Equivalent values between anterior vertebral height, wedge ratio, and wedge angle for evaluating vertebral mobility and deformity in osteoporotic vertebral fractures: a conventional observational study.

BACKGROUND: Vertebral mobility (V-mobility) has been used to diagnose fresh osteoporotic vertebral fractures (OVFs) and determine bone union by setting cutoff values for these purposes. V-mobility is the difference in vertebral height on dynamic radiographs taken in the sitting and lateral decubitus or supine positions. The dimensions for V-mobility were presented as anterior vertebral height (Ha; mm), wedge ratio (WR; %), and wedge angle (WA; °) in previous reports. This study was performed to obtain WR and WA values equivalent to V-mobility of 1.0 mm in Ha. METHODS: Lateral radiographs of 284 OVFs (grade 1-3 deformed vertebrae) from T11 to L2 were obtained from 77 patients with OVF. V-mobility presented as Ha, posterior vertebral height, and WA was obtained by the difference in these dimensions on dynamic radiographs. The WR and WA values equivalent to 1.0 mm in Ha were obtained by dividing the V-mobility values for WR and WA by that for Ha. RESULTS: The mean WR values corresponding to 1.0 mm in Ha for grade 1, 2, and 3 vertebrae were 3.2% ± 1.4%, 3.2% ± 0.9%, and 3.4% ± 1.0%, respectively, and the corresponding value for grade 1-3 vertebrae was 3.3% ± 1.0%. The mean WA values corresponding to 1.0 mm in Ha for grade 1, 2, and 3 vertebrae were 1.5° ± 0.8°, 1.5° ± 0.6°, and 1.5° ± 0.8°, respectively, and the corresponding value for grade 1-3 vertebrae was 1.5° ± 0.7°. CONCLUSIONS: The WR and WA values equivalent to V-mobility of 1.0 mm in Ha were 3.3% and 1.5°, respectively, in grade 1-3 vertebrae. These findings may be useful to secure a reliable value of V-mobility of OVFs using simultaneous measurements in three dimensions (Ha, WR, and WA) in clinical practice and to establish cutoff values for V-mobility to determine bone union.

Establishing a nomogram to predict refracture after percutaneous kyphoplasty by logistic regression.

Introduction: Several studies have examined the risk factors for post-percutaneous kyphoplasty (PKP) refractures and developed many clinical prognostic models. However, no prior research exists using the Random Forest (RF) model, a favored tool for model development, to predict the occurrence of new vertebral compression fractures (NVCFs). Therefore, this study aimed to investigate the risk factors for the occurrence of post-PKP fractures, compare the predictive performance of logistic regression and RF models in forecasting post-PKP fractures, and visualize the logistic regression model. Methods: We collected clinical data from 349 patients who underwent PKP treatment at our institution from January 2018 to December 2021. Lasso regression was employed to select risk factors associated with the occurrence of NVCFs. Subsequently, logistic regression and RF models were established, and their predictive capabilities were compared. Finally, a nomogram was created. Results: The variables selected using Lasso regression, including bone density, cement distribution, vertebral fracture location, preoperative vertebral height, and vertebral height restoration rate, were included in both the logistic regression and RF models. The area under the curves of the logistic regression and RF models were 0.868 and 0.786, respectively, in the training set and 0.786 and 0.599, respectively, in the validation set. Furthermore, the calibration curve of the logistic regression model also outperformed that of the RF model. Conclusion: The logistic regression model provided better predictive capabilities for identifying patients at risk for post-PKP vertebral fractures than the RF model.

Equivalent values between anterior vertebral height, wedge ratio, and wedge angle in osteoporotic vertebral fractures.

INTRODUCTION: Vertebral mobility (V-mobility) has been used to diagnose fresh osteoporotic vertebral fractures (OVFs), and determine or predict bone union by setting cutoff values for these purposes. V-mobility is defined as the difference in shape of vertebral bodies between lateral radiographs taken in weight-bearing and non-weight-bearing positions. The parameters for V-mobility have varied in previous reports among anterior vertebral height (Ha, mm), wedge ratio (WR, %), and wedge angle (WA, degrees). The present study aimed to clarify WR and WA equivalent to Ha of 1.0 mm, and to compare the reported cutoff values for V-mobility presented as Ha, WR, or WA. MATERIALS AND METHODS: Lateral radiographs of 446 normal vertebrae (grade 0) and 146 deformed vertebrae (grade 1-3) from T11 to L2 were obtained from 183 female patients aged > 60 years. WR (%) values equivalent to Ha of 1.0 mm were calculated by Ha (1.0 mm)/Hp × 100 (Hp: posterior vertebral height). Corresponding WA values were calculated by trigonometric function using vertebral dimensions. RESULTS: The mean WR values equivalent to Ha of 1.0 mm in the vertebrae from T11 to L2 were 3.2%, 3.2%, 3.5%, and 3.7% for grades 0, 1, 2, and 3, respectively, and the corresponding WA values were 1.6°, 1.6°, 1.5°, and 1.4°. CONCLUSION: The equivalent values for V-mobility presented as Ha, WR, and WA were obtained. The mean WR and WA values equivalent to Ha of 1.0 mm in grade 1-3 vertebrae were 3.5% and 1.5°, respectively.

Efficacy of a novel percutaneous pedicle screw fixation and vertebral reconstruction versus the traditional open pedicle screw fixation in the treatment of single-level thoracolumbar fracture without neurologic deficit.

Objective: The aim of this study was to compare the efficacy and safety of a novel percutaneous pedicle screw fixation and vertebral reconstruction (PPSR) vs. that of open pedicle screw fixation (OPSF) in the treatment of thoracolumbar fractures. Methods: This retrospective study enrolled 153 patients who underwent PPSR and 176 patients who received OPSF. Periprocedural characteristics, radiographic parameters, and clinical outcomes were compared between the two groups. Results: The operation duration was 93.843 ± 20.611 in PPSR group and 109.432 ± 11.903 in OPSF group; blood loss was 131.118 ± 23.673 in PPSR group and 442.163 ± 149.701 in OPSF group, incision length was 7.280 ± 1.289 in PPSR group and 14.527 ± 2.893 in OPSF group, postoperative stay was 8.732 ± 1.864 in PPSR group and 15.102 ± 2.117 in OPSF group, and total hospitalization costs were 59027.196 ± 8687.447 in PPSR group and 73144.432 ± 11747.567 in OPSF group. These results indicated that these parameters were significantly lower in PPSR compared with those in OPSF group. No significant difference was observed in the incidence of complications between the two groups. The radiographic parameters including height of the anterior vertebra, Cobb angle, and vertebral wedge angle were better in PPSR group than in OPSF group. Recovery rate of AVH was 0.449 ± 0.079 in PPSR group and 0.279 ± 0.088 in OPSF group. Analysis of clinical results revealed that during postoperative period, the VAS and ODI scores in PPSR group were lower than those in OPSF group. Conclusions: Collectively, these results indicated that PPSR more effectively restored the height of anterior vertebra and alleviated local kyphosis compared with OPSF. Moreover, the VAS and ODI scores in PPSR group were better than those of OPSF group.

Restoration of Anterior Vertebral Height by Short-Segment Pedicle Screw Fixation with Screwing of Fractured Vertebra for the Treatment of Unstable Thoracolumbar Fractures.

BACKGROUND: The treatment of unstable thoracolumbar fractures remains controversial. Long-segment pedicle screw constructs may be stiffer and impart greater forces on adjacent segments compared with short-segment constructs. Short-segment pedicle screw fixation alone may be associated with instrumentation failure. Reinforcement fractured vertebra by the placement of an additional 2 screws at fracture level may be useful in thoracolumbar fractures for restoration of anterior vertebral height. MATERIAL AND METHODS: We retrospectively analyzed 35 patients (21 males, 14 females) with unstable thoracolumbar fractures. The patients were divided into 2 groups. In group I, patients were operated with posterior approach via the use of pedicle screws fixed long (2 levels above and 1 or 2 levels below of the fractured vertebra). In group II patients, short-segment stabilization with additional screwing at fracture level was made. Immediate postoperative radiologic evaluations were done by measuring the correction and maintenance of kyphotic angle at the fracture level, Cobb angle, and height of fractured vertebra. RESULTS: Average local kyphosis angle, anterior kyphotic angle at the fracture level, and Cobb angle were not statistically significantly different in the postoperative period (P > 0.05); however, postoperative anterior height of fractured vertebra was statistically significantly different between the 2 groups (P < 0.05). CONCLUSIONS: We compared a standard long-segment construct with a short-segment construct using instrumentation of the fractured segment. Short-segment pedicle screw fixation with screwing of fractured vertebra in unstable thoracolumbar fracture levels is an effective method to restoring anterior vertebral height for the treatment of unstable thoracolumbar fractures. It also provides anterior column support.

Correlation between Progression of Compression and Bone Densiometry Index in Osteoporotic Compression Fracture of Thoracolumbar Spine

PURPOSE: To evaluate whether progression of compression correlates with bone densiometry index in patients who were treated conservatively for osteoporotic compression fracture of thoracolumbar spine. MATERIALS AND METHODS: Using the results of bone densiometry, 30 patients who were treated conservatively for osteoporotic compression fracture of thoracolumbar spine between March 2002 to March 2005 were categorized into 4 groups; above 80%, 70 to 80%, 60 to 70%, and below 60%. We compared the measurements of sagittal index and anterior vertebral height from the plain radiographs taken at the time of injury and following three consecutive months after the injury. RESULTS: Patients with lower bone densiometry index had greater amount of compression at the time of injury and more rapid progression of compression. We also found that progression of compression was lowest during the first month after injury in all groups. CONCLUSION: Patients with low bone densiometry index in osteoporotic thoracolumbar compression fracture are susceptible to more rapid progression of compression and should have early brace application and longer duration of treatment for osteoporosis.

Comparison of Uniportal and Biportal Vertebroplasty in Bone Cement Distribution and Leakage

PURPOSE: To evaluate the differences of radiological outcomes of uniportal and biportal vertebroplasty in the point of bone cement distribution and leakage. MATERIALS AND METHODS: A retrospective study reviewing the period between May 2002 and January 2006 investigated 100 vertebrae which underwent vertebroplasty and followed for more than three months by uniportal approach (55 vertebrae, group 1) and biportal approach (45 vertebrae, group 2). The operative time, the amount of bone cement injected, anterior vertebral height restoration, kyphotic angle, bone cement distribution, and bone cement leakage were evaluated. RESULTS: The amount of injected bone cement of group 1 (3.9 cc) was statistically smaller than that of group 2 (5.1 cc) (p=0.016). There were no significant differences in the operative time, anterior vertebral height restoration, kyphotic angle in both groups. The rate of bone cement distribution over 8 zones was significantly higher in group 2 than in group 1 (p=0.014). However, the rate of bone cement distribution over 7 zones and the rate of bone cement distributed on whole anterior vertebral body were not significantly different in both groups. The cement leakage was not also significantly different in both groups. CONCLUSION: Although the amount of injected bone cement was smaller in uniportal vertebroplasty, the radiological results and cement leakage were similar to biportal vertebroplasty. These findings suggest that uniportal vertebroplasty can be the operative options in osteoporotic vertebral fracture.