Zhi-Jun Hu

Zhejiang University, Hangzhou, Zhejiang Sheng, China

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Publications (8)8.76 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Multifidus muscle injury and atrophy are common after posterior lumbar spine surgery and are associated with low back pain and functional disability. In theory, muscle-splitting and retraction with a self-retaining retractor are considered to be the major surgical factors. The effects and mechanisms of retraction have been well studied, but the exact effect and possible mechanism of injury and atrophy after muscle-splitting still lack experimental evidence. New Zealand White rabbits were divided into two groups. In group S, through a skin and lumbodorsal fascial incision, the bilateral multifidus muscles were dissected from the osseous structures in the standard fashion, while in group C, only a skin and lumbodorsal fascial incision was made. In each group, the multifidus muscle was evaluated by magnetic resonance imaging (MRI) and by histological analysis at three and forty-eight hours and at one, three, six, twelve, and twenty-four weeks after surgery. In group C, there was no injury or atrophy of the multifidus muscle after surgery. In group S, the mean T2-weighted signal intensity ratios of gross multifidus to psoas on fat-suppressed T2-weighted cross-sectional MRI scans peaked on week 3 and returned to baseline on week 24. Necrosis and inflammation of the multifidus muscle were evident and became more severe at one week. Fibrotic change was mainly seen at three and six weeks after surgery, and fatty degeneration mainly occurred at twelve and twenty-four weeks. Decreased acetylcholine activity and granular degeneration of the neuromuscular junction were observed at all follow-up times, and the numbers of degenerating neuromuscular junctions increased significantly with time after surgery. The splitting approach is an important cause of multifidus muscle injury and atrophy in posterior lumbar spine surgery. Denervation and disuse may be important factors in multifidus muscle atrophy in the splitting approach. This study provides a basis for the prevention of multifidus muscle injury and atrophy after posterior lumbar surgery.
    The Journal of Bone and Joint Surgery 12/2013; 95(24):e1921-9. · 3.23 Impact Factor
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    ABSTRACT: To study differences of multifidus muscle injury between Wiltse intermuscular approach and intramuscular stripping approach in one-level small incision transforaminal lumbar interbody fusion (TLIF) surgery. A total of 46 patients with unilateral lumbar degenerative disease underwent small incision TLIF from August 2009 to February 2011 by one group of surgeons at a single institution. The decompression side of all patients adopted intra-muscular stripping approach; for the non-decompression side, 22 patients adopted Wiltse intermuscular approach (group A),and 24 patients adopted intra-muscular striping approach (group B). In group A, there were 13 males and 9 females, ranging in age from 36 to 74 years old,averaged 52.7 +/- 9.2; 1 patient had disease in L3, 4 12 in L4,5 and 9 in L5S1. In group B,there were 11 males and 13 females,ranging in age from 32 tio 72 years old, averaged 51.8 +/- 8.7; two patients had disease in L3,4, 14 in L4,5, and 8 in L5S1. The following data were compared between the 2 groups: surgical time from skin incision to completion of pedicle screw placement, suturation time, blood loss. Clinical effects were evaluated by VAS score pre-operatively, as well as 1, 6 and 12 months post-operatively. At the latest follow-up, all the patients were evaluated by MRI. This enabled the cross-sectional area (CSA) of lean multifidus muscle, and the T2 signal intensity ratio of multifidus to psoas muscle, to be compared at the operative level. There was no obvious difference in suturation time, but less surgical time from skin incision to completion of pedicle screw placement, less blood loss, less postoperative back pain in Wiltse intermuscular approach group. For the comparison between the two groups or paired comparison between sides in the Wiltse group, the reduction of lean CSA and increase in the multifidus:psoas T2 signal intensity ratio were all significant lower in Wiltse intermuscular approach group or side. The Wiltse intermuscular approach is an easy way for pedicle screw placement, and caused less paraspinal muscle damage than intra-muscular stripping approach, and had positive effects on less back pain.
    Zhongguo gu shang = China journal of orthopaedics and traumatology 09/2013; 26(9):735-40.
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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; · 0.18 Impact Factor
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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. · 2.13 Impact Factor
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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. · 2.16 Impact Factor
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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.
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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. · 1.05 Impact Factor
  • Bao-Jian Liu, Zhi-Jun Hu, Qi-Long Ren
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    ABSTRACT: The adsorption equilibria of single-component and binary mixtures of levulinic/formic acids in the aqueous solution on three different types of basic polymeric adsorbents were experimentally measured at 30 °C. Adsorption isotherms such as Langmuir, Freundlich and Sips were applied to correlate the single-solute adsorption data. Results demonstrated that the adsorption isotherms of both acids on all three adsorbents were best described by the Sips model, and that formic acid has higher adsorption capacity and stronger affinity on all three resins. The adsorption of binary mixtures of formic/levulinic acids reveals that formic acid is preferentially adsorbed and levulinic acid can be competitively displaced by formic acid. Binary Sips model and the ideal adsorbed solution (IAS) theory were employed to simulate the binary competitive adsorption data. The binary Sips model cannot predict the competitive adsorption behavior. The IAS model was successfully coupled with Sips isotherm parameters determined from single-component adsorption data to predict the binary competitive adsorption behavior of levulinic/formic acids on all three resins.
    Colloids and Surfaces A: Physicochemical and Engineering Aspects. 01/2009;

Publication Stats

14 Citations
484 Views
8.76 Total Impact Points

Institutions

  • 2009–2013
    • Zhejiang University
      • School of Medicine
      Hangzhou, Zhejiang Sheng, China
    • Zhejiang University of Science and Technology
      Hang-hsien, Zhejiang Sheng, China