Anterior Spine Research Articles

Improving blood product utilization at an ambulatory surgery center: a retrospective cohort study on 50 patients with lumbar disc replacement

BackgroundThere is minimal literature discussing anterior lumbar spine surgery in ambulatory surgery centers (ASCs). The main concern with the anterior approach to the lumbar spine is the potential for injury to great vessels. In our facility, there are two units of crossmatched blood available in addition to cell saver during the procedure. We retrospectively looked at 50 cases of lumbar total disc arthroplasty (TDA) in our ASC to determine utilization of blood products.MethodsMedical records of 50 consecutive patients who underwent a lumbar TDA at a single ASC were reviewed. Surgeries completed at the ASC were all transferred from the post anesthesia care unit to an attached convalescence care center which allows up to 3 days of observation. Patients who had either a 1 or 2 level lumbar TDA were included in the study. Data consisting of demographics, American Society of Anesthesiologist Physical Status Classification System, length of stay, estimated blood loss, cell saver volume, transfusion, perioperative and postoperative complications were recorded. Preoperative, perioperative and postoperative medical records were reviewed.ResultsMedical records of 50 consecutive patients were reviewed. The mean age was 40.86 ± 9.45. Of these, 48 (96%) had a 1-level lumbar TDA, 1(2%) had a 2-level lumbar TDA, 1 (2%) had a lumbar TDA at L4/5 and an anterior lumbar interbody fusion at L5/S1. There were no mortalities; no patient had recorded perioperative complications. No patients received allogeneic blood transfusion, 4 (8%) were re-transfused with cell saver (2 receiving approximately 400 ml and 2 receiving approximately 200 ml of re-transfused blood). All 50 (100%) were discharged home in stable condition. We had 30-day follow-up data on 35 of 50 patients. Of the 35 patients reviewed, three (8.5%) of the patients were readmitted to the hospital. One additional patient was seen in the emergency department and discharged home after negative testing. No patient was readmitted for post-operative anemia.ConclusionThe routine use of both cell saver and crossmatched blood in the operating suite for lumbar TDA may be an over-utilization of healthcare resources. In our review of 50 patients, we had no need for transfusion of allogeneic packed red blood cells (PRBCs) and only four of the 50 patients had enough blood output for re-transfusion from the cell saver. This opens the conversation for alternatives to crossmatched PRBCs being held in the operating room. Such alternatives may be the use of cell salvage, only type O blood in a cooler for each patient or keeping type O blood on constant hold in ASCs.

Predictors and Outcomes of Paramedian Incisional Hernia After Anterior Spine Exposure

BackgroundAnterior exposures for lumbar spine surgery are increasingly common for treating various spinal pathologies. A retroperitoneal approach via a paramedian incision has grown rapidly in popularity, but little is known about the risk of incisional hernia development with this technique. We sought to assess the incidence of paramedian incisional hernia development and identify risk factors that are associated with occurrence. Materials and methodsWe conducted a retrospective review of all patients who underwent anterior lumbar spine exposure by a paramedian approach between 2012 and 2017 at a single, tertiary medical center. The primary outcome was the development of postoperative paramedian incisional hernia. ResultsOf the 735 patients included in the study, 445 (60.5%) were women, and the mean (standard deviation) age of all patients was 60 y (12.4). Nearly all (97.4%) paramedian approaches were performed with a vascular surgeon present. Median follow-up time was 10 mo (interquartile range 3.5-19.9). Postoperative paramedian hernia developed in 20 patients (2.7%), of which 14 underwent repair. The mean (standard deviation) size of the hernia was 13.5 cm (5.5); 9 of 14 (64%) were repaired with synthetic mesh, whereas 3 of 14 (21%) required bowel resection. On multivariate analysis, risk factors associated with hernia development were male gender (0.045), higher American Society of Anesthesiologists class (0.039), history of abdominal surgery (P = 0.013), and postoperative intensive care unit admission (P = 0.02). ConclusionsA paramedian approach for anterior lumbar spine exposure resulted in a low rate of incisional hernia with minimal morbidity. Surgeons involved in these collaborative procedures should consider the risk factors that predispose patients to develop these hernias.

P77. Enhanced perioperative care decreases cost after major spinal surgery

BACKGROUND CONTEXT Enhanced recovery after surgery (ERAS) standardizes surgical care, reducing unnecessary variation. The goals are outcome improvement and secondarily cost reduction. ERAS has been applied successfully to many different surgical specialties but not yet comprehensively to spinal surgery. PURPOSE The purpose of this study is to investigate the financial effectiveness of an enhanced perioperative care pathway (EPOC) on patients undergoing elective major spinal surgery compared with patients receiving traditional perioperative care. STUDY DESIGN/SETTING Retrospective cohort comparison. PATIENT SAMPLE Patients undergoing elective major spinal surgery at a quaternary academic spine center. OUTCOME MEASURES Financial measures were direct costs B, separated into those expected not to change such as implant and supply costs, and direct costs A such as bed, nursing, pharmacy, imaging, laboratory, pathology and perioperative services. Indirect costs, noted as shared patient resources such as patient transport, environmental services, resident salaries and interpreter services, were also analyzed. Secondary outcome measures were hospital and intensive care length of stay. METHODS Consecutive adults undergoing major elective spine surgery were identified to be placed into the enhanced perioperative care pathway. Major spine surgery was identified utilizing CPT and ICD codes that represented, arthrodesis for deformity, anterior lumbar spine surgery greater than two levels or posterior lumbar greater than 3 levels, corpectomy in any area of the spine or pelvic fixation. Patients with significant medical comorbidities were also included. Two comparison groups were made. First, a historical cohort of patients from prior to EPOC implementation was identified as the TRDC or traditional care group. Second, a concurrent cohort of patients that failed to make entry into EPOC due to patients not attending preoperative sessions, scheduling conflicts or insurance authorization issues. This second group was labeled the Nopathway care or NOPC group. Briefly the EPOC pathway focused on coordination of preoperative care, patient counseling, and medical optimization before surgery. Carbohydrate loading preoperativley and nasal povidone iodine swabs were also utilized. Preoperative multi-modal analgesia was initiated with acetaminophen and gabapentin. Intraoperatively, focus on goal-directed fluid management, continuation of multi-modal analgesia with the addition of ketamine, and selective use of tranexamic acid. Postoperatively, oral intake was encouraged early, as well as early ambulation. Also ketamine, acetaminophen and gabapentin were continued post-operatively. Costs were broken into Direct A, B and indirect costs and analyzed using two-tailed t-tests. The TRDC cohort costs were adjusted for inflation. Length of stay was analyzed using student's t-test with equal variances not assumed. RESULTS A total of 620 patients had EPOC care. Among them, 183 and 129 patients received TRDC or NOPC, respectively. Total cost decreased by $19,344 after pathway in comparison to the TRDC group. Total cost decreased $5,889 comparing EPOC to a concurrent NOPC group. Direct costs B, implant and supply, were similar between NOPC and EPOC, however there was a small difference between TRDC and EPOC, possibly explained by the time difference in surgical care. There was a significant cost savings when comparing EPOC to TRDC and NOPC for other Direct costs (A) of $11,160 and $4,102, respectively. Hospital length of stay was significantly lower in EPOC than in both TRDC and NOPC. Similarly EPOC patients had significantly lower intensive care length of stay than both TRDC and NOPC. CONCLUSIONS Implementation of an ERAS strategy such as EPOC decreases cost and length of stay in patients undergoing major spine surgery. Length of stay was significantly lowered at both the intensive care and overall hospital level. The implementation of an EPOC pathway also achieved direct, indirect and total cost savings in elective major spine surgery. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

136. Biomechanical study of the sacral replacement part as a model for spinopelvic reconstruction following total sacrectomy

BACKGROUND CONTEXT Total sacrectomy is usually performed when a sacral tumor involves high-level sacral vertebra. Following total sacrectomy, the continuity between the spine and pelvis is necessary for ambulation, and to enable patients to resume daily living activities sooner during rehabilitation. PURPOSE The aim of this study is to assess the biomechanical properties of a novel spinopelvic reconstruction system following total sacrectomy: a sacral solid porous titanium replacement part manufactured through a rapid prototyping technique (EBM, electron beam melting). STUDY DESIGN/SETTING Biomechanic study. METHODS Three studies were carried out: with finite element methods (FEM), fatigue with a polyamide model, and in cadaver. The following models were compared in the FEM study: (1) two connected rods in L, L3-L5 pedicle screws, and two bilateral iliac screws; (2) Model 1 with no L3 fixation; (3) two connected rods in L, two screws to the L5 body and L3-L5 pedicle screws; (4) Model 3 with no L3 fixation; (5) sacral replacement part connected to the L5 body with two screws and two bilateral iliac screws, pedicle screws in L4-L5, and two vertical rods that connect them to the part; (6) Model 5 with a trans-iliac fixation rod. The L5 (mm) vertical drop, the Von Mises stress (Nm), and stress distribution were assessed. In the other studies, Model 5 was evaluated, checking the existence of errors in the instrumentation. RESULTS The areas of maximum stress were located in the connection between L5 and the pelvis in all the models. No errors were detected in the fatigue with a polyamide model studies nor in cadaver. CONCLUSIONS Significant reductions of tension and vertical displacements were achieved with the sacral replacement part as well as the lowest values published to date; this indicates that the assembly is rigid and stable, preventing the collapse of the spine on the pelvis. With the tensions obtained with the replacement part–112 MPa there is no risk of breaking when exposed to static loads nor fatigue behavior of the implants, as opposed to the other assessed and published models. Once implanted, the replacement part could show good behavior by reconstructing the anterior spine, preventing overloads in the spine or pelvis, increasing fusion rates, potentially reducing the number of check-up surgeries due to instrumental breaking down, and allowing early mobilization of the patient. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Challenges in the design and regulatory approval of 3D-printed surgical implants: a two-case series

Additive manufacturing or three-dimensional (3D) printing of metal implants can provide novel solutions for difficult-to-treat conditions, yet legislation concerning patient-specific implants complicates the implementation of these techniques in daily practice. In this Article, we share our acquired knowledge of the logistical and legal challenges associated with the use of patient-specific 3D-printed implants to treat spinal instabilities. Two patients with semiurgent cases of spinal instability presented to our hospital in the Netherlands. In case 1, severe kyphotic deformity of the thoracic spine due to neurofibromatosis type 1 had led to incomplete paralysis, and a strong metallic strut extending from C6 to T11 was deemed necessary to provide long-term anterior support. In case 2, the patient presented with progressive paralysis caused by cervicothoracic dissociation due to vanishing bone disease. As the C5-T1 vertebral bodies had mostly vanished, an implant spanning the anterior spine from C4 to T2 was required. Because of the complex and challenging nature of both cases, conventional approaches were deemed inadequate; instead, patient-specific implants were designed with use of CT scans and computer-aided design software, and 3D printed in titanium with direct metal printing. For each implant, to ensure patient safety, a comprehensive technical file (describing the clinical substantiation, technical and design considerations, risk analysis, manufacturing process, and labelling) was produced in collaboration with a university department certified for the development and manufacturing of medical devices. Because the implants were categorised as custom-made or personalised devices under the EU Medical Device Regulation, the usual procedures for review and approval of medical devices by a notified body were not required. Finite-element analyses, compression strength tests, and cadaveric experiments were also done to ensure the devices were safe to use. The planning, design, production, and insertion of the 3D-printed personalised implant took around 6 months in the first patient, but, given the experience from the first case, only took around 6 weeks in the second patient. In both patients, the surgeries went as planned and good positioning of each implant was confirmed. Both patients were discharged home within 1 week after the surgery. In the first patient, a fatigue fracture occured in one of the conventional posterior fusion rods after 10 months, which we repaired, without any deformation of the spine or signs of failure of the personalised implant observed. No other adverse events occurred up to 25 months of follow-up in case 1 and 6 months of follow-up in case 2. Patient-specific treatment approaches incorporating 3D-printed implants can be helpful in carefully selected cases when conventional methods are not an option. Comprehensive and efficient interactions between medical engineers and physicians are essential to establish well designed frameworks to navigate the logistical and regulatory aspects of technology development to ensure the safety and legal validity of patient-specific treatments. The framework described here could encourage physicians to treat (once untreatable) patients with novel personalised techniques. Interreg VA Flanders-The Netherlands programme, Applied and Engineering Sciences research programme, the Netherlands Organisation for Scientific Research, and the Dutch Arthritis Foundation VIDEO ABSTRACT.

Fatty corner lesions in T1-weighted magnetic resonance imaging as an alternative to sacroiliitis for diagnosis of axial spondyloarthritis

BackgroundA fatty corner lesion (FCL) is a well-demarcated fat infiltration in the corner of a vertebral body on T1 magnetic resonance imaging (MRI) sequence. It has been reported to be useful in the diagnosis of axial spondyloarthritis (axSpA). Our objective is to systematically evaluate the diagnostic accuracy of FCLs in tertiary centre patients with chronic back pain.MethodTwo hundred and thirty eight axSpA patients and 62 non-axSpA patients with back pain were recruited from five rheumatology centres. Clinical, biochemical, and radiological parameters were collected and all patients underwent a MRI of the spine and sacroiliac (SI) joints. FCLs in vertebral bodies from C4 to L5 were scored. The number and location of FCLs were clustered together to determine an optimal combination for diagnosis. Results were compared with expert diagnosis as the “gold standard”.ResultsFCLs of the anterior whole spine (AUC 0.62; p = 0.003) and anterior thoracic spine (AUC 0.64; p = 0.001) had diagnostic significance. Incorporating at least 5 whole spine FCLs into the imaging criteria of the Assessment of SpondyloArthritis international Society (ASAS) criteria for axSpA yielded a sensitivity of 91.6% and specificity of 91.9%. Similarly, applying at least 3 anterior thoracic FCLs to the imaging criteria of the ASAS axial SpA criteria yielded a sensitivity of 92.0% and specificity of 93.5%.ConclusionFCLs could be used to diagnose axial SpA. The presence of at least 3 anterior thoracic FCLs in T1-weighted MRI spine suggests a diagnosis of axial SpA without additional MRI of the SI joints.Trial registrationThe cohort has been registered in the clinical trial registry of the University of Hong Kong (HKUCTR-2087).

Study on the Morphology of Fasciola gigantica and Economic Losses due to Fasciolosis in Berau, East Kalimantan

Fasciolosis is one of the endemic parasitic diseases in Indonesia and causes significant economic losses. Fasciola gigantica is the main species found to infect livestock. This research aimed to describe the morphology of F. gigantica histologically using hematoxylin and eosin staining as well as ultrastructure morphology using scanning electron microscopy (SEM). Besides, the study was also carried out to determine the prevalence and estimation of economic losses due to fasciolosis in Berau Regency. The histological identification of flukes morphology found several organs including oral sucker (OS), ventral sucker (VS), cirrus (C), genital pore (GP), uterus (U), ovary (O), tegument (Te), testis (T), and caecum (C). In this study, ultrastructure morphology was divided into anterior and midbody region. In the anterior region, there are an oral sucker (OS) with a diameter of 304.5 µm and a ventral sucker (VS) with a diameter of 571 µm. It was also found the anterior spine with a width of 25.4 µm and a height of 22.8 µm. In the midbody, the spine has a width of ± 26.7 µm and a length of ± 38.9 µm leading posteriorly. Postmortem examination results showed that the prevalence of fasciolosis in Berau regency was 21.65% or 34 of 157 cows which were positive with an estimated loss of 228,656,475.00 IDR/16,450 USD (1 USD=13,900 IDR). The amount of loss due to fasciolosis must be a particular concern in carrying out control and prevention measures. Histology and ultrastructure morphology can become a reference in the development of anthelmintic testing that has been used so far in Indonesia.

Optimization of treatment of patients with tuberculosis spondylitis

Tuberculosis spondylitis is 40–61.5 % in the structure of bonearticular tuberculosis in adults. Objective: to increase the efficiency of treatment of patients with tuberculous spondylitis of the thoracic and lumbar spine. Methods: the results of treatment of 60 patients with active tuberculosis spondylitis were analyzed. At the group (n = 30) — at the stage of preoperative preparation were prescribed an intensive course (2–3 weeks) of specific antibacterial therapy taking into account the results of bacteriological sensitivity of microbacterial tuberculosis to antibacterial drugs; then surgical treatment was made with telescopic titanium cages for the front spine fusion. Group II (n = 30) — got 3–5 specific antibacterial for 2–3 months; subsequent surgical intervention involving the usage of autografts for the anterior spine fusion. The groups were identical in age, sex, number of affected vertebral motor segments, and activity of the infectious inflammatory process. Results: excellent in the long follow-up period were obtained in 14 (54 %) patients in the 1st group and 8 (32 %) — II, good in 1 (24.7 %) and 7 (28 %); satisfactory — at 4 (15.4 %) and 7 (28 %) respectively. Only 3 (12 %) patients in group II were shown unsatisfactory results. Conclusions: the proposed method of surgical treatment of tuberculosis spondylitis with the usage of modern achievements (the use of telescopic titanium cages) after short-term intensive antibacterial therapy, taking into account etiological diagnosis, is considered to be promising. In patients of group I, the results of treatment were significantly better due to a significant shortening of pre-surgery period, reducing the number of complications, reducing the timing of inpatient treatment and improving the quality of life.

Hammering reverse guide wire technique for safe placement of anterior column retrograde in-tramedullary screw in pelvic and acetabular surgery

Objective To evaluate the efficacy and accuracy of hammering reverse guide wire technique for safe placement of anterior column retrograde intramedullary screw in pelvic and acetabular surgery. Methods From September 2015 to March 2018, 46 patients with pelvic or/and acetabular fracture involving the anterior column were treated with hammering reverse guide wire technique for safe placement of anterior column retrograde intramedullary screw at Department of Orthopaedics, Lishui Municipal Central Hospital. They were 28 men and 18 women, aged from 21 to 85 years (mean, 55.6 years). There were 34 pelvic ring fractures, 9 acetabular fractures and 3 combined pelvic ring and acetabular fractures. After the anterior lateral spine of pubic tuberosity was drilled by a guide pin and drill bit as the entry point, a reverse guide wire was knocked into the bone lightly by a hammer. For each retrograde intramedullary screwing into the acetabular anterior column, we recorded operation time, fluoroscopic frequency, and attempts to establish an acceptable screw pathway by the guide pin. The accuracy of screwing and the quality of fracture reduction were evaluated by imaging examination. For each patient, we recorded fracture union time and complications. Functional recovery of the pelvis and acetabulum was assessed by postoperative physical examination at the last follow-ups. Results The operation time of retrograde intramedullary screwing for the 46 patients averaged 28.9 minutes (from 16 to 55 minutes); the fluoroscopy frequency averaged 16.3 times (from 9 to 35 times); an acceptable screw pathway was established by the first attempt in 43 of the 46 patients (93.5%) and re-established after adjustment of the guide pin in the other 3. Forty patients were followed up for an average of 15.2 months(from 6 to 36 months). Postoperative CT scan and three-dimensional reconstruction showed that all the screws had been placed safely and accurately in the acetabular anterior column. Implant loosening and fracture displacement occurred in one case and lower limb thrombosis in another. No nail breakage, fracture nonunion, incision necrosis or infection, neurovascular injury or femoral head necrosis was observed. All fractures united after an average of 14.7 weeks (from 12 to 18 weeks). According to the Majeed scoring at the last follow-ups, the pelvic and acetabular function was evaluated as excellent in 29 cases, as good in 9, and as fair in 2, giving an excellent and good rate of 95.0%. Conclusion Hammering reverse guide wire technique is an effective method for safe placement of anterior column retrograde intramedullary screw in pelvic and acetabular surgery, because it can increase accuracy of screwing and reduce intraoperative radiation, operation time and incidence of complications though it is simple. Key words: Pelvis; Acetabulum; Fractures, bone; Surgical procedures, minimally invasive; Fracture fixation, internal

Exploration of robotic-assisted surgical techniques in vascular surgery.

Robotic-assisted surgical approaches for vascular surgery are feasible regarding minimally invasive exposure, dissection, ligation and skeletonization for varicose vein ligation, anterior spine exposure, femoral-popliteal bypass, femoral vein harvest and aortic aneurysm repair. The authors performed a cadaveric exploration to demonstrate proof of concept and feasibility for a robotic-assisted approached. Surgeon autonomy over endoscopic vision, robotic instrumentation and retraction were noted as key benefits over existing open vascular approaches. Robotic-assisted approaches for vascular surgery enable innovative minimally invasive approaches to disease states not amenable to endovascular repair. Potential reductions in paresthesia through nerve identification were noted during a cadaveric exploration for varicose vein ligation in the setting of chronic venous insufficiency. Minimally invasive femoral artery exposure via a retroperitoneal approach could potentially reduce the morbidity associated with the traditional groin incision. Further exploration and procedure refinement are warranted.

Effects of waterborne luteinizing hormone and follicle-stimulating hormone on reproduction of the rotifer Brachionus calyciflorus (Monogononta: Brachionidae)

This study used freshwater rotifers to evaluate the effects of two endocrine disrupting compounds (EDCs), luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which can be considered emergent contaminants in urban and rural wastewater and are of ecotoxicological importance. LH stimulates the synthesis of testosterone, whereas FSH promotes the maturation of follicles and sperm in vertebrates and invertebrates. However, in rotifers, there are no reports of the effects of chronic exposure to these hormones when added to reconstituted culture medium, as a way to study potential adverse effects that might occur in the environment. Therefore, we studied the reproductive effects of the rotifer Brachionus calyciflorus Pallas 1766 using a 4-day reproductive assay. Our results indicate that LH has a significant effect in increasing the production of females, males, and cysts, while FSH had no significant effect compared to control treatment. Additionally, our results indicate that LH exposure resulted in 0.33% of organisms being deformed, whereas FSH exposure resulted in 1.09% of organisms being deformed. Deformations included: (a) abnormal growth of lorica, (b) joined foot-head, (c) deformed anterior spine, and (d) deformed parthenogenetic eggs. The organisms with LH-induced deformations did not reproduce and only lived 48 h after 4 days of exposure, while those with FSH-induced deformities survived 15 days and produced 105 cysts with a hatching percentage of 58.10%. Our goal was to contribute to the knowledge of endocrine systems and endocrine hormones of rotifers, to explain the potential mechanism of endocrine disruption that results in adverse effects in freshwater rotifers.

Development of mathematical methods for calculation of the pubic arch angle

Hypothesis/aims of study. The frequency of adverse intranatal outcomes is significantly increased when the pubic arch angle (PAA) is less than 90°. The accuracy of the manual method for determining PAA depends on a large number of parameters, such as obesity of a woman, as well as stereometric sensation and the experience of a doctor. Determination of PAA using ultrasound and X-ray pelviometry is generally available and reliable; however, it requires special training. The aim of this study was to develop mathematical methods for calculation of PAA.
 Study design, materials and methods. The study included a retrospective and prospective analysis of 120 birth histories based on the Regional Clinical Hospital Perinatal Center (the Chita city, the years 2017/2018), which were divided into three equal groups. Group 1 consisted of patients with body weight deficit, group 2 included patients with normal body mass index, and group 3 comprised patients with alimentary constitutional obesity. On the eve of the birth, external pelviometry, the manual method for determining PAA, and ultrasound pelviometry by translabial access were performed.
 Results. PAA determined by the manual method was 99.6 ± 11.3° in group 1, 100.1 ± 14.2° in group 2, and 98.2 ± 10.7° in group 3. When ultrasound pelviometry was performed, the value of PAA was 97.4 ± 10.7° in group 1, 104.8 ± 13.8° in group 2, and 104.1 ± 12.3° in group 3. The error of the manual method was 2.2% in group 1, 4.5% in group 2, and 7.6% in group 3. On the basis of mathematical modeling of external pelviometry data, a pattern is defined, which is expressed by the formula: PAA = 180° – arccos (0,5 ∙ S1S2/S1P) – arccos (0,5 ∙ B1B2/(B2S1 – S1P), where PAA is the pubic arch angle (°); S1S2, Distantia spinarum; S1P, the distance between the anterior superior spine of the ilium to the lower edge of the symphysis; B2S1, the distance between the anterior superior spine of the ilium to the tuberosity of the opposite ischium; B1B2, the transverse size of the output plane. The coefficient of determination (R-squared) is 0.82. Thus, mathematical modeling allows determining PAA with a high degree of reliability.

Three-dimensional (3D) Printing Technology Assisted by Minimally Invasive Surgery for Pubic Rami Fractures.

The feasibility of three-dimensional (3D) printing technology combined with minimally invasive surgery in the treatment of pubic rami fractures was explored. From August 2015 to October 2017, a series of 30 patients who underwent surgical stabilization of their anterior pelvic ring (all utilizing the 3D printing technology) by one surgeon at a single hospital were studied. The minimally invasive incisions were made through anterior inferior cilia spine and pubic nodule. Data collected included the operative duration, the blood loss, the damage of the important tissue, the biographic union and the recovery of the function after the operation. Measurements on inlet and outlet pelvic cardiograph were made immediately post-operation and at all follow-up clinic visits. The scores of reduction and function were measured during follow-up. Results showed that the wounds of 30 patients were healed in the first stage, and there was no injury of important structures such as blood vessels and nerves. According to the Matta criteria, excellent effectiveness was obtained in 22 cases and good in 8 cases. According to the functional evaluation criteria of Majeed, excellent effectiveness was obtained in 21 cases and good in 9 cases. It was suggested that the 3D printing technology assisted by minimally invasive surgery can better evaluate the pelvic fracture before operation, which was helpful in plate modeling, and can shorten surgery duration and reduce intraoperative blood loss and complications. The positioning accuracy was improved, and better surgical result was finally achieved.

Acute Effects on TH4 Thoracic Spine Mobilisation Techniques on the Sympathetic Nervous System - a Cross-Over Feasibility Study

Acute Effects on TH4 Thoracic Spine Mobilisation Techniques on the Sympathetic Nervous System - a Cross-Over Feasibility Study Abstract. Up to date, empiric evidence about effects of thoracic spine mobilisation (TH4) on the sympathetic nervous system is lacking. The primary goal of this feasibility study was to determine adherence rate, side effects and the protocol as well as the implementation of the study design. The secondary goal was to analyse and interpret acute effects on the sympathetic nervous system after thoracic mobilisation in anterior thrust and posterior thrust on six healthy participants on two following days. The feasibility of this study was adequate. The spine mobilisations did not produce any adverse effects. The anterior thrust spine mobilisations showed a tendency in reducing the heart rate activity.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P39. Modic 2 changes and smoking predict vascular adherence during anterior lumbar exposure

BACKGROUND CONTEXT An anterior approach to access lumbar intervertebral discs risk major vascular injury and significant bleeding. We aimed to identify predictive factors for vascular adherence to allow pre-operative planning and technique modification. METHODS Retrospective analysis of a prospectively collected database was performed of consecutive patients undergoing anterior retroperitoneal exposure for lumbar disc surgery from 2009 to 2016. Data collected included demographic factors, smoking status, MRI findings, operative parameters and difficulty of dissection due to vascular adherence (standard or difficult). Smokers were defined as those currently smoking or had ceased smoking within 6 months of operation. Exclusion criteria were morbid obesity, previous anterior spine surgery or radiotherapy. RESULTS Multivariate analysis of 246 patients (mean age 42.5years (21–80), male 50%) demonstrated two statistically significant risk factors – Modic 2 changes on MRI (P=.009) and smoking status (p=.007). Of 57 patients with Modic 2 changes at the operative level, 16 had a difficult dissection due to vascular adherence (28%). Of 189 patients without Modic 2 changes, only 25 patients had a difficult dissection (13%) (p=.014). Patients with Modic 2 changes were 2.1times more likely to have vascular adherence.Of 125 nonsmoking patients, 13 had a difficult dissection (10%). Of 83 ex-smokers, 19 had a difficult dissection (23%) and of 38 current smokers, nine had a difficult dissection (24%). Overall, of the 121 smokers (ex- and current), 28 had a difficult dissection (23%) (p=.01). Patients with any smoking history were 2.2times more likely to have vascular adherence. CONCLUSIONS Modic 2 changes on MRI and any smoking history predicted adherence of the large vessels to the anterior disc annulus leading to a more difficult dissection. These two predictors should alert the surgeon to the potential for a challenging dissection and major vascular injury.

Thursday, September 27, 2018 8:30 AM–9:30 AM Best Papers: 107. Analysis of lumbar total disc replacement removals and revisions: a 17-year experience

BACKGROUND CONTEXT One concern expressed about lumbar total disc replacement (TDR) has been safety. One measure of safety is the need for subsequent surgery to removal or revise an implant. This may be of particular importance considering TDR removal or revision generally requires re-operation through the anterior approach with the corresponding increased risk of vascular injury. PURPOSE The purpose of this study was to analyze the incidence of, and reasons for, removal or revision of lumbar TDR devices. STUDY DESIGN/SETTING Data were collected from a multi-site spine specialty practice. PATIENT SAMPLE A consecutive series of 1,707 lumbar TDR patients, beginning with the first case experience in 2000, was reviewed to identify those undergoing re-operation for TDR removal or revision. Only patients who were at least 6 months postoperative were included. Among the 1,707 patients, the mean follow-up was 42.7 months with a median of 30 months and a maximum of 195 months. OUTCOME MEASURES The primary outcome measure was the occurrence of a surgery for the revision or removal of a lumbar TDR. METHODS For each case of device removal/revision, the reason, duration from index surgery, and procedure performed were recorded. Six different devices were used in the series. RESULTS In the series of 1,707 patients, there were 17 patients who underwent TDR removal (0.99%) and three additional patients underwent TDR revision (0.17%). The rates based on the total number of 2,023 TDR devices implanted in the 1,707 patients, were 0.89% removals and 0.15% revisions. The reasons and timing of removal/revisions were analyzed. Removals included: eight for migration and/or loosening, three developed problems after a trauma, one had vertebral body fractures (osteoporosis), one TDR was too large and replaced with smaller device, one had ongoing pain, and one had an infection seeded from a chest infection at 146 month post-TDR. Revisions included one repositioning the core (technique error), one repositioned device after displacement, and one core replacement due to wear or failure. With respect to timing, 40% of removals or revisions occurred within one month after the index surgery, and a total of 85% occurred within 2 years. Of note, 40% of the revisions/removals occurred in the first 25 TDR cases performed by individual surgeons. There were no vascular complications causing clinical sequelae during the removal or revision surgeries. CONCLUSIONS In this large patient series, 1% of lumbar TDRs were removed or revised. Only one revision was related to device failure or wear. Many of the subsequent procedures were performed within a month of implantation. Also of note, many occurred within the first 25 TDR cases for individual surgeons, suggesting a learning curve. In cases of TDR removal or revision, as with any repeat anterior spine surgery, one should be acutely aware and prepared for vascular injury should it occur. The low rate of removal or revision in this large institutional experience over a 17 year period provides support for the safety of these devices. FDA DEVICE/DRUG STATUS Charite, ProDisc-L, and activL approved for single-level use; Kineflex-L, Freedom, and Flexicore investigational; and Charite, ProDisc-L, and activL off-label for multi-level and hybrid.

Phylogeny and Taxonomy of Flatheads, Scorpionfishes, Sea Robins, and Stonefishes (Percomorpha: Scorpaeniformes) and the Evolution of the Lachrymal Saber

We report on the discovery of a remarkable defensive specialization in stonefishes that was identified during a phylogenetic study of scorpionfishes and their relatives. This newly described innovation, the lachrymal saber, involves modifications to the circumorbitals, maxilla, adductor mandibulae, and associated tendons. At its core, the lachrymal saber is an elongation of an anterior spine (or spines) on the ventral surface of the lachrymal that stonefishes are capable of rotating from the standard ventral position to a locked lateral position. The locking mechanism minimally includes a bony spur on the inner surface of the lachrymal and a ridged bony protuberance on the anterolateral end of the maxilla. A modified and highly subdivided adductor mandibulae appears to control the movement of the lachrymal saber by rotating the maxilla while it is engaged with the spur on the medial side of the lachrymal. This maxillary rotation results in a subsequent rotation of the lachrymal that we hypothesize reduces...

SACRECTOMY ASSOCIATED WITH VERTEBRECTOMY: A NEW TECHNIQUE USING DOWEL GRAFTS FROM CADAVERS.

ABSTRACTObjective:The purpose of this study was to demonstrate, in a case series, a new sacrectomy technique using an iliac crest dowel graft from a cadaver.Study design:Report of a case series with description of a new surgical technique.Methods:The technique uses four bars to support the posterior spine and a dowel graft in the iliac wings, with compression of the spine and pelvis above it, to support the anterior spine. Three cases were operated on, and in all of them, a vertebrectomy was used.Results:In the first two cases, the technique was performed as a two-stage surgery. The first stage was performed via the anterior and peritoneal access routes, and the second stage via the posterior access route. In the third case, retroperitoneal access via the anterior route meant that the technique could be performed in one stage, resulting in an overall reduction in surgical time (1250 vs. 1750 vs. 990 minutes, respectively).Conclusion:The new technique enables fixation with biomechanical stability, which is essential to support the stress in the lumbosacral transition and promote earlier rehabilitation. Level of evidence IV, case series.

The radiologic anatomy of thyroid cartilage and cricoid cartilage: implications for anterior cervical spine surgery

Objective To measure anatomic data related to the thyroid cartilage and cricoid cartilage and to analyze their implications for anterior spine surgery. Methods From January 2015 to February 2017, Cervical spine CT image data of 309 normal adults (195 males, 114 females) in our department were retrospectively analyzed. The transverse diameters of the thyroid cartilage and the cricoid cartilage was measured at three different levels as follows: the superior border of the thyroid cartilage(SBTC), the inferior border of the thyroid cartilage(IBTC), and the inferior border of the cricoid cartilage(IBCC). At those levels, the corresponding level and transverse diameter of the cervical vertebra or intervertebral disc were also determined. Differences of anatomic parameters for each gender and level, and the relationship between the transverse diameter and height and weight were analyzed. Results The transverse diameters of the thyroid cartilage or cricoid cartilage and the corresponding cervical vertebra or intervertebral disc were associated significantly with height and weight. The transverse diameters of the thyroid cartilage or cricoid cartilage gradually decreased from the level of SBTC (44.30±4.97 mm) to the level of IBTC (41.39±4.62 mm), and the latter to the level of IBCC (26.36±3.79 mm), but increased from the level of SBTC (27.47±2.66 mm) to the level of IBTC(29.00±3.15 mm), and the latter to the level of IBCC (31.48±3.49 mm) for the cervical vertebra or intervertebral disc. Differences of the transverse diameters of the thyroid cartilage or cricoid cartilage and the cervical vertebra or intervertebral disc on three levels had statistical significance. The transverse diameters of each level had individual differences, while men were greater than those for women. The thyroid cartilage was routinely located above the C5 (56.9% for male, 86.0% for female). Differences of the frequency between men and women on three levels had statistical significance. Conclusion The Individual and sex differences in the location of the thyroid cartilage and the size of the thyroid cartilage and the cricoid cartilage provided anatomical basis for predicting the difficulty of intraoperative exposure, incidence of esophageal injuries and early postoperative dysphagia. Key words: Thyroid cartilage; Cricoid cartilage; Anatomy, regional; Spinal fusion; Deglutition disorders

Incorporation of Anterior Lumbosacral Spine Exposure into a General Surgical Practice

Many spine surgeons enlist the aid of an "access surgeon" to provide anterior exposure of the lumbosacral spine. We proposed that a single, community hospital general surgery practice can successfully develop an anterior spine exposure program with acceptable clinical outcomes. One hundred and forty-three consecutive anterior exposures were performed between 2008 and 2014. Morbidity and 30-day mortality were recorded. The effects of American Society of Anesthesiologists Physical Status classification (ASA class) and number of levels exposed on length of stay (LOS) and estimated blood loss (EBL) was reported. The growth of the program during this period was also evaluated. During the six-year period, there were nine (6.3%) major complications and 17 (11.9%) minor complications with no 30-day mortality. The mean LOS was similar for one-level and two-level exposures (3.8 days). Mean LOS was higher in ASA III patients (4.4 days) than ASA I (2.9 days) or ASA II (3.2 days). Mean EBL for one-level exposures (336.3 mL) was not significantly different than EBL for two-level exposures (425.9 mL). EBLs in ASA class III patients were greater than in class I and class II patients. The program began in July of 2008 with a single spine surgeon and one operation that year. A high of 54 procedures, with seven different spine surgeons, was recorded in 2013. A single, community hospital general surgery practice can successfully develop an anterior approach to spine exposure program with acceptable clinical outcomes and with sustained growth of the program.