The Defects Genome of Janus Transition Metal Dichalcogenides.

2D Janus Transition Metal Dichalcogenides (TMDs) have attracted much interest due to their exciting quantum properties arising from their unique two-faced structure, broken-mirror symmetry, and consequent colossal polarization field within the monolayer. While efforts are made to achieve high-quality Janus monolayers, the existing methods rely on highly energetic processes that introduce unwanted grain-boundary and point defects with still unexplored effects on the material's structural and excitonic properties Through high-resolution scanning transmission electron microscopy (HRSTEM), density functional theory (DFT), and optical spectroscopy measurements; this work introduces the most encountered and energetically stable point defects. It establishes their impact on the material's optical properties. HRSTEM studies show that the most energetically stable point defects are single (VS and VSe) and double chalcogen vacancy (VS -VSe), interstitial defects (Mi), and metal impurities (MW) and establish their structural characteristics. DFT further establishes their formation energies and related localized bands within the forbidden band. Cryogenic excitonic studies on h-BN-encapsulated Janus monolayers offer a clear correlation between these structural defects and observed emission features, which closely align with the results of the theory. The overall results introduce the defect genome of Janus TMDs as an essential guideline for assessing their structural quality and device properties.

Identification of Exciton Complexes in Charge-Tunable Janus WSeS Monolayers.

Janus transition-metal dichalcogenide monolayers are artificial materials, where one plane of chalcogen atoms is replaced by chalcogen atoms of a different type. Theory predicts an in-built out-of-plane electric field, giving rise to long-lived, dipolar excitons, while preserving direct-bandgap optical transitions in a uniform potential landscape. Previous Janus studies had broad photoluminescence (>18 meV) spectra obfuscating their specific excitonic origin. Here, we identify the neutral and the negatively charged inter- and intravalley exciton transitions in Janus WSeS monolayers with ∼6 meV optical line widths. We integrate Janus monolayers into vertical heterostructures, allowing doping control. Magneto-optic measurements indicate that monolayer WSeS has a direct bandgap at the K points. Our results pave the way for applications such as nanoscale sensing, which relies on resolving excitonic energy shifts, and the development of Janus-based optoelectronic devices, which requires charge-state control and integration into vertical heterostructures.

Improvements in 2D p-type WSe2 transistors towards ultimate CMOS scaling.

This paper provides comprehensive experimental analysis relating to improvements in the two-dimensional (2D) p-type metal-oxide-semiconductor (PMOS) field effect transistors (FETs) by pure van der Waals (vdW) contacts on few-layer tungsten diselenide (WSe2) with high-k metal gate (HKMG) stacks. Our analysis shows that standard metallization techniques (e.g., e-beam evaporation at moderate pressure ~ 10-5 torr) results in significant Fermi-level pinning, but Schottky barrier heights (SBH) remain small (< 100 meV) when using high work function metals (e.g., Pt or Pd). Temperature-dependent analysis uncovers a more dominant contribution to contact resistance from the channel access region and confirms significant improvement through less damaging metallization techniques (i.e., reduced scattering) combined with strongly scaled HKMG stacks (enhanced carrier density). A clean contact/channel interface is achieved through high-vacuum evaporation and temperature-controlled stepped deposition providing large improvements in contact resistance. Our study reports low contact resistance of 5.7 kΩ-µm, with on-state currents of ~ 97 µA/µm and subthreshold swing of ~ 140 mV/dec in FETs with channel lengths of 400 nm. Furthermore, theoretical analysis using a Landauer transport ballistic model for WSe2 SB-FETs elucidates the prospects of nanoscale 2D PMOS FETs indicating high-performance (excellent on-state current vs subthreshold swing benchmarks) towards the ultimate CMOS scaling limit.

Intralayer charge-transfer moiré excitons in van der Waals superlattices.

Moiré patterns of transition metal dichalcogenide heterobilayers have proved to be an ideal platform on which to host unusual correlated electronic phases, emerging magnetism and correlated exciton physics. Whereas the existence of new moiré excitonic states is established1-4 through optical measurements, the microscopic nature of these states is still poorly understood, often relying on empirically fit models. Here, combining large-scale first-principles GW (where G and W denote the one-particle Green's function and the screened Coulomb interaction, respectively) plus Bethe-Salpeter calculations and micro-reflection spectroscopy, we identify the nature of the exciton resonances in WSe2/WS2 moiré superlattices, discovering a rich set of moiré excitons that cannot be captured by prevailing continuum models. Our calculations show moiré excitons with distinct characters, including modulated Wannier excitons and previously unidentified intralayer charge-transfer excitons. Signatures of these distinct excitonic characters are confirmed experimentally by the unique carrier-density and magnetic-field dependences of different moiré exciton resonances. Our study highlights the highly non-trivial exciton states that can emerge in transition metal dichalcogenide moiré superlattices, and suggests new ways of tuning many-body physics in moiré systems by engineering excited-states with specific spatial characters.

Analysis of Schottky barrier heights and reduced Fermi-level pinning in monolayer CVD-grown MoS2field-effect-transistors.

Chemical vapor deposition (CVD)-grown monolayer (ML) molybdenum disulfide (MoS2) is a promising material for next-generation integrated electronic systems due to its capability of high-throughput synthesis and compatibility with wafer-scale fabrication. Several studies have described the importance of Schottky barriers in analyzing the transport properties and electrical characteristics of MoS2field-effect-transistors (FETs) with metal contacts. However, the analysis is typically limited to single devices constructed from exfoliated flakes and should be verified for large-area fabrication methods. In this paper, CVD-grown ML MoS2was utilized to fabricate large-area (1 cm × 1 cm) FET arrays. Two different types of metal contacts (i.e. Cr/Au and Ti/Au) were used to analyze the temperature-dependent electrical characteristics of ML MoS2FETs and their corresponding Schottky barrier characteristics. Statistical analysis provides new insight about the properties of metal contacts on CVD-grown MoS2compared to exfoliated samples. Reduced Schottky barrier heights (SBH) are obtained compared to exfoliated flakes, attributed to a defect-induced enhancement in metallization of CVD-grown samples. Moreover, the dependence of SBH on metal work function indicates a reduction in Fermi level pinning compared to exfoliated flakes, moving towards the Schottky-Mott limit. Optical characterization reveals higher defect concentrations in CVD-grown samples supporting a defect-induced metallization enhancement effect consistent with the electrical SBH experiments.

Reaching the Excitonic Limit in 2D Janus Monolayers by In Situ Deterministic Growth.

Named after the two-faced Roman god of transitions, transition metal dichalcogenide (TMD) Janus monolayers have two different chalcogen surfaces, inherently breaking the out-of-plane mirror symmetry. The broken mirror symmetry and the resulting potential gradient lead to the emergence of quantum properties such as the Rashba effect and the formation of dipolar excitons. Experimental access to these quantum properties, however, hinges on the ability to produce high-quality 2D Janus monolayers. Here, these results introduce a holistic 2D Janus synthesis technique that allows real-time monitoring of the growth process. This prototype chamber integrates in situ spectroscopy, offering fundamental insights into the structural evolution and growth kinetics, that allow the evaluation and optimization of the quality of Janus monolayers. The versatility of this method is demonstrated by synthesizing and monitoring the conversion of SWSe, SNbSe, and SMoSe Janus monolayers. Deterministic conversion and real-time data collection further aid in conversion of exfoliated TMDs to Janus monolayers and unparalleled exciton linewidth values are reached, compared to the current best standard. The results offer an insight into the process kinetics and aid in the development of new Janus monolayers with high optical quality, which is much needed to access their exotic properties.

Room-Temperature Synthesis of 2D Janus Crystals and their Heterostructures.

Janus crystals represent an exciting class of 2D materials with different atomic species on their upper and lower facets. Theories have predicted that this symmetry breaking induces an electric field and leads to a wealth of novel properties, such as large Rashba spin-orbit coupling and formation of strongly correlated electronic states. Monolayer MoSSe Janus crystals have been synthesized by two methods, via controlled sulfurization of monolayer MoSe2 and via plasma stripping followed thermal annealing of MoS2 . However, the high processing temperatures prevent growth of other Janus materials and their heterostructures. Here, a room-temperature technique for the synthesis of a variety of Janus monolayers with high structural and optical quality is reported. This process involves low-energy reactive radical precursors, which enables selective removal and replacement of the uppermost chalcogen layer, thus transforming classical transition metal dichalcogenides into a Janus structure. The resulting materials show clear mixed character for their excitonic transitions, and more importantly, the presented room-temperature method enables the demonstration of first vertical and lateral heterojunctions of 2D Janus TMDs. The results present significant and pioneering advances in the synthesis of new classes of 2D materials, and pave the way for the creation of heterostructures from 2D Janus layers.

Anomalous Behavior of 2D Janus Excitonic Layers under Extreme Pressures.

Newly discovered 2D Janus transition metal dichalcogenides layers have gained much attention from a theory perspective owing to their unique atomic structure and exotic materials properties, but little to no experimental data are available on these materials. Here, experimental and theoretical studies establish the vibrational and optical behavior of 2D Janus S-W-Se and S-Mo-Se monolayers under high pressures for the first time. Chemical vapor deposition (CVD)-grown classical transition metal dichalcogenides (TMD) monolayers are first transferred onto van der Waals (vdW) mica substrates and converted to 2D Janus sheets by surface plasma technique, and then integrated into a 500 µm size diamond anvil cell for high-pressure studies. The results show that 2D Janus layers do not undergo phase transition up to 15 GPa, and in this pressure regime, their vibrational modes exhibit a nonmonotonic response to the applied pressures (dω/dP). Interestingly, these 2D Janus monolayers exhibit unique blueshift in photoluminescence (PL) upon compression, which is in contrast to many other traditional semiconductor materials. Overall theoretical simulations offer in-depth insights and reveal that the overall optical response is a result of competition between the ab-plane (blueshift) and c-axis (redshift) compression. The overall findings shed the very first light on how 2D Janus monolayers respond under extreme pressures and expand the fundamental understanding of these materials.

The effect of tranexamic acid in blood loss and transfusion volume in adolescent idiopathic scoliosis surgery: a single-surgeon experience.

PURPOSE: Intraoperative blood loss in scoliosis surgery often requires transfusions. Autogenous blood decreases but does not eliminate risks typically associated with allogenic blood transfusion. Costs associated with transfusions are significant. Tranexamic acid (TXA) has been shown to decrease blood loss in cardiac and joint surgery. Few studies have examined its use in pediatric spine surgery, and the results are inconsistent. The aim of this study was to determine whether TXA decreases intraoperative blood loss and transfusion requirements in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion by a single surgeon. METHODS: The medical records and operative reports of surgically treated patients with adolescent idiopathic scoliosis between 2000 and 2009 were retrospectively reviewed. The inclusion criteria were: (1) patients who underwent instrumented posterior spinal fusion, (2) had complete medical records, and (3) were treated by the same surgeon. Forty-nine patients who met the inclusion criteria were divided into two groups: Group A (25 patients) received TXA, while Group B (24 patients) did not receive TXA. RESULTS: After controlling for age at the time of surgery, gender, and number of vertebral levels fused, the mean intraoperative blood loss was significantly lower in Group A (537 ml) than in Group B (1,245 ml) (p = 0.027). The mean volume of blood transfused intraoperatively was 426 and 740 ml for Group A and Group B, respectively. The difference was not statistically significant after controlling for age, gender, and number of levels fused (p = 0.078). CONCLUSION: TXA significantly decreased intraoperative blood loss in posterior spinal fusions performed for adolescent idiopathic scoliosis.

Taylor spatial frame in the treatment of upper extremity conditions.

BACKGROUND: Taylor spatial frame (TSF) is a modern multiplanar external fixator that combines ease of application and computer accuracy; it provides the capability of 1 to 6 axes of deformity correction sequentially or simultaneously by adjusting 6 connecting struts between 2 circular rings. Previous reports have documented the effectiveness of the TSF in acute fracture care, nonunion treatment, and in bone lengthening and deformity correction in the lower extremity. To the authors' knowledge, no previous case series in the English literature have documented the use of the TSF in treating upper extremity conditions. Our experience with the use of this external fixator in the treatment of upper extremity length abnormality, angulation, and bone transport is summarized. METHODS: Over a period of 7 years, TSF was used in 12 patients with varying upper extremity pathologies that were collected from our prospective external fixator database. The classic TSF planning strategy was adopted and the TSF web-based program was used. All cases were followed for a minimum of 2 years. The database and radiographs were reviewed to obtain demographic data, malalignment parameters, final correction, time in the TSF, and complications. RESULT: Patients' ages ranged from 8 to 18 years. Eight humeral and 4 radial cases were identified. These included 4 cubitus varus and 1 cubitus valgus deformity, 1 neglected supracondylar fracture, 2 humeral nonunion, 2 radial malunion cases, and 1 radial shaft septic nonunion. Time in the TSF varied according to patient age and bone involved. Five patients had superficial pin site infections that resolved with oral antibiotics. Postoperatively mean final angulation on the anteroposterior radiograph was 1 degree (range, 0 to 5 degrees) and the mean final angulation on the lateral radiograph was 0.5 degrees (range, 0 to 2 degrees). Union of bone was achieved in all cases. CONCLUSIONS: The TSF is an external fixator that can be successfully used as a treatment alternative for the definitive treatment of upper extremity conditions involving a deformity and or shortening or bone transport in the pediatric and adolescent patient population. LEVEL OF EVIDENCE: Level IV.

Lower limb lengthening and deformity correction using the Fitbone motorized nail system in the adolescent patient.

Leg lengthening by an external fixation is associated with various difficulties. Pin-tract infections are commonly encountered, and muscle contractures and joint stiffness are additional complications associated with this method. Several researchers explored a purely intramedullary solution for leg lengthening since the 1970s. The purpose of this study was to evaluate the results of 10 adolescent patients who underwent leg lengthening with a motorized intramedullary lengthening device (the Fitbone System). We aimed to evaluate the effectiveness of the Fitbone system in deformity correction and lengthening of the femur and tibia in the pediatric and adolescent patients looking at whether the incidence of complications commonly associated with external fixators could be reduced. We compared our preliminary results with those from other reports, with a focus on leg length achieved and rate of complications. Ten patients were included, nine femoral nails and five tibial nails were implanted. The average lengthening distance was 4.8 cm (range, 2.8-10 cm). In 10 patients, leg lengthening was combined with successful correction of the mechanical axis alignment in three patients. The consolidation index averaged 24 days/cm (range, 20-39 days/cm). The average hospital stay was 8 days. No bone or soft tissue infections were observed. Only one patient had irritation and pain from the antenna system after lengthening and recovered fully after antenna removal. Our results suggest that the difficulties commonly associated with external fixators can be reduced with this method. It also allows good angular correction in patients with mechanical axis deviation. These features combined with a short time of hospitalization make it a promising procedure for limb lengthening in adolescent patients.

Tuberculous arthritis revisited as a forgotten cause of monoarticular arthritis.

BACKGROUND AND OBJECTIVES: Tuberculosis (TB) continues to be a major concern for health care workers. The number of reported cases of extrapulmonary tuberculosis, particularly osteoarticular tuberculosis, is increasing. This fact is attributed to different factors such as underestimating the disease and difficulty in diagnosis, which requires tissue sampling and can lead to a delay in the diagnosis, and can result in significant morbidity and mortality. The aim of this study was to highlight the difficulties and delay in diagnosis of articular tuberculosis, raising the need to create awareness about the importance of early diagnosis to avoid major complications of joint destruction. DESIGN AND SETTING: Retrospective review of patients presenting to a tertiary care center between 2003 and 2009. PATIENTS AND METHODS: We reviewed cases who presented with monoarticular joint pain and swelling that failed to respond to treatment elsewhere and were eventually diagnosed as having articular tuberculosis. We collected the demographic data, history, data on clinical examination and the relevant laboratory investigations, in addition to the data on radiological studies. All patients were treated medically with antituberculosis chemotherapy and surgically according to the severity of joint destruction. RESULTS: Thirteen patients had a mean age was 40 years (range, 17-70 years). The average delay in diagnosis was 2 years. Only 1 patient had pulmonary TB. The hip, knee and elbow were the most common joints involved. Bacteriology was positive in 69% of the cases; and histopathology, in 92%. Fifteen percent of the patients had arthrodesis. None showed recurrence after follow-up of 4 years. CONCLUSION: A high level of clinical suspicion is essential for early diagnosis and treatment of osteoarticular TB to reduce its significant morbidity.

Evaluation of the calori et Al nonunion scoring system in a retrospective case series.

Nonunion is one of the most challenging orthopedic complications. Although current definitions are accepted, they fail to provide a satisfactory definition of nonunion. Different classifications for nonunion have been described, but these systems did not take all required factors and requirements of nonunion treatment into account for fracture healing. Calori et al recently developed a new comprehensive nonunion scoring system, which takes into account the whole fracture personality that influences non-union. The aim of this study is to evaluate the validity of the Calori et al system in the treatment of nonunions. We retrospectively reviewed our database for lower extremity nonunion from 2002 to 2009. The demographic and clinical data, laboratory, and radiological investigations were collected from medical records and phone interviews. Forty cases were identified: 32 men and 8 women. Mean patient age was 39.75 years (range, 6-102 years). Seventeen were femoral and 23 were tibial. Our patients were divided into 3 groups according to the database treatment: group 1 standard treatment (3 patients), group 2 specialized care and treatment (33 patients), group 3 amputations (4 patients). If we apply the recommended management by Calori et al to our patients, they will be divided into groups similar to the database treatments. Statistical analysis showed significant correlation between our actual treatment and those recommended by the Calori system where the P value was <.01. We concluded that the Calori et al scoring system could be valid as a guideline for lower extremity nonunion treatment.

Taylor spatial frame in the treatment of neglected fractures.

BACKGROUND: The Taylor spatial frame (TSF, Smith and Nephew, Memphis, TN, USA) is a modern multiplanar external fixator that combines ease of application and computer accuracy. Many patients in our geographic area seek treatment for their fractures by traditional bonesetters and present in the middle of treatment with neglected malaligned fractures. These fractures were an average of 10 weeks old (range 6-14 weeks) fractures with callus that were allowed to heal in a poor position. The spatial frame is applied easily on the fracture bone fragments. The accuracy of fracture reduction and deformity correction is dependant on analyzing anteroposterior and lateral radiographs of the fracture. Our experience with this external fixator in the treatment of neglected fractures is summarized. METHOD: Over a period of 6 years, the TSF was used in 24 neglected fracture cases which were collected from our prospective external fixator data base. All cases were followed for a minimum of 3 years. The data base and radiographs were reviewed in order to obtain demographic data, malalignment parameters, final correction, time in the TSF, and complications. RESULT: The patients' ages ranged from 6 to 18 years. All were neglected fractures. The average delay in treatment was 10 weeks (range 6-14 weeks). All patients had closed osteoclasis. The time spent in the TSF varied according to the patient age and bone involved. Ten femoral and 14 tibial fractures were included. Ten patients had superficial pin site infections that resolved with oral antibiotics. Postoperatively, no patient was noted to be more than 5° malrotated on clinical examination and no functional leg length discrepancy was observed. All of the fractures united. CONCLUSION: Anatomic alignment was achieved in all tibial fracture patients. At the final follow-up, fracture angulation and shortening were fully corrected, and some translational malalignment persisted in 67% of femur fractures. The TSF is an effective definitive method for the treatment of neglected fractures. LEVEL OF EVIDENCE: IV.

Results of primary total hip replacement with special attention to technical difficulties encountered in a cohort of Saudi patients.

OBJECTIVE: To illustrate our experience and the difficulty faced in primary total hip replacement (THR) in Saudi patient population. METHODS: We retrospectively reviewed our database between February 2002 to December 2007 for primary THR cases at King Abdul-Aziz University Hospital, Jeddah, Saudi Arabia and identified 58 hips (54 patients). Patients data were collected from patient's medical records, clinical examination, and x-ray films. Operative reports were examined for the difficulty encountered during surgery and was classified into femoral, acetabular, soft tissue and combined difficulties. Patients follow up was a minimum of 2 years. RESULTS: The indication of surgery was posttraumatic arthritis in 50%, sickle cell anemia related avascular necrosis in 16.6%, primary osteoarthritis in 9.2%, idiopathic avascular necrosis in 9.2%, rheumatoid arthritis in 7.4%, and other indications were 14.7%. The femoral obstacles included narrow femoral canal in 27.7% and proximally migrated femur in 5.5%. Acetabular obstacles included protrusio acetabuli in 14.8% and structural posterior acetabular bone defect in 5.5%. Soft tissue obstacles included tight capsule in 14.8% and muscle contracture in 11.1%. CONCLUSION: Our Saudi patient population has shown different pathology of their hip disease in which most of the hips being posttraumatic as compared to series published in the west. We advised those who intend to tackle THR in this population to perform extensive preoperative planning in order to be able to anticipate the difficulty demonstrated by our experience.

Taylor spatial frame in the treatment of open tibial shaft fractures.

BACKGROUND: The Taylor spatial frame (TSF) is a modern multiplanar external fixator that combines the ease of application and computer accuracy in the reduction of fractures. A retrospective review of our prospective TSF database for the use of this device for treating open tibial fractures in pediatric, adolescent, and adult patients was carried out to determine the effectiveness and complications of TSF in the treatment of these fractures. MATERIALS AND METHODS: Nineteen male patients with open tibial fractures were included. Of these fractures, 10 were Gustilo Type II, five were Gustilo Type IIIA (two had delayed primary closure and three had split thickness skin grafting), and four were Gustilo Type IIIB (all had rotational flaps). Twelve of our patients presented immediately to the emergency room, and the remaining seven cases presented at a mean of 3 months (range, 2.2-4.5 months) after the initial injury. The fractures were located in proximal third (n=1), proximal/middle junction (n=2), middle third (n=3), middle/distal junction (n=8), distal third (n=3), and segmental fractures (n=2). Patients were of an average age of 26 years (range, 6-45years). Mean duration of follow-up was 3.5 years. RESULTS: All fractures healed over a mean of 25 weeks (range, 9-46 weeks). All were able to participate in the activities of daily living without any difficulty and most were involved in sports during the last follow-up. Postoperative complications included pin tract infection in 12 patients. CONCLUSION: The TSF is an effective definitive method of open tibial fracture care with the advantage of early mobilization, ease of soft tissue management through gradual fracture reduction, and the ability to postoperatively manipulate the fracture into excellent alignment.

Ultrastructural changes of compressed lumbar ventral nerve roots following decompression.

OBJECTIVE: To study whether there will be a permanent lumbar nerve root scarring or degeneration secondary to continuous compression followed by decompression on the nerve roots, which can account for postlaminectomy leg weakness or back pain. METHODS: The study was performed at the Department of Anatomy, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia during 2003-2005. Twenty-six adult male New Zealand rabbits were used in the present study. The ventral roots of the left fourth lumbar nerve were clamped for 2 weeks then decompression was allowed by removal of the clips. The left ventral roots of the fourth lumbar nerve were excised for electron microscopic study. RESULTS: One week after nerve root decompression, the ventral root peripheral to the site of compression showed signs of Wallerian degeneration together with signs of regeneration. Schwann cells and myelinated nerve fibers showed severe degenerative changes. Two weeks after decompression, the endoneurium of the ventral root showed extensive edema with an increase in the regenerating myelinated and unmyelinated nerve fibers, and fibroblasts proliferation. Three weeks after decompression, the endoneurium showed an increase in the regenerating myelinated and unmyelinated nerve fibers with diminution of the endoneurial edema, and number of macrophages and an increase in collagen fibrils. Five and 6 weeks after decompression, the endoneurium showed marked diminution of the edema, macrophages, mast cells and fibroblasts. The endoneurium was filled of myelinated and unmyelinated nerve fibers and collagen fibrils. CONCLUSION: Decompression of the compressed roots of a spinal nerve is followed by regeneration of the nerve fibers and nerve recovery without endoneurial scarring.

Taylor Spatial Frame in the treatment of pediatric and adolescent tibial shaft fractures.

The Taylor Spatial Frame (TSF) is a modern multiplanar external fixator that combines ease of application plus computer accuracy in the reduction of fractures. A retrospective review of our experience in using this device for treating unstable tibia fractures in pediatric and adolescent patients was carried out to determine the effectiveness and complications of TSF in the treatment of these fractures. Ten tibia fractures were included. All patients were boys with an average age of 12 years (range 8-15 years). Mean duration of follow-up was 3.1 years. These fractures included 5 open fractures. All fractures healed over a mean of 18 weeks. All patients were doing well and involved in sports when last seen. Postoperative complications included pin tract infection in 5 patients. TSF is an effective definitive method of tibia fracture care with the advantage of early mobilization and ability to postoperatively manipulate fracture into excellent alignment.

Video-assisted thoracoscopic surgery: the Cincinnati experience.

Video-assisted thoracoscopic surgery is an alternative to open thoracotomy. We analyzed our experience during a consecutive series of 100 patients who had this procedure and who were available for study at 3-year followup. Video-assisted thoracoscopic surgery was done on patients with the following diagnoses: idiopathic scoliosis (n = 49), neuromuscular spinal deformity (n = 15), Scheuermann kyphosis (n = 15), congenital and infantile scoliosis (n = 5), neurofibromatosis (n = 5), Marfan (n = 1), postradiation scoliosis (n = 1), and repair of pseudoarthrosis (n = 1). Four patients had excision of the first rib to treat thoracic outlet syndrome. One patient had excision of an intrathoracic neurofibroma and one a benign rib tumor. One had anterior arthrodesis after fracture-dislocation of the thoracic spine and another had anterior fusion for vertebral osteomyelitis. The average operative time for the thoracoscopic anterior release with discectomy and arthrodesis was 253 minutes. The average number of discs excised was 8. Final postoperative scoliosis and kyphosis corrections were 68% and 90%, respectively. Complications related to thoracoscopy occurred in eight patients. Video-assisted thoracoscopic surgery provides a safe and effective alternative to open thoracotomy in the treatment of thoracic pediatric spinal deformities.