European Spine Journal

Yamauchi, Ippei; Nakashima, Hiroaki; Ito, Sadayuki; Segi, Naoki; Ouchida, Jun; Morita, Yoshinori; Ode, Yukihito; Nagatani, Yasuhiro; Okada, Yuya; Tauchi, Ryoji; Ohara, Tetsuya; Kawakami, Noriaki; Imagama, Shiro

2024 European Spine Journal

doi: 10.1007/s00586-024-08519-9pmid: 39653853

PurposeTo evaluate the complications and postoperative outcomes of implant removal after posterior fixation in adolescent idiopathic scoliosis.MethodsWe retrospectively reviewed the data of patients who underwent implant removal after posterior corrective fixation for adolescent idiopathic scoliosis between 2002 and 2014. Complications were evaluated in the 116 patients who underwent implant removal at their choice. Radiological evaluations were performed and analyzed in 71 patients who were followed up for > 2 years after implant removal. Moreover, the patients were divided into two groups: those with increased thoracic kyphosis after implant removal and those without.ResultsOverall, 14 of the 116 patients had complications. Two of the three patients with fractures required reoperation. Radiological examination revealed no significant difference in the scoliosis curvature in the coronal plane after implant removal. In the sagittal plane, the lowest instrumented vertebral tilt, cervical lordosis, T1 slope, T1–12 kyphosis angle, and T5–12 kyphosis angle were significantly increased. Moreover, patients with an increased T5–12 kyphosis angle after implant removal had greater pelvic incidence (PI) and sacral slope (SS) before implant removal.ConclusionThe prevalence of complications after implant removal in adolescent idiopathic scoliosis was 12.1%. Spinal alignment is more variable in the sagittal plane than in the coronal plane, and patients with increased thoracic kyphosis after implant removal have greater preoperative PI and SS. Sufficient preoperative explanation is necessary if a patient wishes to undergo implant removal.

Tanishima, Shinji; Mihara, Tokumitsu; Takeda, Chikako; Fujiwara, Satoshi; Nagashima, Hideki

2024 European Spine Journal

doi: 10.1007/s00586-024-08575-1pmid: 39633186

Yang, Jin; Zhang, Shu-Bao; Yang, Shuo; Ge, Xiao-Yong; Ren, Chang-Xu; Wang, Shan-Jin

2024 European Spine Journal

doi: 10.1007/s00586-024-08579-xpmid: 39616589

BackgroundAdjacent vertebral fracture (AVF) is a frequent complication following percutaneous vertebral augmentation (PVA). While radiomics is widely utilized in the field of spinal medicine, its application for assessing the risk of AVF in post-PVA patients remains limited.ObjectiveWe aim to develop and validate predictive models using machine learning algorithms for radiomics and clinical risk factors to assess the risk of AVF after PVA.Materials and methodsThis retrospective study included 158 patients with osteoporotic vertebral compression fractures who underwent PVA at our hospital, of which 48 patients had AVF within 2 years. The patients were divided into train and test cohorts in a ratio of 7:3. Radiomics features of the surgically intervened vertebrae were extracted from CT images, and selected using Mann–Whitney U-test and LASSO regression to construct a radiomic signature. Machine learning algorithms (SVM and LR) were then employed to integrate the radiomics signature with clinical data to develop predictive models. The performance of the model was assessed using Receiver Operating Characteristic (ROC) curves and calibration curves.ResultsNine optimal radiomics features were selected to form the radiomics model, while five clinical features were identified for the clinical model. The AUCs of the radiomics, clinical, and combined models developed using the SVM algorithm were 0.77, 0.77, and 0.83 on the test cohort, and those of the LR algorithm were 0.78, 0.81, and 0.86.ConclusionRadiomics and machine learning modeling using postoperative CT images demonstrate noteworthy capability in assessing the risk of AVF following PVA.

Salzer, Elias; Gorgin Karaji, Zahra; van Doeselaar, Marina; Tryfonidou, Marianna A.; Ito, Keita

2024 European Spine Journal

doi: 10.1007/s00586-024-08589-9pmid: 39633187

PurposeLimited nutrient transport is hypothesized to be involved in intervertebral disc (IVD) degeneration. It is widely recognized that the dominant mode of transport of small molecules such as glucose is via diffusion, rather than convection. However, recent findings suggest a role for convection-induced by fast (motion-related) and slow (diurnal) dynamic loading in molecular transport of even such small solutes. The aim of this study was to investigate whether fluid exchange induced by simulated physiological loading (composed of both fast cyclic or slower diurnal loading) can influence the molecular transport of a small molecule through the cartilage endplate (CEP) into the nucleus pulposus (NP) of IVDs. MethodsThe molecular transport of fluorescein through the CEP and into the NP was studied in a bovine CEP/NP explant model and loading was applied by an axial compression bioreactor. The loaded explants (convection and diffusion) were compared to unloaded explants (diffusion alone).ResultsIn the initial 24 h, there were no differences between loaded and unloaded explants, indicating that convection did not enhance molecular transport of small solutes over diffusion alone. Notably, after 48 h which corresponds to two complete diurnal cycles of tissue compression, fluid exudation/imbibing and redistribution, the fluorescein concentration was significantly increased in the top and bottom layer of the explant, when compared to the unloaded explant.ConclusionsSlower diurnal cyclic compression of the IVD might enhance the transport of small molecules into the IVD although it could not be discerned whether this was due to diffusion/convection or a combination.

Zijlstra, Hester; Kuijten, R. H.; Bhimavarapu, Anirudh V.; Lans, Amanda; Cross, Rachel E.; Alnasser, Ahmad; Karhade, Aditya V.; Verlaan, Jorrit-Jan; Groot, Olivier Q.; Schwab, Joseph H.

2024 European Spine Journal

doi: 10.1007/s00586-024-08588-wpmid: 39638884

PurposeThe SORG-MLA was developed to predict 90-day and 1-year postoperative survival in patients with spinal metastatic disease who underwent surgery between 2000 and 2016. Due to the constant changes in treatment methods, it is essential to perform temporal validation with a recent patient population. Therefore, the purpose of this study was to validate the Skeletal Oncology Research Group machine learning algorithms (SORG-MLA) using a contemporary patient cohort.MethodsThis retrospective cohort study investigated patients who received surgical treatment for spinal metastases between January 2017 and July 2021 in two tertiary care centers in the US. Eighteen input variables needed for the SORG-MLA were collected including primary tumor, Eastern Cooperative Oncology Group (ECOG) Performance Status, and nine preoperative laboratory values. Outcomes were defined as mortality at 90-day and 1-year postoperative. Performance was assessed using calibration, discrimination, overall performance, and decision curve analysis.ResultsIn total, 464 patients were included. The validation cohort varied from the development cohort in multiple variables. Despite these differences, the SORG-MLA continued to perform well on calibration, discrimination (area under the receiver operating characteristic curve [AUC] 0.81 (95% confidence interval [CI], 0.77–0.86) for 90-day, AUC 0.75 (95% CI, 0.71–0.80) for 1-year), Brier score, and decision curve analyses.ConclusionsIn spite of recent progress in treating spinal metastases, SORG-MLA for survival in patients with spinal metastatic disease continued to perform well on temporal validation. However, updating the models using a contemporary patient cohort and stratifying by primary tumor could further improve the performance.

Fang, Weijing; Wang, Zhan

2024 European Spine Journal

doi: 10.1007/s00586-024-08604-zpmid: 39641802

The letter responds to a study on the role of erector spinae muscle quality in surgical decision-making for lumbar spondylolisthesis. It highlights the potential of paraspinal muscle fatty infiltration as a predictive factor, suggesting that early rehabilitation targeting these muscles may reduce the need for surgery. The authors propose improvements for future research, such as using advanced MRI techniques for better fat infiltration assessment, controlling patient activity levels, and incorporating multidimensional imaging analyses with machine learning. These advancements could support more personalized treatment strategies for lumbar spondylolisthesis.

Lee, Hyung Rae; Lee, Seung Yup; Seong, Hyukjune; Yang, Jae Hyuk

2024 European Spine Journal

doi: 10.1007/s00586-024-08563-5pmid: 39625659

PurposeThis study determined the prevalence of cauda equina clumping among patients with Schizas grade C or higher central stenosis after decompression and compared the radiographic and clinical outcomes between patients with and without clumping.MethodsWe conducted a single-center retrospective cohort study involving 98 patients who underwent biportal endoscopic spine surgery between January 2019 and June 2022. Based on postoperative magnetic resonance imaging findings, the patients were divided into the clumping (n = 40) and non-clumping (n = 58) groups. Clinical outcomes were assessed using the visual analog scale for back and leg pain, Oswestry Disability Index (ODI), and EuroQol 5-Dimension (EQ-5D-5 L) questionnaire at 1, 3, 6, and 12 months postoperatively. Radiographic evaluations included measuring the cross-sectional area of the dural sac preoperatively and 1 month postoperatively using the PACS software.ResultsPostoperative cauda equina clumping was observed in 40.8% of the patients. Despite an average dural sac expansion of approximately 270%, the clumping group exhibited significantly higher radiating pain at 3 and 6 months (p < 0.05) than the non-clumping group. The ODI and EQ-5D scores were worse in the clumping group at 3 months (p < 0.05). At 12 months postoperatively, differences in clinical outcomes between the two groups were not significant. Patients in the clumping group required longer duration of postoperative medication than those in the non-clumping group (p = 0.024).ConclusionPost-decompression cauda equina clumping is commonly observed in patients with severe lumbar stenosis and impacts intermediate-term clinical recovery. Although long-term outcomes at 1 year are similar, tailored postoperative care is essential for patients exhibiting clumping to effectively manage prolonged symptoms.

Sun, Rosa; Ramadan, Abdelmageed Abdelrahman; Nazar, Thaaqib; Abbas, Ghayur; Andalib, Amin; Majeed, Azam; Dhir, Jasmeet; Czyz, Marcin

2024 European Spine Journal

doi: 10.1007/s00586-024-08591-1pmid: 39625658

PurposeCauda Equina Syndrome (CES) is a rare surgical emergency. The implications for loss of quality of life through delayed management are high, though no clinical symptom is pathognomonic in its diagnosis. We describe how machine learning based algorithms can be used in triaging patients with suspected CES (CES-S).MethodsData of 499 patients who underwent MRI scan for CES-S was collected for demographics, red flag symptoms and radiological outcome. The dataset was used to train the machine learning algorithm in predicting MRI-derived diagnosis of CES. In the testing phase output predictions and Confidence of Prediction (CoP) were recorded for each case and further analysed.ResultsOf 499 patients, 12 (2.4%) had positive radiological outcomes for CES. Patients were divided into two subgroups based on their CoP: high (< 0.9) and low (< 0.9). High CoP was observed in 482 (96.6%) cases. In this group all predictions were correct: 476 negative and 6 positives. Low CoP was observed in 17 (3.4%) cases, of which 6 predictions were incorrect - false negatives. Performing MRI scans only in cases with high CoP positive predictions and all low CoP cases would reduce scans to 5% of the original number.ConclusionWith our dataset, the trained algorithm demonstrated the potential for safely reducing the number of emergency MRI scans by over 95%. Prior to the wide clinical application, large volume prospective data is needed for continuous training of the algorithm, in order to improve accuracy and confidence of prediction.

Chen, Dingbang; Shao, Tianxiang; Zhu, Haocheng; Gao, Xin; Huang, Quan; Yang, Xinghai; Jia, Qi; Xiao, Jianru

2024 European Spine Journal

doi: 10.1007/s00586-024-08601-2pmid: 39653854

BackgroundAlthough many studies have reported clinical outcomes of spinal ependymoma (SE) patients after gross total resection (GTR), the data about the patient reported outcomes of the quality of life (PRO-QOL) was limited.PurposeThis study investigated the recovery process of PRO-QOL and explored the possibility of predicting the recovery of postoperative QOL by preoperative clinical indicators.MethodsA retrospective analysis was performed in 71 SE patients who underwent GTR in our center from 2016 to 2022. The PRO-QOL data were collected by questionnaire, which included the EuroQol 5-Dimensions 5-Levels (EQ-5D-5 L) scale and visual pain analogue score (VAS). Factors affecting postoperative PRO-QOL deterioration was assessed by the univariate and multivariate analyses.Results71 SE patients who undergone GTR were included and followed by mean of 36 months (range 27–58). The overall PRO-QOL recovered to a stable level 6 months after surgery, but the ability of self-care, as one of the dimensions of QOL, continued to improve up to one year after surgery. 21 (29.6%) patients reported that their QOL became worse at one year after surgery. The result of statistical analysis suggested that preoperative Modified McCormick Scale (MMS), the number of segments involved by the tumor and preoperative VAS score were identified as main preoperative variables for predicting QOL deterioration.ConclusionFrom the perspective of PRO-QOL, neurological rehabilitation should be continued for at least 6–12 months after GTR to the SE patients. For the preoperative patients with severe neurological damage, long-level intraspinal tumor and low VAS score, more cautious surgical considerations, more perioperative attention and earlier neurological intervention are necessary.

Godino, Oscar; Fernandez-Carballal, Carlos; Català, Ignasi; Moreno, Ángela; Rimbau, Jordi Manuel; Alvarez-Galovich, Luís; Roldan, Héctor

2024 European Spine Journal

doi: 10.1007/s00586-024-08595-xpmid: 39648196

PurposeThe aim of this study was to evaluate the performance and safety of a new hernia blocking system (HBS), implanted after a limited discectomy, to prevent recurrence of lumbar disc herniation.MethodsProspective, multicenter (6 sites), cohort clinical investigation. Thirty patients with a postero-lateral disc herniation between L4-S1 and large annular defects (> 6 mm wide), who underwent a limited discectomy and were treated with a new HBS (DISC care, NEOS Surgery S.L.), were included.This article presents details about the investigational device, its surgical technique, intraoperative parameters, and up to 6 months follow-up outcomes. The primary endpoint of the study was to assess the incidence of early symptomatic reherniation. In addition, disc height, leg and back pain (NRS 0–10), Oswestry Disability Index (ODI), quality of life (EQ-5D-5L) and device safety, were evaluated. Clinicaltrials.gov: NCT04188236; date: 27th November 2019.ResultsThirty patients (43.3% female, 41.7 ± 10.9 years) were implanted with the device under evaluation in a mean of 16 ± 9.6 min. Six months after surgery, no symptomatic reherniation was detected and disc height was maintained in all patients included. All patients had a significant reduction in leg pain (> 2 points in the NRS), 92.9% improved > 15 points in the ODI and 82.6% significantly improved their quality of life (≥ 12 points in EQ VAS score). No product-related serious adverse events nor reoperations occurred.ConclusionsThe implantation of an HBS is a feasible and safe procedure that prevents early disc herniation recurrence in patients at high risk of reherniation.