Effects of pedicle subtraction osteotomy on aortic morphology and hemodynamics in ankylosing spondylitis with kyphosis: a finite element analysis study.

Osteotomy can correct kyphosis, restore the spinal sequence, and restore the healthy appearance of a patient. However, the aorta is stretched during pedicle subtraction osteotomy (PSO), and some surgeons are concerned about aortic injury. We used finite element analysis to construct an aortic model to simulate hemodynamic changes during osteotomy. 16 patients with ankylosing spondylitis kyphosis who had undergone a two-level osteotomy at the L1 and L3 levels was included in this study. Aortic computed tomography angiography (CTA) was performed, and a 3D image model was constructed. The length, transverse diameter, and curvature of the aorta were used to evaluate morphological changes. Finite element analysis was used to analyze the changes in aortic fluid dynamics. Blood pressure, wall shear stress, and blood flow velocity were compared pre- and postoperatively. The overall length of the aorta before surgery was 424.3 ± 42.9 mm, and the overall length of the aorta after surgery was 436.2 ± 54.8 mm. The aortic curvature decreased from 0.27 ± 0.13 to 0.17 ± 0.09. The mean transverse diameter of the aorta did not change (19.3 ± 6.6 vs. 19.2 ± 7.4 mm, P > 0.05). The blood flow velocity (2.8 ± 1.1 vs. 1.5 ± 0.8 m/s, P < 0.05), blood pressure (6.6 ± 1.7 vs. 4.3 ± 1.2 Kpa, P < 0.05), and wall shear stress (47.6 ± 17.3 vs. 22.3 ± 8.6, P < 0.05) at the T10-L4 level decreased postoperatively. Changes in LL were significantly correlated with changes in ld, dc, blood flow velocity, blood pressure and wall shear stress (ld : r = 0.713, P < 0.001; dc: r = 0.626,P = 0.010; blood flow velocity: r= - 0.541, P = 0.041; blood pressure: r = - 0.601, P = 0.016; wall shear stress: r= - 0.594, P = 0.027). The aorta was stretched, and its curvature decreased. The mean transverse diameter of the aorta did not change. Blood flow velocity, blood pressure, and wall shear stress decreased after surgery. Our study provides hemodynamic support for the possible cardiovascular benefits of osteotomes.

The impact of halo-pelvic traction on sagittal kyphosis in the treatment of severe scoliosis and kyphoscoliosis.

BACKGROUND: Halo-pelvic traction (HPT) is acknowledged for enhancing pulmonary function and reducing neurological complications in severe and rigid scoliosis and kyphoscoliosis. While its role in improving coronal balance is established, its impact on sagittal kyphosis remains under-researched. This study aims to assess HPT's effects on sagittal alignment in these conditions. METHODS: A retrospective review of 37 patients with severe and rigid scoliosis or kyphoscoliosis was conducted to evaluate HPT's efficacy. The analysis focused on the impact of HPT on coronal and sagittal parameters, pulmonary function tests (PFTs) and complications. Radiographic assessments included main cobb angle in coronal, sagittal major kyphosis. RESULTS: HPT was applied for an average of 2.9 months, significantly reducing the primary coronal curve from 127.7°±30.3° to 74.9°±28.3° (P < 0.05), achieving a 41.3% correction rate. Sagittal kyphosis correction was more pronounced, with angles decreasing from 80.4°±26.4° to 41.3°±24.4° (P < 0.05), resulting in a 48.6% correction rate. Pulmonary function tests showed improvements in forced vital capacity (FVC) (from 1.32 ± 0.91 to 1.55 ± 0.83) and forced expiratory volume in 1 s (FEV1) (from 1.03 ± 0.76 to 1.28 ± 0.72), with percentage predicted values also increasing (FVC%: 40.4%±24.3-51.4%±23.1%; FEV1%: 37.8%±25.2-48.1%±22.7%; all P < 0.05). CONCLUSION: HPT effectively reduces spinal deformity severity and improves pulmonary function in patients with severe and rigid scoliosis and kyphoscoliosis. Sagittal kyphosis correction was notably greater than coronal scoliosis correction. The correlation between PFT improvements and coronal curve adjustments suggests that correcting the coronal Cobb angle is pivotal for pulmonary function enhancement.

Differences in cervical sagittal parameters and muscular function among subjects with different cervical spine alignments: a surface electromyography-based cross-sectional study.

Background: We analyzed cervical sagittal parameters and muscular function in different cervical kyphosis types. Methods: This cross-sectional study enrolled subjects with cervical spine lordosis (cervical curvature < -4°) or degenerative cervical kyphosis (cervical curvature > 4°), including C-, S-, and R-type kyphosis. We recorded patients' general information (gender, age, body mass index), visual analog scale (VAS) scores, and the Neck Disability Index (NDI). Cervical sagittal parameters including C2-C7 Cobb angle (Cobb), T1 slope (T1S), C2-C7 sagittal vertical axis (SVA), spino-cranial angle (SCA), range of motion (ROM), and muscular function (flexion-relaxation ratio (FRR) and co-contraction ratio (CCR) of neck/shoulder muscles on surface electromyography). Differences in cervical sagittal parameters and muscular function in subjects with different cervical spine alignments, and correlations between VAS scores, NDI, cervical sagittal parameters, and muscular function indices were statistically analyzed. Results: The FRR of the splenius capitis (SPL), upper trapezius (UTr), and sternocleidomastoid (SCM) were higher in subjects with cervical lordosis than in subjects with cervical kyphosis. FRRSPL was higher in subjects with C-type kyphosis than in subjects with R- and S-type kyphosis (P < 0.05), and was correlated with VAS scores, Cobb angle, T1S, and SVA. FRRUTr was correlated with NDI, SCA, T1S, and SVA. FRRSCM was correlated with VAS scores and Cobb angle. CCR was correlated with SCA and SVA. Conclusion: Cervical sagittal parameters differed among different cervical kyphosis types. FRRs and CCRs were significantly worse in R-type kyphosis than other kyphosis types. Cervical muscular functions were correlated with cervical sagittal parameters and morphological alignment.

An effective strategy for treatment of severe kyphosis secondary to ankylosing spondylitis: one-level modified osteotomy combined with shoulders lifting correction method.

BACKGROUND: Severe kyphosis is a common condition in patients with advanced ankylosing spondylitis (AS). Although two-level osteotomy may serve as a potential alternative, it is often associated with increased blood loss and elevated surgical risks. To date, the optimal treatment for the challenging condition remains unclear. This study aims to introduce an effective strategy for the treatment of severe kyphosis secondary to AS, using one-level modified osteotomy combined with shoulders lifting correction method. METHODS: Seventy AS kyphosis who were treated with the strategy from 2012 to 2022, were reviewed retrospectively. All patients were followed up for a minimum duration of 2 years. Spinal and pelvic parameters were measured, including pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumber lordosis (LL), PI and LL mismatch (PI-LL), thoracic kyphosis, global kyphosis (GK), T1 pelvic angle (TPA), sagittal vertical axis (SVA), osteotomized vertebral angle (OVA), and chin-brow vertical angle (CBVA). Parameters of local osteotomized complex were measured and calculated, including the height of osteotomized complex and the length of spinal cord shortening. Clinical outcome was evaluated using Scoliosis Research Society-22 and Oswestry Disability Index scores. RESULTS: Seventy patients with average age of 39.8 years were followed-up for 29.3 months. Average operation time was 373.5 min, and average blood loss was 751.0 ml. Postoperatively, sagittal balance was successfully restored. GK decreased from 90.6° to 35.6°, LL decreased from 8.0° to -35.1°, TPA decreased from 56.8° to 27.8°, and SVA decreased from 24.4 cm to 8.7 cm (P < 0.05). A harmonious and matched spinopelvic alignment was achieved. PT decreased from 37.2° to 26.3°, PI-LL decreased from 54.1° to 10.2°, and SS increased from 9.2° to 19.7°(P < 0.05). Horizontal vision was obtained with postoperative CBVA of 8.8°. Average OVA correction was up to 47.3°, and the spinal cord was shortened by 24.3 mm, with a shortening rate of 36.0%. All patients demonstrated a favorable clinical outcome. No permanent nerve damage, screw loosening, rod breakage and main vascular injury were observed. One case required revision surgery due to screw cap loosening and delayed union. Solid bone fusion was achieved in all other patients. CONCLUSIONS: One-level modified osteotomy combined with shoulders lifting correction method is a safe and effective strategy for the treatment of severe AS kyphosis. This strategy offers a promising alternative for managing severe AS kyphosis, and may be particularly well-suited for individuals with concurrent osteoporosis. LEVEL OF EVIDENCE: Level IV, therapeutic study.

The Effect of Radiological Assessment of Volunteers for French Paratrooper Training: A Five-Year Retrospective Study.

INTRODUCTION: A systematic radiological examination is needed for military airborne troops in order to detect subclinical medical contraindications for airborne training. Many potential recruits are excluded because of scoliosis, kyphosis, or spondylolisthesis. This study aimed to determine whether complementary radiological assessment excludes too many recruits and whether medical standards might be lowered without increasing medical risk to appointees. METHODS: This retrospective, epidemiological, cross-sectional single-center study spanned 5 years at the French paratroopers' initial training center. We analyzed all medical files and full-spine X-ray results of all enlisted troops during this period. Secondary evaluation by an orthopedic surgeon enabled 23 enlisted personnel, deemed medically unacceptable because of X-ray findings, to be given waivers for airborne training. A follow-up review of their 23 files was conducted to determine whether static-line parachute jumps were hazardous to those who were initially declared medically unacceptable. RESULTS: Of the 3,993 full-spine X-rays, 67.5% (2,695) were described as having normal alignment and structure; 21.8% (871) had lateral spinal deviation; and 10.7% (427) had scoliosis. Sixty-six recruits (1.6%) were deemed unfit because of findings that did not meet the standard on the fullspine X-ray: 53 enlisted personnel had scoliosis greater than 15°, and 13 had spondylolisthesis (grade II or III). Of the 23 patients granted waivers, 82.3% with scoliosis (14) and all patients with kyphosis had not declared any back pain after 5 years. CONCLUSION: The findings, supported by a literature review of foreign military data, suggest that spondylolisthesis above grade I and low back pain are more significant than scoliosis and kyphosis for establishing airborne standards.

The Effect of Global Spinal Alignment on Cervical Degeneration in Patients with Degenerative Lumbar Scoliosis.

OBJECTIVE: To elucidate the effect of global spinal alignment on cervical degeneration in patients with degenerative lumbar scoliosis (DLS). METHODS: This study included 117 patients with DLS and 42 patients with lumbar spinal stenosis as a control group. Patients with DLS (study group) were categorized according to the Scoliosis Research Society-Schwab classification. Spinopelvic parameters were measured in cervical and full-length spine radiographs. Cervical degeneration was assessed using the cervical degeneration index (CDI) scoring system. RESULTS: There were significant differences in C2-C7 sagittal vertical axis, T1 slope, thoracic kyphosis, lumbar lordosis (LL), and pelvic tilt between DLS and control groups. Although the DLS and control groups did not differ significantly with regard to CDI scores, a striking difference was noted when sagittal spinopelvic modifiers were considered individually. Patients with a pelvic incidence (PI)-LL mismatch modifier grade of ++ had significantly higher CDI scores than patients with grade 0, and patients with a PI-LL or sagittal vertical axis modifier grade of ++ had significantly higher CDI scores than the control group. Disk narrowing scores were highest in patients with a PI-LL modifier grade of ++ followed by patients with a grade of +. Additionally, CDI scores were more associated with LL rather than cervical lordosis. CONCLUSIONS: Patients with DLS may be at greater risk of cervical spine degeneration, especially patients with a PI-LL or sagittal vertical axis modifier grade of ++. A surgical strategy for patients with DLS should be carefully selected considering the restoration of LL.

Using machine learning to automatically measure kyphotic and lordotic angle measurements on radiographs for children with adolescent idiopathic scoliosis.

Measuring the kyphotic angle (KA) and lordotic angle (LA) on lateral radiographs is important to truly diagnose children with adolescent idiopathic scoliosis. However, it is a time-consuming process to measure the KA because the endplate of the upper thoracic vertebra is normally difficult to identify. To save time and improve measurement accuracy, a machine learning algorithm was developed to automatically extract the KA and LA. The accuracy and reliability of the T1-T12 KA, T5-T12 KA, and L1-L5 LA were reported. A convolutional neural network was trained using 100 radiographs with data augmentation to segment the T1-L5 vertebrae. Sixty radiographs were used to test the method. Accuracy and reliability were reported using the percentage of measurements within clinical acceptance (≤9°), standard error of measurement (SEM), and inter-method intraclass correlation coefficient (ICC2,1). The automatic method detected 95 % (57/60), 100 %, and 100 % for T1-T12 KA, T5-T12 KA, and L1-L5 LA, respectively. The clinical acceptance rate, SEM, and ICC2,1 for T1-T12 KA, T5-T12 KA, and L1-L5 LA were (98 %, 0.80°, 0.91), (75 %, 4.08°, 0.60), and (97 %, 1.38°, 0.88), respectively. The automatic method measured quickly with an average of 4 ± 2 s per radiograph and illustrated how measurements were made on the image, allowing verifications by clinicians.

Spontaneous Resolution of Kyphoscoliosis Secondary to Guillain-Barre Syndrome: A Case Report.

CASE: Spinal deformity associated with Guillain-Barre syndrome (GBS) is not commonly reported. We present a 6-year-old girl who developed kyphoscoliosis after being diagnosed GBS. She had extensive motor deficits requiring 2 hospitalizations and treatment with IV immunoglobulin therapy. Five months after diagnosis, she presented to our clinic with a 15° coronal scoliosis and a 65° thoracic kyphosis. At 6-month follow-up, kyphosis progressed to 77° with no significant change in the coronal curve. At 1 year, sagittal alignment was within normal limits and the coronal curve had completely resolved. CONCLUSION: Spinal deformity in GBS can resolve spontaneously.

Segmental deformity markers offer novel indicators of deformity progression risk in deformity-matched adolescent idiopathic scoliosis patients.

PURPOSE: Identification of adolescent idiopathic scoliosis (AIS) patients with mild curvatures who pose significant risk of progressing to severe levels of curvatures is of paramount importance for clinical care. This study aimed to compare segmental deformity changes in AIS sub-cohorts that are dichotomised by progression status. METHODS: Thirty-six female participants with Lenke 1 AIS curves were investigated with sequential MRIs during growth. Scans were reformatted to measure orthogonal segmental parameters, including sagittal/coronal wedging angles and axial rotation angles. Participants were dichotomised by progression. Two-tailed, independent sample t-tests were used to compare sub-cohort multi-segmental and segmental deformity parameters. Measurements were compared at each scan number and variable rates of change were determined using actual time between measures. RESULTS: AIS progression status sub-cohorts were comparable at scan 1 for multi-segmental deformity parameters (e.g. major thoracic curve angle, rib hump, kyphosis) (P > 0.05). However, apical measures of coronal IVD wedging, axial IVD rotation and axial vertebral rotation were segmental parameters at scan 1 which were larger for participants whose AIS would later go on to clinically progress (all P < 0.05). Measures of segmental hypokyphosis were comparable between groups. As development was tracked at each subsequent scan, coronal and axial plane differences between groups increased in both magnitude and number of differences. CONCLUSION: Initial disparity and then subsequent increasing magnitude of change of axial rotation may indicate a higher propensity to clinically progress in the future. This knowledge hopes to provide useful management information for AIS care providers and prognostic education for patients alike. LEVEL OF EVIDENCE: II.

Bipolar hybrid posterior instrumentation tecnique for the correction of Scheuermann's kyphosis.

Scheuermann´s kyphosis (SK) is the most common cause of painful and progressive structural hyperkyphosis in adolescents. Surgical treatment should be considered in cases of refractory pain or progressive deformities. We present the clinical and radiological results obtained using a bipolar, hybrid posterior instrumentation tecnique. We analysed 12 males and 6 females, with mean age of 15.8 years. Minimum follow-up was 2 years. We used transverse process hooks at the cranial level and polyaxial screws for the remaining levels. We did not instrument the periapical segment. We used the sagittal stable vertebra (SSV) as the lower instrumented vertebra (LIV) in most cases, the "barely touched SSV" if the above disc space is lordotic. The mean preoperative kyphosis was 73.6º, mean postoperative kyphosis 44.7º, and mean correction of 28.9º (p = 0.0002). The mean reduction in lumbar lordosis (LL) was 8.9º (p = 0.0018). There were no significant differences in the spinopelvic parameters or sagittal balance. The mean number of instrumented levels was 8.9. Type II osteotomies were necessary in only three patients. Three patients had a cranial sagittal angle greater than 10°, all of them asymptomatic. Postoperatively, all patients had VAS scores less than 2 and SRS-22 scores greater than 4. Hybrid bipolar posterior instrumentation offers adequate curve correction, less operative time, implant density, bleeding, material protrusion and risk of spinal cord injury, leaving a large periapical bed for graft supply. We propose to measure the flexibility of the curve in MRI. In flexible curves (those that correct at least 20% in the supine decubitus position), wide facetectomies offer adequate correction of the deformity.

Risk predictive score and cord morphology classification for intraoperative neuromonitoring alerts in kyphosis surgery.

BACKGROUND: Intraoperative neuromonitoring (IONM) alert is one of the worrying events of kyphosis corrective surgery, which can result in a postoperative neurological deficit. To our knowledge, there is no risk prediction score to predict such events in patients undergoing kyphosis surgery. PURPOSE: To develop a new preoperative MRI-based cord morphology classification (CMC) and risk prediction score for predicting IONM alerts in patients with kyphotic deformity. STUDY DESIGN: Retrospective analysis of prospectively collected data. PATIENT SAMPLE: About 114 patients undergoing surgical correction for kyphotic deformity. OUTCOME MEASURES: Intraoperative neuromonitoring alerts and postoperative neurological status using AIS grading. METHODS: Kyphotic deformity patients undergoing posterior spinal fusion were retrospectively reviewed. Based on the morphology of the spinal cord and surrounding CSF in MRI, there are 5 types of cord. Type 1 (normal cord): circular cord with surrounding visible CSF between the cord and the apex, Type 2 (flattened cord): cord with <50% distortion at the apex with obliteration of the anterior CSF; Type 3 (deformed cord): cord with >50% distortion at the apex with complete obliteration of the surrounding CSF; Type 4 (stretched cord): the cord is stretched and atrophied over the apex of the curve. Type 5 (translated cord): horizontal translation of the cord at the apex with buckling collapse of the vertebral column. Preoperative radiographs were used to measure the preoperative sagittal cobbs angle, sagittal deformity angular ratio (S-DAR), sagittal vertical axis (SVA), apex of the curve, and type of kyphosis. Clinical data like the duration of symptoms, clinical signs of myelopathy, neurological status (AIS grade), grade of myelopathy using the mJOA score, and type of osteotomy were documented. Multivariate logistic regression was used to determine the risk factors for IONM alerts and the risk prediction score was developed which was validated with new cohort of 30 patients. RESULTS: A total of 114 patients met the inclusion criteria. IONM alerts were documented in 33 patients (28.9%), with full recovery of the signal in 25 patients and a postoperative deficit in 8 patients. Rate of IONM alerts was significantly higher in Type 5 (66%), followed by Type 4 (50%), Type 3 (21.1%), Type 2 (11.1%), and Type 1 (11.1%) (p-value<.001). Based on multiple logistic regression, 7 factors, namely preoperative neurological status, mJOA score≤6, presence of signs of myelopathy, apex of the curve above T5, preoperative sagittal cobbs, S-DAR, and MRI-based CMC, were identified as risk predictors. The value for the risk factors varies from 0 to 4, and the maximum total risk score was 13. The cut-off value of 6 had good sensitivity (84.9%) and specificity (77.8%) indicating a high risk for IONM alerts. The AUC of the predictive model was 0.92, indicating excellent discriminative ability. CONCLUSION: We developed and validated a risk predictive score that identifies patients at risk of IONM alerts during kyphosis surgery. Identification of such high-risk patients (risk score≥6) helps in proper evaluation and preoperative counselling and helps in providing a proper evidence-based reference for treatment strategies.

[Imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae].

Objective: To analyze the imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae in pediatric patients. Methods: The data of 13 patients with hemivertebrae locating in the lumbar spine symmetrically were retrospectively analyzed, and all the patients were treated in Beijing Children's Hospital from January 2015 to September 2021. The mean age of the patients was 6.2 (2.9, 9.3) years. There were 8 males and 5 females. The data of coronal/sagittal plane including segmental Cobb angle, cranial/caudal compensatory curve, thoracic kyphosis, thoracolumbar kyphosis, sacral obliquity, and lumbar lordosis were recorded through long cassette spinal radiographs. Associated anomalies and the relationship between hemivertebrae and posterior component were recorded through computerized tomography (CT) and magnetic resonance imaging (MRI). All the patients received surgery, and their pre-and postoperative imaging data were compared. Results: A total of 26 hemivertebraes were found, in which 80.8% (21/26) located below L2. Hemivertebraes in 10 patients were separated by a mean 1-2 normal vertebrae. Most hemivertebraes along with the corresponding posterior component were unison (21/26, 80.8%). The Cobb angles of cranial compensatory curve (13.9°±7.2°) was more serious than that of caudal compensatory curve (5.5°±5.0°)(P=0.04). The lumbar lordosis and thoracic kyphosis was 20.2°±15.0° and 18.7°±9.2°, respectively. Six patients complicated with sacral obliquity, while 7 patients complicated with thoracolumbar lordosis. Associated anomalies were found in 6 (46.2%) patients through CT and MRI. Eleven patients received one-or two-stage posterior hemivertebrae resection with short segmental fusion, and 2 patients received one-stage hemivertebrae resection with long segmental fusion. All the surgery were completed successfully without serious complications such as nerve injury, infection, and implant failure. The mean follow-up period was (42.4±10.2) months. At the last follow-up point, the correction rate of segmental Cobb angle and cranial compensatory curve was 83.3%±15.6% and 38.1%±10.4%, respectively, showing significant improvement (P<0.05). Although the caudal compensatory curve, sacral obliquity, and thoracic kyphosis improved after surgery, the data showed no significant difference compared to that before surgery. Thoracolumbar lordosis in all patients were corrected. Conclusions: Most hemivertebraes in such spinal deformity locate in lower lumbar region with a high incidence of anomalies. Individualized treatment based on patients' condition is essential for the complicated spinal deformity.

Cervical syringomyelia associated with cervical disc disease.

Background and purpose:

Syringomyelia is a neurological condition in which a longitudinal fluid-filled cavity is formed within the spinal cord. It usually occurs in the cervical region and is associated with Chiari malformation, infections, trauma, and tumors of the spinal cord. However, syringomyelia associated with cervical disc disease (SCD) is very rare and only a few cases have been reported so far. This case report presents the clinical and radiological findings of 13 cases of SCD to describe the properties of SCD and explore the nature of the relationship between syringomyelia and cervical disc disease.

SCD was diagnosed in 13 using MRI findings, including coexistence of syringomyelia and cervical disc disease, presence of narrowed cervical subarachnoid space secondary to the cervical disc herniation or cervical local kyphosis associated with cervical disc degeneration or herniation, and the cervical disc herniation or segmental kyphosis and syrinx should be located within the same levels. The MRI findings were used to grade the syrinx and determine whether the cervical disc herniation or local kyphosis was located at the proximal or distal end of the syrinx.

All patients had single-level disc herniation or kyphosis, the most common level being C5–6 (n = 6), followed by C6–7 (n = 4) and C4–5 (n = 3). Eight patients had a distal type (disc disease located in the proximal end of the syrinx) SCD while five had the proximal variety (cervical disc disease located in the distal end of the syrinx). The average length of the syrinx was two vertebral segments. Surgery was performed in five cases and some degree of syrinx resolution was observed in all of them.
Discussion – The main cause of syringomyelia is obstruction of cerebrospinal fluid (CSF) pathways; total obstruction could cause distal syrinx, whereas partial obstruction could cause proximal or distal syrinxes. Restoration of CSF pathways may result in some degree of resolution of syringomyelia. A causal association may exist between cervical disc disease and cervical syringomyelia but needs further exploration.

SCD is a mild form of syringomyelia with symptoms primarily arising due to disc herniation or local kyphosis. The surgical treatment of the cervical disc disease is sufficient and results in a syringomyelia resolution of some degree.

Endoscopic decompression of severe post-tuberculosis kyphosis related ossification of the ligamentum flavum: case report and literature review.

PURPOSE: Spinal tuberculosis, if not promptly treated, can lead to kyphotic deformity, causing persistent neurological abnormalities and discomfort. Spinal cord compression can occur due to ossification of the ligamentum flavum (OLF) at the apex of kyphosis. Traditional surgical interventions, including osteotomy and fixation, pose challenges and risks. We present a case of thoracic myelopathy in a patient with post-tuberculosis kyphosis, successfully treated with biportal endoscopic spinal surgery (BESS). METHOD: A 73-year-old female with a history of untreated kyphosis presented with walking difficulties and lower limb pain. Imaging revealed a kyphotic deformity of 120° and OLF-induced cord compression at T8-9. UBE was performed under spinal anesthesia. Using the BESS technique, OLF was successfully removed with minimal damage to the stabilizing structures. RESULTS: The patient exhibited neurological improvement after surgery, walking on the first day without gait instability. Follow-up at 1 year showed no kyphosis progression or recurrence of symptoms. BESS successfully resolved the cord compression lesion with minimal blood loss and damage. CONCLUSION: In spinal tuberculosis-related OLF, conventional open surgery poses challenges. BESS emerges as an excellent alternative, providing effective decompression with reduced instrumentation needs, minimal blood loss, and preservation of surrounding structures. Careful patient selection and surgical planning are crucial for optimal outcomes in endoscopic procedures.

Does Minimally Invasive Hemilaminectomy for Intradural Extramedullary Tumor Resection Prevent Postlaminectomy Kyphosis or Lordosis Loss?

BACKGROUND: Minimally invasive hemilaminectomy is a safe and effective alternative to open laminectomy for treating intradural extramedullary tumors. There are no reports of postoperative kyphosis after this approach. This study aims to determine whether performing minimally invasive spine surgery hemilaminectomy for intradural extramedullary tumors can prevent the development of postlaminectomy kyphosis (PLK) or lordosis loss. MATERIAL AND METHODS: Sixty-five patients with spinal intradural extramedullary tumors who underwent minimally invasive hemilaminectomy surgery and complete pre and postoperative radiologic imaging were included. The effect of the surgical approach on the spinal sagittal axis was assessed by comparing pre- versus postoperative segmental and local Cobb angles at different spinal levels, considering anatomical localization (cervical, thoracic, lumbar, and transition segments) and functional features (mobile, semi-rigid, and transition segments), as well as the extent of the surgical approach (1, 2, or 3 levels) and follow-up. RESULTS: None of the patients had an increase in thoracic kyphosis nor a loss of cervical or lumbar lordosis greater than or equal to 10° after undergoing the minimally invasive spine surgery hemilaminectomy approach. More than 5° of increase in kyphosis was detected on 7.4% and 11.1%, for the segmental and the local angles, respectively; meanwhile, for patients with loss of lordosis, this deviation was detected in 5.3%, for both angles. The occurrence of PLK was more common than that of lordosis loss, but mainly manifested in postoperative angle impairment of less than 5°. No significant differences were evidenced, considering the approach length. CONCLUSIONS: Hemilaminectomy represents a promising approach for preventing PLK and postlaminectomy lordosis loss following intradural extramedullary tumor resection.

Postoperative decrease in Hounsfield unit values at adjacent vertebrae after thoraco-pelvic fusion as a risk factor of proximal junctional kyphosis.

Proximal junctional kyphosis and failure is a common complication of adult spinal deformity surgery, with osteoporosis as a risk factor. This retrospective study investigated the influence of long thoracolumbar fusion with pelvic fixation on regional bone density of adjacent vertebrae (Hounsfield units on computed tomography) and evaluated the association between bone loss and the incidence of proximal junctional kyphosis and failure. Patients who underwent long thoracolumbar fusion (pelvis to T10 or above) or single-level posterior lumbar interbody fusion (control group) between 2016 and 2022 were recruited. Routine computed tomography preoperatively and within 1-2 weeks postoperatively was performed. Postoperative changes in Hounsfield unit values in the vertebrae at one and two levels above the uppermost instrumented vertebrae (UIV + 1 and UIV + 2) were evaluated. Overall, 127 patients were recruited: 45 long fusion (age, 73.9 ± 5.6 years) and 82 proximal junctional kyphosis and failure (age, 72.5 ± 9.3 years). Postoperative computed tomography was performed at a median [interquartile range] of 3.0 [1.0-7.0] and 4.0 [1.0-7.0] days, respectively. In both groups, Hounsfield unit values at UIV + 2 were significantly decreased postoperatively. In the long-fusion group, Hounsfield unit values at UIV + 1 and UIV + 2 were significantly lower in patients with proximal junctional kyphosis and failure (within 18 months postoperatively) than in those without proximal junctional kyphosis and failure. Proximal junctional kyphosis and failure and long thoraco-pelvic fusion negatively affect regional Hounsfield unit values at adjacent levels immediately after surgery. Patients with subsequent proximal junctional kyphosis and failure show greater postoperative bone loss at adjacent levels than those without.

Correlation of anterior chest wall anomalies and spinal deformities: a comprehensive descriptive study.

PURPOSE: To investigate the association and evaluate the characteristics between different types of anterior chest wall and spinal deformities. METHODS: A total of 548 patients with anterior chest wall deformities were included in this study. Clinical and radiological examinations were performed to determine spinal deformities. The type and severity of the spinal deformities were evaluated and their relationships with chest wall deformity subtypes were statistically analyzed. RESULTS: Spinal deformities were identified in 93 (16.97%) patients. The patients were subdivided into 71 (76.3%) male and 22 (23.7%) female patients. A spinal deformity was detected in 57 (13%) of 418 pectus excavatum (PE) patients, in 23 (19%) of 117 pectus carinatum (PC) patients, and in all patients with mixed pectus deformity (PE + PC), syndromic deformity and rib anomalies. In the PE group, scoliosis, and kyphosis were observed at 57.9 and 31.6%, respectively. In the PC group, these rates were 43.5 and 47.8%, respectively. Idiopathic scoliosis was observed in 42 (77.7%) and constituted the most common scoliosis subgroup. The main thoracic curvature was the most common curve pattern, which was observed in 15 (35.7%) patients with idiopathic scoliosis. CONCLUSIONS: Idiopathic scoliosis with main thoracic curvature is the most common deformity in patients with anterior chest wall deformity. Spinal deformities are more common in male patients with chest deformities. Kyphosis is found in a significant number of PE and PC patients. Patients with mixed PE and PC, rib anomalies, and syndromic disease are more likely to have spinal deformities.

Influence of slippage reduction and correction of lumbosacral kyphosis by single-level posterior lumbar interbody fusion on spinal alignment in patients with dysplastic spondylolisthesis.

PURPOSE: To investigate the influence of slippage reduction and correction of lumbosacral kyphosis by L5-S1 single-level posterior lumbar interbody fusion (PLIF) on spinal alignment and clinical outcomes including postoperative complications in patients with dysplastic spondylolisthesis (DS). METHODS: Twenty consecutive patients with symptomatic and severe DS who underwent L5-S1 single-level PLIF with a minimum of 2 years of follow-up after surgery were included. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores for low back and leg pain obtained on preoperative and postoperative examinations. Postoperative instrumentation failure and L5 radiculopathy were also evaluated. The preoperative and postoperative spinopelvic parameters were measured. RESULTS: The JOA score significantly improved from 21.5 ± 4.8 (preoperative) to 27.0 ± 2.5 (postoperative), with a mean recovery rate of 75.0% ± 30.4%. The VAS score for low back pain significantly improved from 44.5 ± 30.1 (preoperative) to 11.5 ± 15.9 (postoperative), and that for leg pain significantly improved from 31.0 ± 33.2 (preoperative) to 5.0 ± 10.2 (postoperative). The slip percentage (% slip) significantly improved from 59.6% ± 13.5% (preoperative) to 25.2% ± 15.0% (postoperative). The lumbosacral angle (LSA) significantly improved from 12.3° ± 9.5° (preoperative) to 1.0° ± 4.9° (postoperative). L5-S1 PLIF led to significant improvement of lumbar lordosis (from 52.0° ± 15.9° to 59.7° ± 8.0°) and pelvic incidence - lumbar lordosis mismatch (from 23.9° ± 20.6° to 13.3° ± 10.0°). Correction of lumbosacral kyphosis had a significant positive correlation with postoperative pelvic tilt (PT) (r = 0.50, P = 0.02), while postoperative % slip did not have a significant correlation with postoperative PT. CONCLUSIONS: L5-S1 PLIF for DS provided good clinical outcomes. Correction of lumbosacral kyphosis had a positive impact on regaining ideal spinopelvic balance and may be beneficial in the setting of treating DS.

Identification and impact of failure of pelvic compensation in patients with adult spinal deformity.

BACKGROUND CONTEXT: Previous research has identified a specific subtype known as failure of pelvic compensation (FPC) in patients with adult spinal deformity (ASD). However, the criteria for assessing FPC remain inconsistent, and its impacts on spinal sagittal alignment and health-related quality-of-life (HRQoL) scores remain unclear. PURPOSE: To propose a novel criterion for identifying FPC based on variations in spinopelvic alignment during the transition from the supine to upright position and to evaluate the effects of FPC on patients' spinal sagittal alignment and HRQoL scores. STUDY DESIGN/SETTING: Retrospective cross-sectional study. PATIENT SAMPLE: Patients with ASD from a monocenter database. OUTCOME MEASURES: Radiographic measures, including thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt, pelvic incidence (PI), and sagittal vertical axis (SVA), were measured on lateral whole-spine radiographs. LL and SS were also measured on reconstructed lumbar computed tomography images in the sagittal view taken in the supine position. The relative functional cross-sectional area (rFCSA) of paraspinal muscles was evaluated via lumbar magnetic resonance imaging. HRQoL measures, encompassing visual analog scale for back pain (VAS-BP), Oswestry Disability Index (ODI), and Scoliosis Research Society-22R (SRS-22R), were collected. METHODS: A total of 154 patients were enrolled. Based on the calculated minimum detectable change of SS, FPC was defined as the change in SS of less than 3.4° between supine and upright positions. Patients were divided into 3 groups: sagittal balance with pelvic compensation (SI-PC), sagittal imbalance with pelvic compensation (SI-PC), and sagittal imbalance with failure of pelvic compensation (SI-FPC). Radiographic parameters and HRQoL scores were compared among the groups. RESULTS: Thirty-six patients were categorized into the SB-PC group, 87 into the SI-PC group, and 31 into the SI-FPC group. Patients with low PI and small paraspinal muscles rFCSA were more prone to experiencing FPC accompanied by severe sagittal imbalance. The SI-FPC group exhibited less TK and a larger SS than the SI-PC group exhibited and had a similar SVA as that of the SI-PC group. Additionally, they displayed worse VAS-BP, ODI, SRS-function, and SRS-22 total scores than the SB-PC group displayed. CONCLUSIONS: In patients with ASD, an inherently low pelvic compensatory reserve and a high fatty infiltration in paraspinal muscles are pivotal factors contributing to FPC. Compared with SI-PC patients, SI-FPC patients demonstrate a thoracic-dominant compensatory pattern for sagittal malalignment. In addition, these patients experienced more severe pain and functional decline than the SB-PC patients experienced.

Cervical kyphosis after posterior cervical laminectomy with and without fusion.

BACKGROUND: Cervical posterior instrumentation and fusion is often performed to avoid post-laminectomy kyphosis. However, larger comparative analyses of cervical laminectomy with or without fusion are sparse. METHODS: A retrospective, two-center, comparative cohort study included patients after stand-alone dorsal laminectomy with (n = 91) or without (n = 46) additional fusion for degenerative cervical myelopathy with a median follow-up of 59 (interquartile range (IQR) 52) months. The primary outcome was the C2-7 Cobb angle and secondary outcomes were Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, revision rates, T1 slope and C2-7 sagittal vertical axis (C2-7 SVA) at final follow-up. Logistic regression analysis adjusted for potential confounders (i.e. age, operated levels, and follow-up). RESULTS: Preoperative C2-7 Cobb angle and T1 slope were higher in the laminectomy group, while the C2-7 SVA was similar. The decrease in C2-7 Cobb angle from pre- to postoperatively was more pronounced in the laminectomy group (- 6° (IQR 20) versus -1° (IQR 7), p = 0.002). When adjusting for confounders, the decrease in C2-7 Cobb angle remained higher in the laminectomy group (coefficient - 12 (95% confidence interval (CI) -18 to -5), p = 0.001). However, there were no adjusted differences for postoperative NDI (- 11 (- 23 to 2), p = 0.10), mJOA, revision rates, T1 slope and C2-7 SVA. CONCLUSION: Posterior cervical laminectomy without fusion is associated with mild loss of cervical lordosis of around 6° in the mid-term after approximately five years, however without any clinical relevance regarding NDI or mJOA in well-selected patients (particularly in shorter segment laminectomies of < 3 levels).