Opportunistic prediction of osteoporosis in patients with degenerative lumbar diseases: a simplified T12 vertebral bone quality approach.

BACKGROUND: Osteoporosis is one of the risk factors for screw loosening after lumbar fusion. However, the probability of preoperative osteoporosis screening in patients with lumbar degenerative disease is low. Therefore, the aim of this study was to investigate whether a simplified vertebral bone quality (VBQ) score based on T12 T1-MRI could opportunistically predict osteoporosis in patients with degenerative lumbar spine diseases. METHODS: We retrospectively analyzed cases treated for lumbar degenerative diseases at a single institution between August 2021 and June 2022. The patients were divided into three groups by the lowest T-score: osteoporosis group, osteopenia group, and normal bone mineral density (BMD) group. The signal intensity based on the T12 vertebral body divided by the signal intensity of the cerebrospinal fluid was calculated to obtain the simplified VBQ score, as well as the CT-based T12HU value and the traditional L1-4VBQ score. Various statistical analyses were used to compare VBQ, HU and DEXA, and the optimal T12VBQ threshold for predicting osteoporosis was obtained by plotting the receiver operating curve (ROC) analysis. RESULTS: Total of 166 patients were included in this study. There was a statistically significant difference in T12VBQ scores between the three groups (p < 0.001). Pearson correlation showed that there was a moderate correlation between T12VBQ and T-score (r=-0.406, p < 0.001). The AUC value of T12VBQ, which distinguishes between normal and low BMD, was 0.756, and the optimal diagnostic threshold was 2.94. The AUC value of T12VBQ, which distinguishes osteoporosis from non-osteoporosis, was 0.634, and the optimal diagnostic threshold was 3.18. CONCLUSION: T12VBQ can be used as an effective opportunistic screening method for osteoporosis in patients with lumbar degenerative diseases. It can be used as a supplement to the evaluation of DEXA and preoperative evaluation. TRIAL REGISTRATION: retrospectively registered number:1502-009-644; retrospectively registered number date:27 oct 2022.

Evaluating lumbar disc degeneration by MRI quantitative metabolic indicators: the perspective of factor analysis.

PURPOSE: This study aimed to investigate an early diagnostic method for lumbar disc degeneration (LDD) and improve its diagnostic accuracy. METHODS: Quantitative biomarkers of the lumbar body (LB) and lumbar discs (LDs) were obtained using nuclear magnetic resonance (NMR) detection technology. The diagnostic weights of each biological metabolism indicator were screened using the factor analysis method. RESULTS: Through factor analysis, common factors such as the LB fat fraction, fat content, and T2* value of LDs were identified as covariates for the diagnostic model for the evaluation of LDD. This model can optimize the accuracy and reliability of LDD diagnosis. CONCLUSION: The application of biomarker quantification methods based on NMR detection technology combined with factor analysis provides an effective means for the early diagnosis of LDD, thereby improving diagnostic accuracy and reliability.

Long-term efficacy of Waveflex semi-rigid-dynamic-internal-fixation system in delaying intervertebral disc degeneration at adjacent segments and improving spinal sagittal imbalance.

The Waveflex semi-rigid-dynamic-internal-fixation system shows good short-term effects in the treatment of lumbar degenerative diseases, but there are few long-term follow-up studies, especially for recovery of sagittal balance. Fifty patients with lumbar degenerative diseases treated from January 2016 to October 2017 were retrospectively analysed: 25 patients treated with Waveflex semi-rigid-dynamic-internal-fixation system (Waveflex group) and 25 patients treated with double-segment PLIF (PLIF group). Clinical efficacy was evaluated by Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). Imaging data before surgery and at 3 months, 1 year, and 5 years postoperatively was used for imaging indicator assessment. Local disc degeneration of the cephalic adjacent segment (including disc height index (DHI), intervertebral foramen height (IFH), and range of motion (ROM)) and overall spinal motor function (including lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), and |PI-LL|) were analysed. Regarding clinical efficacy, comparison of VAS and ODI scores between the Waveflex and PLIF groups showed no significant preoperative or postoperative differences. The comparison of the objective imaging indicators showed no significant differences in the DHI, IFH, LL, |PI-LL|, and SS values between the Waveflex and PLIF groups preoperatively and 3 months postoperatively (P > 0.05). These values were significantly different at 1 and 5 years postoperatively (P < 0.05), and the Waveflex group showed better ROM values than those of the PLIF group (P < 0.05). PI values were not significantly different between the groups, but PT showed a significant improvement in the Waveflex group 5 years postoperatively (P < 0.05). The Waveflex semi-rigid dynamic fixation system can effectively reduce the probability of intervertebral disc degeneration in upper adjacent segments. Simultaneously, patients in the Waveflex group showed postoperative improvements in LL, spinal sagittal imbalance, and quality of life.

Risk factors for early-onset adjacent segment degeneration after one-segment posterior lumbar interbody fusion.

Adjacent segment degeneration (ASD) is a major postoperative complication associated with posterior lumbar interbody fusion (PLIF). Early-onset ASD may differ pathologically from late-onset ASD. The aim of this study was to identify risk factors for early-onset ASD at the cranial segment occurring within 2 years after surgery. A retrospective study was performed for 170 patients with L4 degenerative spondylolisthesis who underwent one-segment PLIF. Of these patients, 20.6% had early-onset ASD at L3-4. In multivariate logistic regression analysis, preoperative larger % slip, vertebral bone marrow edema at the cranial segment on preoperative MRI (odds ratio 16.8), and surgical disc space distraction (cut-off 4.0 mm) were significant independent risk factors for early-onset ASD. Patients with preoperative imaging findings of bone marrow edema at the cranial segment had a 57.1% rate of early-onset ASD. A vacuum phenomenon and/or concomitant decompression at the cranial segment, the degree of surgical reduction of slippage, and lumbosacral spinal alignment were not risk factors for early-onset ASD. The need for fusion surgery requires careful consideration if vertebral bone marrow edema at the cranial segment adjacent to the fusion segment is detected on preoperative MRI, due to the negative impact of this edema on the incidence of early-onset ASD.

Efficacy of PE-PLIF with a novel ULBD approach for lumbar degeneration diseases: a large-channel endoscopic retrospective study.

PURPOSE: This study aims to assess the effectiveness of Percutaneous Endoscopic Posterior Lumbar Interbody Fusion (PE-PLIF) combined with a novel Unilateral Laminotomy for Bilateral Decompression (ULBD) approach using a large-channel endoscope in treating Lumbar Degenerative Diseases (LDD). METHODS: This retrospective analysis evaluates 41 LDD patients treated with PE-PLIF and ULBD from January 2021 to June 2023. A novel ULBD approach, called 'Non-touch Over-Top' technique, was utilized in this study. We compared preoperative and postoperative metrics such as demographic data, Visual Analogue Scale (VAS) for pain, Oswestry Disability Index (ODI), Japanese Orthopedic Association (JOA) score, surgical details, and radiographic changes. RESULTS: The average follow-up duration was 14.41 ± 2.86 months. Notable improvements were observed postoperatively in VAS scores for back and leg pain (from 5.56 ± 0.20 and 6.95 ± 0.24 to 0.20 ± 0.06 and 0.12 ± 0.05), ODI (from 58.68 ± 0.80% to 8.10 ± 0.49%), and JOA scores (from 9.37 ± 0.37 to 25.07 ± 0.38). Radiographic measurements showed significant improvements in lumbar and segmental lordosis angles, disc height, and spinal canal area. A high fusion rate (97.56% at 6 months, 100% at 12 months) and a low cage subsidence rate (2.44%) were noted. CONCLUSIONS: PE-PLIF combined with the novel ULBD technique via a large-channel endoscope offers significant short-term benefits for LDD management. The procedure effectively expands spinal canal volume, decompresses nerve structures, improves lumbar alignment, and stabilizes the spine. Notably, it improves patients' quality of life and minimizes complications, highlighting its potential as a promising LDD treatment option.

Novel Risk Factors for Cervical Facet Joint Degeneration in the Subaxial Cervical Spine: Correlation with Cervical Sagittal Alignment and Bone Mineral Density.

OBJECTIVE: The impact of cervical sagittal alignment on cervical facet joint degeneration (CFD) and the risk factors for CFD in patients with degenerative cervical myelopathy (DCM) were investigated in the current study. METHODS: A total of 250 surgical patients with DCM were recruited. The clinical data and radiographical characteristics, including CFD, cervical sagittal balance parameters, Hounsfield unit (HU) values, disc degeneration (DD), and modic change, were collected. The detailed correlation between these characteristics and CFD was analyzed. Characteristics, including CFD, were compared among the various cervical alignment types and different CFD groups. Finally, the risk factors for CFD were revealed via logistic regression. RESULTS: CFD was prevalent in DCM patients. Age, cervical sagittal vertical axis (cSVA), range of motion, T1 slope, thoracic inlet angle, DD, HU value, and modic change correlated with CFD segmentally and globally (P < 0.05). The lordosis and sigmoid types had a significantly higher CFD prevalence (P < 0.05). Furthermore, the average CFD threshold for the severe CFD group was 1.625 (area under the curve, 0.958). Additionally, 167 patients with average CFD <1.625 and 83 patients with CFD of ≥1.625 were classified into the mild CFD group and severe CFD group, respectively. Finally, multivariate analysis was performed, and age, cSVA, HU value, modic change, and DD were determined to be independent risk factors for CFD. CONCLUSIONS: The load distribution tends to shift to a more shear-like pattern in the sigmoid and kyphosis types and in those with a higher cSVA, thereby promoting CFD. Aging, cervical malalignment, low bone mineral density, DD, and modic change were revealed to result in high risks of CFD.

The Impact of the Placement of the L5 Vertebra in Relation to the Intercrest Line on the Level of Disc Herniation.

AIM: To determine whether there is a correlation between a deeply seated L5 vertebra in relation to the intercrest line (ICL) and the level of degeneration of lumbar discs. MATERIAL AND METHODS: The study included 152 patients who underwent surgery for lumbar disc herniation. After analyzing the radiographs, the patients were separated into two groups. Group 1 patients had an ICL that passed through the L4 corpus, and Group 2 patients had an ICL that passed through the L4-5 disc distance or the L5 vertebra. Group 1 patients were classified as having a deeply seated L5 vertebra, while Group 2 patients were classified as not having a deeply seated L5 vertebra. RESULTS: The study found that male patients had a significantly higher incidence of a deeply seated L5 vertebra compared to female patients (p=0.003). Patients who underwent surgery at the L4?5 level exhibited disc heights that were notably higher than those who underwent surgery at the L5-S1 level. In Group 1, 68% of the patients had surgery at the L4-5 level, compared to only 41.7% in Group 2 (p=0.009). CONCLUSION: When investigating the effects of the position of the L5 vertebra in relation to the ICL at the L4-5 and L5-S1 disc levels, the study found that having a deeply seated L5 vertebra protected against L5-S1 disc herniation and that L4-5 disc herniation was more common in these patients. This is believed to be due to the L5?S1 segment being less mobile when the L5 vertebra is deeply seated.

Analysis of Factors Associated with Lumbar Degenerative Disease Complicated by Baastrup's Disease.

OBJECTIVE: To investigate the factors associated with the occurrence of Baastrup's disease (BA) in patients with lumbar degenerative diseases (LDDs). METHODS: A retrospective analysis was conducted on 168 patients with LDDs (including lumbar disc herniation, lumbar spinal stenosis, and lumbar spondylolisthesis) who were treated at our hospital from January 2020 to January 2023, comprising 95 males and 73 females, aged 48-84 years.Patients were divided into two groups based on the presence of Baastrup's disease: those with BA (Group A) and those without BA (Group B).Relevant patient factors were extracted, including age, gender, occupation, smoking history, alcohol consumption history, body mass index, bone density, presence of internal diseases (diabetes, hypertension), lumbar lordosis angle, endplate Modic changes, degree of intervertebral disc degeneration, and facet joint degeneration (Weishaupt grading).Statistical analysis was performed using, Statistical Package for the Social Sciences 26.0 software to compare the differences in these factors between the two groups, and statistically significant results were included in a multivariate logistic regression analysis. RESULTS: Univariate analysis indicated that there were no statistically significant differences between the two groups in terms of gender, smoking history, alcohol consumption history, bone density, presence of internal diseases (diabetes, hypertension), lumbar lordosis angle, and endplate Modic changes (P>0.05),whereas age, occupation, body mass index, degree of intervertebral disc degeneration, and degree of facet joint degeneration showed statistically significant differences (P < 0.05).Multivariate logistic regression analysis revealed that age, degree of intervertebral disc degeneration, and degree of facet joint degeneration were independent risk factors for the occurrence of BA in patients with LDDs (P < 0.05). CONCLUSIONS: BA is relatively common in patients with LDDs, and advanced age, severe intervertebral disc degeneration, and facet joint degeneration are its independent risk factors.

Obstetric-related lower back pain: the effect of number of pregnancy on development of chronic lower back pain, worsening of lumbar disc degeneration and alteration of lumbar sagittal balance.

OBJECTIVE: This study aims to determine whether the number of pregnancies contributes to the development of chronic lower back pain, worsening the lumbar disc degeneration and altering the normal lumbar sagittal balance. MATERIAL METHOD: There are 134 ladies participated in this study. They are divided into two groups based on their number of pregnancies (parity). All patients with chronic back pain were assessed using a visual analog scale for pain and the Oswestry Disability Index for their functional status assessment. Degenerative signs in lumbar MRI, which are Modic changes and the presence of Schmorl's node, were evaluated. Besides that, the sagittal balance of the lumbar spine was also measured via an erect lumbar plain radiograph. RESULTS: Patients with parities < 5 were included in Group 1, and those with parities ≥ 5 in Group 2. The mean visual analog scale score of Group 2 was significantly higher than that of Group 1 (8.42 ± 1.34 vs.6.50 ± 1.61). The mean Oswestry Disability Index score in Group 2 was significantly higher than that of Group 1 (29.87 ± 6.75 vs.18.41 ± 7.97). This relationship between the groups in terms of Modic change was statistically significant. The relationship between the groups regarding the presence of Schmorl's nodes was also statistically significant. The difference between the groups in terms of sagittal balance parameters was not statistically significant. CONCLUSION: Chronic lower back pain is significantly worse and associated with more disability in patients with more than five previous pregnancies. MRI degenerative changes are also significantly higher in these grand multipara groups.

Incidence and risk factors of distal adjacent disc degeneration in adolescent idiopathic scoliosis patients undergoing fusion surgery: a systematic review and meta-analysis.

PURPOSE: The objective of this meta-analysis was to determine the incidence of disc degeneration in patients with surgically treated adolescent idiopathic scoliosis (AIS) and identify the associated risk factors. METHODS: PubMed, EMBASE, Scopus, and Cochrane Collaboration Library databases were searched. The outcomes of interest were the incidence of disc degeneration, SRS-22, and radiological risk factors. The lower instrumented vertebra (LIV) was also evaluated. Fixed effects were used if there was no evidence of heterogeneity. Statistical analysis was performed using Review Manager. RESULTS: A meta-analysis was conducted including nine studies with a total of 565 patients. The analysis revealed that the global incidence of intervertebral disc degeneration in patients with surgically treated AIS patients was 24.78% (95% CI 16.59-32.98%) 10 years after surgery, which significantly increased to 32.32% (95% CI 21.16-43.47% at an average of 13.8 years after surgery. Among patients with significant degenerative disc changes, the SRS-22 functional, self-image, and satisfaction domains showed significantly worse results (MD - 0.25, 95% CI - 0.44 to - 0.05; MD - 0.50, 95% CI - 0.75 to - 0.25; and MD - 0.34, 95% CI - 0.66 to - 0.03, respectively). Furthermore, instrumentation at or above the L3 level was associated with a lower incidence of intervertebral disc degeneration compared to instrumentation below the L3 level (OR 0.25, 95% CI 0.10-0.64). It was also found that the preoperative and final follow-up lumbar curve magnitudes (MD 8.11, 95% CI 3.82-12.41) as well as preoperative and final follow-up lumbar lordosis (MD 0.42, 95% CI - 3.81 to 4.65) were associated with adjacent disc degeneration. CONCLUSIONS: This meta-analysis demonstrated that the incidence of intervertebral disc degeneration significantly increased with long-term follow-up using fusion techniques, reaching up to 32% when patients were 28 years of age. Incomplete correction of deformity and fusion of levels below L3, were identified as negative prognostic factors. Furthermore, patients with disc degeneration showed worse functional outcomes.

A rare case of intervertebral disc calcification combined with ossification of the posterior longitudinal ligament in a child: a case report and literature review.

BACKGROUND: Intervertebral disc calcification (IDC) combined with calcification in children has been sporadically reported, while ossification of the posterior longitudinal ligament (OPLL) in the cervical spine in pediatric patients is exceedingly rare. The aim of this study is to investigate the potential prognosis and outcomes associated with this condition. CASE PRESENTATION: We present an unusual case involving a 10-year-old Chinese child diagnosed with calcified cervical disc herniation and ossification of the posterior longitudinal ligament. Conservative treatment measures were implemented, and at the 1-month and 6-month follow-up, the patient's pain exhibited significant improvement. Subsequent cervical MRI and CT scans revealed the complete disappearance of OPLL and substantial absorption of the calcified disc. During the three-month follow-up, CT demonstrated slight residual disc calcification, however, the patient remained asymptomatic with no discernible limitation in cervical motion. CONCLUSIONS: We conducted a comprehensive review of several cases presenting with the same diagnosis. It is noteworthy that IDC combined with OPLL in children constitutes a rare clinical entity. Despite imaging indications of potential spinal canal occupation, the majority of such cases demonstrate complete absorption following conservative treatment, with OPLL exhibiting a faster absorption rate than calcified discs.

Biomechanical Analysis of Adjacent Segments after Spinal Fusion Surgery Using a Geometrically Parametric Patient-Specific Finite Element Model.

This study aimed to perform a mechanical analysis of adjacent segments after spinal fusion surgery using a geometrically parametric patient-specific finite element model to elucidate the mechanism of adjacent segment degeneration (ASD), thereby providing theoretical evidence for early disease prevention. Fourteen parameters based on patient-specific spinal geometry were extracted from a patient's preoperative computed tomography (CT) scan, and the relative positions of each spinal segment were determined using the image match method. A preoperative patient-specific model of the spine was established through the above method. The postoperative model after L4-L5 posterior lumbar interbody fusion (PLIF) surgery was constructed using the same method except that the lamina and intervertebral disc were removed, and a cage, 4 pedicle screws, and 2 connecting rods were inserted. Range of motion (ROM) and stress changes were determined by comparing the values of each anatomical structure between the preoperative and postoperative models. The overall ROM of the lumbar spine decreased after fusion, while the ROM, stress in the facet joints, and stress in the intervertebral disc of adjacent segments all increased. An analysis of the stress distribution in the annulus fibrosus, nucleus pulposus, and facet joints also showed that not only was the maximum stress in these tissues elevated, but the areas of moderate-to-high stress were also expanded. During torsion, the stress in the facet joints and annulus fibrosus of the proximal adjacent segment (L3-L4) increased to a larger extent than that in the distal adjacent segment (L5-S1). While fusion surgery causes an overall restriction of motion in the lumbar spine, it also causes more load sharing by the adjacent segments to compensate for the fused segment, thus increasing the risk of ASD. The proximal adjacent segment is more prone to degeneration than the distal adjacent segment after spinal fusion due to the significant increase in stress.

Risk factors of adjacent-segment disease after short-segment fusion in patients with de novo degenerative lumbar scoliosis.

OBJECTIVE: Short-segment fusion (SSF) is an effective surgical option for appropriately selected patients with de novo degenerative lumbar scoliosis (DNDLS). Considering that DNDLS is frequently accompanied by multisegment degeneration and potential instability across the entire lumbar segments, it is inevitable that unhealthy segments remain after SSF, thereby increasing the potential risk of adjacent-segment disease (ASD) occurrence. Therefore, the authors aimed to identify the risk factors for ASD in patients with DNDLS who underwent SSF. METHODS: This retrospective study included 80 patients with DNDLS (Cobb angle > 10°) who underwent SSF (1 or 2 levels) between December 2010 and July 2018 with a minimum follow-up duration of 5 years. The participants were divided into two groups: ASD and non-ASD. ASD was defined as clinical ASD rather than radiographic ASD. Various patient and operative variables were compared between the groups. Global and regional radiographic parameters (preoperatively and postoperatively) were also compared between the two groups using plain radiography and MRI. Consequently, univariate and multivariate analyses were conducted to identify the risk factors for ASD occurrence. The receiver operating characteristic (ROC) curve was used to calculate the cutoff values. RESULTS: The mean ± SD age was 67.7 ± 7.2 years at the time of SSF, and there were 62 women (77.5%) enrolled in the study. Thirty patients (37.5%) were in the ASD group and 50 patients (62.5%) were in the non-ASD group. The mean time from the surgery to ASD diagnosis was 34.9 ± 28.2 months in ASD group. Thirteen patients required revision surgery at a mean time of 8.8 ± 7.0 months after ASD occurrence. Multivariate logistic regression analysis demonstrated that preoperative disc wedging angle (OR 1.806, 95% CI 1.255-2.598, p = 0.001), presence of facet tropism (defined as ≥ 10° difference between the facet joint angles of the right and left sides) (OR 5.534, 95% CI 1.528-20.040, p = 0.009), and foraminal stenosis ≥ grade 2 (OR 5.935, 95% CI 1.253-28.117, p = 0.025) were significant risk factors for ASD development. The cutoff value of the preoperative disc wedging angle was calculated to be 2.5° using the ROC curve. CONCLUSIONS: Preoperative disc wedging angle ≥ 2.5°, presence of facet tropism, and foraminal stenosis ≥ grade 2 were identified as significant risk factors for ASD development after SSF in patients with DNDLS.

Does intervertebral disc degeneration in adolescent idiopathic scoliosis correlate with patient-reported pain scores? A review of 968 cases.

PURPOSE: Report the rate and severity of degenerative disc disease (DDD) in non-surgical adolescent idiopathic scoliosis (AIS) patients and correlate these findings with patient-reported symptomatology scores. Additionally, to quantify the rate of concurrent pathological radiological findings in this group. METHODS: This was a retrospective chart review study at a single tertiary centre. AIS patients aged 10-16 who had received a whole spine MRI between September 2007 and January 2019 and who had not received surgical intervention to their spine were included. MRI scan reports were screened to extract those who had evidence of DDD. These were then reviewed by a blinded second reviewer who graded every disc using the Pfirrmann grading system. SRS-22 scores were extracted for patients when available. RESULTS: In total, 968 participants were included in the study. Of these, 93 (9.6%) had evidence of DDD, which was Pfirrmann grade ≥ 3 in 28 (2.9%). The most commonly affected level was L5/S1 (59.1% of DDD cases). A total of 55 patients (5.7%) had evidence of syringomyelia, 41 (3.4%) had evidence of spondylolisthesis (all L5/S1), 14 (1.4%) had bilateral L5 pars defects, and 5 (0.5%) had facet joint degeneration. Spondylolisthesis and bilateral pars defects were more common in patients with DDD identified on MRI scan (p < 0.001 and p = 0.04, respectively). Function (p = 0.048) and pain (p = 0.046) scores were worse in patients with DDD. CONCLUSION: We present a baseline for the rate and severity of DDD in the non-operative AIS cohort. This should assist in decision-making and counselling of patients prior to surgery. LEVEL OF EVIDENCE: III.

Evolution of lumbar degenerative spondylolisthesis with key radiographic features.

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

Association between lumbar intervertebral vacuum phenomenon severity and posterior paraspinal muscle atrophy in patients undergoing spine surgery.

PURPOSE: Intervertebral vacuum phenomenon (IVP) and paraspinal muscular atrophy are age-related changes in the lumbar spine. The relationship between both parameters has not been investigated. We aimed to analyze the correlation between IVP and paraspinal muscular atrophy in addition to describing the lumbar vacuum severity (LVS) scale, a new parameter to estimate lumbar degeneration. METHODS: We analyzed patients undergoing spine surgery between 2014 and 2016. IVP severity was assessed utilizing CT scans. The combination of vacuum severity on each lumbar level was used to define the LVS scale, which was classified into mild, moderate and severe. MRIs were used to evaluate paraspinal muscular fatty infiltration of the multifidus and erector spinae. The association of fatty infiltration with the severity of IVP at each lumbar level was assessed with a univariable and multivariable ordinal regression model. RESULTS: Two hundred and sixty-seven patients were included in our study (128 females and 139 males) with a mean age of 62.6 years (55.1-71.2). Multivariate analysis adjusted for age, BMI and sex showed positive correlations between LVS-scale severity and fatty infiltration in the multifidus and erector spinae, whereas no correlation was observed in the psoas muscle. CONCLUSION: IVP severity is positively correlated with paraspinal muscular fatty infiltration. This correlation was stronger for the multifidus than the erector spinae. No correlations were observed in the psoas muscle. The lumbar vacuum severity scale was significantly correlated with advanced disc degeneration with vacuum phenomenon.

How Does the Slump Sitting Radiograph Increase Proportion of Segmental Instability and Kyphotic Alignment of Lumbar Degenerative Spondylolisthesis?

OBJECTIVE: Clinical and radiographic degenerative spondylolisthesis (CARDS) classification was proposed to differentiate homogenous lumbar degenerative spondylolisthesis (LDS) subgroups. The sitting radiograph exhibited lumbar malalignment with maximum lumbar kyphosis, intervertebral kyphosis, and spondylolisthesis.This study aimed to assess the sitting radiograph for distribution of clinical and radiographic degenerative spondylolisthesis classification, and to elucidate its significance for exhibiting kyphotic alignment (CARDS type D) and segmental instability. METHODS: A cohort of 101 patients with symptomatic lumbar degenerative spondylolisthesis (LDS) between September 2018 and December 2020 were recruited. The distribution and relibility of CARDS classification with or without sitting radiograph was assessed. The translational and angular range of motion and segmental instability was also evaluated. Univariate analysis of variance was used for multiple groups, and the least significant difference for two groups. Kappa consistency test of intrarater and interrater was evaluated for CARDS classification with or without sitting radiograph. Chi-square test was used to compare paried categorical data. RESULTS: Utility of sitting radiographs for CARDS classification revealed higher percentage of type D than that without the sitting radiograph (p < 0.001). The sitting radiograph revealed a larger slip distance than the flexion radiograph (p = 0.003), as well as a lower slip angle than flexion radiograph (p < 0.001). The sitting-supine modality demonstrated the largest translational range of motion compared to the sitting-extension (p < 0.001) and flexion-extension modalities (p < 0.001). The sitting-supine modality showed larger angular range of motion than the flexion-extension modality (p < 0.001). The percentage of flexion, extension, upright, supine, and sitting radiograph to identify translational instability was higher than that without sitting radiograph (p < 0.001), as well as taking angular motion ≥10° as an additional criterion for segmental instability (p < 0.001). CONCLUSION: The CARDS classification was reliable for LDS. The sitting radiograph showed maximal slip distance and kyphotic slip angle. Application of the sitting radiograph was necessary for evaluating segmental instability and kyphotic alignment of LDS.

Relationship between the postoperative variations of paraspinal muscles and adjacent-segment degeneration in patients with degenerative lumbar spinal stenosis after posterior instrumented lumbar fusion.

OBJECTIVE: This study aimed to quantify pre- and postoperative paraspinal muscular variation following posterior lumbar interbody fusion (PLIF) in patients with degenerative lumbar spinal stenosis (DLSS) and measure the association of this variation with adjacent-segment degeneration (ASD). METHODS: Data from 149 patients who underwent L4-S1 PLIF for DLSS were collected. Patients were divided into radiologically confirmed ASD and control groups according to follow-up radiological findings. MRI was performed before surgery and at the last follow-up. Muscular parameters including the relative cross-sectional area (rCSA), relative functional cross-sectional area (rFCSA), relative total cross-sectional area (rTCSA), and fatty infiltration (FI) of the multifidus (MF), erector spinae (ES), and psoas major (PM) muscles were measured on preoperative and follow-up L2-S1 MR images. Logistic regression was used to investigate risk factors for ASD. RESULTS: The rate of radiological ASD was 42.3% at the final follow-up (mean 25.71 ± 8.35 months). At surgical levels, the rFCSA and rTCSA of the MF and ES muscles decreased. The FI of the MF from L2-3 to L5-S1 and ES muscles at L5-S1 significantly increased after surgery, while the rFCSA and rTCSA of the PM muscle increased and its FI decreased. At adjacent levels, the rFCSA and rTCSA of the MF muscle and rTCSA of the ES muscle decreased and the FI of the MF muscle increased postoperatively (p < 0.05), but the rFCSA and rTCSA of the PM muscle increased and its FI decreased (p < 0.05). The FIs of the MF, ES, and PM muscles at adjacent levels significantly differed between the ASD and control groups. Logistic regression analysis indicated that higher BMI (p = 0.002) and FI of the PM muscle at adjacent levels (p = 0.025) were significant risk factors for ASD. CONCLUSIONS: The functional area decreased in the MF and ES muscles and increased in the PM muscle after L4-S1 PLIF. A compensatory postoperative decrease in FI of the PM muscle at the adjacent level was a protective factor for ASD in DLSS patients after PLIF.

MRI characteristics of disc degeneration after condoliase injection in young patients: A consecutive case series.

BACKGROUND: Lumbar disc herniation (LDH) results in low back pain due to nerve root compression caused by nucleus pulposus degeneration. Chemonucleolysis of the nucleus pulposus by injection of condoliase is less invasive than surgery, but may cause disc degeneration. The purpose of the study was to examine outcomes of condoliase injection in patients in their teens and twenties using Pfirrmann criteria on MRI. METHODS: A single-center retrospective study was performed in 26 consecutive patients (19 men, 7 women) who underwent condoliase injection (1 mL, 1.25 U/mL) for LDH and had MRI scans at 3 and 6 months. Cases with and without an increase in Pfirrmann grade at 3 months post-injection were included in groups D (disc degeneration, n = 16) and N (no degeneration, n = 10). Pain was measured on a visual analogue scale (VAS). MRI findings were evaluated using the % change in disc height index (ΔDHI). RESULTS: The mean age of the patients was 21.1 ± 4.1 years and 12 were <20 years old. At baseline, 4, 21 and 1 were in Pfirrmann grades II, III and IV. In group D, no case had a further increase in Pfirrmann grade from 3 to 6 months. Pain significantly decreased in both groups. There were no adverse events. MRI showed a significant decrease in ΔDHI from 100% pre-injection to 89.4 ± 9.7% at 3 months in all cases (p < 0.05). There was a significant recovery in ΔDHI in group D from 3 to 6 months (85.4 ± 9.3% vs. 86.7 ± 9.1%, p < 0.05). CONCLUSIONS: These results suggest that chemonucleolysis with condoliase is effective and safe for LDH in young patients. Progression of Pfirrmann criteria at 3 months post-injection occurred in 61.5% of cases, but disc degeneration showed recovery in these patients. A longer-term study of the clinical symptoms related to these changes is required.

Changes in the centre of rotation and the anterior bone loss of the vertebral body in Mobi-C artificial disc replacement segments after cervical hybrid surgery: a retrospective study.

OBJECTIVE: To examine the short-term efficacy and imaging results of using the Mobi-C in cervical hybrid surgery on 2-level cervical spondylolisthesis. To observe post-operative changes in the flexion-extension centre of rotation (FE-COR) and anterior bone loss (ABL) of the anterior cervical disc replacement (ACDR) segment. METHODS: Forty-two patients (20 males and 22 females, aged 42‒67 years) who underwent cervical hybrid surgery were retrospectively analysed. Their ACDR segment used Mobi-C, and the fusion segment used ROI-C, with a follow-up of 25‒42 months (31.1 ± 4.8 months). The modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and visual analogue scale (VAS) were used to assess clinical outcomes. Pre-operative, 6-month post-operative, and final follow-up radiographs were collected to compare total cervical spine curvature (C2-C7), curvature of the operated segments, range of motion (ROM) in the total cervical spine, operated segmental ROM, ACDR segmental ROM, and operated adjacent segmental ROM. The height of the superior articular process (HSAP), the orientation of zygapophyseal joint spaces (OZJS), and the length of the superior articular surface (LSAS) were measured. The FE-COR of the ACDR segment was measured using the mid-plumb line method. The translation distance of the Mobi-C was measured. The degree of disc degeneration in the adjacent segment, bony fusion of the ACDF segment, and ABL of the upper and lower vertebra of the ACDR segment were observed. RESULTS: In our group, all patients have shown improvements in their postoperative mJOA, NDI, and VAS scores. Overall cervical ROM and surgical segmental ROM decreased (P < 0.05). However, there was no significant decrease in ACDR segmental ROM and upper or lower adjacent segmental ROM compared with pre-operatively (P > 0.05). For FE-COR-X, only the last follow-up compared with pre-surgery showed statistical significance (46.74 ± 7.71% vs. 50.74 ± 6.92%, P < 0.05). For FE-COR-Y, the change was statistically significant at both 6 months post-operation and the final follow-up compared to pre-operation (45.37% ± 21.11% vs. 33.82% ± 10.87%, 45. 37% ± 21.11% vs. 27.48% ± 13.58%, P < 0.05). No significant difference in the Mobi-C translation distance was observed (P > 0.05). Moreover, the difference in HSAP was not statistically significant at each node (P > 0.05). The OZJS and LSAS were significantly different at the final follow-up compared to the pre-operative period (P < 0.05). All the ACDF segments were observed in a stable condition at the final follow-up. Furthermore, 9 of the adjacent segments showed imaging ASD (9/82, 10.98%), and all were present at the last follow-up, of which 6 were mild, and 3 were moderate. Twenty of the 42 Mobi-C segments had no significant ABL (grade 0) 6 months post-operatively (47.62%). Sixteen cases (38.10%) showed mild ABL (grade 1), and 6 cases (14.28%) showed moderate ABL (grade 2). No severe ABL occurred. CONCLUSION: The cervical hybrid surgery using Mobi-C artificial cervical discs can achieve satisfactory results. The Mobi-C segmental FE-COR-X shows a slow forward shift trend, and FE-COR-Y drops noticeably within 6 months post-surgery before stabilizing. It's common to see mild to moderate ABL after cervical hybrid surgery using Mobi-C, and significant progression is unlikely in the short term. Furthermore, changes in the FE-COR after hybrid surgery in the Mobi-C segment might not affect clinical outcomes.