Spine Surgery – from Basics to Advances Technology

Background: We aimed to analyze the clinical outcomes and effectiveness of cervical biportal endoscopic spine surgery (C-BESS) and anterior cervical discectomy and fusion (ACDF) in patients with symptomatic cervical disc herniation. Methods: This study was a retrospective chart review of four-year clinical data involving 318 cases of symptomatic cervical disc herniation, with 156 patients undergoing the ACDF and 162 patients receiving the C-BESS. Preoperative and postoperative one-year data were collected. Results: The numeric rating scale and neck disability index showed statistically significant improvement for both ACDF and C-BESS groups. While showing a longer operation time and more blood loss during surgery compared to the ACDF group, the C-BESS group demonstrated a learning effect as the surgeon’s proficiency increased with more cases. There was no significant difference in the postoperative length of hospitalization between the two methods. The subgroup with predominant arm pain revealed the statistical difference in arm pain intensity changes between the two groups (p < 0.001). The rates of complication were 2.6% for the ACDF group and 1.9% for the C-BESS group. Conclusions: C-BESS and ACDF are effective surgical treatments for patients with symptomatic single-level cervical disc herniation in relieving relevant pain intensities and pain-related disabilities. Full article

Introduction: A practical solution to the incidental unreliability of intraoperative neuromonitoring (IONM) may be the simultaneous neurophysiological recording and control of the surgical field through a camera (the concept of “Real-time” IONM). During “Real-time” IONM, the surgeon is immediately warned about the possibility of damage to the neural structures during, but not after, standard idiopathic scoliosis (IS) corrective surgery procedures (the concept of “Surgeon–neurophysiologist” interactive, verbal IONM). This study aimed to compare the advantages, utilities, reliabilities, and time consumption of the two IONM scenarios. Methods: Studies were performed in two similar groups of patients undergoing surgery primarily due to Lenke 2 idiopathic scoliosis (N = 120), when both IONM approaches were applied. Neurophysiological evaluations of the spinal transmission were performed pre- (T0), intra- (before (T1) and after (T2) surgery), and postoperatively (T3), as well as once in healthy volunteers (control, N = 60). Non-invasive and innovative recordings of the motor evoked potentials (MEPs) bilaterally from the peroneal (PER) nerve and tibialis anterior (TA) muscle were performed with surface electrodes as a result of transcranial magnetic stimulation (TMS) or electrical stimulation (TES) at T0–T3. Results: In both groups, the MEP amplitudes and latencies recorded from the PER nerve were approximately 67% lower and 3.1 ms shorter than those recorded from the TA muscle. The MEP recording parameters differed similarly at T0–T3 compared to the control group. In all patients, the MEP parameters induced by TMS (T0) and TES (T1) did not differ. The MEP amplitude parameters recorded from the TA and PER at T1 and T2 indicated a bilateral improvement in the neural spinal conduction due to the surgical intervention. The TMS-induced MEP amplitude at T3 further increased bilaterally. In both IONM groups, an average 51.8 BIS level of anesthesia did not affect the variability in the MEP amplitude, especially in the PER recordings when the applied TES strength was 98.2 mA. The number of fluctuations in the MEP parameters was closely related to the number of warnings from the neurophysiologist during the transpedicular screw implantation, corrective rod implantation, and distraction, derotation, and compression procedures, and it was higher in the “Surgeon–neurophysiologist” IONM group. The average duration of surgery was shorter by approximately one hour in the “Real-time” IONM group. The number of two-way communications between the surgeon and the neurophysiologist and vice versa in the “Real-time” IONM group decreased by approximately half. Conclusions: This study proves the superiority of using “Real-time” IONM over the standard “Surgeon–neurophysiologist” IONM procedure in increasing the safety and non-invasiveness, shortening the time, and lowering the costs of the surgical treatment of IS patients. The modifications of the MEP nerve-conduction-recording technology with surface electrodes from nerves enable precise and reliable information on the pediatric patient’s neurological condition at every stage of the applied surgical procedures, even under conditions of slight fluctuations in anesthesia. Full article

Background incidence of pyogenic spinal infections has increased in recent years. In addition to treating the spinal infection, optimal care also includes identifying the source of the pyogenic spinal infection and the presence of other infections. The aim of this study is to elucidate the prevalence of oral cavity infection (OCI) within this patient cohort. Methods As part of a prospective study conducted from 2016 to 2021, the number of patients with dental infections was investigated by means of an orthopantomogram (OPG) and subsequent dental examination. Results The presence of an oral infection was investigated in 55 (47%) of 118 patients by an OPG, 29 (53%) of whom had a corresponding abnormality of the oral cavity. In addition to the spinal infection, patients with an oral cavity infection revealed an increased incidence of endocarditis, sepsis and brain abscess. A spinal epidural abscess, a multilevel affection of the infection, and an elevated CRP value were also found in patients with a co-existing oral cavity infection. Back pain assessed at admission and 3 months after surgery was also more pronounced in patients with an oral cavity infection. Neurological deficits were often present in patients with spinal and oral cavity infection. Conclusions The presence of an oral cavity infection has proven to be one of the important factors in the detection of the source of the pyogenic spinal infection. In addition, a pronounced spinal affection and frequent co-infections were seen in patients with an oral cavity infection. Full article

Background: Access to blood products is crucial for patient safety during the perioperative course. However, reduced donations and seasonally occurring blood shortages pose a significant challenge to the healthcare system, with surgeries being postponed. The German Blood Transfusion act requires that RBC packages become assigned to an individual patient, resulting in a significant reduction in the available blood products, further aggravating shortages. We aimed to develop a scoring system predicting transfusion probability in patients undergoing spine surgery to reduce assignment and, thus, increase the availability of blood products. Methods: The medical records of 252 patients who underwent spine surgery were evaluated and 18 potential predictors for RBC transfusion were tested to construct a logistic-regression-based predictive scoring system for blood transfusion in patients undergoing spine surgery. Results: The variables found to be the most important included the type of surgery, vertebral body replacement, number of stages, and pre-operative Hb concentration, indicating that surgical specification and the extent of the surgical procedure were more influential than the pre-existing patient condition and medication. Conclusions: Our model showed a good discrimination ability with an average AUC [min, max] of 0.87 [0.6, 0.97] and internal validation with a similar AUC of 0.84 [0.66, 0.97]. In summary, we developed a scoring system to forecast patients’ perioperative transfusion needs when undergoing spine surgery using pre-operative predictors, potentially reducing the need for RBC allocation and, thus, resulting in an increased availability of this valuable resource. Full article

Diagnosing cervical foraminal stenosis with intermittent arm radiculopathy is challenging due to discrepancies between MRI findings and symptoms. This can be attributed to the fact that MRI images are often obtained in a relaxed supine position. This study aims to evaluate the feasibility of the Dynamic MRI Compression System (DMRICS) and to assess possible changes in cervical foramina, with both quantitative measurements and qualitative grading systems, with MRI during a simulated Spurling test. Ten patients (five women and five men, ages 29–45) with previously confirmed cervical foraminal stenosis underwent MRI scans using DMRICS. MRI images were acquired in both relaxed and provoked states. A radiologist assessed 30 foramina (C4–C7) on the symptomatic side in both patient positions. Quantitative and qualitative measures were performed, including the numeric rating scale (NRS) and the Park and Kim grading systems. The provoked state induced concordant neck and arm pain in 9 of 10 patients. Significant shifts in Park and Kim foraminal gradings were noted: 13 of 27 Park gradings and 9 of 27 Kim gradings escalated post provocation. No quantitative changes were observed. This pilot study indicates that the DMRICS device has the potential to improve diagnostic accuracy for cervical radiculopathy, demonstrating induced cervical foraminal changes during a simulated Spurling test while performing MRI. Full article

Background: Severe spinal curvatures (SSCs) in children and adolescents have long been treated with preoperative Halo traction, in its various variations. There are also several radical techniques available for the management of neglected SSCs, such as osteotomies; however, these can be risky. Comparing the treatment outcomes when using preoperative Halo Gravity Traction (HGT) against the use of a Magnetically Controlled Growing Rod (MCGR) as a temporary internal distraction (TID) device, we evaluated the differences in surgical and radiological outcomes. Methods: We conducted a retrospective study of 30 patients with SSCs, treated with HGT followed by posterior spinal fusion (PSF; Group 1, n = 18) or treated using a temporary MCGR as a TID followed by PSF (Group 2, n = 12). All patients underwent surgical treatment between 2016 and 2022. The inclusion criteria were SSC > 90°, flexibility < 30%, and the use of preoperative HGT followed by PSF or the two-stage surgical procedure with initial TID rod placement (Stage 1) followed by PSF (Stage 2). The evaluated parameters were as follows: rib hump, trunk height, and radiographic outcomes. All parameters were collected preoperatively, after the initial surgery, after final correction and fusion, and during the final follow-up. Results: In Group 1, we evaluated 18 patients with a mean age of 15.5 years; in Group 2, we evaluated 12 patients with a mean age of 14.2 years. The interval between the staged procedures averaged 32.7 days. The mean preoperative main curves (MC) were 118° and 112° in Group 1 and Group 2, respectively. After definitive surgery, the MC was corrected to 42° and 44° in G1 and G2, respectively. The mean percentage correction of the MC was similar in both groups (65% vs. 61% in G1 and G2, respectively). The mean preoperative thoracic kyphosis was 92.5° in G1 and 98° in G2, corrected to 43.8° in G1 and 38.8° in G2. Trunk height increased by 9 cm on average. Conclusions: There are no benefits in using a MCGR as a temporary internal distraction device in the management of neglected scoliosis in adolescents. Surgical treatment of severe scoliosis may be safe, with a reduced risk of potential complications, when using preoperative HGT. A specific intraoperative complication when using a MCGR as a temporary internal distraction device was a 50% risk of transient neuromonitoring changes, due to significant force applied to the spine and radical distraction of the spine. We achieved similar clinical, radiographic, and pulmonary function outcomes for both techniques. The use of HGT causes less blood loss with a shorter overall time under anesthesia. Partial correction significantly aids the subsequent operation by facilitating a gradual reduction in the curvature, thereby reducing the difficulty of surgical treatment and the risk of neurological deficits. Full article

A CaO-SiO₂-P₂O₅-B₂O₃ bioactive glass-ceramic (BGS-7) spacer provides high mechanical stability, produces a chemical bond to the adjacent endplate, and facilitates fusion after spine surgery. This prospective, randomized, single-blind, non-inferiority trial aimed to evaluate the radiographic outcomes and clinical efficacy of anterior cervical discectomy and fusion (ACDF) using a BGS-7 spacer for treating cervical degenerative disorders. Thirty-six patients underwent ACDF using a BGS-7 spacer (Group N), and 40 patients underwent ACDF using polyetheretherketone (PEEK) cages filled with a mixture of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) for the treatment of cervical degenerative disorders. The spinal fusion rate was assessed 12 months postoperatively using three-dimensional computed tomography (CT) and dynamic radiographs. Clinical outcomes included patient-reported outcome measures, visual analog scale scores for neck and arm pain, and scores from the neck disability index (NDI), European Quality of Life-5 Dimensions (EQ-5D), and 12-item Short Form Survey (SF-12v2). All participants were randomly assigned to undergo ACDF using either a BGS-7 spacer or PEEK cage filled with HA and β-TCP. The primary outcome was the fusion rate on CT scan image at 12 months after ACDF surgery based on a per-protocol strategy. Clinical outcomes and adverse events were also assessed. The 12-month fusion rates for the BGS-7 and PEEK groups based on CT scans were 81.8% and 74.4%, respectively, while those based on dynamic radiographs were 78.1% and 73.7%, respectively, with no significant difference between the groups. There were no significant differences in the clinical outcomes between the two groups. Neck pain, arm pain, NDI, EQ-5D, and SF-12v2 scores significantly improved postoperatively, with no significant differences between the groups. No adverse events were observed in either group. In ACDF surgery, the BGS-7 spacer showed similar fusion rates and clinical outcomes as PEEK cages filled with HA and β-TCP. Full article

Background: The current method of treatment of spinal deformities would be almost impossible without pedicle screws (PS) placement. There are only a few studies evaluating the safety of PS placement and possible complications in children during growth. The present study was carried out to evaluate the safety and accuracy of PS placement in children with spinal deformities at any age using postoperative computed tomography (CT) scans. Methods: 318 patients (34 males and 284 females) who underwent 6358 PS fixations for pediatric spinal deformities were enrolled in this multi-center study. The patients were divided into three age groups: less than 10 years old, 11–13 years old, and 14–18 years old. These patients underwent postoperative CT scans and were analyzed for pedicle screw malposition (anterior, superior, inferior, medial, and lateral breaches). Results: The breach rate was 5.92% for all pedicles. There were 1.47% lateral and 3.12% medial breaches for all pedicles with tapping canals, and 2.66% lateral and 3.84% medial breaches for all pedicles without a tapping canal for the screw. Of the 6358 screws placed in the thoracic, lumbar, and sacral spine, 98% of the screws were accurately placed (grade 0, 1, and juxta pedicular). A total of 56 screws (0.88%) breached more than 4 mm (grade 3), and 17 (0.26%) screws were replaced. No new and permanent neurological, vascular, or visceral complications were encountered. Conclusions: The free-hand technique for pedicle screw placement in the acceptable and safety zone in pedicles and vertebral bodies was 98%. No complications associated with screw insertion in growth were noted. The free-hand technique for pedicle screw placement can be safely used in patients at any age. The screw accuracy does not depend on the child’s age nor the size of the deformity curve. Segmental instrumentation with posterior fixation in children with spinal deformities can be performed with a very low complication rate. Navigation of the robot is only an auxiliary tool in the hands of the surgeons, and the result of the work ultimately depends on the surgeons. Full article

Background: This ex vivo experimental study sought to compare screw planning accuracy of a self-derived deep-learning-based (DL) and a commercial atlas-based (ATL) tool and to assess robustness towards pathologic spinal anatomy. Methods: From a consecutive registry, 50 cases (256 screws in L1-L5) were randomly selected for experimental planning. Reference screws were manually planned by two independent raters. Additional planning sets were created using the automatic DL and ATL tools. Using Python, automatic planning was compared to the reference in 3D space by calculating minimal absolute distances (MAD) for screw head and tip points (mm) and angular deviation (degree). Results were evaluated for interrater variability of reference screws. Robustness was evaluated in subgroups stratified for alteration of spinal anatomy. Results: Planning was successful in all 256 screws using DL and in 208/256 (81%) using ATL. MAD to the reference for head and tip points and angular deviation was 3.93 ± 2.08 mm, 3.49 ± 1.80 mm and 4.46 ± 2.86° for DL and 7.77 ± 3.65 mm, 7.81 ± 4.75 mm and 6.70 ± 3.53° for ATL, respectively. Corresponding interrater variance for reference screws was 4.89 ± 2.04 mm, 4.36 ± 2.25 mm and 5.27 ± 3.20°, respectively. Planning accuracy was comparable to the manual reference for DL, while ATL produced significantly inferior results (p < 0.0001). DL was robust to altered spinal anatomy while planning failure was pronounced for ATL in 28/82 screws (34%) in the subgroup with severely altered spinal anatomy and alignment (p < 0.0001). Conclusions: Deep learning appears to be a promising approach to reliable automated screw planning, coping well with anatomic variations of the spine that severely limit the accuracy of ATL systems. Full article

Minimization of the surgical approaches to spinal extradural metastases resection and stabilization was advocated by the 2012 Oncological Guidelines for Spinal Metastases Management. Minimally invasive approaches to spine oncology surgery (MISS) are continually advancing. This paper will describe the evolution of minimally invasive surgical techniques for the resection of metastatic spinal lesions and stabilization in a single institute. A retrospective analysis of patients who underwent minimally invasive extradural spinal metastases resection during the years 2013–2019 by a single surgeon was performed. Medical records, imaging studies, operative reports, rates of screw misplacement, operative time and estimated blood loss were reviewed. Detailed description of the surgical technique is provided. Of 138 patients operated for extradural spinal tumors during the study years, 19 patients were treated in a minimally invasive approach and met the inclusion criteria for this study. The mortality rate was significantly improved over the years with accordance of improve selection criteria to better prognosis patients. The surgical technique has evolved over the study years from fluoroscopy to intraoperative 3D imaging and navigation guidance and from k-wire screw insertion technique to one-step screws. Minimally invasive spinal tumor surgery is an evolving technique. The adoption of assistive devices such as intraoperative 3D imaging and one-step screw insertion systems was safe and efficient. Oncologic patients may particularly benefit from the minimization of surgical decompression and fusion in light of the frailty of this population and the mitigated postoperative outcomes associated with MIS oncological procedures. Full article

Objective: Examine Schober test’s (ST), Modified ST (MST), and Modified–Modified ST (MMST) surface markers’ accuracy in spanning lumbar L1-S1 motion segments and repeatability related to actual patient anatomy as measured on sagittal CT scans. Methods: The study included 25 patients of varying heights, weights, and gender without prior spinal surgery or deformity. Researchers assessed patients’ CT scans for ST, MST, and MMST skin levels of the measured cephalic and caudal endpoints. Results: The original ST failed to include at least one lumbar motion segment in all patients, omitting the L1-L2 motion segment in 17 patients and the L2-L3 in another eight. The additional cephalic length of the MST did not improve the inclusion of the actual L1-S1 components. The MMST measured 19 ‘patients’ entire L1-S1 motion segments, reaching a 76% accuracy rate. WMST, measuring 16 cm (instead of MMST’s 15 cm), improved the measurement significantly, measuring the L1-S1 motion segments in all cases (with 100% accuracy). Conclusion: ST and its modifications fail to span the L1-S1 motion segments and are thus prone to underestimating lumbar spine motion. This study shows that the WMST is much more accurate than previous modifications and is a better tool for evaluating lumbar spine motion. Full article

Background: This study investigates the efficacy of the Cervical Endoscopic Unilateral Laminoforaminotomy for Bilateral Decompression (CE-ULFBD) technique in treating cervical myeloradiculopathy, primarily caused by degenerative spondylosis. Traditionally managed through multisegmental anterior cervical discectomy and fusion (ACDF) or laminoplasty combined with foraminotomy, this condition has recently experienced a promising shift towards minimally invasive approaches, particularly endoscopic spinal decompression. While empirical evidence is still emerging, these techniques show potential for effective treatment. Method: The objective was to evaluate the outcomes of CE-ULFBD in achieving single or multilevel bilateral foraminal and central decompression, emphasizing the reduction of injury to posterior cervical muscles and the associated postoperative neck soreness common in conventional procedures. This paper delineates the surgical procedures involved in CE-ULFBD and presents the clinical outcomes of nine patients diagnosed with myeloradiculopathy due to severe cervical stenosis. Result: Assessments were conducted using the Visual Analogue Scale (VAS) for neck and arm pain and the Modified Japanese Orthopaedic Association scale (mJOA) for the activity measurement of daily living. Results indicated a considerable decrease in pain levels according to the VAS, coupled with significant improvements in functional capacities as measured by the mJOA scale. Additionally, no major postoperative complications were noted during the follow-up period. Conclusion: The study concludes that CE-ULFBD is a safe and effective approach for the treatment of cervical myeloradiculopathy resulting from severe cervical stenosis, offering a viable and less invasive alternative to traditional decompressive surgeries. Full article

Background: This research paper provides a systematic literature review (SLR) on the current status of augmented-reality head-mounted devices (AR-HMDs) that guide and navigate spine surgeries and pedicle screw placement. Methods: Embase, Scopus, PubMed, Cochrane Library and IEEE Xplore databases were screened for the systematic literature search to collect and statistically analyze live patient clinical, procedural and user experience data. Multi-level Poisson and binominal models were used for analysis. Results: In vivo patient data, only the clinically widely used Gertzbein–Robbins Scale, were published as an outcome in the recent heterogeneous literature. The statistical analysis supports the hypothesis that using AR-HMDs has the same clinical outcomes as using more expensive robot-assisted surgical (RAS) systems. Conclusions: AR-HMD-guided pedicle screw insertion is reaching its technology readiness, providing similar benefits to RAS. Further meta-analysis is expected in the future from higher case-numbered and standardized randomized clinical trials. Full article