Clinical efficacy of unilateral percutaneous transfacet screws combined with contralateral pedicle screw versus bilateral pedicle screws fixation in the treatment of the degenerative lumbar disease / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the surgical outcome of unilateral pedicle screw(UPS) after TLIF technique combined with contralateral percutaneous transfacet screw(PTS) fixation vs bilateral pedicle screws(BPS) fixation in treatment of degenerative lumbar disease.</p><p><b>METHODS</b>From January 2009 to June 2012, 46 patients with degenerative lumbar diseases, including 30 males and 16 females with an average age of 51.5 years old, who were divided into two groups according to different fixation methods. Twenty-two cases underwent UPS after TLIF technique combined with contralateral PTS fixation (group A), while the others underwent BPS fixation(group B). The relative data were analyzed, such as blood loss volume, operative time, fusion rate, ODI score, JOA score and so on.</p><p><b>RESULTS</b>All the patients were followed up for 1 to 3 years with an average of 22 months. Except one case of each group was uncertainty fusion, the rest have obtained bony fusion, and the fusion rates in group A and B were 95.5% and 95.8%, respectively. No displacement and breakage of screw were found during follow-up. Operative time and blood loss volume in group A were better than of group B(<0.05). ODI and JOA scores had improved obviously than preoperation(<0.05), but the differences had no statistical significance between two groups(>0.05).</p><p><b>CONCLUSIONS</b>Two approaches had similar clinical outcomes for degenerative lumbar disease with no severe instability. Compared with BPS fixation, the UPS after TLIF technique and contralateral PTS fixation has the advantages of less trauma, shorter operative time and less blood loss, and it is a safe and feasible surgical technique.</p>

Progress on the role of autophagy in spinal cord injury / 中国骨伤

In recent years, the study of autophagy in spinal cord injury (SCI) gradually becomes the hot spot. However, the function of autophagy in the injured spinal cord is still controversial. In order to further understand the role of autophagy after SCI, we summarized the activation of autophagy, autophagic cell death, the relationship between autophagy and apoptosis, the function of autophagy in promoting the molecular metabolism and the role of autophagy after spinal cord injury. We concluded that the role of autophagy after SCI is a double-edged sword. Upregulating the level of autophagy appropriately can promote damaged proteins metabolism and inhibit apoptosis. However, excessive activation of antophagy may induce autophagic cell dealth. So we consider that the proper regulation of autophagy will be a new target in the treatment of SCI.

Treatment of low lumbar degenerative disease with unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation / 中国骨伤

<p><b>OBJECTIVE</b>To explore the operative skills and effect of unilateral pedicle screw combined with contralateral percutaneous transfacet screws fixation in treating degenerative low lumbar disease.</p><p><b>METHODS</b>From January 2009 to December 2011,22 patients with degenerative low lumbar disease were treated with transforaminal lumbar interbody fusion, during the operations, unilateral pedicle screw and contralateral percutaneous transfacet screw fixation were performed. There were 16 males and 6 females, aged from 32 to 71 years old with an average of (51.1 ± 10.6) years, including single segment in 20 cases and two segments in 2 cases. Clinical effects were evaluated according to visual analogue score (VAS) and Oswestry Disability Index (ODI).</p><p><b>RESULTS</b>All patients were followed up from 1 to 2.5 years with an average of 18 months. One case complicated with leakage of cerebrospinal fluid after operation and 1 case with lower limb pain of decompression-side on the 3rd day after operation. Twenty-two patients got bony fusion. There were no instability and evidence of instrument failure during follow-up. The VAS and ODI score decreased from preoperative 8.24 ± 0.72, 36.72 ± 6.84 respectively to 3.18 ± 0.66, 4.36 ± 1.12 at the final follow-up (P < 0.05).</p><p><b>CONCLUSION</b>Unilateral pedicle screw combined with contralateral percutaneous transfacet screw fixation is safe and feasible surgical technique in treating low lumbar degenerative disease. It has advantages of little trauma, rigid fixation, high fusion rate, and less complication. etc.</p>

The Surgical Management of Traumatic Lower Cervical Spondylolisthesis with Posterior Percutaneous Pedicle Screw Fixation

We reported a technical report of traumatic lower cervical spondylolisthesisca used by bilateral pedicle fracture, without neurological compression. The patient was treated with the minimally invasive technique of percutaneous pedicle screw fixation. Fracture healing and normal cervical motion were confirmed by plain films and physical examinations on the 18-monthpostoperatively. The technique of percutaneous pedicle screw fixation might be an alternative strategy for the treatment of traumatic lower cervical spondylolisthesis with pedicle fracture.

Biomechanical characteristics analysis on discs with coflex fixation on the different segments of lower lumbar spine / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the biomechanical differences between the surgery and adjacent segments of intervertebral discs in the lower lumbar spine, which were implanted with Coflex into the segments of L4, and L5S1, respectively.</p><p><b>METHODS</b>Three finite-element models (the model of the intact lower lumbar sacrum,the L4.5 and L5S1 segments implanted by Coflex) were developed, respectively. According to the spinal three-column loading theory, three models were forced by the physiological loads of upright standing, flexion and extension. The stress of the different areas of the disc annulus, the changes of intervertebral dorsal height and the degree of nucleus pulposus pressure were compared and analyzed.</p><p><b>RESULTS</b>Coflex implanted into the L4.5 and L5S1 segments in compression and extension could both decrease the stress of the posterior area of intervertebral disc in the surgery segment, resist the changes of the intervertebral disc dorsal height and reduce the perssure of nucleus pulposus. Furthermore, the stress of the L5S1 segment decreased when Coflex fixed the L4.5 segment in extension. However, when Coflex fixed the L5S1 segment, the stress of L4.5 segment had no significant changes.</p><p><b>CONCLUSION</b>Coflex fixing the L4,5 and L5S1 segments can effectively decrease the stress of the surgery segmental discs, respectively. Furthermore, Coflex fixing L4,5 segment may play a biomechanical role in reducing the stress of L5S1 segment.</p>

The Effect of Postural Correction and Subsequent Balloon Inflation in Deformity Correction of Acute Osteoporotic Vertebral Fractures

OBJECTIVE: To determine deformity correction by postural correction and subsequent balloon inflation in acute vertebral compression fractures (OVCFs) and to examine the effect of bone mineral density on deformity correction. METHODS: A totol of 50 acute OVCFs received balloon kyphoplasty. Lateral radiographs were taken and analyzed at five different time points : 1) preoperative, 2) after placing the patient in prone hyperextended position, 3) after balloon inflation, 4) after deposition of the cement, and 5) postoperative. All fractures were analyzed for height restoration of anterior (Ha), middle (Hm) and posterior (Hp) vertebra as well as Cobb angle and Kyphotic angle. The bone mineral density (BMD) of lumbar spine was measured by dual-energy X-ray absorptiometry. According to the T-score, the patients were divided into two groups which were osteoporosis group and osteopenia group. RESULTS: Postoperative measurements of Ha, Hm and the Cobb angle demonstrated significant reduction of 4.62 mm, 3.66 mm and 5.34degrees compared with the preoperative measurements, respectively (each p<0.05). Postural correction significantly increased Ha by 5.51 mm, Hm by 4.35 mm and improved the Cobb angle by 8.32degrees (each p<0.05). Balloon inflation did not demonstrate a significant improvement of Ha, Hm or the Cobb angle compared with baseline prone hyperextended. Postural correction led to greater improvements of Ha, Hm and Cobb angle in osteoporosis group than osteopenia group (each p<0.05). CONCLUSION: In acute OVCFs, the height restoration was mainly attributed to postural correction rather than deformity correction by balloon inflation. BMD affected deformity correction in the process of postural correction.

Development of shear force-induced intervertebral disc degeneration model / 医用生物力学

Objective To develop a shear force-induced intervertebral disc degeneration (IDD) in vivo animal model, and investigate the relationship between shear stress and IDD. Methods A total of 20 Japanese white rabbits were randomly divided into two groups. In loading group (n=10), shear force of 50 N was applied on the disc of L4/5 for 4 weeks by a custom-made external shear force loading device. In control group (n=10), the animals underwent a sham operation with the external loading device situated, but their discs remained unloaded. After 4 weeks, all the intervertebral discs of L4/5 were executed for the pathologic examination. Results The postoperative radiographic examination showed a perfect position of the loading device, and the operation process and implanted loading device had no effect on daily activities and diet of the experiment animals. The pathological examination showed an irregular arrangement of annulus fibrosus and a significant decrease of normal nucleus pulposus cells in loading group. Conclusions The new custom made device greatly reduced the wounds on animal vertebra and provided a reliable shear force. The development of in vivo animal model indicates that IDD can be induced by shear force, which is of significance to further study the relationship between loading and IDD.

Finite element model testing on Coflex dynamic fixation for L4/5 and L5/S1 segment of lower lumbar / 医用生物力学

Objective To simulate clinical operation and investigate feasibility of Coflex dynamic device for fixing L5/S1 segment of lower lumbar degenerative diseases. Methods The lower lumbar-sacral digital model was extracted from platform of the second generation of Chinese Digitized Human “Male No.23” data set, and three finite element (FE) models (the model of normal lower lumbar sacrum, L4/5 and L5/S1 segment fixed with Coflex) were developed respectively using a series of CAX software. According to the spinal three-column loading theory and the lower lumbar physiological behaviors, FE model tests were analyzed, validated and compared under the physiological load of upright standing, anteflexion and extension. Results The FE models of normal lower lumbar sacrum (Healthy), Coflex fixed-L4/5 segment (L4/5), Coflex fixed-L5/S1 segment (L5/S1) were developed, respectively. Based on biomechanical indexes (stability and compatibility) of the controlled trial for the FE model, the two Coflex-fixed FE models showed similar biomechanical effects for fixing the lower lumbar. Conclusions The controlled trials of FE models provide biomechanical evidence for the fixation of lower lumbar L5/S1 segment by Coflex dynamic device, which is of significance for application of Coflex in fixing L5/S1 segment in clinic.

Discectomy and discectomy plus Coflex fixation for lumbar disc herniation, a clinical comparison study / 中华外科杂志

<p><b>OBJECTIVE</b>To compare clinical efficacy between discectomy and discectomy plus Coflex fixation for lumbar disc herniation.</p><p><b>METHODS</b>From December 2007 to August 2008, 50 patients (31 males and 19 females) were treated by surgery of discectomy and discectomy plus Coflex fixation. The average age was 52.5 years (range, 30 - 72 years). There were 24 cases in the group of discectomy plus Coflex fixation and 26 cases in the group of discectomy. Preoperative and postoperative visual analogue scales (VAS), Japanese Orthopadic Association (JOA) and Oswestry disability index (ODI) were recorded, as well as radiological index. And use a paired t-test and one-way analysis of variance (one-way ANOVA) statistical method to evaluate the Coflex dynamic stabilization system in value in the treatment of lumbar disc herniation.</p><p><b>RESULTS</b>Both groups received significant improvement of JOA, ODI and VAS (t = -33.2 - 64.5, P < 0.01), but the group of discectomy was found with deterioration of ODI at last follow-up, 12 months after surgery 6.7 ± 1.5 to 10.2 ± 2.3 (t = -19.3, P < 0.05). The group of discectomy plus Coflex fixation was found with significant increase of height of dorsal intervertebral discs (HD), distance across the two adjacent spinous processes (DS), distance of intervertebral foramina (DIF) and spinal canal area(SA) (t = -34.4 - 4.5, P < 0.05). In contrast, the group of discectomy was found with significant decrease of HD, DS, DIF and SA (t = 3.4 - 52.8, P < 0.05). Coflex fixed group in HD, DIF, DS significant difference with simple discectomy group, with a statistically significant (F = 14.1 - 25.6, P < 0.05).</p><p><b>CONCLUSIONS</b>Both discectomy and discectomy plus Coflex fixation are apparently effective when treating lumbar disc herniation. Coflex can significantly increase the HD and DIF when used for lumbar disc herniation, and it has positive influence for keeping height of lumbar vertebral space and treating the nerve root symptom of lumbar disc herniation. Discectomy plus Coflex is better than pure discectomy in preventing lumbar degeneration.</p>

Clinical evaluation of interspinous process device Coflex for degenerative disk diseases / 中华外科杂志

<p><b>OBJECTIVE</b>To study indications and complications of interspinous process device Coflex for degenerative disk diseases.</p><p><b>METHODS</b>One hundred and eight patients with degenerative lumbar disc diseases were underwent procedures of surgical decompression and additional fixation of Coflex between November 2007 and October 2010. Sixty-eight patients were male and the other fourty were female, and their average age was 53.5 years (range from 37 to 75 years). Fifty-nine patients were underwent surgery of excision of nucleus pulposus and Coflex fixation, 41 patients were underwent surgery of decompression by fenestration and Coflex fixation, 6 patients were underwent surgery of topping-off, and 2 patients were underwent surgery of Coflex fixation for two level. Preoperative and postoperative visual analogue scales (VAS) and Oswestry disability index (ODI) were recorded, as well as height of ventral intervertebral space (HV), height of dorsal intervertebral space (HD), height of intervertebral foramen (HIF) and segmental range of motion (ROM). One-way ANOVA was used for statistical analysis. Surgical complications were also recorded.</p><p><b>RESULTS</b>The average follow-up time was 28.8 months. All groups had apparent improvement of VAS and ODI, and maintained well to last follow-up (F = 6.16-25.92, P = 0.00). Statistical analysis showed that HD and HIF increased significantly in group with excision of nucleus pulposus and Coflex fixation and group with decompression by fenestration and Coflex fixation (F = 7.37 - 11.68, P < 0.05). Although both HD and HIF decreased one-year after surgery, they were still higher than those preoperatively (F = 6.31 and 7.05, P = 0.00). Preoperative segmental ROM was respectively 6.3° ± 1.8° and 6.2° ± 1.7° in group with excision of nucleus pulposus and Coflex fixation and group with decompression by fenestration and Coflex fixation, and 3.1° ± 0.6° and 3.0° ± 0.8° at last follow-up. Three cases were found with device-related complications and five with non-device-related complications, and all five cased were cured after appropriate treatment.</p><p><b>CONCLUSIONS</b>Surgical method assisted with Coflex has significant clinical efficacy for degenerative disc disease, it can maintain segmental stability, simultaneously, partly reserve movement. It's key to strictly master indications and precisely choose patients.</p>

Effects of surface roughness of bone cements on histological characteristics of induced membranes / 中国骨伤

<p><b>OBJECTIVE</b>To explore surface roughness of bone cement and surround tissue on histological characteristic of induced membranes.</p><p><b>METHODS</b>Bone cements with smooth and rough surface were implanted in radius bone defect, intramuscular and subcutaneous sites of rabbits, and formed induced membranes. Membranes were obtained and stained (HE) 6 weeks later. Images of membrane tissue were obtained and analyzed with an automated image analysis system. Five histological parameters of membranes were measured with thickness,area,cell density,ECM density and microvessel density. Double factor variance analysis was used to evaluate the effect of the two factors on histological characteristics of induced membranes.</p><p><b>RESULTS</b>Membranes can be induced by each kind of bone cement and at all the three tissue sites. In histological parameters of thickness,area and micro vessel,there were significant differences among the membranes induced at different tissue sites (P = 0.000, P = 0.000, P = 0.000); whereas, there were no significant differences in histological parameters of cell density and ECM density (P = 0.734, P = 0.638). In all five histological parameters of membranes, there were no significant differences between the membranes induced by bone cements with different surface roughness (P = 0.506, P = 0.185, P = 0.883, P = 0.093, P = 0.918).</p><p><b>CONCLUSION</b>Surround tissue rather than surface roughness of bone cements can affect the histological characteristics of induced membranes. The fibrocystic number, vascularity, mechanical tension and micro motion of the surround tissue may be closely correlated with the histological characteristics of induced membranes.</p>

Influence of intravertebral cleft for outcome of percutaneous kyphoplasty / 中华外科杂志

<p><b>OBJECTIVES</b>To study incidence and radiological features of intravertebral cleft (IVC) in patients with chronic pain due to osteoporotic vertebral compression fractures (OVCFs), and analyze influence of IVC for surgery of percutaneous kyphoplasty (PKP).</p><p><b>METHODS</b>Seventy-six patients with osteoporotic vertebral compression fractures and pain duration more than one month were underwent procedures of PKP between August 2005 and August 2010. The incidence and radiological features of IVC were analyzed. Sixty-one patients with single-level OVCFs were divided into two groups with and without IVC. Preoperative and postoperative kyphotic angle and relative anterior vertebral height were recorded, as well as visual analogue scales (VAS) and Oswestry disability index (ODI). Cement patterns of opacification and leakage were also recorded.</p><p><b>RESULTS</b>Thirty two patients with 39 vertebrates were found with IVC sign. The diagnostic sensitivity of X ray, CT and MRI for IVC was respectively 33.3%, 85.7% and 84.6%. Two groups with IVC and without IVC both had apparent correction of kyphotic angle and reduction of anterior height at 3 days after surgery and last follow-up (F = 21.82 - 72.18, P < 0.01). There was no statistical significance between two groups (P > 0.05). In addition, both groups had significant improvement as regard to VAS and ODI (F = 131.06 - 364.12, P < 0.01). Solid pattern accounted for 72.0% of all cemented vertebrates in the group with IVC and 19.4% in the group without IVC. Four cement leakage were found in the group with IVC and another four in the group without IVC.</p><p><b>CONCLUSIONS</b>There is a high incidence of IVC in patients with chronic pain due to osteoporotic vertebral compression fractures. CT and MRI are sensitive for detection of IVC. The procedure of PKP is effective for both groups with and without IVC. IVC produces an apparent influence on cement opacification and leakage location during the procedure of PKP.</p>

Development of an experimental device for measuring three-dimensional movement of the spine / 医用生物力学

Objective To develop a set of loading device that can simulate the spinal movement in vitro so as to carry out the biomechanical experiment on human spine. Methods Based on the principle of bearing, the rotary locking device was designed and fixed on the loading plate, which was rotated to the position for testing and then locked by the bolt before loading. And then, with the auto-loading power provided by the universal testing machine, the pure moment of flexion/extension, left/right bending and left/right axial rotation were applied on the spine specimen to simulate the spinal movement in vivo. Finally, the position of the spine specimen before/after loading was measured by the 3D scanner. With the loading device, the range of motion under these six loading conditions for six fresh (one-year age) porcine cervical spines (C2-C6) was tested, and precision of the loading device as well as error analysis were testified by experiments. Results A set of experimental device for the three-dimensional movement measuring for human spine was developed. Data of neutral zone and range of motion for the porcine cervical spine in six directions were acquired with the total measurement error being less than 3.5％. Conclusions The delicate design of this loading device could simulate the spinal motion in vitro and thus achieve the rapid loading of the human spine. This is an inexpensive, simple and practical device, which can significantly increase the test efficiency and has great application value in loading on the spine in vitro.

Analysis of outcome and prognostic factors of anterior approach for two-level cervical spondylotic myelopathy / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the efficacy and possibly prognositic factors of anterior approach on two-level cervical spondylotic myelopathy.</p><p><b>METHODS</b>A retrospective review was performed on 44 cases of two-level cervical spondylotic mydopathy from Jun. 2007 to Sep. 2009. Among the patients, 24 cases were male and 20 cases female, with an average age of (60.072 +/- 10.77) years (ranged from 39 to 80 years). The affected segments ranged from C(3.4)-C(6.7). Improvements of cervical curvature and segmental height, preoperative sagittal diameter of the spinal cord at the site of maximal compression and signal intensity changes on T2WI were respectively measured. Function of nerves was assessed according to Japanese orthopaedic association system (JOA:17 score) before and after surgery. Operation by anterior approach including: anterior corpectomy and titanium cage fusion with internal fixation, anterior corpectomy body and auto iliac bone fusion with internal fixation. Statistical analysis was made on the correlation between JOA recovery rate and prognostic factors.</p><p><b>RESULTS</b>Improvements of cervical curvature was -9.1 degrees to 16.6 degrees with the mean of (1.30 +/- 5.77) degrees and improvements of segmental height was -0.3 to 12.3 mm with the mean of (4.23 +/- 3.08) mm. Sagittal diameter of the spinal cord at the site of maximal compression was 1.6 to 7.2 mm with the mean of (4.01+/- 1.25) mm. T2WI with high signal changes was in 29 cases, no change in 15 cases. Bleeding amount was 50 to 700 ml with the mean of (242.05 +/- 148.22) ml. Operative time was 90 to 250 min with the mean of (153.75 +/- 34.54) min. All patients were followed up from 6 to 31 months with an average of (17.18 +/- 7.41) months. The mean JOA score preoperatively was (12.73 +/- 2.23); at the final follow-up, the JOA score was(15.09 +/- 1.91); and the recovery rate was (60.01 +/- 26.98)%. According to standard of JOA scoring, 16 cases obtained excellent result, 12 good, 15 fair and 1 poor. The effect of anterior approach had correlations with age, time of course, preoperative JOA score, sagittal diameter of the spinal cord at the site of maximal compression and signal intensity changes on T2WI, but had no correlations with operation time, bleeding amount and improvements of cervical curvature and segmental height.</p><p><b>CONCLUSION</b>Two-level cervical spondylotic myelopathy can achieve good effect through anterior approach. The extent of the spinal cord compression may be a reliable and direct factor to judge effect.</p>

Application of anterior percutaneous screw fixation in treatment of odontoid process fractures in aged people / 中国骨伤

<p><b>OBJECTIVE</b>To explore the efficacy of anterior percutaneous screw fixation in the treatment of odontoid process fractures in aged people.</p><p><b>METHODS</b>From February 2001 to April 2009, 15 elderly patients with odontoid fracture were treated with anterior percutaneous screw fixation,including 13 males and 2 females; the average age was 69.3 years (ranged, 60 to 86 years). According to Anderson classification, there were 10 patients with type II fractures (type II A in 7 cases, type II B in 3 cases, based on Eysel and Roosen classification), 4 patients with shallow type III fractures, 1 patient with deep type III fractures. Thirteen patients were fresh fractures, 2 patients were obsolete fractures. All patients had varying degrees of neck or shoulder pain, and limit activity of neck. There were 4 patients with neural symptoms including 2 grade D and 2 grade C according to Frankel classification. All the patients were followed up and were assessed by radiology. Clinical examination included neck activity, neurological function and the degree of neck pain. Radiology examinations including anteroposterior, lateral, open mouth position and flexion-extension radiographs of cervical vertebra were performed.</p><p><b>RESULTS</b>After surgery, all patients were followed up,and the duration ranged from 6 to 60 months (averaged 31.3 months). Two patients died of other diseases during the follow-up period (18 and 22 months after surgery respectively). All patients got satisfactory results, and all screws were in good position. As the screw was too long, esophagus was compressed by screw tail in one case. One case showed fibrous union, 12 cases had achieved solid bony union, 2 cases showed nonunion without clinical symptoms. The rotation of neck in 3 cases was mildly limited,the neck function of the remaining patients were normal. Four patients with symptoms nerve injuries improved after operation (Frankel E in 3 cases, Frankel D in 1 case). The symptom of neck pain had a significant improvement after surgery (P < 0.001). The VAS score decreased from preoperative (6.07 +/- 1.44) (4 to 8 scores),to postoperative (1.13 +/- 0.92) (0 to 3 scores). And there were no severe postoperative complications.</p><p><b>CONCLUSION</b>The anterior percutaneous screw fixation is less traumatic than conventional approaches for aged people in dealing with odontoid process fractures. Most patients will achieve satisfactory clinical results, as long as the general conditions of them are comprehensively assess. However, this procedure should not be used in patients with comminuted odontoid fractures or severe osteoporosis.</p>

Analysis and strategy on the early complications of lumbar disc herniation with Coflex system / 中国骨伤

<p><b>OBJECTIVE</b>To explore the short-term effectiveness and the cause of the early complications of lumbar disc herniation with Coflex system in order to provide evidence for the prevention.</p><p><b>METHODS</b>From November 2007 to August 2008, 37 patients (20 males and 17 females) were treated with Coflex system. The age was from 33 to 70 years with an average of 52 years and the history was from 6 to 50 months with an average of 16.5 years. Complications were observed and the short-term effectiveness was evaluated by scores of JOA and ODI before and after operation.</p><p><b>RESULTS</b>All patients were followed up from 1 to 2 years with an average 20 months. The JOA score increased from 9.09 +/- 1.10 preoperatively to 25.40 +/- 1.20 in the last follow-up. ODI decreased from 24.70 +/- 4.80 preoperatively to 4.80 +/- 1.00 in the last follow-up. The VAS score decreased from 7.86 +/- 0.80 preoperatively to 3.20 +/- 0.50 in the last follow-up. The symptoms remarkably improved. Complications occurred in 4 pa-tients (10.8%), among them, persistent low back pain was in 1 case and conservative treatment did not work; opposite lower limb pain was in 1 case at the 3rd week after operation and symptomatic treatment was effective; displacement of Coflex was in 1 case and Coflex breakage happened in 1 case at the 6th month after operation, but both did not have related clinical symptom.</p><p><b>CONCLUSION</b>Coflex can obtain good clinical outcomes in treating lumbar disc herniation, but it has special complications. The indications and manipulations should be chosen properly.</p>

Prediction of spinal cord decompression after cervical laminoplasty: the SC-line / 中华外科杂志

<p><b>OBJECTIVES</b>To report a new index (the SC-line) and a new classification for predicting of postoperative spinal cord decompression after cervical laminoplasty.</p><p><b>METHODS</b>From March 2008 to August 2009, MRI images of 25 patients treated with cervical laminoplasty were retrospectively studied. Using T2-weighted images of the cervical spine, point A was anterior point of the spinal cord at inferior endplate level of cranial compressed vertebra. Point B was anterior point of the spinal cord at superior endplate level of caudal compressed vertebra. The SC-line was defined as a line that connects A and B. Posterior surface of compressor at compression level did not exceed the line in Type I, connected the line in Type II, and exceeded it in Type III. Twenty-five patients who underwent cervical laminoplasty were classified into 3 groups according to the SC-line classification. The posterior shift of the spinal cord after the posterior decompression procedure was evaluated by using a modified gradation of degree of anterior spinal cord compression by MRI finding. The relationship between the degree of anterior spinal cord compression after surgery and the SC-line types were analyzed.</p><p><b>RESULTS</b>Preoperative cervical SC-line classification showed high correlations to the degree of spinal cord decompression. There were 3.82 ± 0.39 points in Type I before surgery, 3.90 ± 0.32 points in Type II, and 4.00 ± 0.00 points in Type III, respectively. After surgery, there were 1.15 ± 0.50 points in Type I, 2.70 ± 0.48 points in Type II, and 3.50 ± 0.55 points in Type III, respectively. Significant differences were found between each Type (F = 42.49, P < 0.01; Type I vs. Type II: P < 0.01; Type I vs. Type III: P < 0.01; Type II vs. Type III: P = 0.038).</p><p><b>CONCLUSION</b>SC-line can be used to predict the degree of postoperative spinal cord decompression following cervical laminoplasty.</p>

Analysis on morbidity factor of bilateral intertrochanteric fractures / 中国骨伤

<p><b>OBJECTIVE</b>To study the morbidity factors of bilateral intertrochanteric fractures by analyzing medical records, so as to provide evidences for preventing the multiple intertrochanteric fractures.</p><p><b>METHODS</b>From Janurary 2000 to June 2009, 68 patients with bilateral intertrochanteric fractures were studied, including 31 males and 37 females, ranging in age from 42 to 95 years with an average age of 75 years. There were type A1 in 24 hips, type A2 in 96 hips, and type B3 in 16 hips. One hundred and twenty-eight hips had received surgical treatment, 8 hips were treated with conservative method. On the first injury, 67 patients discharged after treatment, 1 patients discharged after treatment in other department. On the second injury, 58 patients discharged after treatment, 2 patients died of complications, 8 patients dischagred after treatment in other department. The risk factors including age, cause of injury, fractures type, complications, osteoporosis and treatment were analyzed.</p><p><b>RESULTS</b>The average age of two fractures were (73.6 +/- 9.25) and (76.7 +/- 6.74) years; the major injury cause was fall; the A2-type fractures went up to 80.88% on the secondary injury;and the proportion of complications was high, mainly geriatric cognitive disorders, hemiplegic paralysis, and dysopia. Bone mineral density measurement of 16 cases showed marked osteoporosis.</p><p><b>CONCLUSION</b>Osteoporosis and fall injury contribute mostly to the multiple intertrochanteric fractures. Complication was the dominating risk factor. Treatment of osteoporosis, intensive care, postoperative rehabilitation and effective initial surgery are the key to prevent the secondary intertrochanteric fractures in old people.</p>

Therapeutic effects and complications of percutaneous pedicle screw fixation for thoracolumbar fractures / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the therapeutic effects and complications of percutaneous pedicle screw fixation for thoracolumbar fractures.</p><p><b>METHODS</b>From January 2002 to December 2008, 103 patients with thoracolumbar fractures were treated with percutaneous pedicle screw fixation, including 75 males and 28 females, the average age was 45.6 years (range, 18 - 72 years). All of them were of no neurological deficits. There were 65 cases of traffic injury, 23 cases of fall injury and 15 cases of smashed injury. According to the Denis classification, 64 patients were of compression fractures, and 39 patients of burst fractures. There were 5 cases had fractures in T(11), 30 in T(12), 42 in L(1), 15 in L(2), 4 in L(3), 3 in L(4), 2 in T(11-12), 1 in L(1-2), and 1 in L(2-3). Radiological examinations, including X-ray and CT examinations, and clinical examinations were carried out to evaluate the therapeutic effects.</p><p><b>RESULTS</b>Twenty one patients were lost to follow up, the remaining were followed up from 10 to 48 months with an average of 27.4 months. Before the operation, the vertebral height, the kyphosis angle and the occupation of spinal canal were (54.5 ± 8.7)%, 16.4° ± 2.9° and 1.2 ± 1.0, and were improved to (88.6 ± 6.4)%, 11.6° ± 2.7° and 0.5 ± 0.6 respectively after the operation. Preoperatively the visual analogue scale and the Oswestry disability index were 8.0 ± 1.2 and 41.2 ± 9.3, and were improved to 1.7 ± 1.8 and 6.7 ± 5.6 postoperatively, respectively. All of these values between pre- and post-operatively were significantly different (P < 0.01). Screw misplacement was found in 7 patients, superficial wound infection in 1, screw breakage in 3, screw dislodgment in 2, cement leakage in 5, transient neurological symptoms in 4, and 8 patients with low back pain remained, of which 2 patients required occasional oral analgesics. Bone fusion achieved in all cases.</p><p><b>CONCLUSIONS</b>The clinical efficacy of percutaneous pedicle screw fixation is similar with conventional open surgery. With the advantages of convenient procedure, less invasive, and rapid recovery, percutaneous pedicle screw fixation is an alternative method for thoracolumbar fractures without neurological deficits.</p>

The application of minimally invasive surgery for different type of thoracolumbar fractures / 中华外科杂志

<p><b>OBJECTIVE</b>To study the therapeutic method and effect of minimally invasive surgery for the thoracolumbar fractures.</p><p><b>METHODS</b>A retrospective review of the minimally invasive surgically treatment thoracolumbar fractures from February 2005 to June 2010 was performed. There were 183 cases, 126 males and 57 females, aged 18 to 68 years, average 38.9 years. The involved levels of fractures were T(11) in 22, T(12) in 61, L(1) in 71, L(2) in 29. According to Gertzbein classification, 145 cases were type A fractures, 34 cases were type B fractures, 4 cases were type C fractures; According to Load-sharing score, 51 cases were 4 scores, 56 cases were 5 scores, 17 cases were 6 scores, 12 cases were 7 scores, 24 cases were 8 scores, 23 cases were 9 scores. Different surgical methods were selected according to the minimally invasive surgical strategy, 22 patients were treated with the minimally invasive percutaneous pedicle screws osteosynthesis (MIPPSO group), 102 patients were treated with the small-incision pedicle screws osteosynthesis (SISPSO group), 31 patients were treated with the small incision anterior thoracolumbar surgery (SIATS group) assisted by thoracoscope or headlight, and 28 patients were treated with the 270° decompression and reconstruction surgery (270° DRS group) via a posterior small incision. Preoperative and postoperative neurological status, the correction and loss of Cobb's angle, the decompression scope of spinal canal, the location and union of bone graft were followed up and reviewed.</p><p><b>RESULTS</b>All of 183 cases had successful surgery and were followed up. In the MIPPSO group, operative time was 52 - 100 min, blood loss was 35 - 55 ml. In the the SISPSO group, operative time was 48-68 min, the blood loss was 45 - 65 ml the correction of Cobb's angle in the two groups was 8° - 19°. In the SIATS group, operative time was 140 - 220 min, the blood loss was 160 - 1500 ml the correction of Cobb's angle was 15° - 25°, 1 case had pleural effusion, 1 had lateral femoral cutaneous nerve damage, the complications disappeared after treatment. In the 270° DRS group the operative time was 160-280 min, the blood loss was 700 - 4700 ml, the correction of Cobb's angle was 15° - 28°. The spinal canal mass was removed, the spinal canal was enlarged and completely decompressed. Neurological status improved in all of the preoperative incomplete paraplegia patients except 1 case whose neurological symptoms aggravated.</p><p><b>CONCLUSION</b>It is satisfactory that the minimally invasive surgical strategy was rational used in the treatment of thoracolumbar fractures.</p>