Association Between Spinopelvic Parameters and Intravertebral Cleft in Osteoporosis Vertebral Compression Fractures

BACKGROUND

The high incidence of nonunion in osteoporosis vertebral compression fractures (OVCFs) among the elderly population is a significant concern. But the hypothesis about etiopathogenesis of the intravertebral cleft (IVC) is not convincing. This study aims to investigate the association between spinopelvic parameters and IVC.

METHODS

Patients with single segment IVC or healed vertebral compression fracture (HVCF) were retrospectively recruited for the study. Patients with IVC were assigned to the IVC group, the others were assigned to the HVCF group. We estimated whether IVC or HVCF locates the vertebra inflection point on lumbar lateral radiography. Distance between the sagittal line passing through the anterosuperior corner of S1and the center of the vertebra of healed fracture or with IVC (DSVA) and sacral slope (SS) were measured on lumbar lateral plain films. Intergroup spinopelvic parameters were analyzed. analysis to identify independent variables associated with IVC incidence. The receiver operating characteristics (ROC) curve was generated to identify the optimal cut-off point for statistically significant variables.

RESULTS

Sixty-five patients were included in the study. Thirty patients (mean age: 74 ± 7.16 years) had single-level IVC, and 35 patients (mean age: 67.71 ± 7.30 years) had single-level HVCF. Age, body mass index (BMI), and DSVA were statistically different between the groups (all P < 0.05). The occurrence of IVC was related to the DSVA in the multivariate logistic regression analysis (OR = 0.73, P < 0.05).

CONCLUSIONS

According to the results of this study, large DSVA was a risk factor for IVC formation in patients with OVCFs. Patients with global spinal malalignment should be actively observed during conservative treatment.

Does segmental artery occlusion cause intravertebral cleft following osteoporotic vertebral fracture: a prospective magnetic resonance angiography study

Background

The avascular necrosis (AVN) hypothesis of intravertebral cleft (IVC) formation in osteoporotic vertebral fracture (OVCF) has received increasing attention. The aim of this article is to detect whether the segmental artery occlusion causes the IVC following OVCF.

Methods

Between December 2019 and April 2020, 44 OVCF patients with 46 fracture levels were prospectively enrolled and the vertebral segmental arteries were evaluated by magnetic resonance angiography (MRA). The artery conditions were divided into patent, narrow and occluded. The lesion segmental occlusion rate (LSOR) and the total occlusion rate (TOR) were calculated. The association of segmental artery occlusion and IVC formation was assessed.

Results

LOSR was 15.34% and TOR was 15.12%. The segmental arteries of the unfractured vertebrae had a higher occlusion rate at thoracolumbar levels than at non-thoracolumbar levels. There was no significant difference between the IVC group and the non-IVC group in the fractured levels artery occlusion rate (20.24 ± 28.08 vs 9.78 ± 19.56, P = 0.156) or the total segmental arteries occlusion rate (13.83 ± 12.04 vs 11.57 ± 9.25, P = 0.476).

Conclusions

In patients with vertebral osteoporotic fracture, segmental artery occlusion is not associated with the development of intravertebral cleft.

The impact of intravertebral cleft on cement leakage in percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a case-control study

Background

The impact of intravertebral cleft (IVC) on cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs) has been discussed. However, the results were conflicting, as the study population and cement leakage classification were heterogeneous. The aim of the study was to evaluate the impact of IVC on the incidence of leakage through vein, leakage through cortex as well as general leakage in PVP for OVCFs.

Methods

All patients with OVCFs who underwent PVP between January 2016 and June 2019 at our institution were retrospectively reviewed. Patients were eligible for this case-control study if they were diagnosed as single level fracture in spine. After inclusive and exclusive criteria were met, a total of 139 patients with IVC were enrolled as the study group. Non-IVC controls were matched in a 1:1 ratio in age (within 3 years), sex and fracture severity with patients in study group. Cement leakage were classified into four types [type B (through basivertebral vein), type S (through segmental vein), type-C (through a cortical defect), and type D (intradiscal leakage)], furtherly into two types [venous type (type-B or/and type S) and cortical type (type-C or/and type-D)]. A general leakage rate and a specific leakage rate per each type were compared between both groups.

Results

Each group included 139 patients. Groups were homogenous for age, sex, fracture severity, fracture location, fracture type, cement volume, puncture approach and property of cement. Compared with control group, IVC group had a significantly lower rate of type-B (20.9% vs. 31.7%, P = 0.041), type-S (24.5% vs. 52.5%, P = 0.000), and venous type leakage (37.4% vs. 67.6%, P = 0.000), a significantly higher rate of type-C (25.9% vs. 12.2%, P = 0.004), type-D (16.5% vs. 6.5%, P = 0.009), and cortical type leakage (40.3% vs. 16.5%, P = 0.000), no significant difference on the rate of general leakage (67.6% vs. 76.3%, P = 0.109).

Conclusion

IVC decreased the risk of cement leakage through vein and increased the risk of cement leakage through cortex. However, it had no significant effect on the occurrence of general leakage.

Comparison of Intravertebral Clefts between Kümmell Disease and Acute Osteoporotic Vertebral Compression Fracture: A Radiological Study

Objective

The aim of this study was to compare the radiological features of intravertebral clefts (IVC) between Kümmell disease (KD) and acute osteoporotic vertebral compression fracture (OVCF).

Materials and Methods

This is a retrospective study. A total of 79 patients with IVC from January 2014 to December 2018 were included in this study. There were 22 men and 57 women, with an average of 73.5 years. Based on the exact time interval from injury to treatment and the pathological examination results, the patients were divided into KD group (44 patients) and acute OVCF group (35 patients). The two groups were compared by the margin sclerosis of IVC, vertebra and pedicle ossification, stress fracture of the spinous process, paravertebral callus, the shape of IVC, cleft in the adjacent disc, and flatness of IVC's margin from plain radiographs and computed tomography (CT). The two groups were compared by the IVC content, double‐line sign, and signal of fracture vertebral from their magnetic resonance imaging (MRI).

Results

There were no significant differences in sex, age, and fracture distribution between the KD group and the acute OVCF group. IVC was present in both the KD group and the acute OVCF group. Six radiological features were only present in the KD group, including sclerosis of the cleft margin (95.5%, 42/44), ossification of the fractured vertebrae (100%, 44/44), ossification of the pedicle (31.8%, 14/44), double‐line sign (27.3%, 12/44), stress fracture of the spinous process (13.6%, 6/44), and even formation of paravertebral callus (18.2%, 8/44). Although there were statistical differences in the other four radiological features of content of IVC (P = 0.02), cleft sign in adjacent intervertebral disc (P < 0.01), margin of IVC (P = 0.02), and the shape of IVC (P = 0.01) between the KD group and acute OVCF group, these characteristics could be found in both groups.

Conclusion

IVC could present in patients with both KD and acute OVCF; however, we found that marginal cleft sclerosis, vertebral and pedicle ossification, double‐line sign, spinous process fracture, and formation of paravertebral callus are unique radiological features of KD and could be used for differentiation of KD from acute OVCF with IVC.

Intravertebral cleft in pathological vertebral fracture resulting from spinal tuberculosis: a case report and literature review

Background

Among common findings in osteoporotic vertebral compression fractures (OVCFs), the intravertebral cleft (IVC) is usually considered a benign lesion. The current study was aimed to present a rare case of vertebral fracture caused by IVC-related spinal tuberculosis.

Case presentation

A 73-year-old female complained of back pain and weakness in lower limbs for 2 weeks. 3 months ago, after a minor trauma, she got back pain without weakness in lower limbs. Initially, she was diagnosed with a L1 compression fracture and accepted conservative treatment. After an asymptomatic period, she complained progressive pain at the fracture position with weakness of both lower limbs and was referred to our hospital with suspicion of Kümmell’s disease. The patient underwent posterior debridement and internal fixation for decompression and stabilization of the spine. Pathological examinations revealed the patient with spinal tuberculosis.

Conclusions

Although IVC is common in patients with OCVFs, there are some cases believed to be found in patients with spinal tuberculosis or infection. Further test, like CT-guided puncture biopsy, may be required before decisive treatment when an IVC is observed.

Analysis of two minimally invasive procedures for osteoporotic vertebral compression fractures with intravertebral cleft: a systematic review and meta-analysis

Background

A systematic review and meta-analysis to assess the pros and cons of percutaneous vertebroplasty (PVP) versus kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs) with intravertebral cleft (IVC) including all available evidence from controlled trials.

Methods

Databases including Pubmed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched to identify relevant studies comparing PVP and PKP for OVCFs with IVC. The outcomes mainly included visual analog scale (VAS), Oswestry Disability Index (ODI), local kyphotic angle (LKA), rate of vertebral height (VH%), and adverse events.

Results

Nine studies enrolling 688 patients were eligible for meta-analysis. The results indicated no significant differences between the two groups in the short-and long-term VAS, ODI, LKA, or VH% (P > 0.05). Compared with PVP, PKP was associated with significantly longer operation time (P < 0.05), higher cost (P > 0.05), and more injected cement volume (P < 0.05). In terms of adverse events, PKP has a lower risk of cement leakage (P < 0.05), while with no significant difference in adjacent-level fracture rates (P > 0.05).

Conclusion

The two procedures have similar short- and long-term pain relief, functional recovery, local kyphosis correction, and vertebral height maintenance in OVCFs with IVC. PKP is superior to PVP for the injected cement volume, and lower cement leakage rate, however, with longer operation time, more fluoroscopy times, and higher cost. Further randomized controlled trials (RCTs) should be conducted to confirm these results.

Efficacy and Safety of High-Viscosity Bone Cement Vertebroplasty in Treatment of Osteoporotic Vertebral Compression Fractures with Intravertebral Cleft

OBJECTIVE

To evaluate and compare clinical outcomes and cement leakage of high-viscosity bone cement versus low-viscosity bone cement vertebroplasty in treating osteoporotic vertebral compression fractures with intravertebral cleft.

METHODS

The study included 72 patients with osteoporotic vertebral compression fractures with intravertebral cleft, who were divided into high-viscosity cement (HVC) (38 cases) and low-viscosity cement (LVC) (34 cases) groups according to the viscosity of bone cement used. Cement leakage, visual analog scale score, Oswestry Disability Index, and kyphotic angle (KA) were evaluated.

RESULTS

All patients were followed for at least 12 months. Overall cement leakage rate was 18.4% in the HVC group, lower than the rate of 61.8% obtained in the LVC group. A statistically significant difference was found in the overall cement leakage rate between the groups (P < 0.05). Visual analog scale and Oswestry Disability Index scores were significantly improved after percutaneous vertebroplasty without significant differences between the HVC and LVC groups (P > 0.05). The KA of patients from both groups was also significantly corrected immediately after surgery. Although the KA gradually increased in both groups during the follow-up period, there was no statistically significant difference between the HVC and LVC groups in KA during follow-up (P > 0.05).

CONCLUSIONS

Percutaneous vertebroplasty using HVC to treat osteoporotic vertebral compression fractures with intravertebral cleft significantly reduces cement leakage and improves the safety of the operation. In terms of clinical efficacy and prevention of augmented vertebral recollapse, HVC may not have obvious advantages.

Mechanism of formation of intravertebral clefts in osteoporotic vertebral compression fractures: An in vitro biomechanical study

BACKGROUND CONTEXT

Intravertebral clefts (IVCs) are vacuum-like cavities commonly associated with osteoporotic vertebral compression fractures (OVCFs). IVCs promote cement leakage during kyphoplasty, suggesting a physical link with the basivertebral foramen, although this is uncertain.

PURPOSE

The present study aims to create IVCs in mechanical experiments on cadaveric spines in order to clarify their pathogenesis, structure, and links with the basivertebral foramen.

STUDY DESIGN AND METHODS

In total, 15 three-vertebra lumbar specimens from five cadavers aged 68 to 71 years were subjected to axial compressive overload followed by cyclic loading in flexion and extension to create an OVCF together with an IVC. Computed tomography scans and radiographs were used to confirm structural changes and micro-CT was used to measure trabecular bone properties in five specimens. Unipedicular vertebroplasty was then performed on 10 damaged specimens until fluoroscopy revealed extravasation of cement.

RESULTS

In every specimen, loading created an OVCF with an IVC. Dissection and imaging showed that the IVC was always connected with the basivertebral foramen. The central vertebral region, including the IVC, had the lowest connectivity density, trabecular number, and bone volume fraction, and the highest trabecular separation. Vertebroplasty caused cement leakage through the basivertebral foramen in nine specimens and into an adjacent disc in one specimen.

CONCLUSION

Cyclic loading in flexion and extension applied to a fractured osteoporotic vertebra can create an IVC, which then allows cement leakage via the basivertebral foramen.

Risk Factors for Cement Loosening after Vertebroplasty for Osteoporotic Vertebral Fracture with Intravertebral Cleft: A Retrospective Analysis

STUDY DESIGN

Retrospective case-control study.

PURPOSE

To evaluate the primary outcomes and radiographic results of percutaneous vertebroplasty (PVP) in patients with singlelevel osteoporotic vertebral fracture (OVF) with intravertebral cleft (IVC) to identify the risk factors for cement loosening after PVP.

OVERVIEW OF LITERATURE

PVP is a widely accepted method for managing painful OVF; however, cement loosening occasionally occurs with poor outcomes.

METHODS

This retrospective study involved 195 patients treated with PVP for single-level OVF with IVC. Six months thereafter, the primary outcomes were evaluated using the Visual Analog Scale (VAS) for back pain and the modified Oswestry Disability Index. Computed tomography was conducted to detect cement loosening. Possible risk factors, such as age, sex, wedging angle, intravertebral instability, Parkinson's disease, spinous process fracture, ankylosing spinal hyperostosis, split vertebrae, and adjacent intervertebral vacuum, were assessed.

RESULTS

Forty-nine patients (25%) experienced cement loosening 6 months after PVP. The mean VAS scores were significantly higher in patients with cement loosening than in those without (50 vs. 26 mm, respectively; p <0.01). Cement loosening was closely associated with intravertebral instability (odds ratio [OR], 1.20; 95% confidence interval [CI], 1.04-1.40; p =0.015), Parkinson's disease (OR, 54.31; 95% CI, 4.47-659.53; p =0.002), spinous process fracture (OR, 7.11; 95% CI, 1.65-30.60; p =0.009), and split vertebrae (OR, 11.59; 95% CI, 1.64-82.02; p =0.014).

CONCLUSIONS

Patients with cement loosening experienced worse back pain than those without cement loosening. The important risk factors that influenced cement loosening after PVP were high intravertebral instability, Parkinson's disease, spinous process fracture, and split vertebrae.

Posttraumatic Delayed Vertebral Collapse : Kummell's Disease

Posttraumatic delayed vertebral collapse, known as Kummell’s disease, is increasing in number of patients. This disease is already progressive kyphosis due to vertebral collapse at the time of diagnosis and it causes intractable pain or neurologic deficit due to intravertebral instability. Treatment is very difficult after progression of the disease, and the range of treatment, in hospital day, and cost of treatment are both increased. Clinical features, pathogenesis and radiologic findings of these disease groups were reviewed to determine risk factors for delayed vertebral collapse. The purpose of this article is to suggest appropriate treatment before vertebral collapse for patients with osteoporotic vertebral compression fracture who have risk factors for posttraumatic delayed vertebral collapse.

Risk Factors for Recollapse of the Augmented Vertebrae After Percutaneous Vertebral Augmentation: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Recollapse of the augmented vertebrae after percutaneous vertebral augmentation treatment for osteoporotic vertebral compression fractures has obtained much attention. Although many potential risk factors have been proposed, they are still disputed. The aim of our study was to identify the characteristics of the augmented vertebrae that had undergone a recollapse according to a systematic review from the earliest available records up to August 2017 and then conduct a meta-analysis based on eligible studies to assess significant potential risk factors for recollapse of the augmented vertebrae.

METHODS

Fourteen studies were identified for investigating recollapse of the augmented vertebrae. Of those studies, 9 studies were eligible for meta-analysis.

RESULTS

Pooled results showed that 5 primary factors were associated with recollapse of the augmented vertebrae, including preoperative intravertebral cleft, the affected vertebrae in the thoracolumbar region, preoperative severe kyphotic deformity, solid lump cement distribution pattern, and higher vertebral height restoration. It was possibly another risk factor that the distance between PMMA and superior end plate was relatively large.

CONCLUSIONS

Careful observation of patients with these risk factors and reasonable intervention could be useful to prevent deterioration of their clinical course.

Intravertebral cleft in pathological vertebral collapse resulting from cancer metastasis: report of three cases

Intravertebral cleft (IVC) is a common finding in osteoporotic compression fracture. However, since the vertebral collapse attributable to cancer metastasis is rarely associated with IVC, the phenomenon is generally considered as a sign of a benign lesion. In this study, we retrospectively reviewed the radiographs, computed tomography scans, and magnetic resonance images of 111 patients with spinal metastasis. Three cases (2.7 %) had IVC in the collapsed thoracic vertebral bodies (T7, T8, and T11) attributable to cancer metastasis. IVC alone is not necessarily an indicator of a benign vertebral collapse.

Efficacy of Percutaneous Vertebroplasty in the Treatment of Osteoporotic Vertebral Compression Fractures with Intravertebral Cleft

Intravertebral cleft (IVC) is frequently observed in patients with painful osteoporotic vertebral compression fracture (OVCF). Some studies reported the usefulness of percutaneous vertebroplasty (PVP) for treating OVCF with IVC. However, systematic studies are scarce, and their results are conflicting. The purpose of this study was to evaluate the clinical and radiographic results of PVP in the treatment of painful OVCF with IVC. Two hundred ninety-one patients with OVCF with IVC underwent PVP. Back pain was measured using a visual analog scale (VAS), and physical disability was assessed using the Oswestry Disability Index (ODI). Three radiological parameters were assessed: the local kyphotic angle, percentage spinal canal cross-sectional area of compromise, and intravertebral instability of the affected vertebra. The mean follow-up period was 28 months. The mean values for the VAS and ODI were 8.4 and 60.0%, respectively, before PVP, versus 3.9 and 35.4%, respectively, at the final follow-up. The average local kyphotic angle, percentage spinal canal cross-sectional area of compromise, and intravertebral instability were 10.5°, 17.9% and 6.1°, respectively, before PVP and 8.1°, 15.2%, and 0.8°, respectively, at the final follow-up. There were no neurological or systemic complications due to cement leakage. PVP is an effective and safe intervention for treating OVCF with IVC.

Comparison of percutaneous vertebroplasty and percutaneous kyphoplasty for the management of Kümmell's disease: A retrospective study

BACKGROUND

Post traumatic osteonecrosis of a vertebral body occurring in a delayed fashion was first described by the German doctor Kümmell in 1895. Several studies have reported percutaneous vertebroplasty (PVP), or percutaneous kyphoplasty (PKP) for Kümmell's disease achieves good outcomes. However, it is unknown whether a technique is superior for the treatment of this disease. The objective of the study is to compare the efficacy of PVP and PKP for the treatment of Kümmell's disease.

MATERIALS AND METHODS

A retrospective review was conducted for 73 patients with Kümmell's disease. PVP was performed in 38 patients and PKP in 35 patients. Visual analogue score (VAS) was used to evaluate pain. The anterior vertebral height was measured. The operative time, the incidence of cement leakage and the costs were recorded.

RESULTS

In both PVP group and PKP group, the VAS and anterior vertebral height significantly improved at 1-day postoperatively (P < 0.05), and the improvement sustained at the final followup (P > 0.05). Between the PVP and PKP groups, there were no significant differences in VAS and the anterior vertebral height at 1-day postoperatively and at the final followup (P > 0.05). The operating time and expense in the PKP group were higher than the PVP group (P < 0.001). Cement leakages in the PKP group were fewer than PVP group (P < 0.05).

CONCLUSIONS

PVP is a faster, less expensive option that still provides a comparable pain relief and restoration of vertebral height to PKP for the treatment of Kümmell's disease. PKP has a significant advantage over PVP in term of the fewer cement leakages.

Basivertebral foramen could be connected with intravertebral cleft: a potential risk factor of cement leakage in percutaneous kyphoplasty

BACKGROUND CONTEXT

Among different types of cement leakage in percutaneous kyphoplasty (PKP) for osteoporotic vertebral body compression fractures, leaks into the spinal canal are considered to be the most common complication. One potential structure causing this type of cement leakage is the potential connection between the basivertebral foramen and the intravertebral cleft, which is revealed clearly on magnetic resonance (MR) images, but is often ignored in the literature.

PURPOSE

The purpose of this study is to assess the incidence rate of different types of cement leakage in PKP with or without intravertebral clefts and to determine whether the basivertebral foramen could be connected to the intravertebral cleft.

STUDY DESIGN

This study is a retrospective assessment of the presence of an intravertebral cleft in osteoporotic vertebral bodies and the different types of cement leakage after PKP on radiographs, computed tomographic (CT) scans, and MR images.

PATIENT SAMPLE

A total of 164 consecutive patients underwent PKP to treat 204 osteoporotic vertebral compression fractures.

OUTCOME MEASURES

Outcome measures include the occurrence of different types of cement leakage in the groups with an intravertebral cleft and without intravertebral clefts.

METHODS

A total of 204 vertebrae in 164 consecutive patients who underwent PKP to treat osteoporotic vertebral compression fractures were classified into two patterns based on preoperative radiographs, CT scans, and/or MR images of the treated levels: cleft pattern (with an intravertebral cleft in the vertebral body) and trabecular pattern (without intravertebral clefts). When an intravertebral cleft was identified, the investigators examined the basivertebral foramen and looked for a communication between the two structures on three-dimensional CT scans and MR images. On direct postoperative images, the patterns of cement leakage were classified as five types: type A, through a cortical defect into the paraspinal soft tissues; type B, through the basivertebral foramen; type C, via the needle channel; type D, through a cortical defect into the disc space; and type E, via the paravertebral vein. The association of the distribution of the cement leakage and the presence of an intravertebral cleft was analyzed retrospectively. Moreover, the association of type B leakage with the communication between the basivertebral foramen and the intravertebral cleft was also assessed.

RESULTS

The average interobserver kappa values for determining the type of cement leakage and the presence of intravertebral cleft were 0.916 (range, 0.792-1) and 0.935, respectively. In 41 of 204 vertebrae (19.9%), an intravertebral cleft was confirmed on preoperative images. A communication between the intravertebral cleft and the basivertebral foramen was seen in 10 vertebrae (24.4%). Cement leakage was 36.2% in the group with a trabecular pattern and 41.5% in the group with a cleft pattern (p>.05). Leaks through the basivertebral foramen (type B; N=30, 14.7%) and through cortical defects into the disc space (type D; N=14, 6.9%) were more common than other types. Twenty of 163 vertebrae with the trabecular pattern (12.3%) and 10 of 41 vertebrae with the cleft pattern (24.4%) were identified as type B leaks, which reached statistical significance (p<.05). There was no statistical difference between the trabecular pattern and the cleft pattern on other types of leaks.

CONCLUSIONS

Type B leaks are more common in vertebrae with an intravertebral cleft, which supports the presence of a connection between an intravertebral cleft and the basivertebral foramen. Thus, care must be taken when PKP is performed in these patients to avoid direct cement leakage into the spinal canal through the basivertebral foramen.

Pathomechanism of intravertebral clefts in osteoporotic compression fractures of the spine

BACKGROUND CONTEXT

Intravertebral cleft (IVC) associated with vertebral collapse is not uncommon in osteoporotic compression fracture. However, the pathomechanism of IVC is poorly understood. Bone ischemia is indicated in the current hypothesis.

PURPOSE

To clarify the pathomechanism of IVC in delayed posttraumatic vertebral collapse, referred to as Kummell's disease.

STUDY DESIGN

Magnetic resonance (MR) angiography and histology of segmental arteries and vertebral bodies in delayed posttraumatic vertebral collapse were investigated.

PATIENT SAMPLE

All elderly patients admitted to the authors' spine clinic of tertiary referral center for a 105-month period.

OUTCOME MEASURES

All imaging tests including plain radiographs, computed tomography, and MR angiography were reviewed by authors using a double-blind method. All operations were performed by one experienced surgeon. The statistical data were analyzed using SPSS program.

METHODS

Evaluations using MR angiography and computed tomography were performed in 22 patients. Twelve of the 22 patients underwent corpectomy and anterior interbody fusion. At operation, segmental artery and bone surrounding IVC were harvested and microscopically evaluated.

RESULTS

Magnetic resonance angiography showed occlusions of bilateral segmental arteries in nine of 22 patients. Seven patients had unilateral occlusion. In six patients, no occlusion was seen. Microscopically, the left segmental arteries of three patients were completely obstructed by thrombosis. Histologic examination of necrotic bone showed fragile trabecular bone and sparse osteocytes.

CONCLUSIONS

The findings of thrombosis of the segmental arteries of the vertebral body with IVC could suggest a mechanism by which IVC is formed, and the progressive collapse may develop following osteoporotic spinal fracture.

Percutaneous balloon kyphoplasty of osteoporotic vertebral compression fractures with intravertebral cleft

BACKGROUND

Intravertebral cleft is a structural change in osteoporotic vertebral compression fractures (OVCF), which is the manifestation of ischemic vertebral osteonecrosis complicated with fracture nonunion and pseudoarthrosis and appears in the late stage of OVCF. Despite numerous studies on OVCF, few aim to evaluate the clinicoradiological characteristics and clinical significance of intravertebral cleft in OVCF. This study investigates clinicoradiological characteristics of intravertebral cleft in OVCF and the effect on the efficacy of percutaneous balloon kyphoplasty (PKP).

MATERIALS AND METHODS

PKP was performed on 139 OVCF patients without intravertebral cleft (group A) and 44 OVCF patients with intravertebral cleft (group B). The frequency distribution of the affected vertebral body, bone cement infusion volume, imaging manifestation, leakage rate and type, preoperative and postoperative height of the affected vertebral body, visual analog scale (VAS) and Oswestry disability index (ODI) score were evaluated.

RESULTS

Significant differences were found in the frequency distribution of the affected vertebral body and bone cement leakage type between the two groups (P < 0.05). However, differences in bone cement infusion volume and leakage rate (P > 0.05) were not detected. In both groups, the postoperative height of the affected vertebral body was significantly improved (P < 0.05). The restoration of vertebral body height in group B was more evident than that in group A (P < 0.05). The preoperative VAS and ODI scores in group B were significantly higher than those in group A (P < 0.05). After surgical treatment, pain relief and daily activity function in both groups were significantly improved (P < 0.05), and no significant difference in postoperative scores was detected between the two groups (P > 0.05).

CONCLUSION

Intravertebral cleft exhibits specific clinical and imaging as well as bone cement formation characteristics. PKP can effectively restore the affected vertebral body height, alleviate pain, and improve daily activity function of patients.

Vertebra plana: reappraisal of a contraindication to percutaneous vertebroplasty

PURPOSE

We evaluated the efficacy of percutaneous vertebroplasty (PVP) in treating symptomatic vertebra plana, which is considered a relative contraindication to the procedure.

METHODS

Out of 540 levels treated in 260 patients, we treated 40 patients (mean age: 74 years) with vertebra plana between T6 and L3 (37 osteoporotic and 3 metastatic levels). In most cases, the vertebra was accessed with fluoroscopic guidance from a single, transpedicular approach. All patients underwent a preliminary MRI examination, an immediate, post-procedure radiological examination, and a follow-up examination (mean duration, 6 months).

RESULTS

Both immediate and follow-up examinations showed that the mean pain and physical disability scores were significantly reduced compared to the scores before treatment (p ≤ 0.001). No complications occurred during the procedures. In 23/40 cases, asymptomatic intradiscal cement leakage occurred. Posterior or perivertebral leakage never occurred. In most cases, an intravertebral cleft was present, and we filled it with polymethylmethacrylate, which healed the pseudarthrosis. Partial vertebral height was restored in 7 cases. In 6 cases, a new fracture occurred between 1 and 3 months at a different level from the treated level.

CONCLUSION

Our preliminary results showed that PVP was a safe, effective treatment for symptomatic vertebra plana; thus, it should not be discounted for this group of patients. In most cases, the procedure was favored by the presence of an intravertebral cleft that appeared to contribute to minimizing the risk of posterior cement leakage. Filling the cleft with polymethylmethacrylate allowed intravertebral stabilization.

Resolution of epidural hematoma related to osteoporotic fracture after percutaneous vertebroplasty

We are the first to report a case that showed spontaneous resolution of epidural hematoma which was related to a steroid-induced osteoporotic compression fracture. The patient had a painful fracture with an intravertebral cleft at L1 accompanying an epidural hematoma posteriorly. Immediate pain relief was achieved after percutaneous vertebroplasty. Complete resolution of hematoma was noted three months after procedure. We theorized that intravertebral stability after treatment might have played a role in this patient.

Usefulness of prone cross-table lateral radiographs in vertebral compression fractures

Background

Dynamic radiographs are recommended to investigate non-healing evidence such as the dynamic mobility or intravertebral clefts in osteoporotic vertebral compression fractures (VCFs). However, it is difficult to examine standing flexion and extension lateral radiographs due to severe pain. The use of prone cross-table lateral radiographs (PrLRs) as a diagnostic tool has never been proposed to our knowledge. The purpose of this study is to clarify the usefulness of PrLRs in diagnosis and treatment of VCFs.

Methods

We reviewed 62 VCF patients examined with PrLRs between January 1, 2008 and June 30, 2011. To compare the degree of pain provoked between standing extension lateral radiographs (StLRs) and PrLRs, numeric rating scale (NRS) scores were assessed and compared by a paired t-test. Vertebroplasty was done for 40 patients and kyphoplasty was done for 9 patients with routine manners. To assess the degree of postural reduction, vertebral wedge angles (VWA) and vertebral height ratios (VHR) were calculated by using preoperative StLRs, PrLRs, and postoperative lateral radiographs. Two variables derived from changes in VWA and VHR between preoperative and postoperative radiographs were compared by a paired t-test.

Results

The average NRS scores were 6.23 ± 1.67 in StLRs and 5.18 ± 1.47 in PrLRs. The degree of pain provocation was lower in using PrLRs than StLRs (p < 0.001). The average changes of VWA between preoperative and postoperative status were 5.24° ± 6.16° with PrLRs and 3.46° ± 3.47° with StLRs. The average changes of VHR were 0.248 ± 0.178 with PrLRs and 0.148 ± 0.161 with StLRs. The comparisons by two variables showed significant differences for both parameters (p = 0.021 and p < 0.001, respectively). The postoperative radiological status was reflected more precisely when using PrLRs than StLRs.

Conclusions

In comparison with StLR, the PrLR was more accurate in predicting the degree of restoration of postoperative vertebral heights and wedge angles, and provoked less pain during examination. The PrLR could be a useful diagnostic tool to detect intravertebral cleft or intravertebral dynamic instability.