Radiographic adjacent segment degeneration and risk factors for osteoporotic vertebral compression fractures treated with percutaneous kyphoplasty

Vertebral CT Hounsfield units in postmenopausal women with osteoporotic vertebral compression fracture: identification and validation of reference intervals

PURPOSE

Based on the population of postmenopausal women with osteoporotic vertebral compression fractures (OVCFs), this study aimed to identify the optimal and alternative levels of vertebral CT Hounsfield units (HU) for osteoporosis and osteoporosis-related complication assessment, establish age-specific reference intervals (RIs) of HU values, and validate its quantitative predictive value for new vertebral fractures (NVFs) after percutaneous kyphoplasty (PKP).

METHODS

Consecutive postmenopausal women diagnosed with OVCFs at our department between January 2016 and August 2024 were retrospectively reviewed. The vertebral HU of T12-L2 was measured on CT images by two independent spine surgeons twice, with a 2-week interval. The segmental average HU was assessed in terms of the representativeness of overall osteoporotic status, reproducibility, and association with clinical outcomes to identify the optimal and alternative levels. Age-specific RIs were built using the indirect Hoffmann method. The associations between HU and NVFs were assessed by correlation, receiver operator characteristic (ROC) curve, and multivariate analyses.

RESULTS

A total of 922 patients were enrolled in the optimal level identification and RI establishment study. Intraclass correlation coefficient (ICC) between segmental and average HU values was the highest at L1 (ICC, 0.970), followed by T12 (ICC, 0.955) and L2 (ICC, 0.955) in the whole population. The age-specific RIs determined in postmenopausal women with primary OVCFs were 39.22-170.92 HU (56-65 years), 21.23-132.48 HU (66-75 years), and 11.15-108.85 HU (> 75 years) at T12; 37.25-156.46 HU (56-65 years), 17.83-123.68 HU (66-75 years), and 10.71-103.59 HU (> 75 years) at L1; and 30.88-148.28 HU (56-65 years), 9.61-121.00 HU (66-75 years), and - 1.67 to 99.65 HU (> 75 years) at L2. Significant weak negative correlations were found between NVFs and average/segmental HU value (Spearman r, - 0.146 to - 0.245, P < 0.05), and risks of nonadjacent NVFs, fracture cascade, and overall NVFs after PKP increased in the individuals with decreases in HU (particularly at L1).

CONCLUSION

This study identified the optimal and alternative levels of CT HU value in postmenopausal women with OVCFs and established its corresponding age-specific RIs. Furthermore, we validated that low HU value posed high risks of NVFs after PKP and quantitatively clarified the dynamic trend of their association. This study may provide inspiration and a novel methodological approach for further research on osteoporotic diseases.

Reference intervals of adjacent disc height in fresh osteoporotic vertebral compression fractures and the association with postoperative adjacent segment complications: a quantitative study in Chinese postmenopausal women

BACKGROUND

Preoperative adjacent disc height (DH) was found as an independent risk factor for adjacent segment degeneration (ASD) after percutaneous kyphoplasty (PKP), indicating the preoperative status of the adjacent intervertebral discs may be closely related to adjacent segment complications. To establish the reference intervals (RIs) for adjacent DH of fresh osteoporotic vertebral compression fracture (OVCF) in Chinese postmenopausal women, and investigate the association with adjacent segment complications after PKP.

METHODS

Consecutive inpatients diagnosed with fresh OVCF between November 2015 and August 2023 were reviewed. The enrolled patients were divided into subgroups based on injured vertebral level; then, the cranial and caudal DH were measured. The characteristics of DH among subgroups were identified, and specific RIs were established using the indirect Hoffmann method. The associations between DH and adjacent segment complications were assessed using multivariate analysis.

RESULTS

The DH of the cranial disc was significantly lower than the corresponding caudal disc in all vertebral levels, which showed an increasing trend from T11 to L4. The RIs of DH were as follows: T11 (cranial), 2.14-5.14 mm; T11 (caudal), 2.64-5.89 mm; T12 (cranial), 2.69-5.77 mm; T12 (caudal), 3.18-6.57 mm; L1 (cranial), 3.05-6.59 mm; L1 (caudal), 3.40-8.29 mm; L2 (cranial), 3.68-8.36 mm; L2 (caudal), 4.57-9.78 mm; L3 (cranial), 4.53-8.92 mm; L3 (caudal), 5.26-10.07 mm; L4 (cranial), 4.70-11.42 mm; and L4 (caudal), 5.52-12.12 mm. Increased risks of adjacent segment complications after PKP were observed in patients with decreased adjacent DH.

CONCLUSION

The estimated vertebral level and disc level-specific RIs for adjacent DH of fresh OVCF were established in the Chinese postmenopausal women population. A decrease in adjacent DH posed high risks of adjacent segment complications after PKP for treating OVCF.

Deep learning-based multimodal image analysis predicts bone cement leakage during percutaneous kyphoplasty: protocol for model development, and validation by prospective and external datasets

Background

Bone cement leakage (BCL) is one of the most prevalent complications of percutaneous kyphoplasty (PKP) for treating osteoporotic vertebral compression fracture (OVCF), which may result in severe secondary complications and poor outcomes. Previous studies employed several traditional machine learning (ML) models to predict BCL preoperatively, but effective and intelligent methods to bridge the distance between current models and real-life clinical applications remain lacking.

Methods

We will develop a deep learning (DL)-based prediction model that directly analyzes preoperative computed tomography (CT) and magnetic resonance imaging (MRI) of patients with OVCF to accurately predict BCL occurrence and classification during PKP. This retrospective study includes a retrospective internal dataset for DL model training and validation, a prospective internal dataset, and a cross-center external dataset for model testing. We will evaluate not only model's predictive performance, but also its reliability by calculating its consistency with reference standards and comparing it with that of clinician prediction.

Discussion

The model holds an imperative clinical significance. Clinicians can formulate more targeted treatment strategies to minimize the incidence of BCL, thereby improving clinical outcomes by preoperatively identifying patients at high risk for each BCL subtype. In particular, the model holds great potential to be extended and applied in remote areas where medical resources are relatively scarce so that more patients can benefit from quality perioperative evaluation and management strategies. Moreover, the model will efficiently promote information sharing and decision-making between clinicians and patients, thereby increasing the overall quality of healthcare services.

The Use of Spiral Cement Injector for Percutaneous Vertebroplasty to Treat Kümmell Disease: A Retrospective Study

BACKGROUND

Percutaneous vertebroplasty (PVP) is a common method used to treat Kümmell disease. In patients without neurologic symptoms, we sought to evaluate whether using the new spiral injectors instead of the traditional push-rod injectors in PVP can result in improved clinical efficacy for the treatment of Kümmell disease.

METHODS

A clinical retrospective study was conducted between August 2018 and December 2020. The study included patients diagnosed with single-level thoracolumbar Kümmell disease who underwent PVP surgery. The patients were divided into 2 groups: an observation group consisting of 53 patients treated with spiral injectors and a control group consisting of 68 patients treated with push-rod injectors.

RESULTS

A 2-year follow-up period was adopted. The bone cement injection volume and occurrence of bone cement leakage were significantly greater in the observation group compared with the control group (P < 0.05). The observation group had significantly shorter operation time and intraoperative fluoroscopy times compared with the control group (P < 0.05). The scores for the visual analog scale and Oswestry Disability Index in both groups were significantly lower at 3 days or 3 months and 2 years after surgery compared with before surgery, with the scores at 2 years after surgery being significantly lower than those at 3 days or 3 months for both groups (P < 0.05). The relative anterior ledge height and Cobb angle showed significant improvement at 3 days and 2 years after surgery compared with before surgery in both groups (P < 0.05), but patients in the observation group experienced substantial improvement at 3 days and 2 years after surgery compared with those in the control group (P < 0.05). In both groups, the relative anterior ledge height was noticeably lower 2 years after surgery compared with 3 days after surgery (P < 0.05). Concurrently, there was a significant increase in the local Cobb angle over time in both groups (P < 0.05).

CONCLUSIONS

The implementation of both spiral injectors and traditional push-rod injectors in PVP surgery yields effective pain relief, improved function, partially restored vertebral height, and corrected kyphosis in treating Kümmell disease. Compared with the push-rod injector, the spiral injector is highly efficient in restoring vertebral height, correcting kyphosis, and minimizing fluoroscopy use and operation time, but it carries a greater risk of bone cement leakage.

Clinical efficacy and influencing factors of percutaneous kyphoplasty for osteoporotic vertebral compression fractures: a 10-year follow-up study

BACKGROUND

To date, few reports have evaluated the long-term outcome of percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs) and the factors influencing the long-term outcome of this procedure are uncertain.

METHODS

A total of 91 patients underwent PKP for thoracolumbar OVCFs from June 2012 to December 2012. Pain Visual Analogue Scores (VAS) and Oswestry Disability Index (ODI) were recorded preoperatively and after 10-year follow-up. Factors that may affect surgical outcome, such as gender, age, height, weight, hypertension, diabetes, cause of injury, fracture segment, length of hospitalization, history of previous spinal surgery, preoperative bone mineral density (BMD), preoperative VAS and ODI scores, length of surgery, bone cement dosage, postoperative standardized anti-osteoporosis treatment, and other new vertebral fractures, were analyzed by multiple linear regression with VAS and ODI scores at the last follow-up. The correlation factors affecting the efficacy were analyzed.

RESULTS

The preoperative and final follow-up pain VAS was 7.9 ± 1.1 and 2.2 ± 1.1. ODI scores were 30.4 ± 4.2 and 10.7 ± 2.6. The difference was statistically significant (P < 0.05). Most of the patients were females aged 65-75 years who suffered low-energy injuries, with most of the fracture segments in the thoracolumbar region (T11-L2). At the final follow-up visit, 12 cases (13.19%) developed other new vertebral fractures, and 33 cases (36.26%) continued to adhere to anti-osteoporosis treatment after discharge. Multiple linear regression analysis showed that there was a statistical difference between gender and VAS score at the last follow-up (P < 0.05), and between age, cause of injury and postoperative standardized anti-osteoporosis treatment and ODI at the last follow-up (P < 0.05). There were no statistically significant differences between the other factors and the final follow-up VAS and ODI scores (P > 0.05).

CONCLUSION

The long-term outcome after PKP is satisfactory. Age, gender, cause of injury, and standardized postoperative anti-osteoporosis treatment may be factors affecting the long-term outcome.

Effect of bone cement distribution on adjacent disc degeneration after vertebral augmentation for osteoporotic vertebral compression fractures in aging patients

Background

The influence of vertebral augmentation on adjacent intervertebral discs remains controversial. The purpose of this study is to evaluate the effect of bone cement distribution on adjacent disc degeneration after vertebral augmentation for osteoporotic vertebral compression fractures (OVCFs).

Methods

Patients with single level OVCF and upper endplate injury who underwent vertebral augmentation were enrolled. The patients were divided into four groups: Group A: bone cement contacted both the cranial and the distal endplates; Group B: bone cement only contacted the cranial endplate; Group C: bone cement only contacted the distal endplate; and Group D: bone cement contacted neither the cranial nor the distal endplates. The cranial discs of the fractured vertebrae were defined as adjacent discs and the upper discs proximally to the adjacent discs were defined as control discs. Degenerative disc change (DDC) was defined as a deteriorated postoperative Pfirrmann score compared with the preoperative score on MR images. The number of DDC cases and the disc heights were analyzed among the groups.

Results

A total of 184 patients with an average follow-up time of 28.6 months were included. The number of DDC cases in the adjacent discs was significantly higher than in the control discs in groups A (p < 0.001), B (p = 0.002), and D (p = 0.028), whereas the difference in group C was not statistically significant (p = 0.237). The incidence of adjacent disc degeneration was significantly higher in group A than that in group C (p = 0.06). The adjacent disc heights decreased significantly in groups A, B, and D (p < 0.001, p < 0.001, and p = 0.012, respectively), but did not decrease significantly in group C (p = 0.079). However, no statistical differences were detected among the four groups with respect to the preoperative adjacent disc height, follow-up adjacent disc height, preoperative control disc height, or follow-up control disc height.

Conclusion

Bone cement distribution influences adjacent disc degeneration after vertebral augmentation in OVCFs. Cement distribution proximal to the injured endplate can accelerate adjacent disc degeneration, and cement in contact with both the cranial and distal endplates can induce a higher incidence of adjacent disc degeneration.