Biomechanical analysis of four- versus six-screw constructs for short-segment pedicle screw and rod instrumentation of unstable thoracolumbar fractures

The Comparison between Spinal Facet Joint Toothed Plate and Traditional Pedicle Screw-rod on Reduction of Thoracolumbar Fracture

OBJECTIVE

Thoracolumbar fractures are one of the most common fractures in clinical practice. Surgical intervention is recommended to restore spinal alignment or decompress the nerves when there are unstable fractures or neurological injuries. However, after excessive forward thrust force restoration, facet joint dislocation often occurs between the upper vertebra and the fractured vertebra, which usually leads to unsatisfactory reduction outcomes. Herein, we propose a novel spinal facet joint toothed plate to assist in fracture reduction. The purpose of this study is to evaluate the effectiveness of the new spinal facet joint toothed plate in preventing facet joint dislocation, and its advantages compared to traditional pedicle screw-rod decompression.

METHODS

A total of 26 patients in the toothed plate group and 93 patients in the traditional group who experienced thoracolumbar fracture with reduction were retrospectively included. Relevant patients' information and clinical parameters were collected. Furthermore, visual analogue scores (VAS) scores and Oswestry disability index (ODI) scores were also collected. Moreover, imaging parameters were calculated based on radiographs. Correlated data were analyzed by χ2 test and t test.

RESULTS

All patients in this study had no postoperative complications. Postoperative VAS scores and ODI scores (p < 0.001) were statistically significant (p < 0.001) in both groups compared with preoperative scores and further decreased (p < 0.001) at final follow-up. In addition, the postoperative vertebral margin ratio (VMR) (p < 0.001) and vertebral angle of the injured vertebrae (p < 0.001) were significantly improved compared with the preoperative period. There were no significant differences in postoperative VAS scores and ODI scores between the two groups. However, toothed plate reduction significantly improved the VMR (p < 0.05) and vertebral angle (p < 0.05) compared with conventional reduction. Ultimately, the total screw accuracy was 98.72% (sum of levels 0 and I), with 100% screw accuracy in the segment related to the tooth plate in the tooth plate group. The dislocation rate was higher in the conventional group (6.45%) than in the new serrated plate repositioning group (0.00%).

CONCLUSION

The facet toothed plate assisted reduction method prevents facet joint dislocation and improves fracture reduction compared to traditional reduction technique, hence it could be considered as a novel surgical strategy for thoracolumbar fracture reduction.

Should the level of the posterior instrumentation combined with the intermediate screw be a short segment or a long segment in thoracolumbar fractures with fusion to the fractured segment?

PURPOSE

It was aimed to compare the results of long segment posterior instrumentation with intermediate pedicular screw + fusion at the level of the fractured segment including one vertebra above and one below the fractured vertebra (LSPI) and short segment posterior instrumentation with intermediate pedicular screw + fusion at the level of the fractured segment including one vertebra above and one below the fractured vertebra (SSPI) in the surgical treatment of thoracolumbar vertebral fractures.

METHODS

Ninety patients with thoracolumbar vertebral (T11-L2) fractures operated between March 2015 and February 2022 were included in this retrospective study. The patients were divided into two groups as those who underwent LSPI (n, 54; age, 40.3) and those who underwent SSPI (n, 36; age, 39.7). Radiological evaluations like vertebral compression angle (VCA), vertebral corpus heights (VCH), intraoperative parameters, and complications were compared between the groups.

RESULTS

Correction in early postoperative VCA was statistically significantly better in LSPI (p = 0.003). At 1-year follow-up, postoperative VCA correction was significantly more successful in LSPI (p = 0.001). There was no difference between the two groups in terms of correction loss in VCA measured at 1-year follow-up. There was no statistically significant difference between the two groups in terms of postoperative VCH, VCH at 1-year follow-up, and correction loss in VCH.

CONCLUSION

LSPI provides better postoperative kyphosis correction of the fractured vertebra than SSPI. Regarding the segment level of posterior instrumentation, there was no difference between the two groups in terms of the loss of achieved correction of VCA, ABH, and PBH at 1-year follow-up. Operating a thoracolumbar fracture with LSPI will lengthen the operation and increase the number of intraoperative fluoroscopies compared to SSPI.

Percutaneous monoplanar screws versus hybrid fixed axial and polyaxial screws in intermediate screw fixation for traumatic thoracolumbar burst fractures: a case-control study

BACKGROUND

To compare the clinical and radiological outcomes of monoplanar screws (MSs) versus hybrid fixed axial and polyaxial screws (HSs) in percutaneous short-segment intermediate screw fixation (PSISF) for traumatic thoracolumbar burst fractures (TTBFs) in patients without neurologic impairment.

METHODS

A consecutive series of 100 patients with single-segment TTBFs and no neurologic impairment who underwent PSISF with 6 monoplanar screws (MS group) or correct were retrospectively enrolled. The demographic data, radiologic evaluation indicators, perioperative indicators and clinical assessment indicators were analysed between the MS group and HS group.

RESULTS

The demographic data and perioperative indicators were not significantly different in the two groups (P > 0.05). The postoperative anterior vertebral height ratio (AVHR), kyphosis Cobb angle (KCA), vertebral wedge angle (VWA) and spinal canal encroachment rate (SCER) were significantly improved in both groups (*P < 0.05). The MS group obtained better correction than the HS group in terms of improvement in the AVHR, KCA and VWA after surgery (*P < 0.05). At the last follow-up, the MS group had less correction loss of AVHR, KCA and VWA (*P < 0.05). The MS group presented greater improvement in the SCER at the last follow-up (*P < 0.05). The visual analogue scale (VAS) score and Oswestry Disability Index (ODI) score of all patients were significantly better postoperatively than those preoperatively (*P < 0.05), and the scores collected at each follow-up visit did not differ significantly between the two groups (P > 0.05). In the MS group, no internal fixation failure was observed during the follow-up period, but, in the HS group, two cases of internal fixation failure were observed at the last follow-up (one case of rod loosening and one case of screw breakage).

CONCLUSIONS

Both MSs and HSs fixation are effective treatments for TTBFs and have comparable clinical outcomes. In contrast, MSs fixation can improve the correction effect, better improve the SCER, and further reduce correction loss as well as reduce the incidence of instrumentation failure. Therefore, MSs fixation might be a better option for treating TTBFs in patients without neurological deficits.

Analysis of factors influencing the intravertebral shell phenomenon after posterior reduction internal fixation of thoracolumbar fracture: a retrospective study

STUDY DESIGN

A retrospective study.

PURPOSE

The study objectives were as follows: 1) to analyze the factors influencing the occurrence of the intravertebral shell phenomenon (ISP) after thoracolumbar spinal fracture surgery and the evolutionary outcome of this phenomenon; and 2) to make recommendations for the clinical prevention and treatment of ISP.

METHODS

We retrospectively analyzed 331 patients with single-segment fractures of the thoracolumbar spine treated with internal fixation via a pedicle screw-rod system. Univariate and multivariate logistic regression were used to analyze factors influencing ISP.

RESULTS

A total of 260 patients (78.5%) developed ISP after surgery. Reduced bone mineral density, screw insertion depth, degree of vertebral body injury, and excessive vertebral body spreading were significantly associated with the occurrence of ISP (P < 0.05). A total of 166 of the 260 patients were reviewed via CT at 1 year postoperatively. Among them, 104 patients (62.6%) showed shrinkage or healed vertebral cavities, and 62 patients (37.4%) showed enlarged vertebral cavities or collapsed endplates.

CONCLUSION

In clinical management, surgeons need to focus on risk factors for ISP, which include decreased bone density, preoperative vertebral overcompression, intraoperative vertebral overextension, screw insertion depth, and the degree of vertebral repositioning. At the 1-year postoperative follow-up, some of the vertebrae with ISP failed to heal or even showed vertebral cleft enlargement, which would affect the stability of the internal fracture fixation device and the quality of the patient's daily life.

Comparative finite element analysis of posterior short segment fixation constructs with or without intermediate screws in the fractured vertebrae for the treatment of type a thoracolumbar fracture

Six-screw short-segment posterior fixation for thoracolumbar fractures, which involves intermediate screws at the fractured vertebrae has been proposed to reduce the rates of kyphosis recurrence and implant failure. Yet, little is known about the mechanisms and biomechanical responses by which intermediate screws at the fracture vertebrae enhance fixation strength. The objective of this study was to investigate the biomechanical properties that are associated with the augmentation of intermediate screws in relation to the severity of type A thoracolumbar fracture using finite element analysis. Short-segment stabilization models with or without augmentation screws at fractured vertebrae were established based on finite element model of moderate compressive fractures, severe compressive fractures and burst fractures. The spinal stiffness, stresses at the implanted hardware, and axial displacement of the bony defect were measured and compared under mechanical loading conditions. All six-screw stabilization showed a decreased range of motion in extension, lateral bending, and axial rotation compared to the traditional four-screw fixation models. Burst thoracolumbar fracture benefited more from augmentation of intermediate screws at the fracture vertebrae. The stress of the rod in six-screw models increased while decreased that of pedicle screws. Our results suggested that patients with more unstable fractures might achieve greater benefits from augmentation of intermediate screws at the fracture vertebrae. Augmentation of intermediate screws at the fracture vertebrae is recommended for patients with higher wedge-shaped or burst fractures to reduce the risk of hardware failure and postoperative re-collapse of injured vertebrae.

Short-segment fixation and transpedicular bone grafting for the treatment of thoracolumbar spine fracture

Purpose

Thoracolumbar fracture is one of the most common fractures of spine. And short-segment posterior fixation including the fractured vertebra (SSPFI) is usually used for the surgical treatment of it. However, the outcomes of SSPFI for different types of thoracolumbar fractures are not clear, and whether it is necessary to perform transpedicular bone grafting is still controversial. This study was conducted to determine the clinical efficacy of SSPFI for the treatment of different types of single-level thoracolumbar fracture, and make clear what kind of fractures need transpedicular bone grafting during the surgery.

Methods

Patients with single-level thoracolumbar fracture undergoing SSPFI surgery between January 2013 and June 2020 were included in this study. The operative duration, intraoperative blood loss, anterior vertebral height ratio (AVHR) and anterior vertebral height compressive ratio (AVHC) of the fractured vertebra, local kyphotic Cobb angle (LKA), vertebral wedge angle (VWA) and correction loss during follow up period were recorded. Outcomes between unilateral and bilateral pedicle screw fixation for fractured vertebra, between SSPFI with and without transpedicular bone grafting (TBG), and among different compressive degrees of fractured vertebrae were compared, respectively.

Results

A total of 161 patients were included in this study. All the patients were followed up, and the mean follow-upped duration was 25.2 ± 3.1 months (6-52 months). At the final follow-up, the AVHR was greater, and the LKA and VWA were smaller in patients with bilateral fixation (6-screw fixation) than those with unilateral fixation (5-screw fixation) of AO type A3/A4 fractures (P < 0.001). The correction loss of AVHR, LKA and VWA in fractured vertebra were significantly great when preoperative AVHC was >50% (P < 0.05). For patients with AVHC >50%, the correction loss in patients with TBG were less than those without TBG at the final follow-up (P < 0.05).

Conclusions

SSPFI using bilateral fixation was more effective than unilateral fixation in maintaining the fractured vertebral height for AO type A3/A4 fractures. For patients with AVHC >50%, the loss of correction was more obvious and it can be decreased by transpedicular bone grafting.

Percutaneous pedicle screw fixation without arthrodesis of 368 thoracolumbar fractures: long-term clinical and radiological outcomes in a single institution

PURPOSE

Traumatic thoracolumbar (TL) fractures are the most common vertebral fractures. Although a consensus on the preferred treatment is missing, percutaneous pedicle screw fixation (PPSF) has been progressively accepted as treatment option, since it is related to lower soft tissues surgical-injury and perioperative complications rate. This study aims to evaluate the long-term clinical-radiological outcomes after PPSF for TL fractures at a single tertiary academic hospital.

METHODS

This is a retrospective cohort study. Back pain was obtained at preoperative, postoperative and final follow-up using Visual Analog Scale. Patient-reported outcomes, the Oswestry Disability Index and the 36-Item Short Form, were obtained to asses disability during follow-up. Radiological measures included Cobb angle, mid-sagittal index, sagittal index (SI) and vertebral body height loss. A multivariate regression analysis on preoperative radiological features was performed to investigate independent risk factors for implant failure.

RESULTS

A total of 296 patients with 368 TL fractures met inclusion criteria. Mean follow-up was 124.3 months. The clinical and radiological parameters significantly improved from preoperative to last follow-up measurements. The multivariate analysis showed that Cobb angle (OR = 1.3, p < 0.001), SI (OR = 1.5, p < 0.001) and number of fractures (OR = 1.1, p = 0.05), were independent risk factors for implant failure. The overall complication rate was 5.1%, while the reoperation rate for implant failure was 3.4%.

CONCLUSIONS

In our case series, PPSF for TL injuries demonstrated good long-term clinical-radiological outcomes, along with low complication and reoperation rates. Accordingly, PPSF could be considered as a valuable treatment option for neurologically intact patients with TL fractures. Additionally, in this cohort, number of fractures ≥ 2, Cobb angle ≥ 15° and sagittal index ≥ 21° were independent risk factors for implant failure.

Effect of the intermediate pedicle screws and their insertion depth on sagittal balance and functional outcomes of lumbar fracture

OBJECTIVE

This study aimed to examine the effect of the intermediate pedicle screws and their insertion depth on sagittal balance and functional outcomes of lumbar fracture.

METHODS

This study reviewed 1,123 patients with lumbar fractures between January 2015 and June 2019, and 97 patients were ultimately enrolled in this study: Group A: 32 patients in the four-pedicle screws fixation group; Group B: 28 patients in the six-pedicle screws fixation with long intermediate pedicle screws group; Group C: 37 patients in the six-pedicle screws fixation with short intermediate pedicle screws group. The radiographic outcomes were assessed with lumbar lordosis (LL), segmental lordosis (SL), fractured vertebral lordosis (FL), sacral slope (SS), pelvic incidence (PI), and pelvic tilt (PT). The visual analog scale (VAS) and the Oswestry disability index (ODI) scores were used for assessing functional outcomes.

RESULTS

The PI, PT, and SS showed no significant differences between the three groups (P > 0.05). Compared with Group A, Groups B and C showed better FL, SL, and LL 1 month after operation (5.96 ± 1.67/4.81 ± 1.49 vs. 8.78 ± 2.90, 24.39 ± 3.80/23.70 ± 4.10 vs. 20.09 ± 3.33, 39.07 ± 3.61/39.51 ± 3.23 vs. 36.41 ± 3.11, P < 0.05) and at final follow-up (8.75 ± 1.40/6.78 ± 1.70 vs. 11.31 ± 2.61, 22.11 ± 3.39/23.70 ± 4.10 vs. 17.66 ± 2.60, 38.04 ± 3.49/39.51 ± 3.23 vs. 35.41 ± 3.11, P < 0.05). The FL of Group C were significantly better than those of Group B 1 month after operation (4.81 ± 1.49 vs. 5.96 ± 1.67, P < 0.05) and at final follow-up (6.78 ± 1.70 vs. 8.75 ± 1.40, P < 0.05). No significant differences in VAS and ODI were found between Group A and Group B (P > 0.05). There were also no significant differences in VAS and ODI between Group A and Group C (P > 0.05). However, The VAS and ODI of Group C showed better than Group B 1 month after operation (3.05 ± 0.70 vs. 3.54 ± 0.79, 17.65 ± 3.41 vs. 19.71 ± 2.35, P < 0.05) and at final follow-up (2.19 ± 0.46 vs. 2.57 ± 0.57, 13.81 ± 2.20 vs. 15.57 ± 1.73, P < 0.05).

CONCLUSIONS

Both four-pedicle screw fixation and six-pedicle screw fixation were effective in treating lumbar fracture. However, six-pedicle screw fixation with short intermediate pedicle screws showed better radiographic and functional outcomes after surgery. Therefore, we recommend six-pedicle screws fixation with short intermediate pedicle screws for the long-term recovery of sagittal balance and function.

Minimally invasive pedicle screw fixation, including the fractured vertebra, combined with percutaneous vertebroplasty for treatment of acute thoracolumbar osteoporotic compression fracture in middle-age and elderly individuals: A prospective clinical study

To evaluate the feasibility, efficacy, and safety of minimally invasive pedicle screw (MIPS) fixation, including the fractured vertebra, combined with percutaneous vertebroplasty (PVP) for the treatment of acute thoracolumbar osteoporotic compression fracture in middle-age and elderly individuals.Between January 2016 and August 2019, a total of 30 patients, with a mean age of 69.4 years (range, 58-75 years), who experienced thoracic or lumbar fracture without neurological deficits, underwent the MIPS procedure combined with PVP. Preoperative and postoperative pain were assessed using a visual analog scale and Oswestry Disability Index. Cobb angles and anterior column height were measured on lateral radiographs before surgery and at 3 days, 1, 3, and 6 months, and 1 and 2 years at final follow-up after surgery.All patients underwent surgery successfully, with a mean follow-up of 18.2 ± 5.7 months (range, 12-45 months). Mean preoperative visual analog scale score decreased from 7.3 ± 2.2 to 1.4 ± 0.3 at the final follow-up (P < .05). Mean preoperative Oswestry Disability Index decreased from 84.2 ± 10.3 to 18.8 ± 7.5 (P < .05) at the final follow-up. The Kyphosis angle of operative segment was improved from preoperative (21.38 ± 1.68)° to (4.01 ± 1.38)° 3 days postoperatively and (5.02 ± 1.09)° at final follow-up (P < .05). The anterior vertebral height was improved from preoperative (49.86 ± 6.50)% to (94.01 ± 1.79)% 3 days postoperatively and (91.80 ± 1.88)% at final follow-up (P < .05). No significant changes in vertebral body height restoration were observed during 2 years of follow-up after surgery. In addition, there were no instrumentation failures or complications in any of the patients.MIPS, including the fractured vertebra, combined with PVP, was a reliable and safe procedure, with satisfactory clinical and radiological results for the treatment of thoracolumbar osteoporotic compression fracture in patients without neurological deficits.

Comparison of monoplanar and polyaxial screw fixation systems in percutaneous intermediate fixation for thoracolumbar fractures

Background

The newly developed monoplanar pedicle screws (MPPSs) can mobile in axial plane but fixed in the sagittal plane, which holds potential to combine ease of rod placement with sagittal plane strength theoretically. So far, few clinical studies focused on the outcomes of MPPSs for treatment of thoracolumbar fractures (TLFs). The aim of this study was to compare the efficacy of MPPSs to polyaxial pedicle screws (PAPSs) in percutaneous intermediate fixation of TLFs.

Methods

Seventy-eight patients who sustained TLFs without neurological deficits and underwent percutaneous intermediate fixation using MPPSs (40 patients) or PAPSs (38 patients) with a minimum 1-year follow-up were included in this study. The operation time, blood loss, local Cobb angle (LCA), vertebral wedge angle (VWA), anterior body height ratio (ABHR), visual analogue scale (VAS) and Oswestry Disability Index (ODI) were collected.

Results

No significant differences were observed in baseline demographics, clinical characteristics, operation time or blood loss between the two groups (P > 0.05). The postoperative LCA, VWA and ABHR were significantly corrected compared to these parameters preoperatively in both groups (^#P < 0.05). The postoperative LCA, VWA and ABHR in the MPPS group were significantly better corrected than those in the PAPS group (*P < 0.05). Furthermore, the correction loss of LCA, VWA and ABHR in the MPPS group was significantly lower than that in the PAPS group (*P < 0.05). However, no significant difference in VAS and ODI scores was observed between the two groups.

Conclusions

MPPSs showed similar efficiency as PAPSs in percutaneous intermediate fixation surgical procedures. More importantly, MPPSs achieved better radiological performance than PAPSs in the correction of TLFs and the prevention of correction loss.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05129-8.

A retrospective comparative study of clinical efficacy of percutaneous short segment pedicle screw fixation with or without screwing of the fractured vertebra with O-arm navigation

Objective

To retrospectively analyze the short and long-term efficacies of O-arm-navigated percutaneous short segment pedicle screw fixation, with or without screwing of the fractured vertebra.

Methods

A total of 42 patients who underwent O-arm-navigated percutaneous short segment pedicle screw fixation for the treatment of thoracolumbar fractures from February 2015 to December 2018 were selected for analysis. The patients were divided into two groups according to the surgical intervention they received: Group A received percutaneous short segment pedicle screw fixation with screwing of the fractured vertebra and Group B received percutaneous short segment pedicle screw fixation without screwing of the fractured vertebra. Radiographic analysis included Cobb angles and percentage of anterior vertebral height (AVH%). Clinical functional outcomes were assessed using the visual analog scale (VAS) for back pain and the oswestry disability index (ODI) scores.

Results

No significant differences were observed in the operation time and intraoperative blood loss between the two groups (P > 0.05). The length of incision was statistically significantly different between the two groups (P < 0.05). There was no significant difference in Cobb angle and AVH% between the two groups before and after the surgery (P > 0.05). However, the Cobb angle and AVH% were both significantly larger in Group A than Group B at the final follow-up (P < 0.05). In terms of clinical outcomes, there were no statistically significant differences in VAS and ODI scores between the two groups (P > 0.05).

Conclusion

In the short term, both minimally invasive treatments were safe and effective in treating thoracolumbar fracture. Although there was significant difference between the two groups in Cobb angle and vertebral body height at the last follow-up, the difference was small. Therefore, these specific parameters will be an important outcome measure in further investigations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05069-3.

Kyphosis After Thoracolumbar Spine Fractures: WFNS Spine Committee Recommendations

Thoracolumbar fractures change the biomechanics of the spine. Load distribution causes kyphosis by the time. Treatment of posttraumatic kyphosis is still controversial. We reviewed the literature between 2010 and 2020 using a search with keywords “thoracolumbar fracture and kyphosis.” We removed osteoporotic fractures, ankylosing spondylitis fractures, non-English language papers, case reports, and low-quality case series. Up-to-date information on posttraumatic kyphosis management was reviewed to reach an agreement in a consensus meeting of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. The first meeting was conducted in Peshawar in December 2019 with WFNS Spine Committee members’ presence and participation. The second meeting was a virtual meeting via the internet on June 12, 2020. We utilized the Delphi method to administer the questionnaire to preserve a high degree of validity. We summarized 42 papers on posttraumatic kyphosis. Surgical treatment of thoracolumbar kyphosis due to unstable burst fractures can be done via a posterior only approach. Less blood loss and reduced surgery time are the main advantages of posterior surgery. Kyphosis angle for surgical decision and fusion levels are controversial. However, global sagittal balance should be taken into consideration for the segment that has to be included. Adding an intermediate screw at the fractured level strengthens the construct.

A comparison of monoaxial pedicle screw versus polyaxial pedicle screw in short-segment posterior fixation for the treatment of thoracolumbar fractured vertebra

Background

Posterior pedicle screw fixation had been applied to maintain spinal stability and avoid further nerve damage in thoracolumbar fracture. This study aimed to evaluate the efficacy of short-segment posterior fixation with monoaxial pedicle screws versus polyaxial pedicle screws in treating thoracolumbar fracture.

Methods

A total of 75 patients with thoracolumbar fracture who underwent short-segment posterior fixation with monoaxial pedicle screw (group A) or polyaxial pedicle screw (group B) were retrospectively enrolled. The patient demographic and radiological data were analyzed between the two groups.

Results

A total of 63 patients with an average age of 44.7±11.5 years were finally recruited in this study. There were no significant differences in age, gender, fracture level, thoracolumbar injury classification and severity scale (TLISS) score, American Spinal Injury Association (ASIA) score, Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification, and hospital stay between the two groups (P>0.05). At the last follow-up, the prevertebral height ratio and normal-to-injured vertebral height ratio were significantly decreased in group A compared to group B (P=0.027 and P=0.007, respectively).

Conclusions

Short-segment posterior fixation with monoaxial or polyaxial pedicle screw for fractured thoracolumbar vertebra can restore injured vertebral height. Compared with polyaxial pedicle screw, monoaxial pedicle screw endows stronger leverage which is more beneficial for restoring injured vertebral height and recovery of the damaged endplate in thoracolumbar short-segment posterior fixation.

Surgical Treatment of Multiple Osteoporotic Fractures of the Dorsolumbar Spine: Case Report

Osteoporotic vertebral fractures are a common type of fracture and affect a significant number of subjects with osteoporosis. Despite the high fracture risk, the concomitant occurrence of vertebral fractures at non-contiguous levels is very rare. We report the case of a patient with three burst dorsolumbar spine fractures at non-contiguous levels who was treated with percutaneous kyphoplasty and transpedicular posterior fixation. Six months after the surgery, the patient walks autonomously and without pain; in addition, there is no radiological evidence of fracture reduction loss.

Long-Term Reliability of the Two-Segment Fusion Technique in the Treatment of Thoracolumbar Fractures Using Screws in the Fractured Vertebra

BACKGROUND

There is some controversy about which is the best approach, decompression technique and number of fixed levels in the surgical treatment for burst thoracolumbar fractures. Without a neurological injury, correcting thoracolumbar kyphosis and preventing mechanical failure should be the main concerns. The two-segment short fusion with screws at fractured vertebra by posterior approach was performed in 64 patients. Although a significant increase of postoperative kyphosis was observed, there were not clinical consequences, nor was there reintervention for mechanical failure.

METHODS

Patients with unstable T11-L2 burst fractures and a two-level fusion including screws at the injured vertebra between 2000 and 2015 were included in the study. Demographic, clinical, and radiological variables were analyzed. Thoracolumbar, segmental, and vertebral kyphosis and anterior and posterior vertebral height were measured preoperatively, postoperatively, at one-year, and at the end of follow-up in the radiological study. The statistical analysis consisted of a descriptive analysis, and we used the t test to compare the preoperative, postoperative, one-year, and end-of-follow-up radiographs to observe a thoracolumbar T10-L2 kyphosis increase. Significance level was established at P < .05.

RESULTS

Fifty-four patients were included. A statistically significant increase of vertebral, segmental, and thoracolumbar kyphosis (P < .05) was observed during follow-up, without clinical consequences.

CONCLUSIONS

Two-segment fusion is an effective technique and allows initial deformity kyphotic correction after thoracolumbar burst fracture. The thoracolumbar kyphosis increased during the follow-up, without pain, disability, or mechanical failure.

LEVEL OF EVIDENCE

2a.

Clinical efficacy and outcome of intelligently inflatable reduction in conjunction with percutaneous pedicle screw fixation for treating thoracolumbar burst fractures

Objective

This study was performed to describe a new minimally invasive surgical technique and to explore its effects and practical use in the clinical setting.

Methods

In total, 22 patients with single-segment thoracolumbar burst fractures underwent treatment with an intelligently inflatable reduction device before common percutaneous pedicle screw fixation. Complications were recorded and short-term effectiveness was evaluated using the visual analogue scale (VAS) score for pain, Oswestry Disability Index (ODI), kyphotic Cobb angle, and anterior edge height of the fractured vertebra preoperatively and postoperatively.

Results

The patients were followed up from 2 to 5 years. The differences in the VAS score and ODI reached statistical significance at different time points. Similar significant differences were observed in the kyphotic Cobb angle and the vertebral body anterior height except between the two postoperative measurements.

Conclusions

The current study indicated that use of the intelligently inflatable reduction device with conventional percutaneous pedicle screw fixation can improve the reduction and healing of single-segment thoracolumbar burst fractures in adult patients. This technique induces minimal trauma, provides reliable fixation, and has few complications.

A Hybrid Uniplanar Pedicle Screw System with a New Intermediate Screw for Minimally Invasive Spinal Fixation: A Finite Element Analysis

Purpose

A hybrid pedicle screw system for minimally invasive spinal fixation was developed based on the uniplanar pedicle screw construct and a new intermediate screw. Its biomechanical performance was evaluated using finite element (FE) analysis.

Methods

A T12-L2 FE model was established to simulate the L1 vertebral compression fracture with Magerl classification A1.2. Six fixation models were developed to simulate the posterior pedicle screw fracture fixation, which were divided into two subgroups with different construct configurations: (1) six-monoaxial/uniplanar/polyaxial pedicle screw constructs and (2) four-monoaxial/uniplanar/polyaxial pedicle screw constructs with the new intermediate screw. After model validation, flexion, extension, lateral bending, and axial rotation with 7.5 Nm moments and preloading of 500 N vertical compression were applied to the FE models to compare the biomechanical performances of the six fixation models with maximum von Mises stress, range of motion, and maximum displacement of the vertebra.

Results

Under four loading scenarios, the maximum von Mises stresses were found to be at the roots of the upper or lower pedicle screws. In the cases of flexion, lateral bending, and axial rotation, the maximum von Mises stress of the uniplanar screw construct lay in between the monoaxial and polyaxial screw constructs in each subgroup. Considering lateral bending, the uniplanar screw construct enabled to lower the maximum von Mises stress than monoaxial and polyaxial pedicle screw constructs in each subgroup. Two subgroups showed comparable results of the maximum von Mises stress on the endplates, range of motion of T12-L1, and maximum displacement of T12 between the corresponding constructs with the new intermediate screw or not.

Conclusions

The observations shown in this study verified that the hybrid uniplanar pedicle screw system exhibited comparable biomechanical performance as compared with other posterior short-segment constructs. The potential advantage of this new fixation system may provide researchers and clinical practitioners an alternative for minimally invasive spinal fixation with vertebral augmentation.

Posterior short segment fixation including the fractured vertebra combined with kyphoplasty for unstable thoracolumbar osteoporotic burst fracture

BACKGROUND

Various studies have described the efficacy and safety of the treatment for unstable thoracolumbar osteoporotic burst fracture, however, there is still no consensus on the optimal treatment regimen. The aim of this study was to evaluate the clinical and radiographic results of posterior short segment fixation including the fractured vertebra (PSFFV) combined with kyphoplasty (KP) for unstable thoracolumbar osteoporotic burst fracture.

METHODS

Forty-three patients with unstable thoracolumbar osteoporotic burst fracture underwent PSFFV combined with KP from January 2015 to December 2017 were analyzed retrospectively. Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) was used to evaluate the clinical outcome, radiological parametres including local kyphotic Cobb angle, percentage of the anterior, middle and posterior height of the fractured vertebra were measured and compared pre-operation, post-operation and at final follow-up.

RESULTS

All patients underwent surgery successfully and with an average follow-up of 19.2 ± 6.7 months (rang 15-32). The VAS decreased from 7.1 ± 2.3 pre-operation to 1.6 ± 0.4 at the final follow-up (p < 0.05). The ODI decreased from 83.1 ± 10.5 pre-operation to 19.2 ± 7.3 (P < 0.05) at the final follow-up. The correction of local kyphotic angle was 16.9° ± 5.3° (p < 0.05), and the loss of correction was 3.3° ± 2.6° (p > 0.05), the correction of anterior vertebral height was 30.8% ± 8.6% (p < 0.05), and the loss of correction was 4.5% ± 3.9% (p > 0.05), the correction of middle vertebral height was 26.4% ± 5.8% (p < 0.05), and the loss of correction was 2.0% ± 1.6% (p > 0.05), the correction of posterior vertebral height was 9.4% ± 6.9% (p < 0.05), and the loss of correction was 1.6% ± 1.3% (p > 0.05). Two cases of screw pullout and 8 cases of cement leakage were observed, but without clinical consequence.

CONCLUSIONS

PSFFV combined with KP is a reliable and safe procedure with satisfactory clinical and radiological results for the treatment of unstable thoracolumbar osteoporotic burst fracture.

Pedicle screw fixation of thoracolumbar fractures: conventional short segment versus short segment with intermediate screws at the fracture level-a systematic review and meta-analysis

OBJECTIVE

Posterior short-segment fixation (4-screw construct = 4S) is the conventional surgical technique for thoracolumbar fractures. The effect of adding two intermediate pedicle screws at the fractured level (6-screw construct = 6S) is still a matter of debate. This review aims to compare the results between 4 and 6S pedicle screw fixation for thoracolumbar fractures.

METHODS

A systematic review and meta-analysis were performed. The databases PubMed, Embase and Google Scholar were searched until January 2020. Inclusion criteria were studies comparing 4S and 6S techniques in patients with thoracolumbar fractures. Non-comparative studies and studies without full text were excluded. Cochrane risk of bias was assessed, and the GRADE approach was used to present the quality of evidence.

RESULTS

Twenty-seven studies, of which 21 randomized controlled trials, with a total of 1890 patients (940 with 4S and 950 with 6S) were included. Meta-analysis showed that the 6S technique resulted in significantly lower pain scores, better short-term and long-term Cobb angles, less loss of correction and less implant failures. However, longer operation time and more blood loss were seen with the 6S technique. Length of hospital stay, Oswestry Disability Index scores and infections did not differ significantly between the 6S and 4S techniques. Quality of the evidence according to GRADE was moderate to low.

CONCLUSION

In the treatment of thoracolumbar fractures, adding intermediate screws at the fracture level (6S) results in less post-operative pain, better radiological outcomes and less implant failure at the cost of a longer operation time and higher blood loss.

Effect of the short-segment internal fixation with intermediate inclined-angle polyaxial screw at the fractured vertebra on the treatment of Denis type B thoracolumbar fracture

BACKGROUND

Short-segment internal fixation with intermediate straight-forward monoaxial screws (SSIF-SFM) and long-segment internal fixation (LSIF) are the two major surgical options for thoracolumbar (TL) fracture. However, SSIF-SFM might not provide adequate support to the spine, and LSIF is unnecessarily extensive. SSIF with intermediate inclined-angle polyxial screw (SSIF-IAP) might offer an alternative solution for the treatment of TL fracture.

METHODS

A retrospective study was conducted. Sixty-nine patients (47 males and 22 females; average 34.5 years) with Denis type B TL fracture who met the criteria for inclusion were enrolled. Sagittal Cobb's angle (SCA), anterior vertebral body height (AVBH), vertebral body index (VBI), and spinal canal encroachment (SCE) were measured and assessed. Visual analogue scale (VAS) and Oswestry disability index (ODI) were also evaluated.

RESULTS

The average values of incision length, blood loss, duration of operation, and hospital stay in the SSIF-IAP group and SSIF-SFM group were significantly decreased compared with those in the LSIF group. The AVBH and VBI in the SSIF-IAP group and LSIF group were significantly improved than those in the SSIF-SFM group at 6-month and the latest follow-ups (P < 0.05). The correction losses of AVBH and VBI (calculated by the reduction of AVBH and VBI) in the SSIF-IAP group and LSIF group were also significantly decreased compared with those in the SSIF-SFM group at 6-month and the latest follow-ups (P < 0.05). There was no significant difference of SCE among the three groups postoperatively. The VAS and ODI in the SSIF-IAP group and SSIF-SFM group were significantly decreased compared with those in the LSIF group at 6-month and the latest follow-ups (P < 0.05).

CONCLUSION

Both SSIF-IAP and LSIF can improve the biomechanical stability as compared with SSIF-SFM. Moreover, SSIF-IAP was less extensive compared to LSIF. SSIF-IAP was an effective and reliable operative technique for patients with Denis type B TL fracture.

Effect of RTS versus percutaneous conventional pedicle screw fixation on type A thoracolumbar fractures: a retrospective cohort study

PURPOSE

This study aims at evaluating the effects of RTS (rotation softened trauma fixation system) compared with PCPSF (percutaneous conventional pedicle screw fixation) on type A thoracolumbar fractures.

METHODS

In this retrospective cohort study, 116 patients with type A thoracolumbar fractures from March 2014 to June 2018 were enrolled. PCPSF was performed in 60 patients, meanwhile the other 56 patients accepted RTS. VAS scores, Cobb angle, anterior vertebral height (AVH) and perioperative data were compared between the two groups.

RESULTS

Both groups were consistent with baseline on demographic and clinical characteristics. No significant difference was observed in VAS score between-group before and after operation. One year after surgery, the VAS score of RTS group was lower than that of PCPSF group (0.7 ± 0.3 vs. 1.5 ± 0.4). The postoperative AVH (%) in PCPSF was 82.3% (95%CI, 81.7-84.6), and 91.78% (95% CI, 91.1-92.4) in RTS. The postoperative improvement rate of AVH (%) in RTS was higher than that in PCPSF (30.6 ± 5.0 [95% CI, 29.2-32.0] vs. 22.0 ± 7.3 [95% CI, 20.2-24.2]). The postoperative Cobb angle (°) in PCPSF was 2.6 ± 3.4 (95%CI,11.7-13.5), and 7.5 ± 2.0 (95%CI,7.0-8.0) in RTS. The postoperative correction of Cobb angle (°) in RTS was higher than that in PCPSF (16.1 ± 3.8 95%CI,15.1-17.1] vs. 11.6 ± 5.2 95%CI,10.3-13.1]).

CONCLUSIONS

Compared with PCPSF, RTS has advantages in restoring the anterior vertebral height and reducing local kyphosis.

Short-Segment Instrumentation with Fractured Vertebrae Augmentation by Screws and Bone Substitute for Thoracolumbar Unstable Burst Fractures

Background

For thoracolumbar burst fractures, traditional four-screw (one above and one below) short-segment instrumentation is popular and has a high failure rate. Additional augmentation at the fractured vertebrae is believed to reduce surgical failure. The purpose of this study was to examine the clinical and radiographic results of patients who underwent short-segment posterior instrumentation with augmentation by screws and bone substitutes at the fractured vertebrae and to compare these data to those of patients who underwent long-segment instrumentation for thoracolumbar burst fractures.

Methods

The study group had twenty patients who underwent short-segment instrumentation with additional augmentation by two screws and bone substitutes at the fractured vertebrae. The control group contained twenty-two patients who underwent eight-screw long instrumentation without vertebra augmentation. Local kyphosis and the anterior body height of the fractured vertebrae were measured. The severity of the fractured vertebrae was evaluated with the load sharing classification (LSC). Any implant failure or loss of correction >10° at the final follow-up was defined as surgical failure.

Results

Both groups had similar distributions in terms of age, sex, the injured level, and the mechanism of injury before operation. During the operation, the study group had significantly less blood loss (136.0 vs. 363.6 ml, p=0.001) and required shorter operating times (146.8 vs. 157.5 minutes, p=0.112) than the control group. Immediately after surgery, the study group had better correction of the local kyphosis angle (13.4° vs. 11.9°, p=0.212) and restoration of the anterior height (34.7% vs. 31.0%, p=0.326) than the control group. At the final follow-up, no patients in the study group and only one patient in the control group experienced surgical failure.

Conclusions

Patients with thoracolumbar burst fractures who received six-screw short-segment posterior fixators with augmentation at the level of the fractured vertebrae via injectable artificial bone substitute achieved satisfactory clinical and radiographic results, and this method could replace long-segment instrumentation methods used in unstable thoracolumbar burst fractures.

Short-Segment Fixation of Thoracolumbar Fractures with Incorporated Screws at the Level of Fracture

Objective

To evaluate the effect of including the fractured vertebra in the short‐segment fixation of thoracolumbar (TL) fractures.

Methods

A total of 32 patients with thoraco‐lumbar fractures, selected between August 2013 and February 2016, were managed by short‐segment fixation with screws at the level of the fracture, and decompression was performed only for patients with neurological deficits. The patients' functional outcome was assessed using the visual analogue scale (VAS) score for pain and the American Spinal Injury Association (ASIA) score for neurological condition. All patients were followed up with radiographs.

Results

Patients with complete neurologic deficits (n = 3) did not show any neurologic recovery. All ASIA B patients improved to ASIA C. Five ASIA C patients improved to ASIA E. The remaining five ASIA C patients improved to ASIA D. All ASIA D patients improved to ASIA B. At the final follow‐up examination, the mean anterior vertebral height was 21 ± 5 mm, indicating no significant height loss during the follow‐up period.

Conclusion

Short‐segment fixation of TL fractures with inclusion of the fracture level into the construct offers good correction of segmental kyphosis, vertebral wedging, and vertebral height loss.

Finite Element Study to Evaluate the Biomechanical Performance of the Spine After Augmenting Percutaneous Pedicle Screw Fixation With Kyphoplasty in the Treatment of Burst Fractures

Percutaneous pedicle screw fixation (PPSF) is a well-known minimally invasive surgery (MIS) employed in the treatment of thoracolumbar burst fractures (TBF). However, hardware failure and loss of angular correction are common limitations caused by the poor support of the anterior column of the spine. Balloon kyphoplasty (KP) is another MIS that was successfully used in the treatment of compression fractures by augmenting the injured vertebral body with cement. To overcome the limitations of stand-alone PPSF, it was suggested to augment PPSF with KP as a surgical treatment of TBF. Yet, little is known about the biomechanical alteration occurred to the spine after performing such procedure. The objective of this study was to evaluate and compare the immediate post-operative biomechanical performance of stand-alone PPSF, stand-alone-KP, and KP-augmented PPSF procedures. Novel three-dimensional (3D) finite element (FE) models of the thoracolumbar junction that describes the fractured spine and the three investigated procedures were developed and tested under mechanical loading conditions. The spinal stiffness, stresses at the implanted hardware, and the intradiscal pressure at the upper and lower segments were measured and compared. The results showed no major differences in the measured parameters between stand-alone PPSF and KP-augmented PPSF procedures, and demonstrated that the stand-alone KP may restore the stiffness of the intact spine. Accordingly, there was no immediate post-operative biomechanical advantage in augmenting PPSF with KP when compared to stand-alone PPSF, and fatigue testing may be required to evaluate the long-term biomechanical performance of such procedures.

Biomechanical comparison of posterior intermediate screw fixation techniques with hybrid monoaxial and polyaxial pedicle screws in the treatment of thoracolumbar burst fracture: a finite element study

BACKGROUND

To compare the biomechanical characteristics of different posterior intermediate screw fixation techniques (ISFTs) with hybrid monoaxial pedicle screws (Mps) and polyaxial pedicle screws (Pps) used in thoracolumbar burst fractures.

METHODS

Fixation techniques are compared with regard to the von Mises stress (VMS) of the instrumentations and intradiscal pressures (IDPs) of the adjacent segments by finite element method (FEM).

RESULTS

The redistributed ROM of the fixation models with Pps fixed at the lowest segment was twice of the other fixation models in flexion and extension. The largest value of maximal VMS of a pedicle screw was located at the lowest pedicle screws when Mps are fixed at the lowest segment. The largest value of maximal VMS of the rods was decreased when more Pps are fixed at the models. Maximal IDPs of the upper adjacent segments were all larger than those of the lower adjacent segments. The maximal IDPs of the fixation model with MPs fixed at the lowest segment were larger than the other fixation models in flexion and extension.

CONCLUSIONS

Polyaxial pedicle screws could be placed at the upper or the median segment for the facilitated efficient application of the connecting rod. We should focus on the adjacent segmental degeneration especially the upper adjacent segment in the fixation model with Mps fixed at the lowest segment.

Minimally Invasive Surgery for the Treatment of Traumatic Monosegmental Thoracolumbar Burst Fractures: Clinical and Radiologic Outcomes of 144 Patients With a 6-year Follow-Up Comparing Two Groups With or Without Intermediate Screw

STUDY DESIGN

This was a retrospective study of the clinical and radiologic outcomes of traumatic thoracolumbar (TL) burst fractures.

OBJECTIVES

We aimed to evaluate the clinical and radiologic outcomes after 6 years of follow-up of 144 patients with monosegmental TL burst fractures treated with percutaneous short-segment pedicle screw fixation, comparing two groups with versus without placement of an intermediate screw at the fractured vertebra.

SUMMARY OF BACKGROUND DATA

Traumatic TL fractures are the most common vertebral fractures, especially at the TL junction (T10-L2). Minimally invasive surgery (MIS) is a valuable treatment option for traumatic TL burst fractures.

MATERIALS AND METHODS

The clinical outcomes and radiologic parameters (Cobb angle, midsagittal index, and sagittal index) of 144 patients with traumatic monosegmental TL fractures treated with MIS were evaluated preoperatively, postoperatively, and after 3 and 6 years of follow-up. Patients were categorized into a nonintermediate screw group (nISG) and an intermediate screw group (ISG), and the groups were compared.

RESULTS

There were 71 patients (49.3%) in the nISG and 73 patients (50.7%) in the ISG. The radiologic parameters improved significantly more from the preoperative evaluation to the 6-year follow-up in the ISG than in the nISG (P<0.025). There were no significant differences in the mean Oswestry Disability Index (ODI) and Visual Analog Scale scores at the 6-year follow-up between the ISG and the nISG: 15.6% (ISG) versus 16.8% (nISG) for ODI (P<0.1) and 2.2 (ISG) versus 2.4 (nISG) for Visual Analog Scale score (P<0.85) (P<0.73).

CONCLUSIONS

MIS showed good clinical outcomes 6 years after surgery in both the ISG and the nISG. The additional intermediate screw significantly improved radiologic parameters but not clinical outcomes.

Percutaneous fixation of thoracolumbar vertebral fractures

Surgical treatment of patients with thoracolumbar vertebral fracture without neurological deficit is still controversial.

Management of vertebral fracture with percutaneous fixation was first reported in 2004.

Advantages of percutaneous fixation are: less tissue dissection; decreased post-operative pain; decreased bleeding and operative time (depending on the steep learning curve); better screw positioning with fluoroscopy compared with an open freehand technique; and a decreased infection rate.

The limitations of percutaneous fixation of vertebral fractures include increased radiation exposure to the patient and the surgeon, together with the steep learning curve for this technique.

Adding a screw at the level of the fractured vertebra has the advantages of incorporating fewer motion segments with less operative time and bleeding. This also increases the axial, sagittal and torsional stiffness of the construct.

Percutaneous fixation alone without grafting is sufficient for treating type A and B1 (AO classification) thoracolumbar fractures with satisfactory results concerning kyphosis reduction when compared with open instrumentation and fusion and with open fixation.

Type C and B2 fractures (ligamentous injuries) should undergo fusion since the ligamentous healing is mechanically weak, increasing the risk of instability.

This review offers a detailed description of percutaneous screw insertion and discusses the advantages and disadvantages.

Cite this article: EFORT Open Rev 2018;3:604-613. DOI: 10.1302/2058-5241.3.170026.

Intermediate screws or kyphoplasty: Which method of posterior short-segment fixation is better for treating single-level thoracolumbar burst fractures?

PURPOSE

To compare intermediate screws (IS) with kyphoplasty (KP) in posterior short-segment fixation (PSSF) for patients with single-level thoracolumbar burst fractures.

METHODS

Between 2010 and 2016, 1465 patients were retrospectively reviewed; 48 patients were enrolled with a minimal follow-up of 2 years. Perioperative and functional outcomes were compared. The regional Cobb angle (CA) was included in radiographic analysis. Implant failures or CA correction loss over 10° were regarded as surgical failures. Multiple linear regression was performed to investigate the risk factors of kyphosis recurrence.

RESULTS

Fluoroscopic time (23.7 ± 3.6 vs. 79.3 ± 12.1 s, p < 0.001), operative time (109.6 ± 13.1 vs. 123.8 ± 19.0 min, p = 0.006) and blood loss (104.6 ± 34.9 vs. 129.1 ± 21.7 ml, p = 0.005) were all lower in the IS group. The KP group had lower Visual Analogue Scale scores (3.3 ± 0.9 vs. 2.7 ± 0.8, p = 0.028) and greater anterior body height (ABH) (30.3 ± 9.0 vs. 36.3 ± 11.0%, p = 0.044) after surgery, and less correction loss (5.6 ± 2.7 vs. 0.4 ± 1.2%, p < 0.001). Both groups had a CA correction loss of 4° with a 10% failure rate. The A3 Magerl subclassification, smaller preoperative ABH and smaller postoperative CA had positive correlations with CA correction loss.

CONCLUSION

PSSF with KP provides better back pain relief, greater ABH reduction and less correction loss, while IS has the advantages of less operative time, fluoroscopic time and blood loss. Magerl subclassification of burst fracture is a potential predictor for recurrent kyphosis. Reducing fractured vertebral body height rather than segmental curvature may be more important in PSSF.

STUDY DESIGN

Retrospective, non-randomized controlled study. These slides can be retrieved under Electronic Supplementary Material.

Is Short Same-Segment Fixation Really Better than Short-Segment Posterior Fixation in the Treatment of Thoracolumbar Fractures?

STUDY DESIGN

A retrospective study.

OBJECTIVE

This retrospective study assessed whether short same-segment fixation (SSSF) is better than short-segment posterior fixation (SSPF) for reducing thoracolumbar fractures, improving the kyphosis angle, maintaining vertebral height, or reducing the incidence of broken screws.

SUMMARY OF BACKGROUND DATA

In clinical practice, single-segment thoracolumbar fractures were then more likely to be treated with SSPF that included pedicle fixation at the level of the fracture (short same-segment fixation, or SSSF). Whether SSSF could really achieve vertebral height recovery, improve the kyphosis, reduce postoperative kyphosis loss, and reduce the incidence of internal fixation failure better than SSPF.

METHODS

Patients treated with SSPF or SSSF at our institution during 2006 to 2014 were reviewed. Effects of thoracolumbar fracture reduction, improved kyphosis angle, and maintaining vertebral height were compared between groups. Logistic regression analysis was used to identify factors related to instrumentation breakage and correlation analysis to assess possible relations between loss of correction of the kyphosis angle (LAWAC) and other factors.

RESULTS

Altogether, 130 patients were enrolled (53 SSPF, 77 SSSF). SSPF (22F, 31M) group's mean (range) age was 37.7 (16-60) years, and the follow-up was 26.2 (9-120) months. SSSF (27F, 50M) group's mean (range) age was 39.3 (17-61) years, and the follow-up was 23.2 (9-60) months. All patients underwent either internal fixation or screw repair. Immediately postoperatively, restoration after middle vertebral fractures was better in SSSF patients than in SSPF patients (P = 0.003), with no differences in other fracture-related factors (P > 0.05). Only LAWAC was significantly associated with instrumentation breakage (P < 0.05). Also, immediately postoperatively, the anterior/posterior vertebral heights ratio was negatively related to LAWAC.

CONCLUSION

Pedicle fixation of the fracture did not obtain better recovery of anterior or posterior vertebral heights nor did it improve AWA restoration. There was no significant difference in LAWAC between groups or in the incidence of broken screws. LAWAC may increase the incidence of broken screws.

LEVEL OF EVIDENCE

4.

[To fix the unstable region of sagittal injured unit symmetrically with pedicle screws combined with bone graft fusion for treating thoracolumbar fractures]

Objective

To discuss the security and effectiveness of fixing the unstable region of sagittal injured unit symmetrically with pedicle screws combined with bone graft fusion for treating thoracolumbar fractures.

Methods

A series of 65 patients with a single level thoracolumbar fracture between November 2011 and November 2015 were included in the study. There were 41 males and 24 females with an average age of 36.7 years (range, 23-60 years). The fracture segments included T ₇ 1 case, T ₉ in 2 cases, T ₁₀ in 4 cases, T ₁₁ in 8 cases, T ₁₂ in 14 cases, L ₁ in 19 cases, L ₂ in 13 cases, L ₃ in 3 cases, and L ₄ in 1 case. According to AO classification, there were 34 cases classified as type A, 27 cases type B, and 4 cases type C. The neurological function was evaluated by American Spinal Injury Association (ASIA) grade score, there were 1 case at grade A, 2 cases grade B, 6 cases grade C, 15 cases grade D, and 41 cases grade E. The thoracolumbar injury severity score (TLICS) was 4 in 9 cases, 5 in 29 cases, 6-8 in 23 cases, 9-10 in 4 cases. The time form injury to operation was 2-12 days (mean, 5.3 days). The fractured vertebra, along with the superior and inferior discs were defined as a injured unit and divided into three parts on the sagittal position: region Ⅰ mainly including the superior disc, cephalic 1/3 of injured vertebra, and posterior ligamentous complex as to oppose; region Ⅱ mainly including the middle 1/3 of injured vertebra, pedicles, lamina, spinous process, and supraspinal ligament; region Ⅲ mainly including the inferior disc, caudal 1/3 of injured vertebra, and posterior ligamentous complex as to oppose. The unstable region was defined as the key injured region of the vertebra. Pedicle screws were fixed symmetrically and correspondingly with bone grafting to treat thoracolumbar fractures. The neurological status, ratio of anterior body height, and sagittal Cobb angle were collected at preoperation, immediate after operation, and last follow-up to evaluate surgical and clinical outcomes.

Results

All patients accepted operation safely and were followed up 12-24 months (mean, 17.3 months). Cerebrospinal fluid leakage occurred in 3 patients, and cured by symptomatic treatment. There was no complications such as loosening, displacement, and breakage of internal fixator. Bony fusion was achieved in all patients at 10-13 months (mean, 11.4 months) after operation. At last follow-up, according to ASIA grading, 1 case was grade A, 1 grade B, 3 grade C, 9 grade D, and 51 grade E, showing significant difference when compared with preoperative data ( Z=-2.963, P=0.014). The ratio of anterior body height at preoperation, immediate after operation, and last follow-up were 53.2%±6.8%, 91.3%±8.3%, 89.5%±6.6% respectively; and the sagittal Cobb angle were (16.3±8.1), (2.6±7.5), (3.2±6.8)° respectively. The ratio of anterior body height and the sagittal Cobb angle at immediate after operation and at last follow-up were significantly improved when compared with preoperative values ( P<0.05), but no significant difference was found between at immediate after operation and at last follow-up ( P>0.05).

Conclusion

It is safe and reliable to treat thoracolumbar fractures under the principle of fixing the unstable region of injured unit symmetrically with pedicle screws combined with bone grafting.

A Comparison of Three Different Methods of Fixation in the Management of Thoracolumbar Fractures

Background

Management of thoracolumbar fractures remains controversial in the literature. The primary aims of this study were to assess different levels of fixation with respect to radiological outcomes in terms of fracture reduction and future loss of correction.

Methods

This is a single center, retrospective study. Fifty-five patients presenting with thoracolumbar fractures between January 2012 and December 2015 were analyzed in the study. The levels of fixation were divided in 3 groups: 1 vertebra above and 1 below the fracture (1/1), 2 above and 2 below (2/2), and 2 above and 1 below (2/1).

Results

The most common mechanism was high fall injury, and the most common vertebra L1. Burst fractures were the ones with the highest incidence. The 2/2 fixation achieved the best reduction of the fracture, but with no statistical significance. The correction is maintained better by the 2/2 fixation, but there is no statistical difference compared to the other fixations. Insertion of screws at the fracture level did not improve outcomes.

Conclusion

The data of this study identified a trend toward better radiological outcomes for fracture reduction and maintenance of the correction in the 2/2 fixations. However, these results are not statistically significant. Future multicenter prospective clinical trials are needed in order to agree on the ideal management and method of fixation for thoracolumbar fractures.

Combined pedicle screw fixation at the fracture vertebrae versus conventional method for thoracolumbar fractures: A meta-analysis

BACKGROUND

Thoracolumbar fractures is a frequent injury occurring in spinal trauma. Outcomes and complications between combined pedicle screw fixation at the fracture vertebrae (AFV) and conventional method cross the fracture vertebrae (CFV) are still controversial. Thus, this study aimed to evaluate differences in outcome variables between these two operative methods.

MATERIALS AND METHODS

PubMed, Web of Science, Cochrane Library, EMBASE and CNKI were searched with the terms "thoracolumbar fractures", "posterior", "pedicle screw fixation", and "clinical trial" from Jan 1980 to July 2017. Two reviewers independently screened the studies for eligibility, evaluated the quality and extracted data from eligible studies, with confirmation by cross-checking. The major results and conclusions were concluded, and the different complication rates and functional outcomes were compared. Meta-analysis was performed using RevMan 5.3 software.

RESULTS

Eighteen randomized controlled trials involving 1280 patients were eligible. The pooled data revealed that AFV group might be associated with more intraoperative blood loss (MD = 9.84, 95%CI 7.45 to 12.22) and longer operation time (MD = 1.97, 95%CI 0.17 to 3.77) when compared with CFV group. However, AFV group significantly improved visual analogue scale (VAS) (MD = -1.27, 95%CI -1.70 to -0.83), anterior vertebral height (AVH) (MD = 7.58, 95%CI 3.99 to 11.17), short-term Cobb angle (MD = -1.29, 95%CI -2.39 to -0.19), long-term Cobb angle (MD = -4.47, 95%CI -7.30 to -1.63) and loss of long-term correction efficacy (MD = -6.56, 95%CI -7.49 to -5.62) after surgery. Moreover, compared with the CFV group, the AFV group had lower rate of implant failure (MD = 0.16, 95%CI 0.07 to 0.36). Both techniques had similar hospital stay (MD = 0.25, 95%CI -0.52 to 1.03) and postoperative infection (MD = 0.53, 95%CI 0.13 to 2.23).

CONCLUSIONS

Though with a more operation time and intraoperative hemorrhage, combined pedicle screw fixation at the fracture veterbrae may be better than traditional fixation cross the fracture level alone for thoracolumbar fractures.

A Comparison of Three Different Methods of Fixation in the Management of Thoracolumbar Fractures

Introduction

Management of thoracolumbar fractures remains controversial in the literature. The primary aims of this study were to assess different levels of fixation with respect to radiological outcomes in terms of fracture reduction and future loss of correction.

Methods

This is a single center, retrospective study. Fifty-five patients presenting with thoracolumbar fractures between January 2012 and December 2015 were analyzed in the study. The levels of fixation were divided in 3 groups, 1 vertebra above and 1 below the fracture (1/1), 2 above and 2 below (2/2), and 2 above and 1 below (2/1).

Results

The most common mechanism was high fall injury and the most common vertebra L1. Burst fractures were the ones with the highest incidence. The 2/2 fixation achieved the best reduction of the fracture but with no statistical significance. The correction is maintained better by the 2/2 fixation but there is no statistical difference compared to the other fixations. Insertion of screws at the fracture level did not improve outcomes.

Conclusion

The data of this study identified a trend towards better radiological outcomes for fracture reduction and maintenance of the correction in the 2/2 fixations. However these results are not statistically significant. Future multicenter prospective clinical trials are needed in order to agree on the ideal management and method of fixation for thoracolumbar fractures.

Assessment of variability in Turkish spine surgeons' trauma practices

OBJECTIVES

The aim of this study was to analyse the variability among Turkish spinal surgeons in the management of thoracolumbar fractures by carrying out a web survey.

METHODS

An invitation text and web-link of the survey were sent to the members of the Turkish Spine Society mail group. A fictitious spine trauma vignette, a 23 year-old male with a L1 burst fracture, was presented and 25 questions were asked to participants. Variability of answers in a given question was assessed with the Index of Qualitative Variation (IQV). Questions with high IQV values (>%80) were selected to evaluate the relation between participant factors (speciality, age, degree and experience level of the surgeon, type of the work centre and volume of the trauma patients).

RESULTS

Sixty-four (88%) among the 73 participating surgeons completed the survey. 45 (70%) of them were orthopaedic surgeons and 19 (30%) were neurosurgeons. 11 questions had very high variability (IQV ≥ 0.80), 5 had high variability (0.58-0.75) and 2 had low variability (IQV≤0.20). The question with the highest variability was related to the use of brace after surgery (IQV = 0.93). Following one was about the selection of fixation levels (IQV = 0.91). Neurosurgeons were more likely to use brace postoperatively and professors were less likely to perform decompression.

CONCLUSION

This survey shows that thoracolumbar spine trauma practice significantly varies among Turkish spine surgeons. Surgeons' characteristics affected some specific answers. Lack of enough knowledge about spine trauma care, fracture classifications and surgical techniques and/or ethical factors may be other reasons for this variability.

Radiologic and Functional Outcomes in Unstable Thoracolumbar Fractures Treated With Short-segment Pedicle Instrumentation

STUDY DESIGN

A retrospective review of radiographs, clinical charts, and health questionnaires of 40 patients.

OBJECTIVE

To evaluate the radiologic and functional results of unstable thoracolumbar fractures treated with short-segment pedicle instrumentation (SSPI).

A SUMMARY OF BACKGROUND DATA

Although earlier publications report a risk of correction loss or material failure after short-segment fixation in unstable thoracolumbar fractures, more current data suggest that improvements in this technique could offer good clinical and radiologic results.

MATERIALS AND METHODS

We undertook a retrospective review of 40 patients with unstable thoracolumbar fractures treated with SSPI. Radiographs and computed tomogrphic scans were analyzed to determine fracture classification and sagittal plane deformity, estimated by the Cobb method. The rates of final kyphosis and correction loss and their relationship with the Load Sharing Classification (LSC) and the AO classification were analyzed. We reviewed the hospital charts to identify complications and outcomes. At the final follow-up, the Short-Form 36 health survey was carried out to evaluate the functional outcome. The relationship between conditions such as polytrauma, neurological compromise or fracture site, and radiological and functional outcomes was also analyzed.

RESULTS

We observed mean values of 5.9 degrees of final follow-up kyphosis and 5.1 degrees of correction loss. One case of material failure was seen. The severity in the LSC or the AO classification, polytrauma, neurological compromise, or fracture site had no relationship with worse radiologic or functional outcomes.

CONCLUSIONS

SSPI shows good results in fracture reduction, with good functional outcomes despite the loss of correction seen at the final follow-up. Although no investigated variable was found to be predictive of radiographic failure, a trend was identified (P=0.07) that patients with a higher LSC had an increased loss of correction.

Effectiveness of pedicle screw inclusion at the fracture level in short-segment fixation constructs for the treatment of thoracolumbar burst fractures: a computational biomechanics analysis

When treating thoracolumbar burst fractures (BF), short-segment posterior fixation (SSPF) represents a less invasive alternative to the traditional long-segment posterior fixation (LSPF) approach. However, hardware failure and loss of sagittal alignment have been reported in patients treated with SSPF. Including pedicle screws at the fracture level in SSPF constructs has been proposed to improve stiffness and reliability of the construct. Accordingly, the biomechanical performance of the proposed construct was compared to LSPF via a computational analysis. Pedicle screws at fracture level improved the performance of the short-segment construct. However, LSPF still represent a biomechanically superior option for treating thoracolumbar BF.

Temporary short-segment pedicle screw fixation for thoracolumbar burst fractures: comparative study with or without vertebroplasty

BACKGROUND CONTEXT

Short-segment posterior spinal instrumentation for thoracolumbar burst fracture provides superior correction of kyphosis by an indirect reduction technique, but it has a high failure rate.

PURPOSE

The purpose of the study we report here was to compare outcomes for temporary short-segment pedicle screw fixation with vertebroplasty and for such fixation without vertebroplasty.

STUDY DESIGN

This is a prospective multicenter comparative study.

PATIENT SAMPLE

We studied 62 consecutive patients with thoracolumbar burst fracture who underwent short-segment posterior instrumentation using ligamentotaxis with Schanz screws with or without vertebroplasty.

OUTCOME MEASURES

Radiological parameters (Cobb angle on standing lateral radiographs) were used.

METHODS

Implants were removed approximately 1 year after surgery. Neurologic function, kyphotic deformity, canal compromise, and fracture severity were evaluated prospectively.

RESULTS

After surgery, all patients with neurologic deficit had improvement equivalent to at least one grade on the American Spinal Injury Association impairment scale and had fracture union. Kyphotic deformity was reduced significantly, and reduction of the vertebrae was maintained with and without vertebroplasty, regardless of load-sharing classification. Although no patient required additional anterior reconstruction, kyphotic change was observed at disc level mainly after implant removal with or without vertebroplasty.

CONCLUSIONS

Temporary short-segment fixation yielded satisfactory results in the reduction and maintenance of fractured vertebrae with or without vertebroplasty. Kyphosis recurrence may be inevitable because adjacent discs can be injured during the original trauma.

Treatment of thoracolumbar burst fractures by short-segment pedicle screw fixation using a combination of two additional pedicle screws and vertebroplasty at the level of the fracture: a finite element analysis

Background

Traditional one-above and one-below four-screw posterior short-segment instrumentation is used for unstable thoracolumbar burst fractures. However, this method has a high rate of implant failure and early loss of reduction. The purpose of this study was to use finite element (FE) analysis to determine the effect of treating thoracolumbar burst fractures by short-segment pedicle screw fixation using a combination of two additional pedicle screws and vertebroplasty at the level of the fracture.

Methods

An intact T11-L1 spine FE model was created from the computed tomography images of a male subject. Four fixation models with posterior fusion devices (pedicle screws, rods, cross-link) were established to simulate an unstable thoracolumbar fracture with different fusion surgeries: short-segment fixation with: 1) a link (S-L); 2) intermediate bilateral screws (S-I); 3) a link and calcium sulfate cement (S-L-C); 4) intermediate bilateral screws and calcium sulfate cement (S-I-C). Different loading conditions (flexion, extension, lateral bending, and axial rotation) were applied on the models and analyzed with a FE package. The range of motion (ROM), and the maximum value and distribution of the implant stress, and the stress in the facet joint, were compared between the intact and fixation models.

Results

The ROM in flexion, extension, axial rotation, and lateral bending was the smallest in the S-I-C model, followed by the S-I, S-L-C, and S-L models. Maximum von Mises stress values were larger under lateral bending and axial rotation loadings than under flexion and extension loading. High stress was concentrated at the crosslink and rod junctions. Maximal von Mises stress on the superior vertebral body for all loading conditions was larger than that on the inferior vertebral body. The maximal von Mises stress of the pedicle screws during all states of motion were 265.3 MPa in S-L fixation, 192.9 MPa in S-I fixation, 258.4 MPa in S-L-C fixation, and 162.3 MPa in S-I-C fixation.

Conclusions

Short-segment fixation with two intermediate pedicle screws together with calcium sulfate cement at the fractured vertebrae may provide a stiffer construct and less von Mises stress of the pedicle screws and rods as compared to other types of short-segment fixation.

Posterior short-segment fixation in thoracolumbar unstable burst fractures - Transpedicular grafting or six-screw construct?

OBJECTIVES

Early implant failure and donor-site complication remain a concern in patients with thoracolumbar burst fracture underwent one-above and-below short-segment posterior pedicle screw fixation with fusion. Our aim was to evaluate the results of short-segment pedicle instrumentation enforced by two augmenting screws or injectable artificial bone cement in the fractured vertebra, and compare the differences between these two PATIENTS AND METHODS: We conducted a retrospective clinical and radiographic study. Twenty-seven patients were treated with a six-screw construct (group 1), and twenty-nine patients underwenta four-screw construct and fractured vertebra augmentation by injectable calcium sulfate/phosphate cement (group 2). Posterior or posterolateral fusions were not performed in both groups. The severity of the fractured vertebra was evaluated by the load-sharing classification (LSC). Local kyphosis and anterior body height of the fractured vertebra were measured and were follow-up at least 2 years. Any implant failure or loss of correction >10° degrees at the final was defined as failure of surgery. Patients' clinical results were assessed by the Denis scale.

RESULTS

Blood loss and operation time were less in group 1 (126.2±9.7 vs. 267.6±126.1ml, p<0.001 and 141.2±48.7 vs. 189.8±16.4min, p<0.001). Immediately after surgery, group 2 had a better local kyphosis angle (3.7±5.3 vs.6.0±4.1°, p=0.047) and acquired more anterior body height (94.9%±7.6% vs. 84.9%±10.0%, p<0.001). Both groups had similar clinical results (pain score: 1.5±0.8vs. 1.4±0.6, p=0.706; work score: 1.7±0.9 vs. 1.6±1.0, p=0.854). Group 1 had 3 cases of surgery failure; group 2 had 8 cases of implant failure (p=0.121). The average LSC score of these 11 patients with surgical failure was 7.2.

CONCLUSION

Thesix-screw construct had the advantage of shorter operating time, less blood loss, and lower failure rate. For those patients with anLSC score ≧7, posterior short-segment instrumentation should be used cautiously.

Pedicle screw fixation combined with intermediate screw at the fracture level for treatment of thoracolumbar fractures: A meta-analysis

BACKGROUND

Use of a pedicle screw at the level of fracture, also known as an intermediate screw, has been shown to improve clinical results in managing thoracolumbar(TL) fractures, but there is a paucity of powerful evidence to support the claim. The aim of this study was to compare outcomes between pedicle screw fixation combined with intermediate screw at the fracture level and conventional pedicle screw fixation (one level above and one level below the fracture level) for thoracolumbar (TL) fractures.

METHODS

A meta-analysis of cohort studies was conducted between pedicle screw fixation combined with intermediate screw at the fracture level (combined screw group) and conventional pedicle screw fixation (conventional group) for the treatment of TL fractures from their inception to December 2015. An extensive search of studies was performed in PubMed, Medline, Embase, and the Cochrane library. The following outcome measures were extracted: visual analogue scale (VAS), operation time and intraoperative blood loss, Cobb angle and anterior vertebral height (AVH), and complications. Data analysis was conducted with RevMan 5.3.5.

RESULTS

From 10 relevant studies identified, 283 patients undergoing pedicle screw fixation combined with intermediate screw at the fracture level were compared with 285 conventional pedicle screw procedures. The pooled analysis showed that there was statistically significant difference in terms of postoperative Cobb angle (95% confidence interval (CI), -3.00, -0.75; P = 0.001) and AVH (95% CI, 0.04, 12.23; P = 0.05), correction loss (Cobb angle: P < 0.0001; AVH: P < 0.0001) and implant failure rate (95% CI, 0.06, 0.62; P = 0.006), and blood loss (W 95% CI, 2.22, 23.60; P = 0.02) between 2 groups. But in terms of other complications, there were no differences between 2 groups (95% CI, 0.23, 2.04; P = 0.50). No difference was found in operation time (95% CI, -5.36, 14.67; P = 0.36) and VAS scores (95% CI, -0.44, 0.01; P = 0.06).

CONCLUSIONS

The combined screw fixation technique was associated with better reduction of the fractured vertebrae, less correction loss in the follow-up, and lower implant failure rate. Given the lack of robust clinical evidence, these findings warrant verification in large prospective registries and randomized trials with long-term follow-up.

Effect of the percutaneous pedicle screw fixation at the fractured vertebra on the treatment of thoracolumbar fractures

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of percutaneous pedicle screw fixation at the fractured vertebra in the treatment of thoracolumbar fractures.

METHODS

Thirty-two consecutive patients were enrolled in the study. All patients received percutaneous pedicle screw fixation, and they were randomly divided into two groups to undergo either the placement of pedicle screws into the fractured vertebra (fractured group) or not (control group). The operation time and intra-operative blood loss were recorded. Oswestry disability index (ODI) questionnaire and visual analogue scale (VAS) as clinical assessments were quantified. Radiographic follow-up was defined by the vertebral body index (VBI), anterior vertebral body height (AVBH), and Cobb angle (CA).

RESULTS

No significant difference was observed in the operation time and intra-operative blood loss between the two groups. Clinical results (VAS and ODI scores) showed no significant difference during all the follow-up periods. In the fractured group, there were better correction and less loss of AVBH and VBI compared with the control group. However, post-operative correction of the CA immediately after surgery and the correction loss at the final follow-up showed no significant difference between the two groups.

CONCLUSION

Percutaneous screw fixation combined with intermediate screws at the fractured vertebra could more effectively restore and maintain fractured vertebral height, and is an acceptable, minimally invasive surgical choice for patients with type A thoracolumbar fractures.

Minimally Invasive Spine Metastatic Tumor Resection and Stabilization: New Technology Yield Improved Outcome

Spinal metastases compressing the spinal cord are a medical emergency and should be operated on if possible; however, patients' medical condition is often poor and surgical complications are common. Minimizing surgical extant, operative time, and blood loss can potentially reduce postoperative complications. This is a retrospective study describing the patients operated on in our department utilizing a minimally invasive surgery (MIS) approach to decompress and instrument the spine from November 2013 to November 2014. Five patients were operated on for thoracic or lumbar metastases. In all cases a unilateral decompression with expandable tubular retractor was followed by instrumentation of one level above and below the index level and additional screw at the index level contralateral to the decompression side. Cannulated fenestrated screws were used (Longitude FNS) and cement was injected to increase pullout resistance. Mean operative time was 134 minutes and estimated blood loss was minimal in all cases. Improvement was noticeable in neurological status, function, and pain scores. No complications were observed. Technological improvements in spinal instruments facilitate shorter and safer surgeries in oncologic patient population and thus reduce the complication rate. These technologies improve patients' quality of life and enable the treatment of patients with comorbidities.

Definitive single-stage posterior surgical correction of complete traumatic spondyloptosis at the thoracolumbar junction

Complete dislocation at the thoracolumbar junction is a rare occurrence, with only 4 previously reported cases in 3 separate series. Surgical procedures in the reported cases of spondyloptosis at the thoracolumbar junction have been described using instrumentation, reduction, decompression, and stabilization techniques. In this report the authors' patient presented with spondyloptosis at the thoracolumbar junction, resulting in a T-11 American Spinal Injury Association Grade A injury. The authors corrected the patient's thoracolumbar spondyloptosis with surgical reconstruction without the use of leveraged instrumented reduction. They describe a single-stage, posterior-only spinal realignment, reconstruction, and stabilization. Within months of beginning postoperative therapy, the patient enrolled and attended courses at a local college and regained personal independence by learning to drive a motor vehicle with a hand control. Two-year radiographic and clinical follow-up confirms solid fusion across the reconstruction.