Clinical and radiological outcome of stand-alone percutaneous pedicle screw fixation (SAPF) versus minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). A propensity-matched cohort study.

In adult patients affected by degenerative disc disease with lumbar instability and chronic low back pain, spine surgery with lumbar fixation aims to reduce segmental instability and pain. Different techniques have been developed, but the optimal surgical technique remains controversial. No studies have compared the clinical and radiological outcomes between stand-alone pedicle screw fixation (SAPF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). This was a retrospective study. All patients who underwent surgery for single-level L4-L5 or L5-S1 lumbar stenosis, associated with minor lumbar instability and treated with SAPF or MI-TLIF techniques were included in the study. Data were collected preoperatively and at 24 monts follow-up. Clinical primary outcomes were Oswestry Disability Index (ODI) and Numerical Rating Scale (NRS). Secondary outcomes were patient satisfaction, walking ability and self reported back and leg pain. In addition, perioperative data and complications were recorded. Segmental lordosis (L4-L5 and L5-S1) and overall lumbar lordosis (L1-S1) were measured on lumbar X-Rays preoperatively and at least 24 months postoperatively. 277 patients were firstly identified. Baseline data and a minimum of two-year follow-up were available for 62 patients. After the propensity score matching, 44 patients (22 patients in the SAPF group and 22 patients in the MI-TLIF group) were matched. At 24 months follow-up, no difference between the two groups of patients in NRS (p = 0.11) and ODI scores (p = 0.21) were observed. Patients' satisfaction at follow-up was also not significantly different between the two groups. In both groups, a significant improvement in the walked distance was observed after surgery (p = 0.05) while no difference was observed regarding the type of surgery performed (p = 1.00). No differences were found in the pre- and post-operative median lumbar lordosis (p = 0.91 and p = 0.67) and the same findings were observed for lumbar segmental lordosis (p = 0.65 and p = 0.41 respectively). Significant improvements in ODI and NRS-scores were recorded after 24 months follow-up with both SAPF and MI-TLIF. No significant differences in postoperative PROMs and patients' satisfaction were observed between the groups. The results of our study indicate no superiority of either surgical technique concerning pain and functional outcomes after 24 months.

The efficacy of machine learning models in forecasting treatment failure in thoracolumbar burst fractures treated with short-segment posterior spinal fixation.

BACKGROUND: Although short-segment posterior spinal fixation (SSPSF) has shown promising clinical outcomes in thoracolumbar burst fractures, the treatment may be prone to a relatively high failure rate. This study aimed to assess the effectiveness of machine learning models (MLMs) in predicting factors associated with treatment failure in thoracolumbar burst fractures treated with SSPSF. METHODS: A retrospective review of 332 consecutive patients with traumatic thoracolumbar burst fractures who underwent SSPSF at our institution between May 2016 and May 2023 was conducted. Patients were categorized into two groups based on treatment outcome (failure or non-failure). Potential risk factors for treatment failure were compared between the groups. Four MLMs, including random forest (RF), logistic regression (LR), support vector machine (SVM), and k-nearest neighborhood (k-NN), were employed to predict treatment failure. Additionally, LR and RF models were used to assess factors associated with treatment failure. RESULTS: Of the 332 included patients, 61.4% were male (n = 204), and treatment failure was observed in 44 patients (13.3%). Logistic regression analysis identified Load Sharing Classification (LSC) score, lack of index level instrumentation, and interpedicular distance (IPD) as factors associated with treatment failure (P < 0.05). All models demonstrated satisfactory performance. RF exhibited the highest accuracy in predicting treatment failure (accuracy = 0.948), followed by SVM (0.933), k-NN (0.927), and LR (0.917). Moreover, the RF model outperformed other models in terms of sensitivity and specificity (sensitivity = 0.863, specificity = 0.959). The area under the curve (AUC) for RF, LR, SVM, and k-NN was 0.911, 0.823, 0.844, and 0.877, respectively. CONCLUSIONS: This study demonstrated the utility of machine learning models in predicting treatment failure in thoracolumbar burst fractures treated with SSPSF. The findings support the potential of MLMs to predict treatment failure in this patient population, offering valuable prognostic information for early intervention and cost savings.

The Minimally Invasive Bipolar Fixation for Pediatric Spinal Deformities: A Narrative Review.

Growing rod techniques are increasingly used for early-onset scoliosis in children. Unfortunately, they are associated with many complications, particularly neuromuscular scoliosis, favored by the poor general condition of these patients and the fragility of their osteoporotic bones. Furthermore, these interventions are often iterative and usually followed by vertebral fusion at the end of growth. This is a review of the literature on a recent fusionless technique, minimally invasive bipolar fixation, which is more stable than the traditional growing rod techniques and less aggressive than vertebral arthrodesis. It allows the avoidance of arthrodesis, owing to the solidity of the construct and the stability of the results, leading to progressive spinal stiffening that occurs over time. The results of this technique have been published with a long follow-up period and have confirmed that it can completely replace posterior vertebral arthrodesis, especially in the most complicated scoliosis. Because it preserves growth, this technique should be recommended for early-onset scoliosis before the age of 10 years. The use of a self-expanding rod can avoid the need for repeated surgery, thereby reducing the risk of complications and the overall cost of treatment.

Recurrence of kyphotic deformity following implant removal in pediatric pure discoligamentous Chance-type injury: A case report.

Pediatric pure discoligamentous Chance-type injury is relatively rare and the appropriate surgical method has not yet been established, particularly, whether spinal fixation with fusion or without fusion is more effective. This case report describes a 10-year-old-boy who sustained an L2-3 pure discoligamentous Chance-type injury following a car accident and underwent an L2-3 posterior fixation without fusion. The implants were removed after eight months of an uneventful postoperative course. However, four months later, the kyphotic deformity recurred. Although the deformity gradually progressed over nine months, the patient remained neurologically intact and asymptomatic. This report suggests that fixation without fusion may not be appropriate in pediatric patients with pure discoligamentous Chance-type injuries. Spinal fixation with fusion may be recommended to prevent loss of correction and ensure secure stabilization.

Percutaneous Functional Spinal Unit Cementoplasty versus Posterior Spinal Fixation with Vertebroplasty for Symptomatic Chronic Osteoporotic Vertebral Fractures: A Retrospective Study with a 2-Year Follow up.

PURPOSE: To compare the clinical efficacy of percutaneous functional spinal unit cementoplasty (PFSUP) and posterior spinal fixation combined with vertebroplasty (PSF + VP) for the treatment of symptomatic chronic osteoporotic vertebral fractures (SCOVFs). METHOD: Thirty-one patients with SCOVFs were included in this retrospective study and divided into PFSUP (n = 14) and PSF + VP (n = 17) groups. Visual analog scores (VAS) and Oswestry Disability Index (ODI) were recorded before and after surgery and at the last follow-up. Besides, the local kyphosis angle (LKA) and sagittal vertical axis (SVA) were measured. The operation duration, number of X-ray exposures, amount of blood loss, bed rest duration, hospitalization duration, and presence of complications were recorded. RESULT: The VAS, ODI, LKA, and SVA after surgery and at the last follow-up were significantly improved in both groups compared to preoperative measurements. The PFSUP group experienced shorter operation duration (78.2 ± 13.1 vs. 124.7 ± 14.7, p < 0.001), less blood loss (31.1 ± 8.1 vs. 334.7 ± 70.9, p < 0.001), more X-ray exposures (92.1 ± 14.3 vs. 29.4 ± 5.5, p < 0.001), shorter bed rest duration (12.4 ± 3.8 vs. 43.4 ± 10.0, p < 0.001), shorter hospitalization (6.6 ± 2.4 vs. 10.9 ± 2.7, p < 0.001), lower complication rate (28.5% vs. 64.7%, p < 0.05), and higher cement leakage rate (42.9% vs. 5.8%, p < 0.05) than the PSF + VP group. CONCLUSION: During the treatment of SCOVFs, the combination of PFSUP and PSF + VP can restore spinal stability, improve kyphosis, and relieve pain. PFSUP can reduce blood loss and complications, early mobilization, and shorten the hospital stay, but it is associated with a higher cement leakage rate and more radiation exposure.

Analysis of factors associated with the failure of treatment in thoracolumbar burst fractures treated with short-segment posterior spinal fixation.

BACKGROUND: The treatment of thoracolumbar burst fractures continues to pose challenges. Although short-segment posterior spinal fixation (SSPSF) has shown satisfactory clinical outcomes, it is accompanied by a relatively high rate of treatment failure. This study aimed to assess factors associated with treatment failure in thoracolumbar burst fractures treated with SSPSF. METHODS: The clinical data of 241 consecutive patients with a traumatic thoracolumbar burst fracture who underwent SSPSF at our center between Apr 2016 and Apr 2021 were retrospectively reviewed. Patients were divided into two groups (failure of the treatment group and non-failure of the treatment group). We compared potential risk factors for the failure of treatment including age, gender, body mass index, smoking, diabetes, vertebral body compression rate, use of crosslinks, percentage of anterior height compression, presence of index level instrumentation, Cobb angle, interpedicular distance (IPD), canal compromise, Load Sharing Classification (LSC) score, use of posterolateral fusion, and pain intensity between the two groups. RESULTS: A sum of 137 (56.8%) males and 104 (43.2%) females were enrolled where the mean age and follow-up of the participants were 48.34 ± 10.23 years and 18.67 ± 5.23 months, respectively. Treatment failure was observed in 34 cases (14.1%). The results of the binary logistic regression analysis revealed that the lack of index level instrumentation (OR 2.21; 95% CI 1.78-3.04; P = 0.014), LSC score (odds ratio [OR] 2.64; 95% confidence interval [95% CI], 1.34-3.77; P = 0.007), and IPD (OR 1.77; 95% CI 1.51-2.67; P = 0.023) were independently associated with a higher rate of failure of treatment. CONCLUSIONS: The findings of this study revealed that increased rates of treatment failure in thoracolumbar burst fractures treated with SSPSF were associated with factors such as the absence of index level instrumentation, higher LSC scores, and larger IPD. These findings could be helpful in the proper management of patients with unstable thoracolumbar burst fractures.

Comparing Cortical Bone Trajectory and Traditional Pedicle Screws in Transforaminal Lumbar Interbody Fusion: A Retrospective Cohort Study of One-Year Outcomes.

INTRODUCTION: This is a retrospective study of consecutive patients undergoing transforaminal lumbar interbody fusion (TLIF) at a single institution. The objective of this study was to compare the long-term results associated with cortical bone trajectory (CBT) and traditional pedicle screw (TPS) via posterolateral approach in TLIF. METHODS: Consecutive patients treated from November 2014 to March 2019 were included in the CBT TLIF group, while consecutive patients treated from October 2010 to August 2017 were included in the TPS TLIF group. Inclusion criteria comprised single-level or two-level TLIF for degenerative spondylolisthesis with stenosis and at least one year of clinical and radiographic follow-up. Variables of interest included pertinent preoperative, perioperative, and postoperative data. Non-parametric evaluation was performed using the Wilcoxon test. Fisher's exact test was used to assess group differences for nominal data. RESULTS: Overall, 140 patients met the inclusion criteria; 69 patients had CBT instrumentation (mean follow-up 526 days) and 71 patients underwent instrumentation placement via TPS (mean follow-up 825 days). Examination of perioperative and postoperative outcomes demonstrate comparable results between the groups with perioperative complications, length of stay, discharge destination, surgical revision rate, and fusion rates all being similar between groups (p = 0.1; p = 0.53; p = 0.091; p = 0.61; p = 0.665, respectively). CONCLUSIONS: CBT in the setting of TLIF offer equivalent outcomes to TPS with TLIF at both short- and long-term intervals of care.

Correlation Between Sagittal Balance and Mechanical Distal Junctional Failure in Degenerative Pathology of the Spine: A Retrospective Analysis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study aimed to investigate the failure of the caudal end of lumbar posterior fixation in terms of pre-operative and post-operative spinopelvic parameters, correction performed, demographic and clinical data. METHODS: The lumbar, thoraco-lumbar and lumbo-sacral posterior fixations performed with pedicle screws and rods in 2017-2019 were retrospectively analyzed. As 81% failures occurred within 4 years, an observational period of 4 years was chosen. The revision surgeries due to the failure in the caudal end were collected in the junctional group. Fixations which have not failed were gathered in the control group. The main spinopelvic parameters were measured for each patient on standing lateral radiographs with the software Surgimap. Demographic and clinical data were extracted for both groups. RESULTS: Among the 457 patients who met the inclusion criteria, the junctional group included 101 patients, who required a revision surgery. The control group collected 356 primary fixations. The two most common causes of revision surgeries were screws pullout (57 cases) and rod breakage (53 cases). SVA, PT, LL, PI-LL and TPA differed significantly between the two groups (P = .021 for LL, P < .0001 for all the others). The interaction between the two groups and the pre-operative and post-operative conditions was significant for PT, SS, LL, TK, PI-LL and TPA (P < .005). Sex and BMI did not affect the failure onset. CONCLUSIONS: Mechanical failure is more likely to occur in patients older than 40 years with a thoraco-lumbar fixation where PT, PI-LL and TPA were not properly restored.

Screw Osteointegration-Increasing Biomechanical Resistance to Pull-Out Effect.

Spinal disorders cover a broad spectrum of pathologies and are among the most prevalent medical conditions. The management of these health issues was noted to be increasingly based on surgical interventions. Spinal fixation devices are often employed to improve surgery outcomes, increasing spinal stability, restoring structural integrity, and ensuring functionality. However, most of the currently used fixation tools are fabricated from materials with very different mechanical properties to native bone that are prone to pull-out effects or fail over time, requiring revision procedures. Solutions to these problems presently exploited in practice include the optimal selection of screw shape and size, modification of insertion trajectory, and utilization of bone cement to reinforce fixation constructs. Nevertheless, none of these methods are without risks and limitations. An alternative option to increasing biomechanical resistance to the pull-out effect is to tackle bone regenerative capacity and focus on screw osteointegration properties. Osteointegration was reportedly enhanced through various optimization strategies, including use of novel materials, surface modification techniques (e.g., application of coatings and topological optimization), and utilization of composites that allow synergistic effects between constituents. In this context, this paper takes a comprehensive path, starting with a brief presentation of spinal fixation devices, moving further to observations on how the pull-out strength can be enhanced with existing methods, and further focusing on techniques for implant osteointegration improvement.

Spectral metal artifact reduction after posterior spinal fixation in photon-counting detector CT datasets.

PURPOSE: To investigate the usefulness of virtual monoenergetic image (VMI) reconstructions derived from scans on a novel photon-counting detector CT (PCD-CT) for artifact reduction in patients after posterior spinal fixation. METHODS: This retrospective cohort study included 23 patients status post posterior spinal fixation. Subjects were scanned on a novel PCD-CT (NAEOTOM Alpha, Siemens Healthineers, Erlangen, Germany) as part of routine clinical care. 14 sets of VMI reconstructions were derived in 10 keV increments for the interval 60-190 keV. The mean and the standard deviation (SD) of CT-values in 12 defined locations around a pair of pedicle screws on one vertebral level and the SD of homogenous fat were measured and used to calculate an artifact index (AIx). RESULTS: Averaged over all regions, the lowest AIx was observed at VMI levels of 110 keV (32.5 (27.8-37.9)) which was significantly different from those of VMIs ≤ 90 keV (p < 0.001) or ≥160 keV (p < 0.015), respectively. Overall AIx values increased in both lower- and higher-keV levels. Regarding individual locations, either a monotonous AIx-decrease for increasing keV values or an AIx-minimum in intermediate-keV levels (100-140 keV) was found. In locations adjacent to larger metal parts, the increase of AIx values at the high-end of the keV spectrum was mainly explained by a reappearance of streak artifacts. CONCLUSION: Our findings suggest that 110 keV is the optimal VMI setting for overall artifact suppression. In specific anatomical regions, however, slight adjustments towards higher-keV levels may provide better results.

Are modular pedicle screws associated with a high complication rate following posterior spinal fixation?

Background: Modular pedicle screws have a separate head that can be intraoperatively assembled to the inserted shank. The aim of this study was to report associated intra- and post-operative complications and reoperation rates of posterior spinal fixations with modular pedicle screws at a single center. Methods: A retrospective, institutional chart review was performed on 285 patients who underwent posterior thoracolumbar spinal fusion with modular pedicle screw fixation between January 1, 2017, and December 31, 2019. The primary outcome was failure of the modular screw component. Other measures recorded were length of follow-up, other complications, and need for additional procedures. Results: There were 1,872 modular pedicle screws (average 6.6 per case). There were no (0.0%) screw head dissociations at the rod screw junction. There was 20.8% overall complication rate (59/285) with 25 reoperations: 6 due to non-union and rod breakage, 5 for screw loosening, 7 for adjacent segment disease, 1 for acute postoperative radiculopathy, 1 for epidural hematoma, 2 for deep surgical-site infections, and 3 for superficial surgical-site infections. Other complications included superficial wound dehiscence [8], dural tears [6], non-unions not requiring reoperation [2], lumbar radiculopathies [3], and perioperative medical complications [5]. Conclusions: This study demonstrates that modular pedicle screw fixation has reoperation rates similar to those previously reported for standard pedicle screws. There was no failure at the screw-head junction, and no increases in other complications. Modular pedicle screws present an excellent option to allow surgeons to place pedicle screws without the risk of extra complications.

Pathological Vertebral Fracture Arising From Methotrexate-Associated Lymphoproliferative Disorder in a Patient With Systemic Lupus Erythematosus.

The incidence of lymphoproliferative disorders associated with methotrexate is rising in patients with rheumatoid arthritis. These disorders typically exhibit spontaneous tumor regression upon discontinuation of methotrexate therapy. Spinal lesions associated with these diseases are extremely rare. We present a case of systemic lupus erythematosus in which the patient developed lumbar spine lymphoproliferative disorders secondary to methotrexate therapy, which failed to regress despite discontinuation of the drug, ultimately leading to pathological fracture necessitating posterior spinal fixation. A 60-year-old woman had been diagnosed with systemic lupus erythematosus at the age of 55 years and had been taking prednisolone, hydroxychloroquine, and methotrexate. Throughout the course of her treatment, she experienced recurrent tumefaction and lymph node swelling in various locations. These masses and lymphadenopathy were believed to be potential complications of methotrexate-associated lymphoproliferative disorders, leading to the discontinuation of methotrexate. One month prior to cessation of methotrexate therapy, the patient presented to an orthopedic clinic with lower back pain, and T2-weighted magnetic resonance imaging revealed low signal intensity in the Th10 and L2 vertebrae, initially misdiagnosed as lumbar spinal stenosis. The patient was eventually referred to our department under suspicion of malignant pathology. Computed tomography identified a vertical fracture of the L2 vertebra, which, in conjunction with the imaging results, led to the diagnosis of pathological fracture secondary to methotrexate-associated lymphoproliferative disorder. Following admission to our department, bone biopsy and percutaneous pedicle screw fixation were performed one week later. Pathological examination confirmed the diagnosis of methotrexate-associated lymphoproliferative disorder. Given the possibility of pathological fracture in patients on methotrexate therapy experiencing severe back pain, additional imaging studies should be considered.

Acute Colonic Pseudo-obstruction Following Spinal Fixation for Trauma.

BACKGROUND: Acute colonic pseudo-obstruction (ACPO) is a potentially highly morbid surgical complication. The incidence of ACPO following spinal trauma is unknown, but is likely higher than after elective spinal fusion. The purpose of this study was to establish the incidence of ACPO in patients with major trauma undergoing spinal fusion for unstable thoracic and lumbar fracture, and secondly, to characterize the nature of ACPO in this group, including treatment and complications. METHODS: A metropolitan hospital prospective trauma database was utilized to identify all patients from November 2015 to December 2021 meeting major trauma criteria and undergoing thoracic or lumbar spinal fusion for fracture. Individual records were then evaluated for occurrence of ACPO. ACPO was defined as radiologic evidence of colonic dilation without mechanical obstruction in symptomatic patients undergoing dedicated abdominal imaging. RESULTS: After exclusions, 456 patients with major trauma undergoing thoracic or lumbar spinal fusion were identified. ACPO occurred in 34-an incidence rate of 7.5%. There was no evidence of difference in terms of the spinal fracture type, level, surgical approach, or number of segments fused. There were no perforations; only 2 patients required colonoscopic decompression and none required surgical resection. CONCLUSIONS: ACPO occurred at a high frequency in this group of patients, although it required relatively simple treatment. High vigilance for ACPO should be maintained in trauma patients requiring thoracic or lumbar fixation, with a view to early intervention. The etiology driving the high rates of ACPO in this cohort is not understood and would benefit from further investigation.

Cross-link augmentation enhances CFR-PEEK short fixation in lumbar metastasis stabilization.

Introduction: Spinal stability plays a crucial role in the success of the surgical treatment of lumbar vertebral metastasis and, in current practice, less invasive approaches such as short constructs have been considered. Concurrently, carbon fiber-reinforced (CFR) poly-ether-ether-ketone (PEEK) fixation devices are expanding in oncologic spinal surgery thanks to their radiotransparency and valid mechanical properties. This study attempts to provide an exhaustive biomechanical comparison of different CFR-PEEK surgical stabilizations through a highly reproducible experimental setup. Methods: A Sawbones biomimetic phantom (T12-S1) was tested in flexion, extension, lateral bending, and axial rotation. An hemisome lesion on L3 vertebral body was mimicked and different pedicle screw posterior fixations were realized with implants from CarboFix Orthopedics Ltd: a long construct involving two spinal levels above and below the lesion, and a short construct involving only the levels adjacent to L3, with and without the addition of a transverse rod-rod cross-link; to provide additional insights on its long-term applicability, the event of a pedicle screw loosening was also accounted. Results: Short construct reduced the overloading onset caused by long stabilization. Particularly, the segmental motion contribution less deviated from the physiologic pattern and also the long-chain stiffness was reduced with respect to the prevalent long construct. The use of the cross-link enhanced the short stabilization by making it significantly stiffer in lateral bending and axial rotation, and by limiting mobiliza-tion in case of pedicle screw loosening. Discussion: The present study proved in vitro the biomechanical benefits of cross-link augmentation in short CFR-PEEK fixation, demonstrating it to be a potential alternative to standard long fixation in the surgical management of lumbar metastasis.

Does the Bone Mineral Density of the Lumbar Spine Correlate With Dual-Energy X-ray Absorptiometry T Score? A Cadaveric-Based Analysis of Computed Tomography Densitometry.

BACKGROUND: Pedicle screw loosening is a complication of spinal instrumentation in osteoporotic patients. Dual-energy x-ray absorptiometry scans are not able to detect variations in bone mineral density (BMD) within specific regions of vertebrae. The purpose of this study was to investigate whether spine T scores correlate with cortical and cancellous BMD of pedicles and other 6 anatomical regions of lumbar spine. METHODS: Eleven cadaveric spines with a mean age of 73 years were digitally isolated by applying filters for cortical and cancellous bone on computed tomography images. Eleven L5 vertebrae were separated into 7 anatomical regions of interest using 3-dimensional software modeling. Hounsfield units (HU) were determined for each region and converted to cortical and cancellous BMD with calibration phantoms of known BMD. Correlations between T scores and HU values were calculated using Pearson correlation coefficient. RESULTS: Mean vertebral T score was 0.15. Cortical BMD of pedicles was strongly correlated with T score (R 2 = 0.74). There was moderate correlation between T score and cortical BMD of lamina, inferior articular process (IAP), superior articular process (SAP), spinous process, and vertebral body. There was weak correlation between T score and cortical BMD of transverse process (R 2 = 0.16). Cancellous BMD of vertebral body was strongly correlated with T score (R 2 = 0.82). There was moderate correlation between T score and cancellous BMD of pedicles, spinous process, and transverse process. There was weak correlation between T scores and cancellous BMD of lamina, IAP, and SAP. CONCLUSIONS: There is a strong correlation between T scores and cortical BMD of lumbar pedicle. There is strong correlation between T scores and cancellous BMD of vertebral body. Cortical and cancellous BMD of transverse process and lamina were weakly correlated with T score and less affected by osteoporosis. CLINICAL RELEVANCE: Patients with osteoporosis may especially benefit from the development of extrapedicular fusion strategies due to the relatively higher bone density of these fixation sites.

Multipoint fixation with vascularised fibular bone graft and myotomy for atlanto-axial instability in cervical dystonia: a case report.

Spinal instability is a challenging condition to manage in patients with cervical dystonia. Standard surgical stabilisation approaches may fail to cope with additional stress forces created by spasmodic muscles leading to construct failure either in the immediate or late post-operative period. Long-term stabilisation relies on the management of dystonic symptoms and adjunctive strategies to increase fusion success rate. We discuss the management of a challenging patient with translational C1/2 instability who had three metalwork failures with standard occipito-cervical fixation techniques within a 12 month period. A combined surgical approach using multipoint fixation, sternocleidomastoid myotomy and a vascularised fibular occiput-C2 bone graft successfully prevented further metalwork failure at over 2 years follow up.

Biomechanical Comparison of Different Numbers and Configurations of Cross-Links in Long-Segment Spinal Fixation-An Experimental Study in a Porcine Model.

STUDY DESIGN: Biomechanical study. OBJECTIVE: Cross-links are a type of common clinical spinal instrumentation. However, the effects of the position and number of cross-links have never been investigated in long-segment spinal fixation, and the variables have not been optimized. We conducted an in vitro biomechanical study by using a porcine long-segment spinal model with 5 different crosslink configurations to determine the optimal construct for clinical practice. METHODS: Five modalities with paired segmental screws from T15-L5 were tested in 20 porcine spines. The spines without cross-links composed the control group, Group A; those with a single cross-link from L2-3 composed Group B; those with 2 cross-links from L1-2 and L3-4 composed Group C; those with 2 cross-links from T15-L1 and L4-5 composed Group D; and those with 3 cross-links from T15-L1, L2-3 and L4-5 composed Group E. Spinal stiffnesses in flexion, extension, lateral bending, and axial rotation were compared among 5 different cross-link configurations in 5-level porcine spinal units. RESULTS: Flexional, extensional and lateral bending stiffnesses did not significantly change with an increasing number of cross-links or positions in the construct. Axial stiffness was significantly increased with 2 cross-links compared to one (P < 0.05) and with placement more distant from the center of the long spinal fixation construct (P < 0.05). CONCLUSIONS: Two cross-links individually placed proximal and distal from the center of a construct is an optimal and efficient configuration to achieve biomechanical stability in non-rigid lumbar spines undergoing long-level fixation.

Robotic-assisted spine surgery allows for increased pedicle screw sizes while still improving safety as indicated by elevated triggered electromyographic thresholds.

The present study used triggered electromyographic (EMG) testing as a tool to determine the safety of pedicle screw placement. In this Institutional Review Board exempt review, data from 151 consecutive patients (100 robotic; 51 non-robotic) who had undergone instrumented spinal fusion surgery of the thoracic, lumbar, or sacral regions were analyzed. The sizes of implanted pedicle screws and EMG threshold data were compared between screws that were placed immediately before and after adoption of the robotic technique. The robotic group had significantly larger screws inserted that were wider (7 ± 0.7 vs 6.5 ± 0.3 mm; p < 0.001) and longer (47.8 ± 6.4 vs 45.7 ± 4.3 mm; p < 0.001). The robotic group also had significantly higher stimulation thresholds (34.0 ± 11.9 vs 30.2 ± 9.8 mA; p = 0.002) of the inserted screws. The robotic group stayed in the hospital postoperatively for fewer days (2.3 ± 1.2 vs 2.9 ± 2 days; p = 0.04), but had longer surgery times (174 ± 37.8 vs 146 ± 41.5 min; p < 0.001). This study demonstrated that the use of navigated, robot-assisted surgery allowed for placement of larger pedicle screws without compromising safety, as determined by pedicle screw stimulation thresholds. Future studies should investigate whether these effects become even stronger in a later cohort after surgeons have more experience with the robotic technique. It should also be evaluated whether the larger screw sizes allowed by the robotic technology actually translate into improved long-term clinical outcomes.

Evidence Summary of the nursing of spinal fixation in emergency adult patients with traumatic spinal cord injury / 中国实用护理杂志

Objective:To summarize the relevant evidence for the management of fixation in traumatic spinal cord injury patients, which provides a reference for the clinical care and care of patients.Methods:A systematic search was conducted for evidence related to spinal injuries from domestic and foreign databases, relevant guideline websites, etc. The types of literature were best practice, expert consensus, systematic review, evidence summary, clinical decision-making, etc. The search time was from the establishment of databases to January 31, 2022. Three researchers used the Multidimensional Systematic Review Tool to evaluate systematic review literature. Five researchers used the guideline research and evaluation tool AGREE Ⅱ to evaluate clinical practice guidelines, and used the Australian JBI Evidence-Based Health Care Center (2016) to evaluate expert consensus and expert opinion with the authenticity evaluation tool for expert opinions and professional consensus articles. And extracted and summarized evidence according to the subject.Results:Finally, 10 articles were included, including 4 clinical decision-making, 4 guidelines and 2 systematic evaluations. The 30 pieces of evidence include the assessment, prevention, cervical spinal fixation, and management after traumatic spinal cord injury.Conclusions:The evidence emphasizes the importance of standardized assessment of cervical risk factors in all emergency adult patients with traumatic spinal cord injury. In the emergency department, we need to improve the ability of spinal evaluation and fixation in patients with penetrating neck injury, optimize the timeliness process of emergency trauma, reduce the occurrence of potential complications, and improve patient outcomes.