Comparison of Skeletal Stability after Le Fort I Osteotomy With Bone Fixation Using Biodegradable and Titanium Systems: A Retrospective Study.

The titanium osteosynthesis system used for fixing bone segments after maxillary osteotomy provides reliable outcomes owing to its biocompatibility and adequate strength. In addition, several studies have evaluated the skeletal stability after maxillary osteotomy with fixation using a biodegradable system. However, the indications for applying a biodegradable system after maxillary osteotomy remain controversial. Therefore, this study aimed to compare the long-term skeletal stability of bone segments after maxillary osteotomy with bone fixation using biodegradable and titanium osteosynthesis systems and to assess the usefulness of a biodegradable osteosynthesis system. Patients who underwent Le Fort I osteotomy of the maxilla to correct jaw deformities between April 2008 and March 2021 were included in this study. A total of 45 patients were included, with 28 in the biodegradable osteosynthesis system group and 17 in the titanium group. Cephalometric and computed tomography analyses were performed to evaluate the skeletal stability of the bone segments after maxillary osteotomy with bone fixation using biodegradable or titanium osteosynthesis systems. The maxillary segment was repositioned anteriorly with a clockwise rotation. Skeletal stability was similar between the biodegradable and titanium osteosynthesis systems. Segmental changes occurred mainly in the first 6 months after surgery, and the segment was completely stable between 6 and 12 months after surgery. This study revealed no significant differences in skeletal stability after maxillary osteotomy between the biodegradable and titanium osteosynthesis systems. However, the findings in this study should be interpreted with caution owing to the small sample size and small amount of maxillary-segment movement.

Molecular insights and the role of 18F-FDG-PET/CT in the diagnosis of spinal gliomas.

BACKGROUND: In recent years, molecular findings on spinal gliomas have become increasingly important. This study aimed to investigate the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in the diagnosis of spinal glioma. METHODS: This study included patients diagnosed with spinal cord glioma who underwent 18F-FDG-PET examination at the Department of Neurosurgery, Nagoya University Hospital between January 2016 and November 2023. The gliomas were divided into two groups, high-grade and low-grade, based on pathological and molecular studies. The maximum standardized uptake values (SUVmax) of the tumors were quantified and subsequently represented using receiver operating characteristic (ROC) curves. RESULTS: Eighteen participants were included in this study. Of the participants, seven had high-grade glioma with an SUVmax of 6.76 ± 0.72, and eleven had low-grade glioma with an SUVmax of 4.02 ± 1.78, and a statistically significant difference between the two groups. The ROC curve delineated an SUVmax cutoff value of 5.650, with an area under the curve (AUC) of approximately 0.909. Based on the cutoff value, the results of the diagnostic performance rendered a sensitivity and negative predictive value of 1.0, whereas the specificity and positive predictive value were 0.909 and 0.875, respectively. CONCLUSIONS: The present study shows that 18F-FDG-PET exhibits a markedly sensitive and negative predictive value in the assessment of spinal gliomas. Additionally, these findings have potential implications for the qualitative assessment of spinal gliomas using 18F-FDG-PET/CT. This imaging modality may be useful for making timely treatment decisions in situations where a detailed diagnosis by molecular analysis is not possible.

Comparative Study of Surgical Outcomes of Occipitocervical and Atlantoaxial Fusion for Retro-Odontoid Pseudotumor.

OBJECTIVE: To compare the surgical and radiographic outcomes of occipitocervical fusion (OCF) with those of atlantoaxial fusion (AAF) in patients with cervical myelopathy caused by retroodontoid pseudotumors (ROPs). METHODS: This retrospective, comparative study included 26 patients; 12 underwent occipitocervical fusion (OCF) (group O) and 14 retroodontoid pseudotumor (AAF) (group A) with a minimum 2-year follow-up. Neurologic outcomes were evaluated using the Japanese Orthopedic Association (JOA) score. Radiologic assessment included the maximum anteroposterior (AP) diameter of the anteroposterior-retroodontoid pseudotumor (AP-ROP), C2-7 angle, O-C2 angle, C1-2 angle, atlantodental interval (ADI), range of motion (ROM) of the ADI, C2-C7 sagittal vertical axis (C2-7 SVA), and T1 slope. Global spinal alignments (pelvic incidence [PI] minus lumbar lordosis [LL] [PI-LL], pelvic tilt, sacral slope, and C7 sagittal vertical axis) were also compared between the groups. RESULTS: Both groups had equally good clinical outcomes with equal complication rates. Three patients had a three-level fusion, 5 cases had a four-level fusion, and 4 cases had more than five-level fusion in group O. All cases had a single-level fusion in group A. Surgical time was significantly shorter in group A. AP-ROP was significantly downsized postoperatively in both groups and was more prominent in group O. C2-7 SVA was significantly increased and C2-7A ROM was significantly reduced in group O at the final follow-up. The PI-LL showed a significant increase in group O at the final follow-up. CONCLUSIONS: Although OCF and AAF were similarly effective for cervical myelopathy with ROP, AAF was less invasive, and spinal alignment was better maintained postoperatively in AAF than OCF.

Surgical Outcomes of Common Peroneal Nerve Entrapment Neuropathy Associated with L5 Radiculopathy.

Impingement of the common peroneal nerve, a branch of the L5 nerve root, causes common peroneal nerve entrapment neuropathy (CPNE). Although there are cases of CPNE associated with L5 radiculopathy, surgical intervention's effectiveness remains to be elucidated. This retrospective case-control study aimed to evaluate the efficacy of surgery in patients with CPNE associated with L5 radiculopathy. Twenty-two patients (25 limbs) with surgically treated CPNE between 2015 and 2022 were retrospectively reviewed. The limbs were classified into two groups: group R (limbs of CPNE associated with L5 radiculopathy) and group O (limbs of CPNE without L5 radiculopathy). The durations from onset to surgery, the nerve conduction studies (NCSs), and postoperative improvement rates for motor weakness, pain, and dysesthesia were compared between the groups. Group R included 15 limbs (13 patients), and group O included 10 limbs (9 patients). There were no significant differences in the duration from onset to surgery or abnormal findings of NCS between the two groups. The postoperative improvement rates were 88% and 100% (p = 0.62) for muscle weakness, 87% and 80% (p = 0.53) for pain, and 71% and 56% (p = 0.37) for dysesthesia in group R and group O, respectively, without significant differences between groups. CPNE associated with L5 radiculopathy is common, and the results of the present study showed that the surgical outcomes in such cases were satisfactory and comparable to those in CPNE without L5 radiculopathy.

Evaluation of Posterior Ligamentous Complex Injury in Thoracolumbar Burst Fractures: Correlation Analysis of CT and MRI Findings.

The goal of this study is to perform correlation analysis of Computed tomography (CT) and magnetic resonance imaging (MRI) results in posterior ligament complex (PLC) injury and define the morphological traits of thoracolumbar (TL) burst fractures connected to PLC injury. Forty patients with surgically repaired TL burst fractures between January 2013 and December 2020 were retrospectively analyzed. The patients were split into two groups for comparison based on MRI (Group P: patients with a confirmed or suspected PLC injury; Group N: patients with PLC injury denied). The radiographic morphological examination based on CT scans and clinical evaluation was performed and compared between two groups. The thoracolumbar injury classification and severity score (TLICS), the load sharing classification (LSC) scores, and the number of patients with neurological impairments were considerably greater in Group P. Loss of height of the fracture (loss height), local kyphosis of the fracture (local kyphosis), and supraspinous distance were significantly higher in Group P and significantly associated with PLC injuries indicating severe vertebral body destruction and traumatic kyphosis in multivariate logistic analysis [odds ratio: 1.90, 1.06, and 1.13, respectively]. Cutoff value for local kyphosis obtained from the receiver operating characteristic curve was 18.8. If local kyphosis is greater than 18.8 degrees on CT scans, we should take into account the probability of the highly damaged burst fracture associated with PLC injury. In this situation, we should carefully assess MRI to identify the spinal cord injury or spinal cord compression in addition to PLC injury because these instances likely present with neurological abnormalities.

Comparative Study of Anterior Transvertebral Foraminotomy and Anterior Cervical Discectomy and Fusion for Unilateral Cervical Spondylotic Radiculopathy.

OBJECTIVE: To study the compared surgical and radiographic outcomes of Transvertebral foraminotomy (TVF) with anterior cervical discectomy and fusion (ACDF) in patients with unilateral cervical spondylotic radiculopathy (CSR). METHODS: We performed a retrospective comparative study of 72 consecutive patients with 1- or 2-level CSR treated with ACDF or TVF. 27 patients who underwent TVF (group T) and 45 patients who underwent ACDF (group A) with a minimum 2-year follow-up were enrolled. We evaluated clinical outcomes and radiological assessment. Clinical outcome included Visual analog scale (VAS) scores for axial, arm pain at preoperatively and final follow-up. VAS score for painful swallowing was also evaluated 1 week after surgery. Radiological assessment included C2-7 sagittal Cobb angle (C2-7 CA), range of motion (ROM) of C2-7 CA, the height, angle and ROM of the functional spinal unit (FSU), and tip of the spinous process of the operated segment. We also evaluated the disc height, FSU angle, and ROM of the FSU at the cranial adjacent segment. RESULTS: Both groups had good clinical outcomes. Soft tissue swelling was significantly less prominent in group T than that for group A. VAS scores for painful swallowing is lower in group T without significant difference. The ROM of C2-7 CA, FSU, and spinous processes demonstrated a significant reduction in group A compared with group T.(P < 0.05). Disc height at the cranial adjacent segment was maintained in group T. CONCLUSIONS: TVF is as effective as ACDF for unilateral CSR and preserves whole cervical spine and segmental alignment.

Downward penetrating endplate screw technique under O-arm navigation posterior fusion in patients with osteoporotic vertebral body fractures associated with diffuse idiopathic skeletal hyperostosis.

Background: A downward penetrating endplate screw (PES) technique combined with caudal anchor screws inserted in the upward direction under O-arm navigation (i.e., crossing screw technique) avoided screw backout and proximal junctional kyphosis (PJK) in three patients with osteoporotic vertebral body fractures and diffuse idiopathic skeletal hyperostosis (DISH). Methods: The PES techniques were utilized for patients with T12 (one patient) and L1 (two patients) spontaneous fusion across the targeted vertebrae, with minimal damage to the involved endplates/intervertebral discs. The average number of instrumented vertebrae was 5.3. Results: There were no perioperative complications over the mean follow-up period of 28.7 months; no screw loosening, and no PJK. Conclusion: The PES technique prevented screw backout, and PJK in three patients with lumbar osteoporotic vertebral fractures and DISH.

Spinal Cord Stimulation for Neuropathic Pain following a Spinal Cord Lesion with Past Spinal Surgical Histories Using a Paddle Lead Placed on the Rostral Side of the Lesion: Report of Three Cases.

Spinal cord parenchymal lesions may induce intractable neuropathic pain. However, the efficacy of conventional spinal cord stimulation for the neuropathic pain following spinal cord lesions remains to be controversial. In this study, we present three cases of spinal cord stimulation using a paddle lead at the rostral side of the spinal lesion causing pain symptoms. Good pain reductions were achieved using conventional stimulation in one case and using differential target multiplexed stimulation in two cases. Case 1: A 55-year-old man presented with neuropathic pain affecting his bilateral upper extremities due to a traumatic cervical spinal cord injury. Conventional stimulation via a paddle-type electrode was able to reduce the pain from 8 to 4 via a visual analog scale. Case 2: A 67-year-old man had undergone three spinal surgeries. He presented with pain and numbness of bilateral lower extremities due to a spinal cord lesion by thoracic disc herniation. Differential target multiplexed stimulation via a paddle-type electrode achieved excellent pain reduction, that is, from 9 to 2 on the visual analog scale. Case 3: An 80-year-old man presented with pain in his bilateral upper extremities due to a cervical spinal cord lesion caused by compression and spinal canal stenosis. Posterior cervical decompression and paddle-type electrode placement were performed simultaneously. Differential target multiplexed stimulation was able to achieve excellent pain reduction, from 7 to 2 on the visual analog scale. Spinal cord stimulation using a paddle lead at the rostral side of the spinal lesion and differential target multiplexed stimulation may provide significant opportunities for patients with intractable neuropathic pain following spinal cord lesions.

Safety and Validity of Anterior Cervical Disc Replacement for Single-level Cervical Disc Disease: Initial Two-year Follow-up of the Prospective Observational Post-marketing Surveillance Study for Japanese Patients.

Anterior cervical disc replacement (ACDR) using cervical artificial disc (CAD) has the advantage of maintaining the range of motion (ROM) at the surgical level, subsequently reducing the postoperative risk of adjacent disc disease. Following the approval for the clinical use in Japan, a post-marketing surveillance (PMS) study was conducted for two different types of CAD, namely, Mobi-C (metal-on-plastic design) and Prestige LP (metal-on-metal design). The objective of this prospective observational multicenter study was to analyze the first 2-year surgical results of the PMS study of 1-level ACDR in Japan. A total of 54 patients were registered (Mobi-C, n = 24, MC group; Prestige LP, n = 30, PLP group). Preoperative neurological assessment revealed radiculopathy in 31 patients (57.4%) and myelopathy in 15 patients (27.8%). Preoperative radiological assessment classified the disease category as disc herniation in 15 patients (27.8%), osteophyte in 6 patients (11.1%), and both in 33 patients (61.1%). The postoperative follow-up rates at 6 weeks, 6 months, 1 year, and 2 years after ACDR were 92.6%, 87.0%, 83.3%, and 79.6%, respectively. In both groups, patients' neurological condition improved significantly after surgery. Radiographic assessment revealed loss of mobility at the surgical level in 9.5% of patients in the MC group and in 9.1% of patients in the PLP group. No secondary surgeries at the initial surgical level and no serious adverse events were observed in either group. The present results suggest that 1-level ACDR is safe, although medium- to long-term follow-up is mandatory to further verify the validity of ACDR for Japanese patients.

Laminectomy triggers symptomatic growth of spinal schwannoma in a patient with schwannomatosis.

Background: Schwannomatosis (SWN) is genetically similar to neurofibromatosis type 2 (NF2) and represents a NF2 gene mutation. Previous studies have shown that these mutations in both neurons and Schwann cells can lead to the development of schwannomas after nerve crush injuries. Here, we reviewed the potential pathoanatomical mechanisms for the development of a trauma-induced spinal schwannomas in a 55-year-old male with SWN. Case Description: A 49-year-old male had originally undergone a L3-L5 lumbar laminectomy for stenosis; the schwannomas seen on the preoperative magnetic resonance imaging (MRI) were not resected. Now at age 55, he newly presented with low back pain and numbness in the left L5 dermatome, and he was diagnosed with an L4 vertebral level cauda equina tumor on MRI. Following gross-total resection, the histopathological assessment revealed a Ki-67 labeling index 5-10% in hotspots (i.e., slightly higher than the normal range of schwannomas) and a 20% mosaic loss of SMARCB1. Based on these criteria, he was diagnosed as having SWN. Conclusion: In this patient with SWN, compression/physical trauma to nerves of the cauda equina during the L3-L5 laminectomy 6 years ago likely caused the progression of schwannoma.

Radiological Analysis of Minimally Invasive Microscopic Laminectomy for Lumbar Canal Stenosis with a Focus on Multilevel Stenosis and Spondylolisthesis.

OBJECTIVE: We retrospectively compared the radiological and clinical outcomes of two different surgical techniques (lumbar spinous process splitting laminectomy [LSPSL] and unilateral laminotomy for bilateral decompression [ULBD]) to treat lumbar spinal canal stenosis (LCS). METHODS: We performed a retrospective comparative study of 141 consecutive patients with an average age of 70.8 ± 9.4 years who had undergone LSPSL or ULBD for LCS between April 2015 and April 2019. None of the patients had developed remote fractures of the spinous processes using either technique. These cases were divided into 2 groups: group L, 73 patients who had undergone LSPSL from April 2015 to April 2017; and group U, 68 patients who had undergone ULBD from May 2017 to April 2019. The clinical and radiological outcomes and surgical complications at the 1-year postoperative follow-up period were evaluated. RESULTS: We found no significant differences in the operative time between the 2 groups. However, group U had had significantly less blood loss than group L. The facet joints were significantly well preserved in group U. We examined the multilevel and spondylolisthesis cases separately and found that both surgical procedures were equally effective and that the visual analog scale scores for back or leg pain and Japanese Orthopaedic Association scores had significantly improved postoperatively in each group. Group U showed better outcomes in terms of LCS recurrence, with 3 patients in the group L requiring repeat surgery. CONCLUSIONS: We found both ULBD and LSPSL to be safe and effective techniques for LCS, even for patients with spondylolisthesis and multilevel disease. ULBD was superior in terms of recurrence prevention, preservation of the facet joints, and less blood loss.

Piecemeal resection of aggressive vertebral hemangioma using real-time navigation-guided drilling technique.

Vertebral hemangiomas are the most common benign vertebral tumors and are usually asymptomatic. Aggressive subtypes of the tumor, called aggressive VHs (AVHs), can become symptomatic with extraosseous extensions and require surgical removal. We present a case of AVH in a 36-year-old man presenting with low back pain and right leg pain that persisted for three months. Imaging studies showed a Th12 vertebral tumor that extended into the spinal canal and was squeezing the spinal cord. Computed tomography (CT)-guided biopsy indicated vertebral hemangimoa. Following preoperative arterial embolization, piecemeal gross total resection was attained under navigation guidance. He was left with no neurological deficit and remained well at the 12-month postoperative folow-up. Since AVHs are benign tumor, piecemeal removal of the tumor can be selected. However, disadvantage of the approach include difficulty of making decision how much to remove the front part of the vertebral body close to thoracic descending aorta. Furthermore, when the tumor tissue is too hard to curett, manipulation in tight spaces near the spinal cord carries the risk of damaging it. Navigation-guided drill is highly helpful for real-time monitoring of ongoing tumor resection. It enables safely resection of the tumor especially in the anterior cortical surface of the vertebral body and easily resection even hard tumors. This method results in reducing residual tumor and maintaining safety resection.

[Differential Diagnosis between Spinal Degenerative Disorder and Peripheral Nerve Entrapment Disease].

In the surgical treatment of spinal degenerative disorders, neural function improves to some extent upon successful neural decompression. However, we have witnessed cases with poor postoperative results. The causes include surgical procedure issues, such as insufficient decompression of neural tissues and overlooking sites to be decompressed, and neurological misdiagnosis of other causative lesions or multiple lesions. Here, as necessary knowledge for spine surgeons dealing with spinal cord degenerative disorders to prevent poor surgical results, we have discussed the differentiation of peripheral nerve entrapment neuropathy from spinal degenerative disorders. Specifically, we have focused on L5 radiculopathy or common peroneal nerve entrapment disorder and C8 radiculopathy or thoracic outlet syndrome or ulnar nerve entrapment neuropathy, which are difficult to distinguish, and have explained the difference in their neurological symptoms from an anatomical perspective. We have also described the differential diagnosis of drop fingers, which is one of the neurological symptoms, and have mentioned the possibility of diseases managed by neurologists, which neurosurgeons should know about.

Gene-Activated Matrix with Self-Assembly Anionic Nano-Device Containing Plasmid DNAs for Rat Cranial Bone Augmentation.

We have developed nanoballs, a biocompatible self-assembly nano-vector based on electrostatic interactions that arrange anionic macromolecules to polymeric nanomaterials to create nucleic acid carriers. Nanoballs exhibit low cytotoxicity and high transfection efficiently in vivo. This study investigated whether a gene-activated matrix (GAM) composed of nanoballs containing plasmid (p) DNAs encoding bone morphogenetic protein 4 (pBMP4) could promote bone augmentation with a small amount of DNA compared to that composed of naked pDNAs. We prepared nanoballs (BMP4-nanoballs) constructed with pBMP4 and dendrigraft poly-L-lysine (DGL, a cationic polymer) coated by γ-polyglutamic acid (γ-PGA; an anionic polymer), and determined their biological functions in vitro and in vivo. Next, GAMs were manufactured by mixing nanoballs with 2% atelocollagen and ß-tricalcium phosphate (ß-TCP) granules and lyophilizing them for bone augmentation. The GAMs were then transplanted to rat cranial bone surfaces under the periosteum. From the initial stage, infiltrated macrophages and mesenchymal progenitor cells took up the nanoballs, and their anti-inflammatory and osteoblastic differentiations were promoted over time. Subsequently, bone augmentation was clearly recognized for up to 8 weeks in transplanted GAMs containing BMP4-nanoballs. Notably, only 1 µg of BMP4-nanoballs induced a sufficient volume of new bone, while 1000 µg of naked pDNAs were required to induce the same level of bone augmentation. These data suggest that applying this anionic vector to the appropriate matrices can facilitate GAM-based bone engineering.

Driver Genetic Mutations in Spinal Cord Gliomas Direct the Degree of Functional Impairment in Tumor-Associated Spinal Cord Injury.

Genetic analysis in glioma has been developed recently. Spinal cord glioma is less common than intracranial glioma. Thus, the clinical significance of genetic mutations in spinal cord gliomas remains unclear. Furthermore, because the spinal cord is an important communication channel between the brain and the rest of the body, increased attention should be paid to its functional prognosis. In this study, we investigated the functional prognosis and driver genetic mutations in eight patients with spinal cord gliomas (World Health Organization grade I, three cases; grade II, two cases; grade III/IV, three cases). IDH mutations were detected in all grade II cases and H3F3A mutations were detected in all grade III/IV cases. The functional status of grade I and II gliomas remained unchanged or improved 1 year after surgery, whereas grade III/IV gliomas remained unchanged or deteriorated. Spinal glioma progenitor cells with H3F3A mutations were associated with accelerated tumor-associated spinal cord injury, which led to functional impairment. Conversely, the presence of IDH mutations, which are rarely reported in spinal gliomas, indicated a relatively favorable functional prognosis.

Endotracheal Tube Obstruction Experienced during an Anterior Cervical Discectomy and Fusion.

During anterior cervical discectomy and fusion (ACDF), endotracheal tube difficulties are anticipated at the operative level but are unexpected elsewhere in the airway. We report the case of a 66-year-old woman who underwent C4/C5 ACDF to treat adjacent segment disease following a previous anterior cervical fixation surgery. Shortly after her lower jaw was elevated and the fusion cage was inserted, a rise in airway pressure was observed, indicating impaired breathing. Subsequent examination revealed a bent endotracheal tube in the oral cavity as the cause of the respiratory impairment. During anterior cervical surgery, elevating the lower jaw can cause the tongue root to press against the endotracheal tube. Reinforced endotracheal tubes, with a spiral-wound wire in the inner wall, would effectively prevent this issue. In the unlikely event of impaired breathing during such an operation, the oral cavity should be inspected for confirmation of an open airway.

Clinical Safety Assessment of Autologous Freeze-Drying Platelet-Rich Plasma for Bone Regeneration in Maxillary Sinus Floor Augmentation: A Pilot Study.

The purpose of this clinical study is to evaluate the safety and preliminary efficacy of autologous freeze-drying platelet-rich plasma (FD-PRP) on bone regeneration in maxillary sinus floor augmentation as a preliminary pilot study. Five patients that required sinus floor augmentation to facilitate the placement of dental implants participated in this clinical study. The PRP was prepared from the autologous peripheral blood and was lyophilized and stored at -20 °C for 4 weeks before surgery. At surgery, triple-concentrated FD-PRP (x3FD-PRP) mixed with synthetic bone grafting materials was rehydrated following the transplantation into the sinus floor. The primary outcome was a safety verification of x3FD-PRP, evaluated in terms of the clinical course and consecutive blood tests. The secondary outcome was clinical efficacy focused on bone regeneration in sinus floor augmentation evaluated by radiographic examination and implant stability. There were no adverse events, such as systemic complications, excessive inflammatory reactions, severe infection, or local site healing complications, besides those on the usual course associated with surgery. Vertical augmented height was maintained, and the initial stability of implants was achieved post-operatively in 6 months. The results obtained in this study suggest that x3FD-PRP can be used safely for bone engineering in clinical practice. Further studies are required to draw a conclusion concerning the efficacy of x3FD-PRP since this was a pilot study with a single arm and a small sample size.

Gene-activated matrix harboring a miR20a-expressing plasmid promotes rat cranial bone augmentation.

Gene-activated matrix (GAM) has a potential usefulness in bone engineering as an alternate strategy for the lasting release of osteogenic proteins but efficient methods to generate non-viral GAM remain to be established. In this study, we investigated whether an atelocollagen-based GAM containing naked-plasmid (p) DNAs encoding microRNA (miR) 20a, which may promote osteogenesis in vivo via multiple pathways associated with the osteogenic differentiation of mesenchymal stem/progenitor cells (MSCs), facilitates rat cranial bone augmentation. First, we confirmed the osteoblastic differentiation functions of generated pDNA encoding miR20a (pmiR20a) in vitro, and its transfection regulated the expression of several of target genes, such as Bambi1 and PPARγ, in rat bone marrow MSCs and induced the increased expression of BMP4. Then, when GAMs fabricated by mixing 100 µl of 2% bovine atelocollagen, 20 mg ß-TCP granules and 0.5 mg (3.3 µg/µl) AcGFP plasmid-vectors encoding miR20a were transplanted to rat cranial bone surface, the promoted vertical bone augmentation was clearly recognized up to 8 weeks after transplantation, as were upregulation of VEGFs and BMP4 expressions at the early stages of transplantation. Thus, GAM-based miR delivery may provide an alternative non-viral approach by improving transgene efficacy via a small sequence that can regulate the multiple pathways.

Clinical and Radiological Clues of Traumatic Craniocervical Junction Injuries Requiring Occipitocervical Fusion to Early Diagnosis.

OBJECTIVE: The purpose of this study is to find the clinical and radiographic characteristics of traumatic craniocervical junction (CCJ) injuries requiring occipitocervical fusion (OC fusion) for early diagnosis and surgical intervention. METHODS: We retrospectively reviewed 12 patients with CCJ injuries presenting to St. Michaels Hospital in Toronto who underwent OC fusion and looked into the following variables; (1) initial trauma data on emergency room arrival, (2) associated injuries, (3) imaging characteristics of computed tomography (CT) scan and magnetic resonance imaging (MRI), (4) surgical procedures, surgical complications, and neurological outcome. RESULTS: All patients were treated as acute spinal injuries and underwent OC fusion on an emergency basis. Patients consisted of 10 males and 2 females with an average age of 47 years (range, 18-82 years). All patients sustained high-energy injuries. Three patients out of 6 patients with normal BAI (basion-axial interval) and BDI (basion-dens interval) values showed visible CCJ injuries on CT scans. However, the remaining 3 patients had no clear evidence of occipitoatlantal instability on CT scans. MRI clearly described several findings indicating occipitoatlantal instability. The 8 patients with normal values of ADI (atlantodens interval interval) demonstrated atlantoaxial instability on CT scan, however, all MRI more clearly and reliably demonstrated C1/2 facet injury and/or cruciate ligament injury. CONCLUSION: We advocate measures to help recognize CCJ injury at an early stage in the present study. Occipitoatlantal instability needs to be carefully investigated on MRI in addition to CT scan with special attention to facet joint and ligament integrity.

Postoperative Cervicothoracic Kyphosis Following Infantile Intramedullary Tumor Resection Accelerates Neurological Deterioration.

Intramedullary spinal cord tumors are rare in children. Regardless of the type of tumor, surgical removal is thought to improve progression-free survival. However, postoperative kyphosis is a serious problem in children, who can expect long-term survival. We present a pediatric case of neurofibromatosis type 2-related spinal ependymoma at the cervicothoracic regions where acute neurological deterioration was developed due to a combination of tumor recurrence and postoperative kyphotic deformity. In the first surgery, subtotal tumor resection was performed via osteoplastic laminotomy. Postoperative radiological evaluation at several months showed cervicothoracic junctional kyphosis, which subsequently made a significant improvement by lifestyle instructions. However, 22 months after the surgery, he exhibited rapid neurological deterioration caused by the regrowth of the recurrent tumor and re-emergence of kyphotic deformity, which led to the fixed laminar flap sank into the spinal canal. Therefore, a second surgery was performed 23 months after the first surgery, and gross total removal was achieved. Osteoplastic laminotomy is presumed to reduce the occurrence of postoperative kyphosis compared with laminectomy, but there have been no reports on the spinal cord compression by plunging of the re-fixed laminar flap into the spinal canal. The kyphosis deformity increases the chance of re-fixed laminar flap coming off, thereby accelerating neurological injury on top of the neural damage by tumor recurrence itself. Therefore, pediatric patients with spinal cord tumors should be carefully managed in terms of recurrent tumors and postoperative kyphosis, and timely surgical intervention is necessary before kyphotic deformity becomes evident.