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.

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.

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 STRIVE Randomized Clinical Trial

BACKGROUND

Staphylococcus aureus is a global pathogen 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. This study evaluated 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, subjects 18-85 years old 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 SSI was the primary endpoint. 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, well tolerated, but despite eliciting substantial antibody responses that blocked key S aureus virulence mechanisms, was not efficacious in preventing S aureus infection. ClinicalTrials.gov: NCT02388165.

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.

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.

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.

β-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, β-(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 β-(1,3) bond linked to a β-(1,6) are considered modulators of certain biological responses. The aim of this review is to present the possible effects of β-glucans as adjuvants in the efficacy of vaccines against SARS-CoV-2 virus.

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.

Long-term safety and clinical performance of kyphoplasty and SpineJack® procedures in the treatment of osteoporotic vertebral compression fractures: a pilot, monocentric, investigator-initiated study

This pilot monocenter study in 30 patients with painful osteoporotic vertebral compression fractures compared two vertebral augmentation procedures. Over a 3-year post-surgery follow-up, pain/disability/quality of life remained significantly improved with both balloon kyphoplasty and SpineJack® techniques, but the latter allowed better vertebral body height restoration/kyphosis correction.

INTRODUCTION

Patient follow-up rarely exceed 2 years in trials comparing vertebral augmentation procedures for the treatment of painful osteoporotic vertebral compression fractures (VCFs). This pilot, investigator-initiated, prospective study aimed to compare long-term results of SpineJack® (SJ) and balloon kyphoplasty (BKP). Preliminary results showed that SJ resulted in a better restoration of vertebral heights and angles, maintained over 12 months.

METHODS

Thirty patients were randomized to SJ (n = 15) or BKP (n = 15). Clinical endpoints were analgesic consumption, back pain intensity (visual analog scale (VAS)), the Oswestry Disability Index (ODI), and quality of life (EQ-VAS score). They were recorded preoperatively, at 5 days (except EQ-VAS), 1, 3, 6, 12, and 36 months post-surgery. Spine X-rays were taken 48 h prior to the procedure and 5 days, 6, 12, and 36 months after.

RESULTS

Clinical improvements were observed with both procedures over the 3-year period without significant inter-group differences, but the final mean EQ-5D_index score was significantly in favor of the SJ group (0.93 ± 0.11 vs 0.81 ± 0.09; p = 0.007). Vertebral height restoration/kyphotic correction was still evident at 36 months with a greater mean correction of anterior (10 ± 13% vs 2 ± 8% for BKP, p = 0.007) and central height (10 ± 11% vs 3 ± 7% for BKP, p = 0.034) and a larger correction of the vertebral body angle (- 5.0° ± 5.1° vs 0.4° ± 3.4°; p = 0.003) for SJ group.

CONCLUSIONS

In this study, both techniques displayed very good long-term clinical efficiency and safety in patients with osteoporotic VCFs. Over the 3-year follow-up, vertebral body height restoration/kyphosis correction was better with the SpineJack® procedure.

Correction to: Long-term safety and clinical performance of kyphoplasty and SpineJack® procedures in the treatment of osteoporotic vertebral compression fractures: a pilot, monocentric, investigator-initiated study

The author list was incomplete. The complete list of authors is the following: D. Noriega, F. Rodrίguez-Monsalve, R. Ramajo, I.Sánchez-Lite, B. Toribio, F. Ardura. The corresponding author regrets sincerely this error. The original article got update.

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.

The efficacy of a percutaneous expandable titanium device in anatomical reduction of vertebral compression fractures of the thoracolumbar spine

OBJECTIVES

To evaluate the feasibility of a minimally invasive technique using a titanium expandable device to achieve anatomical restoration of vertebral compression fractures (VCF) of the thoracolumbar spine.

METHODS

This prospective study included 27 patients diagnosed with VCF (Magerl classification A.1.2, A.1.3, and A.3.1) of the thoracolumbar spine treated with percutaneous cement augmentation using the SpineJack® device. The study was conducted in Valladolid University Hospital, Valladolid, Spain from January to December 2012, with a minimum one-year follow up. Preoperative evaluation included visual analogue scale (VAS) for pain, and radiological assessment of the VCF using 3-dimensional computed tomography (3D-CT) scans for measurements of vertebral heights and angles. The patients were followed at 3, 6, and 12 months with clinical VAS and radiological assessments.

RESULTS

The procedure was performed in 27 patients with a mean age of 55.9 ± 17.3 years, 55.6% females. All patients underwent surgery within 6 weeks from time of injury. No procedure related complications occurred. Pain measured by VAS score decreased from 7.0 preoperatively to 3.2 within 24 hours, and remained 2.2 at 3 months, 2.1 at 6 months, and 1.5 at 12-months follow-up (p&lt;0.05). Mean height restorations for the anterior was 3.56 mm, central was 2.49, and posterior vertebral was 1.28 mm, and maintained at 12-months follow-up (p=0.001).

CONCLUSION

This new percutaneous technique for VCF has shown good clinical results in pain control and the possibility to reduce both vertebral kyphosis angles and fractured endplates seen in 3D-CT scans assessment method. Further studies are needed to confirm those results on larger cohorts with long-term follow up. 

Safety and clinical performance of kyphoplasty and SpineJack(®) procedures in the treatment of osteoporotic vertebral compression fractures: a pilot, monocentric, investigator-initiated study

Clinical performance and safety of two percutaneous vertebral cement augmentation (VA) procedures (SpineJack® and Kyphx Xpander® balloon) were compared in patients with osteoporotic compression fractures. Both techniques were safe, efficient, and led to a rapid and marked improvement in clinical signs; nevertheless, SpineJack showed better restoration of vertebral heights and angles, maintained over time.

INTRODUCTION

In patients with osteoporotic vertebral compression fractures (VCFs), both SpineJack® (SJ) and balloon kyphoplasty (BKP) led to a rapid and marked improvement in clinical signs. This pilot, monocentric, investigator-initiated, prospective study aimed to compare two percutaneous vertebral augmentation procedures in the painful osteoporotic VCF treatment.

METHODS

Thirty patients were randomized to receive SJ (n = 15) or BKP (n = 15). Analgesic consumption, back pain intensity (visual analog scale (VAS)), and Oswestry Disability Index (ODI) scores were recorded preoperatively, at 5 days and 1, 3, 6, and 12 months post-surgery. Quality of life (EQ-VAS score) was evaluated at 1, 3, 6, and 12 months. Spine X-rays were taken 48 h prior to procedure and 5 days and 6 and 12 months after.

RESULTS

SpineJack® led to a significantly shorter intervention period (23 vs 32 min; p < 0.001), a strong, rapid, and long-lasting decline in pain (94 vs 82 % at 12 months) and in functional disability (94 vs 90 % at 12 months), a greater and sustainable mean correction of anterior (12 ± 13 vs 0 ± 7 % for BKP, p = 0.003) and central height (12 ± 10 vs 2 ± 6 % for BKP, p = 0.001) at 12 months, and a larger restoration of the vertebral body angle still evident 12 months after implantation (-4.4° ± 5.8° vs 0.2° ± 3.0° for BKP; p = 0.012).

CONCLUSIONS

This pilot study showed that both techniques were safe and efficient for the osteoporotic VCF treatment. Radiological results indicate that the SpineJack® procedure has a higher potential for vertebral body height restoration and maintenance over time.

Height restoration of osteoporotic vertebral compression fractures using different intravertebral reduction devices: a cadaveric study

BACKGROUND

The treatment of osteoporotic vertebral compression fractures using transpedicular cement augmentation has grown significantly during the past two decades. Balloon kyphoplasty was developed to restore vertebral height and improve sagittal alignment. Several studies have shown these theoretical improvements cannot be transferred universally to the clinical setting.

PURPOSE

The aim of the current study is to evaluate two different procedures used for percutaneous augmentation of vertebral compression fractures with respect to height restoration: balloon kyphoplasty and SpineJack.

MATERIALS AND METHODS

Twenty-four vertebral bodies of two intact, fresh human cadaveric spines (T6-L5; donor age, 70 years and 60 years; T-score -6.8 points and -6.3 points) were scanned using computed tomography (CT) and dissected into single vertebral bodies. Vertebral wedge compression fractures were created by a material testing machine (Universal testing machine, Instron 5566, Darmstadt, Germany). The axial load was increased continuously until the height of the anterior edge of the vertebral body was reduced by 40% of the initial measured values. After 15 minutes, the load was decreased manually to 100 N. After postfracture CT, the clamped vertebral bodies were placed in a custom-made loading frame with a preload of 100 N. Twelve vertebral bodies were treated using SpineJack (SJ; Vexim, Balma, France), the 12 remaining vertebral bodies were treated with balloon kyphoplasty (BKP; Kyphon, Medtronic, Sunnyvale, CA, USA). The load was maintained during the procedure until the cement set completely. Posttreatment CT was performed. Anterior, central, and posterior height as well as the Beck index were measured prefracture and postfracture as well as after treatment.

RESULTS

For anterior height restoration (BKP, 0.14±1.48 mm; SJ, 3.34±1.19 mm), central height restoration (BKP, 0.91±1.04 mm; SJ, 3.24±1.22 mm), and posterior restoration (BKP, 0.37±0.57 mm; SJ, 1.26±1.05), as well as the Beck index (BKP, 0.00±0.06 mm; SJ, 0.10±0.06), the values for the SpineJack group were significantly higher (p<.05) CONCLUSION: The protocols for creating wedge fractures and using the instrumentation under a constant preload of 100 N led to reproducible results and effects. The study showed that height restoration was significantly better in the SpineJack group compared with the balloon kyphoplasty group. The clinical implications include a better restoration of the sagittal balance of the spine and a reduction of the kyphotic deformity, which may relate to clinical outcome and the biological healing process.