The cranial vertebral body suffers a higher risk of adjacent vertebral fracture due to the poor biomechanical environment in patients with percutaneous vertebralplasty.

BACKGROUND CONTEXT: Adjacent vertebral fracture (AVF), a frequent complication of PVP, is influenced by factors such as osteoporosis progression, increased intervertebral cement leakage (ICL), and biomechanical deterioration. Notably, the risk of AVF is notably elevated in the cranial vertebral body compared with the caudal counterpart. Despite this knowledge, the underlying pathological mechanism remains elusive. PURPOSE: This study delves into the role of biomechanical deterioration as a pivotal factor in the heightened risk of AVF in the cranial vertebral body following PVP. By isolating this variable, we aim to unravel its prominence relative to other potential risk factors. STUDY DESIGN: A retrospective study and corresponding numerical mechanical simulations. PATIENT SAMPLE: Clinical data from 101 patients treated by PVP were reviewed in this study. OUTCOME MEASURES: Clinical assessments involved measuring Hounsfield unit (HU) values of adjacent vertebral bodies as a representation of patients' bone mineral density (BMD). Additionally, the rates of ICL were compared among these patients. Numerical simulations were conducted to compute stress values in the cranial and caudal vertebral bodies under various body positions. METHODS: In a retrospective analysis of PVP patients spanning July 2016 to August 2019, we scrutinized the HU values of adjacent vertebral bodies to discern disparities in BMD between cranial and caudal regions. Additionally, we compared ICL rates on both cranial and caudal sides. To augment our investigation, well-validated numerical models simulated the PVP procedure, enabling the computation of maximum stress values in cranial and caudal vertebral bodies across varying body positions. RESULTS: The incidence rate of cranial AVF was significantly higher than the caudal side. No notable distinctions in HU values or ICL rates were observed between the cranial and caudal sides. The incidence of AVF showed no significant elevation in patients with ICL in either region. However, numerical simulations unveiled heightened stress values in the cranial vertebral body. CONCLUSIONS: In patients postPVP, the cranial vertebral body faces a heightened risk of AVF, primarily attributed to biomechanical deterioration rather than lower BMD or an elevated ICL rate.

[Effect of percutaneous kyphoplasty on lumbar-pelvic correlation in osteoporotic vertebral compressive fractures].

OBJECTIVE: To explore the effect of percutaneous kyphoplasty (PKP) on lumbar-pelvic correlation in osteoporotic vertebral compressive fracture (OVCF). METHODS: According to the inclusion criteria, 63 patients with primary osteoporosis between January 2012 and June 2017 were selected as the control group and 67 patients with single-segment lumbar OVCF receiving PKP and complete clinical data were included as the observation group. There was no significant difference in gender, age, and lumbar spine bone density between the two groups ( P>0.05). The visual analogue scale (VAS) score and Oswestry Disability Index (ODI) score were used to assess lumbar pain and function before operation and at 3 days after operation in the observation group; lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured in lumbar lateral X-ray films which were taken before PKP and at 1 month after PKP. The same parameters were measured in the lumbar lateral X-ray films which were taken at the time of initial diagnosis in the control group. RESULTS: All patients were followed up 3-24 months with an average of 5.8 months in the observation group. The VAS score decreased from 5.6±1.8 before PKP to 2.8±1.3 at 3 days after PKP ( t=14.082, P=0.000); ODI decreased from 50.1%±5.0% before PKP to 18.2%±1.8% ( t=47.011, P=0.000). Compared with the control group, the LL, PI, and SS decreased and the PT increased in the observation group, and only the difference in LL between the two groups was significant ( P<0.05). In the observation group, the LL and SS significantly increased ( P<0.05) and PT significantly decreased ( P<0.05) at 1 month after operation when compared with preoperative ones, and PI decreased, but the difference was not significant ( P>0.05). In the control group, LL was positively correlated with PI and SS ( P<0.05); PI was positively correlated with PT and SS ( P<0.05). In the observation group, PI was positively correlated with SS ( P<0.05) before and after PKP. CONCLUSION: OVCF patients lost the specific lumbar-pelvic correlation. PKP can restore lumbar lordosis, but it still can not restore the normal physiological fitting.

Effect of percutaneous kyphoplasty on lumbar-pelvic correlation in osteoporotic vertebral compressive fractures / 中国修复重建外科杂志

Objective: To explore the effect of percutaneous kyphoplasty (PKP) on lumbar-pelvic correlation in osteoporotic vertebral compressive fracture (OVCF). Methods: According to the inclusion criteria, 63 patients with primary osteoporosis between January 2012 and June 2017 were selected as the control group and 67 patients with single-segment lumbar OVCF receiving PKP and complete clinical data were included as the observation group. There was no significant difference in gender, age, and lumbar spine bone density between the two groups ( P>0.05). The visual analogue scale (VAS) score and Oswestry Disability Index (ODI) score were used to assess lumbar pain and function before operation and at 3 days after operation in the observation group; lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured in lumbar lateral X-ray films which were taken before PKP and at 1 month after PKP. The same parameters were measured in the lumbar lateral X-ray films which were taken at the time of initial diagnosis in the control group. Results: All patients were followed up 3-24 months with an average of 5.8 months in the observation group. The VAS score decreased from 5.6±1.8 before PKP to 2.8±1.3 at 3 days after PKP ( t=14.082, P=0.000); ODI decreased from 50.1%±5.0% before PKP to 18.2%±1.8% ( t=47.011, P=0.000). Compared with the control group, the LL, PI, and SS decreased and the PT increased in the observation group, and only the difference in LL between the two groups was significant ( P0.05). In the control group, LL was positively correlated with PI and SS ( P<0.05); PI was positively correlated with PT and SS ( P<0.05). In the observation group, PI was positively correlated with SS ( P<0.05) before and after PKP. Conclusion: OVCF patients lost the specific lumbar-pelvic correlation. PKP can restore lumbar lordosis, but it still can not restore the normal physiological fitting.

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.

Bone cement distribution patterns of osteoporotic vertebral fractures with intravertebral clefts after vertebroplasty / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.26.006

Effect of percutaneous kyphoplasty in treatment of acute and chronic osteoporotic vertebral compression fractures / 中国矫形外科杂志

[Objective]To analyze the therapeutic effects of percutaneous kyphoplasty for acute versus chronic osteoporotic vertebral compressive fracture.[Method]Percutaneous kyphoplasty was performed in 56 patients(137 vertebraes) with osteoporotic vertebral compression fracture (VCF).Based on the changes on MRI,all compression fractures were divided into 3 types:acute VCF,repairing VCF and chronic VCF.Types were examined for differences in treatment efficacy,according to the anterior/middle vertebral body height,Cobb's angle and visual analogue scale(VAS) at pre-and post-operation.[Result]All patients with the VCFs had rapid and significant improvement in back pain following percutaneous kyphoplasty.VAS was from 8.09?1.12 preoperatively to 2.31?0.91 postoperatively,and 2.26?0.88 at final follow-up.The results showed that 41 cases were Type Ⅰ on MRI,69 were Type Ⅱ and 27 were Type Ⅲ.Significant improvement was observed at the post-operative versus pre-operative assessments in Type Ⅰ and Type Ⅱ.No significant differences were observed between post-and pre-operative assessments in Type Ⅲ.[Conclusion]The curative effect of percutaneous kyphoplasty for the treatment of acute VCFs appears superior to that of chronic VCFs.After a definite diagnosis of VCFs,percutaneous kyphoplasty should be performed as early as possible in order to obtain a better therapeutic effect.