Posterior short-segment fixation including the fractured vertebra for severe unstable thoracolumbar fractures / 中国修复重建外科杂志

Objective: To discuss the effectiveness of posterior short-segment fixation including the fractured vertebra for severe unstable thoracolumbar fractures using pedicle screw fixation.

Nine issues about clinical application of thoracolumbar injury classification and severity score / 中华创伤骨科杂志

Spinal fractures are a big challenge to orthopedists.Thoracolumbar Injury Classification and Severity Score (TLICS),a newly developed evaluation system for thoracolumbar fractures,has proved to be valid and reliable in the last decade.However,there have still been many problems in the clinical application of TLICS in China.We discussed nine issues about the clinical application of TLICS in this article,hoping to promote better understanding and application of TLICS in Chinese spinal surgeons in their daily practice.

Nine issues about clinical application of thoracolumbar injury classification and severity score / 中华创伤骨科杂志

Spinal fractures are a big challenge to orthopedists.Thoracolumbar Injury Classification and Severity Score (TLICS),a newly developed evaluation system for thoracolumbar fractures,has proved to be valid and reliable in the last decade.However,there have still been many problems in the clinical application of TLICS in China.We discussed nine issues about the clinical application of TLICS in this article,hoping to promote better understanding and application of TLICS in Chinese spinal surgeons in their daily practice.

The Outcomes of Short and Long Segment Posterior Instrumentation of Thoracolumbar Burst Fractures with a Load Sharing Score of 7 or More

STUDY DESIGN: Retrospective. OBJECTIVES: To investigate outcomes between short and long segment posterior instrumentation of thoracolumbar burst fractures with a load sharing score of 7 or more. SUMMARY OF LITERATURE REVIEW: Short segment instrumentation has been recommended in thoracolumbar burst fractures with a load sharing score of 6 or less, and long segment instrumentation has been recommended for those with a score of 7 or more. However, this standard is controversial. MATERIALS AND METHODS: From March 2006 to January 2014, 45 patients with thoracolumbar fractures with a load sharing score of 7 or more were treated with posterior instrumentation. They were divided into two groups: short (group S) and long segment (group L) groups. Radiologic results were evaluated on the basis of the kyphotic angle and anterior column height. Complications were also reviewed. RESULTS: Groups S and L consisted of 13 and 32 patients and had mean ages of 48.3 and 47.3 years, respectively. In group S, the anterior column height increased from 56.62% to 76.23% postoperatively, and remained at 71.15% at follow-up. The kyphotic angle decreased from 16.27degrees to 7.55degrees postoperatively, and was 13.17degrees at follow-up. In group L, the anterior column height recovered from 49.67% to 70.52% postoperatively, and was 63.73% at follow-up. The kyphotic angle decreased from 20.08degrees to 6.80degrees postoperatively, and was 14.18degrees at follow-up. The changes in the anterior column height and kyphotic angle were not significantly different between groups S and L. Seven cases had complications and the number of cases with complications was not significantly different between groups S and L. CONCLUSIONS: Short and long segment instrumentation of thoracolumbar fractures with a load sharing score of 7 or more did not achieve significantly different results.

Radiological Outcome of Short Segment Posterior Instrumentation and Fusion for Thoracolumbar Burst Fractures

STUDY DESIGN: Retrospective study. PURPOSE: To evaluate the radiological outcome of the surgical treatment of thoracolumbar burst fractures by using short segment posterior instrumentation (SSPI) and fusion. OVERVIEW OF LITERATURE: The optimal surgical treatment of thoracolumbar burst fractures remains a matter of debate. SSPI is one of a number of possible choices, yet some studies have revealed high rates of poor radiological outcome for this SSPI. METHODS: Patients treated using the short segment instrumentation and fusion technique at the Spinal Injuries Center (Iizuka, Fukuoka, Japan) from January 1, 2006 to July 31, 2012 were selected for this study. Radiographic parameters such as local sagittal angle, regional sagittal angle, disc angle, anterior or posterior height of the vertebral body at admission, postoperation and final observation were collected for radiological outcome evaluation. RESULTS: There were 31 patients who met the inclusion criteria with a mean follow-up duration of 22.7 months (range, 12-48 months). The mean age of this group was 47.9 years (range, 15-77 years). The mean local sagittal angles at the time of admission, post-operation and final observation were 13.1degrees, 7.8degrees and 14.8degrees, respectively. There were 71% good cases and 29% poor cases based on our criteria for the radiological outcome evaluation. The correction loss has a strong correlation with the load sharing classification score (Spearman rho=0.64, p<0.001). CONCLUSIONS: The loss of kyphotic correction following the surgical treatment of thoracolumbar burst fracture by short segment instrumentation is common and has a close correlation with the degree of comminution of the vertebral body. Patients with high load sharing scores are more susceptible to correction loss and postoperative kyphotic deformity than those with low scores.

Biomechanical Comparison Analysis of Cervical Plate Systems for Anterior Cervical Discectomy and Fusion: Constrained vs. Semi-constrained Systems / 대한골다공증학회지

The purpose of this study were to constructed multi-level cervical spine finite element (FE) model and to investigate changes in load distribution and range of motion (ROM) at index level and adjacent levels at immediately after anterior cervical discectomy and fusion (ACDF) and after full bony union using constrained and semi-constrained cervical plate systems(dynamic plate, variable screw). A FE model of intact cervical spine (C3-6) was created from computer tomography (CT) images of the healthy adult (male, 26 years, no pathologies). The post-op FE models (C5-6 with ACDF, cage with bone graft) were constructed by modifying a intact cervical FE model. Four different configurations of the model were considered: Type 1-Rigid plate+Fixed screw, Type II-Rigid plate + Variable screw, Type III-Dynamic plate + Fixed screw, Type IV-Dynamic plate + Variable screw. The bone-cage and bone screw interface behavior were accomplished via 'tie' contact condition and friction coefficient of 0.2 to assume fusion and non-fusion, respectively. The inferior endplate of C6 vertebral body was constrained in all directions. Loading condition used hybrid protocol with follower load of 73.6N at superior endplate of C3 vertebral body. In non-fusion cases, load at the bone graft increased from Type I to IV (2.3

Comparison of Short Segment and Long Segment Posterior Instrumentation of Thoracolumbar and Lumbar Bursting Fractures at Load Sharing Score 7 or Above

STUDY DESIGN: A retrospective comparative analysis of the short-segment and long-segment posterior fixation in thoracolumbar burst fractures that are 7 points or above in load-sharing score was performed. OBJECTIVES: The purpose of this study is to demonstrate the appropriate level of fixation by comparing the results of short-segment and long-segment posterior fixation. SUMMARY OF LITERATURE REVIEW: There is general consensus that short-segment fixation should be done in thoracolumbar burst fractures that are 6 points or less in load-sharing classification. There is some controversy regarding whether short-segment or long-segment fixation should be done in thoracolumbar burst fractures that are 7 points or above in load-sharing classification. MATERIALS AND METHODS: From 1998 through 2008, 32 patients with thoracolumbar burst fractures above 7 points in load-sharing classification had been operated with short-segment (1 segment above and 1 segment below: 23 patients) or long-segment (2 segments above and 1 segment below: 9 patients) transpedicular screw fixation at the author's institution. They were divided by two groups (group I: short-segment fixation, group II: long-segment fixation). The mean age of patients was 49.2 years old and the mean follow-up period was 2.4 years (1-7 years). In preoperative and postoperative simple radiographs, the bony unions, breakages or loosening of implants were assessed, and the losses of correction angle and anterior vertebral body height were measured. RESULTS: In all cases, non-union or loosening of implants were not observed. There was 1 screw breakage in short-segment fixation group during the follow up period, but bony union was obtained at final follow-up. The mean score of load sharing classification was 7.3 in Group I and 7.1 in Group II, and there was no significant difference between two groups. (p>0.05) The mean anterior vertebral body height loss was 5.3% in Group I and 3.6% in Group II and the mean loss of correction angle were 4.72 in Group I and 3.38 in Group II. There was no significant difference between the two groups for both. (p>0.05) CONCLUSIONS: There was no significant difference in radiologic parameters between two groups. Short-segment fixation could be used successfully in selected cases of thoracolumbar burst fractures that are 7 points or above in load-sharing classification.

The Efficacy of the Treatment of Thoracolumbar Spine Fractures with Short-segment Posterior Instrumentation and Fusion

PURPOSE: To evaluate the safety and usefulness of the short-segment posterior instrumentation and fusion in the treatment of thoracolumbar spine fractures. MATERIALS AND METHODS: Forty-two patients were treated by short-segment pedicle screw instrumentation and fusion between Oct. 1998. and Jan. 2004 by single surgeon. All patients were treated posteriorly and all the pedicle screws are monoaxial. Intraoperative rod bending and fixation technique was used to reduce the collapsed vertebral body and correct the kyphotic angle. The follow up duration is mean 2.1 year (1~6 year). The mean age is 40.2 year (18~60 year) old. The fractures were classified by Denis' classification and Load-Sharing Classification. Preoperative and postoperative changes of kyphotic angle and vertebral body height were measured. Denis' Pain Score and Work scales, Frankel neurologic grade were obtained during follow-up evaluation for patients. RESULTS: All the cases got solid bony union. Mean Load-Sharing Score was 7.3. Clinical results were good. The mean kyphotic angle was preoperatively 14.5 degree, immediate postoperatively 7.5 degree, and last follow up 9.2 degree. The mean anterior vertebral heights s were 60.8% preoperatively, 83.4% immediate postoperatively, and 79.5% last follow up. There was only one case of screw breakage but no revision operation due to loss of reduction. All the cases showed satisfactory clinical results. CONCLUSION: This study suggest that short-segment instrumentation and fusion using pedicle screw system for thoracolumbar spine fractures could lead to good results, if comminution of vertebral body is considered in the selection of approach.

Posterior Short-Segment Instrumentation of Thoracic and Lumbar Bursting Fractures: Retrospective study related with Load-Sharing classification / 대한척추외과학회지

STUDY DESIGN: The authors designed the retrospective study with the Load-Sharing Classification in 47cases of the bursting thoracic-lumbar fractures, which were operated using the pedicle screws. OBJECTIVE: To judge the effectiveness of posterior short segment instrumented fusion in thoracic-lumbar fractures according to the Load-Sharing classification. MATERIAL AND METHOD: From 1995 through 1998, 47 patients who had been operated with short segment transpedicular instrumentation including fractured vertebra were selected and they were divided two groups, one below 6 point of Load-Sharing score, the other above 7 point. In follow up of average 39 months, the guide of reduction loss, which include the change of anterior vertebral body height and sagittal index were analysed statistically with the Student T-test at the postoperative time and the last follow-up time. RESULTS: In group below 6 point, the average of anterior vertebral body height was 56.2% before the operation and reduced 77.6% after the operation and measured 76.4% at final follow-up. The reduction loss was 1.2%. The sagittal index of preoperative 19.4degree became 10.6degree after the operation and measured 11.8degree at the last follow-up. The loss of correction angle was 1.2degree . In the other group above 7 point, anterior vertebral body height was average 51.7% before the operation and reduced 75% after the operation and measured 71.2% in last follow up, so reduction loss was 3.8%. Sagittal index was average 21.6degree before the operation and corrected 12.6 after the operation and measured 14.6degree in last follow up. All of 19 patients with neurologic deficits improved by over the one Frankel grade except grade A. CONCLUSION: Although the additional study is needed, there were no significant difference of statistical analysis about indexes between two groups.

Combined Approach Operation for the Lumbar Spine Fractures according to 'The Load-sharing Classification'

BACKGROUND:Lumbar spine fractures treated conservatively or operatively may result in severe kyphotic deformity. Reliable operation plan should be made to prevent the development of delayed kyphosis in unstable lumbar spine fracture. STUDY DESIGN: Between September 1995 and March 1997, twelve cases with highly unstable lumbar spine fractures (7 according to'Load-sharing classification score') or fracture-dislocations were operated with combined retroperitoneal and posterior approach. The patients underwent anterior corpectomy, interbody fusion and short segment fixation with posterior transpedicular screws(1 level above and 1 level below). All patients were operated on the same day except one case. The patients were followed-up at least 12 months and mean follow-up period was 17.2 months after operation. The kyphotic angle was measured by Salter's method preoperative, immediate postoperative and at 12 months. RESULTS: There were 9 cases of burst fractures and 3 cases of fracture-dislocations. The mean kyphotic angle was 24degrees preoperatively, -5degrees postoperatively and -2degrees at 12 months follow-up. This means the patients regained normal lumbar lordosis after the operation and maintained on long term follow-up. There was no case of pseudoarthrosis or delayed kyphosis development during follow-up period. CONCLUSIONS: Highly unstable lumbar spine fracture with high load-sharing classification score could be treated to achieve normal lumbar lordosis immediate postoperatively and prevent kyphotic deformity on long-term follow-up evaluation with combined approach.

The Effect of Load Sharing Wiring on the Fixation of Transverse Fracture of Porcine Patella / 대한정형외과연구학회지

Among many kinds of internal fixation techniques for the transverse fracture of the patella, AO modified tension band wiring technique and Pyrford technique have been widely used. However, it seems that those techniques are not strong enough to withstand immediate full weight bearing and full range of motion exercise postoperatively. Instead, a load sharing wiring technique seems to be more effective fixation technique. A comparative study was performed to evaluate the load sharing wiring technique using porcine patellae. Transverse fractures of thirty knees were made and were fixed with 3 different fixation technique. 1) AO modified tension band wiring technique, 2) Pyrford technique, and 3) Load sharing wiring technique. Then, those knees were mounted on the material testing system (Instron 4204(R)) and longitudinal traction was applied. The result showed that the separation of the fracture fragments was much less with the load sharing wiring technique than with the AO modified tension band wiring technique and the Pyrford tehchnique when 5 kg to 25 kg of traction was applied(P<0.05). The load sharing wiring technique showed less than 0.4mm of separation at 25~50kg of traction, where other techniques led specimen to failure. From this study, it was suggested that the load sharing wiring technique was proved to be more effective fixation technique compared to other techniques.