The correlation between hypoxia-inducible factor-1α, matrix metalloproteinase-9 and functional recovery following chronic spinal cord compression.

The molecular mechanisms underlying cervical spondylotic myelopathy (CSM) are poorly understood. To assess the correlation between HIF-1α, MMP-9 and functional recovery following chronic cervical spinal cord compression (CSCI). Rats in the sham group underwent C5 semi-laminectomy, while a water-absorbable polyurethane polymer was implanted into the C6 epidural space in the chronic CSCI group. Basso, Beattie and Bresnahan score and somatosensory evoked potentials were used to evaluate neurological function. Hematoxylin and eosin staining was performed to assess pathological changes in the spinal cord, while immunohistochemical analysis was used to examine HIF-1α and MMP-9 expression on days 7, 28, 42 and 70 post-surgery. Normal rats were only used for HE staining. The BBB score was significantly reduced on day 28 following CSCI, while SEPs exhibited decreased amplitude and increased latency. In chronic CSCI group, the BBB score and SEPs significantly improved on day 70 compared with day 28. HE staining revealed different level of spinal cord edema after chronic CSCI. Compared with the sham group, immunohistochemical analyses revealed that HIF-1α- and MMP-9-positive cells were increased on day 7 and peaked on day 28. HIF-1α and MMP-9 expression were demonstrated to be significantly positively correlated, whereas HIF-1α expression and BBB score were significantly negatively correlated, as well MMP-9 expression and BBB score. HIF-1α and MMP-9 expression are increased following chronic spinal cord compression and are positively correlated with one another. Decreased expression of HIF-1α and MMP-9 may contribute to functional recovery following CSCI. This expression pattern of HIF-1α and MMP-9 may give a new perspective on the molecular mechanisms of CSM.

Surgical treatment indications and outcomes in patients with spinal metastases in the cervicothoracic junction (CTJ).

BACKGROUND: The cervicothoracic junction (CTJ) site accounts for approximately 10% of all spinal metastases. The complex anatomical and biomechanical features increase the difficulty in surgical treatment of the CTJ metastases. However, few studies in the literature on surgical treatment for spinal metastases are focusing on this special area. The aim of this study was to evaluate the surgical outcome of patients with CTJ metastases and analyze the prognostic factor for the postoperative survival. METHODS: Total of 34 patients with CTJ metastases who underwent surgery in our department were retrospectively analyzed. We evaluated records for the details of medical history, treatment, surgery, radiographic imaging, and follow-up. Outcomes were assessed by overall survival as well as modified Tokuhashi score, SINS, Frankel grade, visual analog scale (VAS), and Karnofsky Performance Status (KPS). RESULTS: The entire patients' median survival time was 12.4 months (range, 3.5-36.2 months). Pain improved in 32 patients (94.12%), and the postoperative VAS scores were significantly improved compared with preoperative data. Majority of patients (71%) maintained or improved their Frankel scores 1 year after surgery. KPS scores improved in 13 patients (38%), remained stable in 19 (56%), and worsened in 2 (6%) postoperatively. Notably, patients with neurological deficit that did not improve after surgery had significantly worse median survival than those who had either no deficit or who improved after surgery. There were no instrumentation failures in this study. CONCLUSIONS: Surgical treatment is effective for patients of CTJ metastases, with a tolerable rate of complications. Remained or regained ambulatory status predicted overall survival. Thus, prompt and aggressive decompressive surgery is recommended for CTJ metastases patients with neurological impairment.

The Safety and Efficiency of PVCR without Anterior Support Applied in Treatment of Yang Type A Severe Thoracic Kyphoscoliosis.

OBJECTIVE: To assess the clinical and radiographic outcomes of posterior vertebral column resection (PVCR) without anterior support in treatment of Yang type A severe rigid thoracic kyphoscoliosis. METHODS: The records of 27 Yang type A severe thoracic kyphoscoliosis patients treated with PVCR without anterior support from January 2010 to September 2013 were analyzed retrospectively. Intraoperative multimodal neurophysiological monitoring was conducted in all patients. The 6 modes were somatosensory evoked potential, motor evoked potential, descending neurogenic evoked potential, spinal cord evoked potential, and electromyography (both triggered and free run). Radiographic parameters and complications were used to evaluate the clinical outcomes. RESULTS: PVCR without anterior support was conducted successfully in all 27 patients. Intraoperative monitoring events occurred in 3 patients (3/27); of these, 1 patient (1/27) showed postoperative spinal cord injury, but completely recovered within 9 months after the operation (Frankel level E). The number and osteotomy space of vertebrae resection were mean 1.33 levels and 3.7 cm, respectively. All cases achieved good coronal and sagittal curve correction. No implant related complications occurred until the latest follow-up. The average follow-up was 40.1 months (range, 24-59 months). CONCLUSIONS: In this study, we found that posterior vertebral column resection (PVCR) without any anterior support with a mean 3.7 cm shortening of the spinal column is safe, if close and unyielding contact of end plates can be obtained. A comprehensive understanding of the technique and intensive intraoperative neuromonitoring is mandatory to perform these challenging and complex spine deformity correction procedures safely.

Convex-Rod Derotation Maneuver on Lenke Type I Adolescent Idiopathic Scoliosis.

BACKGROUND: Convex-rod derotation may have potential advantages for adolescent idiopathic scoliosis (AIS) correction; however, study of this technique has been limited. OBJECTIVE: To compare the radiographic outcomes of Lenke type I AIS patients treated by the convex- or concave-rod derotation maneuvers. METHODS: A retrospective study was designed to compare 2 cohorts, including 81 Lenke type I AIS patients treated with convex-rod derotation (n = 38) or concave-rod derotation (n = 43), between July 2008 and September 2012. All patients had complete clinical records and radiographic data, which were collected and compared between groups. RESULTS: In comparing 9 radiographic parameters, significant differences were found in the incidence of screw misplacement, the postoperative main-curve angle, and the corrective rate between groups. The major-curve angles in both the convex- and the concave-rod derotation groups were corrected from 54.0° ± 10.6° and 53.0° ± 11.1° preoperatively, to 8.5° ± 6.9° and 12.9° ± 6.8° postoperatively, with corrective rates of 85.3% and 76.0%, respectively (P = .001). Final T5-T12 kyphosis and appropriate coronal-to-sagittal balance were achieved in both groups. The incidence of screw misplacement in the convex and concave sides of all patients was 1.8% and 3.7%, respectively (P = .047), and 1.8% and 3.6%, respectively, in the convex- and the concave-rod derotation groups (P = .044). CONCLUSION: Compared with concave-rod derotation, convex-rod derotation can potentially improve the major-curve corrective rate and tends to reduce the risk of pedicle breach in Lenke type I AIS patients.

Ultrastructural Features of Neurovascular Units in a Rat Model of Chronic Compressive Spinal Cord Injury.

Chronic spinal cord compression is the most common cause of spinal cord impairment worldwide. Objective of this study is to assess the ultrastructural features of the neurovascular unit (NVU) in a rat model of chronic compressive spinal cord injury, 24 SD rats were divided into two groups: the control group (n = 12), and the compression group (n = 12). A C6 semi-laminectomy was performed in the control group, whereas a water-absorbent polyurethane polymer was implanted into the C6 epidural space in the compression group. The Basso Beattie Bresnahan (BBB) scores and the somatosensory evoked potentials (SEP) were used to evaluate neurological functions. Transmission Electron Microscopy (TEM) was performed to investigate the change of NVU at the 28th day after modeling. Compared with the control group, the compression group shows a significant reduction (P < 0.05) of BBB score and a significant severity (P < 0.05) of abnormal SEP. TEM results of the compression group showed a striking increase in endothelial caveolae and vacuoles; a number of small spaces in tight junctions; a significant increase in pericyte processing area and vessel coverage; an expansion of the basement membrane region; swollen astrocyte endfeet and mitochondria; and the degeneration of neurons and axons. Our study revealed that damage to NVU components occurred followed by chronic compressive spinal cord injury. Several compensatory changes characterized by thicker endothelium, expansive BM, increased pericyte processing area and vessel coverage were also observed.

The Precise Bending Rod Technique: A Novel Method for Precise Correction of Ankylosing Spondylitis Kyphosis.

STUDY DESIGN: To report a new technique. OBJECTIVE: To introduce a new method of precise correction controlling for ankylosing spondylitis kyphosis. SUMMARY OF BACKGROUND DATA: The exact angle method is excellent for calculating the pedicle subtraction osteotomy angle but is difficult to perform during surgery. In this study, the precise rod bending technique was proposed as a new method for precise correction controlling for ankylosing spondylitis kyphosis through illustrative cases. METHODS: A preoperative plan using the exact angle method, with exact osteotomy angle and level determined, was prepared using a whole-spine lateral x-ray film. Then a precise contoured rod imitating the predicted spine correction was obtained using the lateral spine x-ray film that was of the actual size of the trunk. This rod model was disinfected and used for precisely controlling kyphosis correction in ankylosing spondylitis patients with good cervical spine and hip joints. RESULTS: Four ankylosing spondylitis kyphosis patients were successfully corrected using the precise bending rod technique. Their mean age was 31 years, the mean operative time was 247 minutes (160-320 min), the mean volume of bleeding was 1482 mL (727-2700 mL), and the average follow-up period was 13.8 months (9-17 mo). All patients regained their sagittal balance (all C7-SSVL≤2 cm). The predicted ostetomy degree was accurate to within 2 degrees compared with the achieved degree at the osteotomy site. No complications occurred during or after surgery. CONCLUSIONS: The precise rod bending technique is a simple, effective method for precise correction of kyphosis caused by ankylosing spondylitis. The surgical result corresponded to the preoperative planning.

Vertebral Derotation by Vertebral Column Manipulator Improves Postoperative Radiographs Outcomes of Lenke 5C Patients for Follow-up of Minimum 2 Years.

STUDY DESIGN: This was a retrospective study. OBJECTIVE: The aim of this study was to compare radiographic outcomes of Lenke 5C adolescent idiopathic scoliosis (AIS) patients treated by vertebral column manipulator (VCM) or simple rod derotation (SRD) maneuver. SUMMARY OF BACKGROUND DATA: The direct vertebral rotation (DVR) technique has demonstrated better rotational and coronal correction than SRD, but clinical radiographic outcomes for Lenke 5C AIS following DVR using a VCM derotational device have not been described. MATERIALS AND METHODS: A retrospective study was carried out in 39 Lenke 5C AIS patients treated by VCM (n=20) or SRD (n=19) techniques between April 2008 and June 2011. All patients had complete clinical record and radiographic data. Nine radiographic variables were collected and compared at 3 time points (preoperative, immediate postoperative, and minimum 2-year follow-up) between both groups. RESULTS: Scoliosis was successfully corrected in both groups. All patients obtained good coronal and sagittal balance, and no severe complications occurred. The postoperative apical rotation corrective rate of the VCM and SRD groups were 55.1% and 25.5%, respectively (P < 0.05). Lowest instrumented vertebra and stable vertebra (LIV-SV) was statistically significant between the VCM and SRD groups, the mean values were 1.2 ± 0.4 level and 0.7 ± 0.5 level (P < 0.05). The main curve corrective rates and LIV-tilt angle correction rates were not significantly different between groups, but it showed a spontaneous correction for the coronal LIV-tilt angle for both groups at the last follow-up. CONCLUSIONS: VCM improved postoperative apical axial rotational correction and lessened the lumbar fusion segment compared with the SRD technique, which might have a potential trend to reserve lumbar mobility.

Comparison of unilateral versus bilateral percutaneous kyphoplasty for the treatment of patients with osteoporosis vertebral compression fracture (OVCF): a systematic review and meta-analysis.

PURPOSE: To compare the short- and long-term clinical outcomes, operation times, restoration rate, dosage of polymethylmeth-acrylate (PMMA) injected, complications and X-rays exposure frequency between unilateral and bilateral kyphoplasty approaches for the treatment of OVCF. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Randomized or non-randomized controlled trials published up to April 2015 that compared the unilateral and bilateral PKP for the treatment of OVCF were acquired by a comprehensive search in the Cochrane Controlled Trial Register, PubMed, MEDLINE, EMBASE, Web of Science, OVID. Exclusion criteria were patients with neoplastic etiology (metastasis or myeloma), infection, neural compression syndrome, invasive and degenerative disease, traumatic fracture, re-operation, neurological deficits, significant scoliosis and spinal stenosis. The main end points included: operation times, the short- and long-term postoperative Visual Analogue Scale (VAS) scores, the short-term postoperative Oswestry Disability Index (ODI), restoration rate, dosage of PMMA injected, cement leakage, X-ray exposure frequency and postoperative adjacent-level fractures. RESULTS: A total of 8 studies involving 428 patients were included in the meta-analysis. The mean operative time was shorter in the unilateral groups compared with the bilateral groups [P < 0.05, weighted mean difference (WMD) -19.74 (-30.56, -8.92)]. There was no significant difference in the short-term postoperative VAS scores [P > 0.05, WMD 0.03 (-0.34, 0.40)], the long-term postoperative VAS scores between them [P > 0.05, WMD 0.01 (-0.42, 0.45)] and the short-term postoperative ODI [P > 0.05, WMD -0.33 (-2.36, 1.69)] between the two groups. The unilateral approaches required significantly less dosage of PMMA than the bipedicular approaches did [P < 0.05, WMD -1.56 (-1.59, -1.16)]. The restoration rate in the bilateral groups was higher than the unilateral groups [P < 0.05, WMD -7.82 (-12.23, -3.41)]. There was no significant difference in the risk ratio of cement leakage [P > 0.05, RR 0.86 (0.36, 2.06)] and postoperative adjacent-level fractures [P > 0.05, RR 0.91 (0.25, 3.26)] between the two methods. The mean X-ray exposure frequency in the unilateral groups was greater than the bilateral groups [P < 0.05, WMD -5.69 (-10.67, -0.70)]. CONCLUSIONS: A definitive verdict could not be reached regarding which approach is better for the treatment of OVCF. Although unilateral PKP was associated with shorter operative time, less X- ray exposure frequency and dosage of PMMA than bilateral PKP. There was no apparent difference in the short- and long-term clinical outcomes and complications between them. However, bilateral PKP approaches were higher than unilateral PKP in term of the restoration rate. But on account of lack of some high-quality evidence, we hold that amounts of high-quality randomized controlled trials should be required and more complications should be analysed to resolve which surgical approach is better for the treatment of OVCF in the future.

A proposed classification system for guiding surgical strategy in cases of severe spinal deformity based on spinal cord function.

PURPOSE: Spinal cord function classification systems are not useful for guiding surgery in patients with severe spinal deformities. The aim of this study is to propose a classification system for determining a surgical strategy that minimizes the risk of neurological dysfunction in patients with severe spinal deformities. METHODS: The records of 89 patients with severe spinal deformities treated with vertebral column reconstruction from 2008 to 2013 were retrospectively analyzed. Based on neurophysiological monitoring, magnetic resonance imaging, and neurological symptoms patients were categorized into three groups: group A, normal spinal cord, normal evoked potentials and no neurological symptoms; group B, spinal cord abnormalities and/or abnormal evoked potentials but no neurological symptoms; group C, neurological symptoms with or without spinal cord abnormalities/abnormal evoked potentials. Outcomes and complications were compared between the groups. RESULTS: A total of 89 patients (51 male, 38 female) were included with 47 (52.8 %), 16 (18.0 %), and 26 (29.2 %) patients in groups A, B and C, respectively, and a mean follow-up 34.5 months. There were no differences in age, gender, average preoperative scoliosis, and kyphosis among three groups, but there were differences with respect to the causes of severe spinal deformity and the corrective rate of scoliosis and kyphosis. Changes in intraoperative evoked potentials were different in these three types according to this new classification, and the recovery rates of changes in the three groups were 71.1, 50.0, and 14.1 %, respectively. Postoperative spinal cord injury was positively related to intraoperative changes of evoked potentials. CONCLUSION: The classification system may be useful for guiding surgical decisions in patients with severe spinal deformities to minimize the risk of neurological complications.

Three-dimensional alteration of cervical anterior spinal artery and anterior radicular artery in rat model of chronic spinal cord compression by micro-CT.

OBJECTIVE: To investigate the spatial and temporal changes of anterior spinal artery (ASA) and anterior radicular artery (ARA) of chronic compressive spinal cord injury on rat model by three-dimensional micro-CT. METHODS: 48 rats were divided into two groups: sham control group (n=24) and compressive spinal cord injury group (n=24). A C6 semi-laminectomy was performed in the sham control group, while a water-absorbable polyurethane polymer was implanted into C6 epidural space in the compression group. The Basso Beattie Bresnahan (BBB) score and somatosensory evoked potentials (SEP) were used to evaluate neurological function. Micro-CT scanning was used to investigate the change of ASA and ARA after perfusion at the 1th (n=6), 28th (n=6), 42th (n=6) and 70th (n=6) day of post operation. The diameter, angle-off and vascular index (VI) was measured by 3D micro-CT. RESULTS: In comparison with sham control, BBB score have a significant reduction at the 28th day (p<0.05) and abnormal SEP have a significant severity at the 28th day (p<0.05). Both of them have a significant improvement at the 70th day compared with that of the 28th day (p<0.05). VI shows the amount of microvessels reduced at the 28th day (p<0.05) and increased at the 70th day (p<0.05). The diameter and angle-off of ASA and ARA also changed significantly at the 28th, 42th, 70th day (p<0.05). CONCLUSION: There was a significant alteration of cervical anterior spinal artery and anterior radicular artery after chronic cervical spinal cord compression. Alteration of ASA and ARA may affect the vascular density of spinal cord and play an important role in neural functional change of chronic cervical spinal cord compression through 3D micro-CT.

Role of hypoxia-induced VEGF in blood-spinal cord barrier disruption in chronic spinal cord injury.

Chronic spinal cord lesions (CSCL) which result in irreversible neurologic deficits remain one of the most devastating clinical problems. Its pathophysiological mechanism has not been fully clarified. As a crucial factor in the outcomes following traumatic spinal cord injury (SCI), the blood-spinal cord barrier (BSCB) disruption is considered as an important pathogenic factor contributing to the neurologic impairment in SCI. Vascular endothelial growth factor (VEGF) is a multirole element in the spinal cord vascular event. On one hand, VEGF administrations can result in rise of BSCB permeability in acute or sub-acute periods and even last for chronic process. On the other hand, VEGF is regarded to be correlated with angiogenesis, neurogenesis and improvement of locomotor ability. Hypoxia inducible factor-1 (HIF-1) is a primary regulator of VEGF during hypoxic conditions. Therefore, hypoxia-mediated up-regulation of VEGF may play multiple roles in the BSCB disruption and react on functional restoration of CSCL. The purpose of this article is to further explore the relationship among HIF-1, hypoxia-mediated VEGF and BSCB dysfunction, and investigate the roles of these elements on CSCL.

Comparison of the Wake-up Test and Combined TES-MEP and CSEP Monitoring in Spinal Surgery.

STUDY DESIGN: A retrospective clinical analysis. OBJECTIVE: The aim of this study was to compare the effectiveness of the wake-up test with that of combined monitoring of transcranial electrical stimulation motor evoked potentials (TES-MEP) and cortical somatosensory evoked potentials (CSEP) in spinal surgery. SUMMARY OF BACKGROUND DATA: TES-MEP/CSEP combined monitoring is being increasingly recognized as the ideal approach to detect spinal neurophysiological compromise during spinal surgery; however, as a result the merit of the wake-up test is now in doubt. MATERIALS AND METHODS: TES-MEP/CSEP combined monitoring was performed simultaneously in 426 patients who underwent spinal surgery at our department, and wake-up tests were conducted on 23 patients because of positive neurophysiological monitoring results with uncertain causes or persistent positive monitoring findings after all potential causes had been resolved. Preoperative and postoperative neurological examinations were performed as the gold standard to detect irreversible spinal function compromise. All data were collected to compare the efficiency of TES-MEP/CSEP combined monitoring with that of the wake-up test. RESULTS: Positive results of TES-MEP/CSEP combined monitoring were recorded in 64 cases. Among them, the positive monitoring findings agreed with the results of the neurological examination in 51 cases, and the monitoring results did not match that of neurological examination in 13 cases. No false-negative result was observed. The sensitivity of TES-MEP/CSEP monitoring was 100%, the specificity was 96.5%, and the Youden index was 0.965. Wake-up tests were conducted in 23 cases. In 8 patients the positive monitoring findings completely matched the postoperative neurological examination results. In contrast, in the other 15 cases with negative neurophysiological monitoring results, only 9 patients retained intact neurological function and 6 patients suffered compromised neurological function. The sensitivity of the wake-up test was 57.1%, the specificity was 100%, and the Youden index was 0.571. CONCLUSIONS: Combined TES-MEP and CSEP monitoring, with its high sensitivity and specificity, is an effective method for monitoring spinal function during surgery and should be the preferred choice. The wake-up test is a useful complementary method for monitoring because of its high specificity.

Double-curve synchronous derotation with convex correction: a new corrective technique for adolescent idiopathic scoliosis with double curves.

STUDY DESIGN: Report of a new technique. OBJECTIVE: We describe a new technique of double-curve synchronous derotation with convex correction for double-major adolescent idiopathic scoliosis (AIS) and is highlighted through illustrative cases. SUMMARY OF BACKGROUND DATA: Rotational deformity is a significant component of scoliosis, which causes a secondary rib hump, and adversely affects patients' psychological and social well-being, and long-term functional results. For AIS, direct vertebral rotation is confirmed as a better and effective method for apical rotational correction and rib hump improvement than rod rotation technique, avoiding the need for an adjuvant thoracoplasty. However, this technique is mainly applied to Lenke I type thoracic curves with derotation of the main curve. There are no reports applying this technique in double-major scoliosis. OPERATIVE TECHNIQUE: With the patient lying prone, a standard posterior incision exposure and segmental screws placement was performed, 2 vertebral column manipulator devices were installed on the apical region of both curves, then both curves were synchronously derotated and following convex correction at both the curves, the concave rods were secured in situ. RESULTS: There were 11 double-curve cases divided into 3 groups: double-curve derotation group (A group, 3 cases), single-curve derotation group (B group, 4 cases), and rod derotation group (C group, 4 cases); all cases had minimum 2-year follow-up. Three illustrative cases corrected by double-curve synchronous derotation with convex correction are presented with better apical rotational and correction in thoracic and lumbar curves than single-curve derotation and rod derotation cases. The mean apical derotational corrective rates were 95.3%, 46.7%, and 38.8% in the lumbar curve, 66%, -35.1%, and -38.9% in thoracic curve. The 3-dimensional correction was maintained at a minimum 2-year follow-up. CONCLUSIONS: Double-curve synchronous derotation with convex correction is a safe and effective technique for rotational and coronal correction in AIS with double curves, which can avoid apical rotation aggravation in minor curve induced by major curve derotaion.

Malignant transformation of benign intraosseous schwannoma in the cervical spine: a case report with an immunohistochemical study.

Although 3% to 30% of lesions in von Recklinghausen disease undergo malignant transformation, malignant transformation of benign solitary schwannoma is extremely rare. We reported a case of recurrence and malignant transformation in a benign intraosseous schwannoma arising in the cervical spine of a 44-year-old man. The patient presented giant tumor in the C3 vertebral body with aggressive, expansile, and osteolytic destruction and relapsed 2 years after surgical resection and spinal reconstruction. Clinical data, radiologic characteristics, surgical management, histopathologic and immunohistochemical features were noted in the duration of follow-up. The local recurrence, nuclear pleomorphism, epithelioid differentiation, a small number of positive S-100 protein-staining cells, and especially the high percentage of positive cells with p53 (80%) and Ki-67 (75%) proteins support the aggressive nature of the lesion in malignant transformation of benign intraosseous schwannoma in the cervical spine. Immunohistochemistry would be useful as an ancillary technique in diagnosis. It is our practice to suggest that such case has to be carefully resected and the patient followed up.

[Clinical evaluation of vacuum sealing drainage for treatment of deep infection after hip or knee replacement].

OBJECTIVE: To investigate the method and effectiveness of vacuum sealing drainage (VSD) combined with debridement for treatment of deep infection after hip or knee replacement. METHODS: Between September 2006 and May 2010, 13 cases of deep infection after joint replacement surgery were treated, including 5 males and 8 females with an average age of 62.5 years (range, 56-78 years). Infection occurred at 7 days to 1 year and 2 months (median, 14 days) after joint replacement surgery. The time from infection to admission was 8 days to 4 years and 6 months (median, 21 days). Purulent secretion with or without blood were observed in all patients; sinus formed in 5 cases; and unhealing of incision or drainage opening disunion were observed in 8 cases. The size of skin defect at secretion drainage or sinus opening site was 5 mm x 3 mm to 36 mm x 6 mm; the depth of drainage tunnel or sinus was 21-60 mm. The histopathological examination in 11 patients showed acute infection or chronic infection with acute onset in 10 cases, and tuberculosis in 1 case. In 6 cases of secretion culture, Staphylococcus aureus was isolated from 5 cases. After thorough debridement, wound irrigation was performed during the day and VSD during the night in 10 cases. VSD was merely performed in 3 cases. RESULTS: In 1 case after revision total hip arthroplasty, the wound bled profusely with VSD, then VSD stopped and associated with compression bandage, VSD proceeded again 3 days later with no heavy bleeding. All the patient were followed up 1 year to 4 years and 5 months (mean, 2 years and 11 months). Infection were controlled 7-75 days (mean, 43 days) after VSD in 10 cases. In these cases, prosthesis were reserved, no recurrent infection was observed, wound were healed, limb function were reserved. VSD was refused in 1 case because of hypersensitive of the pain at the vacuum site, infection control was failed and amputation at the thigh was proceeded. The effect was not evident in 1 case with tuberculosis infection, then the prosthesis was removed and arthrodesis was proceeded followed by complete union. In 1 case, infection was cured with VSD, recurrent infection happened after 9 months, antibiotic-impregnated cement spacer was used at end, and no recurrence was observed 1 year and 4 months later. CONCLUSION: VSD combined with debridement can drainage deep infection sufficiently, promote wound healing, reduce recurrent infection rate, maximize the possibility of prosthesis preservation.

[Evaluation of the role of combined TES-MEP and CSEP monitoring during the spinal surgery].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Experimental study on spinal fusion induced by hBMP-4 gene modified tissue engineered bone].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Two kinds of posterior approach for Kvmmell's disease after osteoporotic thoracolumbar fracture.

OBJECTIVE: To compare the surgical results of two kinds of posterior approach for osteoporotic thoracolumbar Kvmmell's disease. METHODS: Clinical and radiographic results of 1-segmental pedicle screw fixation combined with vertebroplasty (Group A, n equal to 12) or posterior shortening osteotomy (Group B, n equal to 16) for osteoporotic thoracolumbar Kvmmell's disease were analyzed retrospectively. Japanese orthopedic association (JOA) and visual analogue scale (VAS) scores were used for clinical evaluation. Neurological status was judged by Frankel grades. X-ray was used to evaluate the radiographic results. Complications related to operation and devices were also considered. RESULTS: The follow-up period was 12-54 months (average 29 months). Pre-and post-operative VAS were 9.3 and 3.2 in Group A, 8.9 and 2.5 in Group B, respectively. The mean JOA score at the final follow-up was significantly higher than that of pre-operation (t equal to 5.306, P less than 0.001). There was no significant difference between Groups A and B (t equal to 0.618, P larger than 0.05). The kyphosis were corrected from preoperative 33.9 degree A)/37.3 degree B) to postoperative 10.3 degree A)/6.5 degree B), and 15.3 degree (A)/13.7 degree B) at the final follow-up. There was a significant difference between the two groups at the final follow-up. Frankel grade was improved from grade C preoperatively to postoperatively grade D or E in 7 cases of Group A and 5 cases of Group B, from grade D to E in 5 cases of Group A and 11 cases of Group B. The mean improvement was 1.6 and 1.7 grades for Groups A and B, respectively. There were no serious complications related to internal fixation. CONCLUSIONS: The similar clinical results can be obtained by the two kinds of posterior surgical methods for osteoporotic Kvmmell's disease. Posterior spinal shortening is a better choice for patients with serious kyphosis combined with neurological deficit than the other.

[Effect of total flavone of Epimedium on expression of bone OPG, OPGL mRNA in ovariectomized rats].

OBJECTIVE: To investigate the molecular mechanism of TFE (total flavone of epimedium) in the treatment of osteoporosis, and then provide experimental evidence for modernization and further development of TFE as an traditional Chinese medicine. METHODS: Sixty healthy female SD rats with aged 4 months were randomly divided into three groups (including control group in which rats received sham surgery, OVX group in which ovariectomized rats didn't give any medicine after the removal of ovaries and TFE group in which ovariectomized rats administrated TFE), 20 rats in each group. Compared bone mineral density (BMD) between before operation and at 4th week after operation in order to verify the establishment of osteoporotic model (criteria: BMD decreased more than 20% at 4th week after operation). The rats in TEF group were administrated total flavone of epimedium(concentration 30 mg/ml, 10 ml/kg, qd) orally for 4 weeks. After this, killed rats to harvest the lower part of the femur and detected BMD again. Applying the reverse transcriptase-polymerase chain reaction technique (RT-PCR) to detect expression of OPG, OPGL mRNA in bone tissue. RESULTS: (1) At 4th week after ovariectomy, the mean BMD of lumbar vertebra in TFE group fell to (0.084 +/- 0.020) g/cm2. Administrated with TFE for 4 weeks,the BMD increased to (0.112 +/- 0.009) g/cm2. There was significant improvement compare with the OVX group (P < 0.05). (2) Compared between OVX group and TFE group, The OPG mRNA expression of TFE group obviously enhanced. There was significant difference in statistics (P < 0.05). However,the promotion for OPGL mRNA expression were detected between OVX group and TFE group,there was no significant difference in statistics (P > 0.05). CONCLUSION: This study showed that TFE could inhibit differentiation and maturation of osteoclast through enhancing OPG mRNA expression, accordingly,to treat osteoporosis.

Primary non-Hodgkin's lymphoma of the spine with neurologic compression treated by radiotherapy and chemotherapy alone or combined with surgical decompression.

Neurologic compression is a disastrous consequence for the patients with primary non-Hodgkin's lymphoma (NHL) of the spine, and such a condition has not been carefully taken into account in the treatment guidelines. The aim of this study was to compare the effect of radiotherapy and chemotherapy alone or combined with surgical decompression on primary NHL of the spine with neurologic compression. Sixteen patients with primary NHL in the vertebrae of the spine were treated between 1994 and 2006. Thirteen patients had neurologic compression. The neurologic deficits in 11 patients involved soft tissue extension from the vertebral tumors and 3 had vertebral fractures with motor signs and 5 had radicular pain. Five patients were treated by radiotherapy and chemotherapy alone while 8 were combined with surgical decompression. The decompression operation for tumors resulted in neurologic recovery in 6 patients. Five patients were not operated on but three received emergent radiotherapy before chemotherapy, 4 of whom had complete recovery in their neurologic symptoms. Of all patients, 3 relapsed. At average follow-up of 61.5 months (range 2-156 months), 4 patients had died after an average interval of 23.3 months from treatment (range 3-71 months). The 5-year overall survival rate was 82% with 60% for the patients in the surgical group, 100% for the patients in the non-surgical group. There was no difference between the groups (chi(2)=3.559, P=0.059). The 5-year overall survival was 100% for the 8 patients who completed CHOP chemotherapy and radiotherapy. It appears that optimum treatment in these patients depends on the cause of the neurologic deficits, whereas the survival is not influenced by the surgical or non-surgical treatment. The results suggest that chemotherapy and radiotherapy alone is the ideal treatment for these patients whose neurologic compression was only due to soft tissue extension. The authors emphasize the importance of chemotherapy and radiotherapy followed by surgical decompression depending on individual priorities in the indications for operation on primary NHL of spine with neurologic compression.