Clinical Study of Accelerated Rehabilitation Concept Combined with Tianji Robot-Assisted Surgery in Lumbar Degenerative Diseases

Objective: To compare the effectiveness and safety of two surgical methods for lumbar degenerative diseases;the combination of the concept of accelerated rehabilitation with the assistance of Tianji Robotics and the concept of accelerated rehabilitation combined with manual pedicle screw placement assisted by conventional C-arm fluoroscopy. Methods: A retrospective analysis was performed on 70 patients who received the concept of accelerated rehabilitation combined with spinal surgery for lumbar degenerative diseases in Baise People’s Hospital from January 2022 to January 2024. Among them, 35 patients in the robot group received accelerated rehabilitation concept combined with robot-assisted surgery;In the conventional C-arm group, 35 patients received the accelerated rehabilitation concept combined with manual pedicle screw placement assisted by conventional C-arm fluoroscopy. VAS score (preoperative/postoperative), ODI score (preoperative/postoperative), intraoperative bleeding volume, postoperative hospital stay, postoperative complications and the accuracy rate of screw placement were compared between the two groups. Result: There was no statistically significant difference in preoperative VAS scores between the robot group and the conventional C-arm group (6.45 ± 0.82 VS 6.63 ± 0.81, P = 0.6600). The postoperative VAS score of the robot group was better than that of the conventional C-arm group (1.69 ± 0.80 VS 2.45 ± 0.85, P = 0.0000*). There was no statistically significant difference in preoperative ODI scores between the robot group and the conventional C-arm group (32.11 ± 3.18 VS 31.66 ± 2.25, P = 0.4900). The postoperative ODI score of the robot group was better than that of the conventional C-arm group (22.68 ± 1.94 VS 24.57 ± 2.25, P = 0.0000*). The postoperative complications in the robot group were less than those in the conventional C-arm group (2.7778% VS 28.5724%, P = 0.0030*). The intraoperative bleeding in the robot group was lower than that in the conventional C-arm group (320.85 ± 276.28 VS 490.00 ± 395.34, P = 0.0420*). The postoperative hospital stay of the robot group was shorter than that of the conventional C-arm group (10.00 ± 9.32 VS 14.49 ± 7.55, P = 0.0300*). The screw placement inaccuracy score of the robot group was lower than that of the conventional C-arm group (0.17 ± 0.51 VS 1.45 ± 1.46, P = 0.0000*). Conclusion: The combination of the concept of accelerated rehabilitation and Tianji Orthopedic robot-assisted surgery is more effective and safer in posterior lumbar decompression and internal fixation surgery with a screw rod system, and is worthy of promotion and application.

Is Dynesys dynamic stabilization system superior to posterior lumbar fusion in the treatment of lumbar degenerative diseases?

Dynesys,a pedicle-based dynamic stabilization system,was introduced to overcome some undesirable complications of fusion procedures.Nevertheless,the theoretical advantages of Dynesys over fusion have not been clearly confirmed.The purpose of this editorial was to compare clinical and radiological outcomes of patients who underwent Dynesys system with those who underwent posterior lumbar fusion according to the existing literature and to see if the application of the Dynesys system is superior to the traditional lumbar fusion surgery.According to published clinical reports,the short-term effects of the Dynesys dynamic stabilization system are similar to that of traditional lumbar fusion surgery.Three comparative studies of Dynesys dynamic stabilization and fusion surgery with medium-term follow-up are encouraging.However,the results from four single-treatment-arm and small-sample studies of case series with long-term follow-up were not encouraging.In the present circumstances,it is not possible to conclude that the Dynesys dynamic stabilization system is superior to fusion surgery for lumbar degenerative diseases.

Cortical bone trajectory screws in the treatment of lumbar degenerative disc disease in patients with osteoporosis

Lumbar degenerative disc disease(DDD)in the elderly population remains a global health problem,especially in patients with osteoporosis.Osteoporosis in the elderly can cause failure of internal fixation.Cortical bone trajectory(CBT)is an effective,safe and minimally invasive technique for the treatment of lumbar DDD in patients with osteoporosis.In this review,we analyzed the anatomy,biomechanics,and advantages of the CBT technique in lumbar DDD and revision surgery.Additionally,the clinical trials and case reports,indications,advancements and limitations of this technique were further discussed and reviewed.Finally,we concluded that the CBT technique can be a practical,effective and safe alternative to traditional pedicle screw fixation,especially in DDD patients with osteoporosis.

Cortical bone trajectory fixation in cemented vertebrae in lumbar degenerative disease:A case report

BACKGROUND Percutaneous vertebroplasty(PVP)has been widely used in osteoporotic vertebral compression fracture(OVCF).Following surgery,the bone cement would be positioned permanently.However,in some cases of lumbar degenerative disease,the cemented vertebrae needs to be fixed after decompression and fusion procedure.It is difficult to implant traditional pedicle screws into the cemented vertebrae because of the bone cement filling.At present,the main treatment strategy is to skip the cemented vertebra and conduct a long segment fixation.This article presents a cortical bone trajectory(CBT)fixation technique for cemented vertebrae.CASE SUMMARY PVP involving the L3 and L4 was performed in an 82-year-old man due to OVCF.During the surgery,bone cement leakage occurred,resulting in compression of the root of the right L3 nerve.We performed a partial facetectomy to retrieve the leaked bone cement and to relieve the patient’s neurological symptoms.After 3 mo,the patient developed lumbar disc herniation in L3/4,potentially due to instability caused by the previous surgery.Therefore,it was necessary to perform intervertebral fusion and fixation.It was difficult to implant traditional trajectory pedicle screws in L3 and L4 because of the bone cement filling.Hence,we implanted CBT screws in the L3 and L4 vertebrae.As a result,the patient’s symptoms resolved and he reported satisfaction with the surgery at follow-up after 8 mo.CONCLUSION It is feasible to utilize CBT in cemented vertebrae for the treatment of lumbar degenerative disease.

Unilateral pedicle screw fixation combined with lumbar interbody fusion for the treatment of lumbar degenerative diseases

Objective To explore the feasibility and efficiency of the treatment of lumbar degenerative diseases after transforaminal lumbar interbody fusion (TLIF) and posterolateral fusion (PLF) procedures in which unilateral pedicle screw fixation was used.

Potential contribution of pedicle screw design to loosening rate in patients with degenerative diseases of the lumbar spine:An observational study

BACKGROUND The majority of published data report the results of biomechanical tests of various design pedicle screw performance.The clinical relevance and relative contribution of screw design to instrumentation stability have been insufficiently studied.AIM To estimate the contribution of screw design to rate of pedicle screw loosening in patients with degenerative diseases of the lumbar spine.METHODS This study is a prospective evaluation of 175 patients with degenerative diseases and instability of the lumbar spine segments.Participants underwent spinal instrumentation employing pedicle screws with posterior only or transforaminal interbody fusion.Follow-up was for 18 mo.Patients with signs of pedicle screw loosening on computed tomography were registered;logistic regression analysis was used to identify the factors that influenced the rate of loosening.RESULTS Parameters included in the analysis were screw geometry,type of thread,external and internal screw diameter and helical pitch,bone density in Hounsfield units,number of levels fused,instrumentation without anterior support,laminectomy,and unilateral and bilateral total facet joint resection.The rate of screw loosening decreased with the increment in outer diameter,decrease in core diameter and helical pitch.The rate of screw loosening correlated positively with the number of fused levels and decreasing bone density.Bilateral facet joint removal significantly favored pedicle screw loosening.The influence of other factors was insignificant.CONCLUSION Screw parameters had a significant impact on the loosening rate along with bone quality characteristics,the number of levels fused and the extensiveness of decompression.The significance of the influence of screw parameters was comparable to those of patient-and surgery-related factors.Pedicle screw loosening was influenced by helical pitch,inner and outer diameter,but screw geometry and thread type were insignificant factors.

The Incidence and Association of Mental Depression with Symptomatic Lumbar Degenerative Disc Disease and Treatment Outcome

Study Design: Prospective analytical study. Objectives: The aim was to determine the association between mental depression and symptomatic Lumbar Degenerative Disc Disease (LDDD) in patients with no previous background of mental disorder. We also aimed at determining the incidence of mental depressions in patients with LDDD and the effects of the treatment on the mental depression. Methodology: One hundred and sixty patients with no prior history of mental or behavioral disorders who presented with low back pains arising from LDDD and met inclusion criteria were studied. The clinical findings and Depression Screening Test pro-forma were completed for each. The extracted information was analyzed using Statistical Package for Social Science (SPSS) version 24.0. The statistical significance was set at P Results: One hundred and fifty-three patients completed the study, with a male to female ratio of 1:1.5 and the mean age of the patients was 48.5 years. The marital status was 4.4% single, 86.9% married, 3.8% divorce/separate and 5% widow/widower. Their levels of education were: no formal education (10.00%), primary school level (8.10%), secondary level (27.50%) and Tertiary level (54.40%). Conclusions: This study showed the incidence of mental depression in 32% of the patients with LDDD. We also noted a statistically significant relationship between symptomatic LDDD and level of mental depression with significant improvement in the level of depression at 6th month after treatment. Hence, assessment of the patients’ mental health is important in the management of LDDD.

Imaging of Degenerative Pathologies of the Lumbar Spine: Professional Habits in Some Hospitals in Cameroon

Background: The lumbar spine is the portion most frequently involved in degenerative pathologies. Everyone will suffer one day from “low back pain”. These pathologies are very frequent: epidemiological studies have shown that 65% to 90% of the general population could be affected by low back pain (lumbago) which could become chronic at acertain stage or could be complicated (2% to 4%) of cases could end up affecting nerve roots. Chronic low back pain causes a major public health problem in terms of morbidity and socioeconomic repercussions. Purpose: The overall purpose of this study is to evaluate the professional habits of exam applicants in case of degenerative pathologies of the lumbar spine, to Appreciate the knowledge of clinicians on the usefulness of medical imaging techniques in the event of suspicion of a degenerative pathology of the lumbar spine and finally to evaluate if the professional habits of requesting examinations in Cameroon comply with the Recommendations for Clinical Practice. Methods: A cross-sectional and descriptive study was used and was based on questionnaires distributed to those practitioners who requested for these diagnostic medical imaging studies and procedures at Yaoundé General Hospital (HGY), Yaoundé Central Hospital, La Cathédrale Medical Center, Yaoundé University Teaching Hospital, the Douala General Hospital, the Laquintinie Hospital of Douala, the Military Hospital of Douala, the Daniel Muna Memorial Clinic of Douala, the International Center for Clinical and Medicine Imaging, the Ngaoundere Regional Hospital and the Protestant Hospital of Ngaoundere (HPN), from April 2020 to March 2021. Data collected was processed and analyzed via Epi Info version 12.0 and the statistical test used for correlation was Chi2. Results: 137 practitioners were retained among whom, 90 were male and 47 females, their average age being 46 years with working experience less than 5 years (35.8%). The results obtained show that parameters such as availability and accessibility of the required diagnostic medical imaging modalities could greatly influence the examination prescription. On the contrary, few prescribers were less interested in the costs and secondary effects due to irradiation and the invasiveness of these examinations. Professional habits of those who requested these examinations were in majority closer in line with the recommended clinical practices. However, an average of 43.78% of prescribers never followed recommendations nor applied them. On the other hand, knowledge and the application of these recommendations increased as the prescriber’s working experience too increased. Up to 54.47% of prescribers were not aware of those recommendations about requesting these examinations. Conclusion: Our results indicate that Medical Diagnostic Imaging techniques are not judiciously and optimally exploited in the diagnosis of degenerative pathologies of the lumbar spine and it would be necessary to establish recommendations for clinical practice adapted to Cameroonian realities.

Manipulation for degenerative lumbar spondylolisthesis:A systematic review of randomized controlled trials

Objective: To assess the effectiveness and safety of manipulation intervention for degenerative lumbar spondylolisthesis(DLS).Methods: This is a systematic review and meta-analysis. A full-scale retrieval method was performed until February 1, 2021, including nine databases. The homogeneity of different studies was summarized using the Review Manager. The quality of studies was determined with the Cochrane risk-of-bias tool.The evidence quality was graded with the Grading of Recommendations, Assessment, Development, and Evaluations approach.Results: A total of 6 studies involving 524 participants were included. The review demonstrated that manipulation has statistically significant improvements for treating DLS according to Japanese Orthopedic Association scores(mean difference, 3.76;95% confidence interval, 2.63 to 4.90;P <.001) and visual analog scale scores(mean difference,-1.50;95% confidence interval,-1.66 to-1.33;P <.001)compared to the control group. One study reported that the difference in the Oswestry Disability Index between the traction group and the combination of manipulation and traction group was statistically significant(P <.05), while another reported that manipulation treatment can significantly improve the lumbar spine rotation angle on X-ray images compared with the baseline data(P <.05). Moreover, the manipulation group(experimental group) had fewer adverse events than the lumbar traction group(control group).Conclusion: Manipulation intervention is more effective and safer for DLS. Nevertheless, large-scale randomized controlled trials are required to confirm the current conclusions.

Application of Finite Element Analysis in Biomechanical Research of Degenerative Diseases of Lumbar Spine

As the elderly population continues to grow, the number of patients with low back pain is gradually increasing. Among them, Lumbar Degenerative Diseases (LDD) is one of the major contributors to low back pain. Biomechanical in vivo studies of the lumbar spine are mainly performed by implants or imaging data to record the real-time changes of form and stress on the intervertebral disc during motion. However, the current developments are slow due to the technological and ethical limitations. In vitro experiments include animal experiments and cadaver experiments, which are difficult to operate or differ greatly from normal human structures, and the results still need to be verified repeatedly to test their accuracy. As for finite element method, it is relatively low cost and can repeat the experimental results. Therefore, we believe that finite element analysis plays an extremely important role in biomechanical research, especially in analyzing the relationship between different surgical models and the degeneration caused by different mechanics.

Hot Spots and Frontiers of Research on Degenerative Lumbar Spondylolisthesis in China-Visualization Analysis Based on Citespace

Objective:Through the presentation and visual analysis of the Citespace knowledge map,the future research hotspots and trends of domestic research on degenerative lumbar spondylolisthesis are predicted.Methods:By searching the relevant literature on"degenerative lumbar spondylolisthesis"included in the CNKI database from the establishment of the database to January 1,2021,the annual publication volume,fund projects,research authors,research institutions,and research of the included literature For hotspots and other aspects,visual analysis was carried out with the help of Citespace software.Results:(1)A total of 266 related documents were included,of which 27 were published at the end of 2020;(2)The most funded projects are the National Natural Science Foundation of China(9 projects)and the National Science and Technology Support Program(5 projects);(3)In terms of author analysis,Zhu Liguo(16 articles),Yu Jie(13 articles),and Gao Chunyu(8 articles)rank the top three in terms of author analysis;(4)In terms of research institutions,Wangjing Hospital of China Academy of Chinese Medical Sciences(17 articles),Henan University of Chinese Medicine(4 articles),and Nanjing University of Chinese Medicine(4 articles)were the top 3 research institutions in terms of publication volume;(5)The keyword clustering label was"degenerative lumbar spondylolisthesis","lumbar spine","lumbar spondylolisthesis","degenerative lumbar spondylolisthesis","clinical observation"and"tuina".Conclusion:Research on"degenerative lumbar spondylolisthesis"has gradually received widespread attention,but the amount of publications is still relatively small;relevant domestic researchers and research institutions have formed a certain degree of influence across the country,but large-scale national cooperation research is still scarce,and strengthening academic exchanges and cooperation is still an important direction for researchers and research institutions in this field in the future.The research direction of lumbar spinal stenosis caused by degenerative lumbar spondylolisthesis will be a new direction and entry point for the study of degenerative lumbar spondylolisthesis in recent years.

Central plasticity resulting from chronic low back pain in degenerative disorders of the spine

Degenerative disorders of the spine are the most common cause of chronic low back pain（c LBP）;in Western Europe alone,billions of euros are spent each year on both conservative and surgical treatments for c LBP.And though only 5%of all patients with low back pain suffer from lumbar disc herniation（LDH）,

Surgical treatment of degenerative scoliosis

Objective To investigate the techniques of posterior lumbar interbody fusion and pedicle screws in the treatment of degenerative scoliosis and evaluate their clinical significance. Methods Twenty five patients with degenerative scoliosis were treated operatively during 1997 -2002. Among the 25 pateints,13 pateints were treated with Brantigan I/F carbon cages in 28 intervertebral spaces,7 patients were treated with Prospace cages in 15 spaces, 1 patient was treated with CONTACT cages in 2 spaces. The correcting effects, complications and follow-up results were analyzed retrospectively. Results The average correction rate of scoliosis was 59 % and the rate of pain relief was 88 %. There were a case of pseudoarthritis and a case of embolism. During follow-up, correction rate and height of dics spaces were not lost nor shift of interbody cages. Conclusion Posterior pedicle screws combined with interbody fusion is a safe and effective treatment for degenerative scoliosis. 5 refs, 2 figs.

Factors that influence the results of indirect decompression employing oblique lumbar interbody fusion

BACKGROUND Indirect decompression is one of the potential benefits of anterior reconstruction in patients with spinal stenosis.On the other hand,the reported rate of revision surgery after indirect decompression highlights the necessity of working out prediction models for the radiographic results of indirect decompression with assessing their clinical relevance.AIM To assess factors that influence radiographic and clinical results of the indirect decompression in patients with stenosis of the lumbar spine.METHODS This study is a single-center cross-sectional evaluation of 80 consecutive patients(17 males and 63 females)with lumbar spinal stenosis combined with the instability of the lumbar spinal segment.Patients underwent single level or bisegmental spinal instrumentation employing oblique lumbar interbody fusion(OLIF)with percutaneous pedicle screw fixation.Radiographic results of the indirect decompression were assessed using computerized tomography,while MacNab scale was used to assess clinical results.RESULTS After indirect decompression employing anterior reconstruction using OLIF,the statistically significant increase in the disc space height,vertebral canal square,right and left lateral canal depth were detected(Р<0.0001).The median(M)relative vertebral canal square increase came toМ=24.5%with 25%-75%quartile border(16.3%;33.3%)if indirect decompression was achieved by restoration of the segment height.In patients with the reduction of the upper vertebrae slip,the median of the relative increase in vertebral canal square accounted for 49.5%with 25%-75%quartile border(2.35;99.75).Six out of 80 patients(7.5%)presented with unsatisfactory results because of residual nerve root compression.The critical values for lateral recess depth and vertebral canal square that were associated with indirect decompression failure were 3 mm and 80 mm2 respectively.CONCLUSION Indirect decompression employing anterior reconstruction is achieved by the increase in disc height along the posterior boarder and reduction of the slipped vertebrae in patients with degenerative spondylolisthesis.Vertebral canal square below 80 mm2 and lateral recess depth less than 3 mm are associated with indirect decompression failures that require direct microsurgical decompression.

Dynesys dynamic stabilization system for the lumbar degenerative disease： a preliminary report from China

Background Dynesys dynamic stabilization system in 2007. Therefore, it was a new technique for Ch about Dynesys in China. The objective of this study degenerative disease in China. was first implanted in patients in 1994, and introduced to China nese orthopedics and hence necessary to collect clinical data was to report the preliminary results of Dynesys for the lumbar Methods Twenty-seven patients were treated with the Dynesys between July 2007 and January 2009. The diagnosis included degenerative spondylolisthesis （12 cases）, degenerative spinal stenosis （nine cases）, and lumbar intervertebral disc herniation （six cases）. Back pain and leg pain were evaluated using 100-mm visual analog scales （VAS）. The Oswestry Disability Index （ODI） was used to evaluate the patients＇ function. The intervertebral disc height and range of motion at the operative level were taken on radiographs. Results All the patients were followed-up, with an average of （22.40±4.23） months （range 15±32 months）. VAS of back pain and leg pain were improved significantly （P 〈0.05） at foUow-up. The ODI scores were reduced from （62.58±12.01）% preoperatively to （15.01±5.71）% at follow-up （P 〈0.05）. The preoperative mean height of the intervertebral disc was （11.21±1.58） mm （range 8.5±13.8 mm） and mean was （10.10±1.78） mm （range 7.0±13.4 mm） at follow-up （P 〈0.05）. The mean range of motion of the implanted segment was （6.00±1.79）° （range 2.5-9.3°） preoperatively and （5.47±1.27）° （range 2.9±7.8°） at follow-up （P=0.11）. Conclusions The preliminary results of Dynesys for the lumbar degenerative disease in China are similar to the published results of other countries. It can significantly improve the clinic symptoms and preserved motion at the level of implantation. However, the long-term follow-up data need to be collected.

Minimum 5-year follow-up study on the effects of the Wallis dynamic stabilization system in the treatment of lumbar degenerative disease

Background Short-term outcomes of the Wallis system in the treatment of lumbar degenerative disease （LDD） have been shown to be effective, whereas there is a paucity of studies on the mid-long-term effects of the treatment of the Wailis system. This study was to evaluate the mid-long-term effects of the Wallis dynamic stabilization system in the treatment of LDD. Methods A total of 26 patients who received the treatment of the Wallis system between February 2008 and January 2009 were included in the study, with 14 patients （Group 1） with L4/5 disc herniation and 12 patients （Group 2） with L5/S1 disc herniation and L4/5 intervertebral disc degeneration （IDD）. Visual analog scale （VAS） and Oswestry Disability Index （ODI） were used to evaluate the clinical outcomes and lumbar X-rays and MRI were obtained to observe imaging changes before and after operation. Results The mean follow-up period was （63.50＋2.12） months. The mean ODI and VAS scores decreased obviously three months and five years after operation （P 〈0.05）. In Groups 1 and 2, L4/5 Cobb angle and range of motion （ROM） decreased and L4/5 posterior disc height increased at the last follow-up （P 〈0.05）. There were no statistically significant changes in L4/5 anterior disc height and L3/4 University of California at Los Angeles grading before and after operation. There was no statistically significant change in Pfirrmann grading system of L4/5 IDD in Group 2 before and after operation. Adjacent segment degeneration at the last follow-up was found in two patients （2/26, 7.69%） and Modic changes in L4/5 endplates were detected in one patient （1/26, 3.85%）. Conclusions The mid-long-term effects of the Wallis system in the treatment of LDD were satisfied. The Wallis system, as a dynamic stabilization system, which can preserve some ROM of the fixed segment, sustain the lumbar stabilization, and prevent adjacent segment disease and fixed segment degeneration, is an effective instrument to treat LDD.

Preliminary evaluation of posterior dynamic lumbar stabilization in lumbar degenerative disease in Chinese patients

Background There has been some controversy related to the use of the Wallis system,rather than disc fusion in the treatment of patients with degenerative spine disease.Furthermore,there are no reports concerning the application of this dynamic stabilization system in Chinese patients,who have a slightly different lifestyle with Western patients.The aim of this study was to assess the safety and efficacy of the dynamic stabilization system in the treatment of degenerative spinal diseases in Chinese patients.Methods The clinical outcomes of 20 patients with lumbar degenerative disease treated by posterior decompression with the Wallis posterior dynamic lumbar stabilization implant were studied.All of the patients completed the visual analogue scale and the Chinese version of the Oswestry Disability Index.The following radiologic parameters were measured in all patients：global lordotic angles and segmental lordotic angles （stabilized segments,above and below adjacent segments）.The range of motion was then calculated.Results Nineteen patients （95%） were available for follow-up.The mean follow-up period was （27.25±5.16） months （range 16-35 months）.The visual analogue scale decreased from 8.55±1.21 to 2.20±1.70 （P 〈0.001）,and the mean score on the Chinese version of the Oswestry Disability Index was improved from 79.58%±15.93% to 22.17%±17.24% （P 〈0.001）.No significant changes were seen in the range of motion at the stabilized segments （P=0.502） and adjacent segments （above,P=0.453; below,P=0.062）.The good to excellent result was 94.4% at the latest follow-up.No complications related to the use of the Wallis posterior dynamic lumbar stabilization occurred.Conclusions It was found to be both easy and safe to use the Wallis posterior dynamic lumbar stabilization implant in the treatment of degenerative lumbar disease,and the early therapeutic effectiveness is good.The Wallis system provides an alternative method for the treatment of lumbar degenerative disease.

A comparison of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion for lumbar degenerative diseases

Background Bilateral transpedicular screw fixation in conjunction with interbody fusion is widely used to treat lumbar degenerative diseases; however, there are some disadvantages of using this fixation system. This study comparatively analyzes the results of unilateral and bilateral pedicle screw fixation combined with transforaminal lumbar interbody fusion （TLIF） for one-level lumbar degenerative diseases. Methods Sixty-six cases with one-level lumbar degenerative diseases were studied. The patients were divided according to surgical approach into a unilateral group （Group A） and a bilateral group （Group B）. The patients were evaluated for pain by visual analog scale （VAS） and Oswestry Disability Index （ODI）. Operating time, blood loss, duration of hospitalization, and complication rate were also evaluated. Patients were examined at 1, 3, 6, and 12 months postoperatively and every year thereafter. Results Group A patients＇ average preoperative VAS and ODI scores were 7.03 ±0.98 and （64.22±6.38）%, respectively, significantly decreased to 2.91 ± 0.88 and （14.42＋2.08）%, respectively, at the last follow-up （P = 0.000）. In Group B, the average preoperative VAS and ODI scores were 6.79±0.86 and （63.22±4.70）%, respectively, significantly decreased to 3.12±0.96 and （14.62±2.08）%, respectively, at the last follow-up （P=-0.000）. No significant difference in the duration of hospitalization was found between groups. Operating time and blood loss of （125.9±13.0） minutes and （211.4±28.3） ml, respectively, in Group A were significantly less than （165.2±15.3） minutes and （258.6±18.3） ml, respectively, in Group B （P=0.000）. All patients achieved good bone union and had no pseudarthrosis at the last follow-up. Conclusions There are no clinical differences between unilateral and bilateral pedicle screw fixation combined with TLIF for one-level lumbar degenerative diseases. Unilateral fixation reduces operating time, bleeding, and cost of hospitalization.

Radiological Analysis of Thoracolumbar Junctional Degenerative Kyphosis in Patients with Lumbar Degenerative Kyphosis

Background： Thoracolumbar junction （TLJ） is the transitional area between the lower thoracic spine and the upper lumbar spine. Vertebral compression fractures and proximal junctional kyphosis following spine surgery often occur in this area. Therefore, the study of development and mechanisms of thoracolumbar junctional degeneration is important for planning surgical management. This study aimed to review radiological parameters of thoracolumbar junctional degenerative kyphosis （TLJDK） in patients with lumbar degenerative kyphosis and to analyze compensatory mechanisms of sagittal balance. Methods： From January 2016 to March 2017, patients with lumbar degenerative kyphosis were enrolled in this radiographic study. Patients were divided into two groups according to thoracolumbar junctional angle （TLJA）： the non-TLJDK （NTLJDK） group （TLJA 〈10°） and the TLJDK group （TLJA≥10°）. Complete spinopelvic radiographic parameters were analyzed and compared between two groups. Pearson or Spearman correlation coefficients and independent two-sample t-test or Mann-Whitney U-test were used. Results： Atotal of 77 patients with symptomatic sagittal imbalance due to lumbar degenerative kyphosis were enrolled in this study. There were 34 patients in NTLJDK group （TLJA 〈10°） and 43 patients in TLJDK group （TLJA ≥10°）. The median angle of lumbar lordosis （LL） in the NTLJDK or TLJDK groups was 23.40° （18.50°, 29.48°） or 19.50° （13.30°, 24.55°）, respectively. The median TLJAs in all patients and both groups were -11.20° （-14.60°, -4.80°）, -3.70° （-7.53°, -1.73°）, and -14.30° （-17.45°, -13.00°）, respectively. In the NTLJDK group, LLwas correlated with thoracic kyphosis （TK; r = -0.400, P = 0.019）, sacral slope （SS; r = 0.681, P 〈 0.001）, and C7-sagittal vertical axis （r = -0.402, P = 0.018）. In the TLJDK group, LL was correlated with TK （r = -0.345, P = 0.024）, SS （r = 0.595, P 〈 0.001）, and pelvic tilt （r = -0.363, P = 0.017）. There were significant differences in LL, TLJA, TK, SS, and pelvic incidence （PI） between two groups. Conclusions：Although TLJDK is common in patients with lumbar degenerative kyphosis, it might be generated by special characteristics of morphology and biomechanics of the TLJ. To maintain sagittal balance, pelvis back tilt might be more important in patients with TLJDK, whereas thoracic curve changes might be more important in patients without TLJDK.

Mineralized collagen-modified PMMA cement enhances bone integration and reduces fibrous encapsulation in the treatment of lumbar degenerative disc disease

As a minimally invasive surgery,percutaneous cement discoplasty(PCD)is now contemplated to treat lumbar disc degeneration disease in elder population.Here,we investigated whether the osteogenic mineralized collagen(MC)modified polymethylmethacrylate(PMMA)cement could be a suitable material in PCD surgery.Injectability,hydrophilicity and mechanical properties of the MC-modified PMMA(PMMA-MC)was characterized.The introduction of MC did not change the application and setting time of PMMA and was easy to be handled in minimally invasive operation.Hydrophilicity of PMMA-MC was greatly improved and its elastic modulus was tailored to complement mechanical performance of bone under dynamic stress.Then,PCD surgery in a goat model with induced disc degeneration was performed with implantation of PMMA-MC or PMMA.Three months after implantation,micro-computed tomography analysis revealed a 36.4%higher circumferential contact index between PMMA-MC and bone,as compared to PMMA alone.Histological staining confirmed that the surface of PMMA-MC was in direct contact with new bone,while the PMMA was covered by fibrous tissue.The observed gathering of macrophages around the implant was suspected to be the cause of fibrous encapsulation.Therefore,the interactions of PMMA and PMMA-MC with macrophages were investigated in vitro.We discovered that the addition of MC could hinder the proliferation and fusion of the macrophages.Moreover,expressions of fibroblaststimulating growth factors,insulin-like growth factor,basic fibroblast growth factor and tumor necrosis factor-b were significantly down-regulated in the macrophages cocultured with PMMA-MC.Together,the promoted osteointegration and reduced fibrous tissue formation observed with PMMA-MC material makes it a promising candidate for PCD surgery.