at each subaxial cervical levels were measured using axial magnetic resonance imaging. The intersection angle of the midsagittal line of the vertebra to the facet line represents the orientation of the facet joint.

RESULTS

The facet angles on the right side at C2- C3 and C3-C4 in CSS group and at C2- C3 in control group had significantly higher values than those of the other sides. Besides, the facet angles and A-P diameter of spinal canal in CSS group were significantly smaller than those in control group at all levels (p < 0.05).

CONCLUSIONS

Our study demonstrated that patients with CSS have smaller axial cervical facet joint angles compared to the healthy individuals. Further studies are needed to elicit the specific underlying mechanism between sagittalization of the cervical facet joints and the pathology of CSS.

Cervical Radiculopathy Presenting as Ischemic Stroke After Carotid Artery Stent Placement

Abrupt loss of focal brain function is the main characteristic of the beginning of ischemic stroke. However, individuals with disorders other than stroke can also present with similar features. These conditions include seizure disorders, migraine, central nervous system abscess or tumor, head trauma, subdural hematoma, cerebral venous thrombosis, viral encephalitis, conversion reaction, hypertensive encephalopathy, multiple sclerosis, and spinal cord disorder. An 82-year-old man presented with a sudden onset of numbness in his left forearm in the distribution of C6 and C7 spinal nerves, 2 days after undergoing endarterectomy and stent placement in his right carotid artery because of stenosis. He was diagnosed with hypo-pharyngeal squamous cell carcinoma (T1, L0, M0) 17 years earlier (2006) which was treated with 70 Gy intensity-modulated radiotherapy (IMRT). The patient underwent stent insertion into his left carotid artery 3.5 years earlier because of 80% carotid artery stenosis. He was initially suspected to have an ischemic stroke. However, computed tomography angiography of the head and neck did not show stenosis or occlusion of the major intracranial arteries and no aneurysms were identified. It showed interval stenting of the cervical portion of the right carotid artery and stable appearance of left carotid artery stent. Both carotid artery stents and the vertebral arteries were patent. The cervical spine showed bilateral moderate to severe foramen stenosis in C3-C4 and C5-C6, and moderate to severe stenosis in the right C2-C3 and left C4-C5. His symptoms subsided after performing neck extension exercises. This is the first report of a patient whose cervical radiculopathy symptoms were suspected to be caused by ischemic stroke. The recent angioplasty and stent placement in the right carotid artery made the association more likely and had to be excluded. Clinicians should be aware that cervical radiculopathy could present as ischemic stroke. It is therefore important that disorders that cause symptoms similar to ischemic stroke are also considered in these individuals.

Factors Predisposing to The Formation of Degenerative Spondylolisthesis-A Narrative Review

The relationship between various factors predisposing to the formation of spondylolisthesis, including degenerative spondylolisthesis, has been analyzed by many authors. However, not all observations are consistent. In this review, we identified factors whose impact on the prevalence of spondylolisthesis was most often mentioned in the literature. These included gender, age, bone mineral density, ethnic origin, and oophorectomy. The results were inclusive in terms of physical activity, pregnancy status, and use of hormone replacement therapy. Associations between diabetes and smoking were very poorly marked. The literature so far has identified a number of factors significantly affecting the incidence of degenerative spondylolisthesis. These include age, gender, body weight, ethnic origin, bone mineral density, and hormonal balance. Radiological parameters, which include iliac crest, pelvic tilt, pelvic incidence, sacral slope, and lumbar lordosis, may also be of great importance for assessing changes in the occurrence and progression. However, the authors do not agree on the real significance of individual factors. The aim of this review was to identify the factors predisposing to the formation of degenerative spondylolisthesis, the importance of which has been suggested in the current literature. The systematization of knowledge in this field can allow a more accurate adjustment of the treatment plan for each patient affected by this condition.

Identification of Novel Genetic Markers for the Risk of Spinal Pathologies: A Genome-Wide Association Study of 2 Biobanks

BACKGROUND

Identifying genetic risk factors for spinal disorders may lead to knowledge regarding underlying molecular mechanisms and the development of new treatments.

METHODS

Cases of lumbar spondylolisthesis, spinal stenosis, degenerative disc disease, and pseudarthrosis after spinal fusion were identified from the UK Biobank. Controls were patients without the diagnosis. Whole-genome regressions were used to test for genetic variants potentially implicated in the occurrence of each phenotype. External validation was performed in FinnGen.

RESULTS

A total of 389,413 participants were identified from the UK Biobank. A locus on chromosome 2 spanning GFPT1, NFU1, AAK1, and LOC124906020 was implicated in lumbar spondylolisthesis. Two loci on chromosomes 2 and 12 spanning genes GFPT1, NFU1, and PDE3A were implicated in spinal stenosis. Three loci on chromosomes 6, 10, and 15 spanning genes CHST3, LOC102723493, and SMAD3 were implicated in degenerative disc disease. Finally, 2 novel loci on chromosomes 5 and 9, with the latter corresponding to the LOC105376270 gene, were implicated in pseudarthrosis. Some of these variants associated with spinal stenosis and degenerative disc disease were also replicated in FinnGen.

CONCLUSIONS

This study revealed nucleotide variations in select genetic loci that were potentially implicated in 4 different spinal pathologies, providing potential insights into the pathological mechanisms.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Factors associated with an increased risk of developing postoperative symptomatic lumbar spondylolisthesis after decompression surgery: an explorative two-centre international cohort study

PURPOSE

Symptomatic lumbar spinal stenosis can be treated with decompression surgery. A recent review reported that, after decompression surgery, 1.6-32.0% of patients develop postoperative symptomatic spondylolisthesis and may therefore be indicated for lumbar fusion surgery. The latter can be more challenging due to the altered anatomy and scar tissue. It remains unclear why some patients get recurrent neurological complaints due to postoperative symptomatic spondylolisthesis, though some associations have been suggested. This study explores the association between key demographic, biological and radiological factors and postoperative symptomatic spondylolisthesis after lumbar decompression.

METHODS

This retrospective cohort study included patients who had undergone lumbar spinal decompression surgery between January 2014 and December 2016 at one of two Spine Centres in the Netherlands or Switzerland and had a follow-up of two years. Patient characteristics, details of the surgical procedure and recurrent neurological complaints were retrieved from patient files. Preoperative MRI scans and conventional radiograms (CRs) of the lumbar spine were evaluated for multiple morphological characteristics. Postoperative spondylolisthesis was evaluated on postoperative MRI scans. For variables assessed on a whole patient basis, patients with and without postoperative symptomatic spondylolisthesis were compared. For variables assessed on the basis of the operated segment(s), surgical levels that did or did not develop postoperative spondylolisthesis were compared. Univariable and multivariable logistic regression analyses were used to identify associations with postoperative symptomatic spondylolisthesis.

RESULTS

Seven hundred and sixteen patients with 1094 surgical levels were included in the analyses. (In total, 300 patients had undergone multilevel surgery.) ICCs for intraobserver and interobserver reliability of CR and MRI variables ranged between 0.81 and 0.99 and 0.67 and 0.97, respectively. In total, 66 of 716 included patients suffered from postoperative symptomatic spondylolisthesis (9.2%). Multivariable regression analyses of patient-basis variables showed that being female [odds ratio (OR) 1.2, 95%CI 1.07-3.09] was associated with postoperative symptomatic spondylolisthesis. Higher BMI (OR 0.93, 95%CI 0.88-0.99) was associated with a lower probability of having postoperative symptomatic spondylolisthesis. Multivariable regression analyses of surgical level-basis variables showed that levels with preoperative spondylolisthesis (OR 17.30, 95%CI 10.27-29.07) and the level of surgery, most importantly level L4L5 compared with levels L1L3 (OR 2.80, 95%CI 0.78-10.08), were associated with postoperative symptomatic spondylolisthesis; greater facet joint angles (i.e. less sagittal-oriented facets) were associated with a lower probability of postoperative symptomatic spondylolisthesis (OR 0.97, 95%CI 0.95-0.99).

CONCLUSION

Being female was associated with a higher probability of having postoperative symptomatic spondylolisthesis, while having a higher BMI was associated with a lower probability. When looking at factors related to postoperative symptomatic spondylolisthesis at the surgical level, preoperative spondylolisthesis, more sagittal orientated facet angles and surgical level (most significantly level L4L5 compared to levels L1L3) showed significant associations. These associations could be used as a basis for devising patient selection criteria, stratifying patients or performing subgroup analyses in future studies regarding decompression surgery with or without fusion.

Current Clinical Concepts: Management of Common Lumbar Spine Posterior Column Disorders in Young, Active Individuals

Although posterior column disorders, such as spondylolysis and spondylolisthesis, are not commonly encountered in the general population, athletic trainers frequently see these conditions in athletic and active individuals due to the repetitive spinal extension and rotational loads placed on the pars interarticularis while participating in sport. Athletic trainers can successfully evaluate patients with posterior column disorders by performing a complete and comprehensive clinical examination to identify the location of pain, test spinal stability, and recognize compensatory movement patterns. Conservative management typically leads to a successful outcome in this population, with rest, bracing, and the use of therapeutic exercise having the best supporting evidence. In this Current Clinical Concepts review, we outlined the etiology and risk factors frequently associated with disorders of the posterior column. Additionally, we synthesized the literature for common evaluation techniques and interventions associated with the posterior column and provided a proposed rehabilitation progression to use in a younger, athletic population.

Postural stability, body composition and functional ability of the lower extremity in patients with lumbar degenerative spondylolisthesis

Although patients accessing rehabilitation services had been reported to have better functional ability of the lower limbs, postural stability, and low cardiovascular disease risk factors, updated data from developing countries is however vital for clinical practices. Hence, the aim of this study was to present the association between lower extremity functional ability (LEFA), stability, and body composition profiles in rehabilitative lumbar degenerative spondylolisthesis (LDS) patients considering age and gender. One hundred and twenty-four participants (45 females, 79 males), with a mean age of 56.45±11.13 years, volunteered for the study. Weight, height body fat percent (BFP), visceral fat, body mass index (BMI), resting systolic and diastolic blood pressure, and resting heart rate were measured while functional ability and stability tests were conducted on the participants. 53.4% were at least overweight; LEFA was below average, stability of both dominant and nondominant legs was very poor, blood pressure and heart rate were high. Women had high total body fat and visceral fat. Significant differences were observed in BMI (p=0.044) and BFP (p=0.035) based on age classification as well as BMI (p=0.000), BFP (p=0.000) and visceral fat (p=0.000) by gender. Overweight, high blood pressure, poor LEFA, and postural stability are crucial comorbidities of Ghanaian LDS patients in this study. Educationally and pragmatically comprehensive healthy lifestyle interventions of regular exercise regimes, adequate and quality nutrition, and occupational stress reduction would play major complementary roles in chiropractic treatment.

Improved Pain and Quality of Life with Corrected Thoracic and Lumbosacral Spondylolisthesis Subluxations Using CBP®: A Case Study and 1-Year Follow-Up

Objective

Discuss non-surgical spinal rehabilitation for a 27-year-old male with thoracic and lumbosacral spondylolistheses. A selective literature review and discussion are provided.

Clinical Features

A 27-year-old male presented with severe, 8/10 mid and low back pain. Initial lateral thoracic and lumbar x-rays revealed grade 1 spondylolistheses at T9-T10 and L5-S1 measuring -5.3 mm and -6.8 mm.

Interventions and Outcomes

The patient completed 60 sessions of Mirror Image® spinal adjustments, exercises, and traction over 30 weeks. Post-treatment x-rays showed correction in translations at T9-T10 and L5-S1 from -5.3 mm to 0.0 mm and -6.8 mm to -1.0 mm, within normal limits. 1-year follow-up x-rays showed maintained correction.

Conclusions

This case is the first documented evidence of non-surgical or chiropractic treatment for thoracic and lumbosacral spondylolistheses where spinal alignment was corrected. More research is needed to investigate the clinical implications and applications.

Lumbar Spondylolisthesis Progression: What is the Effect of Lumbar Medial Branch Nerve Radiofrequency Ablation on Lumbar Spondylolisthesis Progression? A Single-Center, Observational Study

BACKGROUND

Radiofrequency ablation (RFA) is a denervation therapy commonly performed for pain of facet etiology. Degenerative spondylolisthesis, a malalignment of the spinal vertebrae, may be a co-existing condition contributing to pain; yet the effect of RFA on advancing listhesis is unknown. To the extent that denervating RFA may weaken paraspinal muscles that provide stability to the spine, the therapy can potentially contribute to progressive spinal instability.

METHODS

Single-center, prospective, observational pilot study in an interventional pain practice to test the hypothesis that RFA of painful facets in the setting of spondylolisthesis may contribute to advancement of further degenerative spondylolisthesis. Fifteen participants with pre-existing degenerative Grade I or Grade II spondylolisthesis and coexisting axial lumbar pain underwent lumbar RFA encompassing spondylolisthesis level and followed with post-RFA imaging at 12 months and beyond to measure percent change in spondylolisthesis.

RESULTS

The primary outcome was the percent advancement of spondylolisthesis per year measured on post-RFA lateral lumbar spine imaging compared with non-intervention inferred baseline advancement of 2% per very limited observational studies. Among the 15 participants enrolled, 14 completed the study (median age 66; 64.3% women; median BMI 33.5; mean follow-up time 23.9 months). The mean advancement of spondylolisthesis per year after RFA was 1.30% (95% CI -0.14 to 2.78%), with 9/14 below 1.25%.

CONCLUSION

Among patients with lumbar pain originating from facets in the setting of degenerative spondylolisthesis who underwent lumbar RFA, the observed advancement of spondylolisthesis is clinically similar to the estimated maximum baseline of 2% per year change. The study findings did not find a destabilizing effect of lumbar RFA in advancing spondylolisthesis in this patient population.

Pathomechanisms and Predisposing Factors for Degenerative Lumbar Spondylolisthesis: A Narrative Review

The pathomechanism of degenerative lumbar spondylolisthesis (DLS) is not fully understood and is likely to be multifactorial. The primary cause of DLS likely is age-related degeneration of all of the components of the segments and their surroundings. Subsequently, additional factors, such as anatomical, hormonal, and mechanical stress factors, may drive the spinal segments to DLS. Reported predisposing factors that have shown a consistent association with DLS include older age, female sex, sagittal facet joint orientation, and high pelvic incidence. Future prospective epidemiological studies that include large groups of subjects and use multivariate analyses of the possible predisposing factors are needed.

Clinical and radiological features of lumbar degenerative spondylolisthesis who complicates osteoarthritis of the knee

BACKGROUND DATA

Correlation between lumbar degenerative disease and degenerative disorders of the knee joint have often been reported, however, detailed research concerning lumbar degenerative spondylolisthesis (DS) who complicates osteoarthritis of the knee (KOA) are scarce.

METHODS

A total of 184 consecutive surgically treated DS patients were identified, and divided into two groups: DS patients who complicate KOA (KOA group) and DS patients without KOA (non-KOA group). DS was defined as grade 1 or more, according to Meyerding's classification, and KOA was defined as grade 3 or more according to Kellgren-Lawrence classification. Clinical and the radiological differences of DS patients between KOA group and non-KOA group were investigated in order to clarify the features of DS patients who complicate KOA. Statistical significance using student's t-test and multivariate logistic regression analysis was performed to identify independent predictors of complicating KOA in DS.

RESULTS

KOA group and non-KOA group consisted of 57 and 127 patients, respectively, with both group predominantly of female patients. Clinical features of KOA group were significantly high in age and body mass index (BMI), and more likely to complicate circulatory system disorders than non-KOA group. Radiological features of KOA group were significantly high in frequency of double adjacent level spondylolisthesis, Pelvic incidence (PI), Pelvic tilt (PT), and PI-LL. Multivariate logistic regression analysis identified coexistence of circulatory system disorders (OR 2.251, p = 0.024) and PI-LL (OR 1.04, p < 0.001) to be an independent predictors of complicating KOA in DS patients.

CONCLUSIONS

Older age and overweighted female patients coexistence of circulatory system disorders, containing double adjacent level spondylolisthesis with high PI, PT, and PI-LL were the characteristics of DS patients who complicate KOA, particularly coexistence of circulatory system disorders and significantly high lumbo-pelvic sagittal mismatch were the most significant factors above all.

Influence of comorbid knee osteoarthritis on surgical outcome and sagittal spinopelvic/lower-extremity alignment in elderly patients with degenerative lumbar spondylolisthesis undergoing transforaminal lumbar interbody fusion

OBJECTIVE

This retrospective study aimed to clarify the influence of comorbid severe knee osteoarthritis (KOA) on surgical outcome in terms of sagittal spinopelvic/lower-extremity alignment in elderly patients with degenerative lumbar spondylolisthesis (DLS).

METHODS

In total, 110 patients aged at least 65 years (27 men, 83 women; mean age 74.0 years) who underwent short-segment lumbar fusion were included in the present study. Using the Kellgren-Lawrence (KL) grading system, patients were categorized into those with no to mild KOA (the mild-OA group: KL grades 0-2), moderate KOA (moderate-OA group: KL grade 3), or severe KOA (severe-OA group: KL grade 4). Surgical results were assessed using the Japanese Orthopaedic Association (JOA) scoring system, and spinopelvic/lower-extremity parameters were compared among the 3 groups. Adjacent-segment disease (ASD) was assessed over a mean follow-up period of 4.7 years (range 2-8.1 years).

RESULTS

The study cohort was split into the mild-OA group (42 patients), the moderate-OA group (28 patients), and the severe-OA group (40 patients). The severe-OA group contained significantly more women (p = 0.037) and patients with double-level listhesis (p = 0.012) compared with the other groups. No significant differences were found in mean postoperative JOA scores or recovery rate among the 3 groups. The mean postoperative JOA subscore for restriction of activities of daily living was only significantly lower in the severe-OA group compared with the other groups (p = 0.010). The severe-OA group exhibited significantly greater pelvic incidence, pelvic tilt, and knee flexion angle (KFA), along with a smaller degree of lumbar lordosis than the mild-OA group both pre- and postoperatively (all p < 0.05). Overall, the rate of radiographic ASD was observed to be higher in the severe-OA group than in the mild-OA group (p = 0.015). Patients with ASD in the severe-OA group exhibited significantly greater pelvic tilt, pre- and postoperatively, along with less lumbar lordosis, than the patients without ASD postoperatively (all p < 0.05).

CONCLUSIONS

A lack of lumbar lordosis caused by double-level listhesis and knee flexion contracture compensated for by far greater pelvic retroversion is experienced by elderly patients with DLS and severe KOA. Therefore, corrective lumbar surgery and knee arthroplasty may be considered to improve sagittal alignment, which may contribute to the prevention of ASD, resulting in favorable long-term surgical outcomes.

XLIF interbody cage reduces stress and strain of fixation in spinal reconstructive surgery in comparison with TLIF cage with bilateral or unilateral fixation: a computational analysis

In treating recalcitrant low back pain, extreme lateral lumbar interbody fusion (XLIF) with a large cage is reported to have better stability compared to approach of transforaminal lumbar interbody fusion (TLIF) using a small cage. In addition, bilateral pedicle screw fixation (PSF) in comparison with unilateral fixation achieved no inferior fusion rate, but with a significant reduction in operation time and blood loss. The aim of the study was to understand the mechanism underpinning the stability of lumbar interbody fusion using different cage sizes with unilateral or bilateral PSF. A computer model of human lumbar vertebrae L4 and L5 with implants was reconstructed based on CT scans and simulated in Ansys Workbench. Simulation results demonstrated that for either XLIF or TLIF cages, the maximum values of rod stress were comparable with bilateral and unilateral PSF. However, the stability was considerably reduced with unilateral PSF for TLIF due to significantly increased facet joint strain for TLIF; whereas for XLIF with left unilateral PSF, the max facet joint strain was comparable to bilateral PSF, possibly due to facet tropism of this specific subject.

Is radiographic lumbar spondylolisthesis associated with occupational exposures? Findings from a nested case control study within the Wakayama spine study

Background

To explore the relationship between radiographic spondylolisthesis and occupational factors in a case-control study nested within the Wakayama Spine Study (WSS).

Methods

The WSS is a cross-sectional observational study amongst Japanese adults. All participants completed a lifetime occupational history and underwent X-rays of the lumbar spine (L1-S1) according to a pre-defined protocol. One trained surgeon graded the presence of a spondylolisthesis based upon ≥5% anterior or posterior slip at one or more levels. Cases, with lumbar spondylolisthesis, were compared with controls without, for their principal occupation and occupational exposures.

Results

In total, data were available for 722 adults (245 men and 477 women), mean age 70.1 (range 53–93) years. According to the pre-defined radiographic criteria, 117 were defined with spondylolisthesis (cases), leaving 605 controls. Cases were not significantly different from controls for age, gender, BMI, smoking or alcohol intake. However, cases were more than twice as likely to report occupational driving ≥4 h/day (OR 2.39, 95% CI 1.08–5.27) after adjustment for age, gender and BMI. Additionally, after stratification by age using 75 years as a cut-point, cases were more than 3-fold more likely to report having worked in the agricultural/ fishing industries (OR 3.47, 95% CI 1.29–9.29) among those aged < 75 years. A reduced risk of being a case was associated with climbing slopes/steps and walking.

Conclusions

A history of occupational driving and working in the agricultural/fishing industry were associated with radiographic spondylolisthesis in this cross-sectional population study. This finding requires further evaluation in longitudinal studies.

A comparative study of gait characteristics associated with and without degenerative lumbar spondylolisthesis in patients with lumbar spinal stenosis

BACKGROUND

Reported characteristics of DS include forward slippage of the superior lumbar relative to the inferior lumbar, lumbar instability, increased lumbar lordotic angle, and high body mass index (BMI). However, to our knowledge, only static measurements were conducted in previous studies, and no dynamic observations exist. In this crosssectional study, the gait of patients with and without DS in LSS was compared, and their characteristics were examined using a three-dimensional motion analysis system.

METHODS

In total, 42 patients with LSS were included. Lumbar lordosis angle, sacral tilt angle, lumbar slip rate determined from X-ray images, the Zurich Claudication Questionnaire (ZCQ), the visual analog scale (VAS), and BMI were evaluated. U-COM length was the distance between the upper center of mass (COM) and the body's COM, while L-COM length was the distance between the lower COM and the COM. Each DS and Non-DS group evaluation was compared using the Mann-Whitney U-test. Additionally, multivariate analysis was performed using factors with significant differences as explanatory variables and with or without DS as the target variable.

RESULTS

Lumbar lordotic angle was significantly higher in the DS group and there was a significant difference between U-COM and L-COM lengths in the sagittal planes at heel contact (HC) and toe-off (TO). L-COM length at HC and TO was a significant variable when the lumbar lordotic angle was adjusted as a confounding factor in multivariate analysis.

CONCLUSIONS

The U-COM and L-COM lengths in the DS group were both extended and the line connecting each COM was inclined backward on the sagittal plane at HC and TO during gait. Our study showed that L-COM length was associated with or without DS.

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.

A Radiological Study of the Association of Facet Joint Tropism and Facet Angulation With Degenerative Spondylolisthesis

Objective

To study the association of facet joint angulation and joint tropism with degenerative spondylolisthesis (DS) through a comparison with a matched control group.

Methods

This radiographic study was carried out in 2 groups of 45 patients each. Group A contained patients with single-level DS, while group B (control) contained non-DS patients with similar age and degeneration who underwent surgery for disc prolapse or lumbar stenosis. DS was diagnosed based on translation of ≥ 3 mm on standing lateral radiography. Axial magnetic resonance imaging from L3 to S1 was utilized to assess the angulation of facet joints in relation to the coronal plane; a difference of ≥ 8° was considered to indicate tropism.

Results

Among 45 patients with DS, 15 were males and 30 females. Their mean age was 62.2 years. Facet tropism was identified in 20 of 45 patients at the level of DS, 12 patients at a level proximal to DS, and 15 patients at a level distal to DS. Facet tropism was found in 7 of the 45 patients in group B. At L3–4, facet tropism was observed in 13 patients (28.88%) in group A and 2 (4.44%) in group B. At L4–5, tropism was observed in 19 patients (42.22%) in group A and 5 (11.11%) in group B. At L5–S1, tropism was seen in 17 patients (37.77%) in group A and 2 (4.44%) in group B. Group A showed a significantly higher prevalence of multilevel facet tropism and tropism at levels adjacent to the DS level. A higher average angulation of facet joints was observed in the DS group, but the difference was not statistically significant at all levels.

Conclusion

The present study documented a statistically significant relationship between facet tropism and DS. A higher prevalence of facet tropism was also found in DS patients at non-DS levels, which is a novel observation. This finding supports the argument that facet tropism is a pre-existing morphological variation contributing to the development of DS, not a result of secondary remodelling.

Radiographic Classification for Degenerative Spondylolisthesis of the Lumbar Spine Based on Sagittal Balance: A Reliability Study

STUDY DESIGN

Inter- and intraobserver reliability study.

OBJECT

To assess the reliability of a new radiographic classification of degenerative spondylolisthesis of the lumbar spine (DSLS).

SUMMARY OF BACKGROUND DATA

DSLS is a common cause of chronic low back and leg pain in adults. To this date, there is no consensus for a comprehensive analysis of DSLS. The reliability of a new DSLS classification system based on sagittal alignment was assessed.

METHODS

Ninety-nine patients admitted to our spinal surgery department for surgical treatment of DSLS between January 2012 and December 2015 were included. Three observers measured sagittal alignment parameters with validated software: segmental lordosis (SL), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sagittal vertical axis (SVA). Full body low-dose lateral view radiographs were analyzed and classified according to three main types: Type 1A: preserved LL and SL; Type 1B: preserved LL and reduced SL (≤5°); Type 2A: PI-LL ≥10° without pelvic compensation (PT <25°); Type 2B: PI-LL ≥10° with pelvic compensation (PT ≥25°); Type 3: global sagittal malalignment (SVA ≥40 mm). The three observers classified radiographs twice with a 3-week interval for intraobserver reproducibility. Interobserver reproducibility was calculated using Fleiss κ and intra-class coefficient. Intraobserver reproducibility was calculated using Cohen κ.

RESULTS

Mean age was 68.8 ± 9.8 years. Mean sagittal alignment parameters values were the following: PI: 60.1° ± 12.7°; PI-LL was 12.2° ± 13.9°, PT: 24.7° ± 8.5°; SVA: 44.9 mm ± 44.6 mm; SL: 16.6° ± 8.4°. Intraobserver repeatability showed an almost perfect agreement (ICC > 0.92 and Cohen κ > 0.89 for each observer). Fleiss κ value for interobserver reproducibility was 0.82, with percentage agreement among observers between 88% and 89%.

CONCLUSION

This new classification showed an excellent inter- and intraobserver reliability. This simple method could be an additional sagittal balance tool helping surgeons improve their preoperative DSLS analysis.

Increased risk of symptomatic progression of instability following decompression for lumbar canal stenosis in patients receiving chronic glucocorticoids therapy

BACKGROUND

Lumbar decompression surgery is a commonly used treatment for degenerative lumbar spinal stenosis; however, some patients develop symptomatic spinal instability following decompression surgery. The objective of this study was to reveal risk factors for delayed instability following decompression surgery for lumbar spinal stenosis.

METHODS

One hundred ten patients who underwent single-level lumbar decompression between 2008 and 2014 were retrospectively reviewed. Surgical indication for decompression surgery was symptomatic lumbar canal stenosis without spondylolisthesis or with minimum spondylolisthesis (less than 4 mm translation). Patients with gross segmental motion (>10° in disc angle, >2 mm translation) on flexion-extension lumbar radiographs were excluded. Age, sex, body mass index, smoking history, diabetes mellitus, autoimmune connective tissue diseases including rheumatoid arthritis, and the use of glucocorticoids were investigated. Radiographic measurements included disc angle, disc height, slippage, facet angle, segmental motion (flexion-extension), lumbar alignment, facet effusion, and disc degeneration. Data were analyzed using multivariate forward selection stepwise logistic regression, chi-square tests, and Student t-test.

RESULTS

Six of 110 patients (5.5%) developed symptomatic spinal instability at the operative level and underwent spinal fusion surgery at an average of 2.1 years postoperatively. Autoimmune connective tissue disorders and chronic use of glucocorticoids were associated with the occurrence of symptomatic spinal instability requiring spine fusion surgery, while there was no significant difference in radiographic parameters and demographic factors excluding autoimmune connective tissue diseases between reoperation and non-reoperation groups.

CONCLUSIONS

Patients with autoimmune connective tissue disorders receiving chronic glucocorticoid therapy are more likely to develop symptomatic spinal instability following decompression surgery for lumbar canal stenosis without or with minimal spondylolisthesis.

Correction of Grade 2 Spondylolisthesis Following a Non-Surgical Structural Spinal Rehabilitation Protocol Using Lumbar Traction: A Case Study and Selective Review of Literature

Objective

Discuss the use of non-surgical spinal rehabilitation protocol in the case of a 69-year-old female with a grade 2 spondylolisthesis. A selective literature review and discussion are provided.

Clinical Features

A 69-year-old female presented with moderate low back pain (7/10 pain) and severe leg cramping (7/10 pain). Initial lateral lumbar x-ray revealed a grade 2 spondylolisthesis at L4-L5 measuring 13.3 mm.

Interventions and Outcomes

The patient completed 60 sessions of Mirror Image® spinal exercises, adjustments, and traction over 45 weeks. Post-treatment lateral lumbar x-ray showed a decrease in translation of L4-L5 from 13.3 mm to 2.4 mm, within normal limits.

Conclusions

This case provides the first documented evidence of a non-surgical or chiropractic treatment, specifically Chiropractic BioPhysics®, protocols of lumbar spondylolisthesis where spinal alignment was corrected. Additional research is needed to investigate the clinical implications and treatment methods.

Menopause as a potential cause for higher prevalence of low back pain in women than in age-matched men

Female sex hormones play an important role in the aetiology and pathophysiology of a variety of musculoskeletal degenerative diseases. Postmenopausal women show accelerated disc degeneration due to relative oestrogen deficiency, resulting in narrower intervertebral disc space in women than age-matched men, increased prevalence of spondylolisthesis, and increased prevalence of facet joint osteoarthritis. Postmenopausal women also show higher osteoporosis related spine fracture rate, particularly at the thoracic-lumbar junction site. I propose the concept that low back pain (LBP) is more prevalent in postmenopausal women than age-matched men and is associated with the physiological changes caused by the relatively lower level of sex hormones after menopause in women. Considering hormone replacement treatment (HRT)'s consistent efficacy reported with menopause-associated osteoarthritis, an in-depth understanding of the role of the gonadal hormones in LBP modulation warrants further study. HRT initiated at early postmenopausal phase may be protective for recurring LBP. If this is the case, further cost-benefit analysis should be performed for optimal HRT regimen in cases of women with high risk of recurring severe LBP.

Lumbar degenerative spondylolisthesis epidemiology: A systematic review with a focus on gender-specific and age-specific prevalence

The epidemiology of lumbar degenerative spondylolisthesis (DS) remains controversial. We performed a systematic review with the aim of gaining a better understanding of the prevalence of DS in the general population. The results showed that the prevalence of DS is very gender- and age-specific. Few women and men develop DS before they are 50 years old. After 50 years of age, both women and men begin to develop DS, with women having a faster rate of development than men. For elderly Chinese (≥ 65 years, mean age: 72.5 years), large population-based studies MsOS (Hong Kong, females: n = 2000) and MrOS (Hong Kong, males: n = 2000) showed DS prevalence was 25.0% in women and 19.1% in men. The female:male (F:M) prevalence ratio was 1.3:1. The published data for MsOS (USA) and MrOS (USA) studies seem to show that elderly Caucasian Americans have a higher DS prevalence, being approximately 60-70% higher than elderly Chinese; however, the F:M prevalence ratio was similar to the elderly Chinese population. Patient data showed that female patients more often received surgical treatment than male and preliminary data showed the ratio of female to male patients receiving surgical treatment did not differ between Northeast Asians (Chinese, Japanese, and Korean), Europeans, and American Caucasians, being around 2:1 in the elderly population. The existing data also suggest that menopause may be a contributing factor for the accelerated development of DS in postmenopausal women. The translational potential of this article: A better understanding of epidemiology of lumbar degenerative spondylolisthesis can support patient consultation and treatment planning.

Sagittal spinopelvic parameters in 2-level lumbar degenerative spondylolisthesis: A retrospective study

The purpose of our study is to evaluate sagittal parameters in 2-level lumbar degenerative spondylolisthesis (DS) (TLDS).A total of 15 patients with TLDS, 40 patients with single-level DS (SLDS), and 30 normal volunteers as control were included in our study. All subjects performed on full spine X-ray. Two categorized data were analyzed: patient characteristics-age, sex, body mass index, radiographic parameters-pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), sacral slope (SS), PI-LL, Cobb between the fifth thoracic vertebral and 12th thoracic vertebral (T5-T12), sagittal vertical axis (SVA) Cobb angle of spondylolisthesis level (CSL), ratio of PT to SS (PT/SS), CSL/LL, variation trend of SS over PI, and LL over PI.The PI (73.1° vs 52.9°), SS (50.8° vs 32.2°), LL (53.1° vs 46.9°), SVA (66.1 vs 22.0 mm), PI-LL (20.0° vs 6.0°), and CSL (23.6° vs 20.0°) in TLDS were significantly larger than these in SLDS. The PI (73.1° vs 40.6°), PT (22.3° vs 17.1°), SS (50.8° vs 23.5°), LL (53.1° vs 32.5°), PI-LL (20.0° vs 8.1°), and SVA (66.1 vs 17.0 mm) in TLDS were significantly larger than those in the normal group (NG). The PI (52.9° vs 40.6°), PT (21.0° vs 17.1°), SS (32.2° vs 23.5°), LL (46.9° vs 32.5°), and SVA (22.0 vs 17.0 mm) in SLDS were significantly higher than those in NG. However, PT/SS (44.0%), LL over PI (y = 0.39x + 24.25), SS over PI (y = 10.79 + 0.55x) were lower in TLDS than these in SLDS (63.8%, y = 0.41x + 25, y = 0.65x - 2.09, respectively), and the similar tend between SLDS and NG (74.0%, y = 0.49x + 13.09, y = 0.67x - 3.9, respectively).Our results showed that 2-level lumbar DS, which was caused by multiple-factors, has a severe sagittal imbalance, but single-level has not any. When we plan for surgical selection for 2-level lumbar DS, global sagittal balance must be considered.

Facet tropism and facet joint orientation: risk factors for the development of early biochemical alterations of lumbar intervertebral discs

OBJECTIVE

To assess the glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVD) in healthy volunteers with facet tropism (FT) and sagittal facet joint (FJ) orientation using glycosaminoglycan chemical exchange saturation transfer imaging (gagCEST).

METHOD

Seventy-five lumbar IVDs of twenty-five young, healthy volunteers without any history of lumbar spine pathologies (13 female; 12 male; mean age: 28.0 ± 4.4 years; range: 21-35 years) were examined with a 3T MRI scanner. Orientation of FT and FJ were assessed for L3/4, L4/5 and L5/S1 using standard T2 weighted images. Biochemical gagCEST imaging was used to determine the GAG content of each nucleus pulposus (NP) and annulus fibrosus (AF).

RESULTS

Significantly higher gagCEST values of NP were found in volunteers without FT and normal FJ orientation compared to volunteers with FT and sagittal FJ orientation >45° (P < 0.0001). GagCEST values were significantly higher in volunteers without FT compared to volunteers with moderate or severe FT (moderate FT: P < 0.0001; severe FT: P = 0.0033). Volunteers with normal FJ orientation showed significantly higher gagCEST values compared to those with sagittal FJ orientation >45° (P < 0.001). We found a significant, negative correlation between gagCEST values and higher angels in sagittal FJ orientation (rho = -0.459; P < 0.0001).

CONCLUSION

GagCEST analysis indicated lower GAG values of NP in young volunteers with FT and sagittal orientated FJ, indicating that FT and sagittal orientation of the FJ represent risk factors for the development of early biochemical alterations of lumbar IVDs.

Critical Values of Facet Joint Angulation and Tropism in the Development of Lumbar Degenerative Spondylolisthesis: An International, Large-Scale Multicenter Study by the AOSpine Asia Pacific Research Collaboration Consortium

STUDY DESIGN

An international, multicenter cross-sectional image-based study performed in 33 institutions in the Asia Pacific region.

OBJECTIVE

The study addressed the role of facet joint angulation and tropism in relation to L4-L5 degenerative spondylolisthesis (DS).

METHODS

The study included 349 patients (63% females; mean age: 61.8 years) with single-level DS; 82 had no L4-L5 DS (group A) and 267 had L4-L5 DS (group B). Axial computed tomography and magnetic resonance imaging were utilized to assess facet joint angulations and tropism (i.e., asymmetry between facet joint angulations) between groups.

RESULTS

There was a statistically significant difference between group A (left mean: 46.1 degrees; right mean: 48.2 degrees) and group B (left mean: 55.4 degrees; right mean: 57.5 degrees) in relation to bilateral L4-L5 facet joint angulations (p < 0.001). The mean bilateral angulation difference was 7.4 and 9.6 degrees in groups A and B, respectively (p = 0.025). A critical value of 58 degrees or greater significantly increased the likelihood of DS if unilateral (adjusted OR: 2.5; 95% CI: 1.2 to 5.5; p = 0.021) or bilateral facets (adjusted OR: 5.9; 95% CI: 2.7 to 13.2; p < 0.001) were involved. Facet joint tropism was found to be relevant between 16 and 24 degrees angulation difference (adjusted OR: 5.6; 95% CI: 1.2 to 26.1; p = 0.027).

CONCLUSIONS

In one of the largest studies assessing facet joint orientation in patients with DS, greater sagittal facet joint angulation was associated with L4-L5 DS, with a critical value of 58 degrees or greater increasing the likelihood of the condition for unilateral and bilateral facet joint involvement. Specific facet joint tropism categories were noted to be associated with DS.

Is lumbar facet joint tropism developmental or secondary to degeneration? An international, large-scale multicenter study by the AOSpine Asia Pacific Research Collaboration Consortium

BACKGROUND

Facet joint tropism is asymmetry in orientation of the bilateral facets. Some studies have shown that tropism may increase the risk of disc degeneration and herniations, as well as degenerative spondylolisthesis (DS). It remains controversial whether tropism is a pre-existing developmental phenomena or secondary to progressive remodeling of the joint structure due to degenerative changes. As such, the following study addressed the occurrence of tropism of the lower lumbar spine (i.e. L3-S1) in a degenerative spondylolisthesis patient model.

METHODS

An international, multi-center cross-sectional study that consisted of 349 patients with single level DS recruited from 33 spine institutes in the Asia Pacific region was performed. Axial MRI/CT from L3-S1 were utilized to assess left and right facet joint sagittal angulation in relation to the coronal plane. The angulation difference between the bilateral facets was obtained. Tropism was noted if there was 8° or greater angulation difference between the facet joints. Tropism was noted at levels of DS and compared to immediate adjacent and distal non-DS levels, if applicable, to the index level. Age, sex-type and body mass index (BMI) were also noted and assessed in relation to tropism.

RESULTS

Of the 349 subjects, there were 63.0 % females, the mean age was 61.8 years and the mean BMI was 25.6 kg/m(2). Overall, 9.7, 76.5 and 13.8 % had L3-L4, L4-L5 and L5-S1 DS, respectively. Tropism was present in 47.1, 50.6 and 31.3 % of L3-L4, L4-L5 and L5-S1 of levels with DS, respectively. Tropism involved 33.3 to 50.0 % and 33.3 to 58.8 % of the immediate adjacent and most distal non-DS levels from the DS level, respectively. Patient demographics were not found to be significantly related to tropism at any level (p > 0.05).

CONCLUSIONS

To the authors' knowledge, this is one of the largest studies conducted, in particular in an Asian population, addressing facet joint tropism. Although levels with DS were noted to have tropism, immediate adjacent and distal levels with no DS also exhibited tropism, and were not related to age and other patient demographics. This study suggests that facet joint tropism or perhaps subsets of facet joint orientation may have a pre-disposed orientation that may be developmental in origin or a combination with secondary changes due to degenerative/slip effects. The presence of tropism should be noted in all imaging assessments, which may have implications in treatment decision-making, prognostication of disease progression, and predictive modeling. Having a deeper understanding of such concepts may further elaborate on the precision phenotyping of the facets and their role in more personalized spine care. Additional prospective and controlled studies are needed to further validate the findings.

Pelvic retroversion is the key protective mechanism of L4-5 degenerative spondylolisthesis

PURPOSE

To explore the role of spinopelvic sagittal alignment in the pathological mechanism of degenerative spondlylolisthesis (DS) development.

METHOD

A total of 52 asymptomatic volunteers, 32 single segment L4-5 DS and 29 lumbar spinal stenosis (LSS) without spondylolisthesis patients were enrolled. All subjects had standard lumbar spine X-ray films with standard position along with lumbar spine magnetic resonance image. Comparative analysis of sagittal parameters and disc degeneration grades among asymptomatic volunteers and patients with the two disorders were performed.

RESULTS

Compared to normal population (NP) and LSS, DS showed significantly greater pelvic incidence (PI), sacral slope (SS) and lumbar lordosis (LL), while LSS showed significantly smaller PT and PT/SS. DS showed significantly greater L5 slope than NP and LSS. In both Great-PI group and Small-PI group, all above differences between DS and LSS remained. LSS showed significantly higher degenerative grade of each adjacent disc than DS. Population with adjacent segment degeneration showed higher incidence of pelvic retroversion (PT/SS ≥1), and LSS showed greater proportion of adjacent segment degeneration than DS.

CONCLUSIONS

Lumbar spine morphology of great LL determined by great PI is a risk factor of L4-5 DS. L5 slope is a parameter that can be used to predict the risk of L4-5 DS. Pelvic retroversion is the key protective mechanism from DS. Adjacent segment degeneration is a driving factor of pelvic retroversion for compensation of lumbar sagittal malalignment.