Limited discectomy versus aggressive discectomy by spinal endoscopy with the transforaminal approach for lumbar disc herniation: a retrospective study.

OBJECTIVE: To compare the clinical and radiological outcomes of limited discectomy (LD) and aggressive discectomy (AD) performed via spinal endoscopy using the transforaminal approach in patients with lumbar disc herniation(LDH) METHODS: We conducted a retrospective review of patients who underwent percutaneous endoscopic transforaminal discectomy (PETD) at the L4-L5 lumbar spine segments in our department from January 2017 to December 2020. The follow-up period extended to 24 months postoperatively. Patients were categorized into the LD and AD groups based on the extent of intraoperative disc removal. We retrospectively collected and analyzed clinical and radiological data. RESULTS: The study followed 65 patients, with 36 in the LD group and 29 in the AD group. No statistically significant differences were noted in recurrence rates, the excellent and good Macnab rates, preoperative Disc Height Index (DHI), and preoperative Modic changes between the groups (P >0.05). However, significant differences were observed in operation duration, postoperative DHI and postoperative Modic change (P<0.05). No significant differences in Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores were detected between the groups preoperatively, or one and two years postoperatively (P>0.05). Nevertheless, notable differences in VAS and ODI scores were present one month postoperatively (P<0.05). CONCLUSION: As a conventional surgical method for treating LDH, PETD can achieve satisfactory clinical results in both LD and AD, with no significant variance in recurrence rates. However, AD is associated with longer operation times, and greater postoperative reductions in DHI and greater postoperative Modic changes compared to LD.

Posterior fixation, anterior debridement and bone grafting in the treatment of thoracic and lumbar tuberculosis in children younger than 3 years of age.

PURPOSE: This study aimed to investigate the clinical outcomes of posterior fixation, combined with one- or two-stage anterior debridement and bone grafting in treating children younger than 3 years of age with thoracic and lumbar tuberculosis. METHODS: This was a retrospective study involving 16 young children with thoracic or lumbar tuberculosis. Surgical data were recorded. Frankel Grade was used to assess neurological function. The regional kyphosis angle was measured to evaluate the deformity correction. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were detected to assess the activity of tuberculosis. Bony fusion and complications were also recorded. RESULTS: The mean operation time was 204.4 ± 41.8 min. The mean estimated blood loss was 126.3 ± 94.4 ml. Preoperative Frankel Grade results indicated five patients with Grade C, six with Grade D, and five with Grade E. At the final follow-up, all patients were in Grade E. Twelve patients were brought back to normal spinal alignment and the rest four patients remained kyphotic. There was an improvement of 29.3° ± 18.3° in regional kyphotic angle postoperatively. And the deformity correction was 27.4° ± 19.1° at the final follow-up. ESR and CRP decreased to a normal range at three months follow-up. Bony fusion was achieved in all patients. None of the cases developed fixation failure, pseudoarthrosis, or tuberculosis recurrence. CONCLUSION: Posterior fixation, combined with one- or two-stage anterior debridement and bone grafting, is a safe and effective surgical strategy for treating young children with thoracic and lumbar tuberculosis.

Percutaneous endoscopic lumbar discectomy for single and double segment lumbar disc herniation with sciatic scoliosis in adults: a retrospective study.

OBJECTIVE: Sciatic scoliosis can be seen in patients with lumbar disc herniation. Percutaneous endoscopic lumbar discectomy (PELD) is a common surgical method for the treatment of lumbar disc herniation. The difference between single-segment lumbar disc herniation and double-segment lumbar disc herniation with Sciatic Scoliosis in adults after PELD needs further study. The aim of this study was to compare the imaging features of single-segment and double-segment lumbar disc herniation with Sciatic Scoliosis in adults and to further explore the clinical outcomes of functional improvement and scoliosis imaging parameters of the two groups after PELD. METHODS: Adult patients with lumbar disc herniation with sciatic scoliosis who received PELD from January 2019 to June 2022 were analyzed retrospectively. According to the number of operative segments, the patients were divided into a single-segment group and a double-segment group. Perioperative parameters were observed and compared between the two groups. The Visual Analogue Scale (VAS) score, Oswestry dysfunction index (ODI), Japanese Orthopaedic Association scores (JOA) and imaging parameters of the two groups were recorded and compared before the operation and during the follow-up. RESULTS: A total of 53 patients with single segments and 21 patients with double segments were included in this study. During the follow-up, the VAS score, ODI index and JOA score of the two groups were significantly improved as compared with those before the operation(P < 0. 05). Ninety-two point five percent of single-segment patients and 90.5% of double segment patients returned to normal scoliosis within 12 months after the operation. The operation time, number of intraoperative fluoroscopy times and the amount of intraoperative blood loss in single-segment patients were better than those in double-segment group(P < 0. 05). At the last follow-up, the AVT, CBD and SVA in the double-segment group were 5.2 ± 2.3, 5.1 ± 1.0 and 12.2 ± 3.0 mm, respectively, which were higher than those in the single-segment group (1.9 ± 0.4, 1.1 ± 1.6 and 3.9 ± 2.1 mm) (P < 0. 05). CONCLUSION: PELD is an effective treatment for single-segment and double-segment lumbar disc herniation with Sciatic scoliosis. Double-segment patients can enjoy similar clinical efficacy to single-segment patients, avoiding complications caused by decompression, fusion, and internal fixation. Scoliosis was corrected spontaneously within 12 months after operation, and the sagittal curve was significantly improved in both groups. The improvement of coronal and sagittal balance in double -segment patients may take longer.

MRI-based interpretable radiomics nomogram for discrimination between Brucella spondylitis and Pyogenic spondylitis.

Background: Pyogenic spondylitis (PS) and Brucella spondylitis (BS) are commonly seen spinal infectious diseases. Both types can lead to vertebral destruction, kyphosis, and long-term neurological deficits if not promptly diagnosed and treated. Therefore, accurately diagnosis is crucial for personalized therapy. Distinguishing between PS and BS in everyday clinical settings is challenging due to the similarity of their clinical symptoms and imaging features. Hence, this study aims to evaluate the effectiveness of a radiomics nomogram using magnetic resonance imaging (MRI) to accurately differentiate between the two types of spondylitis. Methods: Clinical and MRI data from 133 patients (2017-2022) with pathologically confirmed PS and BS (68 and 65 patients, respectively) were collected. We have divided patients into training and testing cohorts. In order to develop a clinical diagnostic model, logistic regression was utilized to fit a conventional clinical model (M1). Radiomics features were extracted from sagittal fat-suppressed T2-weighted imaging (FS-T2WI) sequence. The radiomics features were preprocessed, including scaling using Z-score and undergoing univariate analysis to eliminate redundant features. Furthermore, the Least Absolute Shrinkage and Selection Operator (LASSO) was employed to develop a radiomics score (M2). A composite model (M3) was created by combining M1 and M2. Subsequently, calibration and decision curves were generated to evaluate the nomogram's performance in both training and testing groups. The diagnostic performance of each model and the indication was assessed using the receiver operating curve (ROC) with its area under the curve (AUC). Finally, we used the SHapley Additive exPlanations (SHAP) model explanations technique to interpret the model result. Results: We have finally selected 9 significant features from sagittal FS-T2WI sequences. In the differential diagnosis of PS and BS, the AUC values of M1, M2, and M3 in the testing set were 0.795, 0.859, and 0.868. The composite model exhibited a high degree of concurrence with the ideal outcomes, as evidenced by the calibration curves. The nomogram's possible clinical application values were indicated by the decision curve analysis. By using SHAP values to represent prediction outcomes, our model's prediction results are more understandable. Conclusions: The implementation of a nomogram that integrates MRI and clinical data has the potential to significantly enhance the accuracy of discriminating between PS and BS within clinical settings.

The Potential of a CT-Based Machine Learning Radiomics Analysis to Differentiate Brucella and Pyogenic Spondylitis.

Background: Pyogenic spondylitis (PS) and Brucella spondylitis (BS) are common spinal infections with similar manifestations, making their differentiation challenging. This study aimed to explore the potential of CT-based radiomics features combined with machine learning algorithms to differentiate PS from BS. Methods: This retrospective study involved the collection of clinical and radiological information from 138 patients diagnosed with either PS or BS in our hospital between January 2017 and December 2022, based on histopathology examination and/or germ isolations. The region of interest (ROI) was defined by two radiologists using a 3D Slicer open-source platform, utilizing blind analysis of sagittal CT images against histopathological examination results. PyRadiomics, a Python package, was utilized to extract ROI features. Several methods were performed to reduce the dimensionality of the extracted features. Machine learning algorithms were trained and evaluated using techniques like the area under the receiver operating characteristic curve (AUC; confusion matrix-related metrics, calibration plot, and decision curve analysis to assess their ability to differentiate PS from BS. Additionally, permutation feature importance (PFI; local interpretable model-agnostic explanations (LIME; and Shapley additive explanation (SHAP) techniques were utilized to gain insights into the interpretabilities of the models that are otherwise considered opaque black-boxes. Results: A total of 15 radiomics features were screened during the analysis. The AUC value and Brier score of best the model were 0.88 and 0.13, respectively. The calibration plot and decision curve analysis displayed higher clinical efficiency in the differential diagnosis. According to the interpretation results, the most impactful features on the model output were wavelet LHL small dependence low gray-level emphasis (GLDN). Conclusion: The CT-based radiomics models that we developed have proven to be useful in reliably differentiating between PS and BS at an early stage and can provide a reliable explanation for the classification results.

Development and Validation of a Predictive Model to Evaluate the Risk of Dysphagia Following Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: A retrospective study. OBJECTIVE: To investigate the potential risk factors of dysphagia after anterior cervical discectomy and fusion (ACDF) and to establish and validate a prediction model. METHODS: The clinical data of 252 patients who underwent anterior cervical discectomy and fusion in our hospital from January 2018 to October 2020 were retrospectively analyzed and divided into the dysphagia group and the non-dysphagia group according to whether dysphagia occurred after surgery. Age, gender, body mass index, smoking and drinking history, hypertension history, diabetes history, disease duration, placement of Hemovac negative pressure drain, number of segments involved in surgery, whether C4-5/C5-6 segment surgery, incision length, incision position, level of preoperative EAT-10 score, whether preoperative tracheal exercise, and changes in cervical curvature before and after surgery were recorded in both groups. Risk factors for postoperative dysphagia were identified and nomogram prediction models were developed. RESULTS: A total of 252 patients were included in the study, 115 of whom presented with dysphagia within 1 week after anterior cervical fusion. The results of multivariate logistic regression analysis indicated that male gender (OR = .045, 95% CI .223-.889) and whether preoperative tracheal exercise (OR = .260, 95% CI .107-.633) were independent risk factors associated with reduced incidence of postoperative dysphagia. CONCLUSION: The incidence of dysphagia symptoms after anterior cervical decompression and fusion gradually decreased with the extension of follow-up time, and preoperative tracheal exercise and shortening the operation time may help to reduce the occurrence of postoperative dysphagia.

Development and validation of a novel nomogram to predict the risk of the prolonged postoperative length of stay for lumbar spinal stenosis patients.

BACKGROUND: Lumber spinal stenosis (LSS) is the increasingly reason for spine surgery for elder patients since China is facing the fastest-growing aging population. The aim of this research was to create a model to predict the probabilities of requiring a prolonged postoperative length of stay (PLOS) for lumbar spinal stenosis patients, minimizing the healthcare burden. METHODS: A total of 540 LSS patients were enrolled in this project. The outcome was a prolonged PLOS after spine surgery, defined as hospitalizations ≥ 75th percentile for PLOS, including the day of discharge. The least absolute shrinkage and selection operator (LASSO) was used to identify independent risk variables related to prolonged PLOS. Multivariable logistic regression analysis was utilized to generate a prediction model utilizing the variables employed in the LASSO approach. The receiver operating characteristic (ROC) curve's area under the curve (AUC) and the calibration curve's respective curves were used to further validate the model's calibration with predictability and discriminative capabilities. By using decision curve analysis, the resulting model's clinical effectiveness was assessed. RESULTS: Among 540 individuals, 344 had PLOS that was within the usual range of P75 (8 days), according to the interquartile range of PLOS, and 196 had PLOS that was above the normal range of P75 (prolonged PLOS). Four variables were incorporated into the predictive model, named: transfusion, operation duration, blood loss and involved spine segments. A great difference in clinical scores can be found between the two groups (P < 0.001). In the development set, the model's AUC for predicting prolonged PLOS was 0.812 (95% CI: 0.768-0.859), while in the validation set, it was 0.830 (95% CI: 0.753-0.881). The calibration plots for the probability showed coherence between the expected probability and the actual probability both in the development set and validation set respectively. When intervention was chosen at the potential threshold of 2%, analysis of the decision curve revealed that the model was more clinically effective. CONCLUSIONS: The individualized prediction nomogram incorporating five common clinical features for LSS patients undergoing surgery can be suitably used to smooth early identification and improve screening of patients at higher risk of prolonged PLOS and minimize health care.

Application of cement-augmented pedicle screws in elderly patients with spinal tuberculosis and severe osteoporosis: a preliminary study.

OBJECTIVE: Surgical management of elderly patients with spinal tuberculosis and severe osteoporosis is challenging. Cement-augmented pedicle screws (CAPS) have been specifically designed for elderly patients with osteoporotic spines. Herein, we investigated the feasibility of CAPS applied in elderly patients with spinal tuberculosis and severe osteoporosis. METHODS: We retrospectively analyzed data of patients with spinal tuberculosis and severe osteoporosis between January 2017 and January 2021. Surgical data, including surgical duration and intraoperative blood loss, were recorded. Radiological parameters, such as correction of regional kyphotic angle and screw loosening, were also evaluated. Additionally, visual analog scores (VAS) and Oswestry disability index (ODI) were used to evaluate back pain and functional recovery, respectively. Erythrocyte sedimentation (ESR) and C-reactive protein (CRP) concentrations were detected to assess tuberculosis activity. The presence of complications and fusion rate was also assessed. RESULTS: A total of 15 patients were included in this study. The surgical duration was 263.0 ± 56.2 min, with an average blood loss of 378.7 ± 237.0 ml. The correction of regional kyphotic angle was 12.4° ± 15.0°, and it was well maintained until the final follow-up. The mean VAS decreased from 6.0 ± 1.2 points to 0.5 ± 0.6 points, and ODI reduced from 37.8% ± 7.6% to 8.3% ± 2.8% (P < 0.01). At the final follow-up, ESR and CRP levels were within normal range. Bony fusion occurred in all patients, with an average fusion duration of 8.8 ± 1.5 months. No cases of pedicle screw pullout, screw loosening, or pseudoarthrosis occurred. Tuberculosis recurrence and dissemination were not observed during the follow-ups. CONCLUSIONS: CAPS fixation is an effective and safe technique to achieve solid fixation and favorable clinical outcomes in elderly patients with spinal tuberculosis and severe osteoporosis.

Surgical Treatment for Displaced Odontoid Synchondrosis Fracture: A Retrospective Case Series Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: Odontoid synchondrosis fracture is rare, and there is a paucity of literature on its surgical treatments. This case series study analyzed patients treated with C1 to C2 internal fixation with or without anterior atlantoaxial release and discussed the clinical effectiveness of the procedure. METHODS: Data were retrospectively collected from a single-center cohort of patients who had undergone surgical treatments for displaced odontoid synchondrosis fracture. The operation time and blood loss volume were recorded. Neurological function was assessed and classified using the Frankel grades. The odontoid process tilting angle (OPTA) was used to evaluate fracture reduction. Fusion duration and complications were also analyzed. RESULTS: Seven patients (1 boy and 6 girls) were included in the analysis. Three patients underwent anterior release and posterior fixation surgery, and the other 4 underwent posterior-only surgery. The fixation segment was C1 to C2. The average follow-up period was 34.7 ± 8.5 months. The average operation time was 145.7 ± 45.3 min, with an average blood loss volume of 95.7 ± 33.3 mL. The OPTA was corrected from 41.9° ± 11.1° preoperative to 2.4° ± 3.2° at the final follow-up (P < .05). The preoperative Frankel grade of 1 patient was grade C, of 2 patients was grade D, and of 4 patients was grade E. The neurological function of the patients in grade C and grade D recovered to grade E at the final follow-up. None of the patients developed a complication. All the patients achieved odontoid fracture healing. CONCLUSIONS: Posterior C1 to C2 internal fixation with or without anterior atlantoaxial release is a safe and effective method for treating young children with displaced odontoid synchondrosis fracture.

Extensive hydatid cysts involving the lumbosacral vertebrae and pelvis.

•A patient with typical hydatid cysts involving both lumbosacral vertebrae and pelvis is presented in this paper.•Conservative treatment with antiparasitic medication may improve symptoms.•Surgical treatment followed by antiparasitic chemotherapy may reduce the relapse rate of bone hydatid cysts.

Evaluation of preoperative calculation methods of osteotomy size in ankylosing spondylitis with thoracolumbar or lumbar kyphosis.

BACKGROUND: To evaluate the accuracy of different preoperative calculation methods of osteotomy size in ankylosing spondylitis with thoracolumbar or lumbar kyphosis and analyze its clinical significance. METHODS: Twenty-two cases of AS patients with thoracolumbar or lumbar kyphosis, from January 2015 to December 2018, who underwent one-level SPO surgery in our hospital, were retrospectively reviewed. The sagittal parameters were measured at pre-operation and last follow up using Surgimap software, and theoretical values of sagittal parameters were calculated according to pre-operative PI. The osteotomy angles of different methods were measured using Surgimap software. Paired t test was used to for the statistical analysis. RESULTS: The mean follow-up time of all patients was 30.00 [Formula: see text] 3.56 months. The osteotomy sites were located at T12 in 3 cases, L1 in 6 cases, L2 in 9 cases, and L3 in 4 cases. Compared to pre-operative sagittal parameters, post-operative PT, SS, LL, and SVA were significantly improved (P [Formula: see text] 0.05). Compared to the OVA (46.57 [Formula: see text] 2.32 [Formula: see text]), there was a significantly larger angle predicted by Surgimap method (53.80 [Formula: see text] 9.79 [Formula: see text]), CAM-HA method (56.61 [Formula: see text] 8.58 [Formula: see text]), and HP-HA method (60.07 [Formula: see text] 13.58 [Formula: see text]), respectively (P [Formula: see text] 0.05). But no significant difference was found between the postoperative osteotomy angle and those of SFA method (51.24 [Formula: see text] 12.14 [Formula: see text]) and FBI method (48.08 [Formula: see text] 12.49 [Formula: see text]) (P [Formula: see text] 0.05). CONCLUSION: For AS patients with thoracolumbar or lumbar kyphosis, the SFA method, FBI method, and Surgimap method can be used to predict the osteotomy angle precisely, however, considering the rationality of parameter settings and the operability, SFA method is relatively more suitable for such population.

One-stage posterior surgery combined with anti-Brucella therapy in the management of lumbosacral brucellosis spondylitis: a retrospective study.

BACKGROUND: This study aimed to assess the clinical efficacy of one-stage posterior surgery combined with anti-Brucella therapy in the treatment of lumbosacral brucellosis spondylitis (LBS). METHODS: From June 2010 to June 2020, the clinical and radiographic data of patients with LBS treated by one-stage posterior surgery combined with anti-Brucella therapy were retrospectively analyzed. The visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) and Oswestry Disability Index scores (ODI) were used to evaluate the clinical outcomes. Frankel's classification system was employed to access the initial and final neurologic function. Fusion of the bone grafting was classified by Bridwell's grading system. RESULTS: A total of 55 patients were included in this study with a mean postoperative follow-up time of 2.6 ± 0.8 years (range, 2 to 5). There were 40 males and 15 females with a mean age of 39.8 ± 14.7 years (range, 27 to 57). The Brucella agglutination test was ≥ 1:160 in all patients, but the blood culture was positive in 43 patients (78.1%). A statistical difference was observed in ESR, CRP, VAS, ODI, and JOA between preoperative and final follow-up (P < 0.05). Neurological function was significantly improved in 20 patients with preoperative neurological dysfunction after surgery. According to Bridwell's grading system, the fusion of bone grafting in 48 cases (87.2%) was defined as grade I, and grade II in 7 cases (12.7%). None of the infestation recurrences was observed. CONCLUSION: One-stage posterior surgery combined with anti-Brucella therapy was a practical method in the treatment of LBS with severe neurological compression and spinal sagittal imbalance.

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

OBJECTIVE: To analyze the clinical efficacy of transforaminal lumbar interbody fusion (TLIF) in the treatment of continuous double-level lumbar spondylolisthesis with sagittal imbalance. METHODS: The clinical data of 36 patients with double-level spondylolisthesis treated with TLIF were included and divided into L3/L4 double spondylolisthesis group and L4/L5 double spondylolisthesis group according to the site of spondylolisthesis. The sagittal parameters of the patients were measured by standing anteroposterior and lateral X-rays of the whole spine, and the visual analogue scale (VAS) for lumbar and lower limb pain, Japanese Orthopaedic Association (JOA), and Oswestry Disability Index (ODI) were recorded. The imaging parameters and clinical parameters of the patients before surgery, after surgery, and at the last follow-up were compared and statistically analyzed. RESULTS: A total of 36 patients were included in the study and all had sagittal imbalance. Among them, there were 21 cases of L3 and L4 spondylolisthesis, 6 males and 15 females, with an average age of 64.7 ± 9.4 years; there were 15 cases of L4 and L5 spondylolisthesis, 4 males and 11 females, with an average age of 66.5 ± 8.0 years. 36 patients completed the operation, the operation time was 190.28 ± 6.12 min, and intraoperative blood loss was 345 ± 11 ml. Compared with preoperative, there were significant differences in SVA, TPA, T1-SPi, LL, PT, SS, PI-LL, SD, SA, and SP between patients after surgery and at the last follow-up (P < 0.05). Compared with preoperative, VAS score, JOA score, and ODI index of waist and lower limbs were significantly improved after the operation and at the last follow-up, and there was a significant difference (P < 0.05). CONCLUSION: TLIF can effectively relieve the symptoms of patients with continuous double-level lumbar spondylolisthesis, restore lumbar lordosis and sagittal spinal sequence, and improve the quality of life of patients.

Ulinastatin attenuates spinal cord injury by targeting AMPK/NLRP3 signaling pathway.

The AMPK and NLRP3 inflammasome signaling pathways are reported to participant in the inflammatory responses following spinal cord injury (SCI). Ulinastatin (ULI) is a urinary trypsin inhibitor with excellent anti-inflammatory effects, but the functions of ULI on SCI are rarely reported. Hence, this study was designed to investigate whether ULI could modulate SCI through regulating the AMPK/NLRP3 signaling pathway. Cell Counting Kit-8 (CCK-8) assays were used to investigate whether ULI had cytotoxic effects on BV-2 cells. Basso-Beattie-Bresnahan (BBB) scale, spinal cord water content detection, hematoxylin-eosin (HE) and Nissl stainings were used to investigate the protective effects of ULI on rat SCI. The expressions of inflammatory cytokines were detected by ELISA and RT-qPCR. The expressions of key proteins of AMPK and NLRP3 inflammasome were analyzed by western blot. The CCK-8 assays indicated that ULI did not significantly influence the viability of BV-2 cells at various concentrations below 10,000 U/ml. It was witnessed that ULI could dramatically inhibit the activation of NLRP3 inflammasome via activating the AMPK signaling pathway, thus relieving inflammatory responses. Besides, the in vivo experiment suggested that treatment with ULI remarkably relieve spinal cord edema, ameliorated spinal cord tissue architecture, and improved neurological function following SCI. The findings indicate that ULI significantly ameliorates neurological function following SCI by regulating the AMPK/NLRP3 inflammasome signaling pathway.

Pedicle subtraction osteotomy for the corrective surgery of ankylosing spondylitis with thoracolumbar kyphosis: experience with 38 patients.

OBJECTIVE: To evaluate the sagittal parameters and clinical outcome of pedicle subtraction osteotomy (PSO) for the treatment of ankylosing spondylitis (AS) combined with thoracolumbar kyphosis. METHODS: The clinical data of 38 patients with AS combined with thoracolumbar kyphosis who underwent PSO were enrolled and divided into the lumbar lordosis group and the lumbar kyphosis group according to the preoperative sagittal morphology. They were subdivided into the lumbar lordosis T12 group, lordosis L1 group, kyphosis L2 group, and kyphosis L3 group. The spine sagittal parameters were compared between the preoperative and the postoperative. Outcome evaluation was performed by the Japanese Orthopedic Association (JOA) score, visual analogue scale (VAS), and the Oswestry Disability Index (ODI). RESULTS: A total of 38 patients with AS combined with thoracolumbar kyphosis were successfully treated by PSO, with a mean follow-up time of 26.9 ± 11.9 months. There were 30 males and 8 females with a mean age of 41.6 ± 7.1 years. Twenty patients consisted in the lumbar lordosis group and 18 patients in the lumbar kyphosis group. GK, SVA, and CBVA were improved significantly (P < 0.05) at the final follow-up between the lumbar lordosis T12 group and the L1 group. Patients in the lumbar kyphosis L2 group and L3 group all received satisfactory, including LL, GK, and SVA (P < 0.05). There was no statistically significant difference in the preoperative TK, GK, SVA, PT, and PI between the lumbar lordosis and lumbar kyphosis groups (P > 0.05). Postoperative complications occurred in three cases. CONCLUSION: PSO was a practical method for the treatment of patients with AS combined with thoracolumbar kyphosis. PSO at L3 was recommended to be selected for the lumbar kyphosis to obtain greater SVA correction. CBVA of single-segment PSO may be significantly lower than the two-segment PSO in the management of patients with kyphosis of lower CBVA.

Cadaveric study of anatomical measurement of isthmus parameters of lumbar spine to guide cortical bone screw placement.

OBJECTIVE: To reduce surgical exposure and improve accuracy, this study evaluated the anatomical distance parameter D (including D1, D2, and D3) of the lumbar isthmus for cortical bone screw insertion. METHODS: A total of 25 structurally complete lumbar dry specimens were used for lumbar anatomy measurements. The six cadaver specimens were divided into upper and lower parts on the plane of the T11-T12 vertebrae, and we use the lower parts. Therefore, six lumbar wet specimens and another four complete lumbar dry specimens were selected. The lumbar isthmus tangent point was considered a coordinate origin, and the insertion point was determined through translating the distance of D1 value to the midline of the vertebral body horizontally and then vertically moved toward inferior board of the transverse process with the distance of D3 value. RESULTS: In four dry and six wet intact lumbar specimens, cortical bone screws were placed according to the average value of the isthmus parameter D. A total of 100 trajectories were verified in specimens by X-ray and computed topography scan to evaluate the safety, accuracy, and feasibility of the surgical use of isthmus parameter D. Using this parameter, the rates of excellent screw placement were 95% (38/40) in four dry specimens and 88.7% (53/60) in six wet specimens. CONCLUSION: The isthmus parameter D is easier to use by the operator, which can improve surgical accuracy and reduce operation time. LEVEL OF EVIDENCE: Level IV, prospective study.