Risk factors of recompression of cemented vertebrae after kyphoplasty for osteoporotic vertebral compression fractures

The Influence of Percutaneous Vertebral Augmentation Techniques on Recompression in Patients with Osteoporotic Vertebral Compression Fractures. Percutaneous Vertebroplasty versus Balloon Kyphoplasty

OBJECTIVE

The purpose of this study was to determine whether percutaneous vertebroplasty (PVP) and balloon kyphoplasty (BK) have any mid-term to long-term effects on the structural integrity of augmented vertebrae.

METHODS

According to our hospital records, 351 patients underwent BK and PVP as a result of osteoporotic vertebral compression fractures between 2010 and 2020. The demographic, surgical, and radiologic characteristics of the patients were analyzed retrospectively using the electronic hospital records and PACS (picture archiving and communication system). In our study, 55 patients who had a single level of PVP or BK filled with at least 6 mL og polymethylmethacrylate (PMMA) for T11-L5 levels and 3 mL of PMMA for T6-T10 levels via a bipedicular approach and who had only 1 vertebral fracture in a 10-year follow-up period were included in our study. The patients were divided into 2 groups: BK (n = 40) and PVP (n = 15). All measurements were performed on standing lateral radiographs from the postoperative first day and the last radiographs that were obtained during the follow-up. The anterior and posterior heights of the fractured vertebral body and local kyphosis angles were measured.

RESULTS

The mean follow-up time was 2.53 ± 1.78 years in the BK group and 3.07 ± 2.02 years in the PVP group. The decrease in the vertebral height and increasing kyphosis that develop from the early to late postoperative periods were found to be statistically significant in the BK group (P < 0.05). In the PVP group, vertebral height and kyphosis angle measurements did not differ significantly between the early and late postoperative periods. In addition, in terms of the percentage change, anterior parts of the vertebral bodies are more affected. However, the absolute difference for the measurement of the vertebral heights did not confirm this finding.

CONCLUSIONS

To our knowledge, our study is unique because it has the longest follow-up in the literature comparing BK and PVP in terms of recollapse of the augmented vertebrae. Our study shows that BK does not prevent height loss of the augmented vertebral bodies in the mid- to long term.

Effects of distribution of bone cement on clinical efficacy and secondary fracture after percutaneous kyphoplasty for osteoporotic vertebral compression fractures

Objective

To investigate the effect of bilateral bone cement distribution on the clinical efficacy of percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral compression fracture (OVCF).

Methods

According to strict inclusion and exclusion criteria, 109 cases of OVCF patients treated with bipedicular PKP were included in this study from August 2018 to July 2020. According to the distribution morphology of bilateral bone cement in vertebral body, patients were divided into 3 groups, including Group A (n = 44): bilateral diffuse type; Group B (n = 31): bilateral dense type; Group C (n = 34): mixed type. To assess the clinical and radiographic efficacy of the surgery, the visual analogue scale (VAS) score, Oswestry disability index (ODI) score, anterior vertebral height (AVH), anterior vertebral height ratio (AVHR) and local kyphotic angle (LKA) were recorded at preoperatively, 2 days after surgery and 1 year after surgery.

Results

Compared with the preoperative recorded value, the VAS score, ODI score, AVH, AVHR and LKA of the three groups were significantly improved at 2 days after surgery and 1 year after surgery (p < 0.05). At 1 year after surgery, the VAS score of Group A was better than that of groups B and C (p < 0.05), and there were significantly differences in ODI score, AVH, and LKA between Group A and Group B (p < 0.05). Compared with other bone cement distribution patterns, the incidence of recompression in bilateral diffuse bone cement distribution pattern was lower (p < 0.05).

Conclusion

In the mid-term follow-up of patients undergoing bipedicular PKP, diffuse and symmetrical distribution of bone cement can obtain better clinical improvement and lower the incidence of secondary compression.

Risk factors for new vertebral compression fracture after kyphoplasty and efficacy of osteoporosis treatment: A STROBE-compliant retrospective study

Kyphoplasty (KP) has been widely used to treat vertebral compression fractures (VCFs). However, the issue of new VCFs after KP remains controversial. Identification of risk factors for new VCF after KP may help prevent their occurrence in patients. This study aimed to retrospectively determine the major risk factors for new VCF after KP, including those associated with osteoporosis drugs used after kyphoplasty. We reviewed 117 patients who underwent single-level KP. During the follow-up period of 1 year after KP, the demographic data of these patients were compared by dividing them into two groups: those with new fractures (n = 19) and those without new fractures (n = 98). We investigated the age, sex, fracture location, medical history, steroid use history, bone mineral density (BMD), type of osteoporosis treatment, period from fracture to KP, KP method (unilateral or bilateral), bone cement dose, intradiscal cement leakage, preoperative and postoperative compression ratio, kyphotic angle (KA), and lowest vertebral body height in the fractured vertebrae. Based on these data, the factors related to new VCFs after KP were investigated using univariate and multivariate logistic regression analyses. We also investigated whether there were differences in new VCFs according to the type of osteoporosis treatment. During the 1-year follow-up period after KP, the rate of new VCFs was 16.2%. Factors related to new VCFs were BMD, intradiscal cement leakage, KA recovery rate after 1 day, and baseline height in the univariate and multivariate logistic regression analyses. The group treated with zoledronate after KP tended to show a lower frequency of developing new VCFs than the groups treated with alendronate (P = .07), calcium (P = .05), selective estrogen receptor modulator (SERM) (P = .15), and risendronate (P = .02). This study showed that for patients with new VCFs after KP, lower BMD, greater intradiscal cement leakage, greater KA recovery rate, and lower baseline vertebral height were likely risk factors for the development of new VCFs. Additionally, among the drugs used for the treatment of osteoporosis after KP, zoledronate tends to reduce the development of new VCFs compared with other bisphosphonates, SERMs, or calcium.

Lateral-Opening Injection Tool Used in Percutaneous Vertebroplasty to Treat Asymptomatic Osteoporotic Vertebral Burst Fractures: A Retrospective Study

OBJECTIVE

The adequate management of asymptomatic osteoporotic vertebral burst fractures (OVBFs) was still controversial. Percutaneous vertebroplasty (PVP) could achieve quick recovery with minor trauma, but there were certain safety problems by traditional bone cement injection method. Thus, the aim of this study was to assess the efficacy of lateral-opening injection tool used in PVP treating patients with asymptomatic OVBFs.

METHODS

This was a retrospective study of OVBFs treated in our institute from March 2016 to March 2020. A total of 66 patients (mean age 72.10 ± 7.98 years, with 21 men and 45 women) who were diagnosed with acute asymptomatic OVBFs with mild spinal canal compromise were treated with PVP by using a lateral-opening injection tool. Two puncture needles were simultaneously placed transpedicularly in the fractured vertebra, and the inner core was removed, and the lateral-opening injection tool was inserted. The adjustment of lateral hole was to improve the distribution height of bone cement and avoid the entry of bone cement into the posterior wall of vertebral body. Related clinical outcomes and images were assessed, including back pain (visual analog scale [VAS]), vertebral height ratio (fractured vertebral height/average adjacent nonfractured vertebral height), kyphosis Cobb angle, union of the fractured vertebral posterior wall, distribution of bone cement, surgical data, and complications.

RESULTS

The average follow-up time of all cases was 21.23 ± 9.35 months. The mean amount of bone cement was 3.28 ± 0.35 ml in the vertebrae and the mean operative time was 34.02 ± 5.23 min. There were 60 cases of bone cement that contacted the upper and lower endplates on at least one side. There was no cement leakage into the spinal canal or fracture displacement of the posterior wall of the vertebral body in all cases. The VAS scores were 3.78 ± 0.42 at 1 day postoperatively and 0.53 ± 0.40 at the last follow-up, significantly lower than 8.40 ± 0.48 preoperatively (p < 0.05). The average height ratio of anterior, middle, and posterior vertebral body after operation increased compared with that pre-operation (p < 0.05), and the postoperative kyphosis angle decreased (p < 0.05). At 6 months follow-up, there was no significant height loss of the vertebral body. Computed tomography examination 3 months postoperatively showed that the fracture of posterior vertebral wall healed well in all cases. There were seven cases of bone cement leakage without clinical symptoms and two adjacent vertebral fractures caused by falling. There were no cases of deep vein embolism, lower limb muscle atrophy, pneumonia, decubitus.

CONCLUSION

The lateral opening tool can be safely and effectively used in the PVP treatment on asymptomatic OVBFs with mild spinal canal compromise.

Association between bone turnover markers, BMD and height loss of cemented vertebrae after percutaneous vertebroplasty in patients with osteoporotic vertebral compression fractures

Introduction

Percutaneous vertebroplasty (PVP) was recently performed for treating patients with osteoporotic vertebral compression fractures (OVCF). However, recompression of cemented vertebra with significant vertebral height loss occurred in the patients after PVP was observed during the follow-up period. The purpose is to explore the risk factors among several potential predictors for the height loss of treated vertebral bodies after PVP in patients with OVCF.

Methods

A study of 93 patients who had undergone PVP between May 1, 2016, and March 1, 2019, at the Spine Center of Huadong Hospital Affiliated to Fudan University was conducted. The fractured vertebral height loss ratio ≥ 15% at final follow-up were defined as cemented vertebra recompression. The following variables were measured and collected: age, gender, body mass index (BMI), bone mineral density (BMD), volume of bone cement injected, bone cement leakage, fractured vertebra segment, contact between bone cement and endplates, serum of calcium and phosphorus, and six kinds of bone turnover markers.

Results

Mann–Whitney U test and Univariate Logistic regression analysis showed that the cemented vertebra recompression was correlated with BMD, contact between bone cement and endplates, parathyroid hormone (PTH), and 25-hydroxy vitamin D3 (25-OH-D3). Following multivariate modeling, multiple factors logistic regression elucidated that high BMD (P < 0.001, OR = 0.089) and high level of serum 25-OH-D3 (P = 0.012, OR = 0.877) were negatively correlated with the cemented vertebra recompression after PVP.

Conclusion

Decreased BMD and lower level of serum 25-OH-D3 might be two critical and significant risk factors for the height loss of cemented vertebrae after PVP.

Insufficient Augmentation of Bone Cement Causes Recompression of Augmented Vertebra after Balloon Kyphoplasty

Introduction

Balloon kyphoplasty (BKP) is one of the most frequently used clinical methods to relieve pain caused by osteoporotic vertebral compression fracture (OVCF); it can effectively improve the body height of the vertebra. However, recompression of the augmented vertebra (RAV) is often observed after BKP. This study aimed to report factors that are associated with RAV in terms of cement augmentation.

Methods

A total of 78 patients (women, 60; men, 18) were included in this study. RAV was defined as anterior vertebral height loss (VHL), between immediate postoperation and 3 or 6 months after BKP, of more than 5.0 mm. Cement augmentation ratio (CAR) was calculated as the ratio of the maximal height of polymethylmethacrylate (PMMA) to the maximal distance between both end plates. Age, gender, fracture age, CAR, presence of medication for osteoporosis, intervertebral cleft (IVC), and cement leakage were evaluated using Fisher's exact test or Mann-Whitney U test to compare between RAV and non-RAV groups. Aforementioned variables were also analyzed using multiple logistic regression test. A P<0.05 was considered statistically significant.

Results

The incidence rates for RAV at 3 and 6 months were 35.9% (28/78) and 38.5% (30/78), respectively. Age (80.1 vs 74.7) was significantly higher in the RAV group, whereas CAR (69.4% vs 77.6%) was lower in the non-RAV group. A multivariate regression analysis revealed that age (odds ratio (OR)=1.12, P=0.001) and CAR (OR=0.91, P=0.001) were independently associated with RAV.

Conclusions

RAV was observed in 38.5% of patients in this study. Older age and low CAR were independently associated with RAV. To prevent RAV, especially in the elderly, augmented PMMA should come in contact with both end plates.

Logistic regression analysis on risk factors of augmented vertebra recompression after percutaneous vertebral augmentation

Objective

To explore the high-risk factors of augmented vertebra recompression after percutaneous vertebral augmentation (PVA) in the treatment of osteoporotic vertebral compression fracture (OVCF) and analyze the correlation between these factors and augmented vertebra recompression after PVA.

Methods

A retrospective analysis was conducted on 353 patients who received PVA for a single-segment osteoporotic vertebral compression fracture from January 2017 to December 2018 in our department according to the inclusion criteria. All cases meeting the inclusion and exclusion criteria were divided into two groups: 82 patients in the recompression group and 175 patients in the non-compression group. The following covariates were reviewed: age, gender, body mass index (BMI), injured vertebral segment, bone mineral density (BMD) during follow-up, intravertebral cleft (IVC) before operation, selection of surgical methods, unilateral or bilateral puncture, volume of bone cement injected, postoperative leakage of bone cement, distribution of bone cement, contact between the bone cement and the upper or lower endplates, and anterior height of injured vertebrae before operation, after surgery, and at the last follow-up. Univariate analysis was performed on these factors, and the statistically significant factors were substituted into the logistic regression model to analyze their correlation with the augmented vertebra recompression after PVA.

Results

A total of 257 patients from 353 patients were included in this study. The follow-up time was 12–24 months, with an average of 13.5 ± 0.9 months. All the operations were successfully completed, and the pain of patients was relieved obviously after PVA. Univariate analysis showed that in the early stage after PVA, the augmented vertebra recompression was correlated with BMD, surgical methods, volume of bone cement injected, preoperative IVC, contact between bone cement and the upper or lower endplates, and recovery of anterior column height. The difference was statistically significant (P < 0.05). Among them, multiple factors logistic regression elucidated that more injected cement (P < 0.001, OR = 0.558) and high BMD (P = 0.028, OR = 0.583) were negatively correlated with the augmented vertebra recompression after PVA, which meant protective factors (B < 0). Preoperative IVC (P < 0.001, OR = 3.252) and bone cement not in contact with upper or lower endplates (P = 0.006, OR = 2.504) were risk factors for the augmented vertebra recompression after PVA. The augmented vertebra recompression after PVP was significantly less than that of PKP (P = 0.007, OR = 0.337).

Conclusions

The augmented vertebra recompression after PVA is due to the interaction of various factors, such as surgical methods, volume of bone cement injected, osteoporosis, preoperative IVC, and whether the bone cement is in contact with the upper or lower endplates.

[Effectiveness comparison of low-temperature bone cement perfusion before and after improvement in percutaneous vertebroplasty]

Objective

To discuss the safety and effectiveness of the improved technique by comparing the effects of low temperature bone cement infusion before and after the improvement in the percutaneous vertebroplasty (PVP).

Methods

The clinical data of 170 patients (184 vertebrae) with osteoporotic vertebral compression fracture who met the selection criteria between January 2016 and January 2018 were retrospectively analyzed. All patients were treated with PVP by low-temperature bone cement perfusion technology. According to the technical improvement or not, the patients were divided into two groups: the group before the technical improvement (group A, 95 cases) and the group after the technical improvement (group B, 75 cases). In group A, the patients were treated by keeping the temperature of bone cement at 0℃ and parallel puncture; in group B, the patients were treated by increasing the temperature of bone cement or reducing the time of bone cement in ice salt water and cross puncture. There was no significant difference in gender, age, disease duration, T value of bone mineral density, operative segment, and preoperative vertebral compression rate, visual analogue scale (VAS) score between the two groups ( P>0.05). CT examination was performed immediately after operation, and the leakage rate of bone cement was calculated. The amount of bone cement perfusion and the proportion of bone cement in contact with the upper and lower endplates at the same time were compared between the two groups. The vertebral compression rate was calculated and the VAS score was used to evaluate the pain before operation, at immediate after operation, and last follow-up.

Results

There was no complication such as incision infection, spinal nerve injury, or pulmonary embolism in both groups. There was no significant difference in the amount of bone cement perfusion between groups A and B ( t=0.175, P=0.861). There were 38 vertebral bodies (36.89%) in group A and 49 vertebral bodies (60.49%) in group B exposed to bone cement contacting with the upper and lower endplates at the same time, showing significant difference ( χ ²=10.132, P=0.001). Bone cement leakage occurred in 19 vertebral bodies (18.45%) in group A and 6 vertebral bodies (7.41%) in group B, also showing significant difference ( χ ²=4.706, P=0.030). The patients in group A and group B were followed up (13.3±1.2) months and (11.5±1.1) months, respectively. The vertebral compression rates of the two groups at immediate after operation were significantly lower than those before operation ( P<0.05), but the vertebral compression rate of group A at last follow-up was significantly higher than that at immediate after operation ( P<0.05), and there was no significant difference in group B between at immediate after operation and at last follow-up ( P>0.05). The VAS scores of the two groups at immediate after operation were significantly lower than those before operation ( P<0.05); but the VAS scores of group A at last follow-up were significantly higher than those at immediate after operation ( P<0.05) and there was no siginificant difference in group B ( P>0.05). There was no significant difference in VAS scores between the two groups at immediate after operation ( t=0.380, P=0.705); but at last follow-up, VAS score in group B was significantly lower than that in group A ( t=3.627, P=0.000).

Conclusion

The improved advanced low-temperature bone cement perfusion technology during PVP by increasing the viscosity of bone cement combined with cross-puncture technology, can reduce bone cement leakage, improve the distribution of bone cement in the vertebral body, and reduce the risk of vertebral collapse, and achieve better effectiveness.

Efficacy analysis of percutaneous pedicle screw fixation combined with percutaneous vertebroplasty in the treatment of osteoporotic vertebral compression fractures with kyphosis

BACKGROUND

To investigate the clinical effect of percutaneous pedicle screw fixation (PPSF) combined with percutaneous vertebroplasty (PVP) in the treatment of osteoporotic compression vertebral fracture (OVCF) of the thoracolumbar vertebra with kyphosis.

METHODS

One hundred sixty-six patients before June 2017 were retrospectively analyzed, and patients were divided into PPSF + PVP group A and PVP group B. Operative time, bone mineral density, postoperative bed time, high compression ratio, bone cement leakage rate, and bone cement dose were recorded. Comparison of vertebral anterior edge height, Cobb angle, visual analogue score (VAS), and low back pain dysfunction index (ODI) between the two groups in preoperative, postoperative 3 days, postoperative 6 months, postoperative 12 months, and postoperative 24 months, postoperative complications were observed in the two groups.

RESULTS

The operation time of group A was longer than that of group B (59.0 ± 8.6 min, 26.6 ± 5.2 min), longer postoperative bed rest time (3.3 ± 0.7 days, 1.2 ± 0.5 days), the differences were statistically significant (P < 0.01), there was no difference in the amount of bone cement between the two groups (5.4 ± 0.6 ml, 5.3 ± 0.8 ml) (P > 0.05). The height of the anterior edge and Cobb angle of the two groups recovered significantly in postoperative 3 days. The height of anterior edge (2.7 ± 0.3 cm, 2.6 ± 0.2 cm, 2.5 ± 0.7 cm; 2.3 ± 0.6 cm, 1.7 ± 0.5 cm, 1.6 ± 0.3 cm) and Cobb angle (4.9 ± 2.2, 5.5 ± 2.3, 5.7 ± 2.3; 12.4 ± 3.2, 17.2 ± 2.5, 13.2 ± 2.3) was statistically significant in postoperative 6 months, postoperative 12 months, and postoperative 24 months (P < 0.01). VAS and ODI scores of postoperative 6 months and 12 months were significantly different between the two groups (P < 0.05). Postoperative complications in group B were much higher than those in group A.

CONCLUSION

The efficacy of PVP alone was not satisfactory, and the rate of complications was high for OVCF patients with severe anterior edge compression with kyphosis. PPSF combined with PVP is recommended, the vertebral height loss was not obvious, the satisfaction was good, and the complication rate was lower during 2 years follow-up.

Vertebral Compression Fractures Treated in Acute by Instrumented Kyphoplasty: Early and Mid-Term Clinical and Radiological Results

The treatment of traumatic low-degree vertebral compression fracture remains in a wide range between functional treatment, bracing, vertebroplasty, kyphoplasty, and even surgical fixation. The objective was to assess the innovation of instrumented kyphoplasty and to report the early and mid-term functional and radiological results. This study is a retrospective review of patients enrolled from 2012 to 2017. 104 consecutive endovertebral implantations of instrumented kyphoplasty were reviewed for the study. There were 56 women and 48 men. 93 of 104 patients were evaluated, of whom 27 were evaluated only by retrospective medical record review and 66 with follow-up visit. Clinical parameters were the pain rating scale (VAS) and the Oswestry score questionnaire. The radiological parameters were the vertebral kyphosis, vertebral height, lumbar lordosis, and adjacent disc degeneration (UCLA scale). Statistical correlations between before/after surgery/last follow-up were performed. The average follow-up was 26.7 months (3 to 55). The average VAS decreased from 8.2 to 3.2 the day after surgery, allowing immediate standup. The average Oswestry score was 14.6 at follow-up. The average vertebral kyphosis decreased from 12.9° to 6.5° post-op and stabilized at 8.0° at the last follow-up, corresponding to 28% gain on vertebral height. The lumbar lordosis was restored (+6.6°). Adjacent disc degeneration increased by 1 UCLA grade in 17 patients (16.3%) at follow-up. The instrumented kyphoplasty in acute led to immediate and lasting pain relief, with no bracing or bed rest, short stay in hospital, and quick return to daily life including professional activities. The good clinical results were associated to a stable radiological restoration of the vertebral anatomy.

Risk factor analysis for re-collapse of cemented vertebrae after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP)

PURPOSE

Re-collapse of cemented vertebrae occasionally occurs after percutaneous augmentation. However, the potential risks still remain unclear. Several articles have reported some possible risk factors which were not consistent or comprehensive. This study aimed to make a retrospective review on patients with osteoporotic vertebral compression fracture (OVCF) after percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) and to further analyse the risk factors for treated vertebral refracture.

METHODS

All patients receiving the PKP/PVP with bilateral approach were retrospectively reviewed from January 2014 to January 2016, among whom 230 patients with single level augmentation (30 in refracture group and 200 in the non-refracture group) were enrolled according to inclusion criteria. The following covariates were reviewed: gender, age, height, weight, body mass index (BMI), bone mineral density (BMD), serum bone turnover markers, surgical parameters including approach, cement volume, anterior height, and Cobb angle restoration. Binary logistic regression analysis was used to determine the relative risk of re-collapse of cemented vertebrae.

RESULTS

Regarding the patient data, weight, BMI, and BMD were of statistical significance in refracture group (P < 0.01), among which only low BMD was a risk factor to cemented vertebral re-collapse (P = 0.022, OR = 4.197). In respect of surgical variables, the better restoration of anterior height and Cobb angle was found in refracture group (P < 0.05), both of which might increase the refracture risk but not be risk factors (P = 0.065, OR = 0.891, and P = 0.937, OR = 0.996, respectively). Besides, less injected cement (3.30 ± 0.84 ml vs 4.46 ± 1.10 ml, P = 0.000, OR = 19.433) and PKP (P = 0.007, OR = 13.332) significantly boosted the potential risk of refracture (P < 0.001).

CONCLUSION

Patients with low BMD, or undergoing PKP, or receiving a low volume of injected cement might have a high risk of re-collapse in surgical vertebrae.

Risk Factors for Recollapse of the Augmented Vertebrae After Percutaneous Vertebral Augmentation: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Recollapse of the augmented vertebrae after percutaneous vertebral augmentation treatment for osteoporotic vertebral compression fractures has obtained much attention. Although many potential risk factors have been proposed, they are still disputed. The aim of our study was to identify the characteristics of the augmented vertebrae that had undergone a recollapse according to a systematic review from the earliest available records up to August 2017 and then conduct a meta-analysis based on eligible studies to assess significant potential risk factors for recollapse of the augmented vertebrae.

METHODS

Fourteen studies were identified for investigating recollapse of the augmented vertebrae. Of those studies, 9 studies were eligible for meta-analysis.

RESULTS

Pooled results showed that 5 primary factors were associated with recollapse of the augmented vertebrae, including preoperative intravertebral cleft, the affected vertebrae in the thoracolumbar region, preoperative severe kyphotic deformity, solid lump cement distribution pattern, and higher vertebral height restoration. It was possibly another risk factor that the distance between PMMA and superior end plate was relatively large.

CONCLUSIONS

Careful observation of patients with these risk factors and reasonable intervention could be useful to prevent deterioration of their clinical course.

[Application of improved injecting tube in percutaneous kyphoplasty through unipedicular puncturing]

Objective

To research the feasibility and effectiveness of percutaneous kyphoplasty (PKP) by improved injecting tube through unipedicular puncturing.

Methods

Between January 2012 and Junuary 2016, 60 cases (68 vertebrae) of osteoporotic vertebral compression fractures (OVCF) were treated. PKP was performed through unipedicular puncturing with routine injecting tube in 30 cases (34 vertebrae, routine group), and with improved injecting tube in 30 cases (34 vertebrae, improved group). There was no significant difference in age, gender, disease duration, fracture level, preoperative visual analogue scale (VAS), or vertebral height between 2 groups ( P>0.05). The operation time, the volume of bone cement injected, preoperative and postoperative VAS, and preoperative and postoperative vertebral height, and postoperative distribution coefficient of bone cement were recorded and compared between 2 groups.

Results

Good healing of puncture points was achieved in 2 groups after PKP, and no serious complication occurred. There was no significant difference in operation time and the volum of bone cement injected between 2 groups ( t=0.851, P=0.399; t=1.672, P=0.101). Bone cement leakage was observed in 2 cases of 2 groups respectively. The distribution coefficient of bone cement in routine group was significantly less than that in improved group ( t=13.049, P=0.000). All patients were followed up 12-36 months (mean, 19 months). The postoperative VAS and vertebral height were significantly improved when compared with preoperative ones in 2 groups ( P<0.05), but there was no significant difference in VAS between at 2 days after operation and at last follow-up, in vertebral height between at 2 days after operation and at 1 year after operation, and between 2 groups after operation ( P>0.05). X-ray films showed vertebral compression fractures in 6 cases of routine group and in 1 case of improved group during follow-up.

Conclusion

PKP by improved injecting tube through unipedicular puncturing can improve the distribution of bone cement, restore the height and strength of vertebral body, and reduce the incidence of re-fracture.