Correct positioning of pedicle screws with a percutaneous minimal invasive system in spine trauma

Application of 3-dimensional printing guide template and pointed lotus-style regulator in percutaneous pedicle screw fixation for thoracolumbar fractures

This study aims to analysis the efficacy of the 3D printing percutaneous guide template in combination with the pointed lotus-style regulator in percutaneous pedicle screw fixation. 60 thoracolumbar fractures patients receiving percutaneous pedicle screw fixation (PPSF) were enrolled and randomly divided into 3 groups. Patients in Group A received traditional PPSF, while patients in Group B received PPSF with flat end lotus-style regulator and patients in Group C received PPSF with pointed lotus-style regulator. The experimental results showed that the highest number of pedicle screw successfully inserted by the first time was in group C, while lowest in group A (P < 0.05). The total time of fluoroscopy and operation were lower in group C, and higher in group A (P < 0.05). VAS and ODI scores were all lower after surgery than before surgery in 3groups. VAS and ODI scores were lower in group B and C, compared with group A at day 1, 7 after surgery (P < 0.05). KA decreased significantly in 3 groups after surgery and no difference in KA change between 3 groups (P > 0.05). Taken together, Application of the 3D printing guide template in combination with pointed lotus-style regulator improved the accuracy of pedicle insertion.

Trial registration: ClinicalTrials.gov Identifier: NCT04980131. Registered 18/07/2021.

Assessment of the outcome of percutaneous pedicle screws in management of degenerative and traumatic dorsal and lumbar pathologies

Background

Percutaneous pedicle screw technique is relatively a recent technique that evolved the concept of posterior spinal instrumentation, utilizing familiar fluoroscopic landmarks to guide the procedure of screws insertion, which despite being technically demanding, it avoids the Musculo-ligamentous damage associated with the conventional posterior technique.

Aim of the work

This study aims to report our experience in managing traumatic and degenerative spine pathologies by the minimally invasive percutaneous technique and assessing its radiological and functional outcome.

Materials and methods

A prospective observational study that included the analysis of the functional, operative, biochemical, and radiological outcomes of 20 patients who underwent uniplanar fluoroscopic-guided dorsal and/or lumbar percutaneous pedicle screw fixation procedures with or without fusion using the sextant, longitude, and Spineart system and any reported complications between January 2018 and December 2019.

Results

The clinical and radiological analysis of 100 percutaneous pedicle screws in degenerative (n:11) and traumatic (n:9) dorsal and/or lumbar cases revealed that the biomechanical stabilizing characteristics are comparable to the conventional posterior approach with the added benefits of the paraspinal muscle-sparing. Satisfactory functional outcome represented in the improvement of the postoperative back pain visual analog score and Oswestry Disability Index Score with acceptable morbidity and complications rate was noticed.

Conclusions

Percutanous pedicle screw fixation is a landmark in the evolution of the minimally invasive spine surgery which can be a safe alternative to the conventional posterior muscle stripping technique with a comparable functional and radiological outcome and good biomechanical profile and an acceptable morbidity rate.

A cadaveric precision and accuracy analysis of augmented reality-mediated percutaneous pedicle implant insertion

OBJECTIVE

Augmented reality-mediated spine surgery (ARMSS) is a minimally invasive novel technology that has the potential to increase the efficiency, accuracy, and safety of conventional percutaneous pedicle screw insertion methods. Visual 3D spinal anatomical and 2D navigation images are directly projected onto the operator's retina and superimposed over the surgical field, eliminating field of vision and attention shift to a remote display. The objective of this cadaveric study was to assess the accuracy and precision of percutaneous ARMSS pedicle implant insertion.

METHODS

Instrumentation was placed in 5 cadaveric torsos via ARMSS with the xvision augmented reality head-mounted display (AR-HMD) platform at levels ranging from T5 to S1 for a total of 113 total implants (93 pedicle screws and 20 Jamshidi needles). Postprocedural CT scans were graded by two independent neuroradiologists using the Gertzbein-Robbins scale (grades A-E) for clinical accuracy. Technical precision was calculated using superimposition analysis employing the Medical Image Interaction Toolkit to yield angular trajectory (°) and linear screw tip (mm) deviation from the virtual pedicle screw position compared with the actual pedicle screw position on postprocedural CT imaging.

RESULTS

The overall implant insertion clinical accuracy achieved was 99.1%. Lumbosacral and thoracic clinical accuracies were 100% and 98.2%, respectively. Specifically, among all implants inserted, 112 were noted to be Gertzbein-Robbins grade A or B (99.12%), with only 1 medial Gertzbein-Robbins grade C breach (> 2-mm pedicle breach) in a thoracic pedicle at T9. Precision analysis of the inserted pedicle screws yielded a mean screw tip linear deviation of 1.98 mm (99% CI 1.74-2.22 mm) and a mean angular error of 1.29° (99% CI 1.11°-1.46°) from the projected trajectory. These data compare favorably with data from existing navigation platforms and regulatory precision requirements mandating that linear and angular deviation be less than 3 mm (p < 0.01) and 3° (p < 0.01), respectively.

CONCLUSIONS

Percutaneous ARMSS pedicle implant insertion is a technically feasible, accurate, and highly precise method.

Accuracy and technical limits of percutaneous pedicle screw placement in the thoracolumbar spine

PURPOSE

The two-dimensional fluoroscopic method of percutaneous pedicle screw instrumentation has been clinically described as reliable method in the caudal thoracic and lumbosacral spine. Its accuracy has not been clearly reported in the cranial thoracic spine. The aim of this in vitro study was to investigate percutaneous pedicle screw placement accuracy according to pedicle dimensions and vertebral levels.

METHODS

Six fresh-frozen human specimens were instrumented with 216 screws from T1 to S1. Pedicle isthmus widths, heights, transversal pedicles and screws were measured on computed tomography. Pedicle cortex violation ≥ 2 mm was defined as screw malposition.

RESULTS

The narrowest pedicles were at T3-T5. A large variability between transversal pedicle axes and percutaneous pedicle screw was present, depending on the spinal level. Screw malposition rates were 36.1% in the cranial thoracic spine (T1-T6), 16.7% in the caudal thoracic spine (T7-T12), and 6.9% in the lumbosacral spine (L1-S1). The risk for screw malposition was significantly higher at cranial thoracic levels compared to caudal thoracic (p = 0.006) and lumbosacral (p < 0.0001) levels. Cortex violation ≥ 2 mm was constantly present if the pedicle width was < 4.8 mm.

CONCLUSION

Percutaneous pedicle screw placement appears safe in the caudal thoracic and lumbosacral spine. The two-dimensional fluoroscopic method has a limited reliability above T7 because of smaller pedicle dimensions, difficulties in visualizing radiographic pedicle landmarks and kyphosis.

Reduction in Traumatic Spine Injuries in the Thoracic and Lumbar Spine With Percutaneous Versus Open Dorsal Stabilization

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Doubts still remain whether a sufficient reduction of vertebral body fractures can be achieved if a percutaneous surgical approach is adopted. The aim of this retrospective cohort study was to analyze the reduction and perioperative complications using a percutaneous versus open surgical approach for dorsal stabilization.

METHODS

Patients suffering from a traumatic injury of the thoracic or lumbar spine who were treated with dorsal stabilization at our level 1 trauma center were included. From January 2007 through June 2009, only the open approach was used; from June 2009 through March 2014, only the percutaneous approach with a special reduction technique was used. Retrospectively, total reduction, perioperative and intraoperative data, and postoperative complications were analyzed.

RESULTS

Using the percutaneous (n=185) versus open surgical approach (n=91), the mean reduction over all spinal injuries was 7.7±6.6 versus 8.3±5.5 degrees, respectively. The mean operation time was 75.5±50.2 versus 71.5±41.9 minutes, respectively. There was no significant difference between the 2 treatment groups in terms of the total reduction (P=0.753) or operation time (P=0.814).After the percutaneous and open surgical approach, 7 (3.8%) and 22 (24.2%) complications were documented. Complications requiring interventions were more frequent in the open treatment group.

CONCLUSIONS

Percutaneous dorsal stabilization seems to be a good alternative to the traditional open surgical approach. The fracture's reduction is similar, whereas severe complications are reduced and the operation time is not prolonged.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Evaluation of a Three-Dimensional Printed Guide and a Polyoxymethylene Thermoplastic Regulator for Percutaneous Pedicle Screw Fixation in Patients with Thoracolumbar Fracture

BACKGROUND This study aimed to evaluate the efficacy of a porous polyoxymethylene thermoplastic regulator combined with a three-dimensional (3D) printed template to guide pedicle needle insertion in patients undergoing percutaneous pedicle screw fixation (PPSF) for thoracolumbar fracture. MATERIAL AND METHODS Forty patients were randomly divided into group A, treated using a porous polyoxymethylene thermoplastic regulator combined with a 3D printed template, and group B, who underwent conventional PPSF. Data recorded included the number of pedicle screws successfully inserted on the first attempt, the number of attempts, the time to successful needle insertion, the total time of fluoroscopy, and the duration of surgery. The Visual Analogue Scale (VAS) and the Oswestry Disability Index (ODI) scores one day before surgery, and at day 1, day 7, month 1, and month 3 after surgery were recorded. The postoperative vertebral posterior kyphotic angle (KA) and the rate of change of KA were recorded. RESULTS Group A had a significantly increased total number of successful first insertions compared with group BV (P<0.05). Postoperative VAS and ODI scores of patients in both groups were significantly lower than before surgery (P<0.05), with no significant difference between the two groups at postoperative month 1 and month 3 (P>0.05). The postoperative vertebral posterior KA decreased significantly in both groups after surgery, with no significant difference between the two groups (P>0.05). CONCLUSIONS The use of a porous polyoxymethylene thermoplastic regulator combined with a 3D printed template may improve the success of pedicle insertion in patients undergoing PPSF.

Accuracy in Percutaneous Transpedicular Screws Placement Using Biplane Radioscopy: Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review and descriptive data meta-analysis.

OBJECTIVE

The objective of this study was to appropriately establish the accuracy in the percutaneous transpedicular screws (PTS) placement using biplane radioscopy (Rx-2D).

SUMMARY OF BACKGROUND DATA

The Rx-2D is a widely-used technique for PTS as it is practical, ubiquitous, and cost-effective. However, the reported "acceptable" accuracy attained by this method is widely variable ranging between 76% and 100%.

METHODS

A systematic review was conducted to screen publications about PTS placement using Rx-2D guidance. PubMed/MEDLINE database was consulted using the search term "percutaneous pedicle screw" from 1977 to 2017. Previous meta-analysis and reference lists of the selected articles were reviewed. Accuracy values were assessed fulfilling the proposed criteria. Observational data meta-analysis was performed. Cochran's Q test was used to determine heterogeneity among data extracted from the series, which was quantified by I test. P-values≤0.05 were considered statistically significant. The results were depicted by Forest plots. Funnel plots were outlined to visualize a possible bias of publication among the selected articles.

RESULTS

In total, 27 articles were included in the analysis. Results of the accuracy were as follow, 91.5% (n=7993; 95% CI, 89.3%-93.6%) of the screws were placed purely intrapedicular, and 96.1% (n=8579; 95% CI, 94.0%-98.2%) when deviation from the pedicle was up to 2 mm.

CONCLUSIONS

This meta-analysis is the largest review of PTS placed with Rx-2D guidance reported up to date. We concluded that the procedure is a safe and reproducible technique. The key values obtained in this work set reliable references for both clinical and training outcome assessing.

Minimally invasive reduction and percutaneous posterior fixation of one-level traumatic thoraco-lumbar and lumbar spine fractures

INTRODUCTION

Although open procedures are the gold standard, the alternative approach of minimal invasive reduction using percutaneous screws for thoracic and lumbar spine fractures is under discussion. Aim of this study was to investigate the results of reduction and the accuracy of screw placement in minimally invasive percutaneous posterior instrumentation for these fractures.

MATERIALS AND METHODS

One hundred and twenty-seven patients with thoraco-lumbar and lumbar burst fractures and minimal invasive dorsal instrumentation were analyzed retrospectively in terms of the accuracy of pedicle screw placement and results of fracture reduction.

RESULTS

In total, 542 screws were placed. Thirty-four (6.3%) screws of 22 patients (17.3%) were misplaced, but misplacement was minimal, replacement of any screw position due to instability was not necessary, and no new neurological deficit occurred. In thoraco-lumbar fractures (82/64.5%), reduction succeeded from 2.5 ± 6° kyphosis to 5.6 ± 5.7° lordosis (p < 0.001) and in lumbar spine fractures from 6.9° ± 10.3° lordosis to 14.5° ± 8.8° lordosis (p < 0.001).

CONCLUSION

Minimal invasive percutaneous dorsal instrumentation of burst fractures of the thoraco-lumbar and lumbar spine provides adequate reduction and reliable regular screw placement.

LEVEL OF EVIDENCE

Level IV (retrospective series).

Radiological Results and Clinical Patient Outcome After Implantation of a Hydraulic Expandable Vertebral Body Replacement following Traumatic Vertebral Fractures in the Thoracic and Lumbar Spine: A 3-Year Follow-Up

STUDY DESIGN

A prospective monocentric study.

OBJECTIVE

The aim of the current study was the analysis of patient outcome and radiological results 3 years after implantation of a hydraulic expandable vertebral body replacement (VBR) system.

SUMMARY OF BACKGROUND DATA

Around 70% to 90% of all traumatic spinal fractures are located in the thoracic and lumbar spine. Dorso-ventral stabilization is a frequently used procedure in traumatic vertebral body fracture treatment. VBR systems can be used to bridge bony defects. In the current study, a new VBR expanded by water pressure with adjustable endplates is used.

METHODS

All patients who suffered a singular traumatic fracture to a thoracic or lumbar vertebral body (Th 5-L 5) in the period from November 2009 to December 2010 and (i) underwent dorsal instrumentation and (ii) afterwards received the implantation of a hydraulic VBR were included in this study. The clinical outcome (visual analogue scale [VAS] spine score, questionnaire) and radiological findings (sagittal angle, implant subsidence, and implant position) 3 years after implantation were analyzed.

RESULTS

The follow-up was successful for n = 47 patients (follow-up rate: 89%). Most of the patients (n = 40) were "generally/very satisfied" with their outcome. The mean rating of the VAS spine score was 65.2 ± 23.1 (range: 20.5-100.0). The analysis of the radiological data showed an average subsidence of the implants of 1.1 ± 1.2 mm (range 0.0-5.0 mm). After the initial operation, the local sagittal angle remained stable in the follow-up 3 years later both for the thoracic spine and lumbar spine. Furthermore, no change in the implant's position was observed.

CONCLUSION

The implantation of a hydraulically expandable VBR allows a permanent stable fixation after traumatic fractures of the thoracic and lumbar spine.

LEVEL OF EVIDENCE

2.

[Trisegmental fusion by vertebral body replacement : Outcome following traumatic multisegmental fractures of the thoracic and lumbar spine]

BACKGROUND

Around 5% of all trauma patients suffer from spinal trauma. Spinal fractures are mainly located in the thoracic and lumbar spine. For multisegmental vertebral fractures categorized as instable, combined dorsal instrumentation and ventral stabilization is recommended. Numerous vertebral body replacement systems are available for ventral stabilization.

OBJECTIVES

The aim of the current study was to analyze radiological results following the implantation of a hydraulic expandable vertebral body replacement and the evaluation of patients' outcome three years after implantation.

MATERIALS AND METHODS

All patients who suffered traumatic multisegmental fractures of the thoracic or lumbar spine in the period from September 2009 to September 2012 were included in this study. Patients with additional injuries or abnormal sensitivity or motor function were excluded from the current study. All patients underwent dorsal percutaneous instrumentation. Afterwards, implantation of the vertebral body replacement was performed via the mini-open approach at our level I trauma center. In the computed tomography and X‑ray imaging, the sagittal kyphotic angle was measured. Furthermore, the clinical outcome (patients' satisfaction, VAS spine score) was analyzed using a questionnaire.

RESULTS

During the above mentioned period, seven patients (four female; three male) underwent dorsal instrumentation and ventral trisegmental fusion and were identified fitting the inclusion/exclusion criteria and thus could be included in the study. Most fractures were located in the thoracic-lumbar junction and were categorized A4 according to the AO Spine classification system. The analysis of the radiological data showed a pre-operative average traumatic segmental angle of 18.1 ± 14.9°, which could be decreased by reposition procedure to 6.4 ± 1.7°. The complete follow-up, including the data three years after implantation of the vertebral body implant, was available for three patients. The traumatic segmental angle remained stable in the follow-up three years later. In one case, a subsidence of the implant of 1.5 mm was observed, having no influence on the patients' satisfaction. All three patients indicated to be very satisfied with their outcome. The VAS spine score rating was in the range between 62.4 and 70.2.

CONCLUSIONS

The current study shows that in the case of multisegmental fractures complete reposition by ligamentotaxis and by the percutaneous instrumentation system is possible. In addition to the percutaneous dorsal instrumentation, the implantation of a hydraulically expandable vertebral body replacement may allow a stable fusion after complex traumatic fractures of the thoracic and lumbar spine. Patients are very satisfied with their outcome after this procedure.