Short-segment Instrumentation Research Articles

Construct length analysis of type B and C cervical and thoracolumbar fractures.

The purpose of this study is to identify if construct length affects the rate of surgical complications and instrumentation revision following surgical fixation of subaxial and thoracolumbar Type B and C fractures. This study evaluates the effect of ankylosing spondylitis/diffuse idiopathic skeletal hyperostosis (AS/DISH) within this population on outcomes. Retrospective review of 91 cervical and 89 thoracolumbar Type B and C fractures. Groups were divided by construct length for analysis: short-segment (constructs spanning two or less segments adjacent to the fracture) and long-segment (constructs spanning more than two segments adjacent to the vertebral fracture). For cervical fractures, construct length did not impact surgical complications (P = 0.641), surgical hardware revision (P = 0.167), or kyphotic change (P = 0.994). For thoracolumbar fractures, construct length did not impact surgical complications (P = 0.508), surgical hardware revision (P = 0.224), and kyphotic change (P = 0.278). Cervical Type B fractures were nonsignificantly more likely to have worsened kyphosis (P = 0.058) than Type C fractures. Assessing all regions of the spine, a diagnosis of AS/DISH was associated with an increase in kyphosis (P = 0.030) and a diagnosis of osteoporosis was associated with surgical hardware failure (P = 0.006). Patients with short-segment instrumentation have similar surgical outcomes and changes in kyphosis compared to those with long-segment instrumentation. A diagnosis of AS/DISH or osteoporosis was associated with worse surgical outcomes.

Short segment posterior fixation of unstable thoracolumbar vertebral fractures with fractured vertebra augmentation with intermediate pedicle screw - a clinicoradiological analysis.

Unstable thoracolumbar burst fractures are routinely encountered in orthopedic practice. Recently, short-segment fixation with pedicle screw augmentation of the fractured vertebra for unstable thoracolumbar burst fractures has gained popularity. Nonetheless, the maintenance of the kyphotic correction during the follow-up period remains controversial. This study aimed to examine the clinical-radiological outcomes, complications, and functional outcomes of fractured vertebrae augmentation with intermediate pedicle screws in short-segment instrumentation in acute thoracolumbar spine fractures. This retrospective study was conducted in the Department of Orthopedics, All India Institute of Medical Sciences, Jodhpur, using medical records from January 2021 to October 2022. Parameters such as local kyphosis correction, loss of kyphotic correction at final follow-up, anterior body height correction (%), and loss of correction (%) at final follow-up were measured as primary outcomes. Various other parameters such as operative time, blood loss, length of hospital stay, and visual analog scale were measured as secondary outcomes. The mean correction obtained via surgery in the immediate postoperative period was 13.7±2.3 degrees. The mean loss of correction at the final follow-up was 4.1±2.0 degrees, and the mean final local kyphotic angle was 7.2±2.4 degrees (P<0.05). The mean correction obtained via surgery in the immediate postoperative period was 37.2%±9.0%. The mean loss of correction at the final follow-up was 10.5%±5.3%, and the mean final anterior vertebral body height maintained was 72%±11.0% (P<0.05). Short-segment posterior fixation with pedicle screw augmentation achieves good correction of local kyphotic angle and anterior vertebral height in the immediate postoperative period, but some loss of correction at final follow-up is common. In our study, the loss of correction corresponded directly to the load-sharing score.

Evaluation of the effectiveness of the short-segment thoracolumbar instrumentation

Aims: This prospective study aimed to compare the long-term follow-up findings of patients with short-segment thoracolumbar instrumentation with the long-term follow-up findings results of patients with long-segment thoracolumbar instrumentation. Merthods: Patients who underwent surgery for a thoracolumbar junction spine fracture were included in this study. The patient's age, gender, and neurological impairment, "AOSpine Classification Scale", "Visual Analog Scale (VAS)", "modified Japanese Orthopedic Association (mJOA)" and "Oswestry Disability Index (ODI)" scores, pedicle and/or pars interarticularis fractures, anterior, middle, and posterior height loss of the fractured vertebral body (mm), the height loss rate of the fractured vertebra, angulation degree, sagittal and axial spinal canal diameters (mm) and presence of bone fragment extending into the spinal canal on CT images were recorded at admission to the hospital, and the end of the sixth month after surgical intervention. Duration of anesthesia and surgery time, the amount of bleeding during the surgery, the radiation level (mGy) released by fluoroscopy, performing laminectomy, length of stay in the intensive care unit, and hospital were recorded. Additionally, the stability and integrity of the instrumentation were examined with dynamic X-ray images. Results: Preoperative fractured vertebra collapse rates (t=4.175, p=0.001) and surgery times (t=4.175, p=0.001) were different between groups In the long-segment group, preoperative VAS scores (Z=-2.687, p=0.007), mJOA scores (Z=-2.585, p=0.010), and ODI scores (t=53.253, p&lt;0.001) were different from postoperative long-term follow-up values. In addition, in the short segment group, preoperative VAS scores (Z=-2.214, p=0.027), mJOA scores (Z=-2.333, p=0.020), and ODI scores (t=48.338, p&lt;0.001) were different from the postoperative long-term follow-up values. ROC-curve analysis and Logistic Regression analysis results revealed that any study parameter could not predict the decision-making for inserting screws into the fractured vertebra, the need for laminectomy, the risk of developing postoperative instability, or the worse prognosis risk of mJOA. Conclusion: This study's results showed that short-segment instrumentation, which is performed by inserting a screw into the fractured vertebra, is as effective as long-segment instrumentation in providing both clinical and radiological improvement in patients. At the same time, it has advantages such as less operating time, less surgical bleeding, and short anesthesia time. However, it was determined that no parameter of the study could predict the placement of screws in the fractured spine, the need for laminectomy, the risk of postoperative instability, or the prognosis risk of mJOA. Therefore, it was concluded that conducting this study on a larger patient population would be appropriate.

Minimally Invasive Techniques in the Surgical Management of Traumatic Pediatric Thoracolumbar Fractures

BackgroundThoracolumbar (TL) fractures are uncommon injuries in children. While surgical treatment is recommended for unstable TL fractures, there is no consensus on the appropriate surgical treatment. We present a case series of pediatric patients with traumatic TL fractures treated with minimally invasive (MI) surgical techniques. We discuss our early experience and technical challenges with navigation and robot-assisted (RA) fixation, which has not been reported in young children. MethodsA retrospective review of a prospectively maintained trauma database from February 2018-February 2023 of all pediatric patients (< 18 years old) undergoing percutaneous fixation for unstable TL fractures was performed. MI techniques included fluoroscopy and/or navigation-guided or RA. Details of the clinical course, radiographic findings and technical challenges were reviewed. ResultsA cohort of 12 patients with ages ranging from 4-17 years of age were identified. There was a total of 6 (50%) Chance fractures, 2 (16%) pars, 2 (16%) pedicles, 1 (8%) burst, and 1 (8%) other fracture. 9 patients had fractures involving the lumbar spine and the remaining 3 had thoracic fractures. In all cases, percutaneous pedicle screws were placed above and below the fracture with the use of neuro-navigation or RA navigation (n=2). Blood loss was less than 30 milliliters (ml) for single level fractures and instrumented fusion. Two patients had hardware-related complications. At follow-up, (mean 9.67 months from surgery) most of the radiologic imaging showed stable alignment and patients were doing well clinically. ConclusionsOur early experience shows that short segment instrumentation through a MI approach is a safe and effective surgical option for young pediatric patients with good clinical outcomes and favorable radiographic post-operative finding.

Functional and Radiological Outcome of Short Same Segment Instrumentation in Thoracolumbar Burst fracture.

Thoracolumbar region is important biomechanics transition zone in which rigid thoracic and flexible lumbar spine meet. This area is highly vulnerable to traumatic spinal fracture.Among all spine fracture, compression type is most common and managed conservatively. Thoracolumbar spine fracture can be associated with neurological deficit, spinal instability. The optimal treatment for these injuries is still controversy and subject for research. This retrospective study included 30 patients with single level thoracolumbar fracture.All the patients clinical and radiological parameters were evaluated preoperative, post-operative and 1 year follow up. Clinical parameters were included Visual analogue score, Oswestry disability index. Radiologic measurement were regional kyphotic angle by cobb's method and anterior vertebral body height loss (Mumford' santerior body compression equation method) in X-ray. All the data were analysed in SPSS version 20. A total of 30 patients were included in this study,19 were male.The mean age of the patients were 40.8±13.The main cause of injury was fall from height,26 patients. The most common level of fracture vertebra was L1,11 patients.The mean difference of preop and postop kyphosis was 11.70±50 with P<0.05.The mean difference of preop Oswestry disability index and postop Oswestry disability index score was 30.7±7.6 with T score 22(P<0.05).The preop and postop Visual analogue score score also improved ,mean difference was 2.8±1(P<0.05). Short segment instrumentation with placement of pedicle screw at fracture vertebra is one option in the treatment of thoracolumbar burst fracture.

Clinical Outcome of Pedicle-Sparing Transfacet Diskectomy and Fusion with Segmental Instrumentation for Thoracic Disc Herniation.

Thoracic disk herniations (TDHs) are relatively rare compared with their cervical and lumbar counterparts. Posterior approaches allow for a simpler and less invasive surgery than anterior and lateral approaches. A pedicle-sparing transfacet approach was initially described in 1995, and modified in 2010. A few clinical series have reported the outcome of this procedure in patients with TDH. This study aimed to evaluate the outcomes and complications of pedicle-sparing transfacet diskectomy with interbody fusion and segmental instrumentation in patients with TDH. Twenty-one consecutive patients with symptomatic TDH referred to our tertiary care center were included in this retrospective study. All patients underwent a pedicle-sparing transfacet diskectomy with polyetheretherketone (PEEK) cage interbody fusion and short segmental instrumentation. Distribution of TDH, operative duration, blood loss, Visual Analog Scale (VAS) pain scores, Nurick grades, modified Japanese Orthopaedic Association (mJOA) scores, and fusion rate were assessed. All patients had single-level herniations. The most common location was T12-L1 (38.1%), followed by T11-T12 (33.3%). All patients were successfully operated on with no cerebrospinal fluid (CSF) leaks or wrong-level surgery. The VAS scores significantly diminished from 4.9 (preoperatively) to 2 (18 months after surgery). The average mJOA score increased from 4.6 to 8.5, and the average Nurick grade decreased from 3.1 to 1.6. All patients reported significant improvement in quality of life relative to their preoperative status. A modified pedicle-sparing transfacet diskectomy combined with PEEK cage interbody fusion and segmental instrumentation offers a safe and less invasive approach for the treatment of TDHs.

491 Durability of Short Segment Instrumentation With Vertebrectomy in the Setting of Metastatic Disease to the Thoracic Spine

INTRODUCTION: Current treatment of spinal metastases in the thoracic spine requiring vertebrectomy entails pedicle screw fixation at least two levels above and below the level of reconstruction. METHODS: We reviewed a series of 30 patients treated for single-level, non-junctional (T2 to T11) thoracic spinal metastasis via single level vertebrectomy with posterior short segment instrumentation. The primary outcome was need for reoperation due to construct failure. Secondary outcomes included local tumor recurrence, pain scores, neurological function, estimated blood loss, operative time, length of hospital stay, and post-operative wound complications. RESULTS: The most common primary tumor origin was non-small cell lung carcinoma (n = 9). All patients had a SINS score of at least 10 and Bilsky Grade of 2 or 3. Mean intraoperative blood loss was 605 mL (range 50 – 1200 mL) and mean operative time was 260.73 minutes (range 169 to 442 minutes). Two patients suffered perioperative complications but there was no construct failure or need for revision surgery at any time during the follow-up period. Mean length of follow-up was 24 months (range 1-65 months). An overall improvement in pain was seen postoperatively (7.67 versus 2.77, p &lt; 0.001) and no patient experienced worsening neurological function. Average length of stay was six days. Three patients in this cohort had local tumor recurrence, although two of these patients suffered from a radioresistant tumor pathology. CONCLUSIONS: Our results encourage consideration of this less invasive technique in the management of patients suffering from metastatic disease requiring vertebrectomy and reconstruction in the non-junctional thoracic spine.

Predictive Markers in Decision-Making for Screwing the Fractured Thoracolumbar Vertebra in the Short-Segment Instrumentation.

In this study, it is aimed to compare the long-term results of patients with short-segment instrumentation where screws were inserted into the fractured vertebra with those of patients with long-segment instrumentation applied by skipping the fractured vertebra and reveal the predictive markers in decision-making for screwing fractured vertebra. Patients were separated into two groups, namely, Group A (patients in which the fractured vertebra and vertebrae above and below the fractured vertebra were screwed (short-segment instrumentation, n=22) and Group B (patients in whom the fractured vertebra was not screwed, whereas two vertebrae above and below the fractured vertebra were screwed (long-segment instrumentation, n=27). The presence of pedicle fracture, AOSpine Classification Scale score, the height of the fractured vertebra, vertebra height below the fractured vertebra, spinal canal diameter, and duration of stay in hospital were different between the groups, preoperatively (p<0.05). Fractured vertebra height, vertebra height below the fractured vertebra, and Karnofsky Performance Scale score were different between the groups in long-term follow-up (p<0.05). The preoperative measurement values were similar to each group's postoperative long-term follow-up results. Logistic regression analysis revealed that the presence of pedicle fracture, AOSpine Classification Scale score, vertebra height below the fractured vertebra, and spinal canal diameter could be the best parameters in decision-making for screwing fractured vertebra (p<0.05). Both instrumentation procedures were observed to have similar effectiveness in preventing a collapse in fractured vertebra during long-term follow-up. It was thought that the AOSpine Classification Scale score, presence of pedicle fracture, vertebra height below the fractured vertebra, and spinal canal diameter could be used as predictive markers in decision-making for screwing fractured vertebrae. Consequently, it was concluded that patients with pedicle fractures, more height loss in the vertebra below the fractured vertebra, and narrow spinal canal would not be suitable for screwing the fractured vertebra.

Response to: Long versus Short Segment Instrumentation in Osteoporotic Thoracolumbar Vertebral Fracture.

Response to: Long versus Short Segment Instrumentation in Osteoporotic Thoracolumbar Vertebral Fracture.

Surgical Outcome of Short Segment Instrumentation including Fracture Vertebrae of Thoracolumbar Burst Fracture

Surgical Outcome of Short Segment Instrumentation including Fracture Vertebrae of Thoracolumbar Burst Fracture

Biomechanical analysis of reduction technique for lumbar spondylolisthesis: anterior lever versus posterior lever reduction method

BackgroundReduction of lumbar spondylolisthesis during spinal fusion surgery is important for improving the fusion rate and restoring the sagittal alignment. Despite the variety of reduction methods, the fundamental mechanics of lumbar spondylolisthesis reduction remain unclear. This study aimed to investigate the biomechanical behavior while performing spondylolisthesis reduction with the anterior and posterior lever reduction method.MethodsWe developed an L4–L5 spondylolisthesis model using sawbones. Two spine surgeons performed the simulated reduction with a customized Cobb elevator. The following data were collected: the torque and angular motion of Cobb, displacement of vertebral bodies, change of lordotic angle between L4 and L5, total axial force and torque applied on the model, and force received by adjacent disc.ResultsLess torque value (116 N-cm vs. 155 N-cm) and greater angular motion (53o vs. 38o) of Cobb elevator were observed in anterior lever reduction. Moreover, the total axial force received by the entire model was greater in the posterior lever method than that in the anterior lever method (40.8 N vs. 16.38 N). Besides, the displacement of both vertebral bodies was greater in the anterior lever method.ConclusionsThe anterior lever reduction is a more effort-saving method than the posterior lever reduction method. The existing evidence supports the biomechanical advantage of the anterior reduction method, which might be one of the contributing factors to successfully treating high-grade lumbar spondylolisthesis with short-segment instrumentation.

Role of Including the Index level in Short Segment Pedicular Fixation in Traumatic Thoraco-Lumbar Fractures

Abstract Background It is generally acknowledged that short-segment pedicle screw instrumentation is the preferred surgical method for thoracolumbar fractures. However, the use of short-segment instrumentation with or without intermediate screws at the fracture level remains controversial. This review will evaluate the evidence available to date regarding the efficacy of including the fracture level in trans-pedicular screw short segment fixation, to assess clinical and radiological outcome. Objectives Our primary objective is evaluating the efficacy and outcome of including the fractured level vertebra in short segment fixation. And concerns regarding the use of pedicle screws into the fractured vertebra as to whether it is safe to insert a screw through a broken bone. Our secondary objective analyzing the importance of posterior pedicle screw fixation in unstable thoracolumbar fractures. Methods The following electronic databases will be searched from 1992 to 2018: PubMed, Google scholar search engine. Cochrane database of systematic reviews, EMBASE and science Direct, using the keywords “TLICS”, "index screw", “short segment fixation”, "Thoracolumbar spine trauma", "traumatic spine injury", "spinal cord injury", "spine trauma", "role", “reliability”.Studies will be eligible if they contain the target keywords in title or abstract, addressing our age group. Afterwards the full text of the articles will be reviewed to exclude full texts not fulfilling the criteria or deviating from the initial impression taken from the title/abstract reviewing. References/bibliography of the selected articles will be examined to evaluate potential for further research and possible inclusion in the analysis. Any differences will be sorted by discussion between study team (student, director, and co-directors). Results A total of 3010 studies were screened for eligibility , 8 studies were included in our systematic review for comparing the short segment fixation “including” the fracture level with “conventional” methods whether short or long segment fixation. Overall study population reached 512 patients. Analysis showed comparable results regarding clinical picture and radiography, showing highly statistically significant difference in favor of “including” index level in fixation in post operative kyphosis angle correction, loss of correction of kyphosis angle through follow up until 2 years and loss of correction of AVH, also statistically significant difference in rate of implant failure in favor for “including” group, and with no significant difference in operative time , blood loss and VAS for post-operative pain. Conclusion We conclude that Short segment fixation including the fracture level is a promising surgical option when it comes to thoraco-lumbar unstable fractures. In conclusion, inclusion of the fracture level into the construct offers a better kyphosis correction, in addition to fewer instrument failures, without additional complications, and with a comparable-if not better-clinical outcome, the radiologic correction achieved is maintained even at the end of 2 years and reflected in good functional outcomes. We recommend insertion of screws into pedicles of the fractured thoracolumbar vertebra when considering a short segment posterior fixation, especially in Magerl type C fractures. Large population prospective randomized controlled studies and clinical trials are recommended for more high level evidence data.

Comparing porous tantalum fusion implants and iliac crest bone grafts for spondylodesis of thoracolumbar burst fractures: Prospectice Cohort study

The aim of this study was to compare two different techniques of performing one-level spondylodesis for thoracolumbar burst fractures using either an autologous iliac crest bone graft (ICBG) or a porous tantalum fusion implant (PTFI). In a prospective nonrandomized study, 44 patients (20 women, 24 men; average age 43.1 ± 13.2 years) suffering from severe thoracolumbar burst fractures were treated with combined anterior–posterior stabilization. An ICBG was used in 21 cases, and a PTFI was used in the other 23 cases. A two-year clinical and radiographic follow-up was carried out. There were no statistically significant differences in age, sex, localization/classification of the fracture, or visual analog scale (VAS) before injury between the two groups. All 44 patients were followed up for an average period of 533 days (range 173–1567). The sagittal spinal profile was restored by an average of 11.1° (ICBG) vs. 14.3° (PTFI) (monosegmental Cobb angle). Loss of correction until the last follow-up tended to be higher in the patients treated with ICBG than in those treated with PTFI (mean: 2.8° vs. 1.6°). Furthermore, significantly better restoration of the sagittal profile was obtained with the PTFI than with the iliac bone graft at the long-term follow-up (mean: ICBG 7.8°, PTFI 12.3°; p < 0.005). Short-segment posterior instrumentation combined with anterior one-level spondylodesis using either an ICBG or a PTFI resulted in sufficient correction of posttraumatic segmental kyphosis. PTFI might be a good alternative for autologous bone grafting and prevent donor site morbidities.

Early surgery with antibiotic medication was effective and efficient in treating pyogenic spondylodiscitis

BackgroundPyogenic spondylodiscitis (PSD) is challenging to the orthopedist with regards to diagnosis and treatment. The present study was designed to assess and suggest the most indicative diagnostic method and evaluate the effect of surgery comprising of debridement, instrumentation and fusion in treating PSD.MethodsSeventy-six patients with PSD who underwent surgical intervention were retrospectively enrolled. Their medical documents, corrections of spinal alignment and improvements in neurological function were assessed. Surgical approaches were compared in lumbar surgeries regarding the improvements in lordotic angle and neurological function.ResultsElevated c-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were found in 77.6 and 71.1% patients respectively. Infectious lesions were found at lumbar (85.5%), cervical (10.5%) and thoracic (3.9%), ascertained with contrast-enhanced MRI. For lumbar patients, surgery was performed through the anterior (26.2%), posterior (49.2%) or combined approach (24.6%), and differences in improvement of lordosis and neurological function between each approach were insignificant. The pathogen was identified in 22.4% of the patients. Postoperative antibiotic therapy was managed against the result of susceptibility test, or empirically given to patients with negative cultures. All antibiotic therapy was initiated intravenously for 4–6 weeks and orally for 6 weeks.ConclusionElevated CRP and/or ESR, with focal hyper-intensity on contrast-enhanced MRI are suggestive of possible PSD. Surgical intervention comprising of debridement, short-segment instrumentation and fusion that early applied to the PSD patients followed by postoperative antibiotic therapy have demonstrated preferable outcomes, but require further study.The translational potential of this articleThis article advocates early surgery to enable prompt diagnosis and treatment of PSD, and thus guarantee favorable outcomes for patients, as is shown in our study. In addition, different surgical approaches to the lesions were compared and discussed in this manuscript, but no differences in outcome between approaches were found. This suggests that thorough debridement should be prioritized over selection of surgical approach. In summary, this article has large translational potential to be applied clinically.

Efficacy of Transpedicular Vertebrectomy With Short Segment Instrumentation for the Treatment of Thoracic Spinal Metastasis

Online date: November 16, 2020 This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Outcome of pedicle screw fixation with transpedicular bone grafting in fracture of thoracolumbar vertebrae

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Posterior short segment instrumentation for thoracolumbar fracture is known for high implant failure rate because of the lack of anterior support. Anterior body augmentation by transpedicular bone grafting has been developed as an alternative to overcome this failure. In this study, we have evaluated the outcome of the cases of the unstable thoracolumbar spine injuries managed surgically with pedicle screws and transpedicular bone grafting.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; 20 patients were included in this study and were followed up for up to 6 months postoperatively. We assessed the outcome of each patient with Frankel scale and visual analog score (VAS) post-operatively clinically and radio logically by measuring Cobb’s angle and anterior vertebral body height post-operatively on follow-up at 6 weeks, 12 weeks, and 24 weeks.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; We found that males had higher incidence with most common mode of injury was fall from height. D12 was single most involved vertebrae. The average Cobb’s angle during preoperative stage was 12 degrees and 22.05 degrees at 6th week and this was maintained till 24th week. The mean difference of anterior vertebral body height between pre-operative and 24th post-operative week was 7.15 mm. The mean VAS pre-operatively was 9.8 which changed to 0.75 at 24 weeks follow up. These were statistically highly significant.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Our study established that Pedicle screw fixation with transpedicular bone grafting has a satisfactory result and can restore vertebral height, increase the stability of the injured vertebrae and leads to a significant improvement in the patient’s quality of life.&lt;/p&gt;

Myelomeningocele and Kyphosis: Natural History of the Disease and the First Results of a New Surgical Technique.

To define the natural course of kyphosis, and to evaluate the efficiency of a new technique in surgical correction of kyphosis seen in myelomeningocele(MM) patients. We retrospectively reviewed our patients with MM. The rate of kyphosis, mean angle of progression and mean angle of surgical correction were evaluated. Surgical correction was achieved with the same technique in all patients; kyphectomy, short segment instrumentation with plate system and long segment instrumentation with screw-rod system. A total of 14 patients were treated surgically and the mean age at the surgery was 39 months. The incidence of kyphosis rate was %21 in this study. The mean angle of kyphosis was 85.8°. Average angle of progression was 15.7° whereas it was 6.3° degree in patients whose kyphosis angle ?90 and > 90 degree, respectively, at birth. 14 patients were treated surgically and the mean age at the surgery was 39 months. The mean angle of correction of kyphosis was 86 degree. The most common complications were wound dehiscence and cerebro-spinal fluid leak. One patient died 3 months after surgery, and one patient was reoperated due to pull-out of screws. Effective surgical correction of kyphosis in MM patients can be achieved with the described surgical technique even in younger ages. Prospective studies in larger study population are necessary for more accurate definition of natural history of kyphosis in MM patients.

Short-Segment Instrumentation with Fractured Vertebrae Augmentation by Screws and Bone Substitute for Thoracolumbar Unstable Burst Fractures.

Background For thoracolumbar burst fractures, traditional four-screw (one above and one below) short-segment instrumentation is popular and has a high failure rate. Additional augmentation at the fractured vertebrae is believed to reduce surgical failure. The purpose of this study was to examine the clinical and radiographic results of patients who underwent short-segment posterior instrumentation with augmentation by screws and bone substitutes at the fractured vertebrae and to compare these data to those of patients who underwent long-segment instrumentation for thoracolumbar burst fractures. Methods The study group had twenty patients who underwent short-segment instrumentation with additional augmentation by two screws and bone substitutes at the fractured vertebrae. The control group contained twenty-two patients who underwent eight-screw long instrumentation without vertebra augmentation. Local kyphosis and the anterior body height of the fractured vertebrae were measured. The severity of the fractured vertebrae was evaluated with the load sharing classification (LSC). Any implant failure or loss of correction >10° at the final follow-up was defined as surgical failure. Results Both groups had similar distributions in terms of age, sex, the injured level, and the mechanism of injury before operation. During the operation, the study group had significantly less blood loss (136.0 vs. 363.6 ml, p=0.001) and required shorter operating times (146.8 vs. 157.5 minutes, p=0.112) than the control group. Immediately after surgery, the study group had better correction of the local kyphosis angle (13.4° vs. 11.9°, p=0.212) and restoration of the anterior height (34.7% vs. 31.0%, p=0.326) than the control group. At the final follow-up, no patients in the study group and only one patient in the control group experienced surgical failure. Conclusions Patients with thoracolumbar burst fractures who received six-screw short-segment posterior fixators with augmentation at the level of the fractured vertebrae via injectable artificial bone substitute achieved satisfactory clinical and radiographic results, and this method could replace long-segment instrumentation methods used in unstable thoracolumbar burst fractures.

Efficacy of Vertebroplasty in Short-Segment Pedicle Screw Fixation of Thoracolumbar Fractures: A Meta-Analysis.

BackgroundShort-segment pedicle screw instrumentation provides superior outcomes in treating thoracolumbar fractures. Nevertheless, the effect of intermediate screws on the outcome of short-segment instrumentation at the fracture level has not been specifically analyzed. We performed an update meta-analysis of the effect of additional vertebroplasty on the outcome of short-segment instrumentation to determine the role of screws for patients with fractured vertebra.Material/MethodsA systematic literature search was conducted, updated to January 2019, in terms of the efficacy of additional vertebroplasty on the outcome of short-segment instrumentation at the fracture level. After rigorous quality review, we extracted the data from qualified clinical studies. We further analyzed odds ratios (ORs) of the endpoints of interest based on the included trials.ResultsCompared with the control group, short-segmental fixation combined with intermediate screws restored Cobb angle (P<0.001) and reduced anterior vertebral height compression (P=0.001). However, our results did not reveal statistically significant differences in operative time (P=0.28) or estimated blood loss (P=0.23). A statistically significant difference was observed in mean hospital stay (P=0.02).ConclusionsReinforcement with fracture-level screw combination can help stabilize the fractures and restore the anatomy. Nevertheless, additional trials and studies with longer follow-ups and on larger populations are warranted to confirm the current findings.

Finite element analysis comparing short-segment instrumentation with conventional pedicle screws and the Schanz pedicle screw in lumbar 1 fractures.

Previous finite element studies of thoracolumbar fractures were mostly based on simulation analysis of one single object, which was difficult to objectively evaluate the differences between conventional pedicle screws and Schanz pedicle screws. The aim of this study was to evaluate the stress of screw and injured vertebrae displacement using the finite element model of conventional pedicle screw and Schanz pedicle screw instrumentation for the treatment of lumbar 1 fractures. Data of eight healthy volunteers were used to simulate the finite element model. The instrumentation models were divided into four groups: moderate fracture conventional (MC), moderate fracture Schanz (MS), unstable/severe fracture conventional (UC), and unstable/severe fracture Schanz (US) pedicle screw groups. The maximum screw stress and lumbar 1 displacement/micro-motion in each group increased with the increase of torque and/or load. Under the same fracture, maximum von Mises stress of conventional pedicle screw (MC/UC) was larger than Schanz pedicle screw (MS/US) (P < 0.05) and lumbar 1 displacement/micro-motion of Schanz pedicle screw (MS/US) was larger than conventional pedicle screw (MC/UC) (P < 0.05). Under the same screws, the maximum von Mises stress and displacement/micro-motion of unstable fracture (UC/US) were larger than moderate fracture (MC/MS) (P < 0.05). Posterior short-segment instrumentation with Schanz pedicle screws were recommended for unstable fractures. The compression displacement/micro-motion of bony defect during flexion may lead to the postoperative re-collapse of injured vertebrae.