[Therapeutic effect of modified femoral neck osteotomy on the surgical treatment of ankylosing spondylitis with severe flexion deformity].

OBJECTIVE: To evaluate the efficacy of modified femoral neck osteotomy (mFNO) in the surgical treatment of patients with ankylosing spondylitis (AS) and severe spinal kyphosis combined with hip flexion contracture. METHODS: A retrospective analysis was conducted on 61 AS patients (103 hips) with spinal kyphosis and hip flexion contracture who underwent pedicle subtraction osteotomy (PSO) and total hip arthroplasty (THA) from January 1, 2019 to November 15, 2023. Data on mFNO operation time, blood loss, preoperative and postoperative values of the angle of the trunk and lower limb (ATL), hip passive range of motion (ROM), visual analogue scale (VAS), and incidence of in-hospital complications were recorded. Statistical analysis was performed using paired-samples t test. P < 0.05 was considered statistically significant. RESULTS: The study ultimately included 10 cases, 9 males and 1 female, with an average age of (41.30±9.03) years. These patients underwent surgery for a total of 52 times, including 19 hips both receiving mFNO and THA, and 14 times PSO. The average operation time for nine bilateral mFNO was (133.11±34.81) min, with blood loss of (433.33±187.10) mL. A unilateral mFNO took 60 min with 200 mL of blood loss. The preoperative ATL of 19 hips was 40.37°±13.66°, and the postoperative ATL value was 88.47°±12.46° (P < 0.05). The preoperative VAS score was 0, while the postoperative VAS score was 5.95±1.51 (P < 0.05). The preoperative hip extension ROM was 37.37°±18.13°, while the postoperative hip extension ROM was -4.95°±21.24° (P < 0.05). Hip flexion ROM improved from 37.37°±18.13° to 50.79°±20.36° after FNO (P < 0.05). There were three cases of in-hospital complications (3/52, 5.67%): One case of postoperative atelectasis following PSO (1/52, 1.92%), one greater trochanter fracture identified during THA (1/52, 1.92%), and one early dislocation post-THA (1/52, 1.92%). CONCLUSION: mFNO significantly improves the ATL in AS patients with severe spinal kyphosis combined with hip flexion contracture, facilitating PSO and THA surgeries.

Factors associated with loss of vertebral height and kyphosis correction after intermediate screws in short segment pedicular fixation for type-A fractures of the thoracolumbar spine: A retrospective study.

In this article, we attempted to identify risk factors affecting the loss of vertebral height and kyphosis correction on type A thoracolumbar fractures. Patients with type A thoracolumbar fractures who underwent short segments with intermediate screws at the fracture level management between 2017 and 2022 were included in this study. Clinical factors including patients' demographic characteristics (age, sex), history (smoking, hypertension and/or diabetes), value of height/kyphosis correction, the thoracolumbar injury classification and severity score (TLICS), the load sharing classification (LSC) scores and bone mineral density were collected. Correlation coefficient, simple linear regression analysis and multivariate regression analysis were performed to identify the clinical factors associated with the loss of vertebral height/kyphosis correction. Finally, 166 patients were included in this study. The mean height and kyphosis correction were 21.8% ±â€…7.5% and 9.9°â€…±â€…3.8°, respectively, the values of the loss were 6.5% ±â€…4.0% and 3.9°â€…±â€…1.9°, respectively. Simple linear regression analysis and multivariate regression analysis showed that age, value of height correction, LSC scores and bone mineral density were significantly associated with the loss of vertebral height and kyphosis correction (P < .01) We could draw the conclusion that patients with older age, lower bone mineral density, higher LSC scores and diabetes are at higher risk of vertebral height and kyphosis correction loss increase. For these patients, appropriate clinical measures such as long segment fixation, control of blood glucose, and increase of bone density must be taken to reduce the loss of correction.

[Application of ultrasonic bone scalpel system for laminectomy and posterior longitudinal ligament ossification block release combined with dekyphosis orthopedic surgery in treatment of multisegmental thoracic ossification of posterior longitudinal ligament].

Objective: To explore the safety and effectiveness of multisegmental thoracic ossification of posterior longitudinal ligament (T-OPLL) treated by laminectomy, posterior longitudinal ligament ossification block release combined with dekyphosis orthopedic surgery using ultrasonic bone scalpel system. Methods: The clinical data of 8 patients with multisegmental T-OPLL treated with laminectomy, posterior longitudinal ligament ossification block release combined with dekyphosis orthopedic surgery using ultrasonic bone scalpel system between January 2020 and April 2023 was retrospectively analyzed. There were 3 males and 5 females; the age ranged from 41 to 67 years, with a mean of 57.1 years. The disease duration ranged from 3 to 74 months, with a mean of 33.4 months. Symptoms were progressive numbness and weakness of both lower limbs, unsteady walking, chest and back pain in 3 cases, and urinary and bowel dysfunction in 5 cases; 7 cases showed increased muscle strength of the lower limbs, hyperreflexia of the tendons, and a positive Babinski sign, and 1 case showed decreased muscle strength of the lower limbs, decreased skin sensation, decreased knee and Achilles tendon reflexes, and a negative pathologic sign. Multisegmental posterior longitudinal ligament ossification of thoracic spine was found in 8 cases, with 4-8 segments of ossification, and in 5 cases with multisegmental ossification of the ligamentum flavum. The preoperative Japanese Orthopaedic Association (JOA) thoracic spinal function score was 4.3±0.9, the visual analogue scale (VAS) score was 6.9±1.0, and the the kyphotic Cobb angle of the stenosis segment was (34.62±10.76)°. The operation time, intraoperative blood loss, and complications were recorded. VAS score was used to evaluate the back pain, JOA score was used to evaluate the thoracic spinal cord function and the JOA improvement rate was calculated, and the kyphotic Cobb angle of the stenosis segment was measured and the Cobb angle improvement rate was calculated. Results: The operation time ranged from 210 to 340 minutes, with a mean of 271.62 minutes; intraoperative blood loss ranged from 900 to 2 100 mL, with a mean of 1 458.75 mL; the number of resected vertebral plates ranged from 4 to 8, with a mean of 6.1; dural tears and cerebrospinal fluid leakage occurred in 3 cases, and the incisions healed by first intention. All 8 cases were followed up 12-26 months, with a mean of 18.3 months. There was no complication such as loosening of internal fixator, breakage of screws and rods, and no significant progress of ossification. At last follow-up, the VAS score was 1.4±0.7, the JOA thoracic spinal function score was 9.8±0.7, and the the kyphotic Cobb angle of the stenosis segment was (22.12±8.28)°, all of which significantly improved when compared with preoperative ones ( t=11.887, P<0.001; t=13.015, P<0.001; t=7.395, P<0.001). The JOA improvement rate was 81.06%±10.93%, of which 5 cases were rated as excellent and 3 cases as good; the Cobb angle improvement rate was 36.51%±14.20%. Conclusion: Laminectomy, posterior longitudinal ligament ossification block release combined with dekyphosis orthopedic surgery using ultrasonic bone scalpel system is a safe, effective, and simple method for the treatment of multisegmental T-OPLL, which is a feasible option.

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.

Excessive posterior placement of upper instrumented vertebra relative to lower instrumented vertebra as a predictor of proximal junction kyphosis after selective spinal fusion for adolescent idiopathic scoliosis Lenke type 5C curves.

PURPOSE: We defined sagittal S-line tilt (SSLT) as the tilt of the line connecting the upper instrumented vertebra and the lower instrumented vertebra. This study aimed to: (1) examine the correlation between SSLT and proximal junctional angle (PJA) change values, and (2) determine the cut-off value of SSLT with respect to proximal junctional kyphosis (PJK) occurrence. METHODS: Eighty-six consecutive patients (81 female and 5 male; mean age: 15.8 years) with Lenke 5C AIS who underwent posterior selective spinal fusion. Pearson's correlation coefficients were used to examine the relationship between preoperative SSLT and changes in PJA from preoperative to 2 years postoperative. The impact of SSLT on PJK at 2 years after surgery was assessed using a receiver operating characteristic (ROC) curve. RESULTS: We observed a moderate positive correlation between preoperative SSLT and change in PJA (R = 0.541, P < 0.001). We identified 18 patients (21%) with PJK at 2 years postoperative. Mean preoperative SSLT in the PJK group and the non-PJK group differed significantly at 23.3 ± 4.1° and 16.1 ± 5.0°, respectively (P < 0.001). The cut-off value of preoperative SSLT for PJK at 2 years postoperative was 18° in ROC curve analysis, with a sensitivity of 94%, specificity of 68%, and area under the ROC curve of 0.868. CONCLUSION: In selective lumbar fusion for AIS Lenke type 5C curves, preoperative SSLT was significantly correlated with PJA change from preoperative to 2 years postoperative. SSLT was a predictor of PJK occurrence, with a cut-off value of 18°.

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.

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.

[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.

Analysis of Spinal-Pelvic Sagittal Plane Parameters in Patients with Lumbar Vertebral Posterior Ring Apophysis Separation.

OBJECTIVE: To investigate the characteristics of the spinal-pelvic sagittal sequence in patients with lumbar vertebral posterior ring apophysis separation (PRAS). METHODS: A retrospective analysis was conducted on 119 hospitalized patients with PRAS, and 119 adults without symptoms of low back and leg pain were selected as the control. General data and spinal-pelvic sagittal parameters were collected and analyzed. RESULTS: Compared to the control group, the pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and thoracic kyphosis of the PRAS group were significantly lower, while the pelvic tilt (PT), sagittal vertical axis, and PI minus LL were significantly higher. There was no significant difference in thoracolumbar kyphosis between the 2 groups. In patients with PRAS, the LL value of lumbar curvature was moderately correlated with thoracic kyphosis and SS, while PI, PT, and SS were pairwise correlated, indicating that the change in one parameter is often accompanied by simultaneous changes in other parameters if PRAS happens. The correlation between different parameters could provide guidance for the diagnosis of PRAS. In terms of LL type, the PRAS group was mainly of Roussouly type I, while the control group was mainly of type II, and the difference in the composition ratio was statistically significant. CONCLUSIONS: As reflected by the spinal-pelvic sagittal parameters, the patients with PRAS exhibited reduced thoracic and lumbar curvature, posterior PT, and fewer vertebral bodies involved in LL. These morphological characteristics indicate the changes of the mechanical structure of the spine.

Posterior-Only T11 Vertebral Column Resection for Pediatric Congenital Kyphosis Surgical Correction.

Background: Congenital kyphosis is a spinal deformity that arises from the inadequate anterior development or segmentation of the vertebrae in the sagittal plane during the initial embryonic stage. Consequently, this condition triggers atypical spinal growth, leading to the manifestation of deformity. Concurrently, other congenital abnormalities like renal or cardiac defects within the gastrointestinal tract may co-occur with spinal deformities due to their shared formation timeline. In light of the specific characteristics of the deformity, the age range of the patient, deformity sizes, and neurological conditions, surgical intervention emerges as the optimal course of action for such cases. The selection of the appropriate surgical approach is contingent upon the specific characteristics of the anomaly. Case Presentation: This investigation illustrates the utilization of a surgical posterior-only strategy for correcting pediatric congenital kyphoscoliosis through the implementation of a vertebral column resection method along with spine reconstruction employing a mesh cage. The individual in question, a 16-year-old female, exhibited symptoms such as a progressive rib hump, shoulder asymmetry, and back discomfort. Non-invasive interventions like bracing proved ineffective, leading to the progression of the spinal curvature. After the surgical procedure, diagnostic imaging displayed a marked enhancement across all three spatial dimensions. After a postoperative physical assessment, it was noted that the patient experienced significant enhancements in shoulder alignment and rib hump prominence, with no discernible neurological or other adverse effects. Conclusions: Surgical intervention is considered the optimal approach for addressing such congenital anomalies. Typically, timely surgical intervention leads to favorable results and has the potential to halt the advancement of deformity and curvature enlargement.

Proximal junctional kyphosis after adult spinal deformity operated patients with long fusion to the pelvis. Does the type of proximal anchor matter?

PURPOSE: To assess, in a large population of Adult Spinal Deformity (ASD) patients, the true interest of varying the upper anchors as a protective measure against Proximal Junctional Kyphosis (PJK), by analyzing and comparing 2 groups of patients defined according to their proximal construct. Another objective of the study is to look for any other factors, radiological or clinical, that would affect the occurrence of the proximal failure. METHODS: Retrospective review of a prospective ASD database collected from 5 centers. Inclusion criteria were age of at least 18 years, presence of a spinal deformity with instrumentation from T12 or above to the pelvis, with minimum 2 years of follow-up. Demographic data, spinopelvic parameters, functional outcomes and complications were collected. Multiple logistic regression analysis was performed to identify the risk factors that would affect the occurrence of PJK. RESULTS: 254 patients were included. 166 in the group "screws proximally" (SP) and 88 in the group "hooks proximally" (HP). There was no difference between both groups for PJK (p = 0.967). The occurrence of PJK was rather associated with greater age and BMI, higher preoperative kyphosis, worst preoperative SRS22 and SF36 scores, greater postoperative Sagittal Vertical Axis (SVA), coronal malalignment and kyphosis. CONCLUSION: The use of proximal hooks was not effective to prevent PJK after ASD surgery, when compared to proximal screws. Worse preoperative functional outcomes and worse postoperative sagittal and also coronal malalignment were the main drivers for the occurrence of PJK regardless the type of proximal implant.

Importance of the lumbar paraspinal muscles on the maintenance of global sagittal alignment after lumbar pedicle subtraction osteotomy.

OBJECTIVE: There are limited data about the influence of the lumbar paraspinal muscles on the maintenance of sagittal alignment after pedicle subtraction osteotomy (PSO) and the risk factors for sagittal realignment failure. The authors aimed to investigate the influence of preoperative lumbar paraspinal muscle quality on the postoperative maintenance of sagittal alignment after lumbar PSO. METHODS: Patients who underwent lumbar PSO with preoperative lumbar MRI and pre- and postoperative whole-spine radiography in the standing position were included. Spinopelvic measurements included pelvic incidence, sacral slope, pelvic tilt, L1-S1 lordosis, T4-12 thoracic kyphosis, spinosacral angle, C7-S1 sagittal vertical axis (SVA), T1 pelvic angle, and mismatch between pelvic incidence and L1-S1 lordosis. Validated custom software was used to calculate the percent fat infiltration (FI) of the psoas major, as well as the erector spinae and multifidus (MF). A multivariable linear mixed model was applied to further examine the association between MF FI and the postoperative progression of SVA over time, accounting for repeated measures over time that were adjusted for age, sex, BMI, and length of follow-up. RESULTS: Seventy-seven patients were recruited. The authors' results demonstrated significant correlations between MF FI and the maintenance of corrected sagittal alignment after PSO. After adjustment for the aforementioned parameters, the model showed that the MF FI was significantly associated with the postoperative progression of positive SVA over time. A 1% increase from the preoperatively assessed total MF FI was correlated with an increase of 0.92 mm in SVA postoperatively (95% CI 0.42-1.41, p < 0.0001). CONCLUSIONS: This study included a large patient cohort with midterm follow-up after PSO and emphasized the importance of the lumbar paraspinal muscles in the maintenance of sagittal alignment correction. Surgeons should assess the quality of the MF preoperatively in patients undergoing PSO to identify patients with severe FI, as they may be at higher risk for sagittal decompensation.

Determining the vertebra for pedicle subtraction osteotomy in surgical correction for ankylosing spondylitis with thoracolumbar kyphosis.

OBJECTIVE: This study aimed to provide a method for determining the apical vertebra for pedicle subtraction osteotomy (PSO) in corrective surgery for patients with ankylosing spondylitis (AS) with thoracolumbar kyphosis (TLK). METHODS: The medical records of AS patients with TLK who underwent PSO between May 2009 and August 2022 were retrospectively reviewed, and 235 patients were included in the study. Using the proposed method, choosing the vertebra based on Kim's apex (KA), which is defined as the farthest vertebra from a line drawn from the center of the T10 vertebral body to the midpoint of the S1 upper endplate, the authors analyzed 229 patients with apices at T12, L1, or L2 (excluding L3 because of the small sample size, n = 6). They divided all patients into two groups. Group A (n = 144) underwent PSO at the KA vertebra, while group B (n = 85) underwent PSO at a different level. Demographic and radiological data, including sagittal spinopelvic parameters of the entire spine, were collected. An additional analysis was performed on patients with the same KA vertebra. RESULTS: The vertebra distributions of patients based on KA were T12 (28 [12.2%]), L1 (119 [52.0%]), and L2 (82 [35.8%]). The corrections of sagittal vertical axis (SVA; 101.0 ± 48.5 mm vs 82.0 ± 53.8 mm, p = 0.010), global kyphosis (GK; 31.6° ± 10.0° vs 26.4° ± 10.5°, p = 0.005), and TLK (29.4° ± 10.2° vs 24.2° ± 12.9°, p = 0.012) in group A were significantly greater than those in group B, and there was no difference in the corrections of thoracic kyphosis (TK), lumbar lordosis, and pelvic incidence between the two groups. On further analysis, group A showed greater correction in TK (26.2° ± 13.7° vs 0.1° ± 8.1°, p = 0.013) for patients with T12 as the KA; greater improvements in SVA (101.5 ± 44.2 mm vs 73.4 ± 48.7 mm, p = 0.020), GK (30.6° ± 11.0° vs 25.0° ± 10.4°, p = 0.046), and TLK (32.6° ± 7.8° vs 26.7° ± 9.9°, p = 0.012) for those with L1 as the KA; and significant correction in TLK (30.0° ± 6.3° vs 4.3° ± 19.5°, p = 0.008) for patients with L2 as the KA, compared with group B. CONCLUSIONS: PSO at the apical vertebra provides a greater degree of correction of sagittal imbalance. The proposed method, selecting the vertebra based on KA, is easily reproducible for determining the apex level in AS patients with TLK.

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).

Modified pedicle subtraction osteotomy for osteoporotic vertebral compression fractures: a retrospective study of 104 patients.

BACKGROUND: Osteoporotic vertebral compression fractures (OVCF) caused by osteoporosis is a common clinical fracture type. There are many surgical treatment options for OVCF, but there is a lack of comparison among different options. Therefore, we counted a total of 104 cases of OVCF operations with different surgical plans, followed up the patients, and compared the surgical outcome indications before, after and during the follow-up. METHOD: 104 patients who underwent posterior osteotomy (Modified PSO, SPO, PSO, VCR) and kyphosis correction surgery at our hospital between April 2006 and August 2021 with a minimum follow-up period of 24 months were included. All cases were injuries induced by a fall incurred while standing or lifting heavy objects without high-energy trauma. The mean CT value was 71 HU, which was below 110 HU, indicating severe osteoporosis. The indications for surgery included gait disturbance due to severe pain with pseudarthrosis, increased kyphotic angle, and progressive neurological symptoms. Pre- and postoperative CL, TLK, TK, PrTK, TKmax, GK, LL, PI, SS, PT, SVA, TPA, were investigated radiologically. Additionally, We evaluated estimated blood loss, surgical time and perioperative symptom. RESULT: The results show, after operation, TLK (37.32 ± 10.61° vs. 11.01 ± 8.06°, P < 0.001), TK (35.42 ± 17.64° vs. 25.62 ± 12.24°, P < 0.001), TKmax (49.71 ± 16.32° vs. 24.12 ± 13.34°, P < 0.001), SVA (44.91 ± 48.67 vs. 23.52 ± 30.21, P = 0.013), CL (20.23 ± 13.21° vs. 11.45 ± 9.85°, P = 0.024) and TPA (27.44 ± 12.76° vs. 13.91 ± 9.24°, P = 0.009) were improved significantly in modified Pedicle subtraction osteotomy (mPSO) after operation. During follow-up, TLK (37.32 ± 10.61° vs. 13.88 ± 10.02°, P < 0.001) and TKmax (49.71 ± 16.32° vs. 24.12 ± 13.34°, P < 0.001) were improved significantly in Modified PSO group. In additon, estimated blood loss (790.0 ± 552.2 ml vs. 987.0 ± 638.5 ml, P = 0.038), time of operation (244.1 ± 63.0 min vs. 292.4 ± 87.6 min, P = 0.025) were favorable in Modified PSO group compared to control group. CONCLUSION: To conclude, mPSO could acquire a favorable degree of kyphosis correction as well as fewer follow-up complications. Compared with other surgical methods, it also has the advantages of less surgical trauma and shorter operation time. It can be an effective solution for the treatment of OVCF.

Coronal deformity in ankylosing spondylitis with concomitant thoracolumbar kyphosis: patterns, manifestations and surgical strategies.

PURPOSE: To evaluate different patterns of coronal deformity secondary to ankylosing spondylitis (AS), to propose relevant treatment strategies, and to assess efficacy of asymmetrical pedicle subtraction osteotomy (APSO). METHODS: Coronal deformity was defined as coronal Cobb angle over 20º or coronal balance distance (CBD) more than 3 cm. 65 consecutive AS patients with concomitant coronal and sagittal deformity who underwent PSO were included. The average follow-up time was 40.4 months. Radiographic evaluation included coronal Cobb angle and CBD. Furthermore, sagittal parameters were used to assess magnitude and maintenance of kyphosis correction. RESULTS: Based on curve characteristics, coronal deformity caused by AS included four different radiologic patterns: Pattern I: lumbar scoliosis; Pattern II: C-shaped thoracolumbar curve; Pattern III: trunk shift without major curve; Pattern IV: proximal thoracic scoliosis. APSO was performed for patients in Pattern I to III while conventional PSO was applied for patients in Pattern IV. Significant improvement in all the sagittal parameters were noted in 65 patients without obvious correction loss at the last follow-up. Besides, significant and sustained correction of coronal mal-alignment was identified in 59 APSO-treated patients. Rod fracture occurred in four cases and revision surgery was performed for one case. CONCLUSION: According to radiologic manifestations, coronal deformity caused by AS could be categorized into four patterns. APSO proved to be a feasible and effective procedure for correction of Pattern I to III patients. Coronal deformity pattern, apex location, sagittal profile of lumbar spine and preoperative hip function should be considered for osteotomy level selection in APSO.

Can We Rely on Prophylactic Two-Level Vertebral Cement Augmentation in Long-Segment Adult Spinal Deformity Surgery to Reduce the Incidence of Proximal Junctional Complications?

Background and Objectives: Proximal junctional kyphosis (PJK) and failure (PJF), the most prevalent complications following long-segment thoracolumbar fusions for adult spinal deformity (ASD), remain lacking in defined preventive measures. We studied whether one of the previously reported strategies with successful results-a prophylactic augmentation of the uppermost instrumented vertebra (UIV) and supra-adjacent vertebra to the UIV (UIV + 1) with polymethylmethacrylate (PMMA)-could also serve as a preventive measure of PJK/PJF in minimally invasive surgery (MIS). Materials and Methods: The study included 29 ASD patients who underwent a combination of minimally invasive lateral lumbar interbody fusion (MIS-LLIF) at L1-2 through L4-5, all-pedicle-screw instrumentation from the lower thoracic spine to the sacrum, S2-alar-iliac fixation, and two-level balloon-assisted PMMA vertebroplasty at the UIV and UIV + 1. Results: With a minimum 3-year follow-up, non-PJK/PJF group accounted for fifteen patients (52%), PJK for eight patients (28%), and PJF requiring surgical revision for six patients (21%). We had a total of seven patients with proximal junctional fracture, even though no patients showed implant/bone interface failure with screw pullout, probably through the effect of PMMA. In contrast to the PJK cohort, six PJF patients all had varying degrees of neurologic deficits from modified Frankel grade C to D3, which recovered to grades D3 and to grade D2 in three patients each, after a revision operation of proximal extension of instrumented fusion with or without neural decompression. None of the possible demographic and radiologic risk factors showed statistical differences between the non-PJK/PJF, PJK, and PJF groups. Conclusions: Compared with the traditional open surgical approach used in the previous studies with a positive result for the prophylactic two-level cement augmentation, the MIS procedures with substantial benefits to patients in terms of less access-related morbidity and less blood loss also provide a greater segmental stability, which, however, may have a negative effect on the development of PJK/PJF.

Independent Risk Factors of Proximal Junctional Kyphosis with Vertebral Fracture After Spinal Long Fusion: Survivorship Analysis of Adult Spinal Deformity Surgery Patients.

OBJECTIVE: This study aimed to identify risk factors for postoperative proximal junctional kyphosis (PJK) with vertebral fracture in adult spinal deformity (ASD) patients. We performed a survival analysis considering various factors, including osteoporosis. METHODS: This single-center retrospective study included 101 ASD patients (mean age: 67.2 years, mean follow-up: 8.1 years). We included patients aged ≥50 years with abnormal radiographic variables undergoing corrective long spinal fusion. The main outcome measure was PJK with vertebral fracture, analyzed based on patient data, radiographic measurements, sagittal parameters, bone mineral density, and osteoporosis medication. RESULTS: PJK occurred in 37.6% of patients, with vertebral fracture type 2 accounting for 65% of these cases. Kaplan-Meier analysis indicated a median PJK-free survival time of 60.7 months. Existing vertebral fracture (grade 1 or higher or grade 2 or higher) was a significant risk factor for PJK with vertebral fracture, with hazard ratios of 4.58 and 5.61, respectively. The onset time of PJK with vertebral fracture was 1.5 months postoperatively, with 44% of these cases occurring within 1 month and 64% within 2 months. CONCLUSIONS: PJK with vertebral fracture affected 25% of ASD patients, emphasizing the importance of osteoporosis evaluation. Existing vertebral fracture emerged as a significant independent risk factor, surpassing bone mineral density. This study provides valuable insights for spine surgeons, highlighting the need to provide osteoporosis treatment and emphasize potential postoperative complications during discussions with patients.

Is It Meaningful and Necessary to Avoid the Seventh Cervical Vertebra in Long Level Cervical Fusion?

AIM: To compare the clinical and radiological results of patients who underwent multilevel posterior cervical fusion (PCF) with different end levels (C6 or C7). MATERIAL AND METHODS: We collected radiographs and clinical results of all subjects who underwent 3 level or more PCF for degenerative disease from May 2012 to December 2020. Based on the location of the end of fusion during surgery, patients were divided into C6 (group 1) and C7 patients (group 2). The clinical and radiological results of both groups were compared over two years. RESULTS: A total of 52 patients met the inclusion criteria of this study (21 in group 1 and 31 in group 2). The clinical results demonstrated a statistically significant difference with respect to a lower neck visual analog scale score in group 1 than in group 2 at the last follow-up (p=0.03). With regard to the radiological results, the C2-C7 sagittal vertical axis showed significantly greater values in group 2 than in group 1 at the final follow-up (p=0.02). For thoracic kyphosis (TK), group 2 had lower TK values than group 1 (p=0.03), and the T9 spinopelvic inclination was significantly greater in group 2 than in group 1 (p=0.01). CONCLUSION: In this study, aggravation of cervical kyphosis and neck pain was observed when C7 was included in multilevel PCF surgery. The inclusion of C7 also affected the thoracolumbar parameters and global spine alignment.

Predictive role of FRAX© for postoperative proximal junctional kyphosis with vertebral fracture after adult spinal deformity surgery.

PURPOSE: To identify risk factors, including FRAX (a tool for assessing osteoporosis) scores, for development of proximal junctional kyphosis (PJK), defined as Type 2 in the Yagi-Boachie classification (bone failure), with vertebral fracture (VF) after surgery for symptomatic adult spinal deformity. METHODS: This was a retrospective, single institution study of 127 adults who had undergone corrective long spinal fusion of six or more spinal segments for spinal deformity and been followed up for at least 2 years. The main outcome was postoperative development of PJK with VF. Possible predictors of this outcome studied included age at surgery, BMI, selected radiographic measurements, bone mineral density, and 10-year probability of major osteoporotic fracture (MOF) as determined by FRAX. We also analyzed use of medications for osteoporosis. Associations between the selected variables and PJK with VF were assessed by the Mann-Whitney, Fishers exact, and Wilcoxon signed-rank tests, and Kaplan-Meier analysis, as indicated. RESULTS: Forty patients (31.5%) developed PJK with VF postoperatively,73% of them within 6 months of surgery. Statistical analysis of the selected variables found that only a preoperative estimate by FRAX of a > 15% risk of MOF within 10 years, pelvic tilt > 30° at first standing postoperatively and lower instrumented level (fusion terminating at the pelvis) were significantly associated with development of PJK with VF. CONCLUSION: Preoperative assessment of severity of osteoporosis using FRAX provides an accurate estimate of risk of postoperative PJK with VF after surgery for adult spinal deformity.