Does the interfacing angle between pedicle screws and support rods affect clinical outcomes after posterior thoracolumbar fusion? A retrospective clinical study.

BACKGROUND CONTEXT: Proper alignment and tightening of the pedicle screw/rod assembly after instrumented posterior fusion of the lower spine is known to be crucial in order to achieve satisfactory clinical results. Such interfacing angle mismatches indicate stress overloading of the implant system. PURPOSE: The objective of this study is to investigate the incidence of postoperative screw/rod interfacing angle mismatch and to analyze the impact of mismatches on clinical outcome in terms of (1) revision surgery, (2) adjacent segment degeneration (ASD), and (3) pain. STUDY DESIGN: This is a monocentric retrospective observational study. PATIENT SAMPLE: Patients underwent fusion surgery with pedicle screw/rod systems for predominantly degenerative pathologies. OUTCOME MEASURES: Pedicle screw/rod interfacing angle mismatch (mismatch is the angular deviation from 90° formed by the rod axis and the pedicle screw head axis as an indicator for missing form-fit) revision rate, ASD at the immediately adjacent cranial segment and VAS pain. METHODS: Revision refers to subsequent procedures in which all or part of the original implant configuration is changed or removed. Radiographic parameters are evaluated using a/p and lateral radiographs at final follow-up. The interfacing angle mismatch between pedicle screw and rod is measured as the angle between two parallel lines on either side of each pedicle screw head and a line laterally along the associated rod. Multiple comparisons are counteracted by Bonferroni correction, adjusted significance level is at *p<.01. RESULTS: Pedicle screw and rod interfacing angle mismatch was found in 171/406 (42.1%) of patients undergoing fusion surgery, affecting 613/3016 (20.3%) screws. The overall revision incidence was 11.8% (48/406), and a new ASD occurred in 12.1% of all patients (49/406) with an average follow-up of 5 years. Mean VAS pain score at final follow-up was 2.0. Comparison of the two groups with and without mismatches revealed statistically significantly higher (1) numbers of revision procedures performed (26.9% vs 0.9%), (2) numbers of new ASD developed (27.5% vs 3.8%), and (3) higher VAS pain scores (2.8/10 vs 1.4/10) for cases with mismatch. When comparing patients who underwent intraoperative correction and/or reduction with those who did not, statistically significant more screw mismatches (63.4% vs 39.7%) and revision surgeries (29.3% vs 9.9%) were noted in patients who had these forceful maneuvers. CONCLUSIONS: Pedicle screw/rod interfacing angle mismatch is a frequent occurrence after fusion surgery. Mismatches indicate that the construct was assembled under mechanical stress. All preventable mechanical stresses, for example, unintentional uncontrolled forces on the instrumentation, should be avoided as much as possible, as they can negatively influence the clinical outcome.

Influence of Stress and Emotions in the Learning Process: The Example of COVID-19 on University Students: A Narrative Review.

Emotional instability and stress are the main disturbances that condition the learning process, affecting both teachers and students. The main objective of this review is to analyze the influence of stress and emotions (as part of stress) on the learning environment. Stress is a physiological mechanism that the organism develops to adapt and survive external and internal challenges. In this context, stress tends to be seen as a negative condition in the learning process when it is chronic. Extreme stress situations, such as the COVID-19 pandemic, can generate anxiety and frustration in students. However, other studies indicate that controlled stress can positively enhance the learning process. On the other hand, the quality and intensity of emotions resulting from stress can influence as well the learning process. Positive emotions are healthy and can promote optimal learning. Emotions lead to sentimental, cognitive, behavioral, and physiological changes, which will have a strong influence on intellectual performance. The activation of coping strategies constitutes a key mechanism for dealing positively with problems and challenges, generating positive emotions essential for the self-regulation of learning. In conclusion, correct management of emotions in stressful situations could promote effective learning through enhanced attention and capacity to solve problems.

Efficacy of a 4-Antigen Staphylococcus aureus Vaccine in Spinal Surgery: The STaphylococcus aureus suRgical Inpatient Vaccine Efficacy (STRIVE) Randomized Clinical Trial.

BACKGROUND: Staphylococcus aureus is a global pathogen that is frequently responsible for healthcare-associated infections, including surgical site infections (SSIs). Current infection prevention and control approaches may be limited, with S. aureus antibiotic resistance remaining problematic. Thus, a vaccine to prevent or reduce S. aureus infection is critically needed. We evaluated the efficacy and safety of an investigational 4-antigen S. aureus vaccine (SA4Ag) in adults undergoing elective open posterior spinal fusion procedures with multilevel instrumentation. METHODS: In this multicenter, site-level, randomized, double-blind trial, patients aged 18-85 years received a single dose of SA4Ag or placebo 10-60 days before surgery. SA4Ag efficacy in preventing postoperative S. aureus bloodstream infection and/or deep incisional or organ/space SSIs was the primary end point. Safety evaluations included local reactions, systemic events, and adverse events (AEs). Immunogenicity and colonization were assessed. RESULTS: Study enrollment was halted when a prespecified interim efficacy analysis met predefined futility criteria. SA4Ag showed no efficacy (0.0%) in preventing postoperative S. aureus infection (14 cases in each group through postoperative day 90), despite inducing robust functional immune responses to each antigen compared with placebo. Colonization rates across groups were similar through postoperative day 180. Local reactions and systemic events were mostly mild or moderate in severity, with AEs reported at similar frequencies across groups. CONCLUSIONS: In patients undergoing elective spinal fusion surgical procedures, SA4Ag was safe and well tolerated but, despite eliciting substantial antibody responses that blocked key S. aureus virulence mechanisms, was not efficacious in preventing S. aureus infection. Clinical Trials Registration. NCT02388165.

AO/OTA type C3 distal humeral fractures in patients aged 75 years and older: Is ORIF with double precontoured anatomical locking plates a reliable treatment?

INTRODUCTION: The incidence of osteoporotic distal humeral fractures (DHF) is on the rise. Their operative management is demanding. Fixation with non-locking reconstruction plates was associate with a high number of complications. Elbow arthroplasty (total or hemi) has been proposed as an alternative treatment, in spite of lifetime activity restrictions, and risk of complications, unknown implant survival and problematic revision surgery. Precontoured anatomical locking plates have increased the strength of the fixation in complex fractures. HYPOTHESIS: double plating ORIF with precontoured anatomical locking plates is a safe and reliable treatment option for the management of AO/OTA type C3 DHF in patients aged 75 and older. PATIENTS AND METHODS: A retrospective case series study of patients aged 75 years old and older with an AO/OTA type C3 DHF treated with ORIF with double precontoured anatomical locking plates between 2007 and 2021. Pathologic fractures were excluded. Patients' demographic, surgical, clinical, and radiological data were reviewed. RESULTS: A total of 27 women and 3 men, mean age of 80.1 years (range 75-93 years), were included. Mean Charlson index was 5 (range 3-8). Out of 30 patients, 19 had already died. Mean survival time after the surgical treatment was 72.3 months. Mean Mayo elbow performance score was 88.9 (range 60-100); 23 patients scored excellent or good. All fractures healed with no cases of delay union or non-union, hardware failure or loss of reduction. No patient needed a revision surgery to arthroplasty. The total number of complications was 12 (40%), mainly ulnar neuropathy (5) and cerclage removal (4). CONCLUSION: ORIF with double pre-contoured locking plates may be a safe and reliable treatment for type C3 DHF in patients aged 75 years and older, with a good functional outcome. Complications are expected but not related to loss of reduction, fixation failure or revision to elbow arthroplasty.

Plantar Fasciitis in Soccer Players-A Systemic Review.

Soccer is one of the most popular sports in the world. Players often suffer a variety of injuries, the most common being injuries to muscles and tendons. It is striking that with soccer, being the most practiced sport, and considering that most injuries occur in the lower extremities, plantar fasciitis (PF) is not one of the most frequent injuries (at least in terms of clinical data collected). The purpose of this review was to provide a comprehensive update of the topic "plantar fasciitis" focusing on soccer players. The review was conducted in accordance with the PRISMA (Preferred Reportiog ltems for Systmiatic reviews and Meta-Analyses) statement. PubMed, Cochrane Library and Scopus were researched. PICO (Patient, Population or Problem; Intervention; Comparison; and Outcome) components were identified. The keywords used were "plantar fasciitis", "plantar fasciitis and sport", "plantar fasciitis risk factors", "plantar fasciitis soccer" and "plantar fasciitis football players". With respect to the objective proposed for the research, we found eight specific articles focused on soccer. Of these, five were general reviews discussing the different methods of treatment of this pathology, and we have only found three studies that focused on PF in soccer, with two of them referring to a clinical case whereby the report and discussion only dealt with the specific treatment followed by the soccer player. After reviewing the manuscripts included in this work, we were surprised that there is no data in which the Silfverskiöld test was performed, as this test explores the passive mobility of the ankle and the degree of dorsiflexion in the supine position. We concluded that soccer players suffer pain in the sole of the foot compatible with plantar fasciitis; however, as indicated by Suzue et al., it is often not diagnosed because the athlete does not consider performing the clinical examinations necessary for its diagnosis. The shortage of reported publications in soccer may mask other PF-associated injuries.

Effects and Causes of Detraining in Athletes Due to COVID-19: A Review.

Several aspects of systemic alterations caused by the SARS-CoV-2 virus and the resultant COVID-19 disease have been currently explored in the general population. However, very little is known about these particular aspects in sportsmen and sportswomen. We believe that the most important element to take into account is the neuromuscular aspect, due to the implications that this system entails in motion execution and coordination. In this context, deficient neuromuscular control when performing dynamic actions can be an important risk factor for injury. Therefore, data in this review refer mainly to problems derived in the short term from athletes who have suffered this pathology, taking into account that COVID-19 is a very new disease and the presented data are still not conclusive. The review addresses two key aspects: performance alteration and the return to regular professional physical activity. COVID-19 causes metabolic-respiratory, muscular, cardiac, and neurological alterations that are accompanied by a situation of stress. All of these have a clear influence on performance but at the same time in the strategy of returning to optimal conditions to train and compete again after infection. From the clinical evidence, the resumption of physical training and sports activity should be carried out progressively, both in terms of time and intensity.

Biological Approach in the Treatment of External Popliteal Sciatic Nerve (Epsn) Neurological Injury: Review.

The external popliteal sciatic nerve (EPSN) is the nerve of the lower extremity most frequently affected by compressive etiology. Its superficial and sinuous anatomical course is closely related to other rigid anatomical structures and has an important dynamic neural component. Therefore, this circumstance means that this nerve is exposed to multiple causes of compressive etiology. Despite this fact, there are few publications with extensive case studies dealing with treatment. In this review, we propose to carry out a narrative review of the neuropathy of the EPSN, including an anatomical reminder, its clinical presentation and diagnosis, as well as its surgical and biological approach. The most novel aspect we propose is the review of the possible role of biological factors in the reversal of this situation.

l-Arginine and Beetroot Extract Supplementation in the Prevention of Sarcopenia.

Aging is associated with a significant decline in neuromuscular function, leading to a reduction in muscle mass and strength. The aim of the present report was to evaluate the effect of supplementation with nitric oxide precursors (l-arginine and beetroot extract) in muscular function during a training period of 6 weeks in elderly men and women. The study (double-blind, placebo-controlled) involved 66 subjects randomly divided into three groups: placebo, arginine-supplemented and beetroot extract-supplemented. At the end of this period, no changes in anthropometric parameters were observed. Regarding other circulating parameters, urea levels were significantly (p < 0.05) lower in women of the beetroot-supplemented group (31.6 ± 5.9 mg/dL) compared to placebo (41.3 ± 8.5 mg/dL) after 6 weeks of training. In addition, the circulating creatine kinase activity, as an index of muscle functionality, was significantly (p < 0.05) higher in women of the arginine- (214.1 ± 162.2 mIU/L) compared to the beetroot-supplemented group (84.4 ± 36.8 mIU/L) at the end of intervention. No significant effects were noticed with l-arginine or beetroot extract supplementation regarding strength, endurance and SPPB index. Only beetroot extract supplementation improved physical fitness significantly (p < 0.05) in the sprint exercise in men after 6 weeks (2.33 ± 0.59 s) compared to the baseline (2.72 ± 0.41 s). In conclusion, beetroot seems to be more efficient during short-term training while supplementing, preserving muscle functionality in women (decreased levels of circulating creatine kinase) and with modest effects in men.

ß-Glucans Could Be Adjuvants for SARS-CoV-2 Virus Vaccines (COVID-19).

Waiting for an effective treatment against the SARS-CoV-2 virus (the cause of COVID-19), the current alternatives include prevention and the use of vaccines. At the moment, vaccination is the most effective strategy in the fight against pandemic. Vaccines can be administered with different natural biological products (adjuvants) with immunomodulating properties. Adjuvants can be taken orally, complementing vaccine action. Adjuvant compounds could play a key role in alleviating the symptoms of the disease, as well as in enhancing vaccine action. Adjuvants also contribute to an effective immune response and can enhance the protective effect of vaccines in immunocompromised individuals such as the elderly. Adjuvants must not produce adverse effects, toxicity, or any other symptoms that could alter immune system function. Vaccine adjuvants are substances of wide varying chemical structure that are used to boost the immune response against a simultaneously administered antigen. Glucans could work as adjuvants due to their immunomodulatory biological activity. In this respect, ß-(1,3)-(1,6) glucans are considered the most effective and safe according to the list issued by the European Commission. Only glucans with a ß-(1,3) bond linked to a ß-(1,6) are considered modulators of certain biological responses. The aim of this review is to present the possible effects of ß-glucans as adjuvants in the efficacy of vaccines against SARS-CoV-2 virus.

The Immunomodulatory Function of Vitamin D, with Particular Reference to SARS-CoV-2.

Vaccines are the only way to reduce the morbidity associated to SARS-CoV-2 infection. The appearance of new mutations urges us to increase the effectiveness of vaccines as a complementary alternative. In this context, the use of adjuvant strategies has improved the effectiveness of different vaccines against virus infections such as dengue, influenza, and common cold. Recent reports on patients infected by COVID-19 reveal that low levels of circulating vitamin D correlate with a severe respiratory insufficiency. The immunomodulatory activity of this micronutrient attenuates the synthesis of pro-inflammatory cytokines and at the same time, increases antibody production. Therefore, the present review proposes the use of vitamin D as adjuvant micronutrient to increase the efficacy of vaccines against SARS-CoV-2 infection.

Effects of Vitamin D in Post-Exercise Muscle Recovery. A Systematic Review and Meta-Analysis.

Vitamin D is a key micronutrient modulating function and health in skeletal muscle. Therefore, we sought to systematically review the role of vitamin D in muscle recovery. A search in different databases (PubMed/MEDLINE, WOS, Google Scholar, and Scopus) was carried out following PRISMA® and PICOS. The search period was from inception to April 2020. Changes in post-exercise muscle damage were quantified comparing experimental group vs. placebo in each study by using number of participants, standardized mean difference (SMD), and standard error of the SMD. Hedges's g was used to calculate the SMDs for each study group and biased by the inverse of variance that allows calculating an overall effect and the 95% confidence interval (CI). The net vitamin D supplementation effect was calculated by subtracting the placebo SMD from SMD of the experimental group. The DerSimonian and Laird method was used as a random effect model, taking into account that the effect of vitamin D on muscular damage may vary according to the dose administered and additional moderators. Six studies were selected. In conclusion, regarding circulating levels of muscle biomarkers and additional limitations of the studies, it cannot be concluded that vitamin D supplementation exerts an effect in post-exercise muscle recovery. Likely, the anti-inflammatory action of vitamin D is quicker than the recovery of tissue structure and function. This aspect is pending verification in future research.

Effect of Vitamin D Supplementation on Muscle Status in Old Patients Recovering from COVID-19 Infection.

Background and Objectives: Vitamin D, in addition to its effect on mineral homeostasis, plays a key role in muscle metabolism. Vitamin D supplementation is involved in muscle recovery after damage as a consequence of either pathology or after high-intensity exercise. In this context, the aim of this study was to analyze the effect of vitamin D on muscle fitness in elderly patients in the recovery phase after SARS-CoV-2 (COVID-19) infection. Materials and Methods: This pilot study was conducted at the Soria Norte Health Center. The study consisted of a double-blind trial with two groups of men (placebo and vitamin D-supplemented) (n = 15/group). Treatment with vitamin D (cholecalciferol: 2000 IU/day) and placebo was carried out for 6 weeks. Circulating hematological and biochemical parameters (total protein, glucose, vitamin D, urea, uric acid, aspartate aminotransferase/glutamic-oxaloacetic transaminase, alanine aminotransferase/glutamic-pyruvic transaminase, creatine kinase, lactate dehydrogenase, aldolase, gamma-glutamyl transferase and myoglobin) and the hormones cortisol and testosterone were determined. As for respiratory function tests, FEV1 and respiratory flow were also studied. For physical fitness tests, the "six-minute walk test" (6MWT) was used. Results: After vitamin D supplementation, we observed that serum creatine kinase levels returned to optimal values. This change suggests a protective role of vitamin D against muscle catabolism compared to placebo. In terms of physical test results, we observed only slight non-significant improvements, although patients reported feeling better. Conclusions: Vitamin D supplementation produces decreases in indicators of muscle damage, which may ultimately contribute to improving the health status and quality of life of patients who have suffered from COVID-19, during the recovery process.

Treatment of Thoracolumbar Type A3 Fractures Using a Percutaneous Intravertebral Expandable Titanium Implant: Long-term Follow-up Results of a Pilot Single Center Study.

BACKGROUND: There are controversies about the optimal management of AO subtype A3 burst fractures. The most common surgical treatment consists of posterior fixation with pedicle screw and rod augmentation. Nevertheless, a loss of correction in height restoration and kyphotic reduction has been observed. OBJECTIVES: The aim of this study was to assess long-term outcomes of a minimally invasive technique using a percutaneous intravertebral expandable titanium implant (PIETI). STUDY DESIGN: This prospective, single center, pilot study was carried out on a consecutive case series of 44 patients with acute (< 2 weeks) traumatic thoracolumbar fractures AO type A3. The average follow-up was 5.6 years. SETTING: A single center in Castilla y Leon, SpainMETHODS: Clinical outcomes (pain intensity on visual analog scale [VAS], Oswestry Disability Index [ODI], analgesic consumption) and radiographic outcomes (anterior/mid/posterior vertebral body height, vertebral area, local kyphosis angle, traumatic regional angulation) were analyzed before surgery, at one month after surgery, and at the end of the follow-up period. RESULTS: At one-month postsurgery, significant improvements in VAS score and ODI score were observed. PIETI achieved significant vertebral body height restoration with median height increases of 2.9 mm/4.3 mm/2.3 mm for anterior/middle/posterior parts, respectively. Significant correction of the local kyphotic angle and improvement of the traumatic regional angulation were accomplished. All these improvements were maintained throughout the follow-up period. The only complication reported was a case of cement leakage. LIMITATIONS: In our opinion, the main limitation of the study is the small number of patients. However, the sample is superior to that shown in other papers. CONCLUSIONS: This study showed that using a PIETI in the treatment of fractures type A3 is a safe and effective method that allows marked clinical improvement, as well as anatomical vertebral body restoration. Unlike with other treatments, results were maintained over time, allowing a better long-term clinical and functional improvement. The rate of cement leakage was lower than other reports.

Misaligned spinal rods can induce high internal forces consistent with those observed to cause screw pullout and disc degeneration.

BACKGROUND CONTEXT: Manual contouring of spinal rods is often required intraoperatively for proper alignment of the rods within the pedicle screw heads. Residual misalignments are frequently reduced by using dedicated reduction devices. The forces exerted by these devices, however, are uncontrolled and may lead to excessive reaction forces. As a consequence, screw pullout might be provoked and surrounding tissue may experience unfavorable biomechanical loads. The corresponding loads and induced tissue deformations are however not well identified. Additionally, whether the forced reduction alters the biomechanical behavior of the lumbar spine during physiological movements postoperatively, remains unexplored. PURPOSE: To predict whether the reduction of misaligned posterior instrumentation might result in clinical complications directly after reduction and during a subsequent physiological flexion movement. STUDY DESIGN: Finite element analysis. METHODS: A patient-specific, total lumbar (L1-S1) spine finite element model was available from previous research. The model consists of poro-elastic intervertebral discs with Pfirrmann grade-dependent material parameters, with linear elastic bone tissue with stiffness values related to the local bone density, and with the seven major ligaments per spinal motion segment described as nonlinear materials. Titanium instrumentation was implemented in this model to simulate a L4, L5, and S1 posterolateral fusion. Next, coronal and sagittal misalignments of 6 mm each were introduced between the rod and the screw head at L4. These misalignments were computationally reduced and a physiological flexion movement of 15° was prescribed. Non-instrumented and well-aligned instrumented models were used as control groups. RESULTS: Pulling forces up to 1.0 kN were required to correct the induced misalignments of 6 mm. These forces affected the posture of the total lumbar spine, as motion segments were predicted to rotate up to 3 degrees and rotations propagated proximally to and even affect the L1-2 level. The facet contact pressures in the corrected misaligned models were asymmetrical suggesting non-physiological joint loading in the misaligned models. In addition, the discs and vertebrae experienced abnormally high forces as a result of the correction procedure. These effects were more pronounced after a 15° flexion movement following forced reduction. CONCLUSIONS: The results of this study indicate that the correction of misaligned posterior instrumentation can result in high forces at the screws consistent with those reported to cause screw pullout, and may cause high-tissue strains in adjacent and downstream spinal segments. CLINICAL SIGNIFICANCE: Proper alignment of spinal posterior instrumentation may reduce clinical complications secondary to unfavorable biomechanics.

Influence of HLA Matching on the Efficacy of Allogeneic Mesenchymal Stromal Cell Therapies for Osteoarthritis and Degenerative Disc Disease.

BACKGROUND: The necessity for more effective therapies for chronic osteoarticular diseases has led to the development of treatments based on mesenchymal stem cells (MSCs), the natural precursors of musculoskeletal tissue. Treatments with autologous MSCs yielded excellent results, with nearly 70% improvement of pain and disability in osteoarthritis and degenerative disc disease. Using allogeneic MSCs is logistically more convenient and would widen the pool of eligible patients, but potential immune rejection should be considered. In this context, MSCs are purportedly immune evasive and better tolerated than other cell types. METHODS: We used samples collected during the performance of 2 randomized clinical trials using allogeneic bone marrow MSCs for treatment of osteoarthritis (NCT01586312) and degenerative disc disease (NCT01860417). Serum samples were used to determine anti-HLA antibodies, whereas either blood or MSC samples were used for HLA typing of recipients and donors, respectively. Algofunctional indexes were used as indicators of clinical evolution, and the correlation between the number of donor-host HLA mismatches and the efficacy of treatment was determined. RESULTS: Immune response was weak and transient, with reactivity decaying during the first year. Consistently, better donor-recipient HLA matching did not enhance efficacy. CONCLUSIONS: This lack of reactivity is presumably due to the cooperation of 2 factors, (1) downregulation of the host immune responses by the transplanted MSCs and (2) effective insulation of these cells inside the articular cavity or the intervertebral disc, respectively. Interestingly, better HLA matching did not enhance efficacy. These observations have medical relevance as they support the clinical use of allogeneic cells, at least as a single-dose administration. Multiple-dose applications will require further research to exclude possible sensitization.

Requirements for a Stable Long-Term Result in Surgical Reduction of Vertebral Fragility Fractures.

BACKGROUND: Osteoporotic vertebral fractures are one of the major health problems in the world. Minimally invasive surgical treatment has great advantages compared with conservative treatment in treating these fractures, because it eliminates pain and functional disability. The percutaneous intravertebral expandable titanium device SpineJack (Vexim SA, Balma, France) is beneficial compared with other kyphoplasty devices, showing results that are maintained over time and a reduction in complications. However, controversy exists about the minimum amount of cement that should be used to achieve long-term restoration and which is essential to minimize complications. We reviewed publications studying the maintenance of long-term restoration using this percutaneous expandable titanium device in cadavers. In this study, we show the first long-term work with patients treated with percutaneous expandable titanium device, describing precise indications concerning the minimum amount of cement that should be used. METHODS: Results were evaluated from a clinical study including 178 patient outcomes with long-term follow-up results performed by our team. RESULTS: The mean total quantity of cement injected was 4.4 mL (25% vertebral body filling). The leakage rate was 12.9%, and all of these occurrences were asymptomatic. The mean follow-up time was 77 months (60-96 months). All clinical scales improved significantly after the procedure. A recollapse of the treated vertebra was observed in 3 cases (1.6%), and the adjacent fracture rate was 2.2%. CONCLUSIONS: From the results of our study and review of the literature, cement equivalent to 25% of the vertebral body filling volume, when combined with the titanium expandable device, seems to be sufficient to prevent recollapse in osteoporotic and type A.3 fractures.

Intervertebral Disc Repair by Allogeneic Mesenchymal Bone Marrow Cells: A Randomized Controlled Trial.

BACKGROUND: Degenerative disc disease often causes severe low-back pain, a public health problem with huge economic and life quality impact. Chronic cases often require surgery, which may lead to biomechanical problems and accelerated degeneration of the adjacent segments. Autologous mesenchymal stromal cells (MSC) treatments have shown feasibility, safety and strong indications of clinical efficacy. We present here a randomized, controlled trial using allogeneic MSC, which are logistically more convenient than autologous cells. METHODS: We randomized 24 patients with chronic back pain diagnosed with lumbar disk degeneration and unresponsive to conservative treatments into 2 groups. The test group received allogeneic bone marrow MSCs by intradiscal injection of 25 × 10 cells per segment under local anesthesia. The control group received a sham infiltration of paravertebral musculature with the anesthetic. Clinical outcomes were followed up for 1 year and included evaluation of pain, disability, and quality of life. Disc quality was followed up by magnetic resonance imaging. RESULTS: Feasibility and safety were confirmed and indications of clinical efficacy were identified. MSC-treated patients displayed a quick and significant improvement in algofunctional indices versus the controls. This improvement seemed restricted to a group of responders that included 40% of the cohort. Degeneration, quantified by Pfirrmann grading, improved in the MSC-treated patients and worsened in the controls. CONCLUSIONS: Allogeneic MSC therapy may be a valid alternative for the treatment of degenerative disc disease that is more logistically convenient than the autologous MSC treatment. The intervention is simple, does not require surgery, provides pain relief, and significantly improves disc quality.

Risk-benefit analysis of navigation techniques for vertebral transpedicular instrumentation: a prospective study.

BACKGROUND CONTEXT: Pedicle screws in spinal surgery have allowed greater biomechanical stability and higher fusion rates. However, malposition is very common and may cause neurologic, vascular, and visceral injuries and compromise mechanical stability. PURPOSE: The purpose of this study was to compare the malposition rate between intraoperative computed tomography (CT) scan assisted-navigation and free-hand fluoroscopy-guided techniques for placement of pedicle screw instrumentation. STUDY DESIGN/SETTING: This is a prospective, randomized, observational study. PATIENT SAMPLE: A total of 114 patients were included: 58 in the assisted surgery group and 56 in the free-hand fluoroscopy-guided surgery group. OUTCOME MEASURES: Analysis of screw position was assessed using the Heary classification. Breach severity was defined according to the Gertzbein classification. Radiation doses were evaluated using thermoluminescent dosimeters, and estimates of effective and organ doses were made based on scan technical parameters. METHODS: Consecutive patients with degenerative disease, who underwent surgical procedures using the free-hand, or intraoperative navigation technique for placement of transpedicular instrumentation, were included in the study. RESULTS: Forty-four out of 625 implanted screws were malpositioned: 11 (3.6%) in the navigated surgery group and 33 (10.3%) in the free-hand group (p<.001). Screw position according to the Heary scale was Grade II (4 navigated surgery, 6 fluoroscopy guided), Grade III (3 navigated surgery, 11 fluoroscopy guided), Grade IV (4 navigated surgery, 16 fluoroscopy guided), and Grade V (1 fluoroscopy guided). There was only one symptomatic case in the conventional surgery group. Breach severity was seven Grade A and four Grade B in the navigated surgery group, and eight Grade A, 24 Grade B, and one Grade C in free-hand fluoroscopy-guided surgery group. Radiation received per patient was 5.8 mSv (4.8-7.3). The median dose received in the free-hand fluoroscopy group was 1 mGy (0.8-1.1). There was no detectable radiation level in the navigation-assisted surgery group, whereas the effective dose was 10 µGy in the free-hand fluoroscopy-guided surgery group. CONCLUSIONS: Malposition rate, both symptomatic and asymptomatic, in spinal surgery is reduced when using CT-guided placement of transpedicular instrumentation compared with placement under fluoroscopic guidance, with radiation values within the safety limits for health. Larger studies are needed to determine risk-benefit in these patients.