Elevated blood metal ion levels in patients undergoing instrumented spinal surgery: a systematic review and meta-analysis.

BACKGROUND CONTEXT: Elevated blood metal levels have been reported in patients after spinal surgery using metallic implants. Although some studies have suggested an association between heightened blood metal concentrations and potential adverse effects, estimates of the incidence of abnormal metal levels after spinal surgery have been inconsistent. PURPOSE: The aims of this systematic review and meta-analysis were to assess: (1) mean differences in blood metal ion levels between patients undergoing spinal fusion surgery and healthy controls, (2) odds of elevated blood metal ion levels after surgery compared to pre-surgery levels, and (3) pooled incidence of elevated blood metal ions overall and by metal type. STUDY DESIGN: Systematic review and meta-analysis. PATIENTS SAMPLE: The patient sample included 613 patients from 11 studies who underwent spinal surgery instrumentation. OUTCOME MEASURES: Blood metal ion concentrations and the incidence of patients with elevated metal levels compared with in those the control group. METHODS: A comprehensive search was conducted in PubMed, EMBASE, Scopus, and Cochrane Library to identify studies reporting blood metal ion levels after spinal fusion surgery. Mean differences (MD), odds ratios (OR), and incidence rates were pooled using random effects models. Heterogeneity was assessed using I2 statistics, and fixed-effects models were used if no heterogeneity was detected. Detailed statistical analysis was performed using the Review Manager version 5.4 software. RESULTS: The analysis included 11 studies, with a total of 613 patients. Mean blood metal ion levels were significantly higher after spinal fusion surgery (MD 0.56, 95% CI 0.17-0.96; I2=86%). Specifically, titanium levels were significantly elevated (MD 0.81, 95% CI 0.32-1.30; I2=47%). The odds of elevated blood metal ions were higher after surgery (OR 8.17, 95% CI 3.38-19.72; I2=41%), primarily driven by chromium (OR 23.50, 95% CI 5.56-99.31; I2=30%). The incidence of elevated chromium levels was found to be 66.98% (95% CI 42.31-91.65). CONCLUSION: In conclusion, blood metal ion levels, particularly titanium and chromium, were significantly increased after spinal fusion surgery compared to pre-surgery levels and healthy controls. Approximately 70% of the patients exhibited elevated blood levels of chromium and titanium.

Incidence and risk factors of distal adjacent disc degeneration in adolescent idiopathic scoliosis patients undergoing fusion surgery: a systematic review and meta-analysis.

PURPOSE: The objective of this meta-analysis was to determine the incidence of disc degeneration in patients with surgically treated adolescent idiopathic scoliosis (AIS) and identify the associated risk factors. METHODS: PubMed, EMBASE, Scopus, and Cochrane Collaboration Library databases were searched. The outcomes of interest were the incidence of disc degeneration, SRS-22, and radiological risk factors. The lower instrumented vertebra (LIV) was also evaluated. Fixed effects were used if there was no evidence of heterogeneity. Statistical analysis was performed using Review Manager. RESULTS: A meta-analysis was conducted including nine studies with a total of 565 patients. The analysis revealed that the global incidence of intervertebral disc degeneration in patients with surgically treated AIS patients was 24.78% (95% CI 16.59-32.98%) 10 years after surgery, which significantly increased to 32.32% (95% CI 21.16-43.47% at an average of 13.8 years after surgery. Among patients with significant degenerative disc changes, the SRS-22 functional, self-image, and satisfaction domains showed significantly worse results (MD - 0.25, 95% CI - 0.44 to - 0.05; MD - 0.50, 95% CI - 0.75 to - 0.25; and MD - 0.34, 95% CI - 0.66 to - 0.03, respectively). Furthermore, instrumentation at or above the L3 level was associated with a lower incidence of intervertebral disc degeneration compared to instrumentation below the L3 level (OR 0.25, 95% CI 0.10-0.64). It was also found that the preoperative and final follow-up lumbar curve magnitudes (MD 8.11, 95% CI 3.82-12.41) as well as preoperative and final follow-up lumbar lordosis (MD 0.42, 95% CI - 3.81 to 4.65) were associated with adjacent disc degeneration. CONCLUSIONS: This meta-analysis demonstrated that the incidence of intervertebral disc degeneration significantly increased with long-term follow-up using fusion techniques, reaching up to 32% when patients were 28 years of age. Incomplete correction of deformity and fusion of levels below L3, were identified as negative prognostic factors. Furthermore, patients with disc degeneration showed worse functional outcomes.

Reply to Lemans et al. Comment on "Burgos et al. Fusionless All-Pedicle Screws for Posterior Deformity Correction in AIS Immature Patients Permit the Restoration of Normal Vertebral Morphology and Removal of the Instrumentation Once Bone Maturity Is Reached. J. Clin. Med. 2023, 12, 2408".

We thank Dr. Lemans and coworkers for their interest and knowledgeable comments [...].

Abolition of sagittal T7-T10 dynamics during forced ventilation in AIS patients with Lenke 1A curves.

In healthy subjects, respiratory maximal volumes are highly dependent on the sagittal range of motion of the T7-T10 segment. In AIS, the abolition of T7-T10 dynamics related to the stiffness induced by the apex region in Lenke IA curves could harm ventilation during maximal breathing. The aim of this study was to analyze the dynamics of the thoracic spine during deep breathing in AIS patients and in healthy matched controls. This is a cross-sectional, case-control study. 20 AIS patients (18 girls, Cobb angle, 54.7 ± 7.9°; Risser 1.35 ± 1.2) and 15 healthy volunteers (11 girls) matched in age (12.5 versus 15.8 years mean age) were included. In AIS curves, the apex was located at T8 (14) and T9 (6). Conventional sagittal radiographs of the whole spine were performed at maximal inspiration and exhalation. The ROM of each spinal thoracic functional segment (T1-T7, T7-T10, T10-T12) and the global T1-T12 ROM were measured. In healthy subjects, the mean T1-T12 ROM during forced breathing was 16.7 ± 3.8. AIS patients showed a T1-T12 ROM of 1.1 ± 1.5 (p < 0.05), indicating a sagittal stiffness of the thoracic spine. A wide T7-T10 ROM (15.3 ± 3.0) was found in healthy controls (91.6% of the T1-T12 ROM). AIS patients showed only 0.4 ± 1.4 ROM at T7-T10 (36.4% of the T1-T12 ROM) (p < 0.001). There was a linear relationship between the magnitude of T7-T10 kyphosis in maximal exhalation and both FVC (% of predicted FVC) and FEV1. In conclusion, Lenke 1A AIS patients show a restriction of the thoracic spine motion with an almost complete abolition of T7-T10 ROM, a crucial segment for deep breathing. T7-T10 stiffness could explain the ventilatory limitations found in AIS patients.

Fusionless All-Pedicle Screws for Posterior Deformity Correction in AIS Immature Patients Permit the Restoration of Normal Vertebral Morphology and Removal of the Instrumentation Once Bone Maturity Is Reached.

The aim of this study was to report the restoration of normal vertebral morphology and the absence of curve progression after the removal of instrumentation in AIS patients that underwent posterior correction of the deformity by a common all-screws construct without fusion. A series of 36 AIS immature patients (Risser 3 or less) were included in the study. Instrumentation was removed once the maturity stage was complete (Risser 5). The curve correction was assessed pre- and postoperatively, before instrumentation removal, directly post-removal, and more than two years after instrumentation was removed. Epiphyseal vertebral growth modulation was assessed by the coronal wedging ratio (WR) at the apical level of the main curve (MC). The mean preoperative coronal Cobb was corrected from 53.7° ± 7.5 to 5.5° ± 7.5° (89.7%) at the immediate postop. After implant removal (31.0 ± 5.8 months), the MC was 13.1°. T5-T12 kyphosis showed significant improvement from 19.0° before curve correction to 27.1° after implant removal (p < 0.05). Before surgery, the WR was 0.71 ± 0.06, and after removal, 0.98 ± 0.08 (p < 0.001). At the end of the follow-up, the mean sagittal range of motion (ROM) of the T12-S1 segment was 51.2 ± 21.0°. The SRS-22 scores improved from 3.31 ± 0.25 preoperatively to 3.68 ± 0.25 at the final assessment (p < 0.001). In conclusion, a fusionless posterior approach using common all-pedicle screws correctly constructed satisfactory scoliotic main curves and permitted the removal of instrumentation once bone maturity was reached. The final correction was highly satisfactory, and an acceptable ROM of the previously lower instrumented segments was observed.

Pulse-train versus single-pulse t-EMG stimulation for intraoperative neurophysiologic monitoring of thoracic pedicle screws in adolescent idiopathic scoliosis.

OBJECTIVE: To assess the PTS method in neuromonitoring of thoracic pedicle screws in a young cohort of AIS patients. The accuracy of both PTS (Pulse-train stimulation) and SPS (Single-pulse stimulation) techniques in the detection of misplaced thoracic screws was compared with special reference to the screws placed at the concavity and the convexity of the curve. PATIENTS AND METHODS: A single-center prospective clinical cohort study. LEVEL OF EVIDENCE II: Twelve AIS patients who underwent elective surgery were included in this study. Screw stimulation using repetitive constant-current stimulus train of variable intensities was first performed after screw insertion. SPS was performed immediately after PTS. Postoperatively, CT scan was used to check the final position of the screws. A total of 246 thoracic pedicle screws were placed. Thresholds of screws placed in the convexity and the concavity were compared. RESULTS: Invasion of the spinal canal was postoperatively confirmed in 29 of the pedicle screws. The SPS technique detected three (10.3%) of these screws using a threshold limit of 12 mA. The PTS technique detected 25 (86.2%) of the 29 misplaced screws using threshold of 30 mA (negative predictive value, 93.1%). When using a PTS threshold of < 20 mA, the positive predictive value was 70%. SPS did not detect any of the misplaced screws at the apex level of the scoliotic curves, and PTS detected 10 out of 17 of these screws. Overall, area under the ROC curve was 0.82 for PTS and 0.61 for SPS. CONCLUSIONS: PTS is a reliable method for detecting medially misplaced screws among young AIS patients undergoing scoliosis surgery. PTS provides more accurate predictions than SPS and improves the identification of screws invading the spinal canal at the apex or near the apex levels.

Cardiorespiratory function of patients undergoing surgical correction of Scheuermann's hyperkyphosis.

The aim of this study was to analyze the impact of surgical correction of the thoracic deformity on the cardiorespiratory function of patients with moderate-severe Scheuermann's hyperkyphosis (SK). A series of 23 adolescents with SK who underwent surgery through an only posterior approach using all pedicle screw constructs were included in the study. Cardiorespiratory parameters were measured during a maximal exercise tolerance test before and 2 years after surgery. Heart rate, oxygen saturation (SatO2), maximum oxygen uptake (VO2 max), ventilatory capacity at maximal exercise (VEmax), and energy costs were recorded. There were statistically significant differences in the forced vital capacity (FVC) (P < 0.05), total VO2max (ml/min) (P < 0.01), maximum expired volume (VEmax) per minute (P < 0.01) and cardiovascular efficiency (HR/VO2 ratio) (P < 0.05). None of these changes were clinically relevant. There were no changes in the VO2max per kg of body mass. The magnitude of the kyphosis correction did not correlate with the change in normalized VO2max or VEmax. In conclusion, patients with moderate-severe SK improve their baseline respiratory limitations and the tolerance to maximum exercise 2 years after surgery. However, the slight cardiorespiratory functional improvements should not necessarily be attributed to the surgery, and could also be caused solely by the residual growth of the lungs and thorax. Furthermore, respiratory functional changes are under thresholds considered as clinically relevant.

Non-uniform Segmental Range of Motion of the Thoracic Spine During Maximal Inspiration and Exhalation in Healthy Subjects.

Background and Objective: To analyse the range of motion of the thoracic spine by radiographically measuring changes in the sagittal profile of different thoracic segments during maximal inspiration and exhalation. The starting hypothesis was that forced deep breathing requires an active, but non-uniform widening of the lordotic-kyphotic range of motion of the different thoracic segments. Methods: Cross-sectional study. Participants were 40 healthy volunteers aged 21-60. Conventional anteroposterior and functional sagittal chest radiographs were performed during maximal inspiration and exhalation. The range of motion of each spinal thoracic functional segment, global T1-T12 motion, and the sagittal displacement of the thoracic column during breathing were measured. Considering the different type of ribs and their attachment the spine and sternum, thoracic segments were grouped in T1-T7, T7-T10, and T10-T12. The displacement of the thoracic spine with respect to the sternum and manubrium was also recorded. Results: The mean difference from inspiration to exhalation in the T1-T12 physiologic kyphosis was 15.9° ± 4.6°, reflecting the flexibility of the thoracic spine during deep breathing (30.2%). The range of motion was wider in the caudal hemicurve than in the cranial hemicurve, indicating more flexibility of the caudal component of the thoracic kyphosis. A wide range of motion from inspiration to exhalation was found at T7-T10, responsible for 73% of T1-T12 sagittal movement. When the sample was stratified according to age ranges (20-30, 30-45, and 45-60 yr.), none of the measurements for inspiration or exhalation showed statistically significant differences. Only changes at this level showed a positive correlation with changes in the global thoracic kyphosis (r = 0.794, p <0.001). Conclusion: The range of motion of the thoracic spine plays a relevant role in respiration dynamics. Maximal inspiration appears to be highly dependent on the angular movements of the T7-T10 segment.

Accuracy of t-EMG stimulation of the middle pedicle track to prevent radiculopathies as a result of misplaced lumbar screws.

OBJECTIVE: To describe the accuracy of middle pedicle track stimulation for the detection of pedicle breaches causing misplaced lumbar screws and subsequent neurological symptoms. PATIENTS AND METHODS: In a comparative observational study with two cohorts, 1440 lumbar pedicle screws were implanted using the freehand technique in 242 patients undergoing surgery for spinal deformities. In the first two-year period (2011-2012), the accuracy of screw placement (802 screws) was assessed by conventional intraoperative palpation of the pedicle track, t-EMG screw stimulation, and fluoroscopic monitoring. In the second period (2012-2013), the middle aspect of the lumbar pedicle tracks was systematically stimulated with a probe (638 screws). When thresholds in the middle track showed <9 mA, potential neurological risk was considered, and therefore, new pedicle tracks were performed. RESULTS: Six patients (4.4 %) in the first period presented postoperative radicular pain and a normal intraoperative screw t-EMG threshold. CT scans showed seven screws (0.9 %) with >2-mm medial-caudal invasion of the foramen. Before screw removal, t-EMG thresholds of these screws were again normal (≥10 mA). After removal of the screws. t-EMG of the middle part of the pedicle track showed thresholds below 9 mA (mean 5.2 mA). In the second period, the pedicle tracks were systematically stimulated. Low t-EMG thresholds (<9 mA) were found in 11 tracks (1.7 %) and were therefore reworked before screw placement. CT scans in these 10 patients showed that all of the 11 screws were correctly repositioned. CONCLUSIONS: This study shows that caudal or medial pedicle cortical breaches can be detected effectively by stimulating the middle part of the pedicle track. This technique is strongly recommended to prevent postoperative lumbar radiculopathies due to screw malposition.

Adiposity-Age Distribution and Nutritional Status in Girls With Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Cross-sectional comparative study. OBJECTIVES: To assess the adiposity-age distribution in girls with adolescent idiopathic scoliosis (AIS) and to define the prevalence of underweight, overweight, and obesity in these patients as compared with healthy controls. SUMMARY OF BACKGROUND DATA: The current literature focusing the nutritional status of individuals with AIS does not provide data on the prevalence of overweight in these patients. METHODS: The sample consisted of 112 adolescent girls with idiopathic scoliosis and 231 healthy age-matched girls from the same geographic region. Three different validated body mass index (BMI) cutoffs for adolescents were used to define the nutritional status. Adiposity was labeled according to Adiposity & Fat Distribution for Adolescents (AFAD-A) criteria. RESULTS: There were significant differences in BMI and fat percentage according to age (p < .005) in both AIS patients and healthy controls. The overall prevalence of underweight was similar in both groups (scoliotic girls, 4.5%; controls, 4.8%). Obesity was more prevalent in AIS patients than in healthy controls. The World Health Organization-2007 and the Centers for Disease Control and Prevention cutoffs detected similar percentages of AIS girls with obesity (10.7%) and healthy controls (5.4%). The International Obesity Taskforce detected a 6.3% of AIS girls with obesity and only 3.0% in controls. Fat-age distribution gradually decreases from 11-13 to 16-17 years in AIS patients (p < .05). The overall prevalence of adolescents with fat overload (body fat index [BFI] >7.6) was similar in both groups (AIS, 0.9%; controls, 0.8%). CONCLUSIONS: The proportion of adolescents with obesity was twofold higher among AIS girls than in age-matched healthy controls. However, in AIS girls, the BFI differed from that shown by healthy peers, being lower along the middle adolescence period (13-15 years). AIS girls showed an important increase in underweight at late adolescence (16-17 years). LEVEL OF EVIDENCE: Level III, diagnostic.

Prevention of recurrent urinary tract infections: bridging the gap between clinical practice and guidelines in Latin America.

The branches of the immune system work in concert to defend against pathogens and prevent tissue damage due to excessive inflammation. Uropathogens in general, and uropathogenic Escherichia coli (UPEC) in particular, have evolved a diverse range of virulence mechanisms to avoid detection and destruction by the mucosal immune system of the urinary tract. Research towards a vaccine active against UPEC continues but has yet to be successful. Orally administered immunomodulatory bacterial lysates both stimulate and modulate the immune response in the urinary tract via the integrated mucosal immune system. The 2018 European Association of Urology (EAU) guidelines on treating acute uncomplicated cystitis recommend aiming for rapid resolution of symptoms, reduction of morbidity, and prophylaxis against reinfection. Recommended short-term antibiotic therapy has the advantage of good compliance, low cost, few adverse events, and low impact on bacterial flora. Antibiotic treatment of asymptomatic bacteriuria is only indicated during pregnancy and before invasive interventions. For recurrent infection, prophylaxis using behavioral modification and counseling should be employed first, then nonantibiotic prophylaxis, and, finally, low-dose continuous or postcoital antibiotic prophylaxis. The 2018 EAU guidelines give a strong recommendation for the oral bacterial lysate immunomodulator OM-89. All other nonantibiotic prophylactic strategies require more data, except for topical estrogen for postmenopausal women. For last-resort antibiotic prophylaxis, nitrofurantoin or fosfomycin trometamol are recommended. Guidelines for Latin America are currently being drafted, taking into account the unique ethnicity, availability of medicines, prevalence of antibiotic resistance, and healthcare practices found throughout the region.

Severe hyperkyphosis reduces the aerobic capacity and maximal exercise tolerance in patients with Scheuermann disease.

BACKGROUND CONTEXT: The evaluation of ventilatory functional restrictions during a maximal exercise tolerance test in patients with Scheuermann disease has never been described. PURPOSE: This study evaluated the respiratory functional capacity of patients with Scheuermann disease compared to healthy adolescents matched in age. STUDY DESIGN/SETTING: Prospective comparative study. PATIENTS SAMPLE: Forty-one consecutive adolescents with Scheuermann hyperkyphosis (SK) and 20 healthy controls matched in age were included in the study. OUTCOME MEASURES: Basal spirometry and dynamic ventilatory parameters were measured during a maximal cardiopulmonary exercise tolerance test. Heart rate, oxygen saturation (SatO2), maximum oxygen uptake (VO2 max), quotient between ventilation and volume of exhaled carbon dioxide (VE/CO2), respiratory exchange rate (RER), ventilatory capacity at maximal exercise (VEmax), and test duration were recorded at initium and at maximal exercise. METHODS: The exercise tolerance test (ETT) was completed to exhaustion using a standard Bruce protocol on a ramp treadmill. Comparisons of quantitative variables between SK and control group were analyzed by statistical nonparametric test. The correlations between the magnitude of the thoracic kyphosis and both the VO2 max/kg and VEmax of the SK group were also analyzed. No funds were required. The authors have no conflicts of interests. RESULTS: Patients with SK started the test with a higher heart rate (p<.01) and reached exhaustion with a lower heart rate (p<.05) than healthy controls. At maximal exercise, the SatO2 was declined in Scheuermann patients compared to healthy subjects (p<.05). The maximal aerobic power (VO2max) was greater in healthy controls than in hyperkyphotic patients (50.0±6.7 vs. 43.4±11.3 mL/kg/min; p<.05). There was an inverse correlation between the increase in the magnitude of thoracic kyphosis and the deterioration of the maximal aerobic power. VO2max and VEmax were severely deteriorated in patients with more than 75° kyphosis. Patients with >75° thoracic kyphosis also showed an impairment in their cardiovascular efficiency as measured by the heart rate/VO2 quotient. The limited tolerance to the exercise in SK patients was reflected by a shorter duration of the exercise test and a lower energy cost measured in METS (metabolic equivalents) as compared to healthy controls. CONCLUSIONS: Patients with severe hyperkyphosis (>75°) show significant respiratory inefficiency together with a lower ventilation capacity and lower VO2max. There is an inverse correlation between the increase in the magnitude of thoracic kyphosis and the deterioration of the maximal aerobic power.

Vertebrectomía total y acortamiento vertebral en el manejo de luxación vertebral T12-L1: manejo con medios subóptimos / Total vertebrectomy and spine shortening for the treatment of T12-L1 spine dislocation: Management with suboptimal resources

La vertebrectomía total y el acortamiento vertebral se ha descrito como el tratamiento en el manejo de luxaciones traumáticas vertebrales, tanto en fase aguda como crónica. Presentamos un caso excepcional de una fractura luxación vertebral T12-L1 de 5 semanas de evolución en una mujer de 25 años con paraplejía completa a raíz del traumatismo en Ciudad de León, Nicaragua. Debido al tiempo de evolución de la luxación, realizamos una vertebrectomía completa de L1 para poder reducir la charnela dorsolumbar. Como único material de osteosíntesis disponíamos de 8 tornillos y 2 placas de Steffee, por lo que se implantaron tornillos pediculares en T11, T12, L2 y L3 en el lado derecho y T11, T12, L3 y L4 en el lado izquierdo, y se realizó la reducción de la columna de modo manual. Se colocaron las placas de Steffee y añadimos alambres sublaminares en un intento de reforzar la osteosíntesis. Quince meses después de la cirugía, no ha existido mejoría neurológica

Total vertebrectomy with spine shortening has been reported for the treatment of difficult cases of traumatic spine dislocation, both in acute and chronic phase. We report an exceptional case of a five-week-old T12-L1 spine dislocation in a 25-year-old female with complete paraplegia as a result of trauma in Ciudad de León (Nicaragua). In view of the time since the dislocation, we performed a complete L1 vertebrectomy in order to reduce the dorsolumbar hinge. For osteosynthesis material we had only eight screws and two Steffee plates. We therefore introduced pedicle screws at levels T11, T12, L2 and L3 on the right side and T11, T12, L3 and L4 on the left, and performed manual reduction of the spine. Steffee plates were placed and we added sublaminar wires to reinforce the osteosynthesis. Fifteen months after surgery, there has been no neurological improvement

Analysis of the conflicts of interest disclosed by the program reviewers of the scoliosis research society (SRS) congresses, 2010-2014.

BACKGROUND: Conflicts of interest (COI) between industry and surgeons frequently introduce biases into surgical research. The abstracts submitted for presentation in scientific congresses are usually vetted for any indication of commercial bias. Members of review program committees regularly have recognized qualifications, and therefore certain COI are unavoidable. This study aims to determine the prevalence and magnitude of possible COI among those responsible for the selection of presentations at two important international conferences on spine surgery during a five-year period. METHODOLOGY: COI declarations by those responsible for the final programs of the annual SRS (Scoliosis Research Society) and IMAST (International Meeting of Advanced Spine Technologies) conferences from 2010 to 2014 were collected and analyzed from data published by the corresponding scientific programs. The SRS's disclosure index did not contain financial amounts; therefore, this aspect could not be analyzed. RESULTS: Five scientific committees and 117 members (76 individuals) were studied. Of these 76, 41 (53.9%) participated in more than one conflict of interest (>1 COI). Scientific committee members were from 11 countries across 4 continents, but most were from the Unites States (76.9%). Of the 117 program reviewers, 65.8% declared >1 COI and 34.2% reported no COI. The 77 program reviewers who disclosed a potential COI declared a total of 273 COI (mean = 3.54 COI/member). Overall, 36.0%, 26.1%, 10.7%, and 10.7% of the COI corresponded to consultancies, research funds, bureau participation, and advisory board panel participation, respectively. Stockholder reimbursement corresponded to 8.8% of the disclosed COI, and financial or material support were mentioned in 7.4% of COI. Among the COI disclosures, 55 companies were mentioned, and 5 of the top 10 companies involved in spinal device markets were responsible for 65.2% of the COI. CONCLUSIONS: More than two thirds of the members of the SRS and IMAST scientific committees reported COI. Consultancies and research grants account for two thirds of these. Most of the grants and major COI are related to the five companies leading the spinal implant market.

Total vertebrectomy and spine shortening for the treatment of T12-L1 spine dislocation: Management with suboptimal resources. / Vertebrectomía total y acortamiento vertebral en el manejo de luxación vertebral T12-L1: manejo con medios subóptimos.

Total vertebrectomy with spine shortening has been reported for the treatment of difficult cases of traumatic spine dislocation, both in acute and chronic phase. We report an exceptional case of a five-week-old T12-L1 spine dislocation in a 25-year-old female with complete paraplegia as a result of trauma in Ciudad de León (Nicaragua). In view of the time since the dislocation, we performed a complete L1 vertebrectomy in order to reduce the dorsolumbar hinge. For osteosynthesis material we had only eight screws and two Steffee plates. We therefore introduced pedicle screws at levels T11, T12, L2 and L3 on the right side and T11, T12, L3 and L4 on the left, and performed manual reduction of the spine. Steffee plates were placed and we added sublaminar wires to reinforce the osteosynthesis. Fifteen months after surgery, there has been no neurological improvement.

Novel porcine experimental model of severe progressive thoracic scoliosis with compensatory curves induced by interpedicular bent rigid temporary tethering.

Using flexible tethering techniques, porcine models of experimental scoliosis have shown scoliotic curves with vertebral wedging but very limited axial rotation. The aim of this experimental work was to induce a severe progressive scoliosis in a growing porcine model for research purposes. A unilateral spinal bent rigid tether was anchored to two ipsilateral pedicle screws in eight pigs. The spinal tether was removed after 8 weeks. Ten weeks later, the animals were sacrificed. Conventional radiographs and 3D CT-scans were taken to evaluate changes in the alignment of the thoracic spine. After the first 8 weeks of rigid tethering, all animals developed scoliotic curves (mean Cobb angle: 24.3°). Once the interpedicular tether was removed, the scoliotic curves progressed in all animals during 10 weeks reaching a mean Cobb angle of 49.9°. The sagittal alignment of the thoracic spine showed loss of physiologic kyphosis (Mean: -18.3°). Axial rotation ranged from 10° to 49° (Mean 25.7°). Release of the spinal tether results in progression of the deformity with the development of proximal and distal compensatory curves. In conclusion, temporary interpedicular tethering at the thoracic spine induces severe scoliotic curves in pigs, with significant wedging and rotation of the vertebral bodies, and true compensatory curves. CLINICAL RELEVANCE: The tether release model will be used to evaluate corrective non-fusion technologies in future investigations. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:174-182, 2018.

Evolución radiológica a largo plazo de las fracturas inestables toracolumbares sin clínica neurológica / Long term radiological outcomes of unstable thoraco-lumbar fractures without neurological deficit

Objetivo: Analizar la evolución radiológica de las fracturas inestables toracolumbares a largo plazo. Material y métodos: Serie retrospectiva de 100 casos con fracturas inestables toracolumbares sin clínica neurológica tratadas con artrodesis posterolateral e instrumentación corta en el caso de fracturas por compresión y flexión-distracción e instrumentación larga para las fracturas-luxaciones o a más de un nivel entre el 2000 y 2010 en 3 hospitales diferentes. Se midieron 6 parámetros radiológicos anualmente durante un período de 4 años: ángulo fractuario, deformidad cifótica, índice sagital, porcentaje de compresión, grado de desplazamiento y ángulo de deformación. Resultados: Se incluyeron un total de 100 pacientes de 36,4 años de media con un período de seguimiento medio de 7,2 años. El ángulo fractuario pasó de 11,6° a 14,5° (incremento del 25%), la deformidad cifótica de 14,5° a 16,7° (incremento del 15,17%), el índice sagital de 8,7 a 10,8 (incremento del 24,13%), el porcentaje de compresión del 31,8% al 36,5% (incremento del 6,88%), el grado de desplazamiento de 2,8mm a 4,6mm (incremento del 14,77%) y el ángulo de deformación de 19,7° a 21,4° (incremento del 8,62%). Discusión: Todos los parámetros radiológicos estudiados perdieron corrección a lo largo de los 48 meses de seguimiento, siendo el ángulo fractuario el más marcado. Sin embargo, la mayor parte de la pérdida de corrección ocurre en el primer año postoperatorio, estabilizándose los parámetros posteriormente hasta los 4 años de seguimiento. Recomendamos la medición de todos los parámetros previos de rutina para el seguimiento de las fracturas inestables toracolumbares

Objective: To analyse the radiological outcomes in the long term of unstable thoraco-lumbar fractures. Material and methods: Retrospective review of 100 patients with unstable thoracolumbar fractures treated with posterolateral fusion and short screw fixation for compression and flexion-distraction type fractures, and long segment posterior fixation for fractures-dislocations or more than one vertebra fractured, between 2000 and 2010 at three different hospital centers. Six radiological parameters were measured annually during a 4-year period: Fracture angle, kyphotic deformity, sagittal index, percentage of compression, degree of displacement and deformation angle. Results: A total of 100 patients were included with a median age of 36,4 years and a median follow-up period of 7.2 years. Fracture angle rose from 11,6° to 14,5° (increase of 25%), kyphotic deformity from 14,5° to 16,7° (increase of 15,17%), sagittal index from 8,7 to 10,8 (increase of 24,13%), percentage of compression from 31,8% to 36,5% (increase of 6,88%), degree of displacement from 2,8mm to 4,6mm (increase of 14,77%) and deformation angle from 19.7° to 21.4° (increase of 8,62%). Discussion: All the radiological parameters studied lost correction throughout the 48 months of follow-up, being the fracture angle the most affected one. Nevertheless, the greatest loss of correction occurs in the first postoperative year, stabilizing the parameters afterwards over the 4 years of follow up. We routinely recommend the measurement of all previous parameters for the follow up of unstable thoracolumbar fractures

[Long term radiological outcomes of unstable thoraco-lumbar fractures without neurological deficit]. / Evolución radiológica a largo plazo de las fracturas inestables toracolumbares sin clínica neurológica.

OBJECTIVE: To analyse the radiological outcomes in the long term of unstable thoraco-lumbar fractures. MATERIAL AND METHODS: Retrospective review of 100 patients with unstable thoracolumbar fractures treated with posterolateral fusion and short screw fixation for compression and flexion-distraction type fractures, and long segment posterior fixation for fractures-dislocations or more than one vertebra fractured, between 2000 and 2010 at three different hospital centers. Six radiological parameters were measured annually during a 4-year period: Fracture angle, kyphotic deformity, sagittal index, percentage of compression, degree of displacement and deformation angle. RESULTS: A total of 100 patients were included with a median age of 36,4 years and a median follow-up period of 7.2 years. Fracture angle rose from 11,6° to 14,5° (increase of 25%), kyphotic deformity from 14,5° to 16,7° (increase of 15,17%), sagittal index from 8,7 to 10,8 (increase of 24,13%), percentage of compression from 31,8% to 36,5% (increase of 6,88%), degree of displacement from 2,8mm to 4,6mm (increase of 14,77%) and deformation angle from 19.7° to 21.4° (increase of 8,62%). DISCUSSION: All the radiological parameters studied lost correction throughout the 48 months of follow-up, being the fracture angle the most affected one. Nevertheless, the greatest loss of correction occurs in the first postoperative year, stabilizing the parameters afterwards over the 4 years of follow up. We routinely recommend the measurement of all previous parameters for the follow up of unstable thoracolumbar fractures.

Cardiorespiratory Function Does Not Improve 2 Years After Posterior Surgical Correction of Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A prospective evaluation of cardiorespiratory function following spinal fusion in adolescent idiopathic scoliosis (AIS). OBJECTIVE: To evaluate the cardiopulmonary function during exercise in patients with severe AIS, before and 2 years after undergoing a posterior spinal fusion. SUMMARY OF BACKGROUND DATA: After surgical correction of scoliosis, a greater cardiorespiratory adaptation to exercise would be expected from correction of the rib cage associated with the spine deformity. However, there is no clear evidence regarding whether tolerance to maximum exercise improves in the medium term after surgery in patients with severe curves. METHODS: We include patients with AIS proposed for posterior surgical correction aging between 12 and 17 years. Every patient had a Cobb angle >45° and a Lenke type 1A scoliosis. Cardiac and respiratory functional measures, such as heart rate and blood pressure, maximum oxygen consumption (VO2max), eliminated volume of carbon dioxide (VCO2), quotient between ventilation and volume of exhaled carbon dioxide (VE/CO2), respiratory exchange rate, ventilatory capacity at maximal exercise (VEmax), were recorded before and 2 years after surgery. RESULTS: Twenty patients were included in our study, 15 girls and 5 boys, with an average age of 13 years. The main scoliotic curve was corrected in the coronal plane in an average of 71.9%. The maximal aerobic power expressed by body weight normalized VO2max was found preoperatively to have an average of 30.9 ±â€Š6.2 mL/kg/minute, indicating a poor aerobic capacity, which did not improve at final follow-up, decreasing to a mean value of 29.3 ±â€Š5.7 but without statistical significance. However, the percentages of curve correction showed a statistically significant correlation with VO2max (r = 0.534; P < 0.05). CONCLUSION: Patients with severe adolescent idiopathic scoliosis Lenke type 1A showed limited cardiorespiratory tolerance to maximum exercise that did not improve 2 years after surgery. LEVEL OF EVIDENCE: 3.

Neurophysiological monitoring during acute and progressive experimentally induced compression injury of the spinal cord in pigs.

PURPOSE: To evaluate the degree of acute or progressive lateral compression needed to cause neurologic injury to the spinal cord assessed by electrophysiological monitoring. METHODS: In five domestic pigs, the spinal cord was exposed and compressed between T8-T9 roots using a precise compression device. Two sticks placed on both sides of the spinal cord were sequentially brought together (0.5 mm every 2 min), causing progressive spinal cord compression. Acute compression was reproduced by a 2.5-mm displacement of the sticks. Cord-to-cord evoked potentials were obtained with two epidural catheters. RESULTS: Increasing latency and decreasing amplitude of the evoked potentials were observed after a mean progressive displacement of the sticks of 3.2 ± 0.9 mm, disappearing after a mean displacement of 4.6 ± 1.2 mm. The potential returned after compression removal (16.8 ± 3.2 min). The potentials disappeared immediately after an acute compression of 2.5 ± 0.3 mm, without any sign of recovering after 30 min. CONCLUSIONS: The experimental model replicates the mechanism of a spinal cord injury caused by medially displaced screws into the spinal canal. The spinal cord had more ability for adaptation to progressive and slow compression than to acute mechanisms.