Comparison of the accuracy of cannulated pedicle screw versus conventional pedicle screw in the treatment of adolescent idiopathic scoliosis: A randomized retrospective study

Analysis of accuracy of pedicle screw placement in dysplastic pedicles in adolescent idiopathic scoliosis using the pedicle expansion technique with CT-based navigation

BACKGROUND

This study aimed to study the accuracy of pedicle screw (PS) insertion into dysplastic pedicles in adolescent idiopathic scoliosis (AIS) comparing cannulated screw using the pedicle expansion technique (PET) versus conventional technique.

METHODS

Forty-two AIS patients with 766 PSs were evaluated. In total, 236 screws were inserted into dysplastic pedicles: 138 and 98 screws were inserted using the PET (PET group) and standard technique (conventional group), respectively. Both methods used CT-based navigation to determine the insertion point. In the PET, a rigid ball tip feeler was tapped with a mallet to create an insertion route, a guide wire was passed through the tap, the pedicle was enlarged, and then a cannulated PS with a diameter of 4.35 mm was inserted. Postoperative CT was used to compare the accuracy of PS insertion.

RESULTS

In total, 23/236 (9.7%) perforations occurred. Regarding overall perforation, there were six (4.3%) and 17 (17.3%) cases in the PET and conventional group, respectively (P = 0.008). In terms of medial perforation, the PET group (n = 2, 1.4%) was significantly better than the conventional group (n = 7, 7.1%) (P = 0.021). In terms of lateral perforation, the PET group (n = 4, 2.9%) was significantly better than conventional group (n = 10, 10.2%) (P = 0.030). Only grade 1 perforation had occurred in the PET group, whereas grades 2 and 3 perforation occurred in the conventional group.

CONCLUSION

Use of the PET with CT-based navigation significantly increased the accuracy and safety of PS insertion in dysplastic pedicles in AIS.

Patient-specific guide systems decrease the major perforation rate of pedicle screw placement in comparison to the freehand technique for adolescent idiopathic scoliosis

PURPOSE

This study aimed to compare the accuracy of pedicle screw (PS) placement between a low-profile three-dimensional (3D) printed patient-specific guide system and freehand technique for adolescent idiopathic scoliosis (AIS) surgery.

METHODS

Patients with AIS who underwent surgery between 2018 and 2023 at our hospital were included in the study. The 3D-printed patient-specific guide was used since 2021 (guide group). PS perforation was classified using Rao and Neo's classification (grade 0, no violation; grade 1, < 2 mm; grade 2, 2-4 mm; grade 3, > 4 mm). Major perforations were defined as grades 2 or 3. The major perforation rate of PS, operative time, estimated blood loss (EBL), and correction rate were compared between the two groups.

RESULTS

A total of 576 PSs were inserted in 32 patients (20 patients in the freehand (FH) group and 12 patients in the guide group). The major perforation rate was significantly lower in the guide group than in the FH group (2.1% vs. 9.1%, p < 0.001). Significantly fewer major perforations were observed in the guide group than in the FH group in the upper thoracic (T2-4) region (3.2% vs. 20%, p < 0.001) and lower thoracic (T10-12) region (0% vs. 13.8%, p = 0.001). The operative time, EBL, and correction rate were equivalent between the two groups.

CONCLUSION

The 3D-printed patient-specific guide notably reduced the major perforation rate of PS without increasing EBL and operative time. Our findings indicate that this guide system is reliable and effective for AIS surgery.

Percutaneous Versus Open Pedicle Screw Fixation for Pyogenic Spondylodiscitis of the Thoracic and Lumbar Spine: Systematic Review and Meta-Analysis

STUDY DESIGN

A systematic review and meta-analysis.

OBJECTIVE

This meta-analysis aimed to compare percutaneous (PPS) versus open pedicle screw (OPS) fixation for treatment of thoracic and lumbar spondylodiscitis.

SUMMARY OF BACKGROUND DATA

Pyogenic spondylodiscitis of the thoracic and lumbar spine can produce instability, deformity, and/or neurological compromise. When medical treatment is unsuccessful, surgical treatment is indicated, with the conventional open approach the usual standard of care. However, percutaneous techniques can be advantageous in medically vulnerable patients.

MATERIALS AND METHODS

A literature search was performed using the PubMed, Web of Science, and Scopus databases, looking for comparative articles on pyogenic spondylodiscitis requiring surgical stabilization with pedicle screws. This systematic review is reported according to PRISMA guidelines.

RESULTS

From 215 articles initially identified, 7 retrospective studies were analyzed, encapsulating an overall sample of 722 patients: 405 male (56.1%) and 317 female (43.9%). The treatment modality was PPS fixation in 342 patients (47.4%) and OPS fixation in 380 (52.6%). For PPS, operating time was 29.75 minutes ( P <0.0001), blood loss 390.18 mL ( P <0.00001), postoperative pain 1.54 points ( P <0.00001), and length of stay 4.49 days ( P =0.001) less than with OPS fixation, and wound infection 7.2% ( P =0.003) less frequent. No difference in screw misplacement ( P =0.94) or loosening ( P =0.33) rates was observed.

CONCLUSION

Employing PPS fixation to treat pyogenic spondylodiscitis of the thoracic and lumbar spine is associated with significantly reduced operating time, blood loss, postoperative pain, length of stay, and rates of wound infection than OPS fixation, with no difference between the 2 treatments in rates of screw misplacement or screw loosening.

USE OF THE uCentrum SYSTEM IN THE SURGICAL TREATMENT OF DISEASES OF THE VERTEBRAL SPINE

ABSTRACT Objectives: Evaluate the treatment outcome and the performance of the uCentum spinal fixation system in treating traumatic, degenerative, and tumoral diseases of the spine. Methods: This is a therapeutic study to investigate treatment outcomes and level of evidence III, including twenty-three adult patients of both sexes undergoing surgical treatment of degenerative (13 patients), traumatic (04 patients), or tumor diseases (06 patients). Patients were prospectively evaluated using clinical parameters: pain (visual analog scale), clinical and functional assessment questionnaires (SF-36, Oswestry and Roland-Morris), and radiological criteria (arthrodesis consolidation, loosening, breakage or deformation of the implants). Results: Twenty patients were followed for a period of 01 month to 12 month (mean 6,5±7,77). Three patients died due to complications unrelated to the primary disease (traumatic brain injury, septicemia, and lung tumor). Improvements were observed in clinical parameters and scores of the evaluation questionnaires used. No implant-related complications (breakage, loosening, deformation) were observed. Conclusion: the uCentum fixation system showed great versatility for performing the surgical treatment, allowing the performance of open, percutaneous procedures, the introduction of acrylic cement inside the implants, and conversion of polyaxial screws into monoaxial screws intraoperatively. Level of Evidence III; Therapeutic Studies - Investigating the Results of Treatment.

A Comparison of Drill Guiding and Screw Guiding 3D-Printing Techniques for Intra- and Extrapedicular Screw Insertion

STUDY DESIGN

Screw randomized cadaveric study.

OBJECTIVE

To compare the accuracy of three-dimensional (3D)-printed drill guides versus additional screw guiding techniques for challenging intra- and extrapedicular screw trajectories.

SUMMARY OF BACKGROUND DATA

Pedicle screw placement can be technically demanding, especially in syndromic scoliosis with limited bone stock. Recently, 3D-printing and virtual planning technology have become available as new tools to improve pedicle screw insertion. Differences in techniques exist, while some focus on guiding the drill, others also actively guide subsequent screws insertion. The accuracy of various 3D-printing-assisted techniques has been studied; however, direct comparative studies have yet to determine whether there is a benefit of additional screw guidance.

METHODS

Two cadaveric experiments were conducted to compare drill guides with two techniques that introduce additional screw guiding. The screw guiding consisted of either k-wire cannulated screws or modular guides, which were designed to guide the screw in addition to the drill bit. Screws were inserted intra- or extrapedicular using one of each methods according to a randomization scheme. Postoperative computed tomography scanning was performed and fused with the preoperative planning for detailed 3D screw deviation analysis.

RESULTS

For intrapedicular screw trajectories malpositioning was low (2%) and the modular guides revealed a statistically significant increase of accuracy (P  = 0.05) compared with drill guides. All techniques showed accurate cervical screw insertion without breach. For the extrapedicular screw trajectories both additional screw guiding methods did not significantly (P = 0.09) improve accuracy and malpositioning rates remained high (24%).

CONCLUSIONS

In this cadaveric study it was found that the additional screw-guiding techniques are not superior to the regular 3D-printed drill guides for the technically demanding extrapedicular screw technique. For intrapedicular screw insertion, modular guides can improve insertion; however, at cervical levels regular 3D-printed drill guides already demonstrated very high accuracy and therefore there is no benefit from additional screw guiding techniques.

LEVEL OF EVIDENCE

3.

Uniplanar Cannulated Pedicle Screws in the Correction of Lenke Type 1 Adolescent Idiopathic Scoliosis

OBJECTIVE

To report the clinical use of uniplanar cannulated pedicle screws for the correction of Lenke type 1 adolescent idiopathic scoliosis (AIS), and to evalute its safety and clinical outcomes.

METHODS

A total of 68 patients with Lenke type 1 AIS were retrospective analyzed, among which 38 patients were treated with uniplanar cannulated screws at the concave side of periapical levels and multiaxial screws at the other levels (group A). The remaining 30 patients were treated with all multiaxial screws (group B). The preoperative and postoperative radiographic parameters, axial vertebral rotation, and the safety of the pedicle screws were evaluated.

RESULTS

Preoperative data were comparable between the 2 groups. The postoperative proximal thoracic curve, main thoracic curve, thoracolumbar/lumbar curve, and apical vertebral rotation were significantly improved in both groups (P < 0.05). The coronal correction rates in group A and B were 83% and 81.9% (P = 0.723). The derotation rates in group A and B were 60.8% and 43.2% (P < 0.05). The rotation classification in the group A was also better than group B. The misplacement rate in group A and B was 7.9% and 11.8% (P < 0.05), and the total misplacement rate on the concave side (11.4%) was higher than that of convex side (8.4%). On the concave side, the misplacement rate in group A and B was 9.7% and 12.3%. On the convex side, the misplacement rate in group A and B was 5.9% and 11.1% (P < 0.05).

CONCLUSIONS

Collectively, uniplanar cannulated pedicle screws could effectively increase the accuracy of pedicle screws and facilitate the derotation of the apical vertebra compared with the multiaxial pedicle screws.

Is it an asymptomatic tracheal injury or misdiagnosis in treatment of vertebral fracture: A case report

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Pedicle screws are durable and safe tools that are frequently used in the treatment of vertebral fractures.

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The most important complications of the use of pedicle screws are vascular injuries, internal organ injuries and spinal cord injuries.

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Imaging methods, navigation systems, and cannulated pedicle screws should be used more frequently to reduce visceral organ injuries in the surgery of thoracic vertebral fractures.

Introduction

Pedicle screws are durable and safe instruments frequently used to treat vertebra injuries and deformities. There is also a possibility of medulla spinalis and visceral organ injury when the pedicle screws are delivered in unsuitable positions or dimensions. In this case, the authors want to draw attention to one of the visceral organ injuries during the thoracic pedicle screw placement.

Presentation of case

A 31 years old man underwent posterior instrumentation and fusion for T4 vertebra fractures. The patient was not symptomatic in the postoperative period. Tracheal pressure was observed at the 3rd thoracic vertebra level on the second day after the operation. No complications were encountered in the 3-year follow-up of the patient, who did not accept a second surgery recommended for screw replacement.

Discussion

During surgery for thoracic vertebral fractures, the shoulder joint makes it difficult to imagine as the shoulder bones enter the field of view. Therefore, the number of misplaced screws increases. Moreover, it increases the risk of internal organ injury.

Conclusion

The use of navigation systems or cannulated pedicle screws to treat thoracic vertebral fractures reduces internal organ injuries.

Advancing spinal fusion: Interbody stabilization by in situ foaming of a chemically modified polycaprolactone

Spinal fusion (SF) surgery relies on medical hardware such as screws, cages and rods, complemented by bone graft or substitute, to stabilize the interventioned spine and achieve adequate bone ingrowth. SF is technically demanding, lengthy and expensive. Advances in material science and processing technologies, proposed herein, allowed the development of an adhesive polymeric foam with the potential to dismiss the need for invasive hardware in SF. Herein, 3D foams of polycaprolactone doped with polydopamine and polymethacrylic acid (PCL pDA pMAA) were created. For immediate bone stabilization, in situ hardening of the foam is required; therefore, a portable high-pressure device was developed to allow CO₂ foaming within bone defects. Foams were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Adhesive properties of PCL pDA pMAA outperformed PCL when tested using glass surfaces (p < 0.001) or spinal plugs (p < 0.05). No cytotoxicity was observed, and bioactivity was confirmed by the CaP layer formed upon 7 days immersion in simulated body fluid. As proof of concept, PCL pDA pMAA was extruded in-between ex vivo porcine vertebrae, and micro-computed tomography revealed similar properties to those of trabecular bone. This novel system presents great promise for instrumentation-free interbody fusion.

Comparison of the accuracy of the cannulated pedicle screw and the classical pedicle screw in the treatment of Scheuermann's kyphosis: A retrospective study

Objectives

This study aims to investigate if use of cannulated pedicle screw (CPS) in the dysplastic pedicles in Scheuermann’s kyphosis (SK) increases the accuracy rate of the screw and reduces screw-related complications.

Patients and methods

This retrospective study included 21 patients (11 males, 10 females; mean age 19.1 years; range, 13 to 22 years) (550 screws) who received correction with pedicle screws due to SK deformity between May 2015 and January 2019. Between 2017 and 2018, classical pedicle screws were used in addition to CPSs in the upper thoracic region (T2, T3, T4) and thin pedicles (group 1). However, during the years 2015 to 2016, only classical pedicle screws were used for the patients who underwent posterior instrumentation for SK (group 2). Computed tomography scanning was used to investigate the accuracy of the screws.

Results

There were 12 patients (316 screws) in group 1 and nine patients (234 screws) in group 2. Seventy-four (13.4%) of all screws were inserted incorrectly. Incorrect screw rate in group 1 was significantly lower than group 2; 21 (6.6%) and 53 (22.6%), respectively (p<0.001). There were no complications related to the use of CPSs after a mean follow-up of two-and-a-half years.

Conclusion

The use of CPS in the surgical treatment of SK does not increase the complication rate; instead it increases the accuracy of the screw. For this reason, we believe that CPS may be an effective and reliable option in the treatment of SK.