A comparative study on the clinical efficacy of percutaneous endoscopic lumbar discectomy and conventional open surgery in the treatment of lumbar disc herniation.

Objective: To analyze the efficacy of single-channel percutaneous endoscopic lumbar discectomy (PELD) and conventional open surgery in the treatment of lumbar disc herniation (LDH). Methods: This is a retrospective study. A total of 66 patients with LDH admitted to Tianjin Medical University from June 2017 to June 2018 were divided into two groups: the observation group (single-channel PELD) and the control group (posterior lumbar interbody fusion), with 33 cases in each group. The two groups were compared in terms of visual analogue scale(VAS), oswestry disability index (ODI), Japanese Orthopaedic Association Score(JOA), perioperative indicators, clinical efficacy, postoperative complications, changes in inflammatory factors and serum T lymphocyte subsets. Results: The operation time, incision length, intraoperative blood loss, time in bed, hospital stay in the observation group were all lower than those in the control group. At 7d after treatment, the improvement of ODI, VAS and JOA in the observation group were better than that in the control group. At the last follow-up, there was no significant difference in Cobb angle and lumbar lordosis angle between the two groups. The levels of serum IL-1, IL-6 and TNF-α in the observation group were lower than those in the control group. The degree of reduction of serum CD3+ and CD4+ in the observation group were higher than those in the control group. And the level of elevation of CD8+ in the observation group was lower than that in the control group. Moreover, there was no significant difference in CD4+/CD8+ level between the two groups. The excellent rate of surgical results in the observation group was higher than that in the control group. Complications occurred in both groups, with no significant difference between the two groups. Conclusions: Single-channel PELD can achieve superior clinical efficacy over conventional open surgery in the treatment of LDH.

Circular RNA hsa_circ_0001658 Inhibits Intervertebral Disc Degeneration Development by Regulating hsa-miR-181c-5p/FAS.

METHODS: We obtained microarray data (GSE116726, GSE67566) from Gene Expression Omnibus database, and differential expression level of ncRNA in nucleus pulposus (NP) tissues of IDD patients was analyzed. The potential circRNA-miRNA-mRNA regulatory network was analyzed by starBase. The effect of the interaction between hsa_circ_0001658, hsa-miR-181c-5p, and FAS on the proliferation and apoptosis of human neural progenitor cells (hNPCs) was studied. RESULTS: hsa_circ_0001658 was significantly upregulated (logFC > 2.0 and adj.P.Val < 0.01) in the NP tissues of IDD patients, and hsa-miR-181c-5p expression was downregulated (logFC < -2.0 and adj.P.Val < 0.01). Silencing of hsa-miR-181c-5p or overexpression of hsa_circ_0001658 inhibited the proliferation of hNPCs and promoted their apoptosis. hsa_circ_0001658 acted as a sponge of hsa-miR-181c-5p. hsa-miR-181c-5p downregulated the expression of Fas cell surface death receptor (FAS), promoted the proliferation, and inhibited the apoptosis of hNPCs. hsa_circ_0001658 functioned in hNPCs through targeting hsa-miR-181c-5p/FAS. CONCLUSION: Circular RNA hsa_circ_0001658 inhibits IDD development by regulating hsa-miR-181c-5p/FAS. It is expected to be a potential target for the therapy of IDD.

CT-based Morphometric Analysis of Approach of Percutaneous Transforaminal Endoscopic Lumbar Interbody Fusion.

OBJECTIVES: A radiographic study was designed to measure the relationship of the exiting nerve root and its surroundings to the corresponding intervertebral disc for percutaneous transforaminal endoscopic lumbar interbody fusion to better understand the regional anatomy and to improve clinical applications. METHODS: A retrospective study from January 2017 to October 2017 was conducted at Tianjin Hospital. CT images were obtained from patients presenting low back pain (110 patients), and analysis was performed bilaterally from L2-3 to L5 S1 . In the rotating coronal plane we analyzed: the nerve root-dural sac distance at the superior and inferior margins of the disc (Js, Ji); the nerve root-pedicle distance at the medial, middle, and lateral borders of the pedicle (Pa, Pb, Pc); the pedicle width (W); and the safe working zone, defined as a trapezoid bounded by the inferior pedicle and the exiting nerve root (S). In the transverse plane, the nerve root-articular process and the shortest distance for the nerve root-articular process joint surface were analyzed at the superior and inferior margins of the disc (Gs, Gi), respectively. The groups were analyzed using ANOVA, and paired t-tests were used to compare the left and right sides. RESULTS: From L2-3 to L5 S1 , the distance of the nerve root to the dural sac was larger at the inferior margin of the disc. From L2-3 to L5 S1 , each segment of the vertebral nerve root-pedicle distance gradually decreased from medial to lateral. From L2-3 to L5 S1 , the distance from the exiting nerve root to the middle and lateral margins of the pedicle gradually decreased, with L5 S1 being the minimum. Some significant differences were observed between the left and right sides for L4-5 and L5 S1 . The pedicle width of the vertebral body and the mean area for the safe working zone gradually increased from L2-3 to L5 S1 . In the axial plane, the shortest distance between the nerve root and articular process joint surface at the inferior margin of the disc was greater than the distance for the nerve root to the articular process at the superior margin of the disc from L2-3 to L5 S1 . There were no significant differences between the two sides. CONCLUSIONS: It is more difficult to implant a cage with a width of 10 mm above the L3-4 level. By removing part of the superior articular process, the safe working area can be expanded, and damage to the nerve or other structures can be avoided when implanting a cage.

Efficacy and safety of tranexamic acid in reducing blood loss in scoliosis surgery: a systematic review and meta-analysis.

OBJECTIVE: The purpose of this systematic review and meta-analysis of randomized controlled trials (RCTs) and non-RCTs was to gather data to evaluate the efficacy and safety of tranexamic acid (TXA) versus placebo after a scoliosis surgery. METHODS: The electronic databases including Embase, PubMed, CENTRAL (Cochrane Controlled Trials Register), Web of Science, and Google database were searched to identify relevant studies published from the time of the establishment of these databases up to May 2016. This systematic review and meta-analysis was performed according to the PRISMA statement criteria. The primary outcomes were total blood loss, intraoperative blood loss, and hemoglobin after surgery. The second outcome is need for transfusion. Stata 12.0 software was used for the meta-analysis. After testing for publication bias and heterogeneity across studies, data were aggregated for random-effects modeling when necessary. RESULTS: A total of 685 patients (347 patients in the TXA group and 338 in the control group) were finally included for this meta-analysis. The pooled results revealed that administration of TXA can decrease the total blood loss after scoliosis surgery [mean difference (MD) = 682.30, 95% confidence interval (CI) -930.60 to -434.00; P = 0.000] and intraoperative blood loss [(MD) = -535.28; 95% CI -683.74 to -368.82; P = 0.000]. For the hemoglobin (Hb) value after scoliosis surgery, TXA can decrease the Hb value for 0.51 dL [(MD) = 0.51; 95% CI 0.25-0.78; P = 0.000]. There is no statistically significant difference between the TXA versus placebo in terms of the need for transfusion (relative risk = 0.55, 95% CI 0.25-1.20, P = 0.132). CONCLUSION: Based on the current meta-analysis, TXA can decrease the total blood loss and intraoperative blood loss during scoliosis surgery. It is recommended that it be routinely used in scoliosis surgery. High-dose TXA (>20 mg/kg) is more effective than low-dose TXA (<20 mg/kg) in controlling blood loss. However, for the need for transfusion, more high-quality RCTs need to be identified.

Thoracic Endoscopic-Assisted Mini-Open Surgery for Thoracic and Thoracolumbar Spinal Cord Compression.

Intervertebral disc herniation is a common cause of spinal cord compression, especially for the thoracic and thoracolumbar spinal cord, which has limited buffer space in the spinal canal. Spinal cord compression usually causes decreased sensation and paralysis of limbs below the level of compression, urinary and fecal incontinence, and/or urinary retention, which brings great suffering to the patients and usually requires surgical intervention. Thoracotomy or abdominothoracic surgery is usually performed for the thoracolumbar cord compression caused by hard intervertebral disc herniation. However, there is high risk of trauma and complications with this surgery. To reduce the surgical trauma and obtain good visibility, we designed athoracic endoscopic-assisted mini-open surgery for thoracic and thoracolumbar disc herniation, and performed this procedure on 10 patients who suffered from hard thoracic or thoracolumbar spinal cord compression. During the procedure, the thoracic endoscopy provided clear vision of the surgical field with a good light source. The compression could be fully exposed and completely removed, and no nerve root injury or spinal cord damage occurred. All patients achieved obvious recovery of neurological function after this procedure. This technique possesses the merits of minimal trauma, increased safety, and good clinical results. The aim of this study is to introduce this thoracic endoscopic-assisted mini-open surgery technique, and we believe that this technique will be a good choice for the thoracic and thoracolumbar cord compression caused by hard intervertebral disc herniation.

Intervertebral Fusion with Mobile Microendoscopic Discectomy for Lumbar Degenerative Disc Disease.

The aim of this article is to introduce a technique for lumbar intervertebral fusion that incorporates mobile microendoscopic discectomy (MMED) for lumbar degenerative disc disease. Minimally invasive transforaminal lumbar interbody fusion is frequently performed to treat degenerative diseases of the lumbar spine; however, the scope of such surgery and vision is limited by what the naked eye can see through the expanding channel system. To expand the visual scope and reduce trauma, we perform lumbar intervertebral fusion with the aid of a MMED system that provides a wide field through freely tilting the surgical instrument and canals. We believe that this technique is a good option for treating lumbar degenerative disc disease that requires lumbar intervertebral fusion.

Construction Strategy and Progress of Whole Intervertebral Disc Tissue Engineering.

Degenerative disc disease (DDD) is the major cause of low back pain, which usually leads to work absenteeism, medical visits and hospitalization. Because the current conservative procedures and surgical approaches to treatment of DDD only aim to relieve the symptoms of disease but not to regenerate the diseased disc, their long-term efficiency is limited. With the rapid developments in medical science, tissue engineering techniques have progressed markedly in recent years, providing a novel regenerative strategy for managing intervertebral disc disease. However, there are as yet no ideal methods for constructing tissue-engineered intervertebral discs. This paper reviews published reports pertaining to intervertebral disc tissue engineering and summarizes data concerning the seed cells and scaffold materials for tissue-engineered intervertebral discs, construction of tissue-engineered whole intervertebral discs, relevant animal experiments and effects of mechanics on the construction of tissue-engineered intervertebral disc and outlines the existing problems and future directions. Although the perfect regenerative strategy for treating DDD has not yet been developed, great progress has been achieved in the construction of tissue-engineered intervertebral discs. It is believed that ongoing research on intervertebral disc tissue engineering will result in revolutionary progress in the treatment of DDD.

In vitro cartilage production using an extracellular matrix-derived scaffold and bone marrow-derived mesenchymal stem cells.

BACKGROUND: Cartilage repair is a challenging research area because of the limited healing capacity of adult articular cartilage. We had previously developed a natural, human cartilage extracellular matrix (ECM)-derived scaffold for in vivo cartilage tissue engineering in nude mice. However, before these scaffolds can be used in clinical applications in vivo, the in vitro effects should be further explored. METHODS: We produced cartilage in vitro using a natural cartilage ECM-derived scaffold. The scaffolds were fabricated by combining a decellularization procedure with a freeze-drying technique and were characterized by scanning electron microscopy (SEM), micro-computed tomography (micro-CT), histological staining, cytotoxicity assay, biochemical and biomechanical analysis. After being chondrogenically induced, the induction results of BMSCs were analyzed by histology and Immunohisto-chemistry. The attachment and viability assessment of the cells on scaffolds were analyzed using SEM and LIVE/DEAD staining. Cell-scaffold constructs cultured in vitro for 1 week and 3 weeks were analyzed using histological and immunohistochemical methods. RESULTS: SEM and micro-CT revealed a 3-D interconnected porous structure. The majority of the cartilage ECM was found in the scaffold following the removal of cellular debris, and stained positive for safranin O and collagen II. Viability staining indicated no cytotoxic effects of the scaffold. Biochemical analysis showed that collagen content was (708.2-44.7) µg/mg, with GAG (254.7 ± 25.9) µg/mg. Mechanical testing showed the compression moduli (E) were (1.226 ± 0.288) and (0.052 ± 0.007) MPa in dry and wet conditions, respectively. Isolated canine bone marrow-derived stem cells (BMSCs) were induced down a chondrogenic pathway, labeled with PKH26, and seeded onto the scaffold. Immunofluorescent staining of the cell-scaffold constructs indicated that chondrocyte-like cells were derived from seeded BMSCs and excreted ECM. The cell-scaffold constructs contained pink, smooth and translucent cartilage-like tissue after 3 weeks of culture. We observed evenly distributed cartilage ECM proteoglycans and collagen type II around seeded BMSCs on the surface and inside the pores throughout the scaffold. CONCLUSION: This study suggests that a cartilage ECM scaffold holds much promise for in vitro cartilage tissue engineering.

Novel cartilage-derived biomimetic scaffold for human nucleus pulposus regeneration: a promising therapeutic strategy for symptomatic degenerative disc diseases.

Because current therapies have not always been successful and effective, the possibility of regenerating the nucleus pulposus (NP) through a tissue-engineered construct offers a novel therapeutic possibility for symptomatic degenerative disc diseases (DDDs). However, more research is necessary to identify the optimal scaffold, cell type and mixture of signal factors needed for NP regeneration. Numerous possible scaffolds for NP regeneration have been investigated; they have many shortcomings in common. Various biological scaffolds derived from decellularized tissue and organs have been successfully used in tissue engineering and received approval for use in humans. Regretfully, harvesting of human NP is difficult and only small amounts can be obtained. The macromolecules of cartilage, which include collagen and proteoglycan aggrecan, are similar to those of the extracellular matrix of immature NP. Recent studies have shown that adipose-derived stem cells (ADSC) can be induced to develop NP-like phenotypes when stimulated by appropriate signals. We thus reasonably postulated that an ideal NP scaffold for tissue engineering could be fabricated from decellularized cartilage matrix (DCM). Furthermore, a combination of ADSCs and DCM-derived biomimetic scaffolds would be advantageous in NP tissue engineering and, in the long run, could become an effective treatment option for symptomatic DDD.

Gap junction -mediated cAMP movement between oocytes and somatic cells.

Cyclic AMP (cAMP) plays a critical role in oocyte meiotic maturation. However, the source of cAMP surge prior to maturation and the direction of gap junction-dependent cAMP movement are unclear. In this study, inhibition of gap junctional communication (GJC) using carbenoxolone (3.5 h) induced meiotic resumption in ~90% of follicle-enclosed oocytes (FEOs). The concentration of cAMP in a single oocyte was higher than that in a single cumulus cell, suggesting that the movement of cAMP proceeds from the oocyte to cumulus cells under passive diffusion. The mRNAs of adenylyl cyclases and the corresponding proteins were mainly detected in oocytes. Persistent or transient incubation with forskolin induced meiotic resumption in FEOs. The maturation induced by persistent forskolin treatment was inhibited by carbenoxolone. However, carbenoxolone had no effect on the maturation of FEOs transiently treated with forskolin or persistently treated with follicle-stimulating hormone. Oocyte maturation was inhibited by sequential treatment with carbenoxolone followed by forskolin. The carbenoxolone-induced maturation was accompanied by a cAMP surge, increased PDE3A and MAPK activation, and decreased levels of cGMP and cAMP-dependent PKA I activation.

The usefulness of magnetic resonance imaging for sequestered lumbar disc herniation treated with endoscopic surgery.

Forty two patients with sequestered lumbar intervertebral disc herniation were treated by endoscopic surgery with the mobile Endospine system. The herniations and migration were confirmed on magnetic resonance imaging (MRI). The interlamina fenestration and pars interarticularis fenestration approaches were used for intracanal herniations and far lateral lumbar disc herniations (FLLDH) according to the degree of migration as observed on MRI. Sequestered herniations were exposed and removed completely with the mobile endoscopic system for all patients without neurologic complications or dural tears. Intraoperative findings were compared with preoperative MRI results. Of 24 caudal intracanal herniations, 15 had sequestered nuclei located ventrally beneath the dural theca and the transverse nerve root; 5 were between the transverse nerve root and dural theca (axillary); 4 were dorsally located on the nerve root and dural theca. However, preoperative MRI did not clearly display the sequestered nuclei between the transverse nerve root and dural theca (axillary), or the dorsally migrated disc on the nerve root and dural theca. Of 6 cranial intracanal herniations, 5 had free fragments located beneath the dural theca, and 1 dorsal to the dural sac. Of the 2 dorsal herniations, the migrated nucleus adhered to the dural sac was not found on preoperative MRI; in the other case, dorsal migration of nucleus, annulus and endplate around the dural sac was also not observed on preoperative MRI. Among the 10 FLLDH, preoperative MRI showed cranial migration and foraminal obstruction in all patients, with sequestered disc material at the ventral and medial sides of the exiting nerve root, displacing the exiting nerve root and ganglion cranially and dorsally. During the 12 to 48 month postoperative follow-up period, 26 patients had excellent clinical results and 15 patients had good results (Macnab scale). In conclusion, MRI is important for evaluating sequestered lumbar disc herniation, although it has its limitations. Sequestered herniations can be exposed and removed completely with the mobile endoscopic system.

Long-term results and radiographic findings of percutanous vertebroplasties with polymethylmethacrylate for vertebral osteoporotic fractures.

BACKGROUND: Percutaneous vertebroplasty (PVP) has become a popular procedure for painful vertebral osteoporotic fracture (VOF), with immediate pain relief and improved mobility; however, polymethylmethacrylate (PMMA) injected into the vertebral body is not absorbable and little information is available concerning the long-term results. In this retrospective study, we evaluated the long-term clinical results and radiological changes after PVPs for VOFs. METHODS: Fifty-one patients with VOFs were treated by PVPs with PMMA between 2000 and 2004. After > 7 years of follow-up, eight patients had died from causes unrelated to the intervention and 12 patients were lost to follow-up, thus leaving 31 patients available for evaluation with an average length of follow-up of 9.2 years (follow-up rate, 72.1%). Among these 31 patients, the PMMA was injected at 43 levels with a mean volume of 4.3 ml per level (range, 2 - 6 ml). The pain was assessed with a visual analog scale (VAS), and the mobility was graded as walking without difficulty (grade 1), walking with assistance (grade 2), and bedridden (grade 3). Plain radiographs and computed tomography (CT) were obtained and assessed pre-operatively, immediately post-operatively, and after 7 years of follow-up. The PMMA, vertebral height, and Cobb angle were assessed and compared. RESULTS: All of the patients experienced pain relief and improved mobility after intervention and during the follow-up period. Cement leakage was detected in post-operative CT scans in 9 of 51 patients, but without neurological compromise. For the 31 patients followed up over 7 years, the VAS decreased from 8.3 ± 2.6 pre-operatively, to 2.1 ± 1.6 immediately post-operatively, and 1.0 ± 0.9 at the final follow-up evaluation, with significantly improved mobility. Additional compression fractures occurred at adjacent levels in three patients, and there were no new fractures at the augmented vertebrae. Based on a review of the radiographs, neither loose nor displaced cement was detected. The changes in vertebral height and Cobb angle were not significant. On CT scans, the cement closely contacted or infiltrated the trabecular bone. The boundary between the cement and trabecular bone was indistinct and there was no evident radiolucent gap between the cement and trabecular bone. CONCLUSIONS: At an average follow-up of 9.2 years, PVPs provided sustained pain relief and improved mobility in patients with VOFs. The PMMA injected into the vertebral body combined closely with the host trabecular bone without adverse reactions.

[Insertion technique and clinical application of regional method axis pedicle screw].

OBJECTIVE: To explore the clinical efficacies and outcomes of regional method axis pedicle screw insertion technique. METHODS: During the period of April 2004 to June 2010, a total of 23 cases with traumatic instability of upper cervical vertebrae were recruited. There were 19 males and 4 females with a mean age of 45.8 years. They underwent surgical operations after an excellent traction reduction of cervical vertebrae. The entry points were drawn on axial facet joint and all of them distributed in the region of upper inner 1/4 of lower articular process. So the regional method was employed to determine the entry point. All subjects underwent the reconstruction of posterior stability. Axial pedicle screws were inserted by the insertion technique of axial pedicle screw via the "regional method". The entry region was in the upper inner 1/4 area of lower articular process. The entry angle, medial inclination and superior inclination were determined by the direction of inner wall and upper wall of isthmus. Postoperative cervical radiography and CT examination were performed to confirm the screw position. RESULTS: Forty-six axial pedicle screws were implanted. No significant complications occurred. All screws stayed in excellent positions without the invasion of vertebral artery and spinal canal. CONCLUSIONS: The "regional method" insertion technique of axial pedicle screw require no memory of complex entry points and entry angle parameters. And there is no need of identifying the anatomical landmarks. Thus this approach is accurate, safe and suitable for most patients.

[Lateral position one-stage combined posteroanterior approaches for the treatment of lumbosacral tuberculous spondylitis].

OBJECTIVE: To investigate the feasibility of a one-stage combined posteroanterior approaches for the treatment of lumbosacral tuberculous spondylitis with the patients lying in a lateral position. METHODS: A retrospective review was conducted for 15 patients with lumbosacral tuberculosis undergoing one-stage combined posteroanterior approaches for radical lesion resection and reconstruction. All patients were observed and evaluated by clinical and imaging studies. RESULTS: Operative posture:11 cases for right side and 4 cases for left side. The mean operative duration was 280 min (range: 230 - 380 min) and the mean estimated volume of blood loss 1720 ml (range: 1100 - 3000 ml). Imaging results: No recurrence of tuberculose focus was found until the last follow-up. Upon image reviewing, it showed no loosening or displacement except for two cases of slightly collapsed titanium mesh. Preoperative and postoperative changes in the degree of lumbar lordosis were statistically significant [(20 ± 5)° vs (31 ± 5)°, P < 0.05]. The Kirkaldy-Willis classification rating yielded satisfactory results for 13 cases. CONCLUSION: The patients with lumbosacral tuberculosis undergoing one-stage combined posteroanterior approaches may achieve radical lesion resection, posteroanterior collaboration and reconstruction. It avoids a 2-stage operation, eliminates the need of changing a patient's body position with secondary sterilization and shortens the operative duration. Lumbosacral surgery for tuberculosis combines the respective advantages of anterior, posterior and combined posteroanterior approaches and yet makes up for their deficiencies.

[In vitro cartilage tissue engineering with cartilage extracellular matrix-derived porous scaffolds and bone marrow mesenchymal stem cells].

OBJECTIVE: To develop a novel cartilage ECM-derived porous scaffold (CEDPS) and investigate the attachment, proliferation and distribution of bone marrow mesenchymal stem cells (BMSCs) cultured in vitro within the scaffolds. METHODS: Cartilage microfilaments were prepared after pulverization and gradient centrifugation and prepared into suspension after acellularization treatment. The scaffolds were examined by histological staining, scanning electron microscope (SEM), biochemical and biomechanical analysis. After labeling with PKH26, the canine BMSCs were seeded onto the scaffolds. The attachment, proliferation and differentiation of cells were observed by inverted fluorescent microscope and SEM. RESULTS: On histology, most extracellular matrices were retained in the scaffold after the removal of cell fragments. Safranin O staining and immunofluorescence examination with collagen II antibodies provided positive results. Biochemical analysis showed that the collagen content was (708.2 ± 44.7) µg/mg, glycosaminoglycan (254.7 ± 25.9) µg/mg and DNA (0.021 ± 0.007) µg/mg. Mechanical testing showed the compression moduli (E) were (1.226 ± 0.288) and (0.052 ± 0.007) MPa under dry and wet conditions respectively. Inverted fluorescent microscope and SEM showed moderate cell adhesion, chondrocyte-like morphology and matrix synthesis around cells. CONCLUSION: The CEDPS retains most extracellular matrices after a thorough decellularization so as to possess an excellent microstructure with ideal biomechanical characteristics and a good biocompatibility. Thus it is a suitable candidate as an alternative cell-carrier for cartilage tissue engineering. Chondrogenic BMSCs and CEDPS may be used to construct cartilage-like tissue in vitro.

Evaluation of an extracellular matrix-derived acellular biphasic scaffold/cell construct in the repair of a large articular high-load-bearing osteochondral defect in a canine model.

BACKGROUND: Osteochondral lesion repair is a challenging area of orthopedic surgery. Here we aimed to develop an extracellular matrix-derived, integrated, biphasic scaffold and to investigate the regeneration potential of the scaffold loaded with chondrogenically-induced bone marrow-derived mesenchymal stem cells (BMSCs) in the repair of a large, high-load-bearing, osteochondral defect in a canine model. METHODS: The biphasic scaffolds were fabricated by combining a decellularization procedure with a freeze-drying technique and characterized by scanning electron microscopy (SEM) and micro-computed tomography (micro-CT). Osteochondral constructs were fabricated in vitro using chondrogenically-induced BMSCs and a biphasic scaffold, then assessed by SEM for cell attachment. Osteochondral defects (4.2 mm (diameter) × 6 mm (depth)) were created in canine femoral condyles and treated with a construct of the biphasic scaffold/chondrogenically-induced BMSCs or with a cell-free scaffold (control group). The repaired defects were evaluated for gross morphology and by histological, biochemical, biomechanical and micro-CT analyses at 3 and 6 months post-implantation. RESULTS: The osteochondral defects of the experimental group showed better repair than those of the control group. Statistical analysis demonstrated that the macroscopic and histologic grading scores of the experimental group were always higher than those of the control group, and that the scores for the experimental group at 6 months were significantly higher than those at 3 months. The cartilage stiffness in the experimental group (6 months) was (6.95 ± 0.79) N/mm, 70.77% of normal cartilage; osteochondral bone stiffness in the experimental group was (158.16± 24.30) N/mm, 74.95% of normal tissue; glycosaminoglycan content of tissue-engineered neocartilage was (218 ± 21.6) µg/mg (dry weight), 84.82% of native cartilage. Micro-CT analysis of the subchondral bone showed mature trabecular bone regularly formed at 3 and 6 months, with no significant difference between the experimental and control groups. CONCLUSION: The extracellular matrix-derived, integrated, biphasic scaffold shows potential for the repair of large, high-load-bearing osteochondral defects.

[Effect of intervertebral position on range of motion after artificial lumbar total disc replacement and clinical management].

OBJECTIVE: To discuss the effect of SB Charité lumbar artificial disc position on intervertebral range of motion (ROM) and clinical management. METHODS: Between 2004 and 2007, 30 discogenic low back pain patients confirmed by discography underwent 1/2-level total disc replacement (TDR) implantation with 32 prostheses. There were 12 males and 18 females with a mean age of 44 years old (range: 28-55). All indexed levels were inserted between L4-S1 involving L4-5 (n = 9), L5S1 (n = 19) and L4-S1 (n = 2). The clinical outcome was measured by Oswestry disability index (ODI) and visual analogue scale (VAS). Radiographic outcome measures included flexion/extension ROM, restoration of operative level intervertebral disc height, maintenance of disc height at the final follow-up. A technique previously described by McAfee was used to evaluate TDR position in three groups. Paired t test was used to compare the preoperative and postoperative ROM and clinical ODI, VAS scores. RESULTS: Twenty-eight patients were followed-up for 24-60 months with an average of 38 months. All the prostheses were solidly immobilized with the vertebral endplate. No disc prosthesis rupture, dislocation, subsidence or heterotopic ossification was observed. Preoperative ODI, VAS back pain and VAS leg pain scores were 70.34 ± 9.21, 7.46 ± 2.65, 4.81 ± 2.75;and postoperative corresponding scores 7.65 ± 8.61, 0.68 ± 0.69, 0.35 ± 0.32 respectively. The positions of disc prostheses were graded as Group I, excellent, n = 17; Group II, suboptimal, n = 6; Group III, poor, n = 5. Preoperative mean intervertebral flexion/extension ROM (degree) of Group I to Group III were 9.75 ± 2.80, 10.30 ± 1.20 and 10.08 ± 2.43 respectively. The postoperative mean intervertebral flexion/extension ROM (degree): 6.68 ± 3.83, 4.22 ± 3.51 and 3.48 ± 3.56 respectively. Postoperatively all clinical outcome scores were lower than preoperative ones. Disc height was significantly restored. Mean intervertebral ROM decreased versus preoperative. Although there was a tendency of mean intervertebral ROM increasing with a better disc position, no statistical difference was observed. CONCLUSION: The mid-term clinical outcome of TDR is generally satisfactory. The TDR position influences intervertebral ROM to some extent. Efficient clinical management can reduce prosthetic malposition.

Bilateral decompression via unilateral fenestration using mobile microendoscopic discectomy technique for lumbar spinal stenosis.

OBJECTIVE: To evaluate the feasibility and clinical efficacy of bilateral decompression via unilateral fenestration (BDUF) with mobile microendoscopic discectomy (MMED) for lumbar spinal stenosis. METHODS: From June 2007 to June 2009, 32 patients were treated by the technique of BDUF with MMED for lumbar spinal stenosis in our hospital. All patients complained of bilateral sciatic neuralgia and intermittent claudication that was dominant in one limb. CT scan and MRI revealed disc herniation and bilateral stenosis of the spinal canal. Patients with bilateral severe osseous stenosis and multilevel stenosis were excluded. RESULTS: The procedure was technically successful in all patients, bilateral decompression and spinal canal enlargement being achieved by unilateral fenestration. The mean operative time was 70 min (range, 50-100 min), with a mean blood loss of 150 ml (range, 50-350 ml). No significant complication was noted; dural tears were encountered in only two patients without obvious side effects. The patients were followed up for 3 to 24 months (mean, 12 months) and the clinical results were excellent in 21 cases and good in 11 cases according to the MacNab scale. CONCLUSION: The procedure of BDUF can be performed in conjunction with the MMED technique for lumbar spinal stenosis with good clinical results; however, severe bilateral osseous stenosis may be not suitable for this technique.

[Mini-invasive extraperitoneal approach for anterior lumbar surgery].

OBJECTIVE: To study a mini-invasive extraperitoneal approach to lumbar spine and discuss its exposure technique, complications and management. METHOD: Anterior lumbar surgery was performed in 52 patients via the mini-invasive anterior extraperitoneal approach. Diagnoses included lumbar degenerative instability (n=23), discogenic lumbar pain (n=25), lumbosacral congenital deformity (n=2) and revision after posterior laminectomy & discectomy (n=2). The patients underwent anterior lumbar interbody fusion (n=32) and total disk replacement (n=20). The operated disks included L(4-5) and L5-S1. There were single level (n=47) and double level (n=5). Operation time, blood loss, perioperative complications, postoperative bed-leaving time, incision length, pain of abdomen incision and postoperative hospitalization duration were recorded in details. RESULTS: All cases were exposed clearly and no one needed to prolong incision or change operation for an insufficient exposure. Average operation time was 85 min, average blood loss 155 ml, average postoperative bed-leaving time 3 days and average incision length 6.5 cm. All cases felt very little pain of abdominal incision and postoperative hospitalization duration was 7-10 days. Perioperative complications included vena cava tear (n=1), peritoneum tear (n=2), postoperative abdominal distention (n=3) and postoperative fever (n=5). No retrograde ejaculation was found in all male cases. CONCLUSION: The technique of mini-invasive extraperitoneal approach to anterior lumbar has such multiple advantages as fewer complications, less trauma, excellent exposure to anterior vertebrae and disk and without destruction of posterior spinal component