Subsequent Vertebral Fractures Post Cement Augmentation of the Thoracolumbar Spine: Does it Correlate With Level-specific Bone Mineral Density Scores?

Factors influencing further vertebral height loss following percutaneous vertebroplasty in osteoporotic vertebral compression fractures: A 1-year follow-up study

BACKGROUND

Osteoporotic vertebral compression fractures (OVCFs) contribute to back pain and functional limitations in older individuals, with percutaneous vertebroplasty (PVP) emerging as a minimally invasive treatment. However, further height loss post-PVP prompts investigation into contributing factors.

AIM

To investigate the factors associated with further height loss following PVP with cement augmentation in OVCF patients.

METHODS

A total of 200 OVCF patients who underwent successful PVP between January 2021 and December 2022 were included in this study. "Further height loss" during 1 year of follow-up in OVCF patients with bone edema was defined as a vertical height loss of ≥ 4 mm. The study population was divided into two groups for analysis: The "No Further Height Loss group (n = 179)" and the "Further Height Loss group (n = 21)."

RESULTS

In comparing two distinct groups of patients, significant differences existed in bone mineral density (BMD), vertebral compression degree, prevalence of intravertebral cleft (IVF), type of bone cement used, and cement distribution patterns. Results from binary univariate regression analysis revealed that lower BMD, the presence of IVF, cleft distribution of bone cement, and higher vertebral compression degree were all significantly associated with further height loss. Notably, the use of mineralized collagen modified-poly(methyl methacrylate) bone cement was associated with a significant reduction in the risk of further height loss. In multivariate regression analysis, lower BMD and the presence of IVF remained significantly associated with further height loss.

CONCLUSION

Further height loss following PVP in OVCF patients is influenced by a complex interplay of factors, especially lower BMD and the presence of IVF. These findings underscore the importance of assessing and managing these factors when addressing height loss following PVP in OVCF patients.

Early cement augmentation may be a good treatment option for pain relief for osteoporotic compression fractures: a systematic review and meta-analysis

PURPOSE

The incidence of osteoporotic compression fractures (VCFs) have been rising over the past decades. Presently, vertebral cement augmentation procedures such as balloon kyphoplasty and vertebroplasty are common treatments allowing pain relief and functional recovery. However, there is controversy on whether different timeframes for cement augmentation affects clinical outcomes. Hence, this study aimed to compare pain relief and complication rates between early versus late cement augmentation.

METHODS

A comprehensive systematic review of PubMed, EMBASE, Scopus and Cochrane Library was conducted, identifying studies that compared early versus late cement augmentation for VCFs. As the definitions of "early" and "late" phases across studies are heterogenous, we established the cut-off between early and late phase as intervals to accommodate as many studies as possible for analysis. We conducted two separate analyses with different cut-off intervals and included studies that reported interventions within these respective time intervals. In analysis 1, we included studies which grouped patients into "early" and "late" group based on a cut-off time frame of 2-4 weeks. On the other hand, in analysis 2, we included studies which grouped patients into "early" and "late" groups based on a cut-off time frame of 6-8 weeks. Meta-analysis was conducted via random-effect models, comparing outcomes of interest between early and late groups.

RESULTS

Eleven studies were included. The total cohort size was 712 and 775 patients in analysis 1 and 2 respectively. Mean follow-up was 12.9 ± 3.7 months and 11 ± 0.6 months respectively. VAS change at final follow-up was significantly greater in the early group for both analyses. (MD = - 0.66, p = 0.01; and MD = - 1.18, p < 0.005 respectively). There was no significant difference in post-operative absolute VAS score, number of cement leakage, number of adjacent compression fractures and local kyphotic angle, for both analyses. Patients in both groups experienced reductions in VAS score that exceeded the minimum clinically important difference.

CONCLUSION

Both early and late timeframes for cement augmentation offered significant improvement in pain relief, with similar post-operative absolute pain score, kyphotic angle, cement leakage and adjacent vertebral fractures. Early surgery may offer substantial pain relief in patients presenting with pain as early as < 2-4 weeks of VCFs.

Timing of symptomatic subsequent vertebral compression fracture associated with different demographic factors

BACKGROUND

Symptomatic subsequent vertebral compression fracture (VCF; SVCF) is a common complication associated with poor outcomes. Accumulating evidence shows that demographic factors and incidences of symptomatic SVCFs differ during different periods after the primary vertebroplasty (VP).

PURPOSE

To investigate the incidence and demographic factors of symptomatic SVCFs after the primary VP in different periods using registry data in the Taiwan National Health Insurance Research Database.

METHODS

This retrospective cohort study included 28,343 patients aged ≥ 50 years with painful VCF treated with VP from 2002 to 2016. Symptomatic SVCF was defined as SVCF requiring another VP or re-admission. During the 2-year follow-up, 1955 patients received subsequent VP while 1,407 were readmitted. Cox proportional hazard models were used to compare the risks of subsequent VP or readmission.

RESULTS

The cumulative incident rate of subsequent VP and re-hospitalization was 0.87 [95% confidence interval (CI), 0.82 ~ 0.92] and 0.62 (95% CI, 0.58 ~ 0.66) per 100 person-months, respectively, within the first 6 months after the primary VP, and it decreased over time. A multiple Cox regression model showed that age, osteopenia or osteoporosis, Charlson comorbidity index (CCI) were significant independent risk factors of subsequent VP or readmission within the first 6 months.

CONCLUSIONS

This study demonstrated that the incidence of symptomatic SVCF peaked in the first 6 months after the primary VP. Age, osteoporosis or osteopenia, and CCI were determined to be risk factors in the first 6 months, but only osteoporosis or osteopenia and CCI were risk factors thereafter.

Biomechanical Analysis of Different Internal Fixation Combined with Different Bone Grafting for Unstable Thoracolumbar Fractures in the Elderly

This research was developed to accurately evaluate the unstable fractures of thoracolumbar before and after surgery and discuss the treatment timing and methods. Three-dimensional (3D) finite element method was adopted to construct the T₁₂-L₅ segment model of human body. The efficiency of percutaneous kyphoplasty (PKP) and percutaneous vertebroplasty (PVP), two commonly used internal fixation procedures, was retrospectively compared. A total of 150 patients with chest fracture who received PKP or PVP surgery in our hospital, and 104 patients with the same symptoms who received conservative treatment were collected and randomly rolled into PVP group (75 cases), PKP group (75 cases), and control group (104 cases). Visual analog scale (VAS) score and Oswestry disability index (ODI) of patients were collected before and after surgery and 2, 12, and 24 months after surgery. Then, the anterior and central height of the patient's cone and the kyphosis angle were calculated by X-ray. Lumbar minimally invasive fusion system and lumbar pedicle screw rod system were established by computer-aided design (CAD), and the biomechanical characteristics were analyzed. The results showed that there was no substantial difference in VAS score and ODI score between PKP and PVP (P > 0.05), but they were higher than those of the control group (P < 0.05). The anterior edge and middle height of vertebra in the two groups were higher than those in control group (P < 0.05), and the increase in PKP group was more substantial (P < 0.05). The kyphosis of the two groups was smaller than that of the control group (P < 0.05), and the decrease of the kyphosis of the PKP group was more substantial (P < 0.05). In summary, the thoracolumbar segment model established by 3D finite element method was an effective model, and it was verified on patients that both PKP and PVP could achieve relatively satisfactory efficacy. The implantation of the new internal fixation system had no obvious effect on the lumbar movement. This work provided a novel idea and method for the treatment of senile thoracolumbar unstable fracture, as well as experimental data of biomechanics for the operation of senile unstable fracture.

Efficacy of annual zoledronic acid in initial percutaneous kyphoplasty patients with osteoporotic vertebral compression fractures: a 3-year follow-up study

This study investigated the efficacy of annual zoledronic acid (ZOL) administration against previously treated recompression vertebral fractures (RVF) and new vertebral fractures (NVF) in initial percutaneous kyphoplasty (PKP) patients with osteoporotic vertebral compression fractures (OVCF) over a 3-year follow-up period.

INTRODUCTION

Although PKP achieves a satisfactory outcome, previously treated RVF and NVF can limit its effectiveness. The annual infusion of ZOL over 3 years can improve fracture protection, particularly in the vertebrae. We hypothesized that ZOL can reduce the incidence of RVFs and/or NVFs, and improve the clinical outcomes of PKP.

METHODS

This was a placebo-controlled, double-blind prospective trial of 154 PKP patients (mean age: 70 years) with OVCFs. Patients were randomly assigned to receive a single infusion of ZOL (5 mg) or placebo (78 ZOL vs. 76 placebo) at 1 week, 12 months, and 24 months after surgery. Patients were followed-up for 36 months.

RESULTS

ZOL treatment lowered the risk of RVF by ~ 65% over the 36-month period when compared to placebo controls (6.41% in ZOL vs. 18.42% in placebo groups; relative risk, 0.35; 95% CI, 0.13 to 0.92). ZOL also reduced the risk of NVF by ~ 73% (3.85% in ZOL vs. 14.47% in placebo groups; relative risk, 0.27; 95% CI, 0.08 to 0.92). ZOL also significantly reduced the vertebral height lost rate (HLR) at 12, 24, and 36 months. ZOL also improved the visual analog scale (VAS), Oswestry disability index (ODI) scores, and bone mineral density (BMD).

CONCLUSION

Annual ZOL administration significantly lowers the risk of RVFs and NVFs, improving the clinical outcome of initial PKP in patients with OVCFs over a 3-year follow-up period.

TRIAL REGISTRATION

ChiCTR2000029307.

Teriparatide Associated with Fewer Refractures and Higher Body Heights of Cemented Vertebrae after Vertebroplasty: A Matched Cohort Study

Refracture of cemented vertebrae occurs commonly after vertebroplasty (VP) for osteoporotic vertebral compression fracture (OVCF). It can result in severe pain or neurological deficit, but no preventive medication is available. Owing to the bone anabolic benefits of teriparatide (TP), this study was aimed to compare the outcomes of cemented vertebrae with TP to those without TP. Patients who received VP for OVCF with at least 1 year follow-up were included. The anterior body height (ABH) and middle body height (MBH) and kyphotic angle (KA) were measured before VP and 1 week and at least 1 year after VP. Refracture was defined as a 15% decrease in ABH or MBH and 8° decrease in KA compared with those at postoperative 1 week. The clinical outcomes were evaluated. 35 VP procedures in 21 patients treated with TP (TP group), and, matched to that, 29 out of 133 patients treated with VP alone (VP group) were included. One year after VP, ABH and MBH were significantly greater, except KA, in the TP group (VP group vs. TP group: KA - 4.97° ± 12.1 vs. -2.85° ± 12.21°, p = 0.462, ABH 1.56 ± 0.48 cm vs. 1.84 ± 0.56 cm, p = 0.027, MBH 1.49 ± 0.39 cm vs. 1.73 ± 0.41 cm, p = 0.017). The refracture rates of KA, ABH, and MBH were significantly lower in the TP group (VP group vs. TP group: KA 42.11% vs.8.57%, p < 0.001; ABH 76.32% vs. 28.57%, p < 0.0001; MBH 76.32% vs. 28.57%, p < 0.0001). In single-level subgroup comparison, TP was associated with better improvement of pain VAS and better radiological outcomes. TP was associated with higher BHs and fewer refractures than VP alone, with comparable clinical outcomes 1 year after VP. TP may be associated with better improvement of pain VAS in those with single-level VP procedure. Higher BH was due to the better maintenance effect of TP.

A Study of Risk Factors for Early-Onset Adjacent Vertebral Fractures After Kyphoplasty

STUDY DESIGN

Retrospective study.

OBJECTIVES

To elucidate risk factors for early-onset (2 months after initial kyphoplasty) adjacent vertebral fracture (EO-AVF) after kyphoplasty.

METHODS

A total of 108 vertebral bodies (95 patients) were included in this study. We examined patient backgrounds, the spinal level of EO-AVFs, surgery-related factors, and imaging findings. We divided the cases into 2 groups: patients with EO-AVF and patients without EO-AVF. Univariate, correlation, and multivariate analyses were conducted to reveal the risks factors for EO-AVFs for these 2 groups.

RESULTS

EO-AVFs developed in 28 vertebral bodies; they did not develop in 80 vertebral bodies. The overall EO-AVF incidence rate was 26%. The spinal level was the thoracolumbar junction for 93% of patients and another level for 7%, thus demonstrating the concentration of EO-AVFs in the thoracolumbar junction. For patients without EO-AVF and those with EO-AVF, there were significant differences in age (76 and 80 years, respectively), preoperative vertebral angles (VAs) (17.8° and 23°, respectively), and corrected VAs (7.3° and 12.7°, respectively). Significant differences were not observed for other factors. Pearson's correlation coefficient was 0.661 (P < .000), thereby showing a significantly positive correlation between preoperative VAs and corrected VAs. Logistic regression analysis indicated that age (odds ratio, 1.112; 95% CI, 1.025-1.206) and preoperative VAs (odds ratio, 1.08; 95% CI, 1.026-1.135) were covariates and that the presence of an EO-AVF was a dependent variable. Therefore, both were predictable risk factors for EO-AVFs.

CONCLUSION

Age, preoperative VAs, and corrected VAs are risk factors for EO-AVFs after kyphoplasty.

12-Month Teriparatide Treatment Reduces New Vertebral Compression Fractures Incidence And Back Pain And Improves Quality Of Life After Percutaneous Kyphoplasty In Osteoporotic Women

PURPOSE

Define the effectiveness of teriparatide (TPTD) treatment on reducing the incidence of new vertebral compression fractures (NVCFs) and back pain and improving quality of life after percutaneous kyphoplasty (PKP).

METHODS

Two years of clinical follow-up data from primary osteoporotic women who had experienced initial osteoporotic vertebral compression fractures (OVCFs) and received PKP plus 12-month TPTD (n=113) or basic treatment (BT) of calcium and vitamin D supplements (n=208) were retrospectively collected. The risk of NVCFs over each 6-month period in the TPTD group was evaluated and compared with the BT group using a logistic regression. Health-related quality of life (HRQoL, EQ-5D questionnaire), back pain [100 mm visual analog scale (VAS)] and bone mineral density (BMD) of the spine were analyzed using linear mixed models for repeated measures (LMMRM).

RESULTS

Logistic regression analysis adjusting for baseline characteristics showed that patients in the TPTD group had a lower risk of NVCFs compared with those receiving BT during the final three observation intervals (6-12 months, OR=0.189, 95% CI=0.030-0.681, p=0.046; 12-18 months, OR=0.009, 95% CI=0.0001-0.111, p=0.001; 18-24 months, OR=0.024, 95% CI=0.0009-0.264, p=0.009, respectively). Significant improvements in adjusted EQ-5D and back pain VAS scores were identified in the TPTD group compared with the BT group, and this improvement was sustained for at least 12 months after teriparatide treatment was discontinued (both p<0.001). The BMD of the spine also showed a higher T-value in the TPTD group compared with the BT group (p<0.001).

CONCLUSION

In routine clinical practice, for patients with OVCFs who receive the PKP procedure, TPTD treatment may be a preferable subsequent therapy because of its ability to reduce the incidence of NVCFs and sustain a high quality of life and back pain alleviation.

Percutaneous Vertebroplasty Does Not Increase the Incidence of New Fractures in Adjacent and Nonadjacent Vertebral Bodies

STUDY DESIGN

This was a clinical retrospective study.

OBJECTIVES

This retrospective study aimed to investigate the incidence of new vertebral compression fractures (NVCFs) and analyze the risk factors that influence the secondary fractures in adjacent and nonadjacent levels after percutaneous vertebroplasty (PVP) and conservative treatment (CT).

SUMMARY OF BACKGROUND DATA

PVP is an effective procedure to alleviate the pain caused by osteoporotic vertebral compression fractures. NVCFs have been noted as a potential late sequela of the procedure. However, it remains unclear whether NVCFs are due to this augmentation or simply are the result of the natural progression of osteoporosis.

METHODS

A total of 290 patients who had undergone PVP and 270 patients who had undergone CT during the last 4 years were examined. They were followed-up on a monthly basis by telephone for >2 years. They were divided into 2 groups: NVCFs and non-NVCFs. The groups were statistically compared in terms of age, sex, body mass index, initial fracture levels, bone mineral density (BMD) score of the spine, original fracture levels, and new fracture levels.

RESULTS

After a mean follow-up of at least 24 months (range, 24-78 mo), 42 NVCFs occurred in 37 of 290 patients after PVP and 33 NVCFs in 30 of 270 patients after CT. Only BMD was significantly different between the groups. Lower BMD was a significant predictive factor for NVCFs.

CONCLUSIONS

PVP did not increase the incidence of NVCFs, especially those adjacent to the treated vertebrae, following augmentation with PVP compared with CT. The most important risk factor for NVCFs was osteoporosis.

Bracing after percutaneous vertebroplasty for thoracolumbar osteoporotic vertebral compression fractures was not effective

OBJECTIVE

The objective of this study was to evaluate the effectiveness of bracing after percutaneous vertebroplasty (PVP) for thoracolumbar osteoporotic vertebral compression fractures (OVCF).

METHODS

This is a retrospective study where we recruited 138 patients with single-level thoracolumbar OVCF who underwent PVP from January 2018 to March 2018 without bracing after PVP (Group A). The visual analog score (VAS) and vertebral body compression ratio (VCR) were recorded at preoperation, on the second day, at 2 weeks, 1 month, and 6 months after operation. Oswestry Disability Index (ODI) was recorded at preoperation, 2 weeks, 1 month, and 6 months after operation. Propensity score matching identified 138 historical patients (Group B) as controls, who used rigid brace for 3 weeks after the surgery, from January 2017 to December 2017 using six independent variables (preoperation): age, sex, VAS, ODI, bone mineral density, and body mass index. The indicators and complications were compared between the two groups.

RESULTS

Compared with preoperation, VAS and VCR were significantly improved (P<0.05) in both groups on the second day after operation. At 2 weeks, 1 month, and 6 months after PVP operation, ODI, VAS, and VCR were all significantly improved than at preoperation (P<0.05). There were no statistical differences between the two groups in VAS and VCR on the second day, at 1 month and 6 months after PVP (P<0.05). There were no significant differences between Groups A and B in ODI at 2 weeks and 6 months after operation (P<0.05) but ODI for Group B at 1 month after operation was significantly higher than Group A (P<0.05). Eleven cases in Group A and 13 cases in Group B had poor pain relief on the second day after operation, and there were no significant differences in VAS and ODI between the two subgroups at 2 weeks, 1 month, and 6 months after PVP. There were no significant differences in the collapse and refracture rates between the two groups.

CONCLUSION

In summary, in terms of quality of life and complications after operation, postoperative bracing did not result in improved outcomes. Presence or absence of bracing did not relieve postoperative residual pain. In contrast, bracing for 3 weeks after operation reduced the quality of life in the short term.

Clinical, Radiographic, and Morphometric Risk Factors for Adjacent and Remote Vertebral Compression Fractures Over a Minimum Follow-up of 4 Years After Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures: Novel Three-dimensional Voxel-Based Morphometric Analysis

OBJECTIVE

This study aimed to analyze the risk factors for secondary new vertebral compression fractures (SNVCFs) after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures.

METHODS

We evaluated the association of SNVCFs (adjacent vertebral compression fractures [AVCFs] and remote vertebral compression fractures) with clinical, radiographic, and PVP procedure-related morphologic parameters based on the data collected from 402 patients over a minimum follow-up of 4 years after PVP. Procedure-related morphologic parameters were assessed using a three-dimensional voxel-based analysis. Univariate and multivariate regression analyses were conducted.

RESULTS

On univariate analysis, bone mineral density (BMD), preoperative compression ratio, preoperative sagittal index (SI), and intradiscal bone cement leakage were significantly associated with SNVCF and AVCF (P < 0.05), whereas only BMD and preoperative SI were significantly associated with remote vertebral compression fracture (P < 0.05). A large ratio of bone cement volume to vertebral body volume and skewed bone cement distribution along the inferior-to-superior axis were especially significant risk factors for AVCF (P = 0.027 and P = 0.029, respectively). On multivariate analysis, BMD was significantly associated with SNVCF (P = 0.041), whereas upper adjacent intradiscal bone cement leakage was significantly associated with AVCF (P = 0.003).

CONCLUSIONS

Low BMD, high preoperative compression ratio, and high preoperative SI may be predictive factors for SNVCFs. In particular, to prevent AVCF, the injected bone cement should be distributed both evenly and symmetrically along the inferior-to-superior axis and the relative bone cement volume should not be excessive. Bone cement should be injected carefully to avoid upper adjacent intradiscal leakage. Prompt BMD correction is important to prevent SNVCF.

Coronal Imaging Changes Associated with Recollapse of Injured Vertebrae After Percutaneous Vertebroplasty or Percutaneous Kyphoplasty Treatment for Osteoporotic Thoracolumbar Fracture

OBJECTIVE

To observe coronal imaging changes associated with recollapse of injured vertebrae after percutaneous vertebroplasty or percutaneous kyphoplasty for osteoporotic thoracolumbar fracture (OTLF).

METHODS

Fifty-four cases were retrospectively divided into 2 groups according to the Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF) classification of thoracolumbar fracture: group A, type A1 fracture (n = 26); group B, type A3.1 fracture (n = 28). Visual analog scale, Oswestry Disability Index, local scoliotic Cobb angle, and coronal wedge angle of the injured vertebrae were observed preoperatively, on postoperative day 3, and at final follow-up.

RESULTS

The average follow-up time was 19.17 ± 6.30 months. At final follow-up, the visual analog scale score and the Oswestry Disability Index score were significantly greater in group B than in group A (both P < 0.05). At final follow-up, loss of correction of scoliotic Cobb angle and coronal wedge angle was significantly higher in group B than in group A (P < 0.05).

CONCLUSIONS

Percutaneous vertebroplasty or percutaneous kyphoplasty was effective in both type A1 and type A3.1 OTLF. However, coronal imaging changes after percutaneous vertebroplasty or percutaneous kyphoplasty were more obvious in type A3.1 OTLF than in type A1. Moreover, clinical outcomes in type A3.1 OTLF were slightly inferior to those in type A1.

Cement Distribution Patterns Are Associated with Recompression in Cemented Vertebrae After Percutaneous Vertebroplasty: A Retrospective Study

OBJECTIVE

To reevaluate the cement distribution patterns and further investigate associations between cement distribution patterns and the occurrence rates of recompression in cemented vertebrae after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures.

METHODS

Two hundred twenty-four patients with a mean age of 71.9 years were enrolled and treated with single-level PVP between June 2012 and July 2015. The mean follow-up time was 16.5 months. Data from medical records and radiographs were collected and analyzed. Cement distribution patterns were divided into 4 cement distribution patterns extending from the traditional 2 patterns: interlocked solid pattern (LS) and uninterlocked solid pattern (ULS); contiguous trabecular pattern (CT) and discontiguous trabecular pattern (DCT). Differences in treatment efficacy and the occurrence rates of recompression in cemented vertebrae were compared for both groups using the Wilcoxon rank sum test and chi-squared test.

RESULTS

Thirty-seven patients who underwent PVP developed recompression in cemented vertebrae. Recompression in cemented vertebrae was significantly more frequent in the ULS and DCT groups than in the LS and CT groups (P < 0.05 or 0.001), with the Visual Analogue Scale score at the time of final follow-up was also significantly higher in the ULS and DCT groups (P < 0.001).

CONCLUSIONS

Significant associations were found between cement distribution patterns and recompression in cemented vertebrae, which affected the clinical outcome in patients after PVP. A higher incidence of recompression in cemented vertebrae was seen in patients with treated vertebrae exhibiting ULS pattern or DCT pattern.

Polymethylmethacrylate distribution is associated with recompression after vertebroplasty or kyphoplasty for osteoporotic vertebral compression fractures: A retrospective study

BACKGROUND

Osteoporotic vertebral compression fracture, always accompanied with pain and height loss of vertebral body, has a significant negative impact on life quality of patients. Vertebroplasty or kyphoplasty is minimal invasive techniques to reconstruct the vertebral height and prevent further collapse of the fractured vertebrae by injecting polymethylmethacrylate into vertebral body. However, recompression of polymethylmethacrylate augmented vertebrae with significant vertebral height loss and aggressive local kyphotic was observed frequently after VP or KP. The purpose of this study was to investigate the effect of polymethylmethacrylate distribution on recompression of the vertebral body after vertebroplasty or kyphoplasty surgery for osteoporotic vertebral compression fracture.

METHODS

A total of 281 patients who were diagnosed with vertebral compression fracture (T5-L5) from June 2014 to June 2016 and underwent vertebroplasty or kyphoplasty by polymethylmethacrylate were retrospectively analyzed. The X-ray films at 1 day and 12 months after surgery were compared to evaluate the recompression of operated vertebral body. Patients were divided into those without recompression (non-recompression group) and those with recompression (recompression group). Polymethylmethacrylate distribution pattern, including location and relationship to endplates, was compared between the two groups by lateral X-ray film. Multivariate logistic regression analysis was performed to assess the potential risk factors associated with polymethylmethacrylate distribution for recompression.

RESULTS

One hundred and six (37.7%) patients experienced recompression after surgery during the follow-up period. The polymethylmethacrylate distributed in the middle of vertebral body showed significant differences between two groups. In non-recompression group, the polymethylmethacrylate in the middle portion of vertebral body were closer to endplates than that in the recompression group (upper: t = 31.41, p<0.001; lower: t = 12.19, p<0.001). The higher percentage of the height of polymethylmethacrylate in the middle portion of vertebral body indicates the lower risk of recompression (odds ratio [OR]<0.01, p<0.001). The recompression group and non-recompression group showed significant difference in "contacted" polymethylmethacrylate distribution pattern (polymethylmethacrylate contacted to the both upper/lower endplates) (χ2 = 66.23, p<0.001). The vertebra with a "contacted" polymethylmethacrylate distribution pattern has lower risk of recompression (OR = 0.09, p<0.001).

CONCLUSIONS

Either more polymethylmethacrylate in the middle portion of vertebral body or "contacted" polymethylmethacrylate distribution pattern had a significantly less incidence of recompression. The findings indicated that the control of polymethylmethacrylate distribution during surgery may reduce the risks of recompression after vertebroplasty or kyphoplasty.

Non neurologic burst thoracolumbar fractures fixation: Case-control study

STUDY DESIGN

Burst fractures not associated with any neurological deficits are frequent but not therapeutic agreement on their management is available to date. This case-control study was conducted to try to help guide therapeutic decision in the treatment of such fractures.

MATERIALS AND METHODS

This case-control study includes consecutive retrospective evaluation of 25 case-patients treated by posterior short-segment fixation associated with kyphoplasty (SFK) in the treatment of A3 thoracolumbar unstable fractures, as compared to a control-group composed of 82 patients treated by long-segment (LF) pedicle screws.

RESULTS

SFK patients bled significantly less than the LF patients (p=0.04). Assessment of deformation progression, vertebral height restoration and reduction of the regional kyphotic angle in the SFK and LF groups revealed no statistically significant superiority of one approach on another. In contrast, the height of endplates was significantly increased in the SFK group (p=0.006). The patients' pain levels were significantly improved in the SFK group (p=0.002). However, patients from the SFK group stood earlier postoperatively (1.7 vs 3.7days, p=0.001).

CONCLUSION

We believe that SFK in vertebral fractures is as efficient as LF for bone consolidation and spine stabilization. In addition, SFK patients may use fewer analgesics.