Back to the future in traumatic fracture shapes of lumbar spine: An analysis of risk of kyphosis after conservative treatment

Sagittal Spinopelvic Alignment in the Standing and Prone Positions of Patients with Old Traumatic Thoracolumbar Kyphosis: Relationship with Immediately Postoperative Parameters

OBJECTIVE

The aim of this study was to investigate the changes in spine-pelvis sagittal parameters from the standing position to the prone position and to study the relationship between sagittal parameters and immediately postoperative parameters.

METHODS

Thirty-six patients with old traumatic spinal fracture combined with kyphosis were enrolled. The preoperative standing position, prone position, and postoperative sagittal parameters of the spine and pelvis, including the local kyphosis Cobb angle (LKCA), thoracic kyphosis angle (TKA), lumbar lordosis angle (LLA), sacral slope (SS), pelvic tilt (PT), pelvic incidence minus lumbar lordosis angle (PI-LLA), and sagittal vertebral axis (SVA), were measured. The data of kyphotic flexibility and correction rate werecollected and analyzed. The parameters of the preoperative standing position, prone position and postoperative sagittal position were analyzed statistically. Correlation analysis and regression analysis of the preoperative standing and prone sagittal parameters and postoperative parameters were conducted.

RESULTS

There were significant differences in the preoperative standing position, prone position, and postoperative LKCA and TK. Correlation analysis showed that preoperative sagittal parameters of the standing position and prone position were all correlated with postoperative homogeneity. Flexibility was not related to the correction rate. Regression analysis showed preoperative standing, prone LKCA, and TK were linear with postoperative standing.

CONCLUSIONS

The LKCA and TK of old traumatic kyphosis obviously changed from the standing position to the prone position, which were linear with postoperative LKCA and TK and can be used to predict postoperative sagittal parameters. This change should be taken into account in the surgical strategy.

[Preoperative standing to prone spinal-pelvic sagittal parameter changes in old traumatic spinal fractures with kyphosis]

Objective

To investigate the changes in spinal-pelvic sagittal parameters from preoperative standing to prone position in old traumatic spinal fractures with kyphosis.

Methods

The clinical data of 36 patients admitted between December 2016 and June 2021 for surgical treatment of old traumatic spinal fractures with kyphosis, including 7 males and 29 females, aged from 50 to 79 years (mean, 63.9 years), were retrospectively analyzed. Lesion segments included 2 cases of T 11, 12 cases of T 12, 2 cases of T 11, 12, 4 cases of T 12 and L 1, 12 cases of L 1, 2 cases of L 2, 1 case of L 2, 3, and 1 case of L 3. The disease duration ranged from 4 to 120 months, with an average of 19.6 months. Surgical procedures included Smith-Petersen osteotomy in 4 cases, Ponte osteotomy in 6 cases, pedicle subtraction osteotomy in 2 cases, and improved fourth level osteotomy in 18 cases; the remaining 6 cases were not osteotomized. The bone mineral density ranged from -3.0 to 0.5 T, with a mean of -1.62 T. The spinal-pelvic sagittal parameters from preoperative standing to prone positions were measured, including local kyphosis Cobb angle (LKCA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and PI and LL mismatch (PI-LL). The kyphotic flexibility=(preoperative standing LKCA-preoperative prone LKCA)/preoperative standing LKCA×100%. Spinal-pelvic sagittal parameters were compared between standing position and prone position before operation, and Pearson correlation was used to judge the correlation between the parameters of standing position and prone position before operation.

Results

When the position changed from standing to prone, LKCA and TK decreased significantly ( P<0.05), while SS, LL, PT, and PI-LL had no significant difference ( P>0.05). Pearson correlation analysis showed that LL was significantly correlated with SS and PI-LL in both standing and prone positions ( P<0.05), and the correlation strength between LL and SS in prone position was higher than that in standing position. In the standing position, LKCA was significantly correlated with SS and PT ( P<0.05). However, when the position changed from standing to prone, the correlation between LKCA and SS and PT disappeared, while PT and PI-LL was positive correlation ( P<0.05). The kyphotic flexibility was 25.13%-78.79%, with an average of 33.85%.

Conclusion

For the patients of old traumatic spinal fractures with kyphosis, the preoperative LKCA and TK decrease significantly from standing position to prone position, and the correlation between spinal and pelvic parameters also changed, which should be taken into account in the formulation of preoperative surgical plan.

Is vertebral stenting kyphoplasty a good choice in the treatment of osteoporotic vertebral fracture? A series of 47 patients (v2)

Background

The incidence of vertebral fragility fracture is increasing over last three decades with an essential impact on quality of life. Some devices were proposed to improve conventional kyphoplasty in the last five years, known as vertebral stenting kyphoplasty (VSK).

Materials and Methods

All osteoporotic vertebral fractures (OVF) treated with VSK, single-level fracture without neurological impairment, and with more than 24 months of follow-up were included in the study. We recorded fracture types according to DGOU classification, fracture level, regional kyphosis angle (RKA), Oswestry disability index (ODI), and complications.

Results

Forty-seven consecutive patients were included. RKA significantly improved from pre to postoperative values (p<0.000001) and to follow-up values (p<0.00001). A significant difference was found between preoperative RKA of (OF2+OF3) and OF4 (p<0.00001), confirmed immediately after surgery (p= 0.005425) and at last follow up (p= 0.000947). A significant difference was found in correction of RKA between (OF2+OF3) and OF4 at injury time and after treatment (p<0.00001), and it was confirmed at the last follow-up (p=0.000026). ODI showed a significant difference between (OF2+OF3) and OF4 type of fractures (p=0.038216). We recorded five complications: 2 cases of leakage without neurological impairment, two progressions of kyphosis, and one implant migration.

Conclusions

VSK is an excellent and reliable option in the treatment of OVF, with good clinical results and preservation of obtained RKA at the time of treatment. However, in case of vertebral collapse with the involvement of both vertebral plates, surgeons must be aware of possible implant failure or migration.

Level of Evidence

4.

Predictors of adverse events after percutaneous pedicle screws fixation in patients with single-segment thoracolumbar burst fractures

BACKGROUND

Percutaneous pedicle screw fixation (PPSF) is the primary approach for single-segment thoracolumbar burst fractures (TLBF). The healing angle at the thoracolumbar junction is one of the most significant criteria for evaluating the efficacy of PPSF. Therefore, the purpose of this study was to analyze the predictors associated with the poor postoperative alignment of the thoracolumbar region from routine variables using a support vector machine (SVM) model.

METHODS

We retrospectively analyzed patients with TLBF operated at our academic institute between March 1, 2014 and December 31, 2019. Stepwise logistic regression analysis was performed to assess potential statistical differences between all clinical and radiological variables and the adverse events. Based on multivariate logistic results, a series of independent risk factors were fed into the SVM model. Meanwhile, the feature importance of radiologic outcome for each parameter was explored. The predictive performance of the SVM classifier was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy (ACC) and confusion matrices with 10-fold cross-validation, respectively.

RESULTS

In the recruited 150 TLBFs, unfavorable radiological outcomes were observed in 53 patients (35.33%). The relationship between osteoporosis (p = 0.036), preoperative Cobb angle (p = 0.001), immediate postoperative Cobb angle (p = 0.029), surgically corrected Cobb angle (p = 0.001), intervertebral disc injury (Score 2 p = 0.001, Score 3 p = 0.001), interpedicular distance (IPD) (p = 0.001), vertebral body compression rate (VBCR) (p = 0.010) and adverse events was confirmed by univariate regression. Thereafter, independent risk factors including preoperative Cobb angle, the disc status and IPD and independent protective factors surgical correction angle were identified by multivariable logistic regression. The established SVM classifier demonstrated favorable predictive performance with the best AUC = 0.93, average AUC = 0.88, and average ACC = 0.87. The variables associated with radiological outcomes, in order of correlation strength, were intervertebral disc injury (42%), surgically corrected Cobb angle (25%), preoperative Cobb angle (18%), and IPD (15%). The confusion matrix reveals the classification results of the discriminant analysis.

CONCLUSIONS

Critical radiographic indicators and surgical purposes were confirmed to be associated with an unfavorable radiographic outcome of TLBF. This SVM model demonstrated good predictive ability for endpoints in terms of adverse events in patients after PPSF surgery.