Zhi-Jun Hu

Zhejiang University, Hangzhou, Zhejiang Sheng, China

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Publications (10)7.61 Total impact

  • Article: Iatrogenic injury to the erector spinae during posterior lumbar spine surgery: underlying anatomical considerations, preventable root causes, and surgical tips and tricks.
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    ABSTRACT: The approach-related morbidity resulting from iatrogenic erector spinae injury in posterior lumbar surgery has become an increasing concern for spine surgeons. Many studies have explained the injury mechanisms and reported new surgical approaches to prevent this iatrogenic injury from their own point of views, but there is still no systemic information for a thorough understanding of this iatrogenic erector spinae injury that may give spine surgeons practical advices in their individual operations. We consequently reviewed the literature on the anatomy of erector spinae, causes of injury, and relative minimally invasive approaches. We found that the local anatomic structures make the erector spinae vulnerable to injury during posterior lumbar surgery, especially the medial multifidus which is innervated only by the medial branch of the dorsal ramus, with no intersegmental nerve supply as in the other paraspinal muscles, and the injury factors mainly include dissection, retraction, denervation, and immobility. Studies suggest that the goal of prevention is to preserve the physiological structure of erector spinae and to avoid or limit the injury causes: approaches through spatium intermusculare and approaches with endoscope and tubular retractor system can prevent the erector spinae from injury by less dissection and retraction; non-fusion techniques may prevent the erector spinae from disuse atrophy by preserving the segmental motion and the adjacent erector spinae activity.
    European Journal of Orthopaedic Surgery & Traumatology 02/2013; · 0.10 Impact Factor
  • Article: Quantitative MRI analysis of the surface area, signal intensity and MRI index of the central bright area for the evaluation of early adjacent disc degeneration after lumbar fusion.
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    ABSTRACT: The aim of this study was to evaluate early ASD at short-term follow-up in fused and unoperated patients with degenerative disc disease, using quantitative magnetic resonance imaging (MRI) analysis of the area, signal intensity and their product, i.e., MRI index of the central bright area of the disc as well as measures of intervertebral disc height and Pfirrmann grading scale. The further purpose was to determine whether fusion accelerates ASD compared with non-surgical treatment in short-term follow-up. One hundred and eight chronic low back patients diagnosed as L4/L5 degeneration undertook either one-level instrumented posterior lumbar interbody fusion or conservative treatment. They were followed up for about 1 year. Finally 46 fused and 45 conservatively treated patients with MRI follow-up were included. Pre- and post-treatment MRIs were compared to determine the progression of disc degeneration at the two cranial adjacent segments. The area, signal intensity and MRI index of the central bright area of the adjacent discs decreased in the operated and unoperated groups from pre-treatment to follow-up, except for an insignificant decrease of signal intensity at the second adjacent segment in the unoperated group. The changes in these parameters were statistically greater at the first than the second adjacent segment in the fused group, but not in the unoperated group. And the changes in the fused group were more pronounced than those at both neighbouring levels in the unoperated group. However, the Pfirrmann grading scale and intervertebral disc height did not detect any changes at adjacent discs in either group. Decrease in the parameters of quantitative MRI analysis indicated early degeneration at discs adjacent to lumbar spinal fusion. Fusion had an independent effect on the natural history of ASD during short-term follow-up. Continued longitudinal follow-up is required to determine whether these MRI changes lead to pathologic changes.
    European Spine Journal 04/2012; 21(9):1709-15. · 1.97 Impact Factor
  • Article: An assessment of the intra- and inter-reliability of the lumbar paraspinal muscle parameters using CT scan and magnetic resonance imaging.
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    ABSTRACT: A reliability study was conducted. To estimate the intra- and intermeasurement errors in the measurements of functional cross-sectional area (FCSA), density, and T2 signal intensity of paraspinal muscles using computed tomography (CT) scan and magnetic resonance imaging (MRI). CT scan and MRI had been used widely to measure the cross-sectional area and degeneration of the back muscles in spine and muscle research. But there is still no systemic study to analyze the reliability of these measurements. This study measured the FCSA and fatty infiltration (density on CT scan and T2 signal intensity on MRI) of the paraspinal muscles at L3-L4, L4-L5, and L5-S1 in 29 patients with chronic low back pain. Two experienced musculoskeletal radiologists and one superior spine surgeon traced the region of interest twice within 3 weeks for measurement of the intra- and interobserver reliability. The intraclass correlation coefficients (ICCs) of the intra-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. The ICCs of the inter-reliability ranged from fair to excellent for FCSA, and good to excellent for fatty infiltration. There were no significant differences between CT scan and MRI in reliability results, except in the relative standard error of fatty infiltration measurement. The ICCs of the FCSA measurement between CT scan and MRI ranged from poor to good. The reliabilities of the CT scan and MRI for measuring the FCSA and fatty infiltration of the atrophied lumbar paraspinal muscles were acceptable. It was reliable for using uniform one image method for a single paraspinal muscle evaluation study. And the authors preferred to advise the MRI other than CT scan for paraspinal muscles measurements of FCSA and fatty infiltration.
    Spine 01/2011; 36(13):E868-74. · 2.08 Impact Factor
  • Article: Comparison of paraspinal muscle injury in one-level lumbar posterior inter-body fusion: modified minimally invasive and traditional open approaches.
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    ABSTRACT: To determine differences in paraspinal muscle injury between a modified minimally invasive approach (MMIA) and a traditional operative approach (TOPA) for one-level instrumented posterior lumbar inter-body fusion (PLIF). From March 2006 to May 2008, a consecutive series of 91 patients who underwent a one-level instrumented PLIF procedure using one of two different approaches (MMIA in 41 patients and TOPA in 50), and who were operated on by one group of surgeons at a single institution, was studied. The following data were compared between the two groups: surgical time, blood loss, and changes in postoperative serum concentration of creatinine kinase (CK). More than 1 year post operation, low back pain was evaluated by a visual analog scale (VAS) and the Oswestry disability index (ODI). Some patients were also evaluated by MRI to allow comparison of the preoperative and postoperative cross sectional area (CSA) and fat degeneration grades at the operative level. There was no statistically significant difference in surgical time, but blood loss, serum concentration of CK, and scores of the VAS and ODI were markedly less in the MMIA group compared with the TOPA group. In the TOPA group, the postoperative CSA of the multifidus muscles was significantly smaller than it was pre-operatively. In contrast, there was no significant difference between the pre- and post-operative CSA of the multifidus muscles in the MMIA group. There was more fatty infiltration postoperatively than preoperatively in both the TOPA and MMIA groups, the increase in fatty infiltration being greater in the TOPA than in the MMIA group. Compared with TOPA, MMIA can significantly lessen paraspinal muscle injury, and reduce the incidence of low back pain.
    Orthopaedic Surgery 08/2010; 2(3):194-200.
  • Article: Modic changes, possible causes and promotion to lumbar intervertebral disc degeneration.
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    ABSTRACT: Modic changes are bone marrow and endplate lesions visible in magnetic resonance imaging (MRI). They are regarded as a part of degenerative disc disease and associated with low back pain. And severe disc degeneration was occurred more in the patients with Modic changes. But there is still no study to analyze the relationship between Modic changes and intervertebral disc degeneration. We hypothesize that Modic changes are the possible causes and promotion of lumbar intervertebral disc degeneration. And there are three possible mechanisms for this hypothesis: a structural cause: Modic changes make cartilaginous material easier in extruded disc herniations, to destroy the structure of intervertebral disc and inhibit the absorption of the disc. A biomechanical cause: Modic changes alter the mechanical loading distribution on disc, to initiate a series of disc disruption and inhibit the self-recovery of the disc. A nutritional cause: Modic changes destroy the vascular architecture in vertebral endplate and block the most important metabolism pathway between vertebrae and disc. Perspectives: (1) Find out procedures to cure Modic changes may be an important breakthrough for disc degenerative disease. (2) Treatment of Modic changes may be a critical step of biotherapy for disc degeneration disease.
    Medical Hypotheses 08/2009; 73(6):930-2. · 1.39 Impact Factor
  • Article: [An update of repairing spinal cord injury by olfactory ensheathing cells].
    Zhi-jun Hu, Ying-hui Ma
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    ABSTRACT: The treatment of spinal cord injury is always a stubborn problem for neurosurgeons because nerve cell cannot regenerate and the glia scar can prevent the axonal regeneration. Olfactory ensheathing cells (OECs) is a kind of especial glia cell, which possesses the character of horizontal cell of central nervous system and schwann cell. Many foundational and clinical studies showed that the olfactory ensheathing cellscan promote axonal regeneration and prove axonal growth, some progress is made and this is bringing hope for treatment of spine injury.
    Zhongguo gu shang = China journal of orthopaedics and traumatology 02/2009; 22(1):68-71.
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    Article: [Study of Yiqi Huayu Bushen recipe and its decomposed formulas in regulating gene expressions in degenerated cervical intervertebral discs of rats].
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    ABSTRACT: To investigate the gene expression changes in the degenerated cervical intervertebral discs of rats, and to study the function of Yiqi Huayu Bushen Recipe, a compound Chinese herbal medicine, and its discomposed formulas in regulating gene expressions in the degenerated cervical intervertebral discs. The rat model with degenerated cervical intervertebral discs caused by imbalance between the dynamic and static forces was established. The mRNA was extracted from the cervical intervertebral discs of rats in the normal control and experiment groups, and the cDNA probes were obtained by inverse transcript. The cDNA probes were hybridized with the gene chips. The gene expression pattern was gained with a laser scanner. Image analysis, standardized ratio value and cluster analysis were used to investigate the differential of gene expressions between the control and experiment groups. Cluster analysis showed that the gene chips of No.1 (Yiqi Huayu group), No.2 (Yiqi Bushen group) and No.3 (Huayu Bushen group) were in one class, while the gene chips of No.4 (untreated group) and No.5 (Yiqi Huayu Bushen group) were in the other. The gene expression of No.4 was different from the others mostly, and the gene expressions of No.2 and No.3 were similar. There were 96 genes expressed differently in three cases and among them 77 genes were already known and the expression of 48 genes were up-regulated (ratio>1.0), and 29 down-regulated (ratio<0.5). There were 25 genes expressed differently between the untreated group and the herb-treated groups. The gene expressions of the degenerated rat intervertebral discs are changed. Yiqi Huayu Bushen Recipe and its discomposed formulas have the effect of regulating the expressions of related genes, such as PI(3)K, PTK, ERK3, and PH1B1.
    Journal of Chinese Integrative Medicine 12/2006; 4(6):615-9.
  • Article: Cervical intervertebral disc degeneration induced by unbalanced dynamic and static forces: a novel in vivo rat model.
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    ABSTRACT: Establishment of a novel in vivo animal model of cervical spondylosis. To investigate apoptotic, degenerative, and inflammatory changes occurring in the cervical intervertebral discs of rats. Cervical degeneration occurs as the result of imbalance of both static and dynamic spinal stabilizers. The disc degeneration that occurs is characterized by increased local inflammation and increased apoptosis of intervertebral disc cells. By excising the paraspinal musculature and posterior cervical spinal ligaments of rats, both static and dynamic cervical stabilizers were disrupted. The resultant biomechanical imbalance resulted in biochemical and histologic changes, which were characterized by light microscopy, electron microscopy, immunostaining, enzyme-linked immunosorbent assay, polymerase chain reaction, and in situ hybridization. Histologic analysis showed characteristic degenerative changes of the intervertebral discs and vertebral endplates following surgery. Ultrastructural examination revealed apoptotic changes, which were verified by immunostaining. Instability also resulted in significant up-regulation of inflammatory factors, as shown by enzyme-linked immunosorbent assay, polymerase chain reaction, and in situ hybridization. By creating static and dynamic posterior instability of the cervical spine, this novel model of cervical spondylosis results in rapid intervertebral disc degeneration characterized by increased apoptosis and local inflammation, such as that seen clinically.
    Spine 07/2006; 31(14):1532-8. · 2.08 Impact Factor
  • Article: [Effects of yiqi huayu recipe and its decomposed formulas on apoptosis-related factors of anulus fibrosus cells in rats].
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    ABSTRACT: To study the effects of Yiqi Huayu Recipe and its decomposed formulas-medicated sera on expressions of bcl-2, Bax and caspase-8 of apoptotic anulus fibrosus cells in rats. Immunohistochemical and integral optical density analytic methods were used to observe the effects of Yiqi Huayu Recipe-, Yiqi Recipe-, Huayu Recipe-medicated sera and insulin-like growth factor 1 (IGF-1) on the expressions of bcl-2, Bax and caspase-8 of apoptotic anulus fibrosus cells in rats induced by anti-Fas antibody. As compared with apoptosis group, bcl-2 expression was higher, Bax and caspase-8 expressions were lower in Yiqi Huayu-treated, Yiqi-treated, Huayu-treated and IGF-1 groups (P<0.01). As compared with Yiqi-treated group and Huayu-treated group, Bax expression was lower in Yiqi Huayu-treated group (P<0.05). Yiqi Huayu Recipe and its decomposed formulas can delay degeneration of the cervical intervertebral disc, which may be due to its action in regulating the expressions of bcl-2, Bax and caspase-8.
    Journal of Chinese Integrative Medicine 12/2005; 3(6):466-9.
  • Article: [Effects of Yiqi Huayu Recipe on gene expression pattern of normal and apoptotic chondrocytes in cervical intervertebral disc in rats].
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    ABSTRACT: To study the effects of Yiqi Huayu Recipe on the gene expression pattern in normal and apoptotic chondrocytes in the cervical intervertebral disc of rats. The intervertebral disc endplates of rats were digested enzymatically. The apoptosis of the chondrocytes was induced by anti-Fas antibody. BiostarR-40s microarray chips were used to investigate the gene expression pattern in chondrocytes in the normal control, apoptosis and Yiqi Huayu Recipe groups. The results were scanned with Scan Array 4000 and analyzed with GenePix Pro 3.0, and then subjected to standardization and ratio analysis. In the apoptosis group, 30 kinds of genes expressed in cervical intervertebral disc chondrocytes were screened out, in which 10 were up-regulated (ratio>2) and 20 down-regulated (ratio<0.5) as compared with the normal control group. On the other hand, in the Yiqi Huayu Recipe group, 97 kinds of genes expressed in cervical intervertebral disc chondrocytes were screened out, in which 44 were up-regulated (ratio>2) and 53 down-regulated (ratio<0.5) as compared with the apoptosis group. There are some signal transduction pathways that control the apoptosis of the intervertebral disc chondrocytes. Yiqi Huayu Recipe regulates the gene express of the apoptotic chondrocytes in intervertebral disc. The study gives a further understanding to the mechanism of the cervical spondylosis and enriches the theories of qi and blood of traditional Chinese medicine.
    Journal of Chinese Integrative Medicine 03/2005; 3(2):111-4.