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

Early-Onset Adjacent Vertebral Fractures after Balloon Kyphoplasty and SpineJack Kyphoplasty for the Management of Single-Level Thoracolumbar Vertebral Compression Fractures

BACKGROUND

 The aim of this study was to evaluate the risk factors contributing to early-onset adjacent level fractures (ALFs) occurring within 1 month following either balloon kyphoplasty (BKP) or SpineJack kyphoplasty (SJ) for the treatment of thoracolumbar vertebral compression fractures (TLVCFs).

METHODS

 This retrospective analysis enrolled patients with single-level TLVCFs (T11-L2) who underwent either BKP or SJ between July 2013 and June 2019. We recorded the ALF occurrences within 1 month. Age, osteoporosis, severity and shape of TLVCFs, and surgical type were compared between patients with and without early-onset ALFs.

RESULTS

 Altogether, 106 TLVCF patients were enrolled, comprising 64 BKP and 42 SJ cases. We observed 19 early-onset ALFs, with 9 and 10 cases in the BKP and SJ, respectively. Patients with early-onset ALFs have significantly more severe TLCVFs (severe vs. mild, 25 vs. 0%, p = 0.055), and wedge-shaped TLVCFs (26.47 vs. 2.63%, p = 0.002), older age (81.05 vs. 73.34 years, p < 0.001), and kyphoplasty performed within 1 month are risk factors for early-onset ALFs (26.92 vs. 9.26%, p = 0.018). Univariable analysis showed that kyphoplasty timing within 1 month (odds ratio [OR]: 0.193; p = 0.008), wedge-shaped TLVCFs (OR: 5.358; p = 0.036), and advanced age (OR: 1.119; p = 0.001) are significant risk factors for early-onset ALFs.

CONCLUSIONS

 The occurrence rate of early-onset ALFs between BKP or SJ techniques in treating TLVCFs does not differ. Preoperative wedge-shaped TLVCFs, advanced age, and early treatment within 1 month are the risk factors for early-onset ALFs following kyphoplasty for TLVCFs.

EFFECTIVENESS AND SAFETY OF SPINEJACK SYSTEM IN THE MANAGEMENT OF VERTEBRAL FRAGILITY FRACTURES: A SYSTEMATIC REVIEW

Introduction: The SpineJackⓇ (SJ) system received FDA clearance in 2018, therefore this device is currently available to perform kyphoplasty in osteoporotic vertebral fractures. This study aims to assess the outcome of the SJ system in the management of vertebral fragility fractures (VFFs).

Evidence Acquisition and Synthesis: OVID-MEDLINEⓇ, EMBASE, Cochrane Library, SCOPUS, Springer Link, Web of Science, Google Scholar and PubMed were searched from January 2015 to November 2021 to identify relevant studies. The methodological qualities of the studies were evaluated, and relevant data were extracted.

Seven clinical trials, recruiting 644 patients with 690 VFFs were included. Although PVP, balloon kyphoplast (BKP) and SJ showed comparable effectiveness in back pain relief in patients with VFFs, SJ showed a faster and higher pain relief and a better quality of life, compared with the other two augmentation techniques. Moreover, patients treated with SJ, compared with PVP and BKP, showed a better vertebral body height (VBH) restoration and kyphotic correction; these findings were confirmed also at long-term follow-up. Asymptomatic cement leakage and adjacent level fractures (ALFs) were observed in patients treated with SJ, but with a lower incidence compared with PVP and BKP.

Conclusions: This systematic review shows that SJ has an excellent risk/benefit profile and is more effective than the other augmentation techniques in VBH restoration and kyphotic correction. These findings correlate with a better postoperative quality of life.

A Toolbox of Bone Consolidation for the Interventional Radiologist

Bone consolidation is increasingly used in the treatment of both benign and malignant bone conditions. Percutaneous vertebroplasty, for example, has been shown to be useful in vertebral compression fractures in the VAPOUR trial which showed its superiority to placebo for pain reduction in the treatment of acute vertebral compressive fractures. Further tools have since been developed, such as kyphoplasty, spinal implants, and even developments in bone cements itself in attempt to improve outcome, such as chemotherapy-loaded cement or cement replacements such as radio-opaque silicon polymer. More importantly, bone fixation and its combination with cement have been increasingly performed to improve outcome. Interventional radiologists must first know the tools available, before they can best plan for their patients. This review article will focus on the tool box available for the modern interventional radiologist.

Clinical Outcomes and Safety Comparison of Vertebroplasty, Balloon Kyphoplasty, and Vertebral Implant for Treatment of Vertebral Compression Fractures

BACKGROUND AND PURPOSE

Vertebral compression fracture represents a major health burden for the aging populations globally. However, limited studies exist on the relative efficacy and safety of surgical interventions for vertebral compression fracture. Here, we aim to compare clinical and patient-reported outcomes following vertebral augmentation using balloon kyphoplasty, vertebroplasty, and SpineJack vertebral implant.

MATERIALS AND METHODS

An institutional review board-approved, retrospective, multi-institutional review of patients undergoing vertebral augmentation with kyphoplasty, vertebroplasty, and/or a SpineJack vertebral implant was performed between 2018 and 2021. Primary outcomes included pre- and postprocedural pain ratings and vertebral body height restoration. The secondary outcome was a change in the local kyphotic angle. The Kruskal-Wallis test was used to compare outcomes across 3 treatment options. Complications were reviewed during and 30-90 days after the procedure.

RESULTS

Vertebral augmentation of 344 vertebral compression fracture levels was performed during the study period. Sixty-seven patients had 79 kyphoplasty procedures (55% women; mean age, 64.2 [SD, 12.3] years). Seventy-four patients underwent a mean of 84 vertebroplasty procedures (51% women; mean age, 63.5 [SD, 12.8] years), and 61 patients had a mean of 67 SpineJack vertebral implant procedures (57.4% women; mean age, 68.3 [SD, 10.6] years). Following kyphoplasty, vertebroplasty, and SpineJack vertebral implant, pain scores improved significantly (P < .001). Resting pain improvement was similar across the 3 procedures, whereas improvement of "worst pain" was significantly better following a SpineJack vertebral implant compared with kyphoplasty and vertebroplasty (P < .001). Patients with a SpineJack vertebral implant had greater improvement in vertebral body height restoration and local kyphotic angle compared with those undergoing kyphoplasty and vertebroplasty. Adjacent level fractures (6.7% incidence) occurred similarly in the 3 procedure types. There were no other peri- or postoperative complications.

CONCLUSIONS

The SpineJack vertebral implant showed equivalent pain improvement compared with vertebroplasty and kyphoplasty, but it had superior vertebral body height restoration and local kyphotic angle improvement. This study supports the SpineJack vertebral implant as a safe and effective alternative (adjunct) for vertebral augmentation, especially in patients with moderate-to-severe vertebral compression fractures for greater improvement in vertebral body height restoration.

EXPANDABLE INTRAVERTEBRAL IMPLANTS IN POST-TRAUMATIC VERTEBRAL NECROSIS - NEW CLASSIFICATION SUGGESTION

The progressive evolution of post-traumatic vertebral necrosis and consequent loss of structural integrity of the vertebral body along with neurological risk, makes it one of the most feared and unpredictable pathologies in spine traumatology. Several studies have addressed the role of vertebroplasty, kyphoplasty, and corpectomy in its treatment; however, it remains a controversial concept without a defined therapeutic algorithm. The recent emergence of expandable intravertebral implants, which allow, by a percutaneous transpedicular application, the capacity for intrasomatic filling and maintenance of the height of the vertebral body, makes them a viable option, not only in the treatment of acute vertebral fractures, but also in non-union cases. In this study, we present a review of the current evidence on the application of expandable intravertebral implants in cases of post-traumatic vertebral necrosis. Based on the available scientific literature, including previous classifications of post-traumatic necrosis, and on the mechanical characteristics of the main expandable intravertebral implants currently available, we propose a simplified classification of this pathology, considering parameters that influence surgical therapeutic guidance, the morphology and the dynamics of the necrotic vertebra's mobility. According to its stages and based on authors' experience and on the scarce literature, we propose an initial therapeutic algorithm and suggest preventive strategies for this disease, considering its main risk factors, that is, fracture comminution and impairment of vertebral vascularity. Therefore, expandable intravertebral implants have a promising role in this condition; however, large prospective studies are needed to confirm their efficacy, to clarify the indications of each of these devices, and to validate the algorithm suggestion regarding treatment and prevention of post-traumatic vertebral necrosis. Level of Evidence III, Systematic Review/Actualization.

Biomechanical evaluation of a novel minimally invasive pedicle bone cement screw applied to the treatment of Kümmel's disease in porcine vertebrae

Background and objective: Treatment of Kümmel's Disease (KD) with pure percutaneous kyphoplasty carries a greater likelihood of bone cement displacement due to hardened bone and defect of the peripheral cortex. In this study, we designed a novel minimally invasive pedicle bone cement screw and evaluate the effectiveness and safety of this modified surgical instruments in porcine vertebrae. Methods: 18 mature porcine spine specimens were obtained and soaked in 10% formaldehyde solution for 24 h. 0.5000 mmol/L EDTA-Na2 solution was used to develop in vitro osteoporosis models of porcine vertebrae. They were all made with the bone deficiency at the anterior edge of L1. These specimens were randomly divided into 3 groups for different ways of treatment: Group A: pure percutaneous kyphoplasty (PKP) group; Group B: unilateral novel minimally invasive pedicle bone cement screw fixation combined with PKP group; Group C: bilateral novel minimally invasive pedicle bone cement screw fixation combined with PKP group. The MTS multi-degree of freedom simulation test system was used for biomechanical tests, including axial loading of 500 N pressure, range of motion (ROM) in flexion, extension, left/right lateral bending, and left/right axial rotation at 5 Nm, and the displacement of bone cement mass at maximum angles of 5° and 10°. Result: The three groups were well filled with bone cement, no leakage or displacement of bone cement was observed, and the height of the vertebrae was higher than pre-operation (p < 0.05). In the left/right axial rotation, the specimens were still significantly different (p < 0.05) from the intact specimens in terms of ROM after PKP. In other directions, ROM of all group had no significant difference (p < 0.05) and was close to the intact vertebrae. Compared with PKP group, the relative displacement of bone cement in groups B and C was smaller (p < 0.05). Conclusion: In the in vitro animal vertebral models, the treatment of KD with the placement of novel pedicle minimally invasive bone cement screw combined with PKP can effectively restore the vertebral height, improve the stability of the affected vertebra and prevent the displacement of bone cement. Biomechanically, there is no significant difference between bilateral and unilateral fixation.

Percutaneous Vertebral Reconstruction (PVR) Technique of Pathological Compression Fractures: An Innovative Combined Treatment of Microwave Ablation, Bilateral Expandable Titanium SpineJack Implants Followed by Vertebroplasty

(1) Background: to retrospectively evaluate safety and efficacy of combined microwave ablation (MWA) and bilateral expandable titanium SpineJack (SJ) implants followed by vertebroplasty (VP) for the treatment of painful thoracolumbar pathological vertebral compression fracture. (2) Methods: from July 2017 to October 2022, twenty-eight patients (13 women and 15 men; mean age 68 ± 11 years) with a history of primary neoplasm and thirty-six painful vertebral metastases with vertebral compression fracture underwent combined MWA and bilateral expandable titanium SpineJack implants with vertebroplasty. We analyzed safety through complications rate, and efficacy through vertebral height restoration and pain decrease, evaluated using a visual analogue scale (VAS), and Functional Mobility Scale (FMS), and local tumor control. Contrast-enhanced CT scans were performed at 1, 3, and 6 months and a contrast-enhanced spine MRI at 6 months after the procedure. (3) Results: Technical success rate was 100%. No procedure-related major complications or death occurred. Vertebral height restoration was observed in 22 levels (58%), with a mean anterior height restoration of 2.6 mm ± 0.6 and a mean middle height restoration of 4.4 mm ± 0.6 (p < 0.001). Mean VAS score of pain evaluation on the day before treatment was 6.3 ± 1.5 (range 4-9). At the 6-month evaluation, the median VAS score for pain was 0.4 ± 0.6 (range 0-2) with a mean reduction of 93.65% (6.8 ± 0.7 vs. 0.4 ± 0.6; p < 0.000) compared with baseline evaluation. Contrast-enhanced CT scans were performed at 1, 3, and 6 months and a contrast-enhanced spine MRI was performed at 6 months after the procedure, showing no local recurrence, implant displacement, or new fractures in the treated site. (4) Conclusions: combined microwave ablation and bilateral expandable titanium SpineJack implants with vertebroplasty is a safe and effective procedure for the treatment of pathological compressive vertebral fractures. The vertebral stabilization achieved early and persistent pain relief, increasing patient mobility, improving recovery of walking capacity, and providing local tumor control.

Re-expansion of vertebral compression fractures in patients with multiple myeloma with percutaneous vertebroplasty using spinejack implants: a preliminary and retrospective study

Objective

To retrospectively evaluate the feasibility and effectiveness of vertebroplasty using Spinejack implantation for the treatment and stabilization of painful vertebral compression fractures, in patients diagnosed with Multiple Myeloma (MM), to allow both an effective pain reduction and a global structural spine stabilization.

Materials and Methods

From July 2017 and May 2022 thirty-nine patients diagnosed MM, with forty-nine vertebral compression fractures underwent percutaneous Vertebroplasty using Spinejack Implants. We analyzed the feasibility and complications of the procedure, the decrease in pain using visual analogue scale (VAS) and Functional Mobility Scale (FMS).

Results

The technical success rate was 100%. No procedure-related major complications or death occurred. In the 6-month follow-up, the mean VAS score decreased from 5.4 ± 1.0 to 0.2 ± 0.5 with a mean reduction of 96.3%. FMS decreased from 2.3 ± 0.5 vs. 1.2 ± 0.4 with a mean reduction of -47.8%. There were no major complications related to incorrect positioning of the Expandable Titanium SpineJack Implants. In five patients, a cement leak was observed with no associated clinical manifestations. The average length of hospital stay was 6-8 Hours6.6 ± 1.2 h. No new bone fractures or local disease recurrence occurred during a median contrast-enhanced CT follow-up of 6 months.

Conclusions

Our results suggest that vertebroplasty, using Spinejack implantation for the treatment and stabilization of painful vertebral compression fractures, secondary to Multiple Myeloma is a safe and effective procedure with long - term pain relief and restoration of vertebral height.

Spinal artery syndrome following kyphoplasty in the setting of a non-compressive extradural cement extravasation: a case report

INTRODUCTION

Cement extravasation (CE) during vertebroplasty or kyphoplasty for vertebral compression fracture (VCF) is not uncommon, though neurological deficits occur rarely and when paraparesis occurs severe cord compression has been described. We report a case of progressive paraparesis in the setting of non-compressive extradural CE during kyphoplasty with evidence for spinal artery syndrome and neurological recovery after treatment.

CASE PRESENTATION

A 77-year-old female with T12 VCF failed conservative treatment and underwent kyphoplasty. In the recovery room, the patient was noted to have bilateral leg weakness, left worse than right, and had urgent CT scan that showed right paracentral CE without cord compression or arterial cement embolization. The patient was transferred to a tertiary hospital and had MRI of the spine that confirmed extradural CE and no cord compression. Because the patient had progression of lower extremity deficits despite medical management, she underwent surgical decompression, cement excision, and spinal fusion with instrumentation. Post op MRI showed T2 hyperintensities in the spinal cord consistent with spinal artery syndrome. One month post op, she had almost complete recovery of her neurological function.

DISCUSSION

Spinal artery syndrome may be considered in patients with neurological deficit s/p kyphoplasty even if the extravasated cement does not compress the spinal cord and even if the deficits are worse contralateral to the cement extravasation. If spinal artery syndrome is present and medical management does not improve the deficits, surgery may be indicated even if there is no cord compression.

Innovative minimally invasive implants for osteoporosis vertebral compression fractures

With increasing population aging, osteoporosis vertebral compression fractures (OVCFs), resulting in severe back pain and functional impairment, have become progressively common. Percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) as minimally invasive procedures have revolutionized OVCFs treatment. However, PVP- and PKP-related complications, such as symptomatic cement leakage and adjacent vertebral fractures, continue to plague physicians. Consequently, progressively more implants for OVCFs have been developed recently to overcome the shortcomings of traditional procedures. Therefore, we conducted a literature review on several new implants for OVCFs, including StaXx FX, Vertebral Body Stenting, Vesselplasty, Sky Bone Expander, Kiva, Spine Jack, Osseofix, Optimesh, Jack, and V-strut. Additionally, this review highlights the individualized applications of these implants for OVCFs. Nevertheless, current clinical studies on these innovative implants remain limited. Future prospective, randomized, and controlled studies are needed to elucidate the effectiveness and indications of these new implants for OVCFs.

Anterior thoracolumbar column reconstruction with the vertebral body stent-safety and efficacy

PURPOSE

The aim of this study was to assess safety and efficacy of vertebral body stenting (VBS) by analyzing (1) radiographic outcome, (2) clinical outcome, and (3) perioperative complications in patients with vertebral compression fractures treated with VBS at minimum 6-month follow-up.

METHODS

In this retrospective cohort study, 78 patients (61 ± 14 [21-90] years; 67% female) who have received a vertebral body stent due to a traumatic, osteoporotic or metastatic thoracolumbar compression fracture at our hospital between 2012 and 2020 were included. Median follow-up was 0.9 years with a minimum follow-up of 6 months. Radiographic and clinical outcome was analyzed directly, 6 weeks, 12 weeks, 6 months postoperatively, and at last follow-up.

RESULTS

Anterior vertebral body height of all patients improved significantly by mean 6.2 ± 4.8 mm directly postoperatively (p < 0.0001) and remained at 4.3 ± 5.1 mm at last follow-up compared to preoperatively (p < 0.0001). The fracture kyphosis angle of all patients improved significantly by mean 5.8 ± 6.9 degrees directly postoperatively (p < 0.0001) and remained at mean 4.9 ± 6.9 degrees at last follow-up compared to preoperatively (p < 0.0001). The segmental kyphosis angle of all patients improved significantly by mean 7.1 ± 7.6 degrees directly postoperatively (p < 0.0001) and remained at mean 2.8 ± 7.8 degrees at last follow-up compared to preoperatively (p = 0.03). Back pain was ameliorated from a preoperative median Numeric Rating Scale value of 6.5 to 3.0 directly postoperatively and further bettered to 1.0 six months postoperatively (p = 0.0001). Revision surgery was required in one patient after 0.4 years.

CONCLUSION

Vertebral body stenting is a safe and effective treatment option for osteoporotic, traumatic and metastatic compression fractures.

Sagittal correction after short percutaneous fixation for thoracolumbar compression fractures: comparison of the combination of SpineJack® kyphoplasty and fractured vertebra screw fixation

PURPOSE

The aim of this study was to compare two percutaneous pedicle fixations for the treatment of thoracolumbar fractures: one associating a jack kyphoplasty (SpineCut) and the other using intermediate screws (Trident).

METHODS

All adult patients treated for single-level Magerl/AO type A thoracolumbar traumatic fractures in four orthopaedic departments, with SpineCut or Trident, with a one year minimum follow-up, were retrospectively included. Neurological disorders and osteoporotic fractures were not included. The following data were collected: age, sex, Magerl/AO type, type of surgery, and complications. Radiological parameters were analyzed on pre-operative CT scan, and on standing X-rays before discharge, at three months and one year post-operative: vertebral wedge angle (VWA), regional kyphosis angle (RKA), and traumatic regional angulation (TRA: difference between RKA and physiological values for each vertebra).

RESULTS

Eighty patients were included, with 42 patients in SpineCut group and 38 in Trident group. Mean age was 41 ± 15.7 years. TRA correction did not differ between the groups: respectively 11.2 ± 8.1° in SpineCut versus 10.2 ± 9.1° in Trident group (p = 0.52). TRA loss of correction between early post-operative and three months was statistically higher in Trident group: -4 ± 5.1° versus -1.5 ± 3.8° (p = 0.03). After 3 months, TRA correction loss was comparable between the groups. Multivariate analysis demonstrated that pre-operative VWA was the only factor significantly associated with early TRA correction loss (p = 0.01). VWA correction and loss of correction did not differ significantly between the groups. No complications were observed.

CONCLUSION

Percutaneous pedicle fixations of traumatic thoracolumbar fractures associating jack kyphoplasty and intermediate screws are both safe and efficient techniques.

Biomechanical evaluation of a novel tri-blade titanium implantable vertebral augmentation device

BACKGROUND CONTEXT

Titanium implantable vertebral augmentation device (TIVAD) are regarded as having potential in the treatment of vertebral compression fractures (VCFs). However, improper design in current TIVADs results in the inability to effectively restore VCF height and maintain stability. There is still an unmet clinical need for improvement.

PURPOSE

The authors tested a newly developed a TIVAD (Tri-blade fixed system) that can provide enough endplate collapse support to restore the vertebral body height in a safe retraction mechanism for VCFs using minimally invasive surgery (MIS).

STUDY DESIGN

The performed biomechanical tests included blade expansion force, lifetime of cement embedded and vertebral height restoration efficiency of porcine osteoporosis VCFs for its feasibility.

METHODS

A cylinder with 3 surface cuts that form blades that can be expanded into a conical space was designed (Tri-blade fixed system). The 3 blades can be expanded outward with angles between blades as 105°/ 105°/150° for lower left/lower right/upper arms, respectively that reach 15mm in height and 14.8 mm in width. A frame was specifically designed to measure the contact force using force sensing resistors during blade expansion. The Tri-blade fixed system was embedded into a cement block to perform fatigue testing under 2000N pressure (5*10⁶ cycles) for understanding the device lifetime limitation. The Tri-blade system was then inserted into porcine osteoporosis VCFs to examine the vertebral height restoration efficiency.

RESULTS

The average maximum contact force for the top, bottom left and right blades were 299.0N, 283.5N and 279.3N, respectively with uniformly outward expansion forces. The fatigue test found that there were no obvious cracks or damage to the cement block. The porcine osteoporosis vertebral body at the anterior, middle, and posterior heights can be restored to 21.9%, 12.6% and 6.4%, respectively.

CONCLUSIONS

This study developed a novel TIVAD with conical shape that can provide a more stable structure with sufficient/uniform expansion force, passing the fatigue test with bone cement and high effective in vertebral height restoration tests for porcine osteoporosis VCFs.

CLINICAL SIGNIFICANCE

The new 3D Tri-blade TIVAD may offer a new treatment option for VCFs.

Implant removal after short percutaneous pedicle fixation associated with SpineJack® kyphoplasty: is correction sustained?

PURPOSE

This study objective was to evaluate sagittal correction loss after instrumentation removal in patients treated for thoracic or lumbar compression fractures treated with SpineJack^® kyphoplasty associated with short percutaneous pedicle screw fixation.

METHODS

This retrospective multicenter study was carried out in three major French trauma centers. All patients with a single type A thoracic or lumbar fracture, treated by the studied technique between 2017 and 2020, have been included. Demographic data, fracture type, removal procedure achievement and term were collected. Radiological parameters were measured at five timepoints: pre-operative, intra-operative, immediate post-operative, early post-operative (< 3 months) and at follow-up (1 year). Vertebral wedge angle (angle between the two endplates of the fractured vertebra) and traumatic regional angulation (TRA-calculated by subtracting regional kyphosis from the physiological reference values).

RESULTS

150 patients were included. Mean age was 48.6 ± 17.8 years. Average follow-up was 14.4 ± 3 months. 82 patients had secondary instrumentation removal. Mean time to removal was 6.4 ± 2.4 months. TRA correction loss between immediate post-operative and last follow-up was greater in removal group: 5.1 ± 5.6° versus 2.7 ± 4.7° (p = 0.01). Material was removed earlier in younger patients (p = 0.002). TRA correction loss was similar in the early and late removal groups (p = 0.83). Multivariate analysis identified only Magerl/AO A3 fractures as risk factor for loss of TRA correction (p = 0.007).

CONCLUSION

Instrumentation removal was associated with good radiological outcomes with a non-significant loss of vertebral wedge angle and tolerable loss of traumatic regional angulation (+ 2.4° compared to the no-removal group), even if performed early.

"Double Cross Sign" Could Be an Indicator of an Adequate Amount of Bone Cement in Kyphoplasty with the SpineJack System: A Retrospective Study

Kyphoplasty with the SpineJack system was able to restore vertebral height and stabilize the vertebra with an injection of bone cement. The goal of this study was to seek a reliable assessing method during the surgery in determining the minimum amount of bone cement required for the SpineJack system to restore vertebral height and stabilize the vertebra. We defined the “double cross sign” as bone cement that expanded vertically along the bilateral SpineJack system, and spread across the midline of the vertebral body as viewed in the anteroposterior (AP) view of the radiographic image. Sixty-five patients aged 74.5 ± 8.5 years with vertebral compression fracture were included in the study. Patients with a positive double cross sign had better ODI score than those without the double cross sign (20.0 ± 6.9 vs. 32.3 ± 8.2; p < 0.001). Postoperative regional kyphotic and local kyphotic angle were significantly better in the positive double cross sign group (11 ± 8.8 degrees vs. 5.3 ± 3.2 degrees; p = 0.001/11.7 ± 6.2 degrees vs. 6.6 ± 4.1 degrees; p = 0.001, respectively). The more stable construct was built once the double cross sign was achieved during surgery. In this study, a convenient and intuitive method in identifying the minimum but sufficient quantity of injected cement during the SpineJack procedure was developed.

Height restoration and sustainability using bilateral vertebral augmentation systems for vertebral compression fractures: a cadaveric study

BACKGROUND CONTEXT

The treatment of vertebral compression fractures using percutaneous augmentation is an effective method to reduce pain and decrease mortality rates. Surgical methods include vertebroplasty, kyphoplasty, and vertebral augmentation with implants. A previous study suggested that a titanium implantable vertebral augmentation device (TIVAD) produced superior height restoration compared to balloon kyphoplasty (BKP) but was based on a less clinically relevant biomechanical model. Moreover, the introduction of high pressure balloons and directional instruments may further aid in restoring height.

PURPOSE

The objective was to evaluate three procedures (BKP, BKP w/ Kyphon Assist (KA; directional instruments), and TIVAD) used for percutaneous augmentation of vertebral fractures with respect to height restoration and sustainability post-operatively.

STUDY DESIGN/SETTING

This is an in vitro cadaver study performed in a laboratory setting.

METHODS

Five osteoporotic female human cadaver thoracolumbar spines (age: 63-77 years, T-score: -2.5 to -3.5, levels: T7-S1) were scanned using computed tomography and dissected into 30 two-functional spine units (2FSUs). Vertebral wedge compression fractures were created by reducing the anterior height of the vertebrae by 25% and holding the maximum displacement for 15 minutes. Post-fracture, surgery was performed on each 2FSU with a constant 100 N load. Surgeries included BKP, BKP w/ KA, or TIVAD (n=10 per treatment group). Post-surgery, cyclic loading was performed on each 2FSU for 10,000 cycles at 600 N (walking), followed by 5,000 cycles at 850 N (standing up/sitting down), and 5,000 cycles at 1250 N (lifting a 5-10kg weight from the floor). Fluoroscopic images were taken and analyzed at the initial, post-fracture, post-surgery, and post-loading timepoints. Anterior, central, and posterior heights, Beck Index, and angle between endplates were assessed.

RESULTS

No difference in height restoration was observed among treatment groups (p=.72). Compared to the initial height, post-surgery anterior height was 96.3±8.7% for BKP, 94.0±10.0% for BKP w/ KA, and 95.3±5.8% for TIVAD. No difference in height sustainability in response to 600 N (p=.76) and 850 N (p=.20) load levels was observed among treatment groups. However, after 1250 N loading, anterior height decreased to 93.8±6.8% of the post-surgery height for BKP, 95.9±6.4% for BKP w/ KA, and 86.0±6.6% for TIVAD (p=.02). Specifically, the mean anterior height reduction between post-surgery and post-1250 N loading timepoints was lower for BKP w/ KA compared to TIVAD (p=.02), but not when comparing BKP to TIVAD (p=.07). No difference in Beck Index or angle between endplates was observed at any timepoint among the treatment groups.

CONCLUSIONS

The present study, utilizing a clinically relevant biomechanical model, demonstrated equivalent height restoration post-surgery and at relatively lower-level cyclic loading using BKP, BKP w/ KA, and TIVAD, contrary to results from a previous study. Less anterior height reduction in response to high-level cyclic loading was observed in the BKP w/ KA group compared to TIVAD.

CLINICAL SIGNIFICANCE

All three treatments can restore height similarly after a vertebral compression fracture, which may lead to pain reduction and decreased mortality. BKP w/ KA may exhibit less height loss in higher-demand patients who engage in physical activities that involve increased weight resistance.

Is vertebral stenting kyphoplasty a good choice in the treatment of osteoporotic vertebral fracture? A series of 47 patients (v2)

Background

The incidence of vertebral fragility fracture is increasing over last three decades with an essential impact on quality of life. Some devices were proposed to improve conventional kyphoplasty in the last five years, known as vertebral stenting kyphoplasty (VSK).

Materials and Methods

All osteoporotic vertebral fractures (OVF) treated with VSK, single-level fracture without neurological impairment, and with more than 24 months of follow-up were included in the study. We recorded fracture types according to DGOU classification, fracture level, regional kyphosis angle (RKA), Oswestry disability index (ODI), and complications.

Results

Forty-seven consecutive patients were included. RKA significantly improved from pre to postoperative values (p<0.000001) and to follow-up values (p<0.00001). A significant difference was found between preoperative RKA of (OF2+OF3) and OF4 (p<0.00001), confirmed immediately after surgery (p= 0.005425) and at last follow up (p= 0.000947). A significant difference was found in correction of RKA between (OF2+OF3) and OF4 at injury time and after treatment (p<0.00001), and it was confirmed at the last follow-up (p=0.000026). ODI showed a significant difference between (OF2+OF3) and OF4 type of fractures (p=0.038216). We recorded five complications: 2 cases of leakage without neurological impairment, two progressions of kyphosis, and one implant migration.

Conclusions

VSK is an excellent and reliable option in the treatment of OVF, with good clinical results and preservation of obtained RKA at the time of treatment. However, in case of vertebral collapse with the involvement of both vertebral plates, surgeons must be aware of possible implant failure or migration.

Level of Evidence

4.

Robot-Assisted Versus Fluoroscopy-Assisted Kyphoplasty in the Treatment of Osteoporotic Vertebral Compression Fracture: A Retrospective Study

STUDY DESIGN

A retrospective study.

OBJECTIVES

To compare the clinical and radiological outcomes of robot assisted (RA) and fluoroscopy assisted (FA) percutaneous kyphoplasty (PKP) in treating single/double segment osteoporotic vertebral compression fracture (OVCF).

METHODS

Patients with single/double segment OVCF receiving either RA or FA PKP were evaluated retrospectively at our spine center from April 2018 to October 2019. The operation time, fluoroscopy frequency, fluoroscopy exposure time, total radiation dose, visual analogue scale (VAS), local kyphosis angle (LKA), height of fractured vertebra (HFV) and complications were compared between the single/double RA group and the FA group.

RESULTS

A total of 96 cases were included in this study, with 59 cases of single segment OVCF and 37 cases of double segment OVCF. For single/double segment OVCF, both RA and FA PKP could relieve pain and reduce fracture. The RA group showed lower fluoroscopy frequency, shorter fluoroscopy exposure time during operation for surgeons, better correction in LKA and HFV, lower rate of cement leakage, but more fluoroscopy frequency, fluoroscopy exposure time and radiation dose for patients compared with the FA group (P < 0.05), while the single RA group showed longer operation time compared with the FA group (P < 0.05).

CONCLUSIONS

For single/double segment OVCF, RA has more advantages in correcting vertebra fracture, reducing intraoperative radiation exposure for surgeons, and reducing the cement leakage rate, but it increases intraoperative radiation for patients compared with FA PKP. And FA has shorter operation time in treating single segment OVCF than RA PKP.

Therapeutic Efficacy of Third-Generation Percutaneous Vertebral Augmentation System (PVAS) in Osteoporotic Vertebral Compression Fractures (OVCFs): A Systematic Review and Meta-analysis

Purpose

This study aimed to assess whether the third-generation PVAS was superior to percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) in treating patients with OVCFs.

Methods

Databases, including Pubmed, Embase, and Cochrane library, were searched to identify relevant interventional and observational articles in vivo or in vitro comparing the third-generation PVAS to PVP/PKP in OVCFs patients. A meta-analysis was performed under the guidelines of the Cochrane Reviewer's Handbook.

Results

11 in vivo articles involving 1035 patients with 1320 segments of diseased vertebral bodies and 8 in vitro studies enrolling 40 specimens with 202 vertebral bodies were identified. The vivo studies indicated no significant differences were found in visual analog scale (VAS), Oswestry Disability Index (ODI), operation time, or injected cement volume (P > 0.05). The third-generation PVAS was associated with significant improvement in vertebral height and Cobb angle (P < 0.05) and also with a significantly lower risk of cement leakages and new fractures (P < 0.05). The vitro studies suggest that the third-generation PVAS was associated with better anterior vertebral height (AVH) and kyphotic angle (KA) after deflation and cement. No significant differences were found in stiffness or failure load after cement between the two groups (P > 0.05).

Conclusion

Based on current evidence, although providing similar improvement in VAS and ODI, the third-generation PVAS may be superior to PVP/PKP in local kyphosis correction, vertebral height maintenance, and adverse events reduction. Further high-quality randomized studies are required to confirm these results.

Numerical Comparison of Restored Vertebral Body Height after Incomplete Burst Fracture of the Lumbar Spine

BACKGROUND AND OBJECTIVES

Vertebral compression fracture is a major health care problem worldwide due to its direct and indirect negative influence on health-related quality of life and increased health care costs. Although a percutaneous surgical intervention with balloon kyphoplasty or metal expansion, the SpineJack, along with bone cement augmentation has been shown to efficiently restore and fix the lost vertebral height, 21-30% vertebral body height loss has been reported in the literature. Furthermore, the effect of the augmentation approaches and the loss of body height on the biomechanical responses in physiological activities remains unclear. Hence, this study aimed to compare the mechanical behavior of the fractured lumbar spine with different restored body heights, augmentation approaches, and posterior fixation after kyphoplasty using the finite element method. Furthermore, different augmentation approaches with bone cement and bone cement along with the SpineJack were also considered in the simulation.

MATERIALS AND METHODS

A numerical lumbar model with an incomplete burst fracture at L3 was used in this study. Two different degrees of restored body height, namely complete and incomplete restorations, after kyphoplasty were investigated. Furthermore, two different augmentation approaches of the fractured vertebral body with bone cement and SpineJack along with bone cement were considered. A posterior instrument (PI) was also used in this study. Physiological loadings with 400 N + 10 Nm in four directions, namely flexion, extension, lateral bending, and axial rotation, were applied to the lumbar spine with different augmentation approaches for comparison.

RESULTS

The results indicated that both the bone cement and bone cement along with the SpineJack could support the fractured vertebral body to react similarly with an intact lumbar spine under identical loadings. When the fractured body height was incompletely restored, the peak stress in the L2-L3 disk above the fractured vertebral body increased by 154% (from 0.93 to 2.37 MPa) and 116% (from 0.18 to 0.39 MPa), respectively, in the annular ground substance and nucleus when compared with the intact one. The use of the PI could reduce the range of motion and facet joint force at the implanted levels but increase the facet joint force at the upper level of the PI.

CONCLUSIONS

In the present study, complete restoration of the body height, as possible in kyphoplasty, is suggested for the management of lumbar vertebral fractures.

INTRAVERTEBRAL EXPANDABLE IMPLANTS IN THORACOLUMBAR VERTEBRAL COMPRESSION FRACTURES

Current scientific evidence enhances the importance of the anatomic restauration of vertebral bodies with compression fractures aiming, as with other human body joints, to obtain a biomechanic and functional spine as close as the one prior to the fracture as possible. We consider that anatomic reduction of these fractures is only completely possible using intravertebral expandable implants, restoring vertebral endplate morphology, and enabling a more adequate intervertebral disc healing. This enables avoiding disc and osteodegenerative changes to that vertebral segment and its adjacent levels, as well as the anterior overload of adjacent vertebral bodies in older adults - a consequence of post-traumatic vertebral flattening - thus minimizing the risk of adjacent vertebral fractures. The ability of vertebral body fracture reduction and height maintenance over time and its percutaneous transpedicular application make the intra-vertebral expandable implants a very attractive option for treating these fractures. The authors show the direct and indirect reduction concepts of vertebral fractures, review the biomechanics, characteristics and indications of intravertebral expandable implants and present a suggestion for updating the algorithm for the surgical treatment of vertebral compression fractures which includes the use of intravertebral expandable implants. Level of Evidence V, Expert Opinion.

Does intraoperative 3D navigation improve SpineJack vertebral augmentation in thoracic and lumbar compression fracture?

INTRODUCTION

The aim of this retrospective study was to evaluate the effect of navigation on the positioning of the SpineJack implant in the treatment of thoracic and lumbar compression fractures.

METHODS

Between January 2018 and December 2019, all patients operated on for thoracic or lumbar fracture using the SpineJack device in stand-alone were included in this single-center study. The positioning of the SpineJack implant was analyzed on axial CT views by measuring the angle between the axis of the pedicle and the axis of the final implant. The relationships between implant positioning and the use of navigation or fluoroscopy, pedicle dimensions and levels of injury were analyzed. Surgical time, radiation exposure, radiological findings and complications were assessed.

RESULTS

One hundred patients were included, for 103 fractured vertebrae and a total of 205 implants, 148 placed under standard fluoroscopy and 57 with the Surgivisio navigation system. For pedicle diameters≥5mm (165 implants), the positioning of the implant relative to the axis of the pedicle was significantly better in the navigation group: 2°±1.4° (range, 0-7°) in the fluoroscopy group versus 1.2°±1.1° (range, 0-5°) in the navigation group (p=0.04). There were no significant differences in reduction of vertebral kyphosis angle or mean operating time. Dose area product (DAP) was significantly higher with navigation: 4.43Gy.cm² versus 0.47Gy.cm² (p<0.001) and dose to the surgeon significantly lower: 0.5 versus 1.6μSv (p<0.001). No difference was found regarding complications. Subgroup analysis showed significantly greater operative time and patient irradiation in the fluoroscopy group when pedicle diameter was less than 5mm.

CONCLUSION

This study demonstrates the interest of navigation for positioning the SpineJack implant with respect to the pedicle axis in vertebrae with pedicle diameter≥5mm. This study also confirmed the reliability of navigation and lower radiation dose to the surgeon, regardless of the fracture level. Navigation reduced operating time and patient irradiation for vertebrae with pedicle diameter<5mm.

LEVEL OF EVIDENCE

IV; retrospective study.

Expandable Intravertebral Implants: A Narrative Review on the Concept, Biomechanics, and Outcomes in Traumatology

Expandable intravertebral implants are self-expanding devices applied percutaneously by the posterior transpedicular approach. These devices introduce the concept of anatomical restoration of vertebral body endplates and direct anatomical reduction performed from the interior of the vertebral body with a compression fracture. This paper aims to provide a narrative review on the concept, indications, biomechanical characteristics, as well as functional and radiographic outcomes of the main expandable intravertebral implants currently available, in terms of their application to thoracolumbar spine traumatology. To this end, we performed a search in July 2021 on the MEDLINE/PubMed platform with the words "expandable intravertebral implant", "armed kyphoplasty", "Vertebral Body Stenting" or "stentoplasty" and "SpineJack". The search yielded 144 papers, and of those, we included 15 in this review. We concluded that percutaneous transpedicular posterior access, the ability to reduce vertebral body fractures, particularly of the vertebral endplates and to maintain the vertebral body height, makes the application of expandable intravertebral implants an attractive option in the treatment of thoracolumbar vertebral compression fractures. However, more prospective, randomized, and large-scale blinded studies are still warranted, especially comparative studies between treatments and about the preferential use of an expansive implant over others, in order to gain definitive insights into the effectiveness and indications of each of these devices.

Use of the SpineJack direct reduction for treating type A2, A3 and A4 fractures of the thoracolumbar spine: a retrospective case series

BACKGROUND

Compression injuries of the thoracolumbar spine without neurological impairment are usually treated with minimally invasive procedures. Intravertebral expandable implants represent an alternative strategy in fractures with low fragments' displacement.

METHODS

Patients with A2, A3 and A4 fractures of the T10-L2 spinal segment without neurological impairment, fracture gap >2 mm, vertebra plana, pedicle rupture, pedicle diameter <6 mm, spinal canal encroachment ≥50%, and vertebral body spread >30% were treated with the SpineJack device. Patients with pathological/osteoporotic fractures were excluded. Demographic and fracture-related data were assessed together with vertebral kyphosis correction, vertebral height restoration/loss of correction and final kyphosis. The modified Rankin Scale (mRS), Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), Smiley-Webster Pain Scale (SWPS) and EuroQol-5D (EQ-5D) were evaluated at 1 (-post), 6 and 12 months (-fup) after surgery. Statistical analysis was performed and p values ≤0.05 were considered significant.

RESULTS

Fifty-seven patients were included in the study. Patients aged >60 years reported worse kyphosis correction (<4°) with more postoperative complications, while vertebral plasticity in younger patients, fragmentation-related greater remodeling in A3/A4 fractures, and treatments within 7 days of trauma determined superior wedging corrections, with better EQ-5D-post and mRS-fup. Cement leakages did not affect functional outcome, while female gender and American Society of Anesthesiologists (ASA) score of 3-4 were associated with worse ODI-fup and VAS-fup. Although fracture characteristics and radiological outcome did not negatively influence the clinical outcome, A2 fracture was a risk factor for complications, thus indirectly compromising both the functional and radiological outcome.

CONCLUSION

With spread of <30%, the SpineJack is an alternative to minimally invasive fixations for treating A3/A4 thoracolumbar fractures, being able to preserve healthy motion segments in younger patients and provide an ultra-conservative procedure for elderly and fragile patients.

Is Kummell's Disease a Misdiagnosed and/or an Underreported Complication of Osteoporotic Vertebral Compression Fractures? A Pattern of the Condition and Available Treatment Modalities

This narrative review provides the outcomes of minimally invasive surgery (MIS) and describes the available conservative treatment options for patients with osteoporotic vertebral compression fractures (OVCFs) that have risk factors for Kummell's disease (KD). It aims to explore the evidence, emphasize the possible therapy complications, and aims to propose the most efficient clinical strategies for maintaining a good overall condition of individuals who may suffer from neurological deficits from a late-diagnosed OVCF complication. The secondary objective is to sum up the diagnostic particularities concerning individuals prone to OVCFs and KD, as the major risk factor for developing these severe conditions remains osteoporosis. Findings of our narrative review are based on the results found in PubMed, Embase, and Google Scholar from the beginning of their inception to December 2020, described independently by two authors. All of the studies included in the review focus on reporting the following treatment methods: conservative methods, vertebroplasty, kyphoplasty, targeted percutaneous vertebroplasty, frontal and side-opening cannula vertebroplasty, SpineJack, bone-feeling mesh container treatment, and the difference in the cement viscosity used (high vs. low) and the approach used (unilateral vs. bilateral). The comparison of randomized control trials (RCTs) as well as prospective and retrospective case series showed a comparable efficacy of kyphoplasty and vertebroplasty, and described cement-augmented screw fixation and the SpineJack system as effective and safe. Although it should be noted that several studies revealed inconsistent results in regards to the efficacy of using back braces and analgesics in patients who had vertebral fractures that were overlooked or not enrolled in any active surveillance program to track the patient's deterioration immediately. Nevertheless there are non-standardized guidelines for treating patients with OVCFs and their complications already established. Using these guidelines, a treatment plan can be planned that takes into consideration the patients' comorbidities and susceptibilities. However, the primary approach remains the management of osteoporosis and that is why prophylaxis and prevention play a crucial role. These measures reduce the risk of disease progression. Unfortunately, in the majority of cases these measures are not taken into account and KD develops.

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.

Advances in Vertebral Augmentation Systems for Osteoporotic Vertebral Compression Fractures

Osteoporotic vertebral compression fracture (OVCF) is a common cause of pain and disability and is steadily increasing due to the growth of the elderly population. To date, percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) are almost universally accepted as appropriate vertebral augmentation procedures for OVCFs. There are many advantages of vertebral augmentation, such as short surgical time, performance under local anaesthesia, and rapid pain relief. However, there are certain issues regarding the utilization of these vertebral augmentations, such as loss of vertebral height, cement leakage, and adjacent vertebral refracture. Hence, the treatment for OVCF has changed in recent years. Satisfactory clinical results have been obtained worldwide after application of the OsseoFix System, the SpineJack System, radiofrequency kyphoplasty of the vertebral body, and the Kiva VCF treatment system. The following review discusses the development of the current techniques used for vertebral augmentation.

Comparison Between 7 Osteoporotic Vertebral Compression Fractures Treatments: Systematic Review and Network Meta-analysis

BACKGROUND

Vertebroplasty (VP), kyphoplasty (KP), SpineJack system (SJ), radiofrequency kyphoplasty (RFK), Kiva system (Kiva), Sky kyphoplasty system (SK), and conservative treatment are widely used in the treatment of osteoporotic vertebral compression fractures (OVCFs). However, it is still unknown which is the best intervention. The aim of the current study was to evaluate the effectiveness and safety of VP, KP, SJ, RFK, Kiva, SK, and CT in the treatment of OVCFs.

METHODS

Randomized controlled trials and cohort studies comparing VP, KP, SJ, RFK, Kiva, SK, or CT for the treatment of OVCFs were identified on the basis of databases including PubMed, the Cochrane Library, Web of Science, and Springer Link. A network meta-analysis was performed using STATA 15.1.

RESULTS

A total of 56 studies with 6974 patients and 7 interventions were included in this study. The results of the surface under the cumulative probability demonstrated that SK was the best intervention in decreasing VAS scores and recovering middle vertebral height, RFK was the best intervention in improving ODI scores and decreasing incidence of new fractures, SJ was the best intervention to restore kyphosis angle, and Kiva was the best intervention to reduce incidence of bone cement leakage. Cluster analysis showed that SK was the preferable intervention on the basis of the outcomes of VAS, ODI, middle vertebral height, and kyphotic angle, and RFK was the preferable treatment in decreasing the incidence of adverse events. In our network meta-analysis, node-splitting analysis and loop inconsistency analysis showed no significant inconsistencies.

CONCLUSIONS

SK may be the most effective treatment in relieving pain, improving the quality of life, and recovering vertebral body height and kyphotic angle, while RFK may be the safest intervention for OVCFs. However, considering the limitations of this study, more high-quality trials are needed in the future to confirm the current conclusion.

Percutaneous intervertebral bridging cementoplasty for adjacent multilevel osteoporotic thoracolumbar fractures with vertebral endplate-disc complex injury: technical note

This paper describes a minimally invasive technique of percutaneous intervertebral bridging cementoplasty (PIBC) to augment the fractured vertebrae and immobilize the intervertebral space with endplate-disc complex injury simultaneously. Thirty-two patients with adjacent multilevel osteoporotic thoracolumbar fractures (AMOTLFs) and vertebral endplate-disc complex injury (EDCI) treated by PIBC were retrospectively reviewed. The PIBC technique was a combination of puncture, balloon expansion and bridging cementoplasty. The clinical and radiological assessments were reviewed. The operation time was 82.8 ± 32.5 min, and blood loss was 76.9 ± 31.7 mL. A cement bridge was connected between the two fractured vertebrae across the injured intervertebral space. VAS at three time points including pre-operation, post-operation 1 day and final follow-up was 6.9 ± 0.9, 2.9 ± 0.8 and 1.7 ± 0.8, respectively; ODI at three time points was (71.1 ± 7.8)%, (18.4 ± 5.7)%, and (10.3 ± 5.7)%, respectively; Cobb angle at three time points was 46.0° ± 10.4°, 25.9° ± 8.5°, and 27.5° ± 7.1°, respectively. Compared with pre-operation, VAS, ODI and Cobb angle were significantly improved at post-operation 1 day and final follow-up (P < 0.05). Clinical asymptomatic cement leakage was observed in thirteen patients. No vessel or neurological injury was observed. PIBC may be an alternative way of treatment for AMOTLFs with EDCI. The technique is a minimally invasive surgery to augment the fractured vertebrae and immobilize the injured intervertebral space simultaneously.

Vertebral Compression Fractures: Evaluation and Management

Painful vertebral body compression fractures are prevalent in elderly patients. Two-thirds of patients will have spontaneous resolution of pain in 4 to 6 weeks and initial management is nonoperative with pain management and bracing. A focused history and exam can identify patients likely to benefit from vertebral body augmentation (e.g., vertebroplasty or kyphoplasty). Patients with persistent back pain and bone marrow edema on magnetic resonance imaging may benefit from injection of cement into the fractured vertebral body with either vertebroplasty or kyphoplasty. Patients most likely to benefit are those with severe pain refractory to nonoperative management who are offered intervention within 3 weeks. The procedure is usually performed as an outpatient with rare complications. Most patients report immediate, durable pain relief.

Safety of vertebral augmentation with cranio-caudal expansion implants in vertebral compression fractures with posterior wall protrusion

OBJECTIVES

Vertebral augmentation (VA) has become routinely used in vertebral compression fractures (VCFs). VCFs are often associated with posterior wall protrusions (PWPs), which theoretically contraindicates vertebroplasty due to a higher risk of neurological complications. The latest generation of VA devices uses intravertebral cranio-caudal expandable implants to improve the correction of structural deformities but could also be used to prevent further PWP during cement injection. The aim of this study was to evaluate the safety of VA with expandable implant for VCFs with PWP.

METHODS

All consecutive patients treated with expandable implants were considered eligible for inclusion if they met the following criteria: (1) non-neurological VCF, (2) considered unstable (A3-A4 in AOSpine classification), (3) significant PWP (> 2 mm), (4) back pain with a visual analogue scale (VAS) ≥ 4. PWPs were independently measured by two investigators; Pearson's statistics were used for interobserver reproducibility.

RESULTS

Fifty-one consecutive patients, with a mean age of 75 ± 8.3 years (range, 50-92), were included. There was a slight decrease between mean preoperative (6.7 mm ± 2.2 mm) and postoperative (6.5 mm ± 2.2 mm) PWP (p = 0.02), with an excellent interobserver reproducibility (Pearson correlation coefficient = 0.92). A mean kyphosis reduction of 34.9% (± 28.4) was observed (p < 0.001). Forty-two patients (82.4%) had significant pain improvements (mean preoperative VAS = 6.9 [± 1.7] versus 3.1 [± 2.0] postoperatively [p < 0.001]). Secondary adjacent level fractures were noted in 16 patients (31.4%), with a reduction of that risk down to 18.8% if a preventive adjacent vertebroplasty was performed, without reaching the significance threshold (p = 0.14).

CONCLUSIONS

VA with expandable implants appeared safe for non-neurological VCFs with PWP, while allowing satisfactory pain relief.

KEY POINTS

• Vertebral augmentation with cranio-caudal expandable implants is safe for non-neurological vertebral compression fractures with posterior wall protrusions. • Vertebral augmentation with cranio-caudal expandable implants might increase the occurrence of secondary adjacent level fractures. • Adjacent level vertebroplasty might be helpful to prevent secondary adjacent level fractures.

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.

Treatment of a High-risk Thoracolumbar Compression Fracture Using Bilateral Expandable Titanium SpineJack Implants

In this case, an 80-year-old active patient developed an acute osteoporotic fracture after a fall at L1 above a previous interlaminar implant at L4-5 for stenosis with neurogenic claudication. Radiologic studies found both intra-discal and intra-vertebral vacuum clefts that are highly correlated with instability and progressive kyphosis. Long-term experience with kyphoplasty has shown that acute and subacute fractures can often be re-expanded; however, over three months to one year, the correction is frequently lost and the vertebral height continues to decrease leading to increased risk of both continued deformity and especially adjacent level fractures. The use of newly available titanium intra-vertebral implants combined with bone cement restores and maintains vertebral height and correction of deformities. Long-term studies also demonstrate a reduced risk of adjacent level fractures compared to balloon kyphoplasty. Using vertebral body implants that remain in place within the fractured vertebral body the initial height correction can be better maintained leading to less adjacent level fractures.

Re-expansion of Osteoporotic Compression Fractures Using Bilateral SpineJack Implants: Early Clinical Experience and Biomechanical Considerations

Thoraco-lumbar osteoporotic compression fractures have a higher incidence of continued collapse with development of deformity and progression to vertebra plana when untreated and even after vertebral augmentation (VA) or balloon kyphoplasty (BKP). Even when there is the restoration of height and improvement in angulation, multiple long-term follow-up series have repeatedly documented that over time, many patients lose the initial height correction and in a smaller group the vertebral body re-collapses leading to the development of progressive deformity with an increased risk for adjacent level fractures. At first, larger balloons and more cement were used to try and avoid these problems, but it did not reduce the risk of adjacent fractures. Several procedures were developed to place various types of intervertebral implants combined with bone cement to maintain the initial height correction. Initial studies with these implants showed a reduction in adjacent level fractures but the systems did not proceed to market. The SpineJack^R (SJ) system (Stryker Corp, Kalamazoo, MI), consisting of bilateral expandable titanium implants supplemented with bone cement, was first used approximately 10 years ago in Europe and recently gained FDA approval in the United States. This system provides more symmetric and balanced lateral and anterior support and is effective with lesser amounts of bone cement compared to BKP. Follow-up studies have documented that there is equal or better pain control, with better long-term results based both on maintaining vertebral height restoration and deformity correction. Most importantly, statistically it clearly reduces the risk of adjacent level fractures by at least 60%. The biomechanical effects of intravertebral implants for osteoporotic fractures in regard to the risk of adjacent level fractures and preliminary experience with the use of the SJ is reviewed.