Short-segment Pedicle Screw Instrumentation Research Articles

Observational study of short-segment pedicle screw fixation for dorsolumbar spine injury: A prospective study

Background: Traumatic injury of dorsolumbar spine is one of the most common sites of spinal injuries because of its location between rigid kyphotic thoracic and mobile lordotic lumbar spine. Its treatment by pedicle screw fixation by short segment (one level above and below the fractured vertebra) or long segment (two levels above and below the fractured vertebra) has always remained a matter of debate. The aim of this study was to assess the functional outcome of short-segment fixation in dorsolumbar spine injury.Materials and Methods: This prospective study was conducted on thirty, single-level, unstable dorsolumbar spine fracture patients, who underwent short-segment pedicle screw instrumentation at Indira Gandhi Institute of Medical Sciences, Patna, between October 2019 and September 2021. All the patients were operated by posterior approach and stabilized the vertebrae with short-segment pedicle screw instrumentation. All patients were followed up for 1 year.Results: Thirty patients (21 males and 9 females) of mean age 34.2 ± 11.74 years were included in the study. The most common mode of injury was fall from height (24 patients, 80%), followed by road traffic accident (six patients, 20%). The most common fracture pattern was compression fractures in 23 (76.67%) patients, followed by burst fractures in 7 (23.33%) patients. The most common level of injury was L1, followed by D12. Neurological improvement of at least one level was seen in 21 patients, and nine patients had no neurological improvement. There was a statistically significant correction of kyphotic angle of 14.9°. At 1 year of follow-up, 21 (70%) patients had <40% Oswestry Disability Index (ODI) and 9 (30%) patients had more than 40% ODI. Out of 30 patients, 2 (6.67%) patients had bedsore, 1 (3.33%) patient had superficial infection, and 1 (3.33%) patient had implant failure.Conclusion: The short-segment posterior instrumentation system is a very stable construct. It maintained the corrected deformity after fracture reduction and spares the motion segment which is sacrificed in the conventional long-segment fixation. The soft tissue dissection, blood loss, and duration of surgery are less in this procedure.

Intervertebral disc injury is the mainspring for the postoperative increase in Cobb Angle after thoracolumbar burst fracture.

A single-institution retrospective study of a cohort of patients who underwent internal fixation spine surgery for thoracolumbar burst fracture (TLBF). To observe the imaging manifestations of intervertebral disc changes in TLBF, to analyze the relationship between the degree of disc injury and the Cobb angle increase. We retrospectively analyzed the data of patients who underwent short-segment pedicle screw instrumentation in the spinal surgery department of a single hospital between January 2014 and December 2017 (n = 90). According to the magnetic resonance imaging characteristics of the superior intervertebral disc tissue of the injured vertebrae before the operation, the intervertebral disc injury was divided into three types, which was used for group allocation: group A, uninjured intervertebral disc group; group B, mild intervertebral disc injury group; and group C, severe intervertebral disc injury group. The main imaging results of the three groups Cobb, IVA, IHI, AHIV, and VAS were compared among groups. Ninety patients were included in the study (n = 38, 32, and 20, in groups A, B, and C, respectively). There was no statistically significant difference in demographics among the three groups (p > .05). 1-year post-surgery, the Cobb angle in group C differed significantly from that in groups A and B (p < .01). There was a significant difference in Cobb angle between groups A and B after internal fixation was removed for 6 months. At 1-year post-surgery, the IHI group C differed significantly from groups A and B (p < .01), while groups A and B were similar (p = .102); however, at 6 months after the internal fixation was removed, the IHI differed significantly between these two groups, also the AHIV between groups A and B was statistically significant (p < .01). The VAS pain score was similar among the three groups. Pearson's test showed that the increase in the Cobb angle was moderately correlated with IVA and IHI, and weakly correlated with AHIV. For TLBF with an intervertebral disc injury, the presurgical degree of intervertebral disc injury is the main reason for the post-surgery increase in the Cobb angle. Thus, diagnosis and treatment of this kind of patient require attention to the risk of spinal deformity.

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.

Short Term Results of Fixation of Unstable Thoracolumbar Fractures with and without Intermediate Screws: A Comparative Study

Background: Posterior short-segment pedicle screw fixation is widely used for unstable thoracolumbar (TL) fractures. Adding a pedicle screw at the fractured vertebrae could significantly improve the stability and decrease the stress on fixation construct. Objective: Compare the efficacy of short segment pedicle screw fixation with and without intermediate screw in correction of the vertebral body height, local kyphosis and maintenance of the correction in the treatment of unstable thoracolumbar spine fractures. Patients and Methods: This study was a prospective cohort study. 40 patients with unstable thoracolumbar fracture were divided randomly into 2 groups according to the surgical method used. In group B, 20 patients underwent fixation via short-segment pedicle screw instrumentation (1 level above and 1 level below the fractured level). In group A, 20 patients received additional screws at the fractured vertebrae. Results: Both groups had significant correction in Cobb angle, anterior body height and local kyphotic angle. However group A had significantly higher correction achieved in Cobb angle (10.35 ± 6.02), anterior body height (1.15 ± 0.50) and local kyphotic angle (13.30 ± 7.54) than group B (3.45 ± 3.94), (0.40 ± 0.41) and (5.05 ± 4.36) respectively. Nevertheless, the differences in VAS score (p=0.759) and ODI (p=0.934) were not significant. Moreover, group A had a significantly lower loss of correction in Cobb angle (p=0.025) after twelve months of follow up. Conclusion: The construct with intermediate screw was associated with not only better correction but also less correction loss after 12 months. However, this was not reflected on clinical outcome.

Treatment of thoracolumbar burst fractures with short-segment pedicle instrumentation and recombinant human bone morphogenetic protein 2 and allogeneic bone grafting in injured vertebra

To investigate the effect of preventing the loss of correction and vertebral defects after thoracolumbar burst fractures treated with recombinant human bone morphogenetic protein 2 (rhBMP-2) and allogeneic bone grafting in injured vertebra uniting short-segment pedicle instrumentation. A prospective randomized controlled study was performed in 48 patients with thoracolumbar fracture who were assigned into 2 groups between June 2013 and June 2015. Control group ( n=24) received treatment with short-segment pedicle screw instrumentation with allogeneic bone implanting in injured vertebra; intervention group ( n=24) received treatment with short-segment pedicle screw instrumentation combining with rhBMP-2 and allogeneic bone grafting in injured vertebra. There was no significant difference in gender, age, injury cause, affected segment, vertebral compression degree, the thoracolumbar injury severity score (TLICS), Frankel grading for neurological symptoms, Cobb angle, compression rate of anterior verterbral height between 2 groups before operation ( P>0.05). The Cobb angle, compression rate of anterior vertebral height, intervertebral height changes, and defects in injured vertebra at last follow-up were compared between 2 groups. All the patients were followed up 21-45 months (mean, 31.3 months). Bone healing was achieved in 2 groups, and there was no significant difference in healing time of fracture between intervention group [(7.6±0.8) months] and control group [(7.5±0.8) months] ( t=0.336, P=0.740). The Frankel grading of all patients were reached grade E at last follow-up. The Cobb angle and compression rate of anterior verterbral height at 1 week after operation and last follow-up were significantly improved when compared with preoperative ones in 2 groups ( P<0.05). There was no significant difference in Cobb angle and compression rate of anterior verterbral height between 2 groups at 1 week after operation ( P>0.05), but the above indexes in intervention group were better than those in control group at last follow-up ( P<0.05). At last follow-up, there was no significant difference of intervertebral height changes of internal fixation adjacent upper position, injured vertebra adjacent upper position, injured vertebra adjacent lower position, and internal fixation adjacent lower position between 2 groups ( P>0.05). Defects in injured vertebra happened in 18 cases (75.0%) in control group and 5 cases (20.8%) in intervention group, showing significant difference ( χ2=14.108, P=0.000); and in patients with defects in injured vertebra, bone defect degree was 7.50%±3.61% in control group, and was 2.70%±0.66% in intervention group, showing significant difference ( t=6.026, P=0.000). Treating thoracolumbar fractures with short-segment pedicle screw instrumentation with rhBMP-2 and allogeneic bone grafting in injured vertebra can prevent the loss of correction and vertebral defects.

Short segment pedicle screw fixation of thoracolumbar fracture: a case series of 33 patients

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Pedicle screw instrumentation in case of fracture spine provides stable fixation. However in absence of experience and proper technique of pedicle screw insertion, it is associated with many complications. We aim to study the results of patients with thoracolumbar fracture stabilized with short segment pedicle screw instrumentation.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; 33 cases of thoracolumbar wedge compression fracture spine presenting to Nair Hospital were included in the study. All patients were operated by the senior author via a posterior approach and short segment pedicle screw fixation. Patients were followed up for one year.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; 33 patients with a mean age were 37.6 years of which 3 were females and 30 were males in our study. Fall from height (93.93%) was the most common mode of injury followed by road traffic accident (6.07%). D12 and L1 were the most common vertebrae involved. Statistically significant (p=0.01) correction in the vertebral body height occurred in the immediate postop period and there was 4.1% loss of correction at final follow-up. There was statistically significant improvements in the Regional angle (p=0.03) and anterior wedge angle (p=0.03). Residual regional angle at final follow-up was found to be &amp;gt;5° in 3 patients. Neurological improvement was seen in 23 (74.19%) patients (p=0.01). No improvements were seen in 8 (25.81%) patients. None of our patients had postoperative worsening of the neurological status. None of the patients had pedicle wall breach on final follow up CT scan.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Short segment fixation in case of wedge fracture can restore the vertebral body height, mean regional angle and mean anterior wedge angle and provide good outcome. There are poor chances of recovery of patient with Frankel grade A. Meticulous dissection and careful technique of pedicle screw insertion, adequate decompression, good contouring of the rod with correction of kyphosis can provide excellent results.&lt;/p&gt;

Trans-Endplate Pedicle Pillar System in Unstable Spinal Burst Fractures: Design, Technique, and Mechanical Evaluation.

BackgroundShort-segment pedicle screw instrumentation (SSPI) is used for unstable burst fractures to correct deformity and stabilize the spine for fusion. However, pedicle screw loosening, pullout, or breakage often occurs due to the large moment applied during spine motion, leading to poor outcomes. The purpose of this study was to test the ability of a newly designed device, the Trans-Endplate Pedicle Pillar System (TEPPS), to enhance SSPI rigidity and decrease the screw bending moment with a simple posterior approach.MethodsSix human cadaveric spines (T11-L3) were harvested. A burst fracture was created at L1, and the SSPI (Moss Miami System) was used for SSPI fixation. Strain gauge sensors were mounted on upper pedicle screws to measure screw load bearing. Segmental motion (T12-L2) was measured under pure moment of 7.5 Nm. The spine was tested sequentially under 4 conditions: intact; first SSPI alone (SSPI-1); SSPI+TEPPS; and second SSPI alone (SSPI-2).ResultsSSPI+TEPPS increased fixation rigidity by 41% in flexion/extension, 28% in lateral bending, and 37% in axial rotation compared with SSPI-1 (P<0.001), and it performed even better compared to SSPI-2 (P<0.001 for all). Importantly, the bending moment on the pedicle screws for SSPI+TEPPS was significantly decreased 63% during spine flexion and 47% in lateral bending (p<0.001).ConclusionTEPPS provided strong anterior support, enhanced SSPI fixation rigidity, and dramatically decreased the load on the pedicle screws. Its biomechanical benefits could potentially improve fusion rates and decrease SSPI instrumentation failure.

Short segment pedicle screw instrumentation with an index level screw and cantilevered hyperlordotic reduction in the treatment of type-A fractures of the thoracolumbar spine

The purpose of this study was to evaluate and compare the effect of short segment pedicle screw instrumentation and an intermediate screw (SSPI+IS) on the radiological outcome of type A thoracolumbar fractures, as judged by the load-sharing classification, percentage canal area reduction and remodelling. We retrospectively evaluated 39 patients who had undergone hyperlordotic SSPI+IS for an AO-Magerl Type-A thoracolumbar fracture. Their mean age was 35.1 (16 to 60) and the mean follow-up was 22.9 months (12 to 36). There were 26 men and 13 women in the study group. In total, 18 patients had a load-sharing classification score of seven and 21 a score of six. All radiographs and CT scans were evaluated for sagittal index, anterior body height compression (%ABC), spinal canal area and encroachment. There were no significant differences between the low and high score groups with respect to age, duration of follow-up, pre-operative sagittal index or pre-operative anterior body height compression (p = 0.217, 0.104, 0.104, and 0.109 respectively). The mean pre-operative sagittal index was 19.6° (12° to 28°) which was corrected to -1.8° (-5° to 3°) post-operatively and 2.4° (0° to 8°) at final follow-up (p = 0.835 for sagittal deformity). No patient needed revision for loss of correction or failure of instrumentation. Hyperlordotic reduction and short segment pedicle screw instrumentation and an intermediate screw is a safe and effective method of treating burst fractures of the thoracolumbar spine. It gives excellent radiological results with a very low rate of failure regardless of whether the fractures have a high or low load-sharing classification score.

Disc Height Change Following Thoracolumbar Burst Fractures Treated with Pedicle Screw Fixation without Fusion

Indirect reduction and posterior pedicle screw fixation have been reported with variable outcomes. However, there is no study that reports on disc space height change following short segment pedicle screw instrumentation without fusion.

Biomechanical effect of the extent of vertebral body fracture on the thoracolumbar spine with pedicle screw fixation: An in vitro study

A fractured vertebra does not transfer load as effectively as the intact vertebra. Patients who undergo surgery using short-segment pedicle screw instrumentation for middle-column injury may experience implant failure when vertebral body comminution is ignored. The purpose of this study was to investigate biomechanical effects of the extent of vertebral body fracture on the thoracolumbar spine after pedicle screw fixation and to evaluate the biomechanical role of anterior reconstruction. Twelve fresh porcine T12–L3 specimens were harvested and divided into two groups. A 2-mm drill bit was used to create holes in the L1 vertebra with two different extents: 1/6 and 1/3 vertebral body involvement. After the pre-injury had been created, specimens were subjected to flexion-compression to create a fracture in the body of the spine. Stiffness under axial-compression and flexion-compression were measured in intact specimens, after the fractured segments had been stabilized using transpedicular fixation, and after transpedicular fixation with anterior grafting. Despite fixation of the injured spine with pedicle screw instrumentation, the axial-compression and flexion-compression stiffness was still significantly lower than that of the intact group ( p < 0.01). The stiffness was associated with the extent of vertebral body involvement; 1/6 vertebral body involvement was stiffer than the 1/3 involvement ( p < 0.01). Additional anterior grafting significantly improved stiffness compared with posterior fixation alone ( p < 0.01), and restored stiffness to the intact level. In any state, stiffness under axial-compression was always significantly greater than that under flexion-compression ( p < 0.01). In conclusion, transpedicular fixation alone cannot provide sufficient stability for thoracolumbar fractures; the construct stability is related to the extent of vertebral body involvement. Recovering mechanical properties of the anterior and middle spinal column is a valuable measure for reducing the load-sharing of the posterior instrument.

Short segment pedicle screw instrumentation and augmentation vertebroplasty in lumbar burst fractures: an experience

To assess the efficacy and feasibility of vertebroplasty and posterior short-segment pedicle screw fixation for the treatment of traumatic lumbar burst fractures. Short-segment pedicle screw instrumentation is a well described technique to reduce and stabilize thoracic and lumbar spine fractures. It is relatively a easy procedure but can only indirectly reduce a fractured vertebral body, and the means of augmenting the anterior column are limited. Hardware failure and a loss of reduction are recognized complications caused by insufficient anterior column support. Patients with traumatic lumbar burst fractures without neurologic deficits were included. After a short segment posterior reduction and fixation, bilateral transpedicular reduction of the endplate was performed using a balloon, and polymethyl methacrylate cement was injected. Pre-operative and post-operative central and anterior heights were assessed with radiographs and MRI. Sixteen patients underwent this procedure, and a substantial reduction of the endplates could be achieved with the technique. All patients recovered uneventfully, and the neurologic examination revealed no deficits. The post-operative radiographs and magnetic resonance images demonstrated a good fracture reduction and filling of the bone defect without unwarranted bone displacement. The central and anterior height of the vertebral body could be restored to 72 and 82% of the estimated intact height, respectively. Complications were cement leakage in three cases without clinical implications and one superficial wound infection. Posterior short-segment pedicle fixation in conjunction with balloon vertebroplasty seems to be a feasible option in the management of lumbar burst fractures, thereby addressing all the three columns through a single approach. Although cement leakage occurred but had no clinical consequences or neurological deficit.

Saturday, November 2, 2001 1:30–2:13 pm Concurrent Session 5B: Trauma: 1:30 Short-segment pedicle instrumentation for thoracolumbar fractures with pedicle screws in the injured vertebra

Purpose of study: To evaluate effectiveness of the short-segment pedicle fixation construct for the treatment of burst thoracolumbar fractures with a pedicle screw inserted in the fractured vertebra. The relationship between the pedicle screw and the bone fragments in the canal are analyzed both before and after pedicle screw insertion in the fractured vertebra with computed tomography (CT) scan.Methods used: Subjects were 34 patients with burst thoracolumbar fractures: 24 men and 10 women. The average age was 34 years. The most common level of fracture was L1. The average spinal canal occupation was 50%. There was no neurological deficit. The surgical procedure was a posterior approach using two pedicle screws in the fractured vertebra; two pedicle screws in the cephalad and two with pedicle-laminar claw one level caudad to the fracture. The instrumentation used is CD titanium CT scans before surgery and immediately after surgery and 6 months after surgery. Minimum follow-up was 36 months.of findings: The vertebra height was corrected and maintained in the last follow-up in all cases. The occupation of the spinal canal remained the same or improved in all cases, and there were no neurological or vascular injuries resulting from the placement of pedicle screws. There was no hardware failure and no reoperations. Bone fusion occurred in all cases.Relationship between findings and existing knowledge: The major concern is the early and late failures described in all short-segment pedicle screw instrumentation studies. However, all avoided pedicle screws in the fractured vertebra. This construct overcomes the hardware failure and loss of correction.Overall significance of findings: Our results suggest that short-segment pedicle screw instrumentation with pedicle screws in the injured vertebra is safe and effective for the treatment of burst thoracolumbar fractures without neurological deficit. Using the intermediate screw and distal pedicle-laminar claw overcomes hardware failure of the instrumentation.Disclosures: Device or drug: CD. Status: approved.Conflict of interest: No conflicts.

Reinforcement of thoracolumbar burst fractures with calcium phosphate cement. A biomechanical study.

A biomechanical study on the stabilization of thoracolumbar burst fractures. To demonstrate that the addition of a calcium phosphate cement into the fractured vertebral body through a transpedicular approach is a feasible technique that improves the stiffness of a transpedicular screw construct. Short segment pedicle screw instrumentation is a commonly used method for reduction and stabilization of unstable burst fractures. Recent investigators, however, have reported a high rate of instrumentation failure and sagittal collapse when there is a loss of anterior column support. In this study, the ability of a new hydroxyapatite cement to augment anterior column support was investigated in a burst fracture model. A cadaveric L1 burst fracture model was stabilized using short segment pedicle screw instrumentation. Specially instrumented-pedicle screws recorded screw-bending moments. The L1 vertebral body was reinforced with the hydroxyapatite cement through a transpedicular approach. Mechanical testing of the instrumented and instrumented-reinforced constructs were performed in flexion, extension, side bending, and torsion. Construct stiffness and screw-bending moments were recorded. Transpedicular vertebral body reconstruction with hydroxyapatite cement reduced pedicle screw-bending moments by 59% in flexion and 38% in extension. Mean initial stiffness in the flexion-extension plane was increased by 40% (P < 0.05). There were no statistically significant differences in these parameters with lateral bending or torsional movements. This hydroxyapatite cement compound augments anterior column stability in a burst fracture model. This technique may improve outcomes in burst fracture patients without the need for a secondary anterior approach.

Early failure of short-segment pedicle instrumentation for thoracolumbar fractures. A preliminary report.

The results after treatment of fifty-two lumbar and thoracolumbar fractures with Cotrel-Dubousset instrumentation were reviewed as part of an ongoing study. Nineteen patients (average duration of follow-up, fifteen months) had been managed with short-segment pedicle-screw instrumentation. This preliminary report outlines the complications and pitfalls identified during the initial healing phase in this subgroup of patients. There were no neurological or vascular injuries due to placement of the pedicle screws, but ten patients had some form of failure of the fixation during the early period of healing. Failure of the fixation was manifested in three ways: progressive kyphosis secondary to the bending of screws (six patients), kyphosis secondary to osseous collapse or vertebral translation without bending of the hardware (three patients), and segmental kyphosis after a caudad screw in the lumbar construct broke (one patient, who had had a combined instrumentation for multiple fractures). Untreated anterior instability, and pre-stressing of the screws when the rods were contoured in situ, resulted in a high rate of failure. The high rate of failure of the hardware associated with this fixation construct suggests that posterior screw fixation alone may not be adequate when Cotrel-Dubousset instrumentation is used for short-segment lumbar arthrodeses. Bent screws or measurable kyphosis did not always herald a clinical failure, but patients who had progressive kyphosis of more than 10 degrees had substantially more pain than did those who had little or no progression. The results reported here are preliminary, and speculation as to the importance of these findings and as to the long-term outcome in these patients would be premature.(ABSTRACT TRUNCATED AT 250 WORDS)