C-Arm-Free Minimally Invasive Cervical Pedicle Screw Fixation (MICEPS): A Technical Note

A minimally invasive posterolateral approach designed to avoid the lateral misplacement of midcervical pedicle screws was reported, but there is no technical report that describes this technique without C-arm fluoroscopy. We report the results of a 2.5 years follow-up of a 62-year-old female patient with C4 metastatic breast cancer. The patient suffered from severe neck pain and impending quadriplegia for 2 months after radiation therapy. We performed C-arm-free minimally invasive cervical pedicle screw fixation (MICEPS). The patient was suc-cessfully treated with surgery, and her neck pain was well controlled. She had neither neurological deficits nor neck pain at the final (2.5-year) follow-up. C-arm-free MICEPS is a useful technique; in addition, the sur-geons and staff have no risk of radiation exposure, there is a reduced need for postoperative imaging, and a decreased revision rate can be expected with C-arm-free MICEPS

Transtubular Endoscopic Posterolateral Decompression of the L5 Root under Navigation and O-arm: A Technical Note

Among studies evaluating minimally invasive surgical (MIS) decompression of the L5 root, techniques involving transtubular endoscopic decompression under O-arm navigation are rare. We present the case of a 68-yearold woman with left leg pain, muscle weakness and gait disturbance of one month duration. The patient underwent transtubular endoscopic decompression under O-arm navigation. There is no radiation hazard to the operating room staff with this procedure. After surgery, the patient had significant pain relief and her left lower limb motor function had improved by follow-up at one year. C-arm-free endoscopic L5 root decompression is a safe and effective procedure

Mechanical Study of Various Pedicle Screw Systems including Percutaneous Pedicle Screw in Trauma Treatment

Background and Objectives: Spine surgery using a percutaneous pedicle screw placement (PPSP) is widely implemented for spinal trauma. However, percutaneous systems have been reported to have weak screw-rod connections. In this study, conventional open and percutaneous systems were biomechanically evaluated and compared. Material and Methods: The experiments were performed in two stages: the first stage was a break test, whereas the second stage was a fatigue test. Four systems were used for the experiments. System 1 was intended for conventional open surgery (titanium rod with a 6.0 mm diameter, using a clamp connecting mechanism). System 2 was a percutaneous pedicle screw (PPS) system for trauma (titanium alloy rod with a 6.0 mm diameter, using ball ring connections). System 3 was a PPS system for trauma (cobalt-chromium alloy rod with a 6.0 mm diameter, using sagittal adjusting screw connections). System 4 was a general-purpose PPS system (titanium alloy rod with a 5.5 mm diameter, using a mechanism where the adapter in the head holds down the screw). Results: Stiffness values of 54.8 N/mm, 43.1 N/mm, 90.9 N/mm, and 39.3 N/mm were reported for systems 1, 2, 3, and 4, respectively. The average number of load cycles in the fatigue test was 134,393, 40,980, 1,550,389, and 147,724 for systems 1 to 4, respectively. At the end of the test, the displacements were 0.2 mm, 16.9 mm, 1.2 mm, and 8.6 mm, respectively. System 1, with a locking mechanism, showed the least displacement at the end of the test. Conclusion: A few PPS systems showed better results in terms on stiffness and life than the open system. The experiments showed that mechanical strength varies depending on the spinal implant. The experiments conducted are essential and significant to provide the mechanical strength required for surgical reconstruction

Comparative Study of Bilateral Dual Sacral-Alar-Iliac Screws versus Bilateral Single Sacral-Alar-Iliac Screw for Adult Spine Deformities

Objective To evaluate the feasibility of O-arm navigation of bilateral dual sacral-alar-iliac (SAI) screws compared with conventional bilateral single SAI and S1 pedicle screws for pelvic anchors in cases of adult spinal deformity. Methods This retrospective, comparative study included 39 patients who underwent corrective fusion using SAI screws from T10 to the pelvis. Patients were divided into 2 groups according to the number of SAI screws placed during adult spinal deformity surgery: single SAI screw (group S, 17 cases) and dual SAI screws (group D, 22 cases). The incidence of rod breakage, proximal junctional kyphosis, screw loosening, reoperation, and global alignment in each group was estimated. Postoperative patient-reported outcomes were measured using the Oswestry Disability Index, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire, and visual analog scale. Results The incidence of SAI screw loosening was significantly lower in group D than in group S (23% vs. 65%, P = 0.011). The rod breakage incidence was 0% and 12% in groups D and S, respectively (P = 0.17). There were no significant differences in the postoperative global alignment and clinical outcomes between the 2 groups. Conclusions Dual SAI screws were associated with a significantly reduced incidence of screw loosening compared with single SAI screws. The bilateral dual SAI screws technique for pelvic anchors is feasible for the treatment of patients with adult spinal deformity

O-arm Navigation-Guided Surgical Resection and Posterior Fixation for a Large Sacral Schwannoma

Sacral schwannoma is a rare tumor with relatively few symptoms; it thus tends to be large at diagnosis and is challenging to treat surgically. We present the case of a 12-year-old girl with a large sacral schwannoma that was successfully surgically resected using O-arm navigation in a two-stage operation. First, we performed tumor resection from the posterior aspect with assisted O-arm navigation. One week later, resection from the anterior aspect was conducted with posterior spinopelvic fixation and fibula graft. We performed partial resection of the tumor from the anterior and posterior aspects as much as possible. O-arm navigation contributed to precise and safe tumor resection and implant insertion

Posterolateral Floating Technique for the Thoracic Ossification of the Posterior Longitudinal Ligament with Navigation: A Technical Note

We describe a floating technique via a posterolateral approach with intraoperative O-arm navigation to facilitate decompression of the spinal cord in thoracic myelopathy due to severe ossification of the posterior longitudinal ligament (OPLL). A 62-year-old man with myelopathy due to thoracic OPLL had left-leg muscle weakness, urinary disturbance, and spastic gait. Bilateral leg pain and gait disturbance had persisted for 2 years. He was successfully treated by the posterolateral OPLL floating procedure and posterior pedicle fixation under O-arm navigation. At a 2-year follow-up, manual muscle testing results and sensory function of the left leg had recovered fully. His cervical Japanese Orthopedic Association score had improved from 5/12 to 11/12. The novel intraoperative O-arm navigation-guided posterolateral floating procedure for thoracic OPLL is effective for achieving precise decompression and strong fixation with a posterior approach only and can provide an excellent result for severe thoracic OPLL without the risk of adverse events from intraoperative radiation

Long-Term Results of Posterior Vertebral Column Resection for Severe Thoracolumbar Kyphosis with Achondroplastic Patients: A Case Series

Background and Objectives: Thoracolumbar kyphosis is one of the most frequent skeletal manifestations in patients with achondroplasia. Few papers have been published on the surgical treatment of this condition, especially in skeletally mature patients. With this study, we presented a retrospective case series of long-term surgical results for achondroplastic patients with severe thoracolumbar kyphosis. This study was conducted to evaluate the outcome of surgical treatment for thoracolumbar kyphosis in patients associated with achondroplasia presenting with paraparesis. Materials and Methods: Three patients with achondroplasia who developed neurologic deficits due to severe thoracolumbar kyphosis and underwent surgical treatment were evaluated (mean age 22.3 years; mean follow-up 9.3 years). All patients were treated with posterior vertebral column resection (p-VCR) of hypoplastic apical vertebrae with a cage and segmental instrumentation. Neurologic outcomes (JOA scores), correction of kyphosis, and operative complications were assessed. Results: All patients had back pain, neurological deficits, and urinary disturbance before surgery. The average preoperative JOA score was 8.3/11 points, which was improved to 10.7/11 points at the final follow-up (mean recovery rate 83%). All patients obtained neurologic improvement after surgery. The mean preoperative kyphotic angle was 117 degrees (range 103 degrees-126 degrees). The postoperative angles averaged 37 degrees (range 14 degrees-57 degrees), resulting in a mean correction rate of 67%. All patients had postoperative complications such as rod breakage and/or surgical site infection. Conclusions: The long-term results of p-VCR were acceptable for treating thoracolumbar kyphosis in patients with achondroplasia. To perform this p-VCR safely, spinal navigation and neuromonitoring are inevitable when resecting non anatomical fused vertebrae and ensuring correct pedicle screw insertion. However, surgical complications such as rod breakage and surgical site infection may occur at a high rate, making informed consent very important when surgery is indicated

Liquid Biopsy Targeting Monocarboxylate Transporter 1 on the Surface Membrane of Tumor-Derived Extracellular Vesicles from Synovial Sarcoma

Simple Summary Synovial sarcoma (SS) is associated with a high risk of recurrence and poor prognosis, and no biomarker useful in monitoring tumor burden exists. We identified monocarboxylate transporter 1 (MCT1) expressed in extracellular vesicles (EVs) derived from synovial sarcoma as a potential such marker. Circulating levels of MCT1(+)CD9(+) EVs were significantly correlated with tumor volume in a SS mouse model. Serum levels of MCT1(+)CD9(+) EVs reflected tumor burden and treatment response in SS patients. Patients with MCT1 expression on the plasma membrane have significantly worse overall survival than those with nuclear expression. Silencing of MCT1 reduced the malignant phenotype including cellular viability, migration, and invasion of SS cells. MCT1 may thus be a promising novel target for liquid biopsies and a novel therapeutic target. The lack of noninvasive biomarkers that can be used for tumor monitoring is a major problem for soft-tissue sarcomas. Here we describe a sensitive analytical technique for tumor monitoring by detecting circulating extracellular vesicles (EVs) of patients with synovial sarcoma (SS). The proteomic analysis of purified EVs from SYO-1, HS-SY-II, and YaFuSS identified 199 common proteins. DAVID GO analysis identified monocarboxylate transporter 1 (MCT1) as a surface marker of SS-derived EVs, which was also highly expressed in SS patient-derived EVs compared with healthy individuals. MCT1(+)CD9(+) EVs were also detected from SS-bearing mice and their expression levels were significantly correlated with tumor volume (p = 0.003). Furthermore, serum levels of MCT1(+)CD9(+) EVs reflected tumor burden in SS patients. Immunohistochemistry revealed that MCT1 was positive in 96.7% of SS specimens and its expression on the cytoplasm/plasma membrane was significantly associated with worse overall survival (p = 0.002). Silencing of MCT1 reduced the cellular viability, and migration and invasion capability of SS cells. This work describes a new liquid biopsy technique to sensitively monitor SS using circulating MCT1(+)CD9(+) EVs and indicates the therapeutic potential of MCT1 in SS

Clinical relevance and functional significance of cell-free microRNA-1260b expression profiles in infiltrative myxofibrosarcoma

Infiltrative tumor growth into adjacent soft tissues is a major cause of the frequent recurrence and tumor-related death of myxofibrosarcoma (MFS), but no useful biomarkers reflecting tumor burden and infiltrative growth are available. While emerging evidence suggests a diagnostic and functional role of extracellular/circulating microRNA (miRNA) in various malignant diseases, their significance in MFS patients remains unknown. Global miRNA profiling identified four upregulated miRNAs in MFS patient sera and culture media of MFS cells. Among these, serum miR-1260b level was significantly upregulated in patient serum discriminating from healthy individuals and closely correlated with clinical status and tumor dynamics in MFS-bearing mice. In addition, high miR-1260b expression in serum was correlated with radiological tail-like patterns, characteristic of the infiltrative MFS. The extracellular miR-1260b was embedded in tumor-derived extracellular vesicles (EVs) and promoted cellular invasion of MFS through the downregulation of PCDH9 in the adjacent normal fibroblasts. Collectively, circulating miR-1260b expression may represent a novel diagnostic target for tumor monitoring of this highly aggressive sarcoma. Moreover, EV-miR-1260b could act as a transfer messenger to adjacent cells and mediate the infiltrative growth of MFS, providing new insights into the mechanism of infiltrative nature via crosstalk between tumor cells and their microenvironment