Proper Screw Research Articles

Creep behavior of Biodegradable Triple-component Nanocomposites Based on PLA/PCL/bioactive Glass for ACL Interference Screws.

Short-time creep behaviorfor aseries of biodegradable nanocomposites, which areused as implantable devices inthe body, is a crucial factor.The present study aimed to investigate the effect of bioactive glass nanoparticles (BGn) on creep and creep-recovery behaviors of polylactic acid/polycaprolactone (PLA/PCL) blends at different given loads and different applied temperatures. A series of biodegradable nanocomposites consisted of PLA/PCL blends (comprising 80 parts PLA and 20 parts PCL) with different amounts of modified-BGn (m-BGn) fillers were prepared using the evaporated solvent casting technique. Creep and creep-recovery behaviors of all specimens were studied at different valuable stressesof 3 and 6 MPa and different given temperatures of 25 and 37°C. In all cases, m-BGn improved the creep resistance of the nanocomposites due to the retardation effect during the creep behaviors of the nanocomposite systems. The obtained results in terms of creep and creep-recovery properties determined that the nanocomposites of PLA/PCL/m-BGn can satisfy the required conditions of an appropriate anterior cruciate ligament reconstruction (ACL-R) screw. The obtained results confirmed that the BGn plays an impeding role in the movement of PLA/PCL chains leading to in increase the creep resistance. According to the results, it was determined that the nanocomposites of PLA/PCL and m-BGn can satisfy the required circumstances of a proper ACL-R screw.

An Anatomic Approach for Intramedullary Screw Fixation of Fifth Metatarsal Fracture: A Clinical and Radiographic Study

Category:Ankle, Sports, TraumaIntroduction/Purpose:Intramedullary screw fixation is the most common surgical intervention for treating Jones fractures and diaphyseal stress fractures of the fifth metatarsal. Proper screw placement is paramount to surgical success. There have been studies describing more traditional antegrade and retrograde approaches, dependent upon fluoroscopy and guidewires. However, we propose a novel, more efficient surgical approach that utilizes anatomical landmarks and plantarflexion angle during screw fixation. The purpose of this study was to evaluate screw position and radiographic healing parameters, return to sport, and patient-reported outcome measures after utilization of our technique for screw fixation of the fifth metatarsal fracture.Methods:This is a retrospective review from 2007 to 2017 of clinical records and radiographs of 31 consecutive patients who had fifth metatarsal fracture open reduction internal fixation using anatomical landmarks and plantarflexion angle (Johnson, Labib and Fowler 2004). The classification of the fracture, surgery time, time to union, and post-operative complications were collected. Return to sport, Tegner score, the Foot and Angle Disability Index (FADI) Sports Module, and the Short Form 12 Physical and Mental Health Composite Scale (SF-PCS/MCS) were obtained through phone interview. Post-operative X-ray analysis, including screw position and bone healing percentage, were evaluated. Post-operative screw position was described as either center-center, oblique, or cortical breach on anteroposterior, lateral or oblique view. Fisher’s exact test was used to determine the difference among frequencies of each screw position. P<0.05 was considered significant.Results:Patient and surgical information were shown in Table 1. Average post-operative follow-up was 98 (36-227) days. Screws were well center-center positioned at all three views on post-op X-ray in most cases (all p<0.001). No case showed the screw protruding into tarsometatarsal joint or cuboid impingement. Average phone interview follow-up was 5.4 (1.0-11.1) years. Tegner scores showed no difference (p=0.58) when compared between pre-injury (6.4) and current level (6.1). At the terminal follow-up, average FADI-sports was 87.2 (37.5-100), SF-PCS was 50.7 (27.3-55.6), and SF-MCS was 59.7 (52.9-67.2). In addition, 12 of 15 (80%) the college or professional athletes (1 lost to follow-up) returned to the same level sports after the surgery.Conclusion:This study quantified the benefit of a novel technique for intramedullary screw fixation of fifth metatarsal fracture that was reliable and reproducible. It facilitated accurate screw positioning, dependable union, and accompanying positive return to sport and patient-reported outcome measures.

Determination of S1 screw adjustment parameters using by 3D CT images in healthy subjects

Background: The aim of this study was to investigate the anthropometry of the posterior superior iliac spine (PSIS) types in the Turkish population and to determine the safe limits of the length and angle of the sacrum by the posterior lumber approach in lumbosacral instrumentation surgery. Material and Method: Sacral regions (left and right pedicle lengths and pedicle angles) and PSIS types of healthy subjects were evaluated using 3D images. Results: A total of 111 patients (58 males and 53 females) were included in the study. The mean age was 46.9 ± 14.8 in males and 44.3 ± 16.4 in females. In men, the right pedicle length was 52.83 mm, the left pedicle length was 53.81 mm, the right pedicle angle was 35.84, the left pedicle angle was 35.13, and the caudal angle was 39.24 degrees. In females, right pedicle length was 48.88 mm, left pedicle length was 49.28 mm, right and left pedicle angle was 35.83, and caudal angle was 39.24 degrees. PSIS type 1 was found to be 58.6%, type 2 32.4% and type 3 9%. Conclusion: Optimal screw lengths, angles and proper screw orientations can be easily and safely operated in posterior stabilization. In this study, morphometric and anthropometric information related to sacral screw orientation were also determined. These data may help to prevent surgical complications by contributing to the surgeon about preoperative anatomical structure in lumbosacral surgery stabilization procedures.

Robotic-assisted navigated minimally invasive pedicle screw placement in the first 100 cases at a single institution

Proper pedicle screw placement is an integral part of spine fusion requiring expertly trained spine surgeons. Advances in medical imaging guidance have improved accuracy. There is high interest in the emerging field of robot-assisted spine surgery; however, safety and accuracy studies are needed. This study describes the pedicle screw placement of the first 100 cases in which navigated robotic assistance was used in a private practice clinical setting. A single-surgeon, single-site retrospective Institutional Review Board-exempt review of the first 100 navigated robot-assisted spine surgery cases was performed. An orthopaedic surgeon evaluated screw placement using plain film radiographs. In addition, pedicle screw malposition, reposition, and return to operating room (OR) rates were collected. Results demonstrated a high level (99%) of successful surgeon assessed pedicle screw placement in minimally invasive navigated robot-assisted spine surgery, with no malpositions requiring return to the OR.

Difference in magnetic and ferroelectric properties between rhombohedral and hexagonal polytypes of AgFeO2 : A single-crystal study

We have investigated magnetic and dielectric properties of rhombohedral $3R\ensuremath{-}{\mathrm{AgFeO}}_{2}$ and hexagonal $2\mathrm{H}\ensuremath{-}{\mathrm{AgFeO}}_{2}$ by using magnetic and dielectric bulk measurements and a neutron diffraction experiment with single crystals grown by hydrothermal synthesis. Magnetic phase transitions occur at $T=14.0$ K and $T=6.0$ K in $3R\ensuremath{-}{\mathrm{AgFeO}}_{2}$ and $T=17.0$ K and $T=9.5$ K in $2H\ensuremath{-}{\mathrm{AgFeO}}_{2}$ under zero magnetic field. Multistep metamagnetic phase transitions were observed in $3R\ensuremath{-}{\mathrm{AgFeO}}_{2}$ in magnetization measurements up to 60 T, while a single phase transition occurs in $2H\ensuremath{-}{\mathrm{AgFeO}}_{2}$. The ferroelectric polarization parallel and perpendicular to the triangular lattice plane appears below $T=6.0\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ in $3R\ensuremath{-}{\mathrm{AgFeO}}_{2}$, which is concomitant with the onset of the cycloid magnetic ordering with the propagation vector $\mathbit{k}=(\ensuremath{-}\frac{1}{2},q,\frac{1}{2};q\ensuremath{\simeq}0.2)$ and the magnetic point group polar $m{1}^{\ensuremath{'}}$. On the other hand, the ferroelectric polarization is absent even below the lower phase transition temperature in $2H\ensuremath{-}{\mathrm{AgFeO}}_{2}$, which can be explained by the proper screw magnetic structure with $\mathbit{k}=(0,q,0;q\ensuremath{\simeq}0.4)$ and the nonpolar ${2221}^{\ensuremath{'}}$ point group. Although the two-dimensional triangular lattice layers of ${\mathrm{Fe}}^{3+}$ are common in the two polytypes, the magnetic and ferroelectric properties are significantly different. The emergence of ferroelectric polarization which is not confined to be within the plane of the cycloid for $3R\ensuremath{-}{\mathrm{AgFeO}}_{2}$ can be explained by the extended inverse Dzyaloshinskii-Moriya effect with two orthogonal components, ${\mathbit{p}}_{1}\ensuremath{\propto}{\mathbit{r}}_{ij}\ifmmode\times\else\texttimes\fi{}[{\mathbit{S}}_{i}\ifmmode\times\else\texttimes\fi{}{\mathbit{S}}_{j}]$ and ${\mathbit{p}}_{2}\ensuremath{\propto}{\mathbit{S}}_{i}\ifmmode\times\else\texttimes\fi{}{\mathbit{S}}_{j}$. Unlike other delafossite compounds, the ${\mathbit{p}}_{2}$ component is not allowed in the proper screw phase of $2H\ensuremath{-}{\mathrm{AgFeO}}_{2}$ due to the symmetry restriction of the parent space group.

Disruption of lignocellulosic biomass along the length of the screws with different screw elements in a twin-screw extruder

Proper screw design is crucial for effectively pre-treating wood fibers, to assist in the downstream enzymatic conversion of the cellulose into fermentable sugars. Initially, the impact of extruder barrel temperature (50, 100, and 150 °C) and screw speed (25, 50, and 75 rpm) were studied to arrive at the optimum conditions for sugar yield. Lower temperatures and screw speeds resulted in increased sugar yields. To examine the influence of shear imparted by the screws, the residuals samples were recovered from different zones along the screws and evaluated. Sugar yield, crystallinity index, and the particle size distribution of the material collected at different zones were determined. Glucose yield and xylose/mannose yields of the material along the screws, ranged from 23.25 to 42.88% and from 11.95 to 20.54%, respectively. The importance of the screw design was highlighted.

Posterior L5-S1 transdiscal screws for high grade spondylolisthesis - a systematic review.

The surgical management of high-grade lumbar spondylolisthesis (HGLS) is complex and aims to achieve both a solid fusion that is able to support the high shear forces of the lumbosacral junction, as well as neural decompression. We performed a systematic literature review of the safety and efficacy of posterior transdiscal (PTD) screw fixation from L5S1 for HGLS and its variations. A systematic literature review following the PRISMA guidelines was performed in the PubMed database of the studies describing the use of PTD screw fixation for HGLS. Clinical and radiological data were extracted and discussed. Study quality was assessed with the Oxford Centre for Evidence-Based Medicine Levels of Evidence. Seven studies were included and reviewed; all of them were level IV of evidence. Two of them had large case series comparing different surgical techniques: one concluded that PTD was associated with better clinical outcomes when compared with standard screw fixation techniques and the other suggesting that the clinical and radiological outcomes of PTD were similar to those when an interbody fusion (TLIF) technique was performed, but PTD was technically less challenging. The remaining five studies included small case series and case reports. All of them reported the successful useful of PTD with or without technical variations. Our review concludes, with limited level of evidence that PTD fixation is a safe and efficient technique for treating HGLS patients. It is technically less demanding than a circumferential fusion, even though proper screw insertion is more demanding than conventional pedicle screw fixation.

Jones Fractures—Plating and IM Screws: Technique of ORIF Jones Fractures, Reduction, Deciding Proper Screw Size, and Plating Options

It has been over 110 years since the Jones fracture was originally described, and in the modern era the clinical management of this entity continues to improve. With respect to the anatomy, the vascular implications driving union abnormalities are well understood. However, optimizing the clinical outcome depends on identifying the correct orthopedic intervention. Intramedullary fixation has proven to be a reliable repair method, with both strong clinical outcomes and a relatively simple operative method. Though, when considering the elite athlete, there is a well-documented complication rate. Plating has been useful in cases of severe communition, however the lateral hook plate has been shown to be biomechanically inferior compared to the intramedullary screw. In our study we will investigate the history of the Jones fracture, and analyze the methodology that drives the modern day operative algorithm. Furthermore, we will discuss the indications and techniques for plating and intramedullary fixation.

P190 - In Vitro Analysis of Accuracy, Dosage and Surgical Time Required for Pedicle Screw Placement Using Conventional Percutaneous Screw and Robotic-Assisted Screw Techniques

BACKGROUND CONTEXT: Surgery is evolving from open to MIS techniques. Anatomic anomalies, or other patient factors such as deformity or degeneration, may affect pedicle screw accuracy, particularly in the two-dimensional visualization system of fluoroscopic-based MIS. Proper screw placement is associated with improved fixation, which has led to use of free hand navigation, and subsequently, robot guidance systems. Presently, robotic systems which differ in their mechanical set-up, have not been adequately compared to traditional MIS techniques.

A new intraoperative classification of distal tibiofibular syndesmosis injury and internal fixation

Objective To investigate the guidance of a new intraoperative classification of distal tibiofibular syndesmosis injury in the selection of internal fixation for ankle fractures. Methods Between January 2010 and January 2015 our department treated 116 patients with displaced closed ankle fracture (Weber type B or C). They were 60 men and 56 women, aged from 18 to 78 years (average, 45.6 years). After reduction and fixation of the fibular fracture, we assessed the syndesmosis stability using the fibular hook traction test and radiological findings. We classified the distal tibiofibular syndesmosis injury into 3 grades (grade Ⅰ: 7 mm displacement). Se-lection of proper screwing was determined by our new classification. Results Of the 116 cases, 82 (70.7%) demonstrated distal tibiofibular syndesmosis injury. Screwing of the distal tibiofibular syndesmosis was not conducted for 30 (25.9%) of them who were of stable grade Ⅰ. 52 (44.8%) cases were of unstable grades Ⅱ and Ⅲ. Of the 48 cases of grade Ⅱ, 44 were fixated with one screw and the rest 4 became stable grade Ⅰ after Volkmann block fixation and received no screwing. Fixation of the distal tibiofibular syndesmosis with 2 screws was conducted for the 4 cases of unstable grade Ⅲ. All the patients were followed up for 12 to 60 months. No non-union, screw breakage, or syndesmosis separation after screw removal occurred. The American Orthopaedic Foot and Ankle Society ankle-hindfoot scoring showed a good/excellent rate of 93.1% (108/116) . Conclusion Our new intraoperative classification can provide correct judgment of the severity of distal tibiofibular syndesmosis injury, thus guiding the selection of proper screw fixation to enhance the outcomes of ankle fractures. Key words: Ankle joint; Fractures, bone; Fracture fixation, internal; Distal tibiofibular syndesmosis; Classification

Arthroscopic Latarjet Procedure With Anterior Capsular Reconstruction: Clinical Outcome and Radiologic Evaluation With a Minimum 2-Year Follow-Up

To investigate the clinical and radiographic outcomes of the modified arthroscopic Latarjet procedure at a minimum of 2years after surgery. Patients who had traumatic unidirectional anterior shoulder instability and treated with a modified arthroscopic Latarjet procedure were included. During surgery, the anterior capsule was preserved and repaired back to the glenoid after the coracoid transfer. The clinical results (range of motion, American Shoulder and Elbow Surgeons [ASES] score, Constant-Murley score, and Rowe score) and computed tomographic results were followed. From February 2013 to September 2014, 52 consecutive patients were included. The average duration of follow-up was 28.4months (range, 24.0-41.7months). At final follow-up, no recurrent dislocation had occurred. The ASES score and Rowe score improved significantly (ASES score from 85.6 ± 12.7 before surgery to 93.6 ± 5.4 after surgery, P < .0001; Rowe score from 41.5 ± 7.2 before surgery to 92.2 ± 8.7 after surgery, P < .0001). No significant change was found regarding range of motion and the Constant-Murley score. Bone union was achieved in all cases. The transferred coracoid was at the level of the glenoid in all cases. The transferred coracoid was placed below the equator in 48 of 52 cases (92.3%). The orientation of the screw was 22.6° ± 10.8°. Bone resorption around the proximal screw was significantly more prominent than that around the distal screw (P < .0001). The arthroscopic Latarjet procedure with concomitant anterior capsular reconstruction can achieve satisfactory clinical outcomes for the treatment of anterior shoulder instability with marked glenoid bone loss at a minimum of 2years' follow-up. A satisfactory coracoid graft position, proper screw orientation, and high healing rate of the transferred coracoid can be expected. Bone resorption around the proximal screw is more severe than that around the distal screw. Level IV, therapeutic case series.

Magnetic properties and magnetodielectric effect in Y-type hexaferrite Ba0.5Sr1.5Zn2-xMgxFe11AlO22

The effect of Mg substitution on structural, magnetic, and dielectric properties of Y-type hexaferrite Ba0.5Sr1.5Zn2-xMgxFe11AlO22 (x = 0, 0.4, 0.8, 1.2, 1.6, 2.0) prepared by the solid state reaction method was investigated. The X-ray diffraction patterns are analyzed by Rietveld refinement method and the hexagonal structure with R3−m was confirmed. The magnetic transition temperatures associated with the longitudinal conical to proper screw phase transition (T1) and proper screw to ferrimagnetic phase transition (T2) can be modulated by varying Mg content. For x ≤ 1.2 samples, the transition temperature T2 monotonically increases with increasing Mg substitution, suggesting the possibility that the helical spin order of Mg substituted Y-type hexaferrites is sustained up to higher temperatures than that of undoped samples. The saturation magnetization at room temperature increases to a maximum with Mg content x = 1.2 and then decreases with x. The variations of magnetic properties can be attributed to the difference in the preferential site for Zn and Mg and different distribution of Fe3+ ions over tetrahedral and octahedral sites. The results of magnetic field dependence of dielectric constant, i.e., magnetodielectric effect, at various temperatures imply that the doped samples show magnetically induced ferroelectricity up to 250 K. The intrinsic magnetodielectric effect is observed in all the samples. It is worthy to note that the magnetodielectric effect measured below 200 K increases with increasing Mg content, which is probably attributed to the variation of magnetic structures. The Mg-doped hexaferrites Ba0.5Sr1.5Zn2-xMgxFe11AlO22 may be potential candidates for application in magnetoelectric devices.

Is It "In" or "Out"? The Optimal Fluoroscopic Views for Intraoperative Determination of Proper Lateral Mass Screw Placement.

Cadaveric. Determine optimal fluoroscopic views for detecting cervical lateral mass screw (LMS) violations. Single plane intraoperative x-rays are commonly used but frequently inadequate due to its complex trajectory. Fluoroscopy can be taken in multiple planes, but the ideal fluoroscopic view to assess malposition is not known: depending on the view, any given screw may look "in" or "out." C3-6 LMS were inserted in three cadavers. To evaluate neuroforaminal violation, LMS were inserted into the foramen with the tip penetrating the anterior cortex by 0, 2, and 4 mm. To assess facet joint violation, LMS were inserted toward the subjacent facet joint with the tip penetrating the anterior cortex by 0 and 2 mm. Fluoroscopic views were taken 0°, 10°, 20°, 30°, and 40° to the lateral plane. Views were independently evaluated by three blinded spine surgeons. Twenty-degree oblique view correctly identified a 2 mm penetration into the neuroforamen in 79%, and a 4 mm penetration in 86%, for a sensitivity of 83% and specificity of 90%. Thirty-degree view had lower sensitivity (76%) but slightly higher specificity (93%). Twenty-degree and 30° views were significantly more sensitive than the other views. Zero-degree view correctly identified a 2 mm penetration into the facet joint in 93%, for a sensitivity of 93% and specificity of 92%. Ten-degree view had lower sensitivity (72%) but higher specificity (100%). The 0° view was significantly more sensitive than the other views. Twenty-degree and 30° oblique views significantly provided the most sensitive assessment of LMS potentially violating the neuroforamen, whereas the 0° neutral lateral view significantly provided the most sensitive assessment of facet violations. The specificities were also high (in the 90% range) for these views. We recommend the use of these views intraoperatively when assessing proper placement of LMS fluoroscopically. N/A.

C2 and Greater Occipital Nerve: The Anatomic and Functional Implications in Spinal Surgery.

IntroductionPosterior C1-C2 fusion is a highly successful treatment for atlantoaxial instability and other pathologies of the cervical spine, with fusion rates approaching 95%-100%. However, poor visualization of the lateral masses of C1 secondary to the course of the C2 nerve root along with blood loss from the venous plexus and compression of the C2 nerve from lateral mass screws are technical obstacles that can arise during surgery. Thus, sacrifice of the C2 nerve root has long since been debated in fusions involving the C1 and C2 vertebral bodies. MethodsCadaveric dissections on four adult specimens were performed. Both intradural and extradural courses of C2 were studied in detail. The tentative site of C2 nerve root compression during placement of C1 lateral mass screws was studied in detail. Both the indication as well as the ease of C2 neurectomy were studied in relation to postoperative compression and entrapment.ResultsFour-six dorsal rootlets of C2 nerve were observed while studying the intradural course. The extradural course was studied with respect to the lateral mass of C1. The greater occipital nerve (GON) course was fairly consistent in all specimens. Transection of C2 around its ganglion would allow for proper C1 lateral mass screw placement as the course of C2 nerve interferes with proper placement of instrumentation.ConclusionC2 nerve root transection is associated with occipital numbness but this often has no effect on health-related quality of life (HRQOL). The C2 nerve root preservation is often associated with entrapment neuropathy or occipital neuralgia, which greatly affects HRQOL. The C2 nerve root transection helps in better visualization, aids in optimal placement of C1 lateral mass screws, minimizes estimated blood loss and improves surgical outcome with successful fusion.

Preoperative QCT assessment of femoral head for assessment of femoral head bone loss.

We quantified differences in trabecular volumetric bone mineral density (BMD) of the femoral head between patients with proximal femoral fractures and healthy subjects in the control group by using quantitative computed tomography (QCT) with the purpose of providing guidance for the choice of head screw in the intramedullary nail fixation. Participants suffering from intertrochanteric fractures (n=536 patients) were recruited. In addition, 497 fracture-free, age-matched cases were considered as the control group. The volumetric BMD of different regions of interest (ROI) in the proximal femur scanned by QCT were analyzed between the fracture and control groups. BMD of proximal femur in the fracture group was markedly lower than that in the control group. There were significant differences at distinct regions for male and female between the two groups. Furthermore, the trend of BMD changes among the femoral head, femoral neck and intertrochanter were not parallels in terms of their average value. In conclusion, osteoporosis has been demonstrated to be a main risk factor of the proximal femoral fracture. BMD value of proximal femur was often inconsistent with that of femoral head. Given this, preoperative QCT assessment plays an important role in choosing proper head screw in the intramedullary nail fixation.

The Scaphoid Safe Zone: A Radiographic Simulation Study to Prevent Cortical Perforation Arising from Different Views.

PurposeThe purpose of this study was to simulate and calculate the probability of iatrogenic perforation of the scaphoid cortical bone when internal fixation appeared to be safe on radiographs. The results will assist surgeons in determining proper screw placement.MethodsThirty scaphoids were reconstructed using computed tomography data and image-processing software. Different central axes were determined by the software to simulate the surgical views. The safe zone (SZ) and risk zone (RZ) were identified on the axial projection radiographs by comparing the scaphoid bone stenosis measured by the fluoroscopic radiographs with a three-dimensional reconstruction of the scaphoid stenosis. Each original axial projection radiograph was zoomed and compiled to match a calculated average image. The RZ, SZ, and probability of perforations in various quadrants were calculated.ResultsUsing a volar view (approach), the mean risks of cortical perforation were 25% with screws and 36% with k-wires. Using a dorsal view (approach), the mean risks of cortical perforation were 18% with screws and 30% with k-wires. A high risk of perforation was detected at the ulnar–dorsal zone.ConclusionSurgeons should be wary of screws that appear to lie close to the scaphoid cortex on both anteroposterior (AP) and lateral radiographs, particularly in the ulnar–dorsal and radial–dorsal quadrants, because such screws are likely to perforate the cortex. The position of the internal fixator should be assessed using a diagram outlining the various SZs. Therapeutic, Level III.

Vakaya Uygun Mini Vida Seçimi

Vakaya Uygun Mini Vida Seçimi

Technique Tip.

Level V.

Comparison of outcomes after atlantoaxial fusion with C1 lateral mass-C2 pedicle screws and C1-C2 transarticular screws.

To compare the clinical and radiological outcomes of posterior atlantoaxial fixation and fusion using C1 lateral mass-C2 pedicle screws (screw-rod constructs, SRC) with C1-C2 transarticular screws (TAS). A retrospective review was conducted of 105 patients with atlantoaxial instability who underwent posterior C1-C2 fixation and fusion by SRC group (60 pt) and TAS group (45 pt). The follow-up period was minimum 2years. Clinical outcomes measurements included the Numeric Rating Scale (NRS) for pain assessment, the Neck Disability Index (NDI), the Japanese Orthopedic Association (JOA) score and the American Spinal Injury Association (ASIA) impairment scale for the functional and neurological outcomes that were assessed. Radiological outcomes were assessed by evaluating the fusion rate and proper screws position. Both outcomes were evaluated in the early postoperative period, 3, 6, 12 and 24months after surgery. Operative time, estimated blood loss, complications and length of stay were also reviewed. The majority of cases were caused by trauma and presented with axial neck pain. The improvement of NRS, NDI, JOA score and ASIA impairment scale were not different between the two groups. Proper screw position and fusion rate were also observed similarly between the two groups. Estimated blood loss was lesser and operative time was shorter in TAS group than SRC group (p=0.047, p=0.001, respectively). Operative complications and the length of hospital stay were also not different between the two groups. Both SRC and TAS produced excellent outcomes for atlantoaxial stabilization. But the volume of bleeding and operation time tended to be better in TAS group compared to SRC group.

Minimally Invasive Spine Surgery for Unstable Thoracolumbar Burst Fractures: A Case Series

Introduction Traumatic thoracolumbar burst fracture is a common pathology without a clear consensus on best treatment approach. Minimally invasive approaches are being investigated due to potential benefits in recovery time and morbidity. We examine long-term resolution of symptoms of traumatic thoracolumbar burst fractures treated with percutaneous posterior pedicle screw fixation. Methods Retrospective clinical review of seven patients with spinal trauma who presented with thoracolumbar burst fracture from July 2012 to April 2013 and were treated with percutaneous pedicle screw fixation. Electronic patient charts and radiographic imaging were reviewed for initial presentation, fracture characteristics, operative treatment, and postoperative course. Results The patients had a median age of 29 years (range 18 to 57), and 57% were men. The median Thoracolumbar Injury Classification and Severity Scale score was 4 (range 2 to 9). All patients had proper screw placement and uneventful postoperative courses given the severity of their individual traumas. Five of seven patients were reached for long-term follow-up of greater than 28 months. Six of seven patients had excellent pain control and stability at their last follow-up. One patient required revision surgery for noncatastrophic hardware failure. Conclusion Percutaneous pedicle screw fixation for the treatment of unstable thoracolumbar burst fracture may provide patients with durable benefits and warrants further investigation.