Construction of Spine Biomechanical Test System Based on LabVIEW and Six-Axis Robot Arm and Preliminary Reliability Study / 医用生物力学

Objective To construct a new biomechanical testing system of in vitro spine based on LabVIEW and six-axis robot arm and conduct preliminary reliability studies, so as to make preparation for further studies on coupled motion testing. Methods By programming on LabVIEW platform, using Ethernet and Profibus to communicate the data of the robot arm with PC in real time, the displacement control and load control were realized, and the end position and rotation angle of the robot arm were read in real time. Through the force/torque sensor and data acquisition (DAQ), board DAQ, processing, storage and other functions were acquired. Using the digital micrometer and special stationary fixture, the 6-direction translation accuracy test was completed, and the data were analyzed. The flexion, extension, lateral flexion and rotation were applied on sheep spine specimen to draw the load-displacement curve, analyze and compare the experimental result, and verify the effectiveness of the biomechanical platform. Results A biomechanical test system with high precision for spine in vitro based on LabVIEW and 6-axis robot arm was developed and established, of which the average translational precision was 8.1 μm and the average translational accuracy was 56.7 μm. The program of control, data acquisition, data processing and storage were written, and the biomechanical test of the sheep spine was completed effectively. Conclusions This biomechanical test system based on Labview and 6-axis robot arm could complete the conventional three-dimensional spinal motion test with high precision and be used to conduct coupled motion test research in the next step.

Advances in Application of Spine Follower Loads in Biomechanical Studies in vitro / 医用生物力学

The importance of follower loads in maintaining spine biomechanics was described, and the various methods and means of follower load simulations of human spine specimens in vitro in recent years were summarized. By comparison with the real data of range of motion (ROM) and intervertebral disc pressure of human vertebral body, the feasibility of various simulation methods was analyzed from the perspectives of mechanics, and the optimal loading load and torque of human cervical, thoracic and lumbar vertebrae biomechanical experiments were summarized. The effects of conventional spinal internal fixation on biomechanical properties of the spine were also discussed.

Advances in Loading Methods of in vitro Spinal Biomechanical Test / 医用生物力学

The description for load-displacement characteristics of in vitro spinal specimens in three-dimensional (3D) motion is the foundation of spinal biomechanical research. How to simulate the load and movement of spine in vivo as accurately as possible is the difficulty of in vitro spinal biomechanical research. Domestic and foreign scholars have carried out extensive research on theories and equipments of spinal biomechanical test. Currently, the spinal 3D motion test is mainly divided into load control, displacement control and hybrid control according to the control method. Based on different control method, the test equipments are also developing and perfecting constantly. The operation principle for current in vitro spinal loading devices are summarized, and their advantages and disadvantages are also analyzed, so as to provide references for the research on in vitro spinal biomechanical loading devices.

Experimental study on the effect of sleeve type guide growth rod on spinal growth of piglet / 中华骨科杂志

Objective To evaluate the efficacy of the sleeve type guide growth rod sliding automatically with the growth of piglet spine.Methods Fourteen 4-month-old piglets were randomly divided into growth rod group (n=8) and control group (n=6).Animals in growth rod group were implanted with the sleeve type guide growth rod system through the small incision of the tho racodorsal.Whereas ones in control group were just expose the bilateral lamina.On the day of surgery,6 and 12 weeks of postoperation,all piglets accepted the spinal X-ray examination.Measured the mean height of T8,T9 vertebral bodies,the average height of T7-8,T8-9,Tg-10 discs and the mean length of the rods through X-ray film.Spinal MRI was measured 3 months after the operation.The morphological changes of the plate were observed after HE staining.The morphological changes of the nucleus pulposus cells were observed and the thickness of the growth plate and the length of the growth bar were measured.Results Two piglets of growth rod group did not complete the experiment,1 piglet died of aspiration due to anesthesia resuscitation,and 1 piglet had infection after operation.The average height of T8,T9 vertebral bodies of the piglets in the growth rod group on the day after surgery and 3 months after operation was 18.26±3.26 mm and 27.15±4.18 mm,respectively,and the difference was statistically significant (F=16.868,P=0.002).Similarly,the mean height of T7-8,T8-9,Tg-10 discs of the piglets in growth rod group on the day after surgery and 3 months of postoperation was 1.79±0.24 mm and 2.14±0.23 mm,respectively,and the difference was statistically significant (F=6.455,P=0.029).The average height of T8,T9 vertebral bodies in the control group on the day after surgery and 3 months after operation was 17.86±3.50 mm and 28.63±4.45 mm,respectively,and the difference was statistically significant (F=21.654,P=0.001).Similarly,the mean height of T7-8,Ts-9,Tg-10 discs in control group at the day after surgery and 3 months of postoperation was 1.78±0.27 mm and 2.17±0.30 mm,respectively,the difference was statistically significant (F=5.928,P=0.035).There was no statistically significant difference in average height between T8 and T9 vertebral bodies in growth rod group and the control group at 3 months after operation (F=0.352,P=0.566).Similarly,There was no statistically significant difference in average height of T7-8、Ts-9、Tg-10 discs in growth rod group and the control group at 3 months after operation (F=0.053,P=0.823).The average sliding length of the growth rod in growth rod was 65.74 mm.Furthermore,growth plate chondrocytes and nucleus pulposus cells in EG and SG,all showed that the cells were arranged in order,the cell volume was large,the shape was round and the cytoplasm was rich.Simultaneously,there was no significant difference between the two groups in growth plate chondrocytes (P ＞ 0.05).Conclusion The sleeve type guiding growing rod can automatically slip to extend due to the driving force of young pig's spine growth,without obvious effects on the normal growth of piglet's spine.

MicroRNAs: a type of novel regulative factor for intervertebral disc degeneration / 浙江大学学报·医学版

Intervertebral disc degeneration (IDD) is one of major causes for intervertebral disc degenerative diseases, and patients with IDD usually suffer from serious low back pain. The current treatments for patients with IDD only relieve the clinical symptom rather than restore biological balance of IDD, leading to inadequate and unsatisfactory results. MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded RNA molecules, which regulate the gene expression at the post-transcription levels. Research evidences support the involvement of miRNAs in many biological processes, such as lipid metabolism, apoptosis, differentiation and organ development. Accumulating evidences indicate that the expressions of miRNAs change significantly in degenerative tissues. In addition, dysregulated miRNAs contribute to multiple pathological process of IDD, including proliferation and apoptosis of nucleus pulposus and extracellular matrix components, inflammatory response and cartilage endplates degeneration. In this review article, we summarize the expression profiles and roles of miRNAs in IDD, which may provide a novel strategy of biological therapy for the disease.

Clinical application of flipping periosteum pedicle occipital outer plate for atlantoaxial fusion / 中华骨科杂志

Objective To evaluate the feasibility and efficacy of atlantoaxial fusion by flipping periosteum pedicle occipital outer plate.Methods Between March 2010 and June 2013,27 patients with atlantoaxial instability were treated by atlantoaxial fusion with flipping periosteum pedicle occipital outer plate and combining pedicle screws fixation.There were 16 males and 11 females with the age ranging from 23 to 56 years (with an average of 45.6 years) at time of surgery.There were 12 cases of fresh odontoid fracture with atlantoaxial instability,7 cases of old odontoid fracture combined with uneducable atlantoaxial dislocation,7 cases of congenital loose of odontoid process,and 1 case of rheumatoid arthritis.The visual analog scale (VAS) scores and Frankel grades were respectively used to evaluate the axial neck pain and the neurological deficit,and the results were compared before and after the operation.Bony fusion was observed by the midline sagittal CT scan images.Results All the patients were successfully operated.The operation time was 90 to 140 mins (with an average of 100 mins),and the blood loss was 100 to 600 ml (with an average of 160 ml).All patients were followed up for 18 to 39 months,with an average of 32.6 months.19 cases got solid fusion 3 months after surgery,and 7 cases got solid fusion 6 months after surgery,while 1 case got solid fusion 9 months after surgery.The average VAS score at final follow-up was 2.87± 1.03,which was significantly lower than that preoperatively 7.23± 1.65.Before the operation,nine cases presented spinal nerve function damage.At the final follow up time,7 cases returned to complete normal and 2 cases improved from grade C to grade D according to the Frankel classification.1 case was complicated with veiniplex injury with no heavy blood loss,due to successful hemostasia.Two screws were placed close to the vertebral artery canal,without clinical consequences.Conclusion The flipping periosteum pedicle occipital outer plate as a bone graft is one effective method for atlantoaxial fusion,which got great feasibility and safety.

Fusion and non-fusion fixation for cervical spondylotic myelopathy:which is more appropriate for maintaining range-of-motion and stability of vertebrae? / 中国组织工程研究

BACKGROUND:In recent years, many scholars adopted a joint non-fusion and fusion spinal fixation for multisegmental cervical spondylotic myelopathy, and achieved good clinical results. However, long-term clinical efficacy and possible related complications also require long-term fol ow-up of more in-depth study. OBJECTIVE:To review the research and application progress of anterior fusion and non-fusion fixation surgical operation for cervical myelopathy. METHODS:Computer-based search was conducted in China Journal Ful-text Database and PubMed database by the first author for articles related to anterior fusion and non-fusion fixation surgical operation for cervical myelopathy published between January 2004 and January 2014. The key words were“implant material;cervical spondylotic myelopathy;anterior;surgery;fusion;non-fusion;progress;hybrid;summary”in Chinese and“implant material;cervical spondylotic myelopathy;anterior;surgery/operation;fusion;non-fusion;research progress;hybrid;summary”in English. Final y, 35 articles were included for review. RESULTS AND CONCLUSION:Fusion and non-fusion fixation methods for cervical spondylotic myelopathy had their own advantages. From the view point of indications, the non-fusion fixation was relatively limited. Currently, the fusion fixation was stil the main method in treatment of cervical myelopathy. Non-fusion method as an emerging fixation method also achieved good short-period results, but it needs a long fol ow-up study. Hybrid fixation integrates the advantages of both methods, and can reduce the pressure. Simultaneously, Hybrid fixation also can reduce fusion segments, and retain the range-of-motion of the cervical spine as much as possible. Hybrid fixation becomes a hot topic in recent studies. However, most current researches on Hybrid fixation are retrospective study, lack of control. The overal fol ow-up time is short. Thus, Hybrid fixation needs to be researched more deeply.

Clinical application of anterior lumbar interbody fusion assisted with laparoscopic / 中华骨科杂志

ObjectiveTo evaluate the clinical outcomes of anterior lumbar discectomy and interbody fusion with cage under laparoscopic assistant.MethodsFrom January 2006 to June 2009,37 cases with degenerative low back pain were entered the study,including 22 males and 15 females with an average age of 43.7 years(range,16-55).The responsible discs were determined according to the three dimensional computed tomography of artery and vein angiography of anterior lumbosacral spine and discography,including L5S1 in 21 cases,L4-5 in 11,L3-4 in 2,L2-3 in 2,and L1-2 in 1.All cases underwent anterior lumbar discectomy and interbody fusion with cage under laparoscopic.ResultsThe operation time was 100 min in average (range,60-140),the blood loss was 120 ml in average(range,50-300).There was no case with severe complications of retrograde ejaculation and injury of great vessels or nerves.Delayed intestinal obstruction was discovered in two intraperitoneal route patients.The average follow-up time was 18.7 months(range,6-35).According to the back pain grading criteria of Chinese Medical Association Orthopedics Society of Spine Group,the results were excellent in 23 patients,good in 11,and fair in 3.The interbody fusion was obtained in 3 months later in 23 cases and 6 months later in 12 cases.Cage subsidence occurred in 2 cases in 6months after operation,in which the height loss of intervertebral space was 1.3 mm and 1.9 mm,but no obvious symptoms of discomfort.No fixation displacement or loosening occurred.ConclusionThe anterior discectomy and interbody fusion by internal fixation with laparoscopic technique is feasible with low complications rate,less trauma and shorter bedtime.Postoperative ileus by abdominal approach is relatively common.The surgeons experience and the anatomy of artery and vein of anterior lumbosacral spine should be considered before the choice of surgical approach.

Itraoperative wake-up test during surgery for severe ossification of ligamentum flavum / 中华创伤杂志

Objective To assess the efficacy and safety of intraoperative wake-up test during surgery for ossification of the ligamentum flavum(OLF). Methods Between June 2004 and June 2010,35 patients(23 males and 12 females,at age range of 32-71 years,mean 50.5 years) with OLF underwent posterior decompressive laminectomy and excision of OLF.The operation wag performed on the cervical vertebrae in four patients,on the thoracic vertebrae in 24 and on the lumbar spine in seven,with monosegmental OLF in 14 patients and multisegmental OLF in 21.The outcomes were evaluated using Japanese Orthopaedic Association (JOA) scale. Results The operation lasted for mean 190 minutes (120-260 minutes),with the blood loss for mean 350 ml (220-520 ml)and the mean 2.4(1-5) lamin receiving decompression.The follow-up period ranged from 6 to 72 months (mean 29.5 months).The JOA score was improved from 4.302±1.023 preoperatively to 8.327±1.032 at the final follow-up (P<0.01).The neurological symptoms was aggravated during operation in three patients,for whom the muscles force recovered gradually in two patients but one showed no change after special measures.No serious complication was found in the other patients postoperatively. Conclusions The wake-up test can serve as an effective monitoring during the procedure ofthe decompressive laninectomy in the patients with severe OLF and decrease the occurrence of neurologic deficit complications.

Microendoscopic cervical discectomy and intervertebral fusion with carbon fiber reinforced polymer Cage by anterior approach for treatment of cervical spondylosis A 25-case analysis / 中国组织工程研究

BACKGROUND:Techniques of antedor cervical discectomy and interbody fusion have achieved good clinical outcomes since Robinson and Smith first introduced it in 1955.Currently,microendoscopic approaches have resulted in good clinical effectiveness in treating cervical spondylosis.Cage has also been used widely in the clinic.OBJECTIVE:To find a minimally invasive method that uses microendoscopic technique and Cages to treat cervical spondylosis by anterior approach.DESIGN,TIME AND SETTING:A retrospective case analysis was performed at the Department of Spinal Surgery,First Affiliated Hospital of University of South China between January 2003 and July 2008.PARTICIPANTS:A total of 25 patients with cervical spondylosis,15 males and 10 females,averaging 39 years of age (range,33-58 years old),who received treatments at the Department of Spinal Surgery,First Affiliated Hospital of University of South China were included in this study.Each of them had unilateral limb pain,numbness or weakness in varying degrees.MRI image showed one-level cervical disc degeneration in 20 patients and two levels in 5 patients.METHODS:Twenty-five patients underwent anterior cervical microendoscopic discectomy and interbody fusion using carbon fiber reinforced polymer (CFRP) Cage.Surgical techniques,neurological outcomes and complications were retrospectively analyzed.The postoperative treatments were just like the conventional approaches.MAIN OUTCOME MEASURES:Improvements in neurological symptoms were assessed using the Japanese Orthopedic Association (JOA) grading system.Postoperative imaging data including lordosis and fusion condition were examined.RESULTS:All patients received treatments successfully.The mean surgical time was 140 minutes (range,80 to 225 minutes).The hospital stay averaged 7 days (range,6 to 10 days).Patients' neurological statuses improved to varying degrees according to the JOA grading system:7.5 pre-operative (range,4 to 9 points) to 12 post-operative (range,8 to 16 points),with the mean improvement rate of 45.6%.All cases were followed up and the mean follow-up period was 18 months (range,6 to 27 months).Postoperative images showed solid bone fusion without implant migration.No vascular injury and infection occurred.Graft collapse was found in 2 patients,and transient hoarse voice in 1 patient.No other complications were found.CONCLUSION:Anterior microendoscopic cervical discectomy and interbody fusion with CFRP Cage in treatment of cervical spondylosis have the advantages of minimal invasion,sufficient decompression,and satisfactory bone fusion,resulting in a significant relief of patients' preoperative clinical symptoms.

Biomechanical testing of neotype retropharyngeal cervical hook-plate for atlantoaxial instability / 中国矫形外科杂志

[Objective] To analyze the mechanics of neotype retropharyngeal cervical hook-plate(RCHP)for atlantoaxial instability with biomechanical testing.[Methods]Six fresh adult craniocervical specimens(C0～3)used for testing the biomechanical instability were all putted into following five test courses:intact,instability(Type ⅡOdontoid fracture),RCHP,Anterior C1、2 transarticular screw fixation,brooks.Repeated statistical analysis of the data was performed using the SPSS 13.0 software package.Measures were performed with SNK testing method to determine whether significant differences existed,P=0.05.[Results]Biomechanical testing showed that,compared with the controlled group and the injured group,each fixation course significantly decreased ROM in all test modes.In the ROM of flexion,there was no significant difference between RCHP and Brooks(P=0.525),but both of them was higher than anterior C1、2 transarticular screw fixation(P

Treatment of thoracolumbar malignant neoplasms by one stage anterior-posterior approach total spondylectomy and spinal reconstraction / 中国矫形外科杂志

[Objective]To study the curative effect and superiority of one stage anterior-posterior approach total spondylectomy and spinal reconstraction in the treatment of thoracolumbar malignant neoplasms.[Method]Twenty-four thoracolumbar malignant neoplasms patients treated by anterior approach total spondylectomy,spinal reconstractin with titanium mesh cage associated with bone graft or bone cement and posterior approach transpediuclar screw fixation.[Result]The follow-up of postoperation was from 9 to 35 months.All patients achieved relieve of pain after surgery,9 cases with incomplete paraplegia improved by 1.8 grades in average with Frankel neurological classifications,2 cases with dysfunction of urination and defecation were recovered,4 patients decease for metastasis in critical organ,all the patients showed bony fusion at 6~9 months,no internal fixation loosening or breakage case was found,1 case was recrudescent after one year.[Conclusion]Treatment of thoracolnmbar malignant neoplasms by one stage anterior-posterior approach total spondylectomy and spinal reconstraction can remove the neoplasms efficiently,reconstraction the spinal stabilization and improve the quality of life.