Predictive value of three surgical scoring systems for estimation of life expectancy in patients with extradural spinal metastasis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the predictive values of Tokuhashi score, revised Tokuhashi score and Tomita score systems for life expectancy and treatment options in patients with spinal metastasis.</p><p><b>METHODS</b>From February 1996 to January 2009, spinal operations in 104 cases with spinal metastasis were performed in our hospital. There were 65 males and 39 females, with an average of 53.4 years (median 52.5 years). To calculate AUC (area under the curve) values of Receiver Operating Characteristic (ROC) curves of three scores, and to analyze the accuracy of prediction of life expectancy. To compare the actual survival time with the expected survival time of the three scores by Kaplan-Meier method. Spearman correlation analysis was performed between the survival time and three scoring systems.</p><p><b>RESULTS</b>All cases were followed-up with an average duration of 10.9 months, and 77 patients died. AUC analysis of ROC curves showed that the difference of the accuracy of the three scores was not significant. AUC in all groups of Tokuhashi Score was low, with a poor diagnostic accuracy. In the "died within 3 months" and "died within 6 months" groups of revised Tokuhashi score, the accuracy was low, while high in the other two groups. The AUC values of Tomita score in "died within 6 months" and "died within 24 months" were high, with a great diagnostic accuracy while the other two groups were low with a low diagnostic accuracy. Kaplan-Meier survival curve analysis showed that the actual survival time in all three scores was not entirely consistent with the expected survival time. Tokuhashi score and revised score were positively correlated with the survival time while that of Tomita score was negative.</p><p><b>CONCLUSION</b>All the three prognosis scores in patients with spinal metastasis were closely related with survival time. The combination of Tokuhashi score and Tomita score may be applied to better predict postoperative survival prognosis and guide the surgical options for patients with spinal metastasis.</p>

Evaluation of the role of combined TES-MEP and CSEP monitoring during the spinal surgery / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate of the role of transcranial electrical stimulation motor evoked potential (TES-MEP) in combination with cortical somatosensory evoked potential (CSEP) monitoring during the spinal surgery.</p><p><b>METHODS</b>TES-MEP on bilateral anterior tibial muscle and flexor hallucal brevis and CSEP on bilateral posterior tibial nerve were observed simultaneously on 293 patients during spinal surgery from July 2006 to April 2009. Intravenous anesthesia was employed in all the patients, a part of which were added low dose of sevoflurane or muscle relaxant. The results of TES-MEP, CSEP and combined monitoring were analyzed statistically. Pre-operative and post-operative motor and sensory functions of spinal cord were compared.</p><p><b>RESULTS</b>Success rate of TES-MEP, CSEP and combined monitoring was 90.8%, 96.9% and 100% respectively. For the judgment of motor function of spinal cord, the sensitivity of TES-MEP and CSEP was 100% and 89.3% respectively and the specificity of 98.4% and 96.9%. The Youden index of the two methods was 0.984 and 0.862. For sensory function, the sensitivity of them was 76.7% and 93.3% respectively and the specificity of 98.7% and 98.0%. The Youden index was 0.754 and 0.913. The sensitivity of combined monitoring was 100%, with the specificity of 96.9%. The Youden index was 0.969.</p><p><b>CONCLUSIONS</b>The precision of monitoring motor function of spinal cord with TES-MEP is higher than that with CSEP, however, for sensory function, CSEP is more precise. The sensitivity and precision of combined monitoring for spinal cord function were apparently better than that of unitary TES-MEP or CSEP. The combined TES-MEP and CSEP monitoring is a relatively ideal method.</p>

Experimental study on spinal fusion induced by hBMP-4 gene modified tissue engineered bone / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy of hBMP-4 gene modified tissue engineered bone graft in the enhancement of rabbit spinal fusion and find an ideal kind of substitute for the autograft bone.</p><p><b>METHODS</b>Rabbit BMSCs were cultured and transfected with AAV-hBMP-4 using different MOI value. The optimal MOI value were determined by observing cell's morphology change. BMSCs were then transfected with AAV-hBMP4 and AAV-EGFP respectively, following which the transfected cells were evenly suspended in a collagen sponge I, and implanted to either side of the L5,6 intertransverse spaces posterolateral in the New Zealand rabbits to induce spinal fusion. Fourteen rabbits were randomly divided into 2 groups. Group 1: AAV-hBMP-4 transfected BMSCs in the right side (hBMP-4 side) and autograft bone in the left side. Group 2: AAV-hBMP-4 transfected BMSCs in the right side (hBMP-4 side) and AAV-EGFP transfected BMSCs in the left side (EGFP side). Radiographs and three-dimensional CT of the spine, manual palpation, gross and histological examination of the fusion masses for all the animals were performed subsequent to animals having been sacrificed at 12 weeks after surgery.</p><p><b>RESULTS</b>Evaluation has been taken in 12 New Zealand rabbits delivered into 2 groups which meet the criterion after operation. Eleven in 12 implemented sides involved hBMP-4 achieved bony fusion, to which 5 in 6 autografted sides was similar. But only 2 in 6 sides in EGFP-group achieved bony fusion meanwhile. Three-dimensional CT scan and palpation also evidenced the results. Bone formation was observed obviously on specimen both in hBMP4 sides and autografted ones. EGFP-group also got bony integration, but the quantity was small.</p><p><b>CONCLUSION</b>Tissue-engineered bone graft constructed from application of hBMP4 is a fine substitute for autograft. Effective enhancement of bony integration in spinal fusion surgery has been evidenced in vivo.</p>

Biomechanical effect of the iliac screw insertion depth on lumbo-iliac fixation construct / 中华外科杂志

<p><b>OBJECTIVE</b>To biomechanically compare the stability of the short and long iliac screw fixation constructs in lumbo-iliac reconstruction.</p><p><b>METHODS</b>Seven adult human embalmed cadavers (L(3)-pelvis) were used. Using posterior spinal fixation system, L(4)-S(1) pedicle screw fixation was performed. This was defined as intact state of the sacroiliac joint. After the intact test, total sacrum resection and L(4)-L(5)-pelvis reconstruction by pedicle screw and iliac screw with different lengths were performed as follow: short screw group (as the length of exceeding 2 mm over ischial notch) and long screw group (as the length of exceeding 2 mm over anterior inferior iliac spine). Using the 858 MTS material testing machine, biomechanical testing was performed under 800 N compression and 7 Nm torsion loading modes. At last, the axial pullout test of two iliac screws was executed. Construct stiffness in compression and torsion test, and maximum pullout force were analyzed.</p><p><b>RESULTS</b>Insertion lengths of the short and long iliac screw were (70 +/- 2) mm and (138 +/- 4) mm respectively. The lumbo-pelvic reconstruction using short and long iliac screw, respectively restored 53.3% +/- 13.6% and 57.6% +/- 16.2% of the initial stiffness in compression testing, and respectively harvested 55.1% +/- 11.9% and 62.5% +/- 9.2% of the initial stiffness in torsion testing. No significant difference was detected between the two reconstructions (P > 0.05), however, the compressive and torsional stiffness of the two techniques were markedly less than the intact condition (P < 0.05). The maximum pullout strength of long iliac screw was significantly higher than short screw (P < 0.05).</p><p><b>CONCLUSIONS</b>Under the physical loading, lumbo-pelvic fixation construct using the short iliac screw may obtain mechanical stability comparable to that by long iliac screw. The short iliac screw is only the half of the long iliac screw by length, could reduce the implantation risk. However, the long iliac screw behaves greater axial pullout force, should be applied as far as possible in the osteoporosis patient. The lumbo-pelvic reconstruction utilizing any length of iliac screw is difficult to restore the local stability.</p>

Determination of painful vertebrae treated by kyphoplasty in multiple-level vertebral compression fractures / 中华外科杂志

<p><b>OBJECTIVE</b>To explore how to determine painful vertebrae treated by kyphoplasty in multiple-level osteoporotic vertebral compression fractures and clinical outcome.</p><p><b>METHODS</b>From October 2002 to June 2005, 51 consecutive procedures with kyphoplasty were performed on 35 patients with multiple-level osteoporotic vertebral compression fractures. There were 51 painful vertebrae among 120 vertebral compression fractures. The painful vertebra was determined by the signal intensity changes in MR images, combined with radiography and local percussion pain before operation. Only painful vertebrae were treated by kyphoplasty. Preoperative, postoperative and final follow-up visual analog scale (VAS) and radiographic findings such as vertebral height and Cobb angle were recorded and analyzed.</p><p><b>RESULTS</b>All patients tolerated the procedure well with immediate relief of their back pain after kyphoplasty and they can walk at 1-3 days after the procedure. There were 3 vertebrae (3/51) occurred asymptomatic extravasation of cement. 31 cases were followed up for mean 16.2 months (range 6-44 months). VAS reduced from preoperative 8.7 to final follow-up 2.1 (P <0. 01). At final follow-up the vertebral height had a recovery rate of 59.17%, and the mean Cobb angle was improved 10.1 degrees. There was a significant improvement between preoperative and final follow-up values (P < 0.01).</p><p><b>CONCLUSIONS</b>The painful vertebra can be determined by signal intensity changes in MR series images in multiple-level osteoporotic vertebral compression fractures. Selecting painful vertebrae to be treated by kyphoplasty can make patients with multiple-level VCFs gain an excellent result.</p>

Sub-endplate microcirculation disturbance directly contributes to intervertebral disc degeneration / 中华外科杂志

<p><b>OBJECTIVE</b>To build sub-endplate microcirculation disturbance animal model and to investigate the potential pathogenesis of intervertebral disc degeneration (IVDD).</p><p><b>METHODS</b>Twenty four New Zealand white rabbits were divided into treatment group (Group A) and control group (Group B). In Group A, animals received endotoxin and corticosteroid application to build sub-endplate microcirculation disturbance animal model, validated by microthrombus staining. In Group B, animals were given no drug, but standard feeding. After 3 month, the extent of IVDD was evaluated by the water content, biochemistry analysis, and morphology.</p><p><b>RESULTS</b>Sub-endplate microthrombus staining confirmed the exist of microcirculation disturbance. The water content and biochemistry components content of disc in Group A were lower than those of disc in Group B, and IVDD was observed in morphology.</p><p><b>CONCLUSION</b>Sub-endplate microcirculation disturbance can directly contribute to IVDD, the nutrients diffusion barrier is the potential pathogenesis of IVDD.</p>

Preliminary clinical outcomes of percutaneous kyphoplasty with Sky-bone expander / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Percutaneous kyphoplasty (PKP) using balloon expander has been proved to be effective in the treatment of painful vertebral compression fractures. Recently, Sky-bone expander, an alternative bone expander for PKP has been developed. The purpose of this study was to show our preliminary clinical outcomes of PKP with Sky-bone expander.</p><p><b>METHODS</b>PKP with Sky-bone expander was performed in 25 patients (30 vertebrae). The operation time, bleeding volume, cement volume injected were recorded. The pain and functional activities of the patients before and after the operation were compared using Wilcoxon signed-rank test. The cement distribution in the vertebrae, vertebral height restoration, and kyphosis correction after the procedure were evaluated by radiography. The pre- and post-operative absolute values of the vertebral height and kyphotic angle were compared by paired-sample t test. All the patients were followed up by telephone or clinic consulting after being discharged from our hospital.</p><p><b>RESULTS</b>The procedure was performed successfully in all the patients. Bipedicular injection was used in 2 of the patients, and unipedicular injection was made in the others. The operation time ranged from 25 to 120 minutes (45 minutes per vertebra on average). The average bleeding volume was about 20 ml. Polymethylmethacrylate 1.5-5.0 ml (mean, (3.15+/-0.78) ml) was injected through each pedicle into all the patients except one, who received calcium sulphate 3.5 ml instead. The patients were followed up for 12-15 months (13.5 months on average). The mean visual analogue scale (VAS) score, Oswestry Disability Index, anterior, midline, and posterior vertebral height, and kyphotic angle of the patients were improved significantly at the end of the follow-up compared with those before the operation. (2.5+/-1.3, 35.1%, (20.94+/-6.15) mm, (20.26+/-4.59) mm, (26.72+/-3.49) mm, and 8.2 degrees vs. 8.5+/-1.9, 61.2%, (19.11+/-6.72) mm, (15.88+/-5.73) mm, (25.78+/-3.67) mm, and 17.3 degrees; all P<0.05). The cement distribution with unipedicular injection was mostly limited within the injection site in the vertebral body. Cement extravasation was seen at ten levels (33.3%).</p><p><b>CONCLUSIONS</b>PKP with Sky-bone expander is an effective and relatively safe alternative to the PKP using balloon expander. It can relieve pain, improve physical function, and restore the height of the collapsed vertebrae, but the cement extravasation is unsolved.</p>

A comparison study of clinical application between balloon percutaneous kyphoplasty and "Sky-bone expander" percutaneous kyphoplasty / 中华外科杂志

<p><b>OBJECTIVE</b>To compare the clinical results of balloon percutaneous kyphoplasty (PKP) and "Sky-bone expander" PKP.</p><p><b>METHODS</b>From October 2004 to February 2006, 25 cases (57 vertebrae) balloon PKP and 24 cases (29 vertebrae) "Sky-bone expander" PKP procedures were performed. The operation time, bleeding volume, cement injected volume were recorded during operation. The patients' pain relief and functional activities recovery were evaluated after operation. The distribution of the cement and the restoration of vertebral height were also observed post-operation. All these patients were followed-up by telephone or clinic consults after discharged.</p><p><b>RESULTS</b>All cases were successfully experienced procedures. There are no significant differences in operative time, bleeding volume and cost of every vertebrae in these two group (P > 0.05). The balloon group had larger cement injected volume per pedicle than Sky group (4.27 +/- 1.08) ml vs. (3.15 +/- 0.78) ml (P < 0.05). The VAS and ODI scoring of these two groups were both decreased significantly after operation. The vertebral height were restored in both two groups with anterior height and midline height restored significantly in balloon group and midline height restored significantly in Sky group. The cement distribution of "Sky-bone expander" PKP with unipediclar injection mostly limited in the injective side of the vertebral body, but most of the balloon PKP vertebrae with unipediclar injection can be seen a cross-midline cement distribution in the anterior-posterior position X ray film.</p><p><b>CONCLUSIONS</b>Both balloon PKP and "Sky-bone expander" PKP are efficacious and safety in the treatment of vertebral compression fractures. "Sky-bone expander" PKP is more suitable for single level compressive fracture while balloon PKP is especially suitable for multiple level compressive fractures.</p>

Osteogenic induction of rabbit's bone marrow stromal cells and transfection of AAV-EGFP in vitro / 中华创伤骨科杂志

Objective To evaluate the effects of adeno-associated virus-enhanced green fluorescent protein (AAV-EGFP)on the biologic behavior of rabbit's bone marrow stromal cells(BMSCs)by means of a simple method of culturing and osteogenic induction in vitro so as to find an ideal viral vector and cell tracing mark for tissue en- gineering.Methods Total bone marrow culture was conducted to obtain rabbit BMSCs which were then induced in the osteogenic direction.The morphology of the cells was observed continuously,and their surface antigen and ossification were detected by alkali phosphatase stain and Von Kossa stain.On the basis of the above results, AAV-EGFP was transfected into the induced cells.The morphologic changes of the cells,the expression time and intensity of fluorescent light were observed.The transfection efficiency was detected to find the best multiplicity of infection(MOI)value.The cell growth curves were drawn to evaluate the biologic effects of AAV-EGFP on the cyto-activity.Results The morphology and purity of the rabbit BMSCs obtained were good.The ossification of the cells was significant after osteogenic induction.The best MOI value was found to be 1?10~5.The expression intensity of fluorescent light was strong with the expression time more than eight weeks so that the fluorescent light could be observed after cell generations.The transfection efficiency of AAV was high without significant biologic effects on the cyto-activity.Conclusions The total bone marrow culture and in vitro cell induction can satisfy the requirements for seeding cells in tissue engineering.AAV is an ideal viral vector for tissue engineering.Transfection of AAV-EGFP to cells could be an ideal method for cell tracing mark.