Spino-pelvic sagittal balance of spondylolisthesis: a review and classification

Erector spinae could be the game changer in surgical decision-making in patients with lumbar spondylolisthesis: a cross-sectional analysis of an age-, sex-, subtype-, level-matched patients with similar spinopelvic parameters received surgical or conservative management

PURPOSE

In this study we aimed to identify whether paraspinal muscle morphology could play a role in surgical decision-making in patients with lumbar spondylolisthesis.

METHODS

We conducted a cross-sectional analysis of a prospectively collected database between January 2013 and May 2023. Consecutive women and men, who visited our outpatient clinics with chronic LBP, neurogenic claudication, and had lumbar spine magnetic resonance imaging (MRI) for their complaints were included into the preliminary dataset. We compared the patients who had conservative management (conservative group) or underwent surgery for lumbar spondylolisthesis (surgical group) in terms of intervertebral disc degeneration, end-plate changes, fatty infiltration in the paraspinal muscles and spinopelvic parameters.

RESULTS

Conservative and surgical groups were similar in terms of severe IVDD and Modic changes at any lumbar level. Surgical group had significantly fattier erector spinae compared to the conservative group. Regression analysis and ROC analysis revealed an OR of 1.088 and a cut-off value of 17 points for fatty infiltration in the erector spinae to predict which patient could undergo surgery for lumbar spondylolisthesis.

CONCLUSION

Each 1-point increment in fatty infiltration in the erector spinae at any lumbar level increased the likelihood of surgery by 8%. Lumbar spondylolisthesis patients with fatty infiltration score for erector spinae at or above 17 were more likely to have surgery. We recommend clinicians to focus on improving erector spinae muscles in patients with lumbar spondylolisthesis.

Clinical and radiological outcomes of gradual reduction and circumferential fusion of high-grade spondylolisthesis in adolescents: a prospective cohort study of 29 young patients

AIM

The objective of this study was to evaluate the safety and efficacy of a novel technique of formal reduction and circumferential fusion for pediatric high-grade spondylolisthesis (HGS).

PURPOSE

The safety and efficacy of formal reduction for high-grade spondylolisthesis (HGS) has never been thoroughly examined. This study reports the outcomes of 29 children with HGS who underwent a procedure of gradual reduction and circumferential fusion.

METHODS

29 children (13 males, 16 females) were recruited between 2006 and 2010. Radiographic measurements (including % of slip, lumbosacral angle-LSA, pelvic incidence-PI, pelvic tilt-PT, sacral slope-SS, and proximal femoral angle-PFA) and quality of life assessment (SRS-22 questionnaire) were prospectively obtained at baseline and at the last post-operative follow-up (> 2 years post-op). Radiological measurements were used to classify patients according to the Spine Deformity Study Group (SDSG) classification.

RESULTS

Mean baseline slip % was 69.9 ± 16.5%. There were 13 patients with a balanced pelvic (SDSG Type 4) and 16 with an unbalanced pelvis (SDSG Type 5 and 6). On average, a reduction of 45.5 ± 15.3% (range 20-86%) was achieved safely with no major complication. In particular, of the 29 patients, only 3 had a L5 radiculopathy postoperatively that was self-resolved at follow-up. From a radiological standpoint, we observed a mean improvement of LSA from 80.3 ± 17.9° to 91.7 ± 13.6°. We also observed a statistically significant improvement in global HRQOL, and in the function and body image domains.

CONCLUSION

This prospective study suggests that formal reduction of HGS followed by circumferential fusion is safe when using a standardized surgical technique based on gradual reduction. Performing this intervention could also help improve QOL in some patients.

Fusion Surgery for Lumbar Spondylolisthesis: A Systematic Review with Network Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

This study aimed to systematically evaluate the optimal surgical fusion approach for lumbar spondylolisthesis, to provide the latest and most reliable evidence for future clinical practice.

METHODS

A comprehensive search of the PubMed, Ovid-Embase, Web of Science, Cochrane, and Scopus databases was conducted from inception to September 1, 2023, to identify relevant records. Two independent reviewers performed the literature screening, data extraction, and assessment of study quality.

RESULTS

Fifteen randomized controlled trials involving 892 patients met the inclusion criteria. The network evidence plot showed that posterolateral fusion and posterior lumbar interbody fusion (PLIF) were the most used fusion techniques. The network meta-analysis results revealed that minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) had a significantly greater improvement in the Oswestry Disability Index (ODI) compared to endoscopic-TLIF, while PLIF had a significantly better fusion effect than posterolateral fusion. Furthermore, no statistically significant differences were observed between other fusion surgeries in terms of improving ODI, fusion rate, complications, or the improvement of visual analog scale-low back pain. The surface under the cumulative ranking curve results indicated that MIS-TLIF had the greatest potential for improving ODI, visual analog scale-low back pain, and complications, while PLIF had the greatest potential for increasing fusion rates. However, the existing selection bias, measurement bias, reporting bias, and publication bias may have reduced the reliability of the meta-analysis results.

CONCLUSIONS

Among the various fusion surgeries for lumbar spondylolisthesis, MIS-TLIF appears to provide the greatest benefit to patients. However, more high-quality, large-scale studies are needed to further investigate the treatment efficacy of different fusion surgeries for lumbar spondylolisthesis.

Early Experience with Prone Lateral Interbody Fusion in Deformity Correction: A Single-Institution Experience

Background/Objectives: Lateral spine surgery offers effective minimally invasive deformity correction, but traditional approaches often involve separate anterior, lateral, and posterior procedures. The prone lateral technique streamlines this process by allowing single-position access for lateral and posterior surgery, potentially benefiting from the lordosing effect of prone positioning. While previous studies have compared prone lateral to direct lateral for adult degenerative diseases, this retrospective review focuses on the outcomes of adult deformity patients undergoing prone lateral interbody fusion. Methods: Ten adult patients underwent single-position prone lateral surgery for spine deformity correction, with a mean follow-up of 18 months. Results: Results showed significant improvements: sagittal vertical axis decreased by 2.4 cm, lumbar lordosis increased by 9.1°, pelvic tilt improved by 3.3°, segmental lordosis across the fusion construct increased by 12.2°, and coronal Cobb angle improved by 6.3°. These benefits remained consistent over the follow-up period. Correlational analysis showed a positive association between improvements in PROs and SVA and SL. When compared to hybrid approaches, prone lateral yielded greater improvements in SVA. Conclusions: Prone lateral surgery demonstrated favorable outcomes with reasonable perioperative risks. However, further research comparing this technique with standard minimally invasive lateral approaches, hybrid, and open approaches is warranted for a comprehensive evaluation.

[Spondylolisthesis]

Spondylolisthesis is a frequent disease that is found in 20% of the adult population and is particularly accompanied by lumbar back pain. Degenerative spondylolisthesis develops in adulthood and is most often found in the L4/5 segment, in contrast to nondegenerative spondylolisthesis which is most often situated in the L5/S1 segment. Prior to every treatment the heterogeneous disease pattern has to be classified according to the severity grade of the olisthesis and to the Spinal Deformity Study Group (SDSG) classification. High-grade spondylolisthesis should preferably be surgically treated and low-grade spondylolisthesis should preferably be treated conservatively. In approximately 50% of all recently acquired spondylolistheses healing of the lysis can be achieved by a consequently carried out conservative treatment.

Endoscopic MIS-TLIF with Destandau's system: leveraging endoscopy with conventional instruments

This presentation showcases an endoscopic minimally invasive spine surgery (MISS) technique for lumbar interbody fusion. Significantly expanding the scope of Destandau's system within MISS, it serves as a pivotal link to unilateral biportal endoscopy (UBE) for endofusion. The method involves minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using a 4-mm rigid endoscope through Destandau's system. With the widespread familiarity with Destandau's system and the absence of specialized instrument requirements, this approach is easily adoptable, particularly in resource-limited centers. The favorable clinical and radiological outcomes underscore the effectiveness of this technique, propelling the role of endoscopy in MISS, particularly in endofusion. The video can be found here: https://stream.cadmore.media/r10.3171/2024.1.FOCVID23216.

Spondylolysis and Spondylolisthesis in Athletes

This article is an update on spondylolysis and spondylolisthesis in athletes, from diagnosis to treatment, based on our service experience and a literature review.

Philosophies and Surgical Techniques for High-Grade Spondylolisthesis Treatment with Literature Review

Introduction

High-grade spondylolisthesis is defined as cases with more than 50% displacement and spondylolisthesis with Meyerding grade III and higher. The surgical management of high-grade spondylolisthesis is highly controversial. Many surgical methods have been reported such as posterior in situ fusion, instrumented posterior fusion with or without reduction, combined anterior and posterior procedures, spondylectomy with reduction of L4 to the sacrum (for spondyloptosis), and posterior interbody fusion with trans-sacral fixation. The literature has recently mentioned minimally invasive transforaminal lumbar interbody fusion for high-grade spondylolisthesis. This study aimed to review the recent literature that describes the surgical outcomes associated with various surgical techniques used for high-grade spondylolisthesis.

Materials and Methods

Recent articles were searched on search engines such as PubMed and Google Scholar using keywords such as "high-grade spondylolisthesis," "surgical techniques," and "complications."

Discussion

The surgical management of high-grade spondylolisthesis is an area of significant controversy. The literature is replete with regards to the need for reduction, decompression, levels of fusion, the nature of instrumentation, surgical approaches including open, minimally invasive, and "mini-open" procedures, and various techniques for reducing the slip and fusion strategy. The three basic options of high-grade spondylolisthesis include in-situ fusion, partial reduction and fusion, and complete reduction.

Conclusion

Various techniques have been described for high-grade spondylolisthesis. Spine deformity study group classification gives guidelines about balanced and unbalanced pelvis and advises reduction and fusion in case of unbalanced pelvis for correction of biomechanical and global sagittal alignment. Each of the surgical techniques has its advantages and disadvantages. However, individual authors' experience, skill levels, and anatomic reduction with fusion techniques have yielded encouraging results.

Management of low back pain accompanying sagittal plane pathologies in children: Spondylolysis/spondylolisthesis and Scheuermann's disease

Background

Low back pain in childhood was underappreciated for a long time, but recent studies report higher prevalences, up to 70%. Two of the common causes are spondylolyis/spondylolisthesis and Scheuermann's disease. These disorders are relevant in a way they both cause significant back pain, and may disrupt the sagittal spinal balance.

Purpose

To present the current evidence on the diagnosis, natural history and treatment of these disorders with a special focus on sagittal spinal alignment.

Methods

This study is conducted as a literature review.

Results and Conclusions

Spondylolysis and low-grade spondylolisthesis have a benign course and are typically treated conservatively. When pars repair is indicated, pedicle screw-based techniques achieve more than 90% fusion with acceptable complication rates. High-grade spondylolisthesis, however, is frequently progressive. Surgical treatment involves fusion, which can be done in situ or after reduction. Reduction is useful for "unbalanced" patients to acquire sagittal spinopelvic balance, and it is important to distinguish these patients. Despite lowering the risk for pseudoarthrosis, reduction brings a risk for neurologic complications. With re-operation rates as high as 40%, these patients definitely require careful preoperative planning. Scheuermann's disease generally causes back pain in addition to cosmetic discomfort during adolescence. If the kyphosis is lower than 60°, symptoms typically resolve into adulthood with conservative measures only. However, it must be kept in mind that these patients may experience problems with physical performance and have a lower quality of life even when the problem seems to have "resolved". Severe kyphosis and intractable back pain are the most frequently referred surgical indications, and surgery typically involves fusion. Proper utilization of osteotomies and proper selection of the upper and lower fusion levels are of utmost importance to prevent complications in these patients.

Is sagittal spinopelvic alignment a cause of low back pain in pediatric spine pathologies? A review

Purpose

Altered spinopelvic morphology is observed in many spine pathologies occurring during growth. The aim of the study is to better understand the sagittal compensatory mechanisms and their possible influence on the occurrence of pain in selected pediatric spine pathologies.

Methods

A bibliographic search in the PubMed database included articles published between September 1965 and July 2023. The keywords contained in the search were "spondylolysis," "spondylolisthesis," "scoliosis," "kypho," "sagittal," "pediatric," "child," "adolescent," "grow," "development," and "pain."

Results

The largest diversity in sagittal alignment patterns was reported in idiopathic scoliosis, with global flattening of the spine being the most common. Kyphotic deformations occurring during growth are characterized by structural thoracic or thoracolumbar kyphosis compensated by lumbar hyperlordosis and lower pelvic incidence. Whereas in spondylolisthesis, altered morphology of the spinopelvic junction with high values of pelvic incidence is observed. Pain does not seem to be related to sagittal alignment in idiopathic scoliosis. In Scheuermann disease, it is localized at the apex of the deformity and is associated with the curve pattern, whereas in spondylolisthesis, sagittal alignment correlates with pain scores only in high-grade slips.

Conclusion

Most of the patients with spine disorders that occurred during growth present a clinically balanced posture in the sagittal plane. It suggests that compensatory mechanisms before achieving skeletal maturity are really significant. A comprehension of sagittal alignment in spine deformities and its relationship to pain is essential for the proper assessment and treatment of these disorders.

[Spondylolisthesis]

Spondylolisthesis is a frequent disease that is found in 20% of the adult population and is particularly accompanied by lumbar back pain. Degenerative spondylolisthesis develops in adulthood and is most often found in the L4/5 segment, in contrast to nondegenerative spondylolisthesis which is most often situated in the L5/S1 segment. Prior to every treatment the heterogeneous disease pattern has to be classified according to the severity grade of the olisthesis and to the Spinal Deformity Study Group (SDSG) classification. High-grade spondylolisthesis should preferably be surgically treated and low-grade spondylolisthesis should preferably be treated conservatively. In approximately 50% of all recently acquired spondylolistheses healing of the lysis can be achieved by a consequently carried out conservative treatment.

Adolescent idiopathic scoliosis with concomitant spondylolysis: choice of fusion levels and evaluation of the outcomes obtained leaving the lytic level not instrumented

PURPOSE

7% of adolescent idiopathic scoliosis (AIS) patients also present with a pars defect. To date, there are no available data on the results of fusion ending proximal to a spondylolysis in the setting of AIS. The aim of this study was to analyze the outcomes of posterior spinal fusion (PSF) in this patient cohort, to investigate if maintaining the lytic segment unfused represents a safe option.

METHODS

Retrospective review of all patients who received PSF for AIS, presented with a spondylolysis or spondylolisthesis and had a min. 2-year follow-up. Demographic data, instrumented levels, and preoperative radiographic data were collected. Mechanical complications, coronal or sagittal parameters, amount of slippage, and pain levels were evaluated.

RESULTS

Data from 22 patients were available (age 14.4 ± 2.5 years), 18 Lenke 1-2 and 4 Lenke 3-6. 5 patients (24%) had an isthmic spondylolisthesis, all Meyerding I. The mean preoperative Cobb angle of the instrumented curves was 58 ± 13°. For 18 patients, the lowest instrumented vertebra (LIV) was the last touched vertebra (LTV); for 2, LIV was distal to the LTV; for 2, LIV was one level proximal to the LTV. The number of segments between the LIV and the lytic vertebra ranged from 1 to 6. At the last follow-up, no complications were observed. The residual curve below the instrumentation measured 8.5 ± 6.4°, the lordosis below the instrumented levels was 51.4 ± 13°. The magnitude of the isthmic spondylolisthesis remained constant for all included patients. Three patients reported minimal occasional low back pain.

CONCLUSION

The LTV can be safely used as LIV when performing PSF for the management of AIS in patients with L5 spondylolysis.

Management of High-Grade Dysplastic Spondylolisthesis

The Meyerding classification grades the degree of slippage in the sagittal plane on lateral standing neutral imaging: 0% to 25% Grade I, 25% to 50% Grade II, 50% to 75% Grade III, 75% to 100% Grade IV, and greater than 100% Grade V (Spondyloptosis). Grades I and II are considered low-grade and Grades III-V are considered high-grade. There are several etiologies of spondylolisthesis. A classification system of the most common causes: Type I - Dysplastic, Type II - Isthmic (including subtypes: A - Lytic, B - Elongation, and C - Acute fracture), Type III - Degenerative, Type IV - Traumatic, Type V - Pathologic, and Type VI - Iatrogenic. Dysplastic spondylolisthesis is a type of spondylolisthesis that occurs at L5-S1 when dysplastic lumbosacral anatomy is present, and is associated with high-grade slip and spina bifida occulta.

Analysis of Degenerative and Isthmic Lumbar Spondylolisthesis from the Difference of Pelvic Parameters and the Degree of Degeneration through Imaging Data

BACKGROUND

In previous studies, many imaging analyses have been conducted to explore the changes in the intervertebral disc degeneration (DD), facet joint osteoarthritis (FJOA), L4 inclination angle (L4IA), pelvis-related parameters, lumbar lordosis (LL), and paravertebral muscle (PVM) in the occurrence and development of degenerative spinal diseases via measuring the X-ray, CT, and MRI data of clinical patients. However, few studies have quantitatively investigated the pelvic parameters and the degree of spine degeneration in patients with degenerative lumbar spondylolisthesis (DLS) and isthmic lumbar spondylolisthesis (ILS). This study discusses the changes in the imaging parameters of DLS, ILS, and a control group; explores the correlation between different measurement parameters; and discusses their risk factors.

METHODS

We evaluated 164 patients with single L4-L5 grade 1 level degenerative lumbar spondylolisthesis (DLS group), 161 patients with single L4-L5 grade 1 level isthmic lumbar spondylolisthesis (ILS group), and 164 patients with non-specific back pain (control group). The grades of DD and FJOA as well as the percentage of the fat infiltration area (%FIA) of multifidus muscle (MM) at the L4-L5 level were measured via CT and MRI. Lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), the L4 inclination angle (L4IA), and sacral slope (SS) were measured via X-ray film, and the differences among the DLS group, ILS group, and control group were analyzed. Furthermore, the risk factors related to the incidences of the DLS and ILS groups were discussed.

RESULTS

First, the pelvis-related parameters of DLS and ILS patients were 51.91 ± 12.23 and 53.28 ± 11.12, respectively, while those of the control group were 40.13 ± 8.72 (p1 < 0.001, p2 < 0.001). Lumbar lordosis (LL) in DLS patients (39.34 ± 8.57) was significantly lower than in the control group (44.40 ± 11.79, p < 0.001). On the contrary, lumbar lordosis (LL) in the ILS group (55.16 ± 12.31) was significantly higher than in the control group (44.40 ± 11.79, p < 0.001). Secondly, the three groups of patients were characterized by significant variations in the L4 inclination angle (L4IA), disc degeneration (DD), facet joint osteoarthritis (FJOA), pelvis-related parameters, and paravertebral muscle (PVM) (p < 0.05). Finally, logistic regression suggests that the L4IA, FJOA, and PT may be risk factors for the occurrence of DLS, and the occurrence of ILS is correlated with the L4IA, FJOA, DD, PT, and LL.

CONCLUSIONS

Compared with the control group, there are changes in pelvic parameters, the L4IA, LL, DD, FJOA, and PVM in DLS and ILS patients, and the degree is different. The parameters within the same group are related to each other, and DLS and ILS have different risk factors. The mechanical stability of the spine is affected by the parameter and angle changes, which may be of great significance for explaining the cause of spondylolisthesis, evaluating the health of the lumbar spine, and guiding the lifestyles of patients.

Effects of Sacral Slope Changes on the Intervertebral Disc and Hip Joint: A Finite Element Analysis

OBJECTIVE

Spinopelvic parameters are vital components that must be considered when treating patients with spinal disease. Several finite element (FE) studies have explored spinopelvic parameters such as sacral slope (SS) and the impact on the lumbar spine, although no study has examined the effect on the hip and sacroiliac joint (SIJ) on varying SS angles. Therefore, it is necessary to have a biomechanical understanding of the impact on the spinopelvic complex.

METHODS

An FE lumbar, pelvis, and femur model was created from computed tomography scans of a 55-year-old female patient with no abnormalities. Three models were created: a normal model (SS = 26°), a model with high SS (SS = 30°), and a model with low SS (SS = 20°). These models underwent loading for flexion, extension, lateral bending, and axial rotation. Range of motion (ROM), intradiscal pressures, hip joint, and SIJ contact stresses were analyzed.

RESULTS

The high SS model (SS = 30°) indicated the highest ROM in the L5-S1 (slip angle) level and the highest intradiscal pressures. The highest average hip and SIJ contact stresses were present in this model, although the low SS model (SS = 20°) in extension had the largest stresses for the hip and SIJ.

CONCLUSIONS

The results provide evidence that patients with higher SS may be more prone to increased ROM at the slip angle (L5-S1). In addition, patients with higher SS were shown to have higher contact stresses on the hip joint and SIJ, potentially leading to SIJ dysfunction. Clinically, correcting lumbar lordosis including SS is important; however, a high SS may have a negative impact on the intervertebral disc, SIJ, and hip joint.

Scoliosis risk factors and outcomes in children with dysplastic spondylolisthesis undergoing surgical reduction and fixation

Purpose

To explore scoliosis risk factors and outcomes in children with dysplastic spondylolisthesis undergoing surgical reduction and internal fixation.

Methods

We retrospectively analyzed 56 children with dysplastic spondylolisthesis who underwent surgical reduction and internal fixation. Patients were grouped according to presence of scoliosis before surgery. Radiographic parameters measured before surgery included pelvic incidence, pelvic tilt, sacral slope, coronal Cobb angle, slip percentage, Dubousset's lumbosacral angle, lumbar lordosis, sagittal vertical axis, and Spinal Deformity Study Group index. Groups were compared using logistic regression. Receiver operating characteristic analysis was performed to determine the optimal Spinal Deformity Study Group index cut-off value. All patients were followed up for at least 2 years.

Results

The scoliosis group comprises 36 patients (mean age: 9.6 ± 2.7 years), while the no scoliosis group comprises 20 (mean age: 9.1 ± 2.4 years). Slip percentage and Spinal Deformity Study Group index were significantly higher in the scoliosis group (p < 0.01). Sacral slope and pelvic incidence were lower in the scoliosis group (p < 0.05). Univariate logistic regression analysis showed that slip percentage, Spinal Deformity Study Group index, pelvic incidence, and sacral slope were significantly associated with scoliosis. In the multivariate logistic regression analysis, only Spinal Deformity Study Group index was an independent risk factor for scoliosis. The optimal cut-off value for Spinal Deformity Study Group index was 0.288. Mean Cobb angle decreased from 20.3° ± 8.8° before surgery to 8.5° ± 8.9° at last follow-up; the mean scoliosis correction rate was 59.3%.

Conclusion

Severe S1 dysplasia and high slip percentage may be risk factors for developing scoliosis in patients with dysplastic spondylolisthesis. Scoliosis resolved spontaneously after spondylolisthesis reduction and fixation in most patients.

Level of evidence

3.

Relationship between gait parameter and spinal sagittal profiles in asymptomatic subjects

BACKGROUND

To study the gait parameters in asymptomatic volunteers and investigate the correlation between the gait and several radiographic sagittal profiles.

METHODS

Asymptomatic volunteers (20-50 years of age) were included and allocated into three subgroups depending on pelvic incidence (low, normal, and high). Standing whole spine radiographs and gait analysis data were obtained. The Pearson Coefficient Correlation was used to determine the relationship between the gait and radiographic profiles.

RESULTS

A total of 55 volunteers (28 male and 27 females) were included. The mean age was 27.35 ± 6.37 years old. The average sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and PI-LL mismatch (PI-LL) were 37.78 ± 6.59, 14.51 ± 9.19 degrees, and 52.29 ± 10.87 degrees and - 0.36 ± 11.41, respectively. The mean velocity and stride of all the volunteers were 119.00 ± 30.12 cm/s and 130.25 ± 7.72 cm, correspondingly. The correlation between each of the radiographical and gait parameters was low (ranging from - 0.24 to 0.26).

CONCLUSION

Gait parameters were not differenced significantly between each of the PI subgroups in asymptomatic volunteers. Spinal sagittal parameters also showed a low correlation with gait parameters.

Age, pelvic incidence, facet joint angle and pedicle-facet angle as correlative factors for isthmic spondylolisthesis: a retrospective case control study

BACKGROUND

Isthmic spondylolisthesis (IS) is a common clinical disease with a high incidence rate. However, most current researches explain the clear pathogenesis from a single perspective. The aim of our study was to explore the relationships between multiple parameters in patients and find the potential risk factors of this disease.

METHODS

Our study retrospectively included 115 patients who were diagnosed with isthmic spondylolisthesis and the same number of individuals without spondylolisthesis. The following parameters were measured or collected: age, pelvic incidence (PI), facet joint angle (FJA) and pedicle-facet angle (P-F angle). The radiographic files were imported into Mimics Medical 20.0 and all collected data were analyzed using SPSS, version 26.0, statistical software.

RESULTS

The age was higher in IS group than in control group. PI was also higher in the IS group (50.99 ± 7.67) than in the control group (43.77 ± 9.30) significantly (P = 0.009). There was significant difference in cranial and average FJA tropism in L3-L4 level (P = 0.002, P = 0.006, respectively) and in L4-L5 level (P < 0.001). P-F angle of L4-L5 level showed significantly larger in IS group than in control group (P = 0.007).The logistic regression analysis showed a larger age, a greater L3-L4 cranial FJA tropism, and a greater L4-L5 cranial FJA tropism were potential predictors of IS, with an OR of 1.07, 1.28, and 1.39 respectively. The thresholds of the predictors were 60 years, 5.67°, and 8.97° according to the ROC curve. The linear regression equation was established: degree of slippage (%) = 0.220*age - 0.327* L3-4 cranial FJA tropism - 0.346* L4-5 average FJA tropism (F = 3.460, P = 0.011, r = 0.659).

CONCLUSIONS

Our study revealed that isthmic spondylolisthesis may be related to multiple factors rather than a single factor. Age, PI, PJA and P-F angle are potentially associated with spondylolisthesis.

Impact of Individual Spinopelvic Anatomy on the Localization and Severity of Symptomatic Isthmic Spondylolisthesis

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVES

Isthmic spondylolisthesis (iSPL) occurs most commonly in L5/S1 and L4/5. This study investigates the association between spinopelvic anatomy and the pathogenesis of iSPL.

METHODS

Spinopelvic parameters as well as severity of slip grade were measured in sagittal spine radiographs of symptomatic patients with iSPL in segments L4/5 and L5/S1. Means were calculated and differences between both groups were analyzed. A correlation between the analyzed parameters and degree of slippage was performed.

RESULTS

We included 73 subjects in this study; 11 in L4/5 group and 62 in L5/S1 group. Pelvic anatomy significantly differed between L4/5 and L5/S1 iSPL (Pelvic Incidence (PI) 54.8° vs 66.3°, P value = .006; Pelvic Radius (PR) 124.4 mm vs 137.4 mm; P value = .005 and Sacral Table Angle (STA) 101.0° vs 92.2°, P value < .001). The relative degree of slippage was significantly higher in the L5/S1 group (L4/5 29.1% vs L5/S1 40.1%, P value .022). We also observed a significant correlation between pelvic anatomy and the severity of the slip in iSPL at the L5/S1 level.

CONCLUSIONS

Pelvic parameters PI and STA play an important role concerning the level of occurrence and severity of iSPL. Spinopelvic anatomy determines the pathogenesis of iSPL.

A Review of the Main Classifications of Lumbar Spondylolisthesis

OBJECTIVE

This study was conducted to review the main classifications and to present author's recommendations.

METHODS

Review of English language medical literature.

RESULTS

In recent decades, classification systems of lumbar spondylolisthesis have been proposed based on many factors, from essential causes to combinations of imaging features and clinical manifestations; the latter type of system is more clinically practical. We have systematically listed the main types of classification systems in chronological order to make it easier for clinicians to find the type of diagnosis and treatment suitable for their patients and develop an appropriate treatment plan.

CONCLUSIONS

Classification systems for lumbar spondylolisthesis have been proposed that have been based on the study of the essential causes or the combination of imaging features and clinical manifestations; the latter type of system is more clinically practical. We still have much work to do in exploring a more applicable classification of lumbar spondylolisthesis.

Spine Alignment in Standing and Maximal Upper Limb Elevation in Baseball Players with Lumbar Spondylolysis and Those without Low Back Pain

The changes in lumbar lordosis angle (LL) and sacral slope angle (SS) related to upper limb elevation and thoracic kyphosis angle (TK) in baseball players with spondylolysis remain unclear. Herein, we investigated baseball players with spondylolysis and those without low back pain, comparing LL and SS with upper limb elevation within and between groups and TK between groups. Baseball players with spondylolysis were enrolled as subjects, and baseball players without low back pain were enrolled as controls (n = 8 each). X-rays were obtained in the standing position and with maximal elevation position of the upper limb (elevation position). LL and SS were measured in the standing and elevated positions, and TK was measured in the standing position. LL was significantly larger in individuals with spondylolysis than controls. The SS of the control group was significantly larger in the elevated position than in the standing position, while the SS of the spondylolysis group was not significantly different between positions. SS was significantly larger in the spondylolysis group than in the control group, only in the standing position. Physical therapy for spondylolysis should focus on hyperlordosis alignment in the standing and maximal elevation positions of both upper limbs, sacral hyper-slope alignment in the standing position, and decreased sacral slope motion.

The relationship between spino-pelvic alignment and primary dysmenorrhea

Introduction

Most women of reproductive age suffered from the primary dysmenorrhea (PD). Up to date, most studies on the etiology of dysmenorrhea focused on endocrine factors while ignored the effect of spino-pelvic bony anatomy on uterus. In this study, we innovatively shed light on the relationship between primary dysmenorrhea and sagittal spino-pelvic alignment.

Materials and Methods

120 patients diagnosed with primary dysmenorrhea and a control group of 118 healthy volunteers were enrolled into this study. All subjects received the standing full-length posteroanterior plain radiography to evaluate the sagittal spino-pelvic parameters. The visual analog scale (VAS) was used to assess pain rating of primary dysmenorrhea patients. Analysis of variance (ANOVA) or Student's t test was performed to measure statistical significance between differences.

Results

There was a significant difference in pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL) and thoracic kyphosis (TK) between PD group and Normal group (P<0.05). Furthermore, in PD group, the PI and SS was significant different between mild pain group and moderate pain group (P<0.05) and there was a significant negative correlation between pain rating and SS. From the perspective of sagittal spinal alignment, the majority of PD patients were classified with Roussouly type 2, meanwhile most normal people were classified with Roussouly type 3.

Conclusion

Sagittal spino-pelvic alignment was related to primary dysmenorrhea symptoms. Lower SS and PI angles may contribute to a worsen pain in PD patients.

Surgical management of high-grade paediatric spondylolisthesis: meta-analysis and systematic review

PURPOSE

There is currently no consensus on the management of high-grade spondylolisthesis (HGS) in paediatric populations. The objective of this analysis is to compare the outcomes of reduction followed by fusion (RFF) or in situ fusion (ISF) in paediatric patients.

METHODS

Using major databases, a systematic literature search was performed. Primary studies comparing ISF with RFF in paediatric and adolescent patients were identified. Study data including patient-reported outcomes, complications, and spinopelvic parameters were collected and analysed.

RESULTS

Seven studies were included, comprising 97 ISF and 131 RFF. Average patient age was 14.4 ± 2.1 years and follow up was 8.2 ± 5.1 years. Patients undergoing RFF compared to patients undergoing ISF alone were less likely to develop pseudarthrosis (RR 0.51, 95% CI, [0.26, 0.99], p = 0.05). On average, RFF led to 11.97º more reduction in slip angle and 34.8% more reduction in sagittal translation (p < 0.00001) compared to ISF. There was no significant difference between patient satisfaction and pain at follow up. Neurologic complications and reoperation rates were not significantly different.

CONCLUSIONS

Both RFF and ISF are effective techniques for managing HGS. Performing a reduction followed by fusion reduces the likelihood of pseudarthrosis in paediatric patients. The difference between risk of neurologic complications, need for reoperation, patient satisfaction, and pain outcomes did not reach statistical significance. Correlation with patient-reported outcomes still needs to be further explored. LEVEL 3 EVIDENCE: Meta-analysis of Level 3 studies.

Alignment of the Sternum and Sacrum as a Marker of Sitting Body Posture in Children

An analysis of literature on the methods of assuming a sitting position and the results of our own research indicated the need to search for biomechanical parameters and existing relationships that would enable a description of sitting body posture. The purpose of this paper is to analyze the relationship between the alignment of the body of sternum and sacrum and the changes in the thoracic and lumbar spine curvatures in children. The study involved 113 subjects aged 9-13 years. A planned simultaneous measurement of the angle parameters of the alignment of the body of sternum and sacrum relative to the body's sagittal axis and the angle parameters of the thoracic and lumbar spine curvatures was performed during a single examination session. The proposed markers of alignment in the corrected sitting body posture are characterized by homogeneous results. A high measurement repeatability was observed when determining the corrected body posture in the study setting. It was noted that changes in the alignment of the body of sternum and sacrum resulted in changes in the thoracic kyphosis and lumbar lordosis angle values, which may be an important component of clinical observations of sitting body posture in children. Implementing the body of sternum alignment angle of about 64° relative to the body's sagittal axis in clinical practice as one of the objectives of postural education may be the target solution for sitting body posture correction in children.

Efficacy of transforaminal lumbar interbody fusion in the treatment of double-level lumbar spondylolisthesis with sagittal imbalance

OBJECTIVE

To analyze the clinical efficacy of transforaminal lumbar interbody fusion (TLIF) in the treatment of continuous double-level lumbar spondylolisthesis with sagittal imbalance.

METHODS

The clinical data of 36 patients with double-level spondylolisthesis treated with TLIF were included and divided into L3/L4 double spondylolisthesis group and L4/L5 double spondylolisthesis group according to the site of spondylolisthesis. The sagittal parameters of the patients were measured by standing anteroposterior and lateral X-rays of the whole spine, and the visual analogue scale (VAS) for lumbar and lower limb pain, Japanese Orthopaedic Association (JOA), and Oswestry Disability Index (ODI) were recorded. The imaging parameters and clinical parameters of the patients before surgery, after surgery, and at the last follow-up were compared and statistically analyzed.

RESULTS

A total of 36 patients were included in the study and all had sagittal imbalance. Among them, there were 21 cases of L3 and L4 spondylolisthesis, 6 males and 15 females, with an average age of 64.7 ± 9.4 years; there were 15 cases of L4 and L5 spondylolisthesis, 4 males and 11 females, with an average age of 66.5 ± 8.0 years. 36 patients completed the operation, the operation time was 190.28 ± 6.12 min, and intraoperative blood loss was 345 ± 11 ml. Compared with preoperative, there were significant differences in SVA, TPA, T1-SPi, LL, PT, SS, PI-LL, SD, SA, and SP between patients after surgery and at the last follow-up (P < 0.05). Compared with preoperative, VAS score, JOA score, and ODI index of waist and lower limbs were significantly improved after the operation and at the last follow-up, and there was a significant difference (P < 0.05).

CONCLUSION

TLIF can effectively relieve the symptoms of patients with continuous double-level lumbar spondylolisthesis, restore lumbar lordosis and sagittal spinal sequence, and improve the quality of life of patients.

Classification(s) of Cervical Deformity

Cervical spine deformities (CSD) are complex surgical issues with currently heterogenous management strategies. The classification of CSD is still an evolving field. Rudimentary classification schemas were initially proposed in the late 20th century but were largely informal and based on the underlying etiology (i.e. , postsurgical, traumatic, or inflammatory). The first formal classification schema was proposed by Ames et al. in 2015 who established a standard nomenclature for describing these deformities. This classification system established 5 deformity descriptors based on curve apex location (cervical, cervicothoracic, thoracic, craniovertebral junctional, and coronal deformities) and 5 deformity modifiers which helped surgeons utilize a standard language when discussing CSD patients. Koller et al. in 2019 subsequently established a classification system for patients with rigid cervical kyphosis based on regional and global sagittal alignment. Most recently, Kim et al. in 2020 proposed an updated classification system utilizing dynamic cervical spine imaging to guide surgical treatment of CSD patients. It identified 4 major groups of deformities - (1) those with "flat-neck" deformities caused by cervical lordosis T1 slope mismatch; (2) those with focal kyphotic deformities between 2 cervical vertebrae; (3) those with cervicothoracic deformities caused by large T1 slope; and (4) those with coronal deformities. Group 2 deformities most often required combined anterior-posterior approaches with short constructs, and group 3 deformities most often required posterior-only approaches with 3-column osteotomies.

Classification system for cervical spine deformity morphology: a validation study

OBJECTIVE

The objective of this study was to initially validate a recent morphological classification of cervical spine deformity pathology.

METHODS

The records of 10 patients for each of the 3 classification subgroups (flat neck, focal deformity, and cervicothoracic), as well as for 8 patients with coronal deformity only, were extracted from a prospective multicenter database of patients with cervical deformity (CD). A panel of 15 physicians of various training and professional levels (i.e., residents, fellows, and surgeons) categorized each patient into one of the 4 groups. The Fleiss kappa coefficient was utilized to evaluate intra- and interrater reliability. Accuracy, defined as properly selecting the main driver of deformity, was reported overall, by morphotype, and by reviewer experience.

RESULTS

The overall classification demonstrated a moderate to substantial agreement (round 1: interrater Fleiss kappa = 0.563, 95% CI 0.559-0.568; round 2: interrater Fleiss kappa = 0.612, 95% CI 0.606-0.619). Stratification by level of training demonstrated similar mean interrater coefficients (residents 0.547, fellows 0.600, surgeons 0.524). The mean intrarater score was 0.686 (range 0.531-0.823). A substantial agreement between rounds 1 and 2 was demonstrated in 81.8% of the raters, with a kappa score > 0.61. Stratification by level of training demonstrated similar mean intrarater coefficients (residents 0.715, fellows 0.640, surgeons 0.682). Of 570 possible questions, reviewers provided 419 correct answers (73.5%). When considering the true answer as being selected by at least one of the two main drivers of deformity, the overall accuracy increased to 86.0%.

CONCLUSIONS

This initial validation of a CD morphological classification system reiterates the importance of dynamic plain radiographs for the evaluation of patients with CD. The overall reliability of this CD morphological classification has been demonstrated. The overall accuracy of the classification system was not impacted by rater experience, demonstrating its simplicity.

Is quality of life after surgery for adolescent idiopathic scoliosis affected by the presence of a concomitant low-grade isthmic spondylolisthesis non-surgically treated? A retrospective cohort study

PURPOSE

The HRQoL after surgery for adolescent idiopathic scoliosis (AIS) is not affected by the presence of concomitant isthmic spondylolisthesis non-surgically treated. Improvement in QoL after surgery was similar for AIS patients with and without concomitant spondylolisthesis. The purpose is to compare preoperative and postoperative Health-Related Quality of Life (HRQoL) scores in operated AIS patients with and without concomitant isthmic spondylolisthesis.

METHODS

A retrospective study of a prospective cohort of 464 individuals undergoing AIS surgery between 2008 and 2018 was performed. All patients undergoing surgery for AIS with a minimum 2-year follow-up were included. We excluded patients with prior or concomitant surgery for spondylolisthesis. HRQoL scores were measured using the SRS-22 questionnaire. Comparisons were performed between AIS patients with versus without concomitant spondylolisthesis treated non-surgically.

RESULTS

AIS surgery was performed for 36 patients (15.2 ± 2.5 y.o) with concomitant isthmic spondylolisthesis, and 428 patients (15.5 ± 2.4 y.o) without concomitant spondylolisthesis. The two groups were similar in terms of age, sex, preoperative and postoperative Cobb angles. Preoperative and postoperative HRQoL scores were similar between the two groups. HRQoL improved significantly for all domains in both groups, except for pain in patients with spondylolisthesis. There was no need for surgical treatment of the spondylolisthesis and no slip progression during the follow-up duration after AIS surgery.

CONCLUSION

Patients undergoing surgical treatment of AIS with non-surgical management of a concomitant isthmic grade I spondylolisthesis can expect improvement in HRQoL scores, similar to that observed in patients without concomitant spondylolisthesis.

Comparison of alignment and spondylolysis fracture angle in bilateral and unilateral spondylolysis

OBJECTIVES

Spondylolysis occurs bilaterally or unilaterally and bilateral spondylolysis increases the risk of developing isthmic spondylolisthesis. The characteristics of the lumbar lordosis angle (LLA), sacral slope angle (SSA), and spondylolysis fracture angle (SFA) in bilateral spondylolysis compared with those in unilateral spondylolysis have not been clarified. The purpose of this study was to compare the LLA, SSA, and SFA of bilateral and unilateral spondylolysis.

MATERIALS AND METHODS

Thirty-eight patients with lumbar spondylolysis who visited our clinic for an initial visit and 15 age-matched patients with a chief complaint of low back pain were included as controls. Computed tomography films were used to classify all spondylolysis patients into two groups: those with bilateral fractures (bilateral) and those with unilateral fractures (unilateral). The LLA and SSA were measured using lateral X-ray films and the SFA was measured using computed tomography films.

RESULTS

The LLA was significantly higher in all spondylolysis patients than in the control group (p = .026). There was no significant difference in SSA between the spondylolysis and control groups (p = .28). The LLA was significantly higher in the bilateral group than in the unilateral group (p = .018). There was no significant difference in SSA between the bilateral and unilateral groups (p = .15). The SFA was significantly lower in the bilateral group than in the unilateral group (p = .024).

CONCLUSIONS

This study suggests that physical therapy for spondylolysis may be considered bilaterally and unilaterally.

Direct Pars Repair with Cannulated Screws in Adults: A Case Series and Systematic Literature Review

OBJECTIVE

Lumbar spondylolysis occurs in 5%-8% of adults. This study aimed to report clinical and radiographic outcomes of direct pars repair in adults with lumbar spondylolysis.

METHODS

We conducted a retrospective review of all patients treated for lumbar spondylolysis via open fracture reduction and direct pars repair with cannulated screws using a lag technique. Demographics, clinical presentation, perioperative and intraoperative imaging, and postoperative data were collected. We subsequently performed a systematic review to describe radiographic and clinical outcomes following direct pars repair.

RESULTS

Three patients were identified (mean age 40.3 years; range, 21-72 years; 2 male). All patients had bilateral L5 pars fractures treated via open, direct repair with cannulated screws. There were no intraoperative complications. Length of stay was <24 hours for each patient. All patients reported back/radicular symptom relief and returned to full-time manual labor by latest follow-up. Noncontrast lumbar computed tomography performed 14-20 months postoperatively confirmed that all patients had good bilateral screw placement without fracture. Two patients (21 and 28 years old at surgery) had evidence of fusion across fracture sites, while 1 patient exhibited radiolucency around the screws and no progression of spondylolisthesis. Additionally, we reviewed 8210 articles and included 15 in a systematic review of direct pars repair. Fusion rates were 67%-100%, with improved average Oswestry Disability Index and visual analog scale back pain scores by latest follow-up.

CONCLUSIONS

Lumbar spondylolysis treatment with open fracture reduction and direct pars repair with cannulated screws in adults is safe and may result in mechanical back/radicular pain relief, even in the absence of radiographic fusion.

Long-term Radiological and Clinical Outcome after Lumbar Spinal Fusion Surgery in Patients with Degenerative Spondylolisthesis: A Prospective 6-Year Follow-up Study

Objective

To assess which radiological alignment parameters are associated with a satisfactory long‐term clinical outcome after performing lumbar spinal fusion for treating degenerative spondylolisthesis.

Methods

This single‐center prospective study assessed the relation between radiological alignment parameters measured on standing lateral lumbar spine radiographs and the patient‐reported outcome using four different questionnaires (COMI, EQ‐5D, ODI and VAS) as primary outcome measures (level of evidence: II). The following spinopelvic alignment parameters were used: gliding angle, sacral inclination, anterior displacement, sagittal rotation, lumbar lordosis, sacral slope, pelvic tilt and pelvic incidence. Furthermore, the length of stay and perioperative complications were documented. Only cases from 2013 to 2015 of low‐grade degenerative lumbar spondylolisthesis (Meyerding grades I and II) were considered. The patients underwent open posterior lumbar fusion surgery by pedicle screw instrumentation and cage insertion. The operative technique was either a posterior lumbar interbody fusion (PLIF) or a transforaminal lumbar interbody fusion (TLIF) performed by three different senior orthopedic surgeons. Exclusion criteria were spine fractures, minimally invasive techniques, underlying malignant diseases or acute infections, previous or multisegmental spine surgery as well as preoperative neurologic impairment. Of 89 initially contacted patients, 17 patients were included for data analysis (11 males, six females).

Results

The data of 17 patients after mono‐ or bisegmental lumbar fusion surgery to treat low‐grade lumbar spondylolisthesis and with a follow‐up time of least 72 months were analyzed. The mean age was 66.7 ± 11.3 years. In terms of complications two dural tears and one intraoperative bleeding occurred. The average body mass index (BMI) was 27.6 ± 4.4 kg/m² and the average inpatient length of stay was 12.9 ± 3.8 days (range: 8–21). The long‐term clinical outcome correlated significantly with the change of the pelvic tilt (r_s = −0.515, P < 0.05) and the sagittal rotation (r_s = −0.545, P < 0.05). The sacral slope was significantly associated with the sacral inclination (r_s = 0.637, P < 0.01) and the pelvic incidence (r_s = 0.500, P < 0.05). In addition, the pelvic incidence showed a significant correlation with the pelvic tilt (r_s = 0.709, P < 0.01). The change of the different clinical scores over time also correlated significantly between the different questionnaires.

Conclusions

The surgical modification of the pelvic tilt and the sagittal rotation are the two radiological alignment parameters that can most accurately predict the long‐term clinical outcome after lumbar interbody fusion surgery.

Efficacy of Single-Position Oblique Lateral Interbody Fusion Combined With Percutaneous Pedicle Screw Fixation in Treating Degenerative Lumbar Spondylolisthesis: A Cohort Study

Objective

To investigate the surgical outcomes of single-position oblique lateral interbody fusion (OLIF) combined with percutaneous pedicle screw fixation (PPSF) in treating degenerative lumbar spondylolisthesis (DLS).

Methods

We retrospectively analyzed 85 patients with DLS who met the inclusion criteria from April 2018 to December 2020. According to the need to change their position during the operation, the patients were divided into a single-position OLIF group (27 patients) and a conventional OLIF group (58 patients). The operation time, intraoperative blood loss, hospitalization days, instrumentation accuracy and complication rates were compared between the two groups. The visual analog scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical efficacy. The surgical segment's intervertebral space height (IDH) and lumbar lordosis (LL) angle were used to evaluate the imaging effect.

Results

The hospital stay, pedicle screws placement accuracy, and complication incidence were similar between the two groups (P > 0.05). The operation time and intraoperative blood loss in the single-position OLIF group were less than those in the conventional OLIF group (P < 0.05). The postoperative VAS, ODI, IDH and LL values were significantly improved (P < 0.05), but there was no significant difference between the two groups (P > 0.05).

Conclusions

Compared with conventional OLIF, single-position OLIF combined with PPSF is also safe and effective, and it has the advantages of a shorter operation time and less intraoperative blood loss.

Influence of Sagittal Lumbopelvic Morphotypes on the Range of Motion of Human Lumbar Spine: An In Vitro Cadaveric Study

Background: Although spinopelvic radiographs analysis is the standard for a pathological diagnosis, it cannot explain the activities of the spine in daily life. This study investigates the correlation between sagittal parameters and spinal range of motion (ROM) to find morphological parameters with kinetic implications. Methods: Six L1–S1 human lumbar specimens were tested with a robotic testing device. Eight sagittal parameters were measured in the three-dimensional model. Pure moments were applied to simulate the physiological activities in daily life. Results: The correlation between sagittal parameters and the ROM was moderate in flexion and extension, but weak in lateral bending and rotation. In flexion–extension, the ROM was moderately correlated with SS and LL. SS was the only parameter correlated with the ROM under all loading conditions. The intervertebral rotation distribution showed that the maximal ROM frequently occurred at the L5–S1 segment. The minimal ROM often appeared near the apex point of the lumbar. Conclusion: Sagittal alignment mainly affected the ROM of the lumbar in flexion and extension. SS and apex may have had kinetic significance. Our findings suggest that the effect of sagittal parameters on lumbar ROM is important information for assessing spinal activity.

Does minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) influence functional outcomes and spinopelvic parameters in isthmic spondylolisthesis?

PURPOSE

We assessed the efficacy of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in patients with low-grade isthmic spondylolisthesis.

METHODS

We included 24 symptomatic patients who underwent MIS-TLIF between December 2017 and December 2020. Patients were followed up clinically by the Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) for back and VAS for leg pain, as well as radiological radiographs after 6 weeks, 6 months, and at final follow-up (at least 12 months). Measured parameters included C7 sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), Meyerding slip grades, lumbar lordosis (LL), L1-L4 angle, L4-S1 angle, and segmental lordosis (SL) of the affected segment. The mismatch between the PI and LL was also measured.

RESULTS

VAS for back, VAS for leg pain, and ODI significantly improved postoperatively (all p < 0.001). We observed significantly decreased mean values of PT and slip percentage and increased mean values of SS and LL (all p < 0.05). We observed a significant reduction in L1-L4 lordosis and a significant increase in L4-S1 lordosis. The final PT, SS, and LL (total and L1-L4) were significantly higher in group III patients (n = 15) than the values of group II patients (n = 9). None of the patients became unbalanced postoperative, and all patients had a normal matching between the PI and the LL postoperatively.

CONCLUSIONS

MIS-TLIF is a safe procedure for managing low-grade isthmic spondylolisthesis with significant improvement in clinical and radiological outcomes. It can correct and maintain a proper spinopelvic alignment.

Transverse Pedicle Angle Is Associated With Pelvic Incidence and Increased in Lumbar Isthmic Spondylolisthesis

STUDY DESIGN

Retrospective radiographic review.

OBJECTIVES

Investigate and quantify transverse pedicle angle (TPA), the medial-to-lateral pedicle angulation, and its potential association with pelvic incidence (PI) in patients with isthmic lumbar spondylolisthesis (ISLS) and compare to those with degenerative lumbar spondylolisthesis (DSLS) and controls.

METHODS

A total of 200 patients (64 ISLS, 70 DSLS, 66 control) were included. TPA was calculated at the L3-5 vertebral levels using axial computed tomography slices. PI was measured on lateral radiographs. Two independent observers completed the measurements. As a sensitivity analysis, TPA was also measured at the most cranial and caudal aspects of the L3-5 vertebral levels of a subset of participants (29 ISLS, 31 DSLS, 35 control) and the cranial to caudal change (ΔTPA) was calculated.

RESULTS

TPA values (mean ± SD) at L4 and L5 for ISLS (L4: 17.3° ± 3.7°, L5: 26.0° ± 5.2°) were significantly higher than those for the DSLS (L4: 14.3° ± 3.8°, L5: 22.2° ± 5.0°) and control (L4: 14.5° ± 3.9°, L5: 20.7° ± 3.8°) groups. TPA in the DSLS group was significantly higher than controls at L5, but not L4. High PI predicted wider TPA at L5 in both DSLS and ISLS. ΔTPA (mean ± SD) increased sequentially proceeding through the L3-5 spinal levels for the ISLS (L3: 6.8° ± 4.4°, L4: 8.7° ± 5.2°, L5: 15.6° ± 9.0°), DSLS (L3: 8.2° ± 6.0°, L4: 8.3° ± 5.9°, L5: 18.3° ± 7.2°), and control (L3: 6.8° ± 4.4°, L4: 8.2° ± 4.7°, L5: 17.7° ± 7.0°) groups.

CONCLUSIONS

TPA was significantly increased in ISLS compared with DSLS and controls. High PI significantly predicted high TPA at the L5 vertebral level in ISLS and DSLS. ΔTPA increased sequentially proceeding through the lumbar spine across groups.

Surgical outcomes with anatomic reduction of high-grade spondylolisthesis revisited: an analysis of 101 patients

OBJECTIVE

The ideal strategy for high-grade L5-S1 isthmic spondylolisthesis (HGS) remains controversial. Critical questions include the impact of reduction on clinical outcomes, rate of pseudarthrosis, and postoperative foot drop. The scope of this study was to delineate predictors of radiographic and clinical outcome factors after surgery for HGS and to identify risk factors of foot drop.

METHODS

This was a single-center analysis of patients who were admitted for HGS, defined as grade III or greater L5 translation according to the Meyerding (MD) classification. Complete postoperative reduction was defined as MD grade I or less and L5 slip < 20%. Forty-six patients completed health-related quality-of-life questionnaires (Oswestry Disability Index, Physical Component Summary of SF-36, and visual analog scale) and ≥ 2 years' follow-up (average 105 months). A 540° approach was used in 61 patients, a 360° approach was used in 40, and L5 corpectomy was used in 17. Radiographic analysis included measures of global spinopelvic balance (e.g., pelvic incidence [PI], lumbar lordosis) and measurement of lumbosacral kyphosis angle (LSA), L4 slope (L4S), L5 slip (%), and postoperative increase of L5-S1 height.

RESULTS

The authors included 101 patients with > 1 year of clinical and radiographic follow-up. The mean age was 26 years. Average preoperative MD grade was 3.8 and average L5 slip was 81%; complete reduction was achieved in 55 and 42 patients, respectively, according to these criteria. At follow-up, LSA correlated with all clinical outcomes (r ≥ 0.4, p < 0.05). Forty patients experienced a major complication. Risk was increased in patients with greater preoperative deformity (i.e., LSA) (p = 0.04) and those who underwent L5 corpectomy (p < 0.01) and correlated with greater deformity correction. Thirty-one patients needed revision surgery, including 17 for pseudarthrosis. Patients who needed revision surgery had greater preoperative deformity (i.e., MD grade and L5 slip) (p < 0.01), greater PI (p = 0.02), and greater postoperative L4S (p < 0.01) and were older (p = 0.02), and these patients more often underwent L5 corpectomy (p < 0.01). Complete reduction was associated with lower likelihood of pseudarthrosis (p = 0.08) and resulted in better lumbar lordosis correction (p = 0.03). Thirty patients had foot drop, and these patients had greater MD grade and L5 slip (p < 0.01) and greater preoperative LSA (p < 0.01). These patients with foot drop more often required L5 corpectomy (p < 0.01). Change in preoperative L4S (p = 0.02), LSA (p < 0.01), and L5-S1 height (p = 0.02) were significantly different between patients with foot drop and those without foot drop. A significant risk model was established that included L4S change and PI as independent variables and foot drop as a dependent variable (82% negative predictive value and 71% positive predictive value, p < 0.01).

CONCLUSIONS

Multivariable analysis identified factors associated with foot drop, major complications, and need for revision surgery, including degree of deformity (MD grade and L5 slip) and correction of LSA. Functional outcome correlated with LSA correction.

[Lumbo-pelvino-acetabular alignment-basics and clinical consequences]

The spinal shape and the pelvic ante-/retroversion of an individual are determined by its innate, genetically fixed lumbosacral angulation. This can be measured with little effort in the lateral standing radiograph of the patient. In spinal surgery, there are a lot of original papers on the topic. In hip surgery, however, the individual pelvic version and its consequences for the acetabular orientation have not received the same attention so far.This review focuses on previous data on the relationship between lumbosacral angulation and pelvic ante-/retroversion. Four anatomically definable pelvic types can be distinguished; three of those have to be considered as facultatively pathogenetic. Clinical consequences arise for the clinical pictures of spondylolisthesis, non-specific lower back pain, acetabular retroversion and developmental dysplasia of the hip, as well as for acetabular cup positioning in total hip arthroplasty.

PRE- AND POSTOPERATIVE COMPARATIVE ANALYSIS OF THE SPINOPELVIC AND GLOBAL SAGITTAL PARAMETERS OF PATIENTS WITH ADOLESCENT IDIOPATHIC SCOLIOSIS

ABSTRACT Objective: To analyze the pre- and postoperative spinopelvic parameters and global sagittal balance of patients with adolescent idiopathic scoliosis (AIS) divided into 3 groups (Group 1 – thoracic arthrodesis, Group 2 - thoracolumbar arthrodesis, and Group 3 – lumbar arthrodesis), observing differences in these two moments and whether the parameter values are maintained or not over a period of up to 2 years following surgery. Methods: We analyzed the radiographs from a single-center database of 99 patients who underwent arthrodesis with posterior instrumentation. Pelvic incidence, pelvic version, sacral slope, lumbar lordosis, thoracic kyphosis, and sagittal vertical axis values were measured in the pre- and postoperative radiographies of each patient. Results: The parameters of pelvic incidence, pelvic version, sacral slope, and sagittal vertical axis did not show statistically significant differences among the 3 groups. There was a difference in preoperative lumbar lordosis between the 3 groups (p = 0.049). Thoracic kyphosis showed differences both in the pre- (p = 0.015) and postoperative (p = 0.042) values, in addition to demonstrating a relationship of dependence between the pre- and postoperative values in the final statistical analysis. Conclusion: The evaluation of the parameters analyzed shows that the study groups have similar values of individual balance, with the exception of thoracic kyphosis and lumbar lordosis, which are measurements that depend on the surgical technique and compensatory mechanisms, but remained within normal ranges. These factors allow the surgeon to be attentive to both the coronal and sagittal planes when planning the correction in order to achieve the equilibrium of the trunk in addition to correction of the deformity. Level of Evidence IIIA: Comparative retrospective study.

Prevalence of Incidentally Detected Spondylolysis in Children

Purpose

To assess the prevalence of incidentally detected lumbar spondylolysis in children.

Materials and Methods

We retrospectively reviewed the data of 809 patients under the age of 11 years (mean age, 7.0 ± 2.7 years; boys:girls = 479:330) who underwent abdominal and pelvic CT between March 2014 and December 2018. We recorded the presence, level, and laterality (unilateral or bilateral) of spondylolysis. Patients were divided into two groups based on the presence of spondylolysis: the spondylolysis (SP) and non-SP groups.

Results

In total, 21 cases of spondylolysis were detected in 20 patients (20/809, 2.5%). The mean age of the SP group was higher than that of the non-SP group (7.8 ± 1.8 vs. 6.9 ± 2.7 years, p > 0.05). The prevalence of spondylolysis in boys was higher than that in girls (15/479 [3.1%] vs. 5/330 [1.5%], p > 0.05). The prevalence of spondylolysis in school-age children (6–10 year olds) was higher than that in preschool-age children (0–5 year olds) (17/538 [3.2%] vs. 3/271 [1.1%], p > 0.05). L5 was the most common level of spondylolysis (76.2%); one 8-year-old boy had twolevel spondylolysis. One case of isthmic spondylolisthesis was detected in a 10-year-old boy (1/809, 0.1%). There were 11 unilateral spondylolysis cases (11/21, 52.4%).

Conclusion

In our study, the prevalence of spondylolysis in children under the age of 11 was 2.5%. The prevalence was higher in boys than in girls and in school-age than in preschool-age children, despite the lack of any statistically significant differences.

Biomechanical analysis of reduction technique for lumbar spondylolisthesis: anterior lever versus posterior lever reduction method

BACKGROUND

Reduction of lumbar spondylolisthesis during spinal fusion surgery is important for improving the fusion rate and restoring the sagittal alignment. Despite the variety of reduction methods, the fundamental mechanics of lumbar spondylolisthesis reduction remain unclear. This study aimed to investigate the biomechanical behavior while performing spondylolisthesis reduction with the anterior and posterior lever reduction method.

METHODS

We developed an L4-L5 spondylolisthesis model using sawbones. Two spine surgeons performed the simulated reduction with a customized Cobb elevator. The following data were collected: the torque and angular motion of Cobb, displacement of vertebral bodies, change of lordotic angle between L4 and L5, total axial force and torque applied on the model, and force received by adjacent disc.

RESULTS

Less torque value (116 N-cm vs. 155 N-cm) and greater angular motion (53o vs. 38o) of Cobb elevator were observed in anterior lever reduction. Moreover, the total axial force received by the entire model was greater in the posterior lever method than that in the anterior lever method (40.8 N vs. 16.38 N). Besides, the displacement of both vertebral bodies was greater in the anterior lever method.

CONCLUSIONS

The anterior lever reduction is a more effort-saving method than the posterior lever reduction method. The existing evidence supports the biomechanical advantage of the anterior reduction method, which might be one of the contributing factors to successfully treating high-grade lumbar spondylolisthesis with short-segment instrumentation.

The evolution of pelvic canal shape and rotational birth in humans

BACKGROUND

The human foetus typically needs to rotate when passing through the tight birth canal because of the complex shape of the pelvis. In most women, the upper part, or inlet, of the birth canal has a round or mediolaterally oval shape, which is considered ideal for parturition, but it is unknown why the lower part of the birth canal has a pronounced anteroposteriorly oval shape.

RESULTS

Here, we show that the shape of the lower birth canal affects the ability of the pelvic floor to resist the pressure exerted by the abdominal organs and the foetus. Based on a series of finite element analyses, we found that the highest deformation, stress, and strain occur in pelvic floors with a circular or mediolaterally oval shape, whereas an anteroposterior elongation increases pelvic floor stability.

CONCLUSIONS

This suggests that the anteroposterior oval outlet shape is an evolutionary adaptation for pelvic floor support. For the pelvic inlet, by contrast, it has long been assumed that the mediolateral dimension is constrained by the efficiency of upright locomotion. But we argue that the mediolateral elongation has evolved because of the limits on the anteroposterior diameter imposed by upright posture. We show that an anteroposteriorly deeper inlet would require greater pelvic tilt and lumbar lordosis, which compromises spine health and the stability of upright posture. These different requirements of the pelvic inlet and outlet likely have led to the complex shape of the pelvic canal and to the evolution of rotational birth characteristic of humans.

L5 Radiculopathy After Formal Reduction of High-Grade SDSG Type 5 and 6 L5-S1 Isthmic Spondylolisthesis with 2-Year Follow-Up

BACKGROUND

Surgery is the main treatment for patients with high-grade L5-S1 isthmic spondylolisthesis, which can result in neurologic complications, but little is known about its clinical course. The present study evaluated the presence of L5 radiculopathy in high-grade L5-S1 spondylolisthesis in adults in pre- and postoperative periods and after a 2-year follow-up.

METHODS

A series of 16 patients who underwent reduction and instrumented fusion for high-grade 5 and 6 spondylolisthesis between 2018 and 2019 were retrospectively evaluated in the pre- and postoperative periods as well as after 6 weeks, 3 months, 6 months, and 1 and 2 years of follow-up. Clinical and surgical data on possible neurological complications of L5 radiculopathy were prospectively collected.

RESULTS

The age was 20.1 ± 12.0 years, and preoperative L5-S1 slip was 89.0%. Five patients presented motor deficit in the preoperative period. In the immediate postoperative period, 9 patients (56%) experienced motor deficits or worsening of the preoperative condition. At the 6-week follow-up, only 1 patient showed resolution of the motor deficit. Three patients presented healed motor deficits after 3 months, and 1 patient demonstrated a healed L5 motor radiculopathy after 6 months. At the 1-year follow-up, only 1 patient exhibited an L5 radiculopathy motor deficit, and at the 2-year follow-up, none of the patients exhibited an L5 radiculopathy motor deficit.

CONCLUSION

L5 radiculopathy was frequent in the preoperative period and increased after reduction and instrumented fusion of high-grade L5-S1 spondylolisthesis in the postoperative period and in the 6-week follow-up. Three and 6 months after the surgery, there were consecutive motor improvements. After 2 years of follow-up, no patients showed neurological deficit of L5 radiculopathy.

LEVEL OF EVIDENCE

2.

CLINICAL RELEVANCE

This is the first study reporting a reduction in complications of L5 neurological motor deficit over a 2-year follow-up in high-grade L5-S1 spondylolisthesis in young adults.

Comparison of SDSG and CARDS classifications for L5/S1 lumbar degenerative spondylolisthesis: an independent inter- and intra-observer agreement study

BACKGROUND

Lumbar degenerative spondylolisthesis (DS) has been a common disease that makes increasing patients to suffer from different degrees of low back pain and radicular symptoms. The Spinal Deformity Study Group (SDSG) and the Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) systems are commonly used to classify the disease, and help to make a more detailed treatment plan. The objective of this study is to compare the reliability and reproducibility of SDSG and CARDS classifications, and to explore their clinical application value.

METHODS/DESIGN

All 117 patients with L5/S1 lumbar DS were enrolled. Five experienced spine surgeons were selected to assess DS with SDSG and CARDS systems. Kappa (K) value was used to check the coefficient consistency for multi-factor and assess the inter- and intra-observer agreement. After 12 weeks, the analysis was repeated.

RESULTS

The inter-observer reliability and intra-observer reproducibility of SDSG system were substantial with K values of 0.704 and 0.861, while those of CARDS system were substantial with values of 0.620 and 0.878.

CONCLUSION

SDSG system had better inter-observer reliability in comparison with CARDS system, and though CARDS system is more intuitive and simpler, it is more likely to produce deviations when using it. Both SDSG and CARDS systems show substantial agreement and have great significance in surgical strategy of L5/S1 lumbar DS, they can be widely used in clinical practice.

Is There Additional Value to Flexion-Extension Radiographs for Degenerative Spondylolisthesis?

STUDY DESIGN

Multicenter retrospective study.

OBJECTIVE

Flexion-extension radiographs are frequently used to assess motion in patients with degenerative spondylolisthesis. However, they expose patients to additional radiation and increase cost. The aim of this study is to determine if flexion-extension radiographs provide additional information not seen on upright neutral radiographs and supine magnetic resonance imaging (MRI) that may guide surgical decision making.

SUMMARY OF BACKGROUND DATA

Supine MRI and upright neutral radiographs are routinely performed in patients with degenerative spondylolisthesis. It is unclear whether additional flexion-extension views play a significant role in surgical planning for this patient population.

METHODS

From the Quality Outcomes Database, patients who had surgery for grade 1 degenerative spondylolisthesis were identified. Magnitude of slip on pre-op supine MRI, upright neutral, flexion, and extension radiographs were measured. Additional motion was defined as 3 mm or more slip difference between radiographs. For the purpose of this analysis, patients with a slip of 7 mm or more on upright neutral radiographs were assumed to require a fusion.

RESULTS

A total of 191 patients were identified. Mean age was 61.6 years (114 females, 60%). Only 31 patients (16%) had additional motion on flexion-extension views not seen on upright neutral x-rays versus supine MRI. Of these 31 patients, 19 had slips less than 7 mm on upright x-ray, generating equipoise for fusion.

CONCLUSION

Flexion-extension radiographs may play a limited role in management of degenerative spondylolisthesis. The subset of patients for which flexion-extension views were most likely to provide value were patients with smaller slips (<7 mm) with no evidence of motion on standing radiographs versus MRI. In 90% of spondylolisthesis cases, information used for surgical planning may be ascertained by comparing motion between supine MRI and upright lateral radiographs.Level of Evidence: 3.

What is the Optimal Surgical Method for Achieving Correction and Avoiding Neurological Complications in Pediatric High-grade Spondylolisthesis?

BACKGROUND

Controversy persists in the treatment of high-grade spondylolisthesis (HGS). Surgery is recommended in patients with intrusive symptoms and evidence debates the competing strategies. This study compares the radiologic outcomes and postoperative complications at a minimum of 2 years follow-up for patients with HGS treated with instrumented fusion with partial reduction (IFIS) with those treated with reduction, decompression, and instrumented fusion (RIF). We hypothesize that IFIS leads to a lower rate of complication and revision surgery than RIF.

METHODS

A retrospective comparative methodology was used to analyze consecutive HGS treated surgically between 2006 and 2017. Patients diagnosed with ≥grade 3 spondylolisthesis treated with arthrodesis before the age of 18 years with a minimum of 2 years follow-up were included. Patients were excluded if surgery did not aim to achieve arthrodesis or was a revision procedure. Cases were identified through departmental and neurophysiological records.

RESULTS

Thirty patients met the inclusion criteria. Mean follow-up was 4 years. Ten patients underwent IFIS and the remaining 20 underwent RIF. The 2 groups showed no difference in demographics, grade of slip, deformity or presenting symptoms. Of 10 treated with IFIS, the SA reduced by a mean of 10 degrees and C7 sagittal vertical line changed by 31 mm. In the RIF cohort, SA reduced by 16 degrees and C7 sagittal vertical line reduced by 26 mm. PT was unchanged in both groups. In IFIS cohort, 2 patients showed postoperative weakness, resolved by 2 years. None required revision surgery. In the RIF group, 4 sustained dural tears and 1 a laminar fracture, 7 showed postoperative weakness or dysaesthesia, 3 of which had not resolved by 2 years. Eight patients underwent unplanned further surgery, 3 for pseudarthrosis.

CONCLUSIONS

RIF and IFIS show similar radiologic outcomes. RIF shows a higher rate of unplanned return to surgery, pseudarthrosis and persisting neurological changes.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.