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

Anatomical and biomechanical characteristics of basivertebral foramen and its clinical significance

Basivertebral foramen is a natural orifice in the posterior wall of the vertebral body existing in humans and mammals, through which the basal vertebral vein, branch of lumbar artery and recurrent branch of spinal nerve enter and exit the vertebral body. Basivertebral foramen changes the local microstructure of the vertebral body, resulting in cortical defect and sparse trabecular bone in the central region of the vertebral body, thus affecting its biomechanical characteristics and making its central region a "weak" area of the vertebra. Some characteristic injuries of the vertebra are related to basivertebral foramen, such as vertebral compression fracture and intervertebral cleft, vertebral burst fracture and posterior upper vertebral fracture fragment, and cement leakage during treatment. In this article, the anatomical and developmental biological characteristics of basivertebral foramen, the impact of basivertebral foramen on biomechanical characteristics, and the treatment of basivertebral foramen related vertebral diseases are reviewed, in order to provide references for the clinical diagnosis and treatment of vertebral injuries.

Evaluation of the clinical efficacy of the bilateral pedicle cement anchoring technique in percutaneous vertebroplasty for Kümmell disease

The present study aimed to evaluate the clinical efficacy of the bilateral pedicle cement anchoring technique combined with the postural reduction in percutaneous vertebroplasty (PVP) for Kümmell disease. For this purpose, a retrospective study was performed on 18 patients with Kümmell disease who between January 2018 and June 2021 underwent bilateral pedicle cement anchoring combined with postural reduction in PVP. Pre- and post-operative bone mineral density, injected cement volume, visual analogue scale (VAS) values, Oswestry disability index (ODI) scores, Cobb angle measurements and anterior vertebral height (AVH) were recorded and assessed. The mean follow-up duration was 8.4±1.2 months. The average VAS score decreased from 8.17±0.71 pre-operatively to 1.56±0.62 post-operatively and remained at 2.00±0.91 at the final follow-up visit (P<0.05). The average ODI improved from 86.44±5.5 pre-operatively to 24.33±7.82 post-operatively. Until the last follow-up, the ODI remained at 27.11±8.76 (P<0.05). Similarly, the changes in the Cobb angle and AVH before and after surgery were also statistically significant in the radiological evaluation (P<0.05). During the follow-up, two patients experienced adjacent vertebral fractures. The loosening of cement was not found. Overall, the present study demonstrated that during the treatment of Kümmell disease with PVP, the bilateral pedicle cement anchoring technique combined with postural reduction can achieve good clinical outcomes.

Comparison of Percutaneous Kyphoplasty With or Without Posterior Pedicle Screw Fixation on Spinal Sagittal Balance in Elderly Patients With Severe Osteoporotic Vertebral Compression Fracture: A Retrospective Study

Objective

To compare the effects of percutaneous kyphoplasty (PKP) with or without posterior pedicle screw fixation (PPSF) on spinal sagittal balance in elderly patients with severe osteoporotic vertebral compression fracture (sOVCF).

Methods

From January 2016 to December 2018, 102 elderly patients with single-level thoracolumbar sOVCF were enrolled. Among them, 78 cases underwent PKP (Group A), and 24 cases underwent PPSF+KP (Group B). Clinical evaluation included perioperative parameters, Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for back pain; Radiographic evaluation included anterior vertebral height (AVH) and rate (AVHr), local kyphotic angle (LKA), and spino-pelvic sagittal balance parameters.

Results

Perioperative parameters including operation time, blood loss, fluoroscopic time and hospital stay in Group A were less than those in Group B (p &lt; 0.05). Compared with the pre-operative results, the ODI and VAS scores of both groups decreased significantly in the three follow-ups after surgery (p &lt; 0.05). The post-operative ODI and VAS scores of Group A were significantly better than those of Group B, but the results were opposite at the final follow-up (p &lt; 0.05). Compared with the pre-operative values, except that there was no significant difference in pelvic incidence (PI) (p &gt; 0.05), other radiographic parameters of both groups were improved significantly in the three follow-ups after surgery (p &lt; 0.05). The AVH, AVHr, LKA and lumbar lordosis (LL) in Group B were better than those in Group A in the three follow-ups after surgery (p &lt; 0.05). At the final follow-up, the sacral slope (SS) and pelvic tilt (PT) differed significantly between the two groups (p &lt; 0.05).

Conclusions

Both PPSF+KP and PKP can achieve favorable clinical outcomes and maintain the spinal sagittal balance. Compared with PPSF+KP, PKP showed more significant advantages in the early post-operative period. However, in the long-term follow-up, PPSF+KP showed better clinical outcomes and may be better than PKP in maintaining spinal sagittal balance.

Treatment of Kümmell’s disease following the occurrence of osteoporotic vertebral compression fracture

Background: The incidence of osteoporotic vertebral compression fracture (OVCF) is increasing with the increase in the elderly population. Kümmell’s disease following OVCF occurrence is not a rare complication and is frequently associated with severe pain or neurologic deficit with progressive kyphotic deformity. Kümmell’s disease initially meant post-traumatic delayed vertebral collapse, but now it is also termed nonunion, osteonecrosis, or intravertebral vacuum cleft, all of which suggest the disruption of the healing process.Current Concepts: The major pathogenesis of Kümmell’s disease is a vascular compromise caused by mechanical stress or intravascular pathology. The key radiologic sign to diagnose Kümmell’s disease is the presence of intravertebral vacuum cleft, observed using simple X-ray, computed tomography, or magnetic resonance imaging. Magnetic resonance imaging is the most useful diagnostic tool showing gas or fluid signals. The risk factors for the progression of Kümmell’s disease after OVCF include middle-column injury, confined low signal intensity on T2-weighted image, posterior wall combined fracture, kyphotic angle >10°, and a height loss >15%. Its treatment can be broadly classified as conservative treatment, bone cement injection, and surgical treatment. The appropriate treatment method is selected based on the pain intensity, neurological symptoms, and the severity of the kyphotic deformity.Discussion and Conclusion: Kümmell’s disease usually develops along with osteoporosis. Therefore, the treatment should be focused on relief from symptoms associated with Kümmell’s disease and osteoporosis. It is recommended that an anabolic agent should be administered after the diagnosis of Kümmell’s disease, regardless of the treatment modality.

Comparison of Percutaneous Kyphoplasty with or without Pedicle Screw Fixation in Osteoporotic Thoracolumbar Vertebral Fractures: A Retrospective Study

Background

Osteoporotic thoracolumbar compression fractures have become a great social burden due to the aging tendency of population. This study is aimed at comparing the clinical and radiological outcomes of percutaneous kyphoplasty with or without pedicle screw fixation in patients with osteoporotic thoracolumbar fractures. Hypothesis. There is a difference in clinical outcomes between percutaneous kyphoplasty with pedicle screw fixation and percutaneous kyphoplasty.

Methods

This retrospective study included 87 patients who received percutaneous kyphoplasty with or without pedicle screw fixation between October 2015 and October 2017 at Ningbo No.6 Hospital and were followed for 2 years. A total of 40 patients received percutaneous kyphoplasty with pedicle screw fixation (PKPF group), and the other 47 patients had percutaneous kyphoplasty only (PKP group). The outcomes were measured using the visual analogue scale (VAS), Oswestry Disability Index (ODI), Cobb angle (CA), and anterior vertebra height rate (AVHr), which were calculated at preoperative admission and each follow-up visit. Complications including postoperative back pain, refracture, and fixation failure were collected from medical records.

Results

There was no significant difference in baseline characteristics or preoperative data between the two groups (p < 0.05) but significantly better improvements in VAS, ODI, CA, and AVHr at 12- and 24-month follow-up visits in the PKPF group compared with those of the PKP group. 23 (48.9%) patients in the PKP group had complications, whereas only 5 (12.5%) patients in the PKPF group presented complications including 2 postoperative back pain and 1 fixation failure (p = 0.04).

Conclusions

PKPF obtained longer correction and better improvement in VAS, ODI, and CA in patients with osteoporotic thoracolumbar vertebral fractures than PKP.

Outcomes of Augmentation in Osteoporotic Vertebral Compression Fractures Showing a Cleft Sign on MRI

INTRODUCTION

Intravertebral clefts (IVCs) typically occur in association with osteoporotic vertebral compression fractures (OVCFs) and can be characterized based on magnetic resonance imaging (MRI). This study aimed to identify the clinical characteristics of IVCs with different MRI signals and assess their influence on outcomes of vertebral augmentation.

MATERIALS AND METHODS

We retrospectively recruited patients with OVCFs and associated IVCs who underwent vertebral augmentation. Patients were stratified into two groups based on whether the IVCs were full of liquid or gas, as determined by MRI signals. Patients were also stratified based on whether vertebral augmentation involved percutaneous kyphoplasty (PKP) or vertebroplasty (PVP). Pre- and postprocedural parameters were compared between groups.

RESULTS

A total of 194 fractured vertebrae (86 liquid-filled, 108 gas-filled) were examined. Scores for bone cement distribution were significantly higher in the gas group than in the liquid group, indicating broader cement distribution in the gas group. In both groups, intervention significantly improved pain and mobility scores. Among patients with gas-filled IVCs, the incidence of bone cement leakage and recollapse of treated vertebrae were significantly higher after PKP than after PVP. In the liquid group, incidence of bone cement leakage and recollapse of treated vertebrae did not differ significantly between patients who received PKP or PVP.

CONCLUSION

Vertebral augmentation is effective for treating OVCFs with gas- or liquid-filled IVCs. However, in patients with gas-filled IVCs, PKP may be associated with higher incidence of cement leakage and recollapse of treated vertebrae than PVP. Liquid-filled IVCs may not promote bone cement distribution.

Basivertebral foramina of true vertebrae: morphometry, topography and clinical considerations

PURPOSE

Basivertebral foramina (BVF) are openings of the posterior wall of vertebral body (VB) that lead to basivertebral canals (BVC), where homonymous neurovascular bundle courses. BVF and BVC are implicated with spinal fractures, vertebral augmentation and basivertebral nerve radiofrequency ablation. Despite their essential clinical impact, knowledge of BVF precise anatomy is scarce. The current study describes in detail the BVF typical morphological and topographical anatomy, morphometry and variants.

METHODS

In total, 1561 dried true vertebrae of 70 Greek spines of known gender and age were examined. BVF number, location, shape and size (in foramina > 1 mm), BVF distance from VB rims and pedicles, as well as VB morphometry (diameters, heights and distance between pedicles) were studied. Ten spines were re-examined by computed tomography and BVC depth and shape were recorded. Correlations and differences were statistically analyzed.

RESULTS

C₁ lack BVF (3.4%). One BVF was found in 45.1%, two in 36.9%, three in 3.8% and four BVF in 0.6%. Multiple small (< 1 mm) foramina were observed in 10.1%. Asymmetry was detected in 12.3%. C₂ and T₁₀-L₁ presented typical pattern, whereas C₃ and T₂ had the greatest variability. BVF were significantly closer to the upper rim in C₂ and T₁₀-L₄ and to the lower rim in C₇-T₄, T₆-T₈ and L₅. The mean BVC depth was 12-21.8% of the VB anteroposterior diameter.

CONCLUSION

BVF number, shape, size and topography are described, in detail, per vertebral level. The provided morphological classification and the created cumulative BVF topographic graphs should assist in clinical practice and surgery.

Risk factors of cemented vertebral refracture after percutaneous vertebral augmentation: a systematic review and meta-analysis

To evaluate the risk factors of cemented vertebral refracture after percutaneous vertebral augmentation (PVA) for patients with osteoporotic vertebral compression fractures (OVCFs). We performed a literature search on cemented vertebral refracture after PVA using the PubMed, EMBASE, and Cochrane Library medical databases. The clinical data, including literature information, basic patient information, observational factors, and interventional factors, were extracted by two authors. The pooled results and related heterogeneity of each factor between the refracture group and the non-refracture group were evaluated using Review Manager software 5.35. A total of 3185 patients from 10 studies were included, with 195 patients in the refracture group and 2990 patients in the non-refracture group. The mean follow-up duration was 18.9 months. According to the meta-analysis, age, low bone marrow density (BMD), intravertebral cleft (IVC), high anterior vertebral height (AVH) restoration/high Cobb angle restoration, and low cement dose were the risk factors of cemented vertebral refracture after PVA. Our results showed that age, low BMD, IVC, high AVH restoration, high Cobb angle restoration, and low cement dose were the risk factors for cemented vertebral refracture after PVA.

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.