Thoracic Pedicle Screw Fixation Research Articles

Comparative study on the accuracy, safety and clinical effect of CT navigation and traditional open screw placement in the Treatment of Thoracic Fracture.

To explore the accuracy, safety and clinical effect of descending thoracic pedicle screw fixation assisted by computer CT three-dimensional navigation in the treatment of single segmental compression thoracic fracture. This study was a retrospective analysis. From June 2020 to June 2022, eighty patients with thoracic vertebral fractures admitted to Affiliated Hospital of Beihua University were were divided into observation group and control group according to different methods of screw placement, with 40 cases in each group. The navigation system was used to insert pedicle screws, and the control group used traditional open X-ray to insert pedicle screws by hand. Further comparison was carried out in terms of the operation time, intraoperative blood loss, perioperative complications, accuracy and safety rate of screw placement, and vertebral compression ratio between both the groups. The average intraoperative blood loss in the observation group was significantly less than the control group, the average screw insertion time was significantly shorter than the control group, the postoperative average vertebral body compression ratios was significantly better than the control group, the excellent rate of screw insertion was better than the control group, while the incidence of complications was lower than the control group, and the difference was statistically significant (all P<0.05). Intraoperative CT navigation for pedicle screw placement can reduce the time of screw placement and intraoperative blood loss, improve the excellent rate of screw placement and the compression ratio of the anterior edge of the injured vertebra, the complication rate was low.

Learning curve of thoracic pedicle screw fixation by freehand technique

Background: The freehand method of inserting thoracic pedicle screw has become one of the most popular techniques; however, data on its learning curve are scanty. The purpose of this study was to delineate the learning curve and to evaluate the safety of freehand technique of thoracic pedicle screw placement in nondeformed spine. Materials and Methods: A total of 92 consecutive patients who underwent thoracic posterior stabilization with pedicle screws using freehand technique between 2012 and 2017 in various pathologies of nondeformed spine from T1 to T10 at a single institution by a single surgeon were analyzed. Patients were divided into four quartiles (Q1, Q2, Q3, Q4, with 23 patients each) with each consecutive group serving as control for its prior. Demographics (age, sex, pathology involved) and complications were evaluated. Postoperative computed tomography (CT) scan was taken for evaluation of screws perforation including level, direction, grade, and severity of perforation. Results: Of total of 735 screws inserted in 92 patients, 72 screws were perforated with a perforation rate of 9.79%. Of the total perforations, more than half (63.88%) were of Grade 2 and maximum perforations were seen in the lateral direction (58.3%). Total three critical perforations were noted but none of them were symptomatic. The highest rate of perforation was evident at T4 vertebra (18.29%), whereas it was lowest at T9 (3.79%). The perforation rate showed a statistically significant (P < 0.05) decline in Q2 as compared to Q1 achieving asymptote in Q1 after approximately 80–100 screws. Conclusion: A steep learning curve is associated with the freehand technique of thoracic pedicle screws and asymptote can be achieved after approximately 80–100 screws. Novice surgeons can reduce the learning curve by doing practice on saw bone models and cadaveric dissection learning to avoid perforations and other complications with understanding the complex anatomy and variations encountered in the typical thoracic spine.

Upper Thoracic Spine Fractures Outcomes and Complications in King Abdul-Aziz Medical City, Riyadh

Introduction: Upper thoracic spine fractures (T1-T6) are not uncommon. They are often high-energy injuries complicated by multiple life-threatening comorbidities. There is a controversial discussion in the literature regarding the treatment choices. Thoracic pedicle screw fixation has replaced all other fixation techniques for its success rate and safety. Despite the number of studies discussing upper thoracic spine fractures, data on literature reporting postoperative complications are deficient. The aim of the study was to assess, in a series of patients, the impact of traumatic upper thoracic fractures on sagittal alignment, the incidence of possible complications, and the effect of associated injuries.&#x0D; Methodology: This retrospective chart review study included all adult cases diagnosed as traumatic upper thoracic spine fractures in KAMC in Riyadh. Data were obtained from the computerized database. The information reviewed included fracture characteristics, associated injuries, pre- and postoperative neurological status and sagittal alignment, follow-up duration, and the presence of complications.&#x0D; Result: A total of 19 patients were included in the study. Of them, 17 (89.5%) were injured secondary to a motor vehicle accident. There were three patients with a fixation level crossing the CT junction, more blood loss and procedure time was noticed with these cases. There was a notable improvement in upper thoracic kyphosis by 9º when measuring pre- and postop fracture Cobb's angle. The mean preop angle was 28.98 and the mean postop was 20.76. Of all the 19 cases involved in the study, 3 patients had developed surgical site infection as a complication. No other complication was reviewed.&#x0D; Conclusion: It is well-known in the literature that the correction of kyphosis and the absence of residual deformity postoperatively are indicators of the success and safety of the procedure used. Our findings correspond to the literature discussion that the current practice in managing traumatic upper thoracic spine fracture in KAMC in Riyadh is relatively safe and effective. Yet, further studies are needed to elaborate more on the relationship between the presence of other injuries and patients’ factors and postoperative outcomes.

CHÈN ÉP TỦY NGỰC DO U TẠO MÁU NGOÀI TỦY XƯƠNG Ở NGƯỜI BỆNH THALASSEMIA: BÁO CÁO 2 CA LÂM SÀNG VÀ NHÌN LẠI Y VĂN

The hematopoiesis occurs normally in marrow of the bones in adult human bodies. The extramedullary hematopoiesis (EMH) refers to hematopoiesis outside the medullar of the bones. This process can be a normal physiology of hematopoiesis system or a consequence of several diseases such as thalassemia, hereditary spherocytosis, myelofibrosis… The definitive diagnosis was based on thoracic spine MRI and confirmed by post-operative biopsy. Thoracic extramedullary hematopoiesis represents as a rare phenomenon complicating several chronic hemopathies. This diagnosis should be born in mind in case of spinal cord compression masses in a patient with chronic hemolytic anemia in order to avoid dangerous surgical interventions. Even though there are many methods used to deal with those complication such as surgery, radiotherapy, transfusion, cytostatic agents, or a combination of these modalities, the treatment choice has been largely uncontroversial. Here in we report 2 cases of extramedullary hematopoiesis presented with chronic anemia associated with spinal cord compression signs corresponding with thoracic spine magnetic resonance imaging. Two patients in the report who underwent thoracic pedicle screw fixation and spinal cord decompression as the main treatment showed the good clinical outcomes in short-term follow-up. Keywords: thoracic extramedullary hematopoiesis, thoracic cord compression, chronic anemia.

Clinical application of three-dimensional printing technique combined with thoracic pedicle screw track detector in thoracic pedicle screw placement

To investigate the clinical application of three-dimensional (3D) printing technique combined with a new type of thoracic pedicle screw track detector in thoracic pedicle screw placement. According to the characteristics of thoracic pedicle and common clinical screw placement methods, a new type of thoracic pedicle screw track detector was independently developed and designed. The clinical data of 30 patients with thoracic vertebrae related diseases who underwent posterior thoracic pedicle screw fixation between March 2017 and January 2020 were retrospectively analysed. Among them, there were 18 males and 12 females with an average age of 56.3 years (range, 32-76 years). There was 1 case of thoracic disc herniation, 4 cases of thoracic canal stenosis, 2 cases of ossification of posterior longitudinal ligament of thoracic vertebra, 16 cases of thoracic trauma, 2 cases of thoracic infection, and 5 cases of thoracic canal occupation. Three-dimensional CT of the thoracic vertebra was routinely performed preoperatively, and the model of the patient's thoracic vertebra was reconstructed and printed out. With the assistance of the model, preoperative simulation was performed with the combination of the new type thoracic pedicle screw track detector, and detected no nails after critical cortical damage. During operation, one side was randomly selected to use traditional hand screws placement (control group), and the other side was selected to use 3D printing technique combined with new type thoracic pedicle screw track detector to assist thoracic pedicle screws placement (observation group). The single screw placement time, adjustment times of single screw, and blood loss during screw placement were compared between the two groups. The accuracy of screw placement in the two groups was evaluated according to postoperative CT imaging data. The single screw placement time, adjustment times of single screw, and blood loss during screw placement in the observation group were significantly less than those in the control group ( P<0.05). Postoperative CT examination showed that the observation group had 87 screws of grade 1, 3 screws of grade 2, and the acceptable screw placement rate was 100% (90/90); the control group had 76 screws of grade 1, 2 screws of grade 2, 11 screws of grade 3, and 1 screw of grade 4, and the acceptable screw placement rate was 86.7% (78/90); showing significant difference in screw placement between the two groups ( χ 2=12.875, P=0.001). All patients were followed up 6-18 months, with an average of 11.3 months. There was no complication of vascular, nerve, spinal cord, or visceral injury, and screws or rods broken, and no patient was revised. The 3D printing technique combined with the new type of thoracic pedicle screw track detector assisted thoracic pedicle screw placement is convenient, and significantly improves the accuracy and safety of intraoperative screw placement, and overall success rate of the surgery.

Robotic Assistance for Minimally Invasive Cervical Pedicle Instrumentation: Report on Feasibility and Safety

Accurate screw placement remains challenging, especially in the cervical spine. We present our first experience of minimally invasive posterior cervical and upper thoracic pedicle screw fixation in the lower cervical spine. This study reports a case series of patients, undergoing posterior percutaneous pedicle fixation using Cirq robotic assistance coupled to the Airo intraoperative computed tomography scan and Brainlab navigation system. Routine computed tomography was performed on postoperative day 2 to evaluate pedicle screw placement. The effective dose was calculated. Between February 2020 and December 2020, 7 patients (4 men and 3 women) were treated. The mean age was 58.8 years (range, 29-75 years). Fixation was performed with a cannulated PASS OCT Reconstruction System (Medicrea). Overall, 28 screws were placed within cervical and upper thoracic pedicles. According to the Neo and Heary classification, 85.7% were rated as acceptable and 14.3% as poor. The radiation dose received by the patient was 9.1 mSv (range, 7.7-10.6 mSv). The radiation dose received by the surgical staff was 0 mSv. The postoperative course was excellent. Posterior miniopen fixation using Cirq robotic assistance coupled with an intraoperative computed tomography navigation system is a major innovation that can improve the accuracy of pedicle screw positioning, with acceptable patient radiation and reduced surgical team exposure.

Clinical application of vertebral arch-transverse pathway in pedicle screw implantation

To investigate the safety and effectiveness of pedicle screw implantation via vertebral arch-transverse pathway in clinical application by a prospective randomized controlled trial. Twenty-four patients who were admitted between May 2015 and June 2017 and met the selection criteria for thoracic pedicle screw fixation were included in the study. According to the random number table method, they were divided into the trial group (screw implantation via vertebral arch-transverse pathway) and the control group (traditional screw implantation technology), with 12 patients in each group. There was no significant difference between the two groups in age, gender, cause of injury, injured segment, and the interval between injury and operation (P>0.05). The time of screw implantation was recorded and compared between the two groups. The acceptable rate of screw implantation and the penetration rate of pedicle wall were calculated after operation. The time of screw implantation of trial group was (5.08±1.74) minutes, which was significantly shorter than that of control group [(5.92±1.66) minutes], and the difference was significant (t=4.258, P=0.023). Patients in both groups were followed up 1-2 years, with an average of 1.5 years. During the follow-up, no failure of internal fixation occurred. At 1 week after operation, the screw implantation in trial group was rated as gradeⅠin 54 screws, gradeⅡ in 3 screws, and grade Ⅲ in 2 screws, with the acceptable rate of 93.61%. The screw implantation in control group was rated as gradeⅠin 40 screws, grade Ⅱin 10 screws, grade Ⅲ in 8 screws, and grade Ⅳ in 1 screw, with the acceptable rate of 84.75%. There was significant difference in the acceptable rate of screw implantation between the two groups (χ2=3.875, P=0.037). The penetration rate of pedicle wall in trial group was 8.47% (5/59), which was significantly lower than that in the control group [32.20% (19/59); χ2=4.125, P=0.021]. Compared with the traditional technique, the pedicle screw implantation via vertebral arch-transverse pathway can obtain a good position of the screw canal with higher accuracy and simpler operation.

The Feasibility of Long-Segment Fluoroscopy-guided Percutaneous Thoracic Spine Pedicle Screw Fixation, and the Outcome at Two-year Follow-up.

Introduction: Posterior percutaneous instrumentation may represent a challenge when multiple levels need to be instrumentated, especially when including the upper thoracic spine. The aim of the present study was to evaluate the technical feasibility and the long-term outcome of such long constructs in different surgical conditions.Materials and Methods: This investigation was a retrospective cohort study which included patients who underwent thoraco-lumbar percutaneous fixations. We collected clinical, surgical and radiological data, with a minimum follow-up of 24 months. Health-related quality-of-life, residual pain, instrumentation placement, and complications were studied.Results: A total of 18 procedures were enrolled, in which 182 screws were implanted, (170 positioned in thoracic and 12 in lumbar pedicles, respectively). No surgical complications or hardware failure occurred in our series, 6 out of 182 (3,2%) screws had a partial pedicle breach, without neurological impairment or need for surgical revision.Conclusion: According to our results, a fully posterior percutaneous approach for long thoraco-lumbar spine instrumentation can be considered safe and reproducible, although an adequate training is strictly required.

Surgical Treatment With Thoracic Pedicle Screw Fixation of Vertebral Osteomyelitis With Long-Term Follow-up.

While recent data has demonstrated the utility of lumbar pedicle screws for the treatment of vertebral osteomyelitis, the data are limited for thoracic pedicle screws. To investigate the effectiveness of thoracic pedicle screws for the surgical treatment of vertebral osteomyelitis. A retrospective review of all operations performed by 2 spinal neurosurgeons from 1999 to 2012 yielded 30 cases of vertebral osteomyelitis that were treated with thoracic pedicle screws. Sixteen (53%) of which underwent combined anterior and posterior fusion and 14 patients (47%) underwent standalone posterior fusion. Postoperative records were analyzed for pertinent clinical, laboratory, and radiographic data. Of the 30 patients, 21 were males (70%), 8 were females (27%), and 1 was transsexual (3%). The mean age was 47 yr (range 18-69). The most common organism cultured was Staphylococcus aureus in 12 cases (50%). The mean patient stay in the hospital was 12.4 d after surgery (range 5-38 d). The mean antibiotic duration after discharge was 8 wk (range 1-24 wk). Of the 25 patients with long-term follow-up (mean, 49 mo), 92% had improved back pain (6/25 marked improvement, 17/25 complete resolution), 83% had improved muscle weakness (8/18 marked improvement, 7/18 complete resolution), and 100% had improved urinary incontinence (3/8 marked improvement, 5/8 complete resolution). Two patients (7%) required additional surgical revision due to instrumentation failure or wound infection. This study demonstrates the efficacy of utilizing thoracic pedicle screws as a primary intervention to treat vertebral osteomyelitis.

Effectiveness of the Thoracic Pedicle Screw Placement Using the Virtual Surgical Training System: A Cadaver Study.

The virtual simulation surgery has initially exhibited its promising potentials in neurosurgery training. To evaluate effectiveness of the Virtual Surgical Training System (VSTS) on novice residents placing thoracic pedicle screws in a cadaver study. A total of 10 inexperienced residents participated in this study and were randomly assigned to 2 groups. The group using VSTS to learn thoracic pedicle screw fixation was the simulation training (ST) group and the group receiving an introductory teaching session was the control group. Ten fresh adult spine specimens including 6 males and 4 females with a mean age of 58.5 yr (range: 33-72) were collected and randomly allocated to the 2 groups. After exposing anatomic structures of thoracic spine, the bilateral pedicle screw placement of T6-T12 was performed on each cadaver specimen. The postoperative computed tomography scan was performed on each spine specimen, and experienced observers independently reviewed the placement of the pedicle screws to assess the incidence of pedicle breach. The screw penetration rates of the ST group (7.14%) was significantly lower in comparison to the control group (30%, P<.05). Statistically significant difference in acceptable rates of screws also occurred between the ST (100%) and control (92.86%) group (P<.05). In addition, the average screw penetration distance in control group (2.37 mm±0.23 mm) was significantly greater than ST group (1.23 mm±0.56 mm, P<.05). The virtual reality surgical training of thoracic pedicle screw instrumentation effectively improves surgical performance of novice residents compared to those with traditional teaching method, and can help new beginners to master the surgical technique within shortest period of time.

Adjacent-segment disease after thoracic pedicle screw fixation.

OBJECTIVE Pedicle screw fixation is a technique widely used to treat conditions ranging from spine deformity to fracture stabilization. Pedicle screws have been used traditionally in the lumbar spine; however, they are now being used with increasing frequency in the thoracic spine as a more favorable alternative to hooks, wires, or cables. Although safety concerns, such as the incidence of adjacent-segment disease (ASD) after cervical and lumbar fusions, have been reported, such issues in the thoracic spine have yet to be addressed thoroughly. Here, the authors review the literature on ASD after thoracic pedicle screw fixation and report their own experience specifically involving the use of pedicle screws in the thoracic spine. METHODS Select references from online databases, such as PubMed (provided by the US National Library of Medicine at the National Institutes of Health), were used to survey the literature concerning ASD after thoracic pedicle screw fixation. To include the authors' experience at Rutgers New Jersey Medical School, a retrospective review of a prospectively maintained database was performed to determine the incidence of complications over a 13-year period in 123 consecutive adult patients who underwent thoracic pedicle screw fixation. Children, pregnant or lactating women, and prisoners were excluded from the review. By comparing preoperative and postoperative radiographic images, the occurrence of thoracic ASD and disease within the surgical construct was determined. RESULTS Definitive radiographic fusion was detected in 115 (93.5%) patients. Seven incidences of instrumentation failure and 8 lucencies surrounding the screws were observed. One patient was observed to have ASD of the thoracic spine. The mean follow-up duration was 50 months. CONCLUSIONS This long-term radiographic evaluation revealed the use of pedicle screws for thoracic fixation to be an effective stabilization modality. In particular, ASD seems to be less of a problem in the relatively immobile thoracic spine than in the more mobile cervical and lumbar spines.

How to Deal With Cerebrospinal Fluid Leak During Pedicle Screw Fixation in Spinal Deformities Surgery With Intraoperative Neuromonitoring Change

A retrospective study. To analyze the cerebrospinal fluid (CSF) leak during the thoracic pedicle screw fixation in spinal deformities, the relative intraoperative neuromonitoring changes and the strategy for management. CSF leak may occur during the preparation of trajectory of thoracic pedicle screws in scoliosis surgery. The strategy for management of such situation is controversial. There is limited literature about the CSF leak and concomitant neuromonitoring change. A total of 695 patients with spinal deformity subjected to correction by posterior instrumentation using thoracic pedicle screw fixation from 2008 January to 2010 December and followed up for more than 2 years were retrospectively analyzed for CSF leak during pedicle screw placement and the concomitant neuromonitoring changes. The cases with CSF leak and with complete information about neuromonitoring were reviewed. A total of 7284 thoracic pedicle screws were inserted in the thoracic level (10.4 screws/patient). All the procedures were performed under the intraoperative neuromonitoring. There were 8 cases of CSF leak with the rate of 0.11% during the screw trajectory preparation. Seven of the screws located at the concave side. Five cases presented with concomitant positive intraoperative neuromonitoring changes. The holes were sealed for 3 of them, and patients presented with reversible monitoring changes and intact neurological function. Negligence of the CSF leak and screw insertion caused the deterioration of neuromonitoring even neurological deficit that needed revision surgery. Three cases presented without intraoperative monitoring changes and woke up without neurological deficit. The factors impacting the safety of screw placement for CSF leak included screw position, segment of vertebra, and concomitant neuromonitoring changes. Commonly, it was not necessary to repair the dural tear and sealing the pedicle hole with bone wax for the case with reversible neuromonitoring changes was all that needed. A lateral entry point to the initial one could be used and to continue the screw placement when neuromonitoring demonstrate reversible positive changes. 4.

Mid-term results of computer-assisted cervical pedicle screw fixation.

Study DesignA retrospective study.PurposeThe present study aimed to evaluate mid-term results of cervical pedicle screw (CPS) fixation for cervical instability.Overview of LiteratureCPS fixation has widely used in the treatment of cervical spinal instability from various causes; however, there are few reports on mid-term surgical results of CPS fixation.MethodsRecord of 19 patients who underwent cervical and/or upper thoracic (C2-T1) pedicle screw fixation for cervical instability was reviewed. The mean observation period was 90.2 months. Evaluated items included Japanese Orthopaedic Association (JOA) score and C2-7 lordotic angle before surgery and at 5 years after surgery. Postoperative computerized tomography was used to determine the accuracy of screw placement. Visual analog scale (VAS) for neck pain and radiological evidence of adjacent segment degeneration (ASD) at the 5-year follow-up were also evaluated.ResultsMean JOA score was significantly improved from 9.0 points before surgery to 12.8 at 5 years after surgery (p=0.001). The C2-7 lordotic angle of the neutral position improved from 6.4° to 7.8° at 5 years after surgery, but this was not significant. The major perforation rate was 5.0%. There were no clinically significant complications such as vertebral artery injury, spinal cord injury, or nerve root injury caused by any screw perforation. Mean VAS for neck pain was 49.4 at 5 years after surgery. The rate of ASD was 21.1%.ConclusionsOur mid-term results showed that CPS fixation was useful for treating cervical instability. Severe complications were prevented with the assistance of a computed tomography-based navigation system.

Free Hand Pedicle Screw Placement in the Thoracic Spine without Any Radiographic Guidance : Technical Note, a Cadaveric Study

Thoracic pedicle screw fixation techniques are still controversial for thoracic deformities because of possible complications including neurologic deficit. Methods to aid the surgeon in appropriate screw placement have included the use of intraoperative fluoroscopy and/or radiography as well as image-guided techniques. We describe our technique for free hand pedicle screw placement in the thoracic spine without any radiographic guidance and present the results of pedicle screw placement analyzed by computed tomographic scan in two human cadavers. This free hand technique of thoracic pedicle screw placement performed in a step-wise, consistent, and compulsive manner is an accurate, reliable, and safe method of insertion to treat a variety of spinal disorders, including spinal deformity.

Modern scoliosis techniques: the use of thoracic pedicle screws for the correction of spinal deformity

The surgical treatment of scoliosis continues to evolve from its infancy in the late 1950s with Harrington rod instrumentation to the segmental thoracic pedicle screw constructs that are now being used. Thoracic pedicle screw fixation provides true segmental correction but also has some inherent disadvantages. Ideally, scoliosis treatment should correct sagittal, coronal and transverse or axial planes with rigid fixation minimizing fusion levels. The primary advantage of thoracic pedicle screws when compared with other constructs appears to be improved coronal correction, decreased pseudarthrosis rates, lower implant failure rates, three-column fixation, and the ability to correct the scoliotic deformity in all three planes. Potential disadvantages of all thoracic screw constructs involve the lordosing effect of posterior instrumentation systems that may significantly decrease thoracic kyphosis. Multiple screw placement techniques range from an all free-hand technique to image guidance. The free-hand technique with a straight-forward trajectory has been shown to have favorable pullout strength and insertional torque compared with the anatomic technique. Recent literature also has demonstrated that thoracic pedicle screws are so effective that they may replace the need for anterior surgery in adult scoliosis surgery. With proper technique placement, thoracic pedicle screws are safe and can provide maximal clinical efficacy. A review of thoracic pedicle anatomy, surgical techniques and segmental fixation constructs is provided in this review.

The safety of pedicle screw fixation in the thoracic spine

Thoracic pedicle screw fixation has many advantages over other methods of spinal fixation in treating various conditions. We evaluated the safety and efficacy of pedicle screw fixation in the thoracic spine. We retrospectively reviewed 144 patients (65 males, 79 females; mean age 38 years; range 9 to 82 years) who underwent posterior thoracic pedicle screw instrumentation. A total of 827 thoracic pedicle screws were inserted to the thoracic spine (T1-12) by the same senior spine surgeon using the free-hand technique. Indications for thoracic spine surgery were deformities (n=47, 32.6%), metastatic or primary tumors (n=15, 10.4%), spinal infections (n=7, 4.9%), degenerative diseases (n=13, 9%), and spinal trauma (n=62, 43.1%). Screw containment was assessed by three independent reviewers on postoperative plain radiographs. In addition, thin-slice computed tomography scans were obtained in 21 suspected cases (29 screws). Screw containment was found in 94.3% (780 screws). Incorrect screw placement was found in 47 screws (5.7%), including 31 screws (3.8%) demonstrated by plain radiographs, and 16 screws (1.9%) demonstrated by thin-slice computed tomography scans. More than half of the faulty screws (n=24, 51.1%) were detected in scoliosis patients, especially on the concave side of the curvature (83.3%). The most frequent site of faulty screw placement was the T8 level (21.3%). No symptoms or complications occurred related to faulty screw placement. The high accuracy of thoracic pedicle screw placement (94.3%) using the free-hand technique suggests that pedicle screw fixation of the thoracic spine is safe, reliable, and useful in the treatment of all types of spinal diseases.

Usefulness of Nutrient Foramen of Lamina for Insertion of Thoracic Pedicle Screw

Purpose : To determine the utility of the nutrient foramen on the lamina in thoracic pedicle screw fixation. Materials and Methods : This study investigated the nutrient foramina on the lamina from 4th to 8th thoracic vertebra after partial laminectomy of 7 cadaveric spines. A 2 mm steinmann pin was inserted as follows: Vertical insertion on the right nutrient foramen and a 10 degree caudad on the left nutrient foramen. Radiographs and CT were obtained and the relationships between steinmann pin and pedicle were analyzed. Results : There were 44 nutrient foramens (63%). Among them, 31 nutrient foramens (70%, 31/44) were on the right. On the lateral radiograph, the right pins were inserted to the upper end plate and the left pins were inserted within the vertebral body in T4 and T5. In T6, 7 and 8, the right pins were inserted lower than the upper end plate, and the left pins were inserted to the lower portion of the vertebral body. On the CT axial scan, medialization to 17 degrees from T4 to T7 and 5 degrees in T8 from the nutrient foramen was possible when the size of pedicle screw for humans is considered. Conclusion : The nutrient foramens on the lamina of thoracic vertebra are useful for inserting the thoracic pedicle screw.

Correction of Adolescent Idiopathic Scoliosis Using Thoracic Pedicle Screw Fixation Versus Hook Constructs

This retrospective study was undertaken to determine the effectiveness and cost of thoracic pedicle screws versus laminar and pedicle hooks in patients undergoing surgical correction of adolescent idiopathic scoliosis (AIS). Immediate preoperative and 6-week postoperative radiographs were examined in 25 consecutive cases of children with AIS who were divided into two groups, those with thoracic pedicle screw constructs and those with thoracic hook constructs. Endpoints collected included radiographic measures, complications, surgical time, implant cost, and quality-of-life measures. Ten children underwent spinal fusion using thoracic pedicle screw fixation and 15 underwent thoracic constructs composed of hooks. Similar sex and age distribution were noted in both groups, and among the 20 girls and 5 boys the average age was 14.5. The mean preoperative Cobb angle was 53.5 degrees for the screw group and 52.5 degrees for the hook group. Correction averaged 70.2% for the screw group and 68.1% for the hook group. There were no significant differences between the two patient groups in terms of percentage of or absolute curve change after surgery. The apical vertebral translation, end vertebral tilt angle, and coronal balance did not differ significantly between the two patient groups. Comparison of operative time and quality of life revealed no significant differences. Screw constructs were significantly more expensive than hook constructs. The correction obtained from thoracic pedicle screw fixation is comparable to traditional hook constructs in AIS. Surgery using either construct effectively corrects AIS.

9:43 210. Correction of adolescent idiopathic scoliosis using thoracic pedicle screw fixation vs. traditional hook constructs: a single surgeon retrospective review

BACKGROUND CONTEXT: Although hook constructs remain the gold standard for the treatment of adolescent idiopathic scoliosis, pedicle screws may offer advantages in the correction of spinal deformity. The technique is not widely applied for thoracic deformities for fear of neurologic complications. The increased cost of pedicle screw fixation may be offset by shorter operative time, blood loss, and hospital stay.

108. Rod contouring and direct vertebral rotation using thoracic pedicle screw fixation enhances 3d correction compared to rod rotation with hooks in idiopathic scoliosis at 8 years follow up

BACKGROUND CONTEXT: At our institution thoracic pedicle screws were first used in adult curves in 1987 and in adolescent curves in 1990 in conjunction with in-situ rod contouring and direct vertebral rotation techniques.