Analysis of posterior lumbar interbody fusion (PLIF) in treating lumbar degenerative disease in elderly patients / 中国骨伤

<p><b>OBJECTIVE</b>To explore the clinical effects of PLIF surgery for elderly patients with lumbar degenerative disease.</p><p><b>METHODS</b>From March 2010 to May 2013, 28 patients with lumbar degenerative disease, aged more than 80 years were treated with PLIF surgery. There were 10 males and 18 females, aged from 80 to 93 years old with an average of (85.44±3.66) years. Course of disease was from 3 to 20 years. The operation time, intra-operative blood loss, operation complications were recorded and JOA scores and Macnab criteria were used to evaluate the clinical outcomes.</p><p><b>RESULTS</b>All patients were followed up from 12 to 40 months with an average of 26.5 months. The average operation time was (150.00±26.42) min and the average intra-operative blood loss was (373.33±99.88) ml. The pre-operative JOA score was 12.30±2.43, and the corresponding postoperative JOA score at the final follow-up was 24.81±2.09 which was much higher than the preoperative one (P<0.01). According to the modified Macnab criteria to evaluate at the final follow-up, 16 patients got an excellent result, 10 good, 2 fair. In the weeks postoperatively, injuries of nerve root happened in 3 cases, superficial wound infection with delayed healing in 3 cases, and tear of the dural sac accompanied with cerebrospinal fluid leakage in 1 case. After long term follow-up, adjacent segment degeneration and the corresponding spinal canal stenosis occurred in 1 case at 34 months after operation. All cases got successful fusion without any displacement of internal fixation and pseudoarthrosis formation.</p><p><b>CONCLUSION</b>With proper cases, fully preoperative preparation, perfect intra-operative manipulation and active treatment after operation, even advanced ages older than 80 years with lumbar degenerative disease could get satisfactory outcomes after PLIF surgery.</p>

Surgical revision of lumbar vertebrae using transforaminal endoscopic spine system / 中国骨伤

<p><b>OBJECTIVE</b>To explore the clinical effects of transforaminal endoscopic spine system in surgical revision of lumbar vertebrae.</p><p><b>METHODS</b>From January 2012 to October 2013,14 patients who needed reoperations of lumbar vertebrae were treated using transforaminal endoscopic spine system (TESSYS). There were 8 males and 6 males, aged from 27 to 84 years old with an average of (50.4 ± 18.9) years. Visual analogue scale (VAS) and Japanese Orthopaedic Association Scores (JOA) were compared before and after surgical revision. Macnab standard was used to assess the clinical effect.</p><p><b>RESULTS</b>All the patients were followed up from 6 to 27 months with the mean of 18 months. Preoperative VAS score was 6.79 ± 1.31, and in a week,3 months and 6 months after operation were 2.50 ± 1.29, 2.21 ± 1.53, 1.64 ± 1.08, respectively, which were all much lower (P < 0.01) than preoperative score. Preoperative JOA score was 12.43 ± 1.95, and the above corresponding postoperative JOA scores were 21.50 ± 3.78, 21.93 ± 4.55, 23.36 ± 4.33, respectively, which were all much higher than preoperative score (P < 0.01). According to the modified Macnab criteria, 5 patients got an excellent results, 7 good, 1 fair and 1 poor. The nerve root injury of L5 occurred in 1 case during paracentesis and no other complications were found.</p><p><b>CONCLUSION</b>Selecting the appropriate indications using TESSYS in surgical revision of lumbar vertebrae can successfully avoid the operation scar, reduce the surgical complications and obtain satisfactory clinical outcomes.</p>

Additional screws fixation on fractured vertebrae versus only short-segment posterior instrumentation for thoracolumbar A3 fracture without neurologic deficit / 中华外科杂志

<p><b>OBJECTIVE</b>To compare the clinical results of additional screws fixation on fractured vertebrae versus only short-segment posterior transpedicular instrumentation for A3 thoracolumbar fracture without neurologic deficit.</p><p><b>METHODS</b>Clinical data of 52 cases of thoracolumbar burst fracture without neurologic deficit were retrospectively analyzed. All patients were divided into 2 groups due to different instrumentation and all fractures were classified as type A3 according to AO Classification.From January 2005 to December 2006, 23 cases in group A were treated by short-segment posterior instrumentation combined with additional screws fixation on fractured vertebrae. There were 18 male and 5 female with a mean age of (35.3+/-8.3) years. The fracture segment included 1 in T11, 9 in T12, 11 in L1 and 2 in L2. From January 1999 to December 2004, 29 cases in group B were treated only by conventional short-segment posterior transpedicular instrumentation. There were 20 male and 9 female with a mean age of (37.3+/-6.8) years. The fracture segment included 1 in T11, 7 in T12, 20 in L1 and 1 in L2. The clinical effect and radiographic measurements were respectively compared preoperatively, immediate and 2 years postoperatively.</p><p><b>RESULTS</b>All patients were followed up and the mean follow-up time was (37.4+/-10.9) months (from 24 to 48 months). There was no statistic difference of mean JOA and VAS score between 2 groups preoperatively, immediate and 2 years postoperatively (P>0.05). The average immediate postoperative correction of Cobb's angle was 13.7 degrees+/-7.7 degrees in group A, which was statistically significantly higher than that of 8.8 degrees+/-5.0 degrees in group B (P<0.01). The mean kyphosis correction loss of 2.9 degrees+/-1.5 degrees in group A was statistically significantly lower than that of 5.0 degrees+/-2.9 degrees in group B 2 years postoperatively (P<0.01). The average restoration of anterior height of fractured vertebral body immediate postoperatively was (29.4+/-6.0)% and (21.7+/-6.9)% respectively. The mean correction loss of anterior height 2 years postoperatively was (3.1+/-0.8)% and (6.6+/-3.0)% respectively. The average restoration of posterior height of fractured vertebral body immediate postoperatively was (8.5+/-3.2)% and (6.1+/-1.8)% respectively. The mean correction loss of posterior height 2 years postoperatively was (2.0+/-0.8)% and (3.4+/-1.0)% respectively. There were significant differences in average restoration of anterior/posterior height immediate postoperatively and correction loss of anterior/posterior height 2 years postoperatively between the 2 groups (P<0.01). According to fracture fragments protruded into the spinal canal on immediate postoperative CT image, there were complete reduction in 11 cases (47.8%) and partial reduction in 12 cases (52.2%) in group A, which was statistically significantly better than those in group B (P<0.01). There was no severe neurologic complications and no other complications related to additional screws fixation postoperatively. Pedicle screw breakage occurred in 2 cases in group B and none in group A.</p><p><b>CONCLUSIONS</b>Better initial kyphosis correction and less loss of correction 2 years after operation can be obtained by using additional screws fixation on fractured vertebra for thoracolumbar A3 fracture without neurologic deficit.</p>

Concurrent arthroscopic bicruciate ligament reconstruction using Achilles tendon-bone allografts: experience with 15 cases / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the clinical outcome of arthroscopically assisted combined anterior and posterior cruciate ligament (ACL/PCL) reconstructions using Achilles tendon-bone allografts.</p><p><b>METHODS</b>Associated meniscus injuries were treated according to established methods prior to ligament reconstructions during arthroscopic surgery. Thirty Achilles tendon-bone allografts were used to reconstruct torn ACL and PCL in 15 knees. At postoperative follow-up, all knees were graded using the modified IKDC and the Lysholm scoring systems just as done preoperatively.</p><p><b>RESULTS</b>were analyzed compared with the contralateral healthy knees. Results: Eleven men and 4 women with a minimum of 3-year follow-up (mean 38 months) were included in the study. Preoperatively, the group ratings by the modified IKDC standards were all severely abnormal. Twelve bicruciate reconstructions were performed in subacute or chronic stage (larger than 3-8 weeks), 3 for acute ligamentous deficiencies (less than or equal to 3 weeks). The noticeable early complication was transitory local fever combined with joint effusion in one case. At postoperative follow-up, 9 knees were normal, 5 nearly normal and 1 abnormal. On Lysholm score the difference was statistically significant (t- test, P less than 0.001) before and after operation.</p><p><b>CONCLUSIONS</b>Achilles tendon-bone allograft offers an alternative for simultaneous arthroscopic ACL/PCL reconstructions. However, further investigation is needed to eradicate its potential immunogenicity for better use.</p>

Calpain activation and secretion promote glomerular injury in experimental glomerulonephritis: evidence from calpastatin-transgenic mice.

Glomerular injury and albuminuria in acute glomerulonephritis are related to the severity of inflammatory process. Calpain, a calcium-activated cysteine protease, has been shown to participate in the development of the inflammatory process. Therefore, for determination of the role of calpain in the pathophysiology of acute glomerulonephritis, transgenic mice that constitutively express high levels of calpastatin, a calpain-specific inhibitor protein, were generated. Wild-type mice that were subjected to anti-glomerular basement membrane nephritis exhibited elevated levels of calpain activity in kidney cortex at the heterologous phase of the disease. This was associated with the appearance in urine of calpain activity, which originated potentially from inflammatory cells, abnormal transglomerular passage of plasma proteins, and tubular secretion. In comparison with nephritic wild-type mice, nephritic calpastatin-transgenic mice exhibited limited activation of calpain in kidney cortex and limited secretion of calpain activity in urine. This was associated with less severe glomerular injury (including capillary thrombi and neutrophil activity) and proteinuria. There was a reduction in NF-kappaB activation, suggesting that calpain may participate in inflammatory lesions through NF-kappaB activation. There also was a reduction in nephrin disappearance from the surface of podocytes, indicating that calpain activity would enhance proteinuria by affecting nephrin expression. Exposure of cultured podocytes to calpain decreased nephrin expression, and, conversely, exposure of these cells to calpastatin prevented TNF-alpha from decreasing nephrin expression, demonstrating a role for the secreted form of calpain. Thus, both activation and secretion of calpains participate in the development of immune glomerular injury.

Extracellular calpains increase tubular epithelial cell mobility. Implications for kidney repair after ischemia.

Calpains are intracellular Ca2+-dependent cysteine proteases that are released in the extracellular milieu by tubular epithelial cells following renal ischemia. Here we show that externalized calpains increase epithelial cell mobility and thus are critical for tubule repair. In vitro, exposure of human tubular epithelial cells (HK-2 cells) to mu-calpain limited their adhesion to extracellular matrix and increased their mobility. Calpains acted primarily by promoting the cleavage of fibronectin, thus preventing fibronectin binding to the integrin alphavbeta3. Analyzing downstream integrin effects, we found that the cyclic AMP-dependent protein kinase A pathway was activated in response to alphavbeta3 disengagement and was essential for calpain-mediated increase in HK-2 cell mobility. In a murine model of ischemic acute renal failure, injection of a fragment of calpastatin, which specifically blocked calpain activity in extracellular milieu, markedly delayed tubule repair, increasing functional and histological lesions after 24 and 48 h of reperfusion. These findings suggest that externalized calpains are critical for tubule repair process in acute renal failure.

Development and potential of a biomimetic chitosan/type II collagen scaffold for cartilage tissue engineering / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Damaged articular cartilage has very limited capacity for spontaneous healing. Tissue engineering provides a new hope for functional cartilage repair. Creation of an appropriate cell carrier is one of the critical steps for successful tissue engineering. With the supposition that a biomimetic construct might promise to generate better effects, we developed a novel composite scaffold and investigated its potential for cartilage tissue engineering.</p><p><b>METHODS</b>Chitosan of 88% deacetylation was prepared via a modified base reaction procedure. A freeze-drying process was employed to fabricate a three-dimensional composite scaffold consisting of chitosan and type II collagen. The scaffold was treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. Ultrastructure and tensile strength of the matrix were carried out to assess its physico-chemical properties. After subcutaneous implantation in rabbits, its in vivo biocompatibility and degradability of the scaffold were determined. Its capacity to sustain chondrocyte growth and biosynthesis was evaluated through cell-scaffold co-culture in vitro.</p><p><b>RESULTS</b>The fabricated composite matrix was porous and sponge-like with interconnected pores measuring from 100-250 microm in diameter. After cross-linking, the scaffold displayed enhanced tensile strength. Subcutaneous implantation results indicated the composite matrix was biocompatible and biodegradable. In intro cell-scaffold culture showed the scaffold sustained chondrocyte proliferation and differentiation, and maintained the spheric chondrocytic phenotype. As indicated by immunohistochemical staining, the chondrocytes synthesized type II collagen.</p><p><b>CONCLUSIONS</b>Chitosan and type II collagen can be well blended and developed into a porous 3-D biomimetic matrix. Results of physico-chemical and biological tests suggest the composite matrix satisfies the constraints specified for a tissue-engineered construct and may be used as a chondrocyte carrier for cartilage tissue engineering.</p>

Comparative study of vertebral body stress distribution following insertion of artificial lumbar intervertebral disc / 中华外科杂志

<p><b>OBJECTIVE</b>To study vertebral body stress distribution of normal disc, post-Diskectomy and artificial disk respectively by 3-D finite element methods, and to explore artificial intervertebral disk insertion impact on stress distribution of vertebral body.</p><p><b>METHODS</b>Models of normal disk, post-Diskectomy, artificial disk and L(4 - 5) motion segment were established by using finite element software MSC. MARK, then vertebral body stress was analyzed through model of L(4 - 5) motion segment respectively.</p><p><b>RESULTS</b>The vertebral body's stress was the smallest after insertion of artificial intervertebral disk (AID), and its stress distributed equally. But the stress under post-discectomy was bigger than the normal disc's in all the motion state. On the other hand, the stress distribution state of the post-discectomy changed while the spine were in different motion state, during the spine flexion, the stress in the anterior of vertebral body was the biggest; While extension, in the posterior and in right flexion state, the biggest stress was in the right. While vertical compression and rotation, the stress distributed equally.</p><p><b>CONCLUSION</b>The results illustrate that the vertebral body's stress is the smallest after insertion of AID in 3 groups of all motion state, and its stress distributes equally. But the level of vertebral body stress increases after discectomy comparing with the normal group. In generally, it is much more reasonable that the disc is reconstructed with AID because of the biomechanical effect on vertebral body made by AID insertion.</p>