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.

The Joe-Lin Operative Classification System for Pediatric Lumbosacral Spondylolysis and Spondylolisthesis.

OBJECTIVE: To propose and validate a novel and comprehensive classification of lumbosacral spondylolysis and spondylolisthesis in the pediatric population according to surgical managements. METHODS: Cases of pediatric lumbosacral (L5/S1 level) spondylolysis and spondylolisthesis were reviewed. Lumbar Japanese Orthopedics Association score, health-related quality of life, spondylolisthesis, lumbosacral disc degeneration, and dysplastic features were included for evaluation of outcomes after surgery. We also conducted a reliability study to assess the classification. RESULTS: A classification containing 4 types and a tentative treatment algorithm were proposed: type 1, direct pars repair without segmented fusion, for which the pedicle screw-U rod system is suitable; type 2, simple L5-S1 fusion; type 3, simple L4-S1 fusion; and type 4, simple L5-S2 fusion. All types of spondylolisthesis were suggested to achieve complete reduction and decompression. A total of 162 patients were included and we also reviewed the outcomes of patients in each type. All patients achieved satisfied outcomes. The reliability study showed that the average interobserver agreement was 89.5% (range, 85.2%-92.6%), with κ value of 0.862 (range, 0.802-0.901). Intraobserver agreement ranged from 88.9% to 92.6%, with an average κ value of 0.868 (range, 0.835-0.901). CONCLUSIONS: In our study, we proposed and validated a novel comprehensive classification of pediatric lumbosacral spondylolysis and spondylolisthesis. The pedicle screw-U rod system provided more benefits in the treatment of simple lumbosacral spondylolysis, and fusion from L5 to S2 combined with S2 screw would also benefit patients with high-degree spondylolisthesis.

Lumbar Vertebral Endplate Defects on Magnetic Resonance Imaging in Degenerative Spondylolisthesis: Novel Classification, Characteristics, and Correlative Factor Analysis.

BACKGROUND: Endplate defects are commonly seen in patients with lumbar degenerative disease. However, little is known about the presence of endplate defects in patients with degenerative spondylolisthesis (DS). In the present study, we have introduced a classification system for endplate defects in patients with DS using routine magnetic resonance imaging findings and explored the correlative factors. METHODS: Endplate defects were classified into 3 major categories (rim defects, focal defects, and erosive defects) and 5 subtypes (anterior type, posterior type, arc type at the anterior rim, notch type, and Schmorl's nodes). The incidence rates of the endplate defects were compared between the slippage and nonslippage levels. The correlations between the endplate defects and age, sex, disc degeneration, Modic changes (MCs), body mass index, slippage segment, and slippage degree were analyzed. RESULTS: Endplate defects were present in 47.43% of the endplates in DS. The most common endplate defects were rim defects. The occurrence of endplate defects, especially anterior defects, was more common at the slippage levels. Endplate defects were associated with age and closely related to MCs and the severity of disc degeneration. The slippage degree, slippage segment, body mass index, and sex differences were not associated with endplate defects in our study. The results obtained using this novel classification system were stable and consistent. CONCLUSIONS: The results from the present study have shown that the novel radiological classification system of endplate defects is reliable. Endplate defects were associated with slippage but not with the slippage degree or slippage segment differences in DS. The correlation between endplate defects and age and between MCs and disc degeneration were important features on the magnetic resonance imaging scans of patients with DS.

A ball-slide-type interbody distractor is effective in posterior reduction and internal fixation for patients with mid- to high-grade isthmic spondylolisthesis enrolled in a randomized clinical trial.

STUDY DESIGN: Clinical and radiographic results of a randomized, controlled, double-blind clinical trial OBJECTIVE:: To investigate the clinical applicability of a ball-point slide-type interbody distractor in posterior reduction and internal fixation for mid- to high-grade isthmic spondylolisthesis. SUMMARY OF BACKGROUND DATA: Posterior reduction and internal fixation is the effective treatment for spondylolisthesis. However, for the mid and high-grade isthmic spondylolisthesis patients with the conditions of vertebral osteoporosis and extremely narrow intervertebral space, the reduction is difficult; post-surgery intervertebral space height lost becomes serious; the fracture and loosening rate of fixation system is higher. No study regarding the prevention of these adverse outcomes in this technique is reported. METHODS: A total of 59 patients of mid and high-grade isthmic spondylolisthesis were randomly divided into random groups (investigational group and control group) applying simple randomized method in this study. In addition, 30 patients received posterior reduction and internal fixation as control. Twenty-nine patients received posterior reduction and internal fixation by ball-point slide-type interbody distractor were assigned to the investigational group. X-ray examination was performed before and after operation. The degree of reduction, height of intervertebral space were compared. The preoperative and postoperative Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were evaluated. Additionally, rate of the fixation system fracture was also assessed. RESULTS: Before treatment, there were no significant differences in ISH (P = .72), DR (P = .85), VAS of back pain (P = .55), VAS of leg pain (P = .83) and ODI (P = .68) were found between 2 groups. After 12-month treatment, there were no significant differences in ISH (P = .26), VAS of back pain (P = .09) and VAS of leg pain (P = .96) between two groups. Significant differences of DR (P = .02), ODI (P = .03) and adverse events (P = .00) were found between 2 groups. CONCLUSIONS: The results of this prospectively study showed that the ball-point slide-type interbody distractor in the posterior reduction and internal fixation produced good outcomes after 12-month treatment. More high quality randomized controlled trials and cases should still be needed to warrant the results of this study.

Comparative Sacral Morphology in Spondylolisthesis Patients.

STUDY DESIGN: Retrospective comparative case series. OBJECTIVES: Evaluation of sacral morphology in spondylolisthesis patients compared with asymptomatic controls. SUMMARY OF BACKGROUND DATA: Patients with spondylolisthesis are known to differ from asymptomatic controls in sagittal plane anatomy, but few studies examine the coronal and axial plane differences in these cohorts. METHODS: This is a retrospective evaluation of magnetic resonance imaging of the lumbosacral spine in 29 spondylolisthesis patients and an asymptomatic cohort (n = 154). Measurements of the linear distance and angular position of L5 and sacrum were performed in the sagittal, coronal, and axial planes. Receiver operating characteristic (ROC) curve analysis quantified these associations. High- and low-grade spondylolisthesis patients were compared with two-sample t-tests. All p-values are two-sided and considered significant when p < .05. RESULTS: Axial measurements showed the distance of the right to left anterior ala and the L5 body width did not differ between the cohorts. Sacroiliac (SI) joint angles in the spondylolisthesis cohort were closer to the true sagittal plane than in the controls 109° versus 121° (p < .001). In the sagittal plane, the linear measurement of the ratio of the midpoint anteroposterior width L5 to the sacral end plate was larger in the high-grade patients than the low-grade patients and controls. In addition, the kyphosis between S1-S2 and S2-S3 was larger in the spondylolisthesis cohort. CONCLUSIONS: The SI joints in patients with spondylolisthesis were orientated closer to the sagittal plane than in the controls. An awareness of this positioning may be important in surgical implant insertion as well as rehabilitation of hip extensor weakness. The main anatomical differences found in this study were in the sagittal plane. Sacral end plate abnormalities were well visualized and consistent with radiographic findings in the literature. LEVEL OF EVIDENCE: Level III, diagnostic.

[Surgical Treatment of High-Grade High-Dysplastic Spondylolistheses in Young Patients - Prospective Monocentric Study of 29 Patients]. / Operacní lécba vysokostupnových vysoce dysplastických spondylolistéz u mladých jedincu ­ prospektivní monocentrická studie 29 pacientu.

PURPOSE OF THE STUDY An optimal technique to surgically treat high-grade high-dysplastic (HG HD)spondylolistheses remains disputable. There are multiple surgical procedures described, ranging from a simple posterior fusion in situ without fixation through a standalone anterior lumbar interbody fusion with the oblique insertion of a structural bonegraft to instrumented full reduction and 360-degree fusion. At our department, preference is given to the instrumented monosegmental reduction and fixation by a fixator with Schanz screws. The aim of this paper is a prospective clinical and radiological evaluation of the group of operated patients below 30 years of age with HG HD spondylolisthesis with a slip greater than 50%. MATERIAL AND METHODS In the period from 11/2007 to 2/2017, a total of 29 patients with HG HD spondylolisthesis always of the L5-S1 segment were treated at the Department of Spinal Surgery of the First Faculty of Medicine of the Charles University and the Teaching Hospital Motol. They were 10 men and 19 women aged 10 to 28 years, with the mean age of 18.4 years. In 27 patients reduction and single-segment fixation of L5-S1 were performed as primary treatment, in one case decompression and noninstrumented-fusion only was carried out and in one case in situ fixation of L4-L5-S1 for distinctive osteoporosis. RESULTS The average duration of posterior surgery without the reconstruction of the anterior column was 88.9 min, in case of anterior fusion it was 46.6 min and in case of only posterior approach and fusion with the reconstruction of the anterior column it was 141.5 min. The average blood loss in the posterior fusion without the reconstruction of the anterior column reached 384.3 ml, in the stand-alone anterior fusion it was 21.6 ml. and in the posterior fusion with the reconstruction of the anterior column 430.0 ml. In 27 patients in whom the reduction was carried out, a shift of the L5 vertebral body observed on the CT scan prior to the surgery was 64.3% on average, while postoperatively and also at 6 months after the surgery during the follow-up examination it was 8.1%. A clear bone posterolateral fusion was found by the CT examination after 4-6 months in all 29 patients (100%, N = 29), while bone intersomatic fusion was reported in 25 cases (96.2%, N = 26). Altogether 6.9% of residual neurological deficits were observed. The statistical processing of VAS values for lumbar back pain and ODI values before the surgery and after two years confirmed a significant improvement of the clinical condition (p < 0.001). When asked whether they would undergo the same surgery with their current experience with the treatment, all the 29 patients answered "yes" and stressed the functional as well as the aesthetic results of the surgery. DISCUSSION In agreement with the other authors, the PT, SS and PI values are measured and we consider the SA, SDSG LSA and Dubousset s LSA assessments to be essential. All the measured values showed statistically significant changes postoperatively, only the pelvic incidence(PI) value remained unchanged. In patients with HG HD spondylolisthesis, we prefer reduction and the 360-degree monosegmental fusion, in the case of sacral osteotomy always using the posterior approach, in the cases where osteotomy is not performed using the next anterior approach. Even in the cases of the most severe deformities, we prefer to maintain the body of L5 and, where necessary, rather shorten the sacrum, which in our opinion leads to a better aesthetic result. CONCLUSIONS The reduction by single-segment instrumentation is a suitable alternative to the surgical therapy of HG HD spondylolistheses in young patients. It provides a high success rate of bone fusion and good clinical results including the aesthetic aspects. The complications associated with full reduction are not markedly higher than in other surgical techniques. Key words:spondylolisthesis, HGHD, high-grade, high-dysplastic, reduction, pelvic incidence, pelvic tilt, sacral slope.

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.

Higher Improvement in Patient-Reported Outcomes Can Be Achieved After Transforaminal Lumbar Interbody Fusion for Clinical and Radiographic Degenerative Spondylolisthesis Classification Type D Degenerative Lumbar Spondylolisthesis.

BACKGROUND: Clinical and radiographic degenerative spondylolisthesis (CARDS) classification defines a distinct subset of patients with kyphotic angulation at the involved segment (type D). Research using CARDS classification to investigate motion characteristics at involved segments or patient-related outcomes (PROs) following surgical intervention is sparse. We investigated the relationship between CARDS type D spondylolisthesis and dynamic instability and PROs in type D versus non-type D spondylolisthesis. METHODS: We reviewed consecutive patients who received transforaminal lumbar interbody fusion for L4-5 spondylolisthesis between 2009 and 2015. Patients were assigned into type D and non-type D groups. Translational motion was determined by upright lumbar lateral radiography with supine sagittal magnetic resonance imaging or flexion and extension radiography. Demographics, radiographic parameters, and PROs were evaluated. RESULTS: Type D and non-type D groups comprised 34 and 163 patients, respectively. Compared with non-type D, type D group was characterized by lordotic angulation loss and higher degree of olisthesis on upright radiographs and demonstrated higher translational motion on upright lumbar lateral radiography with supine sagittal magnetic resonance imaging analysis. After surgery, mean reduction rate was significantly higher in type D group; type D had less slippage, but differences in slip angle and disc height were not significant. Preoperative Oswestry Disability Index and visual analog scale for back pain scores were higher in type D group. Type D spondylolisthesis and dynamic instability were associated with achieving minimal clinically important differences in PROs. CONCLUSIONS: CARDS type D spondylolisthesis is a distinct subset associated with dynamic instability and worse PROs. Higher improvement in PROs can be achieved in CARDS type D spondylolisthesis after surgery.

Current Evidence Regarding the Diagnostic Methods for Pediatric Lumbar Spondylolisthesis: A Report From the Scoliosis Research Society Evidence Based Medicine Committee.

STUDY DESIGN: Structured literature review. OBJECTIVES: The Scoliosis Research Society (SRS) requested an assessment of the current state of peer-reviewed evidence regarding pediatric lumbar spondylolisthesis with the goal of identifying what is known and what gaps remain in further understanding the diagnostic methods for pediatric spondylolisthesis. SUMMARY OF BACKGROUND DATA: Spondylolisthesis in the lumbar spine is common among children and adolescents and no formal synthesis of the published literature regarding diagnostic methods has been previously performed. METHODS: A comprehensive literature search was performed. Abstracts were reviewed and data from included studies were analyzed by the committee. From 6600 initial citations with abstract, 663 articles underwent full-text review. The best available evidence for the clinical questions regarding diagnostic methods was provided by 26 included studies. Six of the studies were graded as Level III (retrospective comparative), and represent the current best available evidence whereas 20 of the studies were graded as Level IV (retrospective case series) evidence. No Level V (expert opinion) studies were included in the final list. None of the studies were graded as Level I or Level II. RESULTS: Plain radiography is the workhorse imaging modality for diagnosing spondylolisthesis. No association between radiologic grade of spondylolisthesis and clinical presentation were noted; however, grade III and IV slips more often required surgery, and increasing slip angles were associated with worse baseline outcome scores. There is Level III evidence that the Meyerding grade appears to be more accurate for measuring slip percentage whereas the Lonstein Slip angle and Dubousset Lumbosacral Kyphosis angles are the best for measuring lumbosacral kyphosis in spondylolisthesis. In addition, higher sacral table index, pelvic incidence, sacral slope, and lower sacral table angle were associated with spondylolisthesis. True incidence could not be determined by the current literature available. However, studies in adolescent athletes demonstrated an incidence of 6% to 7% across studies. CONCLUSIONS: The current "best available" evidence to guide the diagnosis and characterization of pediatric spondylolisthesis is presented. Future studies are needed to provide more high-quality evidence to answer these clinically relevant questions. LEVEL OF EVIDENCE: Level III, review of Level III studies.

Reliability and Clinical Utility of the CARDS Classification for Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of this study is to determine the reliability and clinical utility of the of the proposed CARDS classification for degenerative spondylolisthesis. BACKGROUND: The Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) classification system was recently proposed as an alternative to the Meyerding system for classifying degenerative spondylolisthesis (DS). Unlike Meyerding, CARDS considers other relevant radiographic findings such as disk space collapse and segmental kyphosis to stratify DS into 4 radiographically discreet types. Currently, no studies have been conducted to assess the clinical utility of the CARDS system. METHODS: A total of 78 consecutive surgical patients with L4-L5 DS were rated as CARDS types A through D and Fleiss' κ for interobserver agreement was calculated. Then, demographics as well as preoperative and postoperative outcome scores (ODI, SF-12 mental and physical, VAS) were collected. The Kruskal-Wallis test was used to detect significant differences amongst CARDS types. An unpaired t test was used to compare individual CARDS types with all other subtypes combined. RESULTS: Grading showed: 4 type A, 19 type B, 45 type C, and 8 type D (k=0.63). There was a statistically significant difference in preoperative back pain (P=0.046) between groups. CARDS type D had the highest mean back pain scores (8.8) of all subtypes which was significantly higher than mean back pain for all other subtypes combined (P=0.016). CARDS D showed the largest degree of improvement in all outcome measures. There was a trend towards an increased improvement in ODI (P=0.074) and SF-12 MCS (P=0.095) in the CARDS D subtype relative to the rest of the cohort. CONCLUSIONS: The CARDS classification system represents a reliable method for classifying cases of DS. Our results indicate that kyphotic segmental alignment (CARDS D) may be a less common, yet clinically distinct subset of DS characterized by worse preoperative back pain. CARDS type D cases may also show a greater degree of improvement in multiple outcome measures following surgical intervention.

A new classification system for degenerative spondylolisthesis of the lumbar spine.

PURPOSE: There is no consensus for a comprehensive analysis of degenerative spondylolisthesis of the lumbar spine (DSLS). A new classification system for DSLS based on sagittal alignment was proposed. Its clinical relevance was explored. METHODS: Health-related quality-of-life scales (HRQOLs) and clinical parameters were collected: SF-12, ODI, and low back and leg pain visual analog scales (BP-VAS, LP-VAS). Radiographic analysis included Meyerding grading and sagittal parameters: segmental lordosis (SL), L1-S1 lumbar lordosis (LL), T1-T12 thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), and sagittal vertical axis (SVA). Patients were classified according to three main types-1A: preserved LL and SL; 1B: preserved LL and reduced SL (≤5°); 2A: PI-LL ≥10° without pelvic compensation (PT < 25°); 2B: PI-LL ≥10° with pelvic compensation (PT ≥ 25°); type 3: global sagittal malalignment (SVA ≥40 mm). RESULTS: 166 patients (119 F: 47 M) suffering from DSLS were included. Mean age was 67.1 ± 11 years. DSLS demographics were, respectively: type 1A: 73 patients, type 1B: 3, type 2A: 8, type 2B: 22, and type 3: 60. Meyerding grading was: grade 1 (n = 124); grade 2 (n = 24). Affected levels were: L4-L5 (n = 121), L3-L4 (n = 34), L2-L3 (n = 6), and L5-S1 (n = 5). Mean sagittal parameter values were: PI: 59.3° ± 11.9°; PT: 24.3° ± 7.6°; SVA: 29.1 ± 42.2 mm; SL: 18.2° ± 8.1°. DSLS types were correlated with age, ODI and SF-12 PCS (ρ = 0.34, p < 0.05; ρ = 0.33, p < 0.05; ρ = -0.20, and p = 0.01, respectively). CONCLUSION: This classification was consistent with age and HRQOLs and could be a preoperative assessment tool. Its therapeutic impact has yet to be validated. LEVEL OF EVIDENCE: 4.

Clinical classification in low back pain: best-evidence diagnostic rules based on systematic reviews.

BACKGROUND: Clinical examination findings are used in primary care to give an initial diagnosis to patients with low back pain and related leg symptoms. The purpose of this study was to develop best evidence Clinical Diagnostic Rules (CDR] for the identification of the most common patho-anatomical disorders in the lumbar spine; i.e. intervertebral discs, sacroiliac joints, facet joints, bone, muscles, nerve roots, muscles, peripheral nerve tissue, and central nervous system sensitization. METHODS: A sensitive electronic search strategy using MEDLINE, EMBASE and CINAHL databases was combined with hand searching and citation tracking to identify eligible studies. Criteria for inclusion were: persons with low back pain with or without related leg symptoms, history or physical examination findings suitable for use in primary care, comparison with acceptable reference standards, and statistical reporting permitting calculation of diagnostic value. Quality assessments were made independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies tool. Clinical examination findings that were investigated by at least two studies were included and results that met our predefined threshold of positive likelihood ratio ≥ 2 or negative likelihood ratio ≤ 0.5 were considered for the CDR. RESULTS: Sixty-four studies satisfied our eligible criteria. We were able to construct promising CDRs for symptomatic intervertebral disc, sacroiliac joint, spondylolisthesis, disc herniation with nerve root involvement, and spinal stenosis. Single clinical test appear not to be as useful as clusters of tests that are more closely in line with clinical decision making. CONCLUSIONS: This is the first comprehensive systematic review of diagnostic accuracy studies that evaluate clinical examination findings for their ability to identify the most common patho-anatomical disorders in the lumbar spine. In some diagnostic categories we have sufficient evidence to recommend a CDR. In others, we have only preliminary evidence that needs testing in future studies. Most findings were tested in secondary or tertiary care. Thus, the accuracy of the findings in a primary care setting has yet to be confirmed.

The effect of transforaminal epidural steroid injections in patients with spondylolisthesis.

BACKGROUND: Transforaminal epidural steroid injection (TFE) is a widely accepted non-surgical treatment for pain in patients with spondylolisthesis. However, the effectiveness of TFE has not been compared in patients with degenerative (DS) and isthmic spondylolisthesis (IS). OBJECTIVE: To compare the effectiveness of bilateral TFEs in DS and IS. METHODS: Patients who underwent bilateral TFEs for spondylolisthesis at University of California San Francisco Orthopaedic Institute from 2009 to 2014 were evaluated retrospectively. RESULTS: DS patients (120 female, 51 male) were significantly older and had higher comorbidity than those with IS (18 female, 14 male). They had better pain relief after TFE than patients with IS (72.11 ± 27.46% vs 54.39 ± 34.31%; p = 0.009). The number of TFEs, the mean duration of pain relief after TFE, follow-up periods, translation and facet joint widening were similar in DS and IS groups (p > 0.05). DS group had higher successful treatment rate (66.1% vs 46.9%, p = 0.009) and longer duration of pain relief (181.29 ± 241.37 vs 140.07 ± 183.62 days, p = 0.065) compared to IS group. CONCLUSIONS: Bilateral TFEs at the level of spondylolisthesis effectively decreased pain in patients. TFEs provided better pain relief for longer duration in patients with DS than for those with IS.

[Analysis of clinical outcomes of simplified treatment of lumbar spondylolisthesis with adjacent segment degeneration by MAST Quadrant].

OBJECTIVE: To explore the method and clinical effect of MAST Quadrant for lumbar spondylolisthesis with adjacent segment degeneration. METHODS: From April 2014 to January 2016, 36 cases of lumbar spondylolisthesis with adjacent segment degeneration were treated by MAST Quadrant(target nerve decompression and transforaminal lumbar interbody fusion or articulationes zygapophysiales fusion by unilateral fixation with MAST Quadrant). Twenty-three cases were degenerative lumbar spondylolisthesis and 13 cases were isthmic lumbar spondylolisthesis. According to Meyerding grade of spondylolisthesis, 16 cases were grade I, 17 cases were grade II, and 3 cases were grade III. Visual analogue score (VAS), Oswesty Disability Index (ODI) and JOA score were used to evaluate the clinical outcome. RESULTS: The amount of intraoperative bleeding was 230 to 480 ml with an average of 340 ml and the amount of postoperative blood loss was 15 to 80 ml with an average of 43 ml. Operative time was 176 to 240 min with an average of 193 min; X-ray exposure time was 2 to 6 s with an average of 3.6 s. Two cases were complicated with dural tear without nerve injury during operation. Thirty cases were followed up from 12 to 17 months with an average of 15.2 months. VAS scores for preoperative, 5 days, 3 months after surgery were 7.6±1.7, 1.9±0.4, 0.8±0.4 respectively, and there was significant difference before and after operation(P<0.05). The ODI scores for preoperative and 3 months after surgery were 35.9±1.2 and 3.7±0.7 respectively, and there was significant difference before and after operation(P<0.05). JOA scores for preoperative, 5 days, 1 months, 3 months after surgery were 13.2±0.4, 24.4±0.4, 27.4±0.1, 27.9±0.5 respectively, and there was significant difference before and after operation(P<0.05). CONCLUSIONS: MAST Quadrant can be applied to treat lumbar spondylolisthesis with adjacent segment degeneration, and the minimally invasive sugical technique is a safe and effective method, with the advantage of simple operation, fast recovery.

Return of motor evoked potentials after knee flexion in the setting of high-grade spondylolisthesis.

PURPOSE: To present a case of loss of motor-evoked potentials (MEPs) to the left foot in the supine position after a partial reduction and instrumented fusion from L4 to pelvis which was managed successfully without revision or removal of implants. METHODS: We report a patient with high-grade spondylolisthesis who demonstrated loss of motor-evoked potentials after posterior spinal fusion and transfer to supine position. The patient's knees were flexed to 90° and signals were immediately restored. Systemic steroids were administered and circumferential fusion was delayed 21 days. Anterior-interbody cage was placed without complication. RESULTS: She was discharged on post-operative day 2. At 7 months, she is pain free and doing well with plans to return to gymnastics completely. CONCLUSIONS: Knee flexion can be instituted when encountering a neuromonitoring signal change following posterior spinal fusion for spondylolisthesis as a means to alleviate acute nerve stretch injury and may in some cases prevent the need to lessen the correction. LEVEL OF EVIDENCE: IV.

Validation and Reliability Analysis of the Spinal Deformity Study Group Classification for L5-S1 Lumbar Spondylolisthesis.

STUDY DESIGN: An intra- and interobserver reliability study. OBJECTIVE: To assess the intra- and interobserver reliability of the Spinal Deformity Study Group (SDSG) system for classifying adolescent and adult L5-S1 spondylolisthesis. SUMMARY OF BACKGROUND DATA: Reliability of the SDSG classification has only been previously validated in adolescent patients as performed by the SDSG study group investigators. METHODS: A total of 80 patients with L5-S1 spondylolisthesis were included in this study. Only dysplastic and isthmic spondylolisthesis were included in this study. Long-cassette standing lateral radiographs of the spine and pelvis were obtained. All 80 cases were classified according to the SDSG classification by four observers. After a 2-week interval, the same classification was independently repeated by each observer with the cases in a different randomly assigned order. The Fleiss' κ coefficient was calculated to test the intra- and interobserver reliabilities of the SDSG classification. RESULTS: The present study included all six types of SDSG classification. Overall intra- and interobserver agreements were 86.6% (κ: 0.830) and 73.3% (κ: 0.648), respectively. The intra- and interobserver agreements and repeatability associated with slip grade were 89.7% (κ: 0.824) and 87.7% (κ: 0.721), respectively. Regarding sacropelvic and spinal balance, intra- and interobserver agreements and repeatability were 83.7% (κ: 0.735) and 77.5% (κ: 0.602) for low-grade slips, and 90.75% (κ: 0.883) and 90.4% (κ: 0.851) for high-grade slips, respectively. CONCLUSION: Substantial intra- and interobserver reliability was found for the SDSG classification in L5-S1 lumbar spondylolisthesis. SDSG classification system is a simple and clear classification scheme incorporating spinopelvic parameters, which provides significant clinical utility. LEVEL OF EVIDENCE: 3.

Posterolateral fusion with interbody for lumbar spondylolisthesis is associated with less repeat surgery than posterolateral fusion alone.

OBJECTIVE: Posterior or transforaminal lumbar interbody fusions (PLIF/TLIF) may improve the outcomes in patients with lumbar spondylolisthesis. This study aims to compare outcomes after posterolateral fusion (PLF) only versus PLF with interbody fusion (PLF+PLIF/TLIF) in patients with spondylolisthesis. METHODS: We retrospectively reviewed103 patients who underwent first-time instrumented lumbar fusions for degenerative or isthmic spondylolisthesis. Anterior techniques and multilevel interbody fusions were excluded. All patients were followed for at least 2 years postoperatively. Clinical outcomes including back pain, radiculopathy, weakness, sensory deficits, and loss of bowel/bladder function were ascertained from clinic notes. Radiographic measures were calculated with Tillard percentage of spondylolisthesis. Reoperation for progression of degenerative disease, a primary endpoint, was indicated for all patients with (1) persistent or new-onset neurological symptoms; and (2) radiographic imaging that correlated with clinical presentation. RESULTS: Of the 103 patients, 56.31% were managed with PLF and 43.69% with PLF+PLIF/TLIF. On radiographic studies, spondylolisthesis improved by a mean of 13.06% after PLF+PLIF/TLIF versus 5.67% after PLF (p<0.001). In comparison to PLF+PLIF/TLIF, patients undergoing PLF experienced higher rates of postoperative improvement in back pain, sensory deficits, motor weakness, radiculopathy, and bowel/bladder difficulty; however, these differences did not reach statistical significance. The PLF cohort had a significantly higher incidence of reoperation (p=0.011) and pseudoarthrosis/instrumentation failure (p=0.043). In the logistical analyses, non-interbody fusion was the strongest predictor of reoperation for progression of degenerative disease. CONCLUSION: Compared to PLF only, PLF+PLIF/TLIF were statistically significantly associated with a greater correction of spondylolisthesis. Patients with interbody fusions were less likely to undergo reoperation for degenerative disease progression compared to non-interbody fusions. However, greater listhesis correction and decreased reoperation in the PLF+PLIF/TLIF cohort should be weighed with favorable clinical outcomes in the PLF cohort.