Kyphoplasty with intravertebral reduction devices associated with better height restoration and greater kyphosis correction than kyphoplasty with balloons.

Kyphoplasty (KP) with intravertebral reduction devices (IRD) was reported to be associated with better radiological outcomes than KP with balloons (BK) for osteoporotic vertebral compression fractures (OVCFs). However, the mechanical factors that contribute to the radiological benefits of IRDs require further investigation. To probe the mechanical factors, this retrospective matched cohort study was designed, including the older patients with painful OVCFs and treated with KP. We compared the clinical and radiological outcomes between KP with an IRD and BK, where vertebral body height and kyphotic angle of the cemented vertebrae were measured pre- and postoperatively; clinical outcomes were collected by telephone interviews. The restoration and maintenance ratio suggested that IRDs were associated with favorable effects long-term wise in anterior to middle vertebral body and kyphosis than BK in patients. The gathered results concluded the radiological benefits of IRD regarding both its efficient restoration and maintenance in vertebrae.

Percutaneous mesh-container-plasty for osteoporotic thoracolumbar burst fractures: A prospective, nonrandomized comparative study.

OBJECTIVE: This study aimed to compare the clinical and radiological results of percutaneous mesh-container-plasty (PMCP) versus percutaneous kyphoplasty (PKP) in the treatment of osteoporotic thoracolumbar burst fractures. METHODS: A prospective study of 122 patients with osteoporotic thoracolumbar burst fractures was conducted. The patients were nonrandomly assigned to receive PKP (62; 16 men, 46 women) and PMCP (60; 14 men, 46 women). The epidemiological data, surgical outcomes, and clinical and radiological features were compared between the 2 groups. Cement leakage, height restoration, deformity correction, canal compromise, and cement distribution were calculated from the radiographs. Visual pain analog scale (VAS), the Oswestry disability index (ODI), and short-form 36 health survey domains role physical (SF-36 rp) and bodily pain (SF-36 bp) were calculated before surgery and immediately and 2 years after surgery. RESULTS: Although VAS, ODI, SF-36 bp, and SF-36 rp scores improved from 7 (6-9), 71.28±16.38, 22 (0-32), and 25 (0-50) preoperatively to 2 (1-3), 20.02±8.97, 84 (84-84), and 75 (75-100) immediately postoperatively in the PMCP group (p<0.05) and from 7 (6-8), 71.40±13.52, 22 (10.5-31.75), and 25 (0-50) preoperatively to 2 (1-3), 21.78±11.21, 84 (84-84), and 75 (75-100) immediately postoperatively in the PKP group (p<0.05), there was no difference between the 2 groups. The mean cost in the PKP group was less than that in the PMCP group ($5109±231 vs. $6699±201, p<0.05). Anterior, middle, and posterior vertebral body height ratios in the PMCP group were greater than those in the PKP group postoperatively (88.44%±3.76% vs. 81.10%±11.78%, 86.15%±3.50% vs. 82.30%±11.02%, and 93.91%±3.01% vs. 91.43%±6.71%, respectively, p<0.05). The Cobb angle in the PMCP group was lower than that in the PKP group postoperatively (6.67°±4.39° vs. 8.99°±4.06°, p<0.05). Cement distribution in the PMCP group was higher than that in the PKP group (30.48%±5.62% vs. 27.18%±4.87%, p<0.05). Cement leakage was observed to be lesser in the PMCP group (2/60) than in the PKP group (10 vs. 62, p<0.05). CONCLUSION: Both PKP and PMCP treatments seem to have significant ability in pain relief and functional recovery. Despite its higher cost, PMCP treatment may have a better inhibition ability of cement leakage, cement distribution, height restoration, and improvement in segmental kyphosis than PKP treatment for osteoporotic thoracolumbar burst fractures. LEVEL OF EVIDENCE: Level II, Therapeutic Study.

Risk Factors for Cement Leakage and Adjacent Vertebral Fractures in Kyphoplasty for Osteoporotic Vertebral Fractures.

PURPOSE: Cement leakage and adjacent vertebral fractures are not uncommon after percutaneous augmentation. However, conclusive identification of risk factors for postprocedural complications remains elusive. The anticipation of leakage and successive fractures through the identification of risk factors will help physicians better inform patients of potential complications and establish procedural refinements key to risk reduction. The aim of this retrospective study was to summarize available reports of the risk factors for cement leak and adjacent vertebral fracture in or after kyphoplasty for osteoporotic vertebral compression fractures. METHODS: A total of 102 cases of bilateral percutaneous kyphoplasty (PKP), performed between January 2014 and December 2016, were retrospectively reviewed. Each case surveyed in this review included a minimum 1-year follow-up and data on age, sex, bone mineral density, Visual Analog Scale score, preoperative compression rate, kyphotic angle, treatment time, the volume of cement, and the intactness of the vertebral posterior wall (computed tomography scan) were collected. Pearson χ test and independent samples test were used to determine the relative risk factors of cement leak and adjacent vertebral fracture in patient subsets. RESULTS: Diabetic status and alteration in the Cobb angle after PKP exhibited a statistically significant correlation with the incidence of new adjacent vertebral fracture (group B) (P<0.05). In addition, the integrity of vertebral walls (P=0.001) and the volume of injected cement (P=0.026) significantly boosted the potential risk of cement leakage (P<0.05), although these variables did not associate with the adjacent fracture. Additional examined variables, including age, sex, Visual Analog Scale scores, number of fractures were not significantly associated with leakage or adjacent vertebral fracture risk. CONCLUSIONS: Diabetes and the alteration of the Cobb angle following PKP are factors positively related to the occurrence of postoperative adjacent vertebral fractures. It is also demonstrated that the integrity of vertebral walls and average volumes of injected cement are the possible risk factors of cement leakage while performing the PKP.

Comparison of Radiation Exposure of the Surgeon in Minimally Invasive Treatment of Osteoporotic Vertebral Fractures - Radiofrequency Kyphoplasty versus Balloon Kyphoplasty with Cement Delivery Systems (CDS). / Vergleich der Strahlenbelastung des Operateurs bei der minimalinvasiven Versorgung osteoporotischer Wirbelkörperfrakturen ­ Radiofrequenz-Kyphoplastie versus Ballon-Kyphoplastie mit Cement-delivery-Systems (CDS).

The aim of the present study was to compare the radiation exposure of the surgeon when using two different kyphoplasty systems for the minimally invasive treatment of osteoporotic vertebral body fractures. There was a preliminary investigation study by a Belgian working group from the ORAMED project (2010), which served as the basis and showed a dose reduction for the surgeon when using a balloon kyphoplasty system with cement delivery systems (CDS). MATERIALS AND METHODS: A bipedicular balloon kyphoplasty system (Medtronic GmbH) with CDS and a unipedicular radiofrequency kyphoplasty system (StabiliT, DFine Europe GmbH) were used in solitary fractures in the thoracolumbar junction in 20 patients each. The patient groups were relatively homogeneous with a mean age of 76.9 years for balloon kyphoplasty and 75 years for radiofrequency kyphoplasty. As expected, the proportion of woman was higher in both groups. The mean BMI value was higher in the radiofrequency kyphoplasty group, and the patient with the highest BMI was also in this group. The workflows were defined in three steps. The working time and the fluoroscopic time were measured in the individual work steps and the dose was measured over all work steps by TLD chips (thermoluminescence detector) on the forehead, on the X-ray apron, on both wrists and on the left ankle. The dose area product was registered for the entire procedure. RESULTS: In step 2, the main differences were found in working time and fluoroscopy time in transit. The difference was due to the bipedicular puncture for balloon kyphoplasty and the change of the working cannula, while only a unipedicular puncture was needed in radiofrequency kyphoplasty. The total fluoroscopy time over all procedures was three times longer than in balloon kyphoplasty and this was also reflected in the dose area product, which was more than twice that. The measured surface doses for the lenses were four times higher in balloon kyphoplasty. For the left wrist, the values for balloon kyphoplasty were about 8 times higher. CONCLUSION: Overall, from a radiophysical perspective, the use of a unipedicular kyphoplasty system must be recommended. Should balloon kyphoplasty be used for medical reasons, all radiation protection products (lead gloves, lead glass, radiation protection goggles and CDS) should be used, the surface doses for both hands must be detected by a ring dosimeter and the lens dose must be recorded and documented by a TLD on the radiation protection goggles. KEY POINTS: · Unipedicular kyphoplasty systems would be the better options for radiation protection reasons.. · Specific medical indications may justify the use of a bipedicular kyphoplasty system on a case-by-case basis.. · The use of a ballon kyphoplasty system without CDS is no longer recommended.. · When using a bipendicular kyphoplasty system, the surface doses for the hands and the lens must be documented.. CITATION FORMAT: · Reißberg S, Lüdeke L, Fritsch M. Comparison of Radiation Exposure of the Surgeon in Minimally Invasive Treatment of Osteoporotic Vertebral Fractures - Radiofrequency Kyphoplasty versus Balloon Kyphoplasty with Cement Delivery Systems (CDS). Fortschr Röntgenstr 2020; 192: 59 - 64.

Armed Kyphoplasty: An Indirect Central Canal Decompression Technique in Burst Fractures.

BACKGROUND AND PURPOSE: Burst fractures are characterized by middle column disruption and may feature posterior wall retropulsion. Indications for treatment remain controversial. Recently introduced vertebral augmentation techniques using intravertebral distraction devices, such as vertebral body stents and SpineJack, could be effective in fracture reduction and fixation and might obtain central canal clearance through ligamentotaxis. This study assesses the results of armed kyphoplasty using vertebral body stents or SpineJack in traumatic, osteoporotic, and neoplastic burst fractures with respect to vertebral body height restoration and correction of posterior wall retropulsion. MATERIALS AND METHODS: This was a retrospective assessment of 53 burst fractures with posterior wall retropulsion and no neurologic deficit in 51 consecutive patients treated with armed kyphoplasty. Posterior wall retropulsion and vertebral body height were measured on pre- and postprocedural CT. Clinical and radiologic follow-up charts were reviewed. RESULTS: Armed kyphoplasty was performed as a stand-alone treatment in 43 patients, combined with posterior instrumentation in 8 and laminectomy in 4. Pre-armed kyphoplasty and post-armed kyphoplasty mean posterior wall retropulsion was 5.8 and 4.5 mm, respectively (P < .001), and mean vertebral body height was 10.8 and 16.7 mm, respectively (P < .001). No significant clinical complications occurred. Clinical and radiologic follow-up (1-36 months; mean, 8 months) was available in 39 patients. Three treated levels showed a new fracture during follow-up without neurologic deterioration, and no retreatment was deemed necessary. CONCLUSIONS: In the treatment of burst fractures with posterior wall retropulsion and no neurologic deficit, armed kyphoplasty yields fracture reduction, internal fixation, and indirect central canal decompression. In selected cases, it might represent a suitable minimally invasive treatment option, stand-alone or in combination with posterior stabilization.

Prospective randomized comparison of early versus newer-generation vertebral access devices for kyphoplasty.

INTRODUCTION: Kyphoplasty is an established method of treating osteoporotic vertebral body compression fractures. In recent years, several techniques to enhance the efficiency and outcomes of this surgery have been developed and implemented in clinical practice. In the present study, we assess the impact of two new access instruments on overall operation time and the administered dose area product in comparison with the standard access instrument used in our clinical practice. The two newer comparator devices have been designed with the intention of streamlining intraoperative workflow by omitting several procedural steps. MATERIALS AND METHODS: This was a single-center prospective randomized trial investigating three distinct access instruments compatible with the Joline Allevo balloon catheter system. Specifically, two newer access devices marketed as being able to enhance surgical workflow (Joline RapidIntro Vertebra Access Device with a trocar tip and Joline SpeedTrack Vertebra Introducer Device with a short, tapered tip) were compared with the older, established Joline Vertebra Access Device from the same firm. Consecutive eligible and consenting patients scheduled to undergo kyphoplasty for osteoporotic vertebral compression fracture refractory to conservative, medical treatment during the period May 2012-August 2015 were randomized to receive surgery using one of the three devices. Besides the use of the trial instruments, all other preoperative, intraoperative and postoperative care was delivered according to standard practice. RESULTS: 91 kyphoplasties were performed on 65 unique patients during the study period. The median operation time across the three groups was 29 min (IQR 22.5-35.5) with a median irradiation time of 2.3 min (IQR 1.2-3.4). The median patient age was 74 years (IQR 66-80). The groups did not significantly differ in terms of age (p = 0.878), sex (p = 0.37), T score (p = 0.718), BMI (p = 0.285) or the applied volume of cement (p = 0.792). There was no significant difference between the treatment groups with respect to surgical duration (p = 0.157) or dose area product (p = 0.913). CONCLUSIONS: Although use of the two newer-generation access instruments were designed to involve fewer unique steps per operation, their use was not associated with reduction in surgical duration, irradiation time or dose area product administered compared with the older, established vertebral access device. Care should be taken to evaluate the impact of new instruments on key surgery-related parameters such as surgical duration and radiation exposure and claims made about new instruments should be assessed a structured fashion.

Stent-screw-assisted internal fixation: the SAIF technique to augment severe osteoporotic and neoplastic vertebral body fractures.

OBJECTIVES: To describe a new technique to obtain minimally invasive but efficient vertebral body (VB) reconstruction, augmentation, and stabilization in severe osteoporotic and neoplastic fractures, combining two pre-existing procedures. The implant of vertebral body stents (VBS) is followed by insertion of percutaneous, fenestrated, cement-augmented pedicular screws that act as anchors to the posterior elements for the cement/stent complex. The screws reduce the risk of stent mobilization in a non-intact VB cortical shell and bridge middle column and pedicular fractures. This procedure results in a 360° non-fusion form of vertebral internal fixation that may empower vertebral augmentation and potentially avoid corpectomy in challenging fractures. PROCEDURE DETAILS: This report provides step-by-step procedural details, rationale, and proposed indications for this procedure. The procedure is entirely percutaneous under fluoroscopic guidance. Through transpedicular trocars the VBS are inserted, balloon-expanded and implanted in the VB. Over k-wire exchange the transpedicular screws are inserted inside the lumen of the stents and cement is injected through the screws to augment the stents and fuse the screws to the stents. APPLICATIONS: This technique may find appropriate applications for the most severe osteoporotic fractures with large clefts, high-degree fragmentation and collapse, middle column and pedicular involvement, and in extensive neoplastic lytic lesions. CONCLUSIONS: Stent-Screw-Assisted Internal Fixation (SAIF) might represent a minimally invasive option to obtain VB reconstruction and restoration of axial load capability in severe osteoporotic and neoplastic fractures, potentially obviating the need for more invasive surgical interventions in situations that would pose significant challenges to standard vertebroplasty or balloon kyphoplasty.

Radiological evaluation of kyphoplasty with an intravertebral expander after osteoporotic vertebral fracture.

Spinal deformities due to osteoporotic vertebral compression fractures can be reduced by balloon kyphoplasty, but the correction may be partly lost when the balloon is deflated. The present study aimed to evaluate an intravertebral expander developed to reduce and maintain vertebral body height while cement is injected to correct spinal deformities due to osteoporotic vertebral fractures. The study included 31 osteoporotic vertebral body fractures in 31 patients, classified as A1 according to the AO classification, who underwent kyphoplasty using an intravertebral expander. The kyphosis angle was significantly corrected from 13.4 degrees prior to kyphoplasty to 10.8 degrees (p < 0.01) after surgery, but this correction was lost at 12 months (13.3 degrees). The correction of the kyphosis angle best correlated with the pre-operative mobility of the fracture (r = 0.59, p < 0.01), and the loss of the kyphosis improvement correlated with the amount of correction (r = 0.49, p = 0.01). All patients, except for six with adjacent vertebral fractures, experienced significant pain reduction (VAS 8.7 pre-operatively and 2.0 at 12 months; p < 0.01), and the pain was not affected by the correction of the spinal deformity or the loss of correction in the follow-up period. These results suggest that the mobility of the fracture mainly determines the extent of deformity correction rather the device used for reduction, and greater corrections are at increased risk for losing the improvement. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:457-465, 2019.

Utility of Cement Augmentation via Percutaneous Fenestrated Pedicle Screws for Stabilization of Cancer-Related Spinal Instability.

BACKGROUND: Cancer patients experience pathological fractures and the typical poor bone quality frequently complicates stabilization. Methods for overcoming screw failure include utilization of fenestrated screws that permit the injection of bone cement into the vertebral body to augment fixation. OBJECTIVE: To evaluate the safety and efficacy of cement augmentation via fenestrated screws. METHODS: A retrospective chart review of patients with neoplastic spinal instability who underwent percutaneous instrumented stabilization with cement augmentation using fenestrated pedicle screws. Patient demographic and treatment data and intraoperative and postoperative complications were evaluated by chart review and radiographic evaluation. Prospectively collected patient reported outcomes (PRO) were evaluated at short (2- <6 mo) and long term (6-12 mo). RESULTS: Cement augmentation was performed in 216 fenestrated pedicle screws in 53 patients. Three patients required reoperation. One patient had an asymptomatic screw fracture at 6 mo postoperatively that did not require intervention. No cases of lucency around the pedicle screws, rod fractures, or cement extravasation into the spinal canal were observed. Eight cases of asymptomatic, radiographically-detected venous extravasation were found. Systemic complications included a pulmonary cement embolism, a lower extremity deep vein thrombosis, and a postoperative mortality secondary to pulmonary failure from widespread metastatic pulmonary infiltration. Significant improvement in PRO measures was found in short- and long-term analysis. CONCLUSION: Cement augmentation of pedicle screws is an effective method to enhance the durability of spinal constructs in the cancer population. Risks include cement extravasation into draining blood vessels, but risk of clinically significant extravasation appears to be exceedingly low.

Clinical application of the pedicle in vitro restorer in percutaneous kyphoplasty.

BACKGROUND: Percutaneous kyphoplasty (PKP) is widely applied for the treatment of osteoporotic vertebral compression fractures (OVCFs) and has achieved satisfactory clinical results. With the accumulation of clinical cases and prolonged follow-up times, the inability to reconstruct vertebral height defects has attracted more and more attention. A comparison of clinical effects was retrospectively reviewed in 72 patients who underwent simple PKP or pedicle in vitro restorer (PIVR) combined with PKP to discuss the clinical application of self-developed PIVR used in PKP. METHODS: From August 2013 to August 2016, 72 patients with OVCFs were treated surgically, with 30 patients undergoing PKP (group A) and 42 undergoing PIVR combined with PKP (group B). Operation-related situations, radiological data, and related scores were compared between the two groups by corresponding statistical methods. RESULTS: Bone cement was successfully injected into 72 vertebral bodies. Sixty-three cases were followed up for an average of 14 months. There were significant differences between the two groups in the improvement of the height of the vertebral body, sagittal Cobb angle, and visual analogue scale (VAS) 1 week after the operation (P < 0.05), and the improvements of group B were better than those in group A. The cement leakage ratio was significantly different between the two groups (P < 0.05). The Oswestry Disability Index (ODI) at last follow-up was significantly different between the two groups (P < 0.05). There was no significant difference in the incidence of recurrent vertebral fractures between the two groups at the last follow-up (P > 0.05). CONCLUSION: PIVR combined with PKP can overcome the limitations of PKP alone, that is, hardly restoring vertebral height and height being easily lost again with balloon removal. The combined method can also restore the vertebral fractures to a satisfactory height and effectively maintain the stability of the spine, which improves the long-term quality of life of patients. Thus, PIVR combined with PKP is a better choice for patients with OVCFs.

Unilateral versus bilateral percutaneous balloon kyphoplasty for osteoporotic vertebral compression fractures: A systematic review of overlapping meta-analyses.

BACKGROUND: Unilateral and bilateral percutaneous balloon kyphoplasty (PKP) are 2 main approaches for the treatment of patients with osteoporotic vertebral compression fractures (OVCFs). Numerous published systematic reviews and meta-analyses evaluating the effectiveness of 2 approaches remain inconclusive. In order to propose a significant principle to make decisions for comparing clinical safety and efficacy of unilateral versus bilateral PKP for treating OVCFs patients based on the currently best available evidence, a systematic review of overlapping meta-analysis was conducted. METHODS: Three electronic databases, Pubmed/Medline, Embase2 and the Cochrance Library, were searched systematically to retrieve and identify all eligible systematic reviews and meta-analyses comparing unilateral and bilateral PKP for the treatment of patients with OVCFs. Only systematic reviews or meta-analyses with an exclusively pooled analysis of randomized controlled trials (RCTs) met the minimum eligibility criteria in this investigation. The Oxford Levels of Evidence, Jadad algorithm and Assessment of Multiple Systematic Reviews (AMSTAR) instrument were adopted for evaluation of the methodological quality for each included literature to select currently best available evidence. RESULTS: Screening determined that out of 2159, 9 meta-analyses with level II or III of evidence met the inclusion criteria in the systematic review of overlapping meta-analyses. The multiple systematic reviews scores ranged from 8 to 9 with a mean of 8.55 (median 8.5). According to the search process and selection strategies of the Jadad algorithm, a meta-analysis by Feng et al with the best available evidence (12 RCTs and an AMSTAR score of 9) demonstrated that unilateral and bilateral PKP are both nice choices for the treatment of patients with OVCFs, and no significant differences were revealed in clinical scores, radiological outcomes, and quality of life with long-term follow-up. However, compared with bilateral PKP, unilateral PKP produced a shorter surgery time, smaller dosage of cement, lower risk of cement leakage, and relieved a higher degree of intractable pain at short-term follow-up after surgery. CONCLUSION: Unilateral percutaneous balloon kyphoplasty is more advantageous and superior to bilateral percutaneous kyphoplasty, and should be considered an effective option for the treatment of patients with osteoporotic vertebral compression fractures.

Balloon kyphoplasty and additional anterior odontoid screw fixation for treatment of unstable osteolytic lesions of the vertebral body C2: a case series.

BACKGROUND: Unstable osteolytic lesions of the occipitocervical junction are rare and may occur in hematological malignancy or vertebral hemangioma, among others. Different case reports have been published about vertebroplasty for treatment of spinal metastases of the upper cervical spine. Only few cases concern balloon kyphoplasty of C2. We present a consecutive case series including four patients with an osteolytic lesion of the dens axis and describe a technical note for balloon kyphoplasty of C2 and an additional anterior odontoid screw fixation. METHODS: Four consecutive patients with an osteolytic lesion of the vertebral body of C2 were treated by anterior balloon kyphoplasty and additional anterior odontoid screw fixation of the dens axis. The radiological imaging showed a lytic process of the vertebral body C2 with no vertebral collapse but involvement of more than 50% of the vertebral body in all patients. RESULTS: Two cases of potentially unstable osteolytic lesions of C2 by myeloma, one case with metastatic osteolytic lesion of C2 by adenocarcinoma of the colon and one patient with vertebral hemangioma located in C2 were presented to our clinic. In all cases, surgical treatment with an anterior balloon kyphoplasty of C2 and an additional anterior, bicortical odontoid screw placement was performed. Control x-rays showed sufficient osteosynthesis and cement placement in the vertebral body C2. DISCUSSION: Anterior balloon kyphoplasty and anterior odontoid screw placement is a safe treatment option for large osteolytic lesions of C2. The additional odontoid screw placement has the advantage of providing more stabilization and may prevent late complications, like odontoid fractures. For patients with potentially unstable or large osteolytic lesions of the dens without spinal cord compression or neurological symptoms we recommend the placement of an anterior odontoid screw when performing a balloon kyphoplasty. LEVEL OF EVIDENCE: - IV: retrospective or historical series.

Nonfusion Intracorporeal Enhancement System for the Treatment of Osteoporotic Vertebral Compression Fractures-Preliminary Clinical Result of a Novel Technique.

OBJECTIVE: This study sought to determine whether implantation of a newly designed nonfusion intracorporeal enhancement (NICE) system is an effective and safe way to treat osteoporotic vertebral compression fracture (OVCF). METHODS: Thirteen patients with OVCF (10 women, 3 men; mean age 69 years, T11-L4) were included. From June 2014 to June 2016, all patients were treated with the NICE system. The clinical and radiologic results were evaluated preoperatively, postoperatively, and at 24 months follow-up based on the visual analog scale and the Oswestry Disability Index, radiography, magnetic resonance imaging, and computed tomography (height of fractured body and kyphosis Cobb angle). RESULTS: There was a significant improvement in pain intensity (visual analog scale score decreased from 8.3 preoperatively to 2.2 postoperatively, and decreased to 1.5 twenty-four months postoperatively). Also, a significant reduction was observed in that the mean Oswestry Disability Index decreased from 71.9% preoperatively to 17.6% after 24 months. The mean Cobb angle had a significant improvement, which decreased from 6.6° preoperatively to 1.3° postoperatively and then decreased to 1.2° after 24 months. Height of fractured body improved significantly from 66.4% to 86.5% and slightly decreased to 82.4% after 24 months. No specific complications were identified to be associated with this technique. CONCLUSIONS: With a low complication rate, the clinical midterm results are satisfactory. The treatment of symptomatic OVCF with the NICE system is a safe and effective procedure.

New Implant-Based Technologies in the Spine.

Vertebral compression fractures (VCFs) may result in a kyphotic deformity which can cause potential systemic complications secondary to respiratory and gastrointestinal dysfunction. The use of implants in the spine for VCF treatment represents a paradigm shift away from cement injection on its own, aiming to combine the analgesic and stabilizing effect of injecting cement into the vertebral body with vertebral height restoration and kyphotic angle correction. Spine implants which can be used for VCF treatment include stents, jacks, PEEK cages and fracture reduction systems. Lumbar spinal stenosis (LSS) with neurogenic intermittent claudication is one of the most commonly occurring spinal conditions, usually affecting people older than 50, which can cause disability and a reducted quality of life. Percutaneous interspinous spacers for the relief of symptoms caused by spinal stenosis can be used in patients who are not surgical candidates. The purpose of this article is to describe the basic concepts of spinal implantation in patients with VCF or spinal stenosis. The role of biomechanics and the different types of implants will be described. Controversies concerning techniques and products will be addressed. Finally, the necessity for an individually tailored approach for the use of different implants in different cases and anatomic locations will be emphasized.

The pedicle instrumentation and percutaneous elevation (Pi.Pe): a new cementless surgical technique in type A post-traumatic vertebral fractures.

PURPOSE: To investigate if bone substitutes are strictly necessary to restore the vertebral body height and improve the clinical outcome, in patients with thoracolumbar or lumbar AO type A post-traumatic vertebral fractures, managed with balloon kyphoplasty combined with posterior screw and rod system. METHODS: 105 patients with post-traumatic thoracolumbar spine fracture were recruited. At baseline, the patients underwent a CT and an MRI of the spine. Clinical evaluation was performed, using the Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI), at baseline, 48 h after surgery, at 3-month follow-up (FU), 6-month FU, 48 h after the instrumentation removal and at 24-month FU. At each FU, VK, regional kyphosis (RK), central wall (MH/PH) and anterior wall (AH/PH) heights were assessed on lateral spine X-rays. At 6-month FU, a CT scan of the spine was performed to investigate the fracture healing. The posterior instrumentation was removed 7 months after surgery (range 6-10 months). RESULTS: A significant reduction of mean VAS (p < 0.05) and ODI (p < 0.05) was observed after surgery; no impairment of these scores was observed after the instrumentation removal. A significant correction of VK, RK, AH/PH and MH/PH was recorded after surgery; no significant changes of these values were noticed at subsequent FU. After the instrumentation removal, only an RK impairment was recorded, but it was not significant. CONCLUSIONS: PMMA or bone substitutes are not necessary to keep the reduction of the endplate obtained with the balloon tamp, when BK is performed in the association with posterior percutaneous pedicle screws instrumentation. These slides can be retrieved under Electronic Supplementary Material.

Minimally invasive fixation techniques for thoracolumbar fractures: comparison between percutaneous pedicle screw with intermediate screw (PPSIS) and percutaneous pedicle screw with kyphoplasty (PPSK).

PURPOSE: To assess and compare the efficacy of two minimally invasive techniques (percutaneous pedicle screw with intermediate screw vs. percutaneous pedicle screw with kyphoplasty) for spinal fracture fixation by comparing the segmental kyphosis and vertebral kyphosis angles after trauma before surgery, after surgery, and at 4-month and 12-month follow-up. METHODS: Data from 49 patients without neurological deficit treated by either percutaneous pedicle screw with intermediate screw or percutaneous pedicle screw with kyphoplasty were retrospectively analysed. The segmental kyphosis and vertebral kyphosis angles over time were calculated and correlated with the type of procedure, AO classification, lumbar or thoracic site and the age and sex of the patients. RESULTS: After surgery, both techniques were found to be efficacious means of bringing about a significant correction of the segmental kyphosis angle (p = 0.002) and a just significant correction of the vertebral kyphosis angle (p = 0.06), although less effectively in thoracic fractures (p = 0.004). At follow-up, the vertebral kyphosis angle was stable in both groups, while there was a significant loss of segmental kyphosis angle stability in the percutaneous pedicle screw with kyphoplasty group at 1 year (p = 0.004); fractured thoracic vertebrae maintained a greater vertebral kyphosis angle (p = 0.06) and segmental kyphosis angle (p < 0.001), than the lumbar. CONCLUSION: At 1 year after surgery, the use of intermediate screws in fractured vertebrae seemed to maintain a more efficacious correction with respect to kyphoplasty, although thoracic fracture sites appear to be associated with greater post-traumatic segmental kyphosis and lesser stability in the long term after both percutaneous surgical techniques.

Injectable, biomechanically robust, biodegradable and osseointegrative bone cement for percutaneous kyphoplasty and vertebroplasty.

PURPOSE: Poly(methyl methacrylate) (PMMA) cement is widely used for percutaneous kyphoplasty and vertebroplasty (PKP and PVP) but possesses formidable shortcomings due to non-degradability. Here, a biodegradable replacement is developed. METHODS: Calcium phosphate cement (CPC) was redesigned by incorporating starch and BaSO4 (new cement named as CPB). The biomechanical, biocompatibility, osseointegrative and handling properties of CPB were systematically evaluated in vitro and in vivo by the models of osteoporotic sheep vertebra, rat subcutaneous implantation and rat femoral defect. RESULTS: CPB revealed appropriate injectability and setting ability for PKP and PVP. More importantly, its biomechanical strengths measured by in vitro and in vivo models were not less than that of PMMA, while its biodegradability and osseointegrative capacities were significantly enhanced compared to PMMA. CONCLUSIONS: CPB is injectable, biomechanically robust, biodegradable and osseointegrative, demonstrating revolutionary potential for the application in PKP and PVP.

[Venous Paravasation After Augmentation of Pedicle Screws - An Underestimated Risk]. / Venöse Paravasate nach Augmentation von Pedikelschrauben ­ ein unterschätztes Risiko.

Cement-augmented pedicle screws can increase the stability of fixators for unstable vertebral fractures in the elderly. Fixators can be inserted quickly and with minimally invasive techniques, reducing surgical risks. From March 2012 until July 2014, we treated 40 patients with percutaneous augmented fixators for unstable vertebral fractures. Average age was 77.5 years. During the six month observation period, no patients died. There were no neurological deficits. On VAS, average pain decreased from 8.5 to 4.1 points postoperatively. The average Cobb angle of 4.1° was improved after surgery. After 6 months, bony consolidation yielded angles of 1 to 4°, average 2.6°. There was often venous extravasation of cement leaking from the augmented vertebrae, even extending to pulmonary embolism. The emboli were usually asymptomatic. We report a case where the patient required resuscitation immediately after cement application because of pulmonary emboli. The patient survived because of the immediately implemented critical care measures. Little has been published about this risk, which is underestimated despite increasing numbers of augmented fixator operations. The risk can be reduced with slower cement injection, smaller cement applicators, and short term positive pressure ventilation with PEEP.

The Vertect Jack Device: A new method for augmentation of vertebral fractures. Clinical study with comparisons to kyphoplasty.

BACKGROUND: Kyphoplasty is a proven minimally invasive procedure for the treatment of patients with osteoporotic fractures. By augmentation of fractured vertebral body, however, a very large portion of the intervertebral structures will be destroyed. With the help of a new device (Vertect Jack Device), the erection of the vertebral body will be carried out more gentle. OBJECTIVE: In the present study, the new method should be clinically tested for efficacy and safety for the first time. As a comparison results of previous treatments with kyphoplasty were used. METHODS: For Vertect Jack Device study patients with painful vertebral fractures were selected in which conservative treatment had not yielded sufficient results. For comparison random data from the records of patients who had been treated with kyphoplasty were selected. The Vertect Jack Device was placed under the central fractures and then erected. After having restorted the vertebral height the device was removed and cement injected. Clinical and radiological examinations were carried out before and after 1,3, and 6 months. RESULTS: In the Vertect Jack Device Group the data of 40 patients were evaluated. For group 2 (kyphoplasty) 50 patients were selected. There was a significant difference in the duration of the surgery (Group 1: 27.4, Group 2: 45.9 minutes). A significant difference of 20 mm with regard to the reduction of VAS scores (0-100 mm pain intensity) was detected. Under the application of the Vertect Jack Device an average increase of 3.1 mm of vertebral height was achieved. In group 2, the erection averaged 0.4 mm. A correlation between the postoperative change of vertebral body height and VAS scores could not be detected in both groups. CONCLUSIONS: The comparative analysis of this study shows that promising results can be achieved with the augmentation of vertebral fractures with the Vertect Jack Device. When compared with kyphoplasty, advantages show in terms of targeted and thus more gentle application possibility and better pain relief over a period of 6 months after surgery. Further study results should help to demonstrate the efficacy and tolerability of the new method.

[Effect of remote controlled injection manipulator system assisted percutaneous kyphoplasty for treatment of rupture of posterior vertebral osteoporotic vertebral fracture].

Objective: To evaluate the effect of remote controlled injection manipulator system (RCIM) assisted percutaneous kyphoplasty (PKP) for the treatment of rupture of posterior vertebral osteoporotic vertebral fracture by comparing with intermittent hand bolus injection of bone cement during operation. Methods: Between September 2010 and January 2016, a retrospective analysis was made on the clinical data of 48 senile patients with single segment rupture of the posterior vertebral osteoporotic thoracolumbar fracture undergoing PKP who accorded with the inclusion criteria. Of 48 patients, 22 received intermittent hand bolus injection of bone cement in the control group, and 26 received RCIM assisted bone cement perfusion in the trial group. There was no significant difference in age, gender, duration of disease, causes of injury, implicated vertebral bodies, bone mineral density T value, pain duration, preoperative visual analogue scale (VAS), relative vertebral body height in the anterior part, and posterior convex Cobb angle between groups ( P>0.05). The bone cement perfusion time, the radiation dose of both doctors and patients, and the amount of bone cement injection were recorded; treatment effects were evaluated based on VAS score, posterior convex Cobb angle, relative ver-tebral body height in the anterior part, ratios of bone cement diffusion area and bone cement leakage rate. Results: The patients were followed up for 6 months; no complications of toxic effect of bone cement, spinal cord or nerve root injuries, infection and vascular embolization occurred during follow-up period. There was no significant difference in bone cement injection amount and radiation dose of doctors between groups ( P>0.05), but bone cement perfusion time, ratios of bone cement diffusion area, and radiation dose of patients were significantly lower in the trial group than the control group ( P<0.05). Bone cement leakage was observed in 6 cases of the control group (27.27%) and 2 cases of the trial group (7.69%), showing significant difference between groups ( χ2=4.850, P=0.029); no cement leakage into the spinal canal was found in both groups. VAS score, relative vertebral body height in the anterior part, and posterior convex Cobb angle were significantly improved at 3 days and 6 months after operation when compared with preoperative ones ( P<0.05), but no significant difference was observed in the above indexes between groups at 3 days and 6 months after operation ( P>0.05). Conclusion: Satisfactory effectiveness can be achieved by applying RCIM assisted PKP for the treatment of rupture of posterior vertebral osteoporotic vertebral fracture. RCIM can shorten perfusion time, reduce radiation dose, and decrease incidence of bone cement leakage.