Aims

The aim of this retrospective study was to compare the correction achieved using a convex pedicle screw technique and a low implant density achieved using periapical concave-sided screws and a high implant density. We hypothesized that there would be no difference in outcome between the two techniques.

Aims

The aim of this study was to systematically compare the safety and accuracy of robot-assisted (RA) technique with conventional freehand with/without fluoroscopy-assisted (CT) pedicle screw insertion for spine disease.

Aims

Whether a combined anteroposterior fusion or a posterior-only fusion is more effective in the management of patients with Scheuermann’s kyphosis remains controversial. The aim of this study was to compare the radiological and clinical outcomes of these surgical approaches, and to evaluate the postoperative complications with the hypothesis that proximal junctional kyphosis would be more common in one-stage posterior-only fusion.

Aims

Computer-based applications are increasingly being used by orthopaedic surgeons in their clinical practice. With the integration of technology in surgery, augmented reality (AR) may become an important tool for surgeons in the future. By superimposing a digital image on a user’s view of the physical world, this technology shows great promise in orthopaedics. The aim of this review is to investigate the current and potential uses of AR in orthopaedics.

Aims

The aim of this study was to compare the outcomes of surgery using growing rods in patients with severe versus moderate early-onset scoliosis (EOS).

We reviewed 212 consecutive patients with adolescent idiopathic scoliosis who underwent posterior spinal arthrodesis using all pedicle screw instrumentation in terms of clinical, radiological and Scoliosis Research Society (SRS)-22 outcomes. In Group 1 (51 patients), the correction was performed over two rods using bilateral segmental pedicle screws. In Group 2 (161 patients), the correction was performed over one rod using unilateral segmental pedicle screws with the second ^{rod providing stability of the construct through two-level screw fixation at proximal and distal ends. The mean age at surgery was 14.8 years in both groups. Comparison between groups showed no significant differences with regard to age and Risser grade at surgery, pre- and post-operative scoliosis angle, coronal Cobb correction, length of hospital stay and SRS scores. Correction of upper thoracic curves was significantly better in Group 1 (p = 0.02). Increased surgical time and intra-operative blood loss was recorded in Group 1 (p < 0.001 and p = 0.04, respectively). The implant cost was reduced by mean 35% in Group 2 due to the lesser number of pedicle screws.}

Unilateral and bilateral pedicle screw techniques have both achieved excellent deformity correction in adolescent patients with idiopathic scoliosis, which was maintained at two-year follow-up. This has been associated with high patient satisfaction and low complication rates.

Introduction. A new triggered electromyography test for detection of stimulus diffusion to intercostal muscles of the contralateral side during thoracic pedicle screw placement was evaluated. Experimental research was carried out in order to determine if, using this test, neural contact at different aspects of the spinal cord and nerve roots could be discriminated. Methods. Nine industrial pigs (60–75 kg) had 108 pedicle screws placed bilaterally in the thoracic spine (T8–T13). Neural structures were stimulated under direct vision at different anatomic locations from T9 to T12. Recording electrodes were placed over the right and left intercostal muscles. Increasing intensity of the stimulus was applied until muscle response was detected at the contralateral side (diffusion phenomenon). After this first experiment, the thoracic spine was instrumented. Screws were placed in the pedicle in two different positions, the anatomic intrapedicular location and with purposeful contact with the neural elements. Results. Response thresholds to direct stimulation of nerve root at different points were significantly lower than those obtained by stimulation of the dorsal aspect of the spinal cord (0.44±0.22 mA vs 1.38±0.71 mA). However, a 24-fold stimulation intensity (6.50±0.29 mA) was necessary to obtain diffusion of the EMG response to the opposite left side if the right nerve root was stimulated. Only a 2-fold increment (3.17±0.93 mA) was able to elicit diffusion of EMG responses to the contralateral side when stimulation was applied to the dorsal aspect of the spinal cord. Contralateral EMG responses after high increases of stimulation thresholds indicated nerve root contact. Diffusion phenomenon after low threshold increments reflected medullar contact. Electromyography recordings after triggered stimulation of the screws showed that only screws in contact with the spinal cord had significantly lower responses (2.72±1.48 mA). Conclusion. Stimulus-triggered EMG could only discriminate screws with violation of the medial pedicle wall if they were contact with neural tissues. Recording EMG-potentials at the contralateral paraspinal muscles (stimulus diffusion phenomenon) proved to be a reliable method to discriminate which of the neural structures was at risk

Study design. Retrospective study. Objectives. To optimise the radiation doses and image quality for the cone-beam O-arm surgical imaging system in spinal surgery. Summary of Background. Neurovascular compromise has been reported following screw misplacement during thoracic pedicle screw insertion. The use of O-arm with or without navigation system during spinal surgery has been shown to lower the rate of screw misplacement. The main drawback of such imaging surgical systems is the high radiation exposure. Methods. Chest phantom and cadaveric pig spine were examined on the O-arm with different scan settings: two were recommended by the O-arm manufacturer (120 kV/320 mAs, and 120 kV/128 mAs), and three low-dose settings (80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs). The radiation doses were estimated by Monte Carlo calculations. Objective evaluation of image quality included interobserver agreement in the measurement of pedicular width in chest phantom and assessment of screw placement in cadaveric pig spine. Results. The effective dose/cm for 120 kV/320 mAs-scan was 13, 26, and 69 times higher than those delivered with 80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs-scans, respectively. Images with 60 kV/40 mAs were unreliable. Images with 80 kV/80 mAs were considered reliable with good interobserver agreement when measuring the pedicular width (random error 0.38 mm and intraclass correlation coefficient 0.979) and almost perfect agreement when evaluating the screw placement (κ-value 0.86). Conclusions. The radiation doses of the O-arm system can be reduced 5–13 times without negative impact on image quality with regard to information required for spinal surgery

Introduction. Thoracic pedicle screws have been proven to be safe and effective in the treatment of adolescent idiopathic scoliosis (AIS). However, the effect of the instrumentation alloy has not yet been investigated. We aimed to compare segmental versus non segmental thoracic pedicle screw instrumentation in patients with AIS. Methods. A consecutive series of 143 patients with AIS (Lenke classification 1–4) surgically treated from 1998 to 2005 by means of thoracic pedicle screws were retrospectively reviewed. Considering implant density (number of fixation anchors placed per available anchors sites; segmental =60% [S], non-segmental =60% [NS]) and implant alloy used (titanium [Ti] vs stainless steel [SS]) we divided the cohort into four groups: Ti-S (48 cases); Ti-NS (34 cases); SS-S (35 cases); and SS-NS (26 cases). Groups were similar for preoperative mean age, sex distribution, Risser sign, main thoracic curve, and thoracic kyphosis. Pearson correlation coefficient and univariate analysis of variance were used. Results. At a mean follow-up of 6·2 years (range 3–10) the overall final main thoracic curve correction was a mean of 61·4% (20–89), whereas the implant density within the major curve was 71% (15–100%). We recorded a significant correlation between implant density and percentage major curve correction (r=0·41, p<0·002); when the four groups were compared we noted that the SS-S group showed the greatest average correction (75%), followed by the Ti-S, SS-NS, and Ti-NS groups. We detected no significant differences between SS-S versus Ti-S versus SS-NS (r=0·002, p>0·05; r=0·13, p>0·05; r=0·07, p>0·01, respectively), whereas the Ti-NS group showed a statistically significant inferior percentage correction when compared with all other groups (average 52%; p<0·001). Nevertheless, no significant difference between groups was recorded on the SRS-30 assessment, showing a postoperative improvement in both self-image and satisfaction. Conclusions. When an SS instrumentation is used, non-segmental pedicle screw constructs seem to be equally effective as segmental instrumentations in obtaining satisfactory results in patients with main thoracic AIS. When the implant alloy used is titanium, an implant density of greater than 60% should be guaranteed so as to achieve similar results to those recorded in this study

Introduction. The use of thoracic pedicle screws for the treatment of adolescent idiopathic scoliosis (AIS) has gained widespread popularity. Many techniques has been described to increase the accuracy of free hand placement; however the placement of pedicle screws in the deformed spine poses unique challenges because of possible neurologic and vascular complications. We are describing a universal way of insertion of pedicle thoracic screws which has been applied in many pathologies including the deformed spine. Methods. Our technique includes exposure of the superior facet of the corresponding body to identify its lateral border border which together with the superior border of the TP denotes our entry point which is just lateral to this crossing, we make a short entry with a straight Lenke probe then continue the track with a strong ball probe to go safely through the cancellous bone of the body. This is retrospective review of radiographs and clinical notes of all the patients who underwent posterior thoracic instrumentation by pedicle screws using the same single technique by one surgeon between June 2008 and December 2009; 1653 screws in 167 consecutive patients (119 females and 48 males). There were 139 deformities, 130 scoliosis (AIS 80, Congenital 31, Neuromuscular 10 and Degenerative 9), 19 kyphosis and 18 other diagnoses (fractures 14, revision 3 and tumour 1). Results. The recorded complications for all the patients were: 1 patient had pain due to nerve impingement, 1 parasthesia and 1 CSF leak intraoperatively. There were no revision of any of the screws, no vascular complications. Conclusion. Thoracic pedicle screws can be inserted with a universal point of entry using the same technique in all the levels of the dorsal spine. This technique seems to be simple and safe. Ethics approval: None. Interest Statement: None

Objective. The use of all pedicle screw constructs for the management of spinal deformities has gained widespread popularity. However, the placement of pedicle screws in the deformed spine poses unique challenges for the spinal surgeon. The purpose of this study was to evaluate the complications and radiological outcomes of surgery in 124 consecutive patients with spinal deformity. These patients underwent correction of coronal and sagittal imbalance with segmental pedicle screw fixation only. Background. All pedicle screw constructs have been associated with improved correction in all three planes. In patients with severe deformity, such constructs can obviate the need for anterior surgeries, and the higher implant cost is offset by the avoidance of dual anterior and posterior approaches. Pedicle screw fixation enables enhanced correction of spinal deformities, but the technique is still not widely applied for thoracic deformities for fear of neurological complications. This is a retrospective study that was carried out on 124 patients who underwent segmental screw fixation for coronal and sagittal spinal deformities. The purpose of this study was to evaluate the complications and outcomes of this technique and also assess the evidence of enhanced correction. Material and Methods. A total of 124 consecutive patients subjected to pedicle screw fixation for spinal deformities were analysed after a minimum period of follow-up of two years. Etiologic diagnoses were idiopathic scoliosis in 32, neuromuscular scoliosis 48, Scheuermann's kyphosis in 28 and others 16. They were reviewed using the medical records and preoperative, intraoperative and postoperative radiographs. Computed tomography was performed when screw position was questionable. Deformity correction was determined on preoperative and postoperative radiographs. The positions of the screws were evaluated using intraoperative and postoperative radiographs. There were 51 male and 73 female patients with the mean age of 17.2 years (range, 10-25 years). The average cobb angle for scoliosis and kyphosis were 55°(range 45°-85°) and 72° (range 68°-100°) respectively. Results. A total of 2784 pedicle screws were inserted and 1488 screws were inserted in the thoracic spine (18 screws/patient). Screw-related neurological complications occurred in two patients 0.4%; these comprised a transient paraparesis and dural tear. Other complications comprised six intraoperative pedicle fractures, 12 screw loosening, four postoperative infections and one haemothorax. There were no significant screw-related neurological or visceral complications. The average correction was 78% for scoliosis and 51% for kyphosis. The mean estimated blood loss was 653 ml (range, 510-850), the mean operation time was 148 minutes (range, 120-220). Conclusion. We were able to demonstrate that application of pedicle screw construct is safe and advantageous in the management of spinal deformities. Significant correction has been achieved with a single stage posterior surgery in all groups. Scoliosis and kyphotic deformity corrections were 78% and 51% respectively; this is far superior to correction achieved with one stage surgery with other constructs. This study showed that improved derotation has decreased the need for thoracoplasty, thus eliminating its risk of associated morbidity. Superior control of the deformity obviated the need for an anterior approach in severe curves. Improved correction, lower morbidity and shorter hospitalisation has compensated for higher implant cost. We believe using all pedicle screw fixation is a relatively safe procedure and offers an excellent correction. This correction was maintained throughout the follow up period. Despite our safety record in thoracic pedicle screw placement, we believe this technique can be potentially dangerous in inexperienced hands, and requires a long learning curve. Therefore, a thorough anatomical knowledge of pedicle morphology, a detailed analysis of pre-operative imaging coupled with experience is essential to avoid complications. Ethics approval None. Interest Statement None

The aim of the study was to assess the safety of a novel anatomical landmark in the placement of thoracic pedicle screws. It is our clinical observation that the sagittal plane of the screw trajectory is perpendicular to the plane of the superior articular facet, when the entry point is in the lateral half of the articular surface of the corresponding superior facet. Using SECTRA software on a PACS digital imaging system, morphometric analysis was performed on thoracic vertebrae imaged using computed tomography (CT). For inclusion, the scan had to have no reported bony abnormality. It was determined whether a trajectory as described at 90 degrees to the articular facet, with an entry point just caudal to the lateral half of the facet to a depth of 25mm would breach either the medial wall of the pedicle or lateral vertebral body wall anterior to the costovertebral facet. Sixty-two CT scans (744 segments, 1488 pedicle-facet complexes) were reviewed. 1154 complexes were suitable for full analysis. Exclusions were due to the lumbarisation of the T12 facet joints (62) or inability to clearly define the facet surface due to the plane of the CT slice (272). Of 1154 entry points assessed, 1154 (100%) were safe to be entered at 90 degrees to a depth of at least 25mm. We have demonstrated the safety and reliability of a novel anatomical landmark in normal thoracic pedicles. We believe this will improve sagittal plane alignment and reduce further the risk of medial pedicle breach

Introduction: After the introduction of MRI in routine diagnostic work-up, Split cord malformations (SCM) in patients with Congenital spinal deformities (CSD) is more easily diagnosed and probably overtreated. Aim: To evaluate the necessity of neurosurgical management of SCM before corrective spinal surgery. Study Design: Retrospective case series. Patients and Methods: Thirty-two patients aged 11 years + 8 months (4–18 years) with CSDs with a follow up of 51,7+/−26,6 months were analyzed. SCM were classified as Type I(septum dividing the spinal cord and dura into two separate hemicords) and Type II(two hemicords within single dura) according to Pang. Eighteen patients with type I underwent neurosurgical intervention (spur excision and creating a single dural cuff) before corrective surgery (15 sequential and 3 simultaneous). Fourteen patients with type II were treated with posterior instrumentation without dealing with the intraspinal abnormalities. The basic maneuvers were translation, compression and shortening to realign spinal column, avoiding distraction forces and intrusion of any instrument into the spinal canal around anomalous segments. Neurological monitoring was done by the wake-up test. Results: At final follow up, scoliosis improved from 65,7+/−22 to 37+/−15 degrees (45%) in type I and from 74,3+/−21,8 to 39,4+/−18,7 degrees (47%) in type II. The correction loss was 2,3 degrees in patients with type I SCM and 2,9 degrees in patients with type II SCM. One patient with type I SCM had paraparesis resulting from a misplaced upper thoracic pedicle screws with total recovery after revision. Another patient with type I SCM who had simultaneous surgeries had deterioration of her preoperative neurological deficit only to recover partially. Two patients with type I SCM and one patient with type II SCM developed deep wound infections and needed multiple debridements. Two patients with type I SCM had dural leakage that needed repair. Conclusion: Although it is a common practice to operate all SCMs before corrective surgery in CSD, it may not be necessary in type II which can be managed safely without any neurosurgical intervention

Purpose: To introduce our new surgical technique for better correction of scoliosis and rib hump deformity. Surgical technique: The technique consists of rib mobilization (RM) and hook rotation maneuver (HRM). RM is to release costo-vertebral connection bilaterally from T5 to T10 to mobilize ribs obtaining more flexibility of the spine. HRM is to rotate convex side hooks on transverse process ventrally pushing down the ribs, thus giving derotational force while compression force is applied. Subjects: Forty-six idiopathic cases with minimum 1 year follow-up were reviewed. The average F-up period is 15.1m( 12 – 24). The average age at surgery was 20.1 y(12–57). Conventional multiple hooks, screws, wires and rod system was used. Results: The average Cobb angle was 56.0 ( 40 – 93) degrees. The average rib hump was 22.5 mm in height and 13.9 degrees by scoliometer. At 3 w post-op, 6 m post-op, and at F-up, the average Cobb angle was 13.0 (77.9%), 15.6 (73.4%), and 16.0 (72.6%, 43 – 100%)) respectively. The average rib hump at 6m post-op and at F-up was 9.7 mm in height and 6.8 degrees, and 10.3mm and 6.4 degrees respectively. The hump index at thoracic level was 5.49 pre-op, 3.73 at 6m and 4.25 at F-up. Conclusion: Our new technique improved the correction of not only scoliosis but also thoracic hump significantly. The derotational force by HRM is weaker than direct derotation by pedicle screw. However, it is undoubtedly a safer and less expensive technique than thoracic pedicle screw, providing significant correction of rib hump

Introduction: We report the result of cervical osteotomy in 11 patients using a controlled reduction technique and assess the safety and efficacy of this operation. Methods: Between 1993 and 2006, 11 patients with ankylosing spondylitis underwent correction of cervical kyphosis utilizing an extension osteotomy at the C7/T1 junction. The procedure was carried out under general anaesthesia with spinal cord monitoring. Lateral mass screws were placed from C3–C6 and thoracic pedicle screws placed from T2 to T5. After completion of the osteotomy, the reduction manoeuvre was carried out by the senior surgeon lifting the halo, while bilateral temporary malleable rods (fixed to cervical lateral mass screws) were allowed to pass through top loading thoracic pedicle screws, before tightening by the assistant when the desired position had been achieved. The temporary malleable rods were then replaced with definitive rods, thereby creating a solid internal fixation. A halo vest was maintained for 12 weeks to support the instrumentation and allow the fusion mass to develop. Results: Surgery was performed on 10 males and one female. The mean age at surgery was 56 years (range 40–74). Duration of symptoms averaged 2.7 years (range 1–5 yrs). The average duration of surgery was 4.7 hours (range 3–6.5) with a mean blood loss of 1938cc (range 1000–3600). The mean follow up was 6.5 years (range 2–13). The mean pre-op chin brow vertical angle was 54º (range 20–70) reducing to 7º (range 2–20) at final follow-up. The mean pre-operative kyphotic angle was 19.2º reducing to minus 34º at final follow up. Restoration of normal forward gaze was achieved in all cases. No patient suffered spinal cord injury or permanent nerve root palsy. Conclusion: Cervico-thoracic osteotomy is a potentially hazardous procedure. The technique described reduces the risk of translation during the reduction manoeuvre thereby reducing the risk of serious neurological injury

Study Design: A radiographic study using disarticulated cadaver thoracic vertebrae. Objective: To determine the accuracy of orthogonal X-rays in detecting thoracic pedicle screw position by different groups of observers. Summary of Background Data: Pedicle screws are increasingly being used for internal fixation of the thoracic spine. Surgeons and radiologists are often required to make decisions on the pedicle screw position by plain antero-posterior (AP) and lateral radiographs. Materials and Methods: 23 disarticulated fresh adult thoracic vertebrae were used in this study. Pedicle screws were inserted completely within the pedicle; or deliberately violating the lateral or medial cortex of the pedicle. AP and lateral radiographs of each vertebrae were assessed by 2 spine surgeons, 2 spine trainees, and 2 musculoskeletal radiologists in a sequence of AP alone, and AP + lateral views. They were supposed to cataogorize the pedicular screw as ‘out laterally’/‘inside the pedicle’/‘out medially’ or ‘unsure’. Their assessments were compared to the actual position of the screws determined by the axial views. Results: For each screw position, trend was found towards slightly better accuracy with availability of AP & lateral views in combination. From either AP alone or AP + lateral views, significantly higher accuracy was found in detecting screws “out laterally” than “inside pedicle” (p< 0.01), or “out medially”(p< 0.05), respectively. Nearly 30% of screws that were deliberately placed through the medial pedicle wall were not correctly identified. In addition, surgeons have highest accuracy from either AP alone, or AP + lateral views, followed by the spine trainees and radiologists. Radiologists provided more “unsure” answers than surgeons or trainees. Conclusions: Screws that perforated the lateral cortex were the easiest, and those that were wholly within the pedicle were the most difficult to identify correctly. The use of plain radiographs to detect thoracic pedicle screws placed through the critical medial cortex is unreliable. The positions of thoracic pedicle screws appear to be more accurately detected by AP + lateral, however, the major contribution was from AP views. Surgeon experience continues to be vitally important in the safe placement of thoracic pedicle screws. Key points:. Screws that perforated the lateral cortex were the easiest, and those that were wholly within the pedicle were the most difficult to identify correctly. The use of plain radiographs to detect thoracic pedicle screws placed through the critical medial cortex is unreliable. AP + lateral views provides higher accuracy in determining the screw position, while, the major contribution comes from AP views. Surgeon experience, in the use of tactile skills and anatomical knowledge continue to be vitally important in the safe placement of thoracic pedicle screws

Introduction: Several studies have looked at accuracy of thoracic pedicle screw placement, both in vivo and on cadavers, using fluoroscopy, image guidance, and anatomical landmarks. To our knowledge the upper thoracic spine (T1-T6) has not been specifically studied in the context of screw insertion and placement accuracy without the use of either image guidance or fluoroscopy. Our objective was to study the accuracy of placement of upper thoracic screws without the use of fluoroscopy, and report on implant related complications. Methods: A single surgeon inserted a total of 60 screws in 13 consecutive non-scoliotic spine patients. These 60 screws were the first to be placed in the high thoracic spine in our institution. All previous surgeries used only a hook or wire technique for the upper thoracic spine. The most common diagnosis in our patient population was trauma. All screws were inserted using a modified Roy-Camille technique. Post operative axial computed tomography (CT) images were obtained for each patient and analyzed by an independent senior radiologist for placement accuracy. Furthermore we reviewed the operative records of each patient to record any implant related complications. Results: No pedicle screw misplacements were found in 61.5% of the patients. Fifty three out of the 60 screws were placed correctly within all the pedicle margins. The overall pedicle screw placement accuracy was 88.3% using our modified Roy-Camille technique. Five medial and 2 lateral violations were noted in the 7 misplaced screws. One of the 7 misplaced screws was considered to be a marginal violation. No implant related complications were noted. Furthermore, no learning curve effect was noted as far as misplacement pattern was concerned. Conclusion: We found that inserting pedicle screws in the upper thoracic spine based solely on anatomical landmarks was safe with an accuracy comparable to that of published studies on image guided surgery at the thoracic level

Purpose: We describe a technique using orthoganol imaging on a radiolucent table that allows reliable, safe and reproducible insertion of thoracic pedicle screws. Method: The popularity of pedicle screws for spinal fixation in deformity surgery has increased. Studies have shown lumbar pedicle screws to be safe and effective. The biomechanical superiority of pedicle screws has also been demonstrated. Nonetheless, reluctance to apply the technique to thoracic vertebra remains, most likely because of perceived technical difficulties and a reported high complication rate. We describe a technique using orthoganol imaging on a radiolucent table, used in a series of patients in whom we have inserted a total of over 2000 screws. Results: We have inserted over 2000 thoracic pedicle screws without neurological injury. In addition, this technique has allowed us to use pedicle screw to the exclusion of other, less mechanically favourable, methods of fixation to the spine; over the same time period we used only three sublaminar hooks. Furthermore, the lateral to medial or ‘toeing in’ of screw placement gives greater pull out strength to each screw by increasing the ‘volume’ of bone that has to be overcome before failure by pull out occurs. In addition this trangulation technique allows insertion of :screws of greater diameter than the pedicle and decreases the chance of broaching medially. Conclusion: Using the technique described, we achieve accurate screw placement ‘first time, every time’, giving us a biomechanically superior construct, allowing more powerful derotation of the spine and thus greater correction of deformity. We recommend its use for all thoracic pedicle screws

The main health care gain in the correction of idiopathic scoliosis is cosmetic. Debate exists regarding the optimum implant method of fixation. The use of pedicle screws is the thoracic spine is common. Complications of implant placement are reported less frequently than they occur. The late development of neurological complications has not been reported before and the scoliosis society members need to be aware of the risk specifi-cally associated with increased kyphosis at the cranial end of the fusion. A 33 year old female underwent correction of a 72 degree right thoracic scoliosis. Pedicle screws were used and a costoplasty undertaken. Cord monitoring was satisfactory and there were no neurological symptoms or signs in the postoperative period. At six week review the patient was very pleased with the cosmetic improvement. At 8 weeks post operatively the patient became aware of a weakness in the right foot, at 10 weeks an early review was requested for what was thought to be a drop foot. In clinic at 11 weeks post op there was a sensory level at T5 with paretic gait and weakness grade 3 of the right leg. Imaging revealed an increase in the upper thoracic kyphosis and the upper right screw was confirmed as impinging on cord with MRI and CT. The screw was removed immediately and a rapid recovery occurred. Late complications of pedicle screws are not commonly reported. The upper thoracic spine may be a specific area of increased risk

A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. The purpose of this study was to determine the accuracy of placement and safety of pedicle screws in open reduction of unstable thoracic spine fractures. The surgeries were performed by one of five fellowship trained spinal surgeons. CT scans were formed on twenty-three patients totaling two hundred screws using 3mm cuts. Three independent reviewers assessed and categorized the screw position as within the pedicle or as a violation of the pedicle wall. 98% of the screws were accurate and we recommend the use of pedicle screws in thoracic fractures . A prospective cohort outcome evaluation of unstable thoracic spine fractures treated with posterior pedicle screw fixation. This study is to determine the accuracy of placement, safety of pedicle screws in open reduction of unstable thoracic spine fracture. Surgery was performed by one of five fellowship trained spine surgeons. CT scans were performed on twenty-three patients using 3mm cuts in both sagittal and transverse planes. Pedicle screw position was assessed by three independent reviewers. Screw position was categorized as within the wall of the pedicle or in violation of the wall. Further sub-classification of pedicle wall violation reviewed the direction and distance of perforation. Independent perioperative and postoperative surveillance for complications was done. Twenty-three unstable thoracic spine fractures treated with two hundred posterior pedicle screws were analyzed. The pedicle screws spanned from T1-T12 with the majority of screws in the mid-thoracic region. Of the two hundred thoracic pedicle screws placed, 70% were fully contained within the pedicle wall. The remaining screws were deemed “out” with cortical perforation (30%). Of these, 20% were lateral perforations, 5% were medial perforations and 5% were anterolateral perforations. No superior, inferior, or anteromedial perforations were found. There was no regional area variation in incidence of perforations. 10% of all perforations were directly related to pedicle diameter to screw diameter mismatch. There were no adverse neurological, vascular, or visceral injuries detected intraoperatively or postoperatively. Surgical management of unstable thoracic spine fractures with posterior pedicle screw fixation is safe. 98% of screws had satisfactory accuracy. Although very minor misplacement of pedicle screws occurred, there were no complications and we recommend the use of pedicle screws in thoracic fractures