Artificial intelligence (AI) is a field of computer science that equips machines with human-like intelligence and enables them to learn, reason, and solve problems when presented with data in various formats. Neurosurgery is often at the forefront of innovative and disruptive technologies, which have similarly altered the course of acute and chronic diseases. In diagnostic imaging, such as X-rays, computed tomography, and magnetic resonance imaging, AI is used to analyze images. The use of robots in the field of neurosurgery is also increasing. In neurointensive care units, AI is used to analyze data and provide care to critically ill patients. Moreover, AI can be used to predict a patient’s prognosis. Several AI applications have already been introduced in the field of neurosurgery, and many more are expected in the near future. Ultimately, it is our responsibility to keep pace with this evolution to provide meaningful outcomes and personalize each patient’s care. Rather than blindly relying on AI in the future, neurosurgeons should gain a thorough understanding of it and use it to enhance their patient care.

Purpose: The purpose of this retrospective study was to evaluate radiological and clinical outcomes in patients undergoing cervical disc arthroplasty (CDA) for cervical degenerative disc disease. The results may assist in surgical decision-making and enable more effective and safer implementation of cervical arthroplasty. Materials and Methods: A total of 125 patients who were treated with CDA between 2006 and 2019 were assessed. Radiological measurements and clinical outcomes included the visual analogue scale (VAS), the Neck Disability Index (NDI), and the Japanese Orthopaedic Association (JOA) myelopathy score assessment preoperatively and at ≥2 years of follow-up. Results: The mean follow-up period was 38 months (range, 25–114 months). Radiographic data demonstrated mobility at both the index and adjacent levels, with no signs of hypermobility at an adjacent level. There was a non-significant loss of cervical global motion and range of motion (ROM) of the functional spinal unit at the operated level, as well as the upper and lower adjacent disc levels, compared to preoperative status. The cervical global and segmental angle significantly increased. Postoperative neck VAS, NDI, and JOA scores showed meaningful improvements after one- and two-level CDA. We experienced a 29.60% incidence of heterotrophic ossification and a 3.20% reoperation rate due to cervical instability, implant subsidence, or osteolysis. Conclusion CDA is an effective surgical technique for optimizing clinical outcomes and radiological results. In particular, the preservation of cervical ROM with an artificial prosthesis at adjacent and index levels and improvement in cervical global alignment could reduce revision rates due to adjacent segment degeneration.

Purpose: With an increasing number of anterior cervical discectomy and fusion (ACDF) being conducted for degenerative cervical disc disease, there is a rising interest in the related quality of management and healthcare costs. Unplanned readmission after ACDF affects both the quality of management and medical expenses. This meta-analysis was performed to evaluate the risk factors of unplanned readmission after ACDF to improve the quality of management and prevent increase in healthcare costs. Materials and Methods: We searched the databases of PubMed, EMBASE, Web of Science, and Cochrane Library to identify eligible studies using the searching terms, “readmission” and “ACDF.” A total of 10 studies were included. Results: Among the demographic risk factors, older age [weighted mean difference (WMD), 3.93; 95% confidence interval (CI), 2.30–5.56; p<0.001], male [odds ratio (OR), 1.23; 95% CI, 1.10–1.36; p<0.001], and private insurance (OR, 0.34; 95% CI, 0.17–0.69;p<0.001) were significantly associated with unplanned readmission. Among patient characteristics, hypertension (HTN) (OR, 2.14; 95% CI, 1.41–3.25; p<0.001), diabetes mellitus (DM) (OR, 1.59; 95% CI, 1.20–2.11; p=0.001), coronary artery disease (CAD) (OR, 2.87; 95% CI, 2.13–3.86; p<0.001), American Society of Anesthesiologists (ASA) physical status grade >2 (OR, 2.13; 95% CI, 1.68–2.72; p<0.001), and anxiety and depression (OR, 1.39; 95% CI, 1.29–1.51; p<0.001) were significantly associated with unplanned readmission. Among the perioperative factors, pulmonary complications (OR, 22.52; 95% CI, 7.21–70.41; p<0.001) was significantly associated with unplanned readmission. Conclusion Male, older age, HTN, DM, CAD, ASA grade >2, anxiety and depression, pulmonary complications were significantly associated with an increased occurrence of unplanned readmission after ACDF.

Purpose: Giant cell tumors (GCTs) are common benign primary bone tumors and are well known for their locally aggressive performance and tendency to recur. The purpose of this study was to analyze the effects of denosumab and risk factors for recurrent spinal GCTs. Materials and Methods: We searched PubMed, EMBASE, Web of Science, and Cochrane Library databases to identify differences between individuals treated with and without denosumab and risk factors for spinal GCT recurrence. Patient data, including age, sex, tumor resection range, location, denosumab use, Campanacci grade, and radiotherapy, were documented. Comparable factors were evaluated using odds ratios (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs). Results: Sixteen studies were included. The overall incidence of spinal GCT recurrence was 29%. Campanacci grade III tumors showed better recurrence outcomes than grades I and II (OR, 16.36; 95% CI, 4.19–63.93; p<0.001). Gross total resection (OR, 0.09;95% CI, 0.04–0.19; p<0.001), radiotherapy (OR, 0.27; 95% CI, 0.11–0.65; p=0.004), and the use of denosumab during subtotal resection (OR, 2.95; 95% CI, 1.07–8.17; p=0.04) were important factors for reducing recurrence. Conclusion Clinicians must consider the effects of gross total resection, radiotherapy use, and denosumab use in cases of subtotal resection during spinal GCT treatment. So far, many researchers have used denosumab in spinal GCT, but none have clearly suggested an endpoint. Most studies, however, recommend using it for more than 6 months.

Objective: : Cervical surgery in patients with cervical spondylotic myelopathy (CSM) and cerebral palsy (CP) is challenging owing to the complexities of the deformity. We assessed factors affecting postoperative complications and outcomes after CSM surgery in patients with CP. Methods: : Thirty-five consecutive patients with CP and CSM who underwent cervical operations between January 2006 and January 2014 were matched to 35 non-cerebral palsy (NCP) control patients. Postoperative complications and radiologic outcomes were compared between the groups. In the CP group, the Japanese Orthopaedic Association score; Oswestry neck disability index; modified Barthel index; and values for the grip and pinch, Box and Block, and Jebsen-Taylor hand function tests were obtained preand postoperatively and compared between those with and without postoperative complications. Results: : Sixteen patients (16/35%) in the CP group and seven (7/35%) in the NCP group (p=0.021) had postoperative complications. Adjacent segment degeneration (p=0.021), postoperative motor weakness (p=0.037), and revisions (p=0.003) were significantly more frequent in the CP group than in the NCP group; however, instrument-related complications were not significantly higher in the CP group (7/35 vs. 5/35, p=0.280). The number of preoperative fixed cervical deformities were significantly higher in CP with postoperative complications (5/16 vs. 1/19, p=0.037). In the CP group, clinical outcomes were almost similar between those with and without postoperative complications. Conclusion : The occurrence of complications during the follow-up period was high in patients with CP. However, postoperative complications did not significantly affect clinical outcomes.

Objective: : Cervical surgery in patients with cervical spondylotic myelopathy (CSM) and cerebral palsy (CP) is challenging owing to the complexities of the deformity. We assessed factors affecting postoperative complications and outcomes after CSM surgery in patients with CP. Methods: : Thirty-five consecutive patients with CP and CSM who underwent cervical operations between January 2006 and January 2014 were matched to 35 non-cerebral palsy (NCP) control patients. Postoperative complications and radiologic outcomes were compared between the groups. In the CP group, the Japanese Orthopaedic Association score; Oswestry neck disability index; modified Barthel index; and values for the grip and pinch, Box and Block, and Jebsen-Taylor hand function tests were obtained preand postoperatively and compared between those with and without postoperative complications. Results: : Sixteen patients (16/35%) in the CP group and seven (7/35%) in the NCP group (p=0.021) had postoperative complications. Adjacent segment degeneration (p=0.021), postoperative motor weakness (p=0.037), and revisions (p=0.003) were significantly more frequent in the CP group than in the NCP group; however, instrument-related complications were not significantly higher in the CP group (7/35 vs. 5/35, p=0.280). The number of preoperative fixed cervical deformities were significantly higher in CP with postoperative complications (5/16 vs. 1/19, p=0.037). In the CP group, clinical outcomes were almost similar between those with and without postoperative complications. Conclusion : The occurrence of complications during the follow-up period was high in patients with CP. However, postoperative complications did not significantly affect clinical outcomes.

Purpose: This study aimed to present our experiences with a precise surgical strategy for sacrectomy. Materials and Methods: This study comprised a retrospective review of 16 patients (6 males and 10 females) who underwent sacrectomy from 2011 to 2019. The average age was 42.4 years old, and the mean follow-up period was 40.8 months. Clinical data, including age, sex, history, pathology, radiographs, surgical approaches, onset of recurrence, and prognosis, were analyzed. Results: The main preoperative symptom was non-specific local pain. Nine patients (56%) complained of bladder and bowel symptoms. All patients required spinopelvic reconstruction after sacrectomy. Three patients, one high, one middle, and one hemisacrectomy, underwent spinopelvic reconstruction. The pathology findings of tumors varied (chordoma, n=7; nerve sheath tumor, n=4; giant cell tumor, n=3, etc.). Adjuvant radiotherapy was performed for 5 patients, chemotherapy for three, and combined chemoradiotherapy for another three. Six patients (38%) reported postoperative motor weakness, and newly postoperative bladder and bowel symptoms occurred in 5 patients. Three patients (12%) experienced recurrence and expired. Conclusion In surgical resection of sacral tumors, the surgical approach depends on the size, location, extension, and pathology of the tumors. The recommended treatment option for sacral tumors is to remove as much of the tumor as possible. The level of root sacrifice is a predicting factor for postoperative neurologic functional impairment and the potential for morbidity. Pre-operative angiography and embolization are recommended to prevent excessive bleeding during surgery. Spinopelvic reconstruction must be considered following a total or high sacrectomy or sacroiliac joint removal.

Purpose: This study aimed to present our experience with failures in C-TDR and revision surgery outcomes. Materials and Methods: We retrospectively examined patients who underwent revision surgery due to the failure of C-TDR between May 2005 to March 2019. Thirteen patients (8 males and 5 females) were included in this study. The mean age was 46.1 years (range: 22–61 years), and the average follow-up period was 19.5 months (range: 12–64 months). The outcome measures of pre- and post-operative neck and arm pain using a visual analogue scale (VAS) and functional impairment were assessed using a modified Japanese Orthopedic Association (JOA) scale and the Neck Disability Index (NDI). Results: The main complaints of patients were posterior neck pain (77%), radiculopathy (62%), and/or myelopathy (62%). The causes of failure of C-TDR were improper indications for the procedure, osteolysis and mobile implant use, inappropriate techniques, and postoperative infection. The most common surgical level was C5–6, followed by C4–5. After revision surgery, the neck and arm pain VAS (preoperative vs. postoperative: 5.46 vs. 1.31; 4.86 vs. 1.08), a modified JOA scale (14.46 vs. 16.69), and the NDI (29.77 vs. 9.31) scores were much improved. Conclusion C-TDR is good surgical option. However, it is very important to adhere to strict surgical indications and contraindications to avoid failure of C-TDR. The results of reoperations were good regardless of the approach. Therefore, various reoperation options could be considered in patients with failed C-TDR.

Pelvic reconstruction after sacral resection is challenging in terms of anatomical complexity, excessive loadbearing, and wide defects. Nevertheless, the technological development of 3D-printed implants enables us to overcome these difficulties. Here, we present a case of sacral osteosarcoma surgically treated with hemisacrectomy and sacral reconstruction using a 3D-printed implant. The implant was printed as a customized titanium prosthesis from a 3D real-sized reconstruction of a patient's CT images. It consisted mostly of a porous mesh and incorporated a dense strut. After 3-months of neoadjuvant chemotherapy, the patient underwent hemisacretomy with preservation of contralateral sacral nerves. The implant was anatomically installed on the defect and fixed with a screw-rod system up to the level of L3. Postoperative pain was significantly low and the patient recovered sufficiently to walk as early as 2 weeks postoperatively. The patient showed left-side foot drop only, without loss of sphincter function. In 1-year follow-up CT, excellent bony fusion was noticed. To our knowledge, this is the first report of a case of hemisacral reconstruction using a custom-made 3D-printed implant. We believe that this technique can be applied to spinal reconstructions after a partial or complete spondylectomy in a wide variety of spinal diseases.
Drug Therapy ; Follow-Up Studies* ; Foot ; Humans ; Osteosarcoma* ; Pain, Postoperative ; Prostheses and Implants ; Sacrum ; Spinal Diseases ; Spinal Fusion ; Titanium ; Weight-Bearing

OBJECTIVE: Computed tomography (CT)-based method of three dimensional (3D) analysis (MIMICS®, Materialise, Leuven, Belgium) is reported as very useful software for evaluation of OPLL, but its reliability and reproducibility are obscure. This study was conducted to evaluate the accuracy of MIMICS® system, and inter- and intra-observer reliability in the measurement of OPLL. METHODS: Three neurosurgeons independently analyzed the randomly selected 10 OPLL cases with medical image processing software (MIMICS®) which create 3D model with Digital Imaging and Communication in Medicine (DICOM) data from CT images after brief explanation was given to examiners before the image construction steps. To assess the reliability of inter- and intra-examiner intraclass correlation coefficient (ICC), 3 examiners measured 4 parameters (volume, length, width, and length) in 10 cases 2 times with 1-week interval. RESULTS: The inter-examiner ICCs among 3 examiners were 0.996 (95% confidence interval [CI], 0.987–0.999) for volume measurement, 0.973 (95% CI, 0.907–0.978) for thickness, 0.969 (95% CI, 0.895–0.993) for width, and 0.995 (95% CI, 0.983–0.999) for length. The intra-examiner ICCs were 0.994 (range, 0.991–0.996) for volume, 0.996 (range, 0.944–0.998) for length, 0.930 (range, 0.873–0.947) for width, and 0.987 (range, 0.985–0.995) for length. CONCLUSION: The medical image processing software (MIMICS®) provided detailed quantification OPLL volume with minimal error of inter- and intra-observer reliability in the measurement of OPLL.
Longitudinal Ligaments* ; Methods ; Neurosurgeons ; Observer Variation*