Establishment of finite element model of anterior cervical transpedicular system for reconstruction of cervical stability after subtotal resection of two segments of lower cervical spine / 中国骨伤

OBJECTIVE@#To establish the fixation model of anterior cervical transpedicular system (ACTPS) after subtotal resection of two segments of lower cervical spine(C3-C7) in order to provide a finite element modeling method for anterior cervical reconstruction.@*METHODS@#The CT data of the cervical segment (C1-T1) of a 30-year-old adult healthy male volunteer was collected. Used Mimics 10.0, Rapidform XOR3, HyperMesh 10.0, CATIA5V19 and ANSYS 14.0 to establish the three-dimensional nonlinear complete model of lower cervical spine(C3-C7) as the intact group. The number of units and nodes of the complete model were recorded. After the effectiveness of the complete model was verified, the C5 and C6 vertebral subtotal resection was performed, and the ACTPS model was established as the ACTPS group. The axial force of 75 N and moment couple of 1N·m was loaded on the upper surface of C3 in intact group and ACTPS group, the range of motion(ROM)and stress distribution in states of flexion extension, lateral flexion, rotation was compared between two groups.@*RESULTS@#There were 85 832 elements and 23 612 nodes in the complete model of lower cervical spine(C3-C7) which was established in this experiment. The stress distribution of ACTPS internal fixation model was relatively uniform. Comparing with the intact group, the overall range of motion in ACTPS group was decreased in flexion extension, lateral flexion and rotation directions, and the corresponding compensation of adjacent C3,4 segment was increased slightly.@*CONCLUSION@#The stress distribution of ACTPS fixation system is uniform, there is no stress concentration area at the joint of screw and titanium plate, and the fracture risk of internal fixation is low. It is suitable for stability reconstruction after anterior decompression of two or more cervical segments.

Comparative study between 3D guide plate assisted and free-hand insertion of anterior cervical transpedicular screw / 中国骨伤

OBJECTIVE@#To compare accuracy of anterior cervical pedicle screws between assist of rapid prototyping 3D guide plate and free-hand insertion, and evaluate the safety of two methods.@*METHODS@#Eight adult cervical cadaver specimens after formaldehyde immersion, including 4 males and 4 females, aged 32 to 65(40.3±5.6) years old. After X-ray examination to exclude bone damage and deformity, 4 of them (3D guide plate group) randomly selected were for CT scan to obtain DICOM format data, and the data was imported into Mimics software for model, designed the ideal entry point and nail path for anterior cervicaltranspedicular screw (ATPS). After obtaining the personalized guide plate of the nail channel, it was exported as STL data, and the individual guide plate was printed by rapid prototyping and 3D printing technology. In turn, with the assistance of 3D guide plates, one-to-one personalized ATPS screws were placed on the four lower cervical cadaver specimens. Another 4 (free-hand group) lower cervical cadaver specimens were implanted with ATPS screws using free-hand technique. All specimens were performed CT thin-layer scanning and three-dimensional reconstruction after operation. The Tomasino method was used to evaluate the safety of the screws on the CT cross-sectional and sagittal images, to determine whether there was a cortical puncture of the lower and inner edges of the pedicle. According to the CT rating results, gradeⅠandⅡwere safe, and grade Ⅲ- Ⅴ were dangerous.And the accuracy of screws was recorded and analyzed between two groups.@*RESULTS@#Two screws were inserted in each segment from C@*CONCLUSION@#The 3D printing rapid prototyping guide plate assisted insertion of the anterior cervical pedicle screw can significantly improve the accuracy and safety, and provide a theoretical basis for further clinical application.

Short-segment pedicle screw fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis / 中国骨伤

OBJECTIVE@#To explore the clinical effects of posterior short-segment pedicle screw internal fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis.@*METHODS@#Twenty-four patients with Kümmell disease complicated with kyphosis treated by posterior short-segment pedicle screw internal fixation combined with vertebroplasty from January 2016 to December 2018 were retrospectively analyzed, including 6 males and 18 females, aged 63 to 85 (73.1±6.5) years old. The clinical effect was evaluate by visual analogue scale (VAS), Oswestry Disability Index (ODI), the anterior height of injured vertebral body, and the sagittal Cobb angle of the affected segment beforeoperation, at 3 days and final follow up after operation. And the surgical complications were observed.@*RESULTS@#All 24 patients were followed up from 12 to 24 months with an average of (15.5±3.2) months. The VAS score was decreased from 5.21±1.06 preoperatively to 2.38±0.58 at 3 days postoperatively and 1.71±0.75 at final follow-up;ODI was decreased from (50.4±13.5)% preoperatively to (20.9±8.0)% at 3 days postoperatively and (16.7±9.6)% at final follow-up;the anterior height of injured vertebral body was restored from (8.0±4.2) mm before surgery to (18.1±5.0) mm at 3 days after surgery and (16.8±5.1) mm at final follow up;the sagittal Cobb angle of affected segment was decreased from (19.5±6.3)° preoperatively to (7.6±2.1)° at 3 days after surgery and(8.4±1.7)° at final follow-up. VAS, ODI, anterior height of injured vertebral body, and sagittal Cobb angle of affected segment were significantly improved at 3 days after operation and at final follow-up (@*CONCLUSION@#Posterior short-segment pedicle screw internal fixation combined with vertebroplasty for the treatment of Kümmell disease with kyphosis has relatively small surgical trauma, excellent clinical results, good vertebral height recovery, satisfactory correction of kyphotic angle, and fewer complications, etc. It is a safe and effective surgical method to treat Kümmell disease with kyphosis.

Modified Stoppa approach in treatment of bilateral pubic branch fractures / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the feasibility and effectiveness of modified Stoppa approach in treatment of bilateral pubic fractures of pelvic.</p><p><b>METHODS</b>The therapeutic effects of 16 patients with bilateral pubic fractures treated through the modified Stoppa approach from January 2010 to January 2014 were summarized and analyzed, involved 11 males and 5 females with an average age of 40.5 years old ranging from 17 to 59 years. According to Tile classification, there were 8 patients with type A, 6 with type B and 2 with type C. For 16 pelvic fractures, the modified Stoppa approach was used exclusively 11 cases, in combination with the iliac fossa approach in 4 cases, and in combination with the posterior approach in 1 case. The operation incision length, operation time , intra-operative blood loss and postoperative complications were observed. The fracture reduction and post-operative function were assessed by Matta criteria and Majeed system respectively.</p><p><b>RESULTS</b>The incision length of the modified Stoppa approach ranged from 8 to 10 cm (averaged in 9 cm). The operation time ranged from 75 to 135 minutes (averaged in 95 minutes). The intra-operative blood loss ranged from 400 to 900 ml (averaged in 600 ml). Sixteen patients were followed up from 7 to 18 months (averaged in 12.5 months). The fractures were all healed, the fracture healing time was 2.7 to 5 months (means 3.1 months). There were no infections, ectopic ossification, screw loosening, plate breakage and lateral ventral syndrome. According to Matta criteria for pubic fracture reduction, the result was excellent in 9 cases, good in 6, fair in 1. The Majeed function scores at 6 months after operation was 85.32±8.50; the result was excellent in 8 cases, good in 6 cases, fair in 2 cases.</p><p><b>CONCLUSION</b>The modified Stoppa approach has characteristics of convenience and directness of incisions, clear operation field, easy reduction, few complications and fast recovery , it is an ideal choice in surgical treatment of bilateral pubic fractures.</p>

Locking plate external fixator for the treatment of middle and distal tibial fractures / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the effectiveness of locking plate external fixator in treating middle and distal tibial fractures.</p><p><b>METHODS</b>From January 2010 to January 2013,18 patients suffered from middle and distal tibial fractures were treated by locking plate external fixator,including 11 males and 7 females, with an average age of 53.5 (ranged from 13 to 80) years old,the course of disease ranged from 2 h to 3 d. According to AO classification, 4 cases were type A,11 cases were type B and 3 were type C. Among them,6 patients were open fracture, including 2 cases with type I, 3 cases with type II and 1 case with type III, according to Gustilo classification), 12 patients were close fracture. Operation time, postoperative complications were observed, and Johner-Wruhs scoring were used to evaluate clinical outcomes.</p><p><b>RESULTS</b>All patients were followed up from 6 to 15 (meaned 11) months. Two cases occurred skin necrosis (1 case occurred bone exposure), 2 cases occurred delayed union (all were open fracture), and 1 case occurred nail infection. No screw loosening or broken occurred. According to Johner-Wruhs scoring, 10 cases obtained excellent result,6 cases good,and 2 cases fine.</p><p><b>CONCLUSION</b>Locking plate external fixator for the treatment of middle and distal tibial fractures, which has advantages of lessen damage, shorter operative time, less complications and rapid functional recovery, is one of good choice.</p>

Influencing of chronic low back pain on multifidus muscle atrophy / 中国骨伤

<p><b>OBJECTIVE</b>To identify the affect of chronic low back pain on multifidus muscle atrophy and fatty infiltration.</p><p><b>METHODS</b>From March 2010 to August 2013, a retrospective study were carried out in the department of orthopedics of patients with low back pain. Finally 31 cases were selected to this study including 19 males and 12 females with an average age of 36.4 years ranging from 23 to 55 years. The main symptoms of these patients were repeated back pain. Duration was more than 1 year. X-ray, CT, MRI showed no obvious abnormalities. The changes of net cross-sectional area of multifidus and T2 signal ratio of the same patient were measured at different time by MRI. VAS and Oswestry disability scores were recorded in two MRI examination. Correlation between these change of multifidus net area and T2 signal ratio in two times measurement and duration of low back pain, VAS, Oswestry disability scores were analyzed to find the affection of low back pain on paraspinal multifidus muscle.</p><p><b>RESULTS</b>The net multifidus cross-sectional area in same case by the second follow-up MRI is significantly smaller than that of the first follow-up, T2 signal ratio at second was significantly higher than that of the first (P < 0.05). The net cross sectional area of multifidus muscles reduced rate were positively correlated with VAS scores, duration and of Oswestry disabilitry scores (P < 0.001). The rate of increase in T2 signal ratio was not correlated with VAS scores,duration and the Oswestry disability scores (P > 0.05).</p><p><b>CONCLUSION</b>Chronic low back pain is one of the most important reasons of paraspinal multifidus muscle atrophy and fatty. The duration, VAS and Oswestry disability scores of chronic low back pain were positively correlated with the multifidus muscle atrophy.</p>

Limb preservation surgery combined with perioperative rehabilitation for the treatment of 7 patients with stage II to III giant cell tumor of bone in the proximal humerus / 中国骨伤

<p><b>OBJECTIVE</b>To study the effects of the extensive resection of the tumor-loading segment and artificial humerus head replacement combined with perioperative rehabilitation for the treatment of stage II to III giant cell tumor of bone in the proximal humerus.</p><p><b>METHODS</b>From March 2007 to March 2010, 7 patients with stage II to III giant cell tumor of bone in the proximal humerus were treated. Among the patients, 3 patients were male and 4 patients were female with a mean age of 34.6 years (ranged, 18 to 49 years). The mean course of disease was 19 months (ranged, 6 to 35 months). All the patients were confirmed to suffer stage II to III giant cell tumor of bone in the proximal humerus by pathology and X-ray examinations. Clinical manifestations of the patients included persistence aggravated pain of the shoulder, swelling in the proximate arm with obviously tenderness, activity limited of the joint. All the patients were treated with extensive resection of the tumor-loading segment and artificial humerus head replacement combined with perioperative rehabilitation. CMS and OSIS score system were used to evaluate shoulder function and shoulder stability.</p><p><b>RESULTS</b>All the patients were followed up, and the duration ranged from 14 to 35 months, with an average of 17 months. There were no serious complications or recurrence in all cases. One year after the surgery CMS and OSIS score system were 70.7 scores (ranged,63 to 82 scores) and 25.1 scores (ranged, 18 to 29 scores) respectively. According to evaluation for shoulder function, 2 patients got an excellent result and 5 good. According to evaluation of shoulder stability, 1 patient got an excellent result and 6 good.</p><p><b>CONCLUSION</b>Extensive resection of the tumor-loading segment and artificial humerus head replacement combined with perioperative rehabilitation for the treatment of stage II to III giant cell tumor of bone in the proximal humerus would not only preserve the upper extremity but also preserve the function of upper extremity.</p>

In vivo study of innervation of degenerative intervertebral discs in rabbit anular-injury model / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To observe degenerative intervertebral disc and to examine innervation of degenerative discs in the rabbit anular-injury model.</p><p><b>METHODS</b>Two different magnitudes of anular injury at 5 mm depth were performed by 11 blade or 16 gauge needle at the L3-L4 or L5-L6 discs in New Zealand white rabbits (n=48, 2.5-3.0 kg). Disc degeneration was evaluated by radiographic, MRI and histological examination at different time points after surgery. To identify nerve ingrowth into disc, two general markers PGP 9.5 and GAP 43, for nerve fibers were examined by immunohistochemistry.</p><p><b>RESULT</b>Significant decreases in disc height and signal intensity in magnetic resonance imaging were observed in 11 blade group and 16 G puncture group (P<0.01). 16 G puncture group induced slower and more progressive disc degeneration companed with the stab group and control group. At the 12-week time point, nucleus pulposus tissues were extruded and scar tissues formed outside the disc. In stab discs, nerve ingrowth was scattered on the surface of injury site and in the deeper part of the scar tissues, more than 1 mm from the surface. However, in punctured discs, PGP 9.5 and GAP 43-immunoreative fibers were only observed in the outmost part of the scar tissues and superficial area. More nerve fibers were observed in stab group.</p><p><b>CONCLUSION</b>Innervation may act as a source of discogenic pain which is associated with intervertebral disc degeneration caused by disc anular injury.</p>

Clinical value of minimally invasive posterior lumbar interbody fusion assisted by X-Tube system in the treatment of low back disorders / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the clinical outcomes of minimally invasive posterior lumbar interbody fusion (PLIF) assisted by X-Tube system for the management of degenerative lumbar diseases.</p><p><b>METHODS</b>A total of 31 patients, 17 male and 14 female with ages from 38 to 75 (average 54.2 years), underwent minimally invasive PLIF assisted by the X-Tube system from May 2005 to March 2006. The index diagnosis was lumbar spondylolisthesis in 14 cases, spinal stenosis in 8 cases, separation of the posterior ring apophysis in 5 cases, intervertebral space stenosis with disk herniation in 4 cases. Before operation, conservative management for at least 6 months was proved to be failure in all these patients. The operative duration and blood loss were estimated . The changes of postoperative serum level of creatinine kinase was measured as well, and compared with the control group of 31 cases who were managed with traditional open PLIF operation during the same period at our department. The clinical functional outcomes were evaluated according to Oswestry disability questionnaire.</p><p><b>RESULTS</b>The operation lasted for 140-225 min, with a mean duration of (176 +/- 22) min. Blood loss during the operation was 270-750 ml, with a mean of (406 +/- 96) ml. Postoperative serum level of creatinine kinase was obviously lower in minimally invasive PLIF cases than in the open control cases. Although 2 pedicle screws in 2 cases were not in ideal position, there was no nerve root irritation or fixation failure and hence no revision was required. One case with spinal stenosis complained of numbness in the area dominated by left L5 nerve root after operation, but the symptom was relieved within 2 weeks through conservative management. All the 31 patients were followed up for 7-17 months, with a mean duration of 12.2 months. Lumbar radiography, and three-dimensional CT reconstruction in some cases, was performed and revealed solid fusion of the surgical segments half a year after the operation. The average Oswestry scores decreased from preoperative 40.6 +/- 5.1 to 17.4 +/- 6.5 at the first postoperative day and to 9.5 +/- 4.0 at the final follow-up. The outcome of this operation were rated as excellent.</p><p><b>CONCLUSIONS</b>Minimally invasive PLIF assisted by X-Tube system has the characteristics of less blood loss, tissue trauma and operative time, quick recovery and bony fusion. The short-term outcomes are excellent.</p>

The feature of experimental endplate fracture in lumbar spine and its related factors / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the feature of experimental endplate fracture in lumbar spine and its related factors.</p><p><b>METHODS</b>Nineteen cadaveric lumbar motion segments aged 48 - 77 years were compressed by overload to fracture the endplate and dissected into isolated vertebrae to evaluate feature of their endplate failure. Before and after failure of endplate, radiographic tests were taken on every motion segment. The bone mineral density (BMD), bone mineral content (BMC) of the vertebral body and endplate were tested respectively before endplate fracture.</p><p><b>RESULTS</b>Among 19 motion segments, 16 were fractured and accounted for 84.2% of all and fracture featured as stellate, step, depression and intrusion. Fracture concentrated on the center or anterior of superior endplate of the inferior vertebrae in one motion segment. Failure load of endplate was positively correlated with BMD, BMC of vertebral endplate. Within one vertebral body, the BMD and BMC of its superior endplate was markedly less than that of inferior endplate, on the other hand, the difference of BMD and BMC of endplate around one disc was opposite.</p><p><b>CONCLUSIONS</b>Fractures usually concentrate on the center or anterior part of superior endplate of one vertebrae and are hard to be identified by conventional radiographic examination. Failure load of endplate is positively correlated with BMD, BMC of vertebral body and endplate. There might be certain relationship between feature of fracture and severity of disc degeneration.</p>

Anterior instrumentation for the treatment of tuberculotic spinal deformity / 中华外科杂志

<p><b>OBJECTIVES</b>To summarize the clinical results in the treatment of spinal tuberculosis with debridement, bone grafting and anterior fixation and to evaluate the safety and the value of this procedure.</p><p><b>METHODS</b>From June 1997 to May 2001, 18 patients with spinal tuberculosis were treated using anterior debridement, autograft of bone and primary internal instrumentation. They were 8 men and 10 women, aged from 25 to 59 years (mean 41 years). The degree of kyphosis before surgery was 27.0 degrees to 75.5 degrees (mean 47.5 degrees +/- 11.4 degrees ). The involved spines included cervical spine (1 patient), thoracic spine (10), thoracic-lumbar spine (2), and lumbar spine (5). Average 2.8 intervertebral bodies in each patient were afflicted with tuberculosis disease. Spinal fusions were done with iliac bone grafts.</p><p><b>RESULTS</b>All patients were followed up for an average of 25 months. No deep wound infection and sinus were observed after surgery. The grafted bones were fused in all patients with an average time of 3.6 months. The degree of spine kyphosis correction was 32.7 degrees +/- 8.3 degrees, and 3.2 degrees +/- 2.8 degrees was lost on average in the late stage.</p><p><b>CONCLUSION</b>Anterior instrumentation for spinal tuberculosis could stabilize the spine, correct kyphosis and fuse the grafted bone.</p>

Bone mineral density and bone mineral content in the lumbar vertebrae and the vetebra's biomechanical properties / 中华物理医学与康复杂志

Objective To determine the variation of bone mineral density(BMD)and bone mineral content (BMC)in cadaveric lumbar vertebrae and investigate their significance in determining fracture modes and biomecha- nical properties.Methods The lumbar motion segments of the spines of 19 cadavers(mean age:56 years)were compressed to failure.The BMD and BMC of the cranial and caudal endplates were determined,along with the BMD and BMC of the upper and lower 1/3 transverse sub-endplate layers and the middle 1/3 transverse layer.The anteri- or,middle and posterior 1/3 vertical parts,anterior and posterior 1/2 vertical parts and the whole BMD and BMC were measured by using dual energy X-ray absorptiometry as well.All the data were analyzed statistically.Results Among the 19 segments,macrography after dissection revealed that 16 had been fractured,about 84.2%.The frac- ture always occurred in the centre or in the anterior part of the endplate.Within a vertebral body,the BMD and BMC of the cranial endplate were less than those of the caudal endplate,and the cranial 1/3 transverse layer and middle layer had lower BMD and BMC readings than the caudal layer.For the vertical region,from the anterior 1/3 to the posterior 1/3,or from the anterior 1/2 to the posterior 1/2,the BMD and BMC increased.For the endplate around the disc,the BMD of upper endplate was higher than that of the lower one,but the BMCs were equal.In one motion segment,the failure load correlated positively with BMD,and with the BMC of the endplate and the sub-endplate bone.Conclusion The variations in BMD and BMC within a vertebra and around a disc can explain why vertebral fractures are concentrated on the upper endplate,and why compressive fractures are always wedge-shaped.This un- derstanding can assist in the placement of inter-vertebral spacers.