Risk factors for proximal junctional kyphosis after posterior long-segment internal fixation for chronic symptomatic osteoporotic thoracolumbar fractures with kyphosis.

BACKGROUND: This study aimed to analyze the risk factors for proximal junctional kyphosis (PJK) for patients with chronic symptomatic osteoporotic thoracolumbar fractures (CSOTLF) and kyphosis who underwent long-segment internal fixation. METHODS: We retrospectively reviewed the records of patients with CSOTLF complicated with kyphosis who underwent posterior multilevel internal fixation in our hospital between January 2013 and January 2020. The patients' age, sex, body mass index (BMI), bone mineral density (BMD), smoking status, cause of injury, comorbidities, injury segments, and American Spinal Injury Association (ASIA) grading non-surgical data; posterior ligament complex (PLC) injury, upper and lower instrumented vertebral position (UIV and LIV, respectively), number of fixed segments surgical data, proximal junctional angle (PJA), sagittal vertebral axis (SVA), pelvic incidence (PI), lumbar lordosis (LL), pelvic incidence-lumbar lordosis mismatch (PI-LL), pelvic tilt (PT), and sacral slope (SS) surgical indicators were collected. Patients were divided into postoperative PJK and non-PJK groups. RESULTS: This study included 90 patients; among them, 30 (31.58%) developed PJK postoperatively. All patients were followed up for > 24 months (mean 32.5 months). Univariate analysis showed significant differences in age, BMI, BMD, PLC injury, UIV, and LIV fixation position, number of fixation stages, and preoperative PJA, SVA, PI-LL, and SS between the two groups (P < 0.05). Additionally, no significant differences were observed in sex, smoking, cause of injury, complications, injury segment ASIA grade, and preoperative PT between the two groups (P > 0.05). Multifactorial logistic regression analysis showed that age > 70 years (OR = 32.279, P < 0.05), BMI > 28 kg/m2 (OR = 7.876, P < 0.05), BMD T value < - 3.5 SD (OR = 20.836, P < 0.05), PLC injury (OR = 13.981, P < 0.05), and preoperative PI-LL > 20° (OR = 13.301, P < 0.05) were risk factors for PJK after posterior long-segment internal fixation in elderly patients with CSOTLF complicated with kyphosis. CONCLUSION: CSOTLF patients undergoing posterior long segment internal fixation are prone to PJK, and age > 70 years, BMI > 28 kg/m2, BMD T value < - 3.5 SD, preoperative PI-LL > 20° and PLC injury may increase their risk.

When is the circumferential stabilization necessary for subaxial cervical fracture dislocations? The posterior ligament-bone injury classification and severity score: a novel treatment algorithm.

OBJECTIVE: To propose a novel classification and scoring system called the posterior ligament-bone injury classification and severity score (PLICS) that offers a quantitative score to guide the need for posterior stabilization in addition to anterior reconstruction for subaxial cervical fracture dislocations (SCFDs). METHODS: A total of 456 patients with SCFDs were prospectively included. Patients with PLICS ≥ 7 together with extremely unstable lateral mass fracture (EULMF) were classified as high-risk group, and the other patients were classified as low-risk group. For patients in the low-risk group, anterior-only reconstruction was performed; for patients in the high-risk group, additional posterior lateral mass fixation and fusion was performed after anterior reconstruction. Clinical outcome evaluation included using the visual analogue score (VAS), the Neck Disability Index (NDI), and the American Spinal Injury Association (ASIA) impairment scale. The change in the local sagittal alignment kyphosis Cobb angle was also recorded. RESULTS: A total of 370 patients (81.1%) completed the minimal 12-month follow-ups, including 321 patients of low-risk group and 49 patients of high-risk group. Compared with the average VAS score preoperatively, the score at 12-month follow-up was significantly improved (from 6.1 + 0.3 to 1.1 + 0.2 in the low-risk group, P < 0.001; from 6.4 + 0.2 to 1.4 + 0.2 in the high-risk group, P < 0.001). The average NDI score at the 12-month follow-up was statistically low in the low-risk group (8.8 + 2.5 vs 13.8 + 3.4, P = 0.034). At least more than one grade improvement in the ASIA scale was observed in 80.5% of all patients. The local kyphosis Cobb angle at the injured segment averaged improved in both groups. CONCLUSION: A PLICS score ≥ 7 together with EULMF can be the threshold for posterior stabilization in addition to anterior reconstruction for the patients with SCFDs.

Comparison of robot-assisted and freehand pedicle screw placement for lumbar revision surgery.

BACKGROUND: The accuracy of robot-assisted pedicle screw implantation is a safe and effective method in lumbar surgery, but it still remains controversial in lumbar revision surgery. This study evaluated the clinical safety and accuracy of robot-assisted versus freehand pedicle screw implantation in lumbar revision surgery. METHODS: This was a retrospective study. From January 2018 to December 2019, 81 patients underwent posterior lumbar revision surgery in our hospital. Among them, 39 patients underwent revision surgery performed with robot-assisted pedicle screw implantation (Renaissance robotic system), whereas the remaining 42 patients underwent traditional freehand pedicle screw implantation. All patients underwent magnetic resonance imaging (MRI), computed tomography (CT), and X-ray before revision surgery. The sex, age, body mass index, bone mineral density, operative time, blood loss, operative segments, intra-operative fluoroscopy time, and complications were compared between the two groups. The accuracy of pedicle screw implantation was measured on CT scans based on Gertzbein Robbins grading, and the invasion of superior level facet joint was evaluated by Babu's method. RESULTS: There was no statistical difference about the baseline between the two groups (P > 0.05). Although there were no significant differences in operative time and complications between the two groups (P > 0.05), the robot-assisted group had significantly less intra-operative blood loss and shorter intra-operative fluoroscopy times than the freehand group (P < 0.05). In the robot-assisted group, a total of 267 screws were inserted, which were marked as grade A in 250, grade B in 13, grade C in four, and no grade D or E in any screw. In terms of invasion of superior level facet joint, a total of 78 screws were inserted in the robot-assisted group, which were marked as grade 0 in 73, grade 1 in four, grade 2 in one, and grade 3 in zero. By comparison, 288 screws were placed in total in the freehand group, which were rated as grade A in 251, grade B in 28, grade C in eight, grade D in one, and no grade E in any screw. A total of 82 superior level facet joint screws were inserted in freehand group, which were marked as grade 0 in 62, grade one in 18, grade 2 in two, and grade 3 in zero. The robot-assisted technique was statistically superior to the freehand method in the accuracy of screw placement (P < 0.05). CONCLUSION: Compared with freehand screw implantation, in lumbar revision surgery, the Renaissance robot had higher accuracy and safety of pedicle screw implantation, fewer superior level facet joint violations, and less intra-operative blood loss and intra-operative fluoroscopy time.

A Comparative Study of C2 Pedicle or Pars Screw Placement with Assistance from a 3-Dimensional (3D)-Printed Navigation Template versus C-Arm Based Navigation.

BACKGROUND Since C2 is adjacent to important nerves and blood vessels, the implantation risk of C2 internal fixation in this area is high and requires high accuracy. This study mainly discussed the application value of 3-dimensional (3D)-printed navigation template in C2 screw placement. MATERIAL AND METHODS A retrospective study compared 3D-printed navigation template-assisted screw placement (group A, n=32) and the C-arm based navigation-assisted screw placement group (group B, n=32). Group A was divided into 2 subgroups: A1 (C2 pedicle screw placement) and A2 (C2 pars screw placement); group B was divided into B1 (C2 pedicle screw placement) and B2 (C2 pars screw placement). The accuracy and safety of screw placement and clinical outcomes were evaluated. RESULTS There were 64 C2 screws placed in group A, and 95.31% achieved a grade A accuracy rating, including 52 screws in group A1 (96.15% grade A) and 12 screws in group A2 (91.67% grade A). A total of 64 C2 screws were placed in group B, and 84.38% achieved a grade A accuracy rating, including 50 screws in group B1 (84.00% grade A) and 14 screws in group B2 (85.71% grade A). The accuracy of screw placement differed significantly between groups A and B (P=0.041) and between groups A1 and B1 (P=0.039) but not between groups A2 and B2 (P=0.636). The postoperative efficacy of the 2 groups was satisfactory. And there were no complications of blood vessels or nerves related to screw placement in either group. CONCLUSIONS Although 3D-printed navigation template-assisted and C-arm based navigation-assisted C2 pedicle and pars screw placement provided similar safety and clinical efficacy, 3D-printed navigation template technology achieved more accurate C2 pedicle screw placement.

Accuracy of Robot-Assisted Percutaneous Pedicle Screw Placement for Treatment of Lumbar Spondylolisthesis: A Comparative Cohort Study.

BACKGROUND With the in-depth development of minimally invasive spine surgery in recent years, robot- and computer-assisted technologies have been increasingly used and successfully applied to spinal surgery. MATERIAL AND METHODS We performed a retrospective analysis of 60 patients with grade I or II lumbar spondylolisthesis who underwent minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) from January 2017 to December 2017. A robot-assisted surgical system was used in 30 patients for pedicle screw placement. The other 30 patients underwent fluoroscopy-guided percutaneous pedicle screw placement. RESULTS There were 130 screws placed under fluoroscopic guidance, with 26.2% penetration of the pedicle wall. There were 130 screws placed in robotic-assisted surgery, with 6.2% penetration of the pedicle wall. Severe screw deviation (Neo grade III) was identified in 4 screws in the fluoroscopy-guided group, while no severe deviation was noted in the robot-assisted group. In the fluoroscopic group, 15.6% of screws penetrated the superior articular process, and 2.1% screws had severe complications (Babu grade III). However, only 5.1% of screws in the robot-assisted group had severe complications. The mean screw insertion angle was significantly greater in the robot-assisted group than in the fluoroscopy-guided group (23.8±6.1° vs. 18.4±7.2°, P=0.017). CONCLUSIONS Compared to fluoroscopy-guided percutaneous pedicle screw placement, robot-assisted percutaneous pedicle screw placement has the following advantages: greater accuracy, lower incidences of screw penetration of the pedicle wall and invasion of the facet joints, and better screw insertion angle. Combined with MIS-TLIF, robot-assisted percutaneous pedicle screw placement is an effective minimally invasive treatment for lumbar spondylolisthesis.

Suboccipital neuralgia after C1 pedicle screw insertion: do we neglect atlantooccipital joint violation? - Case report and literature review.

BACKGROUND: Occipital neuralgia is one of the postoperative complications of C1 lateral mass screw insertion, which was deemed to be related with the C2 nerve root dysfunction. CASE PRESENTATION: A 52-year-old female patient presented with gradually progressive numbness and weakness in her extremities for 6 months. X-ray and computed tomography (CT) scan revealed obvious anterior atlantoaxial dislocation (ADD), which was reducible on extensive view. Atlantoaxial pedicle screw fixation and bone graft was performed. Immediately after the operation, the neurological symptom significantly improved. The patient complained of restricted cervical rotation and suboccipital neuralgia which was exacerbated by rotation with an intensity of 7 on a visual analog scale (VAS) ranging from 0 to 10 at postoperative day 5. While a satisfactory reduction was detected in the postoperative CT, violation of the left atlantooccipital joint was observed in the left C1 screw. Nimesulide (daily dosage of 0.2 g) and bracing were recommended immediately. At the 2 month follow-up, both the neurological improvement and reduction were maintained. The VAS of suboccipital neuralgia is 3 and decreased to 1 at 6 months postoperative. Bony fusion of the left atlantooccipital joint was confirmed by CT scan at 6 months postoperative. The patient complained that the suboccipital neuralgia was tolerable without the assistance of braces or medications for pain. At the 18 month follow-up, only stiffness of head flexion and rotation was observed without suboccipital neuralgia. CONCLUSION: Suboccipital neuralgia after atlantooccipital joint violation of C1 pedicle screw placement most likely results from C1 nerve root irritation. As the corresponding dermatome differs from the distributing region and aggravated factor of C2 nerve root dysfunction, neuralgia due to C1 irritation was only localized at suboccipital region and exacerbated by rotation.

Acute massive cerebellar infarction associated with craniocervical junction complex malformation: a case report and literature review.

We report a case of acute massive cerebellar infarction associated with craniocervical junction (CVJ) complex malformation in a 21-year-old male. Timely surgical intervention prevented the deterioration of his neurological status.

Cause Analysis of Open Surgery Used After Percutaneous Vertebroplasty and Kyphoplasty.

BACKGROUND The aim of this study was to analyze reasons why open surgery was done after percutaneous vertebroplasty and kyphoplasty. MATERIAL AND METHODS Patients (587 vertebral bodies) treated with percutaneous vertebroplasty or kyphoplasty in the Xi'an Honghui Hospital of Shanxi Province from January 2008 to January 2012 were retrospectively analyzed and 13 patients were enrolled in the study. These 13 patients had serious adverse events after percutaneous vertebroplasty or kyphoplasty. Their average age was 64.5 years old. Nine patients had spinal cord injury and 4 had nerve root injury. All the patients underwent open surgery within 4-12 h after definitive diagnosis. RESULTS All 13 cases were followed up (average time 14.1 months, range 3-47 months). Reasons for open surgery included cement extravasation (6 cases, 46.2%), puncture mistake (3 cases, 23.1%), and false selection of indications (4 cases, 30.8%). At last follow-up, skin feeling was better than that before open surgery in 4 cases with nerve root injury, and muscle strength recovered to grade 5 (3 cases) and grade 4 (1 case). In 9 cases with spinal cord injury, 7 patients improved and 2 remained at the same ASIA level. CONCLUSIONS The main reasons for open surgery after percutaneous vertebroplasty and kyphoplasty were cement extravasation (the most common reason), puncture mistake, and false selection of indications.

A prospective, double-blind, randomized controlled trial of treatment of atlantoaxial instability with C1 posterior arches >4 mm by comparing C1 pedicle with lateral mass screws fixation.

BACKGROUND: C1 posterior arch screw placement is one of the most effective treatments for atlantoaxial instability (AAI), which can be performed by either pedicle or lateral mass screw fixation. This study attempted to compare the feasibility and clinical outcomes of C1 pedicle with lateral mass screw fixations for treatment of AAI with C1 posterior arches >4 mm. METHODS: A total of 140 patients with AAI (C1 posterior arches measuring >4 mm) was enrolled in this single-center, randomized, double-blind trial. The subjects were randomly assigned into two treatments: C1 pedicle (group A) or lateral mass (group B) screw fixation. The patients, independent evaluating physicians and radiologists were blinded throughout the entire study. Patients were assessed before operation and in a series of follow-ups at 6 weeks, 6 months, 1 year, and 3 years post-surgery. The operation time, volume of blood loss, intraoperative complications, bone fusion rates, Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores were monitored. RESULTS: All 140 patients showed overall improvements in clinical symptoms after surgery. The mean follow-up time was 24.5 ± 13.0 months. In both groups, the mean JOA scores improved significantly at the time of final follow-up as compared to prior surgery (group A: 7.1 ± 1.4 vs 13.7 ± 1.9; group B:7.3 ± 1.8 vs 13.1 ± 1.4; improvement rates: 87.2% (group A) and 86.5% (group B)). The VAS scores also decreased significantly in both groups at the time of final follow-up as compared to prior surgery (group A: 6.0 ± 1.3 vs 1.7 ± 0.8, and group B: 5.7 ± 1.1 vs 2.1 ± 1.2). Bone fusion was achieved within 12 months postoperatively in the patients from both groups. The operation time was significantly shorter and volume of blood loss was significantly less in the patients from group A as compared to group B (p < 0.01). Furthermore, thirteen patients had burst bleeding from the C1-2 venous plexus and nine patients had immediate pain and numbness in the occipitocervical region due to C2 nerve roots irritation during lateral mass screw replacement, which were not observed in the patients with C1 pedicle screw insertion. No complications such as screw loosening, shifting, breakage, or AAI were observed in both groups. CONCLUSIONS: C1 pedicle screw fixation is less invasive and simpler, and has fewer complications. It renders better clinical outcomes than lateral mass screw fixation for treatment of AAI. TRIAL REGISTRATION: Current Controlled Trials ChiCTR-IOR-15006748 .

Transoral anterior release, odontoid partial resection, and reduction with posterior fusion for the treatment of irreducible atlantoaxial dislocation caused by odontoid fracture malunion.

PURPOSE: Several techniques have been introduced to manage irreducible atlantoaxial dislocation (IAAD). However, no study has reported the surgical method for the management of IAAD caused by odontoid fracture malunion. This study aimed to introduce a surgical method of transoral anterior release, odontoid partial resection, and reduction with sequential posterior fusion for the treatment of IAAD caused by odontoid fracture malunion. We also evaluated the clinical efficacy of this surgery. METHODS: This study included seven cases of IAAD caused by odontoid fracture malunion, collected from January 2008 to January 2011. Anterior atlantoaxial release was performed through anterior transoral approach, followed by partial resection of the odontoid process. C1-C2 were then fixed through pedicle screws and rods, and then fused posteriorly by single stage. Neurologic status was evaluated using the Japanese Orthopaedic Association (JOA) scoring system. RESULTS: All seven patients had complete release, and satisfactory reduction. Bony fusion was seen in all patients postoperatively. The patients were followed up for an average of 19.6 months (ranged from 9 to 36 months). The average of patients JOA scores at the final follow-up was significantly higher than that of their preoperative scores. Furthermore, the average improvement in neurological function was 87.4 %. No screw loosening, implant migration or implant failures, atlantoaxial redislocation, or signs of instability were observed in any of the patients during the follow-up period. CONCLUSIONS: Transoral anterior release, odontoid partial resection, and reduction combined with posterior fusion are effective, reliable, and safe procedures for the treatment of IAAD caused by odontoid fracture malunion.

Surgical treatment of scoliosis associated with syringomyelia with no or minor neurologic symptom.

PURPOSE: Syringomyelia with coexisting intraspinal abnormities is thought to increase the risk of neurologic injury during surgical correction of the scoliosis. However, surgical treatment for intraspinal abnormities carries significant morbidity risks including worsening neurological function and wound complications. The authors' aim in this study was to evaluate one-stage posterior correction of scoliosis in this patient population without prophylactic surgical treatment for neural axis malformations before scoliosis correction. METHODS: A total of 29 patients with syringomyelia and coexisting intraspinal abnormities who underwent scoliosis correction were evaluated. The average age was 15.6 years (range 12-23). All patients were examined for neural axis abnormalities using MRI, including syringomyelia with Chiari I malformation in 18 patients, syringomyelia with tethered cord and/or diastematomyelia in 11. None of patients presented with symptoms suggesting significant neurological dysfunction. The surgical efficacies and complications of correction were reviewed. RESULTS: The preoperative Cobb angle of major coronal curve averaged 65° (range 46°-95°), and it measured 28° (range 22°-43°) at the last follow-up, for a 63 % correction. Maximal kyphosis averaged 52° (range 41°-69°) preoperatively, and improved to 29° (range 22°-43°) at ultimate follow-up, for a 46 % correction. The average follow-up was 6 years (4-8 years). None of the patients experienced deterioration in their neurologic status. CONCLUSION: The study results suggested that prophylactic neurosurgery for intraspinal abnormality may be unnecessary in patients with asymptomatic or minor symptomatic syringomyelia and coexisting intraspinal abnormities. One-stage posterior correction of scoliosis in this patient population does not involve significant complications and seems to be an alternative and safe treatment option.

Prospective, Self-controlled, Comparative Study of Transposterior Arch Lateral Mass Screw Fixation and Lateral Mass Screw Fixation of the Atlas in the Treatment of Atlantoaxial Instability.

STUDY DESIGN: A prospective self-controlled study. OBJECTIVE: The aim of the present study was to compare the application and clinical outcomes of transposterior arch lateral mass screw and lateral mass screw fixation of the atlas in the treatment of atlantoaxial instability. SUMMARY OF BACKGROUND DATA: Atlas posterior screw fixation techniques comprise transposterior arch lateral mass screw fixation and lateral mass screw fixation. Previous studies have focused mainly on the feasibility of the anatomy and the biomechanics of the methods. METHODS: From June 2006 to February 2011, 66 patients with atlantoaxial instability were randomly assigned for treatment with transposterior arch lateral mass screw or lateral mass screw fixation of the atlas, combined with axis pedicle screw fixation. Patients were followed up regularly. The operation time, blood loss, intraoperative complications, Japan Department of Orthopedics Association Score, visual analog scale score, and bone fusion rates were recorded. RESULTS: The operation was successful in all 66 cases, with all patients showing improvement in clinical symptoms. There were significant differences in operation time and blood loss between the 2 groups (P<0.001). The mean follow-up time was 49 months. At the final follow-up, the Japan Department of Orthopedics Association score was significantly better than the preoperative score (mean, 13.5; P<0.05). The mean postoperative improvement rate was 88.2% and the mean visual analog scale score was 1.9; both results were significant as compared with preoperative results (P<0.05). Bone fusion was achieved within 6 months after operation. No screw loosening, shifting, breakage, or atlantoaxial instability was observed. Six patients with atlas lateral mass screw placement had burst bleeding of C1-C2 venous plexus during surgery. Five patients had immediate pain and numbness at the occipitocervical region. CONCLUSIONS: Atlas transposterior arch lateral mass screw fixation is less invasive, simple, has fewer complications, and offers good fixation results for atlantoaxial instability as compared with lateral mass screw fixation.

Treatment strategies for the surgical complications of thoracic spinal stenosis: a retrospective analysis of two hundred and eighty three cases.

PURPOSE: Our aim was to investigate the causes of and treatment strategies for surgical complications of thoracic spinal stenosis. METHODS: Between May 1990 and May 2010, 283 patients with thoracic spinal stenosis were treated in our department. Three physicians were assigned to patient follow-up. Patient medical records and radiographs were reviewed. Complications were categorised as perioperative, mid- to long-term and donor-site. RESULTS: Follow-up was completed for 254 patients; 249 patients survived. Follow-up time ranged from one to 19 years, with a mean of six years and two months. There were 107 cases with complications an incidence rate of 42.1%. Eleven cases were pulmonary infection, seven transient nerve-root injury, three pulmonary injury and one vertebral canal haematoma, all of which resolved. Thirteen cases of spinal cord injury postoperatively were treated using dehydration and corticosteroid therapy; eight recovered to the preoperation level, and five deteriorated. Eleven cases resulted in dural injury, and four led to cerebrospinal fluid leakage. There were five cases of wound-fat liquefaction and one of wound infection. Seven cases with deep venous thrombosis of the lower limb resolved by elevating the affected limb and administration of low-molecular-weight dextran. Seven cases of delayed wound healing recovered following change of dressings and antibiotic administration. Four cases of delayed bone-graft fusion recovered by extending the external fixation time. One case of bone-graft absorption was treated by iliac bone grafting and bracing. Two cases of internal fixation breakage were treated by removing the internal fixation. CONCLUSIONS: Thoracic spinal stenosis surgery may result in various complications but has a good prognosis with proper treatment. The key points in reducing complications are the surgeon's familiarity with operative imperatives and the appropriate surgical approach.

[Effectiveness of unilateral percutaneous vertebroplasty for elderly osteoporotic vertebral compression fracture by different approaches with different symptom severity].

Objective: To explore the effectiveness of unilateral percutaneous vertebroplasty (PVP) through mild side and severe side approaches in the treatment of elderly osteoporotic vertebral compression fracture (OVCF). Methods: The clinical data of 100 patients with OVCF with symptoms on one side who were admitted between June 2020 and June 2021 and met the selection criteria were retrospectively analyzed. The patients were divided into the severe side approach group (group A) and the mild side approach group (group B) according to the cement puncture access during PVP, with 50 cases in each group. There was no significant difference between the two groups in terms of general information such as gender composition, age, body mass index, bone density, damaged segments, disease duration, and chronic comorbidities ( P>0.05). The lateral margin height of the vertebral body on the operated side in group B was significantly higher than that of group A ( P<0.001). The pain level and spinal motor function were evaluated using the pain visual analogue scale (VAS) score and Oswestry disability index (ODI) before operation, at 1 day, 1 month, 3 months, and 12 months after operation in both groups, respectively. Results: No intraoperative or postoperative complications such as bone cement allergy, fever, incision infection, and transient hypotension occurred in both groups. Four cases of bone cement leakage occurred in group A (3 cases of intervertebral leakage and 1 case of paravertebral leakage), and 6 cases of bone cement leakage occurred in group B (4 cases of intervertebral leakage, 1 case of paravertebral leakage, and 1 case of spinal canal leakage), and none of them had neurological symptoms. Patients in both groups were followed up 12-16 months, with a mean of 13.3 months. All fractures healed and the healing time ranged from 2 to 4 months, with a mean of 2.9 months. The patients had no complication related to infection, adjacent vertebral fracture, or vascular embolism during follow-up. At 3 months postoperatively, the lateral margin height of the vertebral body on the operated side in groups A and B were improved when compared with preoperative ones, and the difference between pre- and post-operative lateral margin height of the vertebral body in group A was higher than that in group B, all showing significant differences ( P<0.001). The VAS scores and ODI in both groups improved significantly at all postoperative time points when compared with those before operation, and further improved with time after operation ( P<0.05). The differences in VAS scores and ODI between the two groups before operation were not significant ( P>0.05); VAS scores and ODI in group A were significantly better than those in group B at 1 day, 1 month, and 3 months after operation ( P<0.05), but no significant difference was found between the two groups at 12 months after operation ( P>0.05). Conclusion: Patients with OVCF have more severe compression on the more symptomatic side of the vertebral body, and patients with PVP have better pain relief and better functional recovery when cement is injected through the severe symptomatic side.

Roles of p38 MAPK signalling in intervertebral disc degeneration.

Intervertebral disc degeneration (IVDD) is a common degenerative disease mediated by multiple factors. Because of its complex aetiology and pathology, no specific molecular mechanisms have yet been identified and no definitive treatments are currently available for IVDD. p38 mitogen-activated protein kinase (MAPK) signalling, part of the serine and threonine (Ser/Thr) protein kinases family, is associated with the progression of IVDD, by mediating the inflammatory response, increasing extracellular matrix (ECM) degradation, promoting cell apoptosis and senescence and suppressing cell proliferation and autophagy. Meanwhile, the inhibition of p38 MAPK signalling has a significant effect on IVDD treatment. In this review, we first summarize the regulation of p38 MAPK signalling and then highlight the changes in the expression of p38 MAPK signalling and their impact on pathological process of IVDD. Moreover, we discuss the current applications and future prospects of p38 MAPK as a therapeutic target for IVDD treatment.

Does the Choice of Operative Side Affect the Clinical Outcome of Unilateral Percutaneous Kyphoplasty for Osteoporotic Vertebral Compression Fracture?

BACKGROUND: Studies have found that the rate of improvement in pain after percutaneous kyphoplasty (PKP) is 49% to 90%, and there are still some patients who may continue to sustain intractable back pain after surgery. OBJECTIVES: To compare the clinical efficacy and imaging results between unilateral PKP performed from the symptom-dominating side and the non-dominating side in OVCF treatment. STUDY DESIGN: Prospective study. SETTING: All data were from Honghui Hospital in Xi'an. METHODS: One hundred forty-two patients of osteoporotic vertebral compression fracture (OVCF) treated with unilateral PKP were eventually recruited and randomly assigned to either the A or B group. Patients in group A received PKP from the symptom-dominating side; patients in group B received PKP from the symptom non-dominating side. The demographic characteristics, related surgical information, and complications observed within both groups were recorded. The clinical outcomes evaluation included the visual analog scale (VAS) score for low back pain and the Oswestry Disability Index (ODI). Evaluation of imaging results included anterior height (AH), kyphosis angulation (KA), and contralateral distribution rate of bone cement. RESULTS: One hundred eighteen patients (48 men and 70 women; age range: 60-83 years), including 59 patients in the A group and 59 patients in the B group, were available for the complete assessment. There were 5 cases and 7 cases of bone cement leakage in groups A and B, respectively, which were asymptomatic para-vertebral or inter-vertebral leakage without intra-spinal leakage. Compared with the preoperative data, significant improvements in the VAS scores and ODI were observed at each follow-up interval. The VAS score and ODI in the A group were significantly lower than in the B group only within 2 months (P < 0.05). Compared with the preoperative data, the AH and KA in the 2 groups were improved (P < 0.05). There was no significant difference in AH and KA between the 2 groups at each follow-up interval (P > 0.05). LIMITATIONS: A single-center study. CONCLUSIONS: The unilateral PKP performed via the symptom-dominating side can effectively relieve back pain and improve the patient's quality of life at the early stage.

Biomechanical effects of different lateral mass injury patterns on subaxial cervical fracture dislocations after anterior cervical surgery: a finite element study.

OBJECTIVE: The lateral mass joint plays an important role in maintaining the mechanical stability of the subaxial cervical spine. We first performed a three-dimensional finite element (FE) biomechanical study to evaluate the local mechanical stability of subaxial cervical fracture dislocations after anterior-only fixation for lateral mass injuries of varying severity. METHODS: A three-dimensional FE model of the subaxial cervical spine with simple anterior fixation for C5-6 fracture dislocation was reconstructed. According to their different morphological characteristics of unilateral lateral mass injuries, the lateral mass injury was divided into six types. The range of motion (ROM) of each part and the stress of the cage, each intervertebral disc, titanium plate, and screw stress were recorded. RESULTS: The ROM of C3-4, C4-5, C5-6, and C6-7 in type 4 was higher than that of the other five types. The maximum equivalent stress on C4-5 intervertebral discs, titanium plates, and screws in type 4 under various sports loads was higher than that produced by the other load types. In the stress cloud diagram of the front titanium plate and screws, the degree of stress was the highest in type 4. Stress placed on each part of the model, from high to low, was as follows: plate, screw, C6, C5, and C7. CONCLUSION: Greater injury severity is associated with higher stress on the plate and screw with exercise loads. Type 4 lateral mass injuries, characterized by ipsilateral pedicle and lamina junction fractures, significantly affected biomechanical stability after simple anterior fixation.

C1-ring osteosynthesis versus C1-2 fixation fusion in the treatment of unstable atlas fractures: a multicenter, prospective, randomized controlled study with 5-year follow-up.

OBJECTIVE: The aim of the present study was to compare the long-term effects of posterior C1-ring osteosynthesis and C1-2 fixation fusion in the treatment of unstable atlas fractures. METHODS: A multicenter, prospective, randomized controlled trial was conducted to analyze 73 patients with atlas fractures who underwent posterior fixation. The intervention group was treated with C1-ring osteosynthesis, and the control group was treated with C1-2 fixation fusion. The patients were followed up for 6 months, 1 year, 2 years, and 5 years after the operation. RESULTS: Fifty-two patients had complete data at the last follow-up. The visual analog scale (VAS) score for neck pain in the intervention group was lower than that in the control group (p < 0.001). The operation time, intraoperative blood loss, radiation dose, bedridden period, hospital stay, and cost in the intervention group were significantly lower than those in the control group (p < 0.001). At the last follow-up, the Neck Disability Index in the intervention group was higher than that of the control group, and the angle of flexion-extension and axial rotation in the intervention group were greater than those in the control group (p < 0.001). CONCLUSIONS: In this study, the authors found that posterior C1-ring osteosynthesis is superior to C1-2 fixation fusion in terms of long-term relief of neck pain and preservation of the physiological function of the cervical vertebrae. This technique is a reliable choice for the treatment of unstable C1 fractures.

[Study on robot-assisted pedicle screw implantation in adolescent idiopathic scoliosis surgery].

OBJECTIVE: To investigate the safety and accuracy of robot-assisted pedicle screw implantation in the adolescent idiopathic scoliosis (AIS) surgery. METHODS: The clinical data of 46 patients with AIS who were treated with orthopedics, bone graft fusion, and internal fixation via posterior approach between June 2018 and December 2019 were analyzed retrospectively. Among them, 22 cases were treated with robot-assisted pedicle screw implantation (robot group) and 24 cases with manual pedicle screw implantation without robot assistance (control group). There was no significant difference in gender, age, body mass index, Lenke classification, and preoperative Cobb angle of the main curve, pain visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score between the two groups ( P>0.05). The intraoperative blood loss, pedicle screw implantation time, intraoperative pedicle screw adjustment times, and VAS and JOA scores after operation were recorded. The Cobb angle of the main curve was measured on X-ray film and the spinal correction rate was calculated. The screw position and the accuracy of screw implantation were evaluated on CT images. RESULTS: The operation completed successfully in the two groups. The intraoperative blood loss, pedicle screw implantation time, and pedicle screw adjustment times in the robot group were significantly less than those in the control group ( P<0.05). There was 1 case of poor wound healing in the robot group and 2 cases of mild nerve root injury and 2 cases of poor incision healing in the control group, and there was no significant difference in the incidence of complications between the two groups ( P=0.667). All patients in the two groups were followed up 3-9 months (mean, 6.4 months). The VAS and JOA scores at last follow-up in the two groups were superior to those before operation ( P<0.05), but there was no significant difference in the difference of pre- and post-operative scores between the two groups ( P>0.05). The imaging review showed that 343 screws were implanted in the robot group and 374 screws in the control group. There were significant differences in pedicle screw implantation classification and accuracy between the two groups (89.5% vs 79.1%)( Z=-3.964, P=0.000; χ 2=14.361, P=0.000). At last follow-up, the Cobb angles of the main curve in the two groups were significantly lower than those before operation ( P<0.05), and there was significant difference in the difference of pre- and post-operative Cobb angles between the two groups ( t=0.999, P=0.323). The spinal correction rateswere 79.82%±5.33% in the robot group and 79.62%±5.58% in the control group, showing no significant difference ( t=0.120, P=0.905). CONCLUSION: Compared with manual pedicle screw implantation, robot-assisted pedicle screw implantation in AIS surgery is safer, less invasive, and more accurate.

Risk Factors for New Vertebral Fracture After Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures.

PURPOSE: To analyze the risk factors for new vertebral fractures after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs). PATIENTS AND METHODS: We retrospectively reviewed the records of patients with symptomatic OVCFs who underwent PVP in our hospital, from January 2014 to January 2019. Demographic and lifestyle data on the presence of underlying chronic disease, preoperative bone mineral density, details of vertebral fractures, postoperative osteoporosis treatment, and new fracture development were collected. Patients were divided into postoperative fracture and non-fracture groups. To identify the independent risk factors for new vertebral fracture development, variables significant on univariate analysis were included in a multivariate regression model. RESULTS: Of the 2202 patients treated with PVP, 362 (16.43%) had a new postoperative vertebral fracture. All patients were followed up for >12 months (mean 14.7 months). Univariate analysis revealed no significant difference in height; body weight; preoperative bone mineral density; number of fractured vertebrae; injection volume of bone cement in a single vertebra; leakage rate of bone cement; or presence of hypertension, coronary heart disease, and chronic obstructive pulmonary disease between the fracture and non-fracture groups (P>0.05). Age, sex, smoking, alcohol consumption, diabetes mellitus, postoperative exercise, and postoperative osteoporosis treatment were associated with new vertebral fractures (all P<0.05). A multivariate analysis showed that age (odds ratio [OR]=1.212, P<0.0001), female sex (OR=1.917, P<0.0001), smoking (OR=1.538, P=0.026), and diabetes (OR=1.915, P<0.0001) were positively correlated with new vertebral fracture development, whereas postoperative exercise (OR=0.220, P<0.0001) and osteoporosis treatment (OR=0.413, P<0.0001) were negatively correlated. CONCLUSION: Elderly patients, females, and those with a history of smoking and diabetes are at high risk of new vertebral fracture after PVP. Patients should be encouraged to stop smoking and consuming alcohol, control blood glucose level, participate in sufficient physical activity, and adhere to osteoporosis treatment to prevent new vertebral fractures.