ObjectiveTo analyze the correlation between bone cement cortical leakage and injury degree of osteoporotic vertebral compression fracture (OVCF) after percutaneous kyphoplasty (PKP), and to provide guidance for reducing clinical complications. Methods A clinical data of 125 patients with OVCF who received PKP between November 2019 and December 2021 and met the selection criteria was selected and analyzed. There were 20 males and 105 females. The median age was 72 years (range, 55-96 years). There were 108 single-segment fractures, 16 two-segment fractures, and 1 three-segment fracture. The disease duration ranged from 1 to 20 days (mean, 7.2 days). The amount of bone cement injected during operation was 2.5-8.0 mL, with an average of 6.04 mL. Based on the preoperative CT images, the standard S/H ratio of the injured vertebra was measured (S: the standard maximum rectangular area of the cross-section of the injured vertebral body, H: the standard minimum height of the sagittal position of the injured vertebral body). Based on postoperative X-ray films and CT images, the occurrence of bone cement leakage after operation and the cortical rupture at the cortical leakage site before operation were recorded. The correlation between the standard S/H ratio of the injured vertebra and the number of cortical leakage was analyzed. Results Vascular leakage occurred in 67 patients at 123 sites of injured vertebrae, and cortical leakage in 97 patients at 299 sites. Preoperative CT image analysis showed that there were 287 sites (95.99%, 287/299) of cortical leakage had cortical rupture before operation. Thirteen patients were excluded because of vertebral compression of adjacent vertebrae. The standard S/H ratio of 112 injured vertebrae was 1.12-3.17 (mean, 1.67), of which 87 cases (268 sites) had cortical leakage. The Spearman correlation analysis showed a positive correlation between the number of cortical leakage of injured vertebra and the standard S/H ratio of injured vertebra (r=0.493, P<0.001). ConclusionThe incidence of cortical leakage of bone cement after PKP in OVCF patients is high, and cortical rupture is the basis of cortical leakage. The more severe the vertebral injury, the greater the probability of cortical leakage.
Objective To investigate the feasibility of predicting proximal junctional kyphosis (PJK) in adults after spinal deformity surgery based on back-forward Bending CT localization images and related predictive indicators. Methods A retrospective analysis was performed for 31 adult patients with spinal deformity who underwent posterior osteotomy and long-segment fusion fixation between March 2017 and March 2020. There were 5 males and 26 females with an average age of 62.5 years (range, 30-77 years). The upper instrumented vertebrae (UIV) located at T5 in 1 case, T6 in 1 case, T9 in 13 cases, T10 in 12 cases, and T11 in 4 cases. The lowest instrumented vertebrae (LIV) located at L1 in 3 cases, L2 in 3 cases, L3 in 10 cases, L4 in 7 cases, L5 in 5 cases, and S1 in 3 cases. Based on the full-length lateral X-ray film of the spine in the standing position before and after operation and back-forward Bending CT localization images before operation, the sagittal sequence of the spine was obtained, and the relevant indexes were measured, including thoracic kyphosis (TK), lumbar lordosis (LL), local kyphosis Cobb angle (LKCA) [the difference between the different positions before operation (recovery value) was calculated], kyphosis flexibility, hyperextension sagittal vertical axis (hSVA), T2-L5 hyperextension C7-vertebral sagittal offset (hC7-VSO), and pre- and post-operative proximal junctional angle (PJA). At last follow-up, the patients were divided into PJK and non-PJK groups based on PJA to determine whether they had PJK. The gender, age, body mass index (BMI), number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, osteotomy grading, and related imaging indicators were compared between the two groups. The hC7-VSO of the vertebral body with significant differences between groups was taken, and the receiver operating characteristic curve (ROC) was used to evaluate its accuracy in predicting the occurrence of PJK. Results All 31 patients were followed up 13-52 months, with an average of 30.0 months. The patient’s PJA was 1.4°-29.0° at last follow-up, with an average of 10.4°; PJK occurred in 8 cases (25.8%). There was no significant difference in gender, age, BMI, number of fusion segments, number of cases with coronal plane deformity, bone mineral density (T value), UIV position, LIV position, operation time, intraoperative blood loss, and osteotomy grading between the two groups (P>0.05). Imaging measurements showed that the LL recovery value and T8-L3 vertebral hC7-VSO in the PJK group were significantly higher than those in the non-PJK group (P>0.05). There was no significant difference in hyperextension TK, hyperextension LL, hyperextension LKCA, TK recovery value, LL recovery value, kyphosis flexibility, hSVA, and T2-T7, L4, L5 vertebral hC7-VSO (P>0.05). T8-L3 vertebral hC7-VSO was analyzed for ROC curve, and combined with the area under curve and the comprehensive evaluation of sensitivity and specificity, the best predictive index was hC7-L2, the cut-off value was 2.54 cm, the sensitivity was 100%, and the specificity was 60.9%. Conclusion Preoperative back-forward Bending CT localization image can be used to predict the occurrence of PJK after posterior osteotomy and long-segment fusion fixation in adult spinal deformity. If the patient’s T8-L2 vertebral hC7-VSO is too large, it indicates a higher risk of postoperative PJK. The best predictive index is hC7-L2, and the cut-off value is 2.54 cm.
Objective To investigate the imaging characteristics of cervical kyphosis and spinal cord compression in cervical spondylotic myelopathy (CSM) with cervical kyphosis and the influence on effectiveness. Methods The clinical data of 36 patients with single-segment CSM with cervical kyphosis who were admitted between January 2020 and December 2022 and met the selection criteria were retrospectively analyzed. The patients were divided into 3 groups according to the positional relationship between the kyphosis focal on cervical spine X-ray film and the spinal cord compression point on MRI: the same group (group A, 20 cases, both points were in the same position), the adjacent group (group B, 10 cases, both points were located adjacent to each other), and the separated group (group C, 6 cases, both points were located >1 vertebra away from each other). There was no significant difference between groups (P>0.05) in baseline data such as gender, age, body mass index, lesion segment, disease duration, and preoperative C2-7 angle, C2-7 sagittal vertical axis (C2-7 SVA), C7 slope (C7S), kyphotic Cobb angle, fusion segment height, and Japanese Orthopedic Association (JOA) score. The patients underwent single-segment anterior cervical discectomy with fusion (ACDF). The occurrence of postoperative complications was recorded; preoperatively and at last follow-up, the patients’ neurological function was evaluated using the JOA score, and the sagittal parameters (C2-7 angle, C2-7 SVA, C7S, kyphotic Cobb angle, and height of the fused segments) were measured on cervical spine X-ray films and MRI and the correction rate of the cervical kyphosis was calculated; the correlation between changes in cervical sagittal parameters before and after operation and the JOA score improvement rate was analyzed using Pearson correlation analysis. Results In 36 patients, only 1 case of dysphagia occurred in group A, and the dysphagia symptoms disappeared at 3 days after operation, and the remaining patients had no surgery-related complications during the hospitalization. All patients were followed up 12-42 months, with a mean of 20.1 months; the difference in follow-up time between the groups was not significant (P>0.05). At last follow-up, all the imaging indicators and JOA scores of patients in the 3 groups were significantly improved when compared with preoperative ones (P<0.05). The correction rate of cervical kyphosis in group A was significantly better than that in group C, and the improvement rate of JOA score was significantly better than that in groups B and C, all showing significant differences (P<0.05), and there was no significant difference between the other groups (P>0.05). The correlation analysis showed that the improvement rate of JOA score was negatively correlated with C2-7 angle and kyphotic Cobb angle at last follow-up (r=−0.424, P=0.010; r=−0.573, P<0.001), and positively correlated with the C7S and correction rate of cervical kyphosis at last follow-up (r=0.336, P=0.045; r=0.587, P<0.001), and no correlation with the remaining indicators (P>0.05). Conclusion There are three main positional relationships between the cervical kyphosis focal and the spinal cord compression point on imaging, and they have different impacts on the effectiveness and sagittal parameters after ACDF, and those with the same position cervical kyphosis focal and spinal cord compression point have the best improvement in effectiveness and sagittal parameters.