Search

Objective: To review the research progress in the treatment of high-grade spondylolisthesis (HS), in order to provide a reference for clinical treatment decision-making., Methods: The literature related to the treatment of HS at home and abroad in recent years was widely reviewed. The methods of conservative treatment, in situ fusion, and spondylolisthesis reduction were analyzed and summarized., Results: Surgical treatment is the main treatment of HS, but which method is the best is still controversial. The advantages, disadvantages, and applicability of various operations are also different, so individualized analysis is needed in clinic., Conclusion: The treatment plan of HS needs to be considered comprehensively according to the individual condition of the patient. It will be an important research direction to further compare the existing treatment methods and develop more safe and effective new technology.

Objective: To review and evaluate the technical advantages and disadvantages and research progress of percutaneous endoscopic lumbar interbody fusion., Methods: The domestic and foreign related research literature on percutaneous endoscopic lumbar interbody fusion was extensively consulted. The advantages, disadvantages, and effectiveness were summarized. And the development trend of this technology was prospected., Results: Compared with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), percutaneous endoscopic lumbar interbody fusion has less intraoperative and postoperative bleeding, better improvement of low back pain in the early stage after operation, and similar long-term effectiveness, fusion rate, and incidence of complication, but a longer learning curve. The operation time of biportal and large-channel uniportal endoscopic lumbar fusion is close to that of MIS-TLIF, but the operation time of small-channel uniportal endoscopic fusion is longer than that of MIS-TLIF., Conclusion: Percutaneous endoscopic lumbar interbody fusion has the advantages of less trauma and good effectiveness, but its learning curve is long, and indications should be strictly selected for this operation. In the future, with the continuous development and complementation of various endoscopic fusion technologies, this technology will gain better application prospects.

Objective: To compare the effectiveness of percutaneous coaxial large-channel endoscopic lumbar interbody fusion (PE-LIF) and minimal invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of degenerative lumbar spinal stenosis., Methods: The clinical data of 134 patients with single-segment degenerative lumbar spinal stenosis who met the selection criteria between January 2019 and January 2021 were retrospectively analyzed, including 52 cases in PE-LIF group and 82 cases in MIS-TLIF group. There was no significant difference in general data such as gender, age, disease duration, surgical segment, and preoperative visual analogue scale (VAS) scores of low back pain and lower extremity pain, and Oswestry disability index (ODI) between the two groups ( P >0.05). The operation time, intraoperative blood loss, postoperative drainage, hospitalization stay, and complications were recorded and compared between the two groups. The level of serum creatine kinase (CK) was recorded at 1 day before operation and at 1 and 3 days after operation to evaluate intraoperative muscle damage. The Brantigan criteria was used to evaluate the interbody fusion in the two groups. The VAS scores of low back pain and lower extremity pain at 1 day before operation and at 3 days, 3 months, and 1 year after operation, and the ODI scores at 1 day before operation and at 3 months and 1 year after operation were recorded and compared between the two groups., Results: There was no significant difference in operation time and hospitalization stay between the two groups ( P >0.05). The intraoperative blood loss and postoperative drainage in the PE-LIF group were significantly lower than those in the MIS-TLIF group ( P <0.05). There was no significant difference in serum CK between the two groups before operation ( P >0.05), and the serum CK in the PE-LIF group at 1 and 3 days after operation were significantly lower than those in the MIS-TLIF group ( P <0.05). All patients were followed up regularly for 1 year. The postoperative VAS scores of low back pain and lower extremity pain and ODI score in both groups were significantly lower than those before operation ( P <0.05); there was no significant difference between the two groups ( P >0.05). At 1 year after operation, 48 patients in PE-LIF group had successful interbody fusion, and 77 patients in MIS-TLIF group had successful interbody fusion. There was no significant difference in the interbody fusion distribution between the two groups at 3 months and 1 year after operation ( P >0.05). There were 2 and 3 cases of lower limb numbness, 1 and 3 cases of neuroedema pain, 1 and 1 case of Cage displacement, 1 and 1 case of pedicle screw loosening in the PE-LIF group and MIS-TLIF group, respectively. No infection or dural sac tearing occurred in the two groups. There was no significant difference in the incidence of complications between the two groups (9.6% vs. 9.8%) ( χ 2 =0.001, P =0.979)., Conclusion: In the treatment of single-segment degenerative lumbar spinal stenosis, PE-LIF can achieve similar effectiveness as MIS-TLIF, and PE-LIF has less intraoperative blood loss and less muscle damage.

Objective: A prospective randomized controlled trial was conducted to study the effectiveness and safety of intravenous different doses tranexamic acid (TXA) in single-level unilateral minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF)., Methods: The patients treated with single-level unilateral MIS-TLIF between September 2019 and October 2020 were enrolled and randomly classified into low-dose TXA (LD) group ( n =39), high-dose TXA (HD) group ( n =39), and placebo-controlled (PC) group ( n =38). The LD, HD, and PC groups received intravenous TXA 20 mg/kg, TXA 50 mg/kg, the same volume of normal saline at 30 minute before skin incision after general anesthesia, respectively. There was no significant difference on baseline characteristics and preoperative laboratory results among 3 groups ( P >0.05), including age, gender, body mass index, surgical segments, hematocrit (HCT), hemoglobin (HGB), prothrombin time (PT), international normalized ratio (INR), D-dimer, fibrin degradation products (FDP), activated partial prothromboplastin time (APTT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (Cr), urea. The intraoperative blood loss (IBL), postoperative drainage volume, operation time, total blood loss (TBL), hidden blood loss (HBL), blood transfusion, hematological examination indexes on the first day after operation, and the incidence of complications within 1 month were compared among the 3 groups., Results: There were 3, 2, and 4 patients in the LD, HD, and PC groups who underwent autologous blood transfusion, respectively, and there was no allogeneic blood transfusion patients in the 3 groups. There was no significant difference in IBL, postoperative drainage volume, and operation time between groups ( P >0.05). The TBL, HBL, and the decreased value of HGB in LD and HD groups were significantly lower than those in PC group ( P <0.05), and TBL and HBL in HD group were significantly lower than those in LD group ( P <0.05); the decreased value of HGB between LD group and HD group showed no significant difference ( P >0.05). On the first day after operation, D-dimer in LD and HD groups were significantly lower than that in PC group ( P <0.05); there was no significant difference between LD and HD groups ( P >0.05). There was no significant difference in other hematological indexes between groups ( P >0.05). All patients were followed up 1 month, and there was no TXA-related complication such as deep venous thrombosis of lower extremity, pulmonary embolism, and epilepsy in the 3 groups., Conclusion: Intravenous administration of TXA in single-level unilateral MIS-TLIF is effective and safe in reducing postoperative TBL and HBL within 1 day in a dose-dependent manner. Also, TXA can reduce postoperative fibrinolysis markers and do not increase the risk of thrombotic events, including deep venous thrombosis and pulmonary embolism.

Objective: To review the definition and possible etiologies for C 5 palsy., Methods: The literature on C 5 palsy at home and abroad in recent years was extensively reviewed, and the possible etiologies were analyzed based on clinical practice experience., Results: There are two main theories (nerve root tether and spinal cord injury) accounting for the occurrence of C 5 palsy, but both have certain limitations. The former can not explain the occurrence of C 5 palsy after anterior cervical spine surgery, and the latter can not explain that the clinical symptoms of C 5 palsy is often the motor dysfunction of the upper limb muscles. Based on the previous reports, combining our clinical experience and research, we propose that the occurrence of C 5 palsy is mainly due to the instrumental injury of anterior horn of cervical spinal cord during anterior cervical decompression. In addition, the C 5 palsy following surgery via posterior approach may be related to the nerve root tether caused by the spinal cord drift after decompression., Conclusion: In view of the main cause of C 5 palsy after cervical decompression, it is recommended to reduce the compression of the spinal cord by surgical instruments to reduce the risk of this complication.

Objective: To summarize the research progress of the regulatory role of microRNA (miRNA) in osteogenic differentiation of mesenchymal stem cells (MSCs) and its application as a therapeutic target and diagnostic tool in orthopedic diseases., Methods: The recent literature on the regulation of MSCs osteogenic differentiation by miRNAs was extensively reviewed, and its regulatory mechanism and its application as a therapeutic target and diagnostic tool in orthopedic diseases were reviewed., Results: miRNAs are small endogenous non-coding RNAs with a length of 20-22 nucleotides, which play an important role in the osteogenic differentiation of MSCs. Osteogenesis begins with the differentiation of MSCs into mature osteoblasts, and each stage of dynamic homeostasis of bone metabolism is associated with the regulation of different miRNAs. miRNAs are regulated from the post-transcriptional level by mRNAs cleavage, degradation, translational repression, or methylation. In addition, current studies suggest that miRNAs can be used as a new diagnostic tool and therapeutic target for orthopedic diseases., Conclusion: Further study on the regulation mechanism of miRNAs will provide more ideas for finding new therapeutic targets and diagnostic tools for orthopedic disease.

Objective: To assess the reliability, effectiveness, and the safety of full endoscopic transforaminal decompression (FETD) under local anesthesia guided by the classification of lateral region of the lumbar spinal canal (CLLSC) in treating lumbar spinal stenosis (LSS) in geriatric patients., Methods: The clinical data of 63 geriatric patients with LSS met the inclusion criteria underwent FETD surgery between June 2015 and July 2017 were retrospectively analyzed. There were 37 males and 26 females, with a median age of 76 years [interquartile range (IQR), 73-80 years], and a median symptomatic duration of 55 months (IQR, 16-120 months). There were 17 cases of grade B and 46 cases of grade C based on the Schizas morphological grading system. CLLSC was used for imaging evaluation for the stenotic condition, and intra-class correlation coefficients (ICC) were used to test intra-observer and inter-observer reliability of CLLSC. The stenotic condition of patients was re-evaluated by the surgeon after operation, and the results were compared with the findings of preoperative CLLSC. The visual analogue scale (VAS) score for low back pain and leg pain recorded before operation, and at 1 day, 3 months, and 6 months after operation, and last follow-up were used to assess the pain relieving; the functional improvement was evaluate by Oswestry disability index (ODI); the modified Macnab criteria were used to self-evaluate the surgical satisfaction., Results: The operation were successfully performed for all patients, with a median operation time of 75 minutes (IQR, 65-85 minutes), postoperative hospitalization stay of 48 hours (IQR, 48-72 hours), and the time to ambulation after operation of 24 hours (IQR, 24-24 hours). Sixty-three patients were followed-up and with a median follow-up time of 18 months (IQR, 13-20 months). Based on preoperative CLLSC classification, there were 72 stenotic zones, distributed 16 in zone 1, 6 in zone 2, 3 in zone 3, 2 in zone 4, 7 in zone 5, 34 in zones 1+2, 2 in zones 3+4, and 2 in zones 4+5. Perioperative complications occurred in 4 cases (6.3%), including 2 cases of intraoperative dural sac tear, 1 of preoperative numbness symptom aggravation, and 1 of postoperative urinary retention. VAS score of leg pain and ODI score at each time point after operation were significantly improved compared with those before operation ( P <0.05). VAS scores of low back pain showed no significant difference between pre- and post-operation ( P >0.05). At last follow-up, based on the modified Macnab criteria, 19 cases were excellent, 37 were good, 6 were fair, and 1 was poor, and the excellent and good rate was 88.9%. The reliability analysis showed that CLLSC had substantial intra-observer reliability in the geriatric population, with an average ICC of 0.78. There was also a substantial inter-observer reliability, with an average ICC of 0.73. While comparing the preoperative CLLSC results with the postoperative CLLSC results, 53 patients (73.6%) were in full agreement, 15 patients (20.8%) were in partial agreement, and 4 patients (5.6%) were not., Conclusion: CLLSC has high reliability in the diagnosis of LSS in the geriatric patients. Combined FETD with CLLSC, accurate diagnosis, and minimal invasion can be performed to achieve safe and effective result.

Objective: To observe the effectiveness and safety of percutaneous endoscopic transforaminal bilateral decompression for severe central lumbar spinal stenosis., Methods: A retrospective analysis of 44 patients with single-segment severe central lumbar spinal stenosis with bilateral lower extremity symptoms between October 2015 and December 2017 was performed. Among them, 36 cases underwent bilateral decompression through bilateral transforaminal approach, and 8 cases underwent bilateral decompression through unilateral transforaminal approach. There were 25 males and 19 females, the age ranged from 56 to 89 years with an average of 68.6 years. The disease duration was 5-39 months with an average of 14.5 months. Involved segments: L 3, 4 in 6 cases, L 4, 5 in 33 cases, and L 5 , S 1 in 5 cases. The dural sac cross-sectional area (DSCA) of the MRI was (66.36±8.48) mm 2 . Morphological grading (MG) classification: 29 cases of grade C, 15 cases of grade D. The visual analogue scale (VAS) score of preoperative low back pain was 2.3±1.0 and the VAS score of lower extremity pain was 7.8±1.2; the Oswestry disability index (ODI) was 77.8±7.3. Postoperative VAS scores, ODI scores, MG classification, and DSCA were recorded and compared with preoperative ones, and clinical outcomes were assessed by using the modified MacNab criteria., Results: All patients successfully underwent surgery and the wounds healed by first intention. All 44 patients were followed up 13-46 months with an average of 24.8 months. One patient developed postoperative lower extremity paralysis and 1 patient developed a dural tear. There was no infection, recurrence, or revision surgery during the follow-up. Postoperative imaging showed that the central spinal canal was enlarged and the area of the dural sac was significantly increased compared with preoperative one. The VAS score of low back pain was 2.4±0.6 and 2.5±0.8 at 1 month after operation and at last follow-up, showing no significant difference when compared with preoperative scores ( P >0.05). The VAS of lower limb pain was 2.1±0.6 and 2.0±1.1 at 1 month after operation and at last follow-up, which was significantly improved when compared with preoperative scores ( P <0.05); but no significant difference was found between at 1 month after operation and at last follow-up ( P >0.05). At last follow-up, the ODI score was 19.7±6.4, and the DSCA was (104.93±12.56) mm 2 , which was significantly improved when compared with preoperative values ( P <0.05). The MG classification was also significantly higher than preoperative one ( Z =-5.789, P =0.000). According to the modified MacNab criteria, the results were excellent in 32 cases, good in 9 cases, and fair in 3 cases, with an excellent and good rate of 93.2%., Conclusion: Percutaneous endoscopic transforaminal bilateral decompression for treating severe central lumbar spinal stenosis has the advantages of less trauma, adequate decompression, and rapid recovery. The short-term effectiveness is good.

People's understanding of lumbar spinal stenosis has become more and more comprehensive and reasonable, however, there are still many controversies about the concepts of "central lumbar canal" and "lateral lumbar spinal canal", and there is no unified standard at present. In this paper, we redefine and differentiate the two concepts. We believe that some kinds of central canal stenosis caused by bilateral recess stenosis can be completely solved by bilateral percutaneous endoscopic transforaminal discectomy. At the same time, the concept of "lumbar lateral recess" is ambiguous. We redefine it as "lateral lumbar spinal canal" and propose "West China Hospital classification" to guide surgical decision-making, which has been widely recognized and applied.

Objective: To manufacture fish swim bladder membrane material by crosslinking techniques, and to explore its physical and chemical properties and cytotoxicity., Methods: After decellularization, the swim bladders were randomly divided into two groups. The swim bladders were treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) crosslinking method, surface hole making, and freeze-drying in crosslinking group, and only surface hole making and freeze-drying in non-crosslinking group. The physical and chemical properties of the materials were observed, including microstructure by scanning electron microscopy (SEM), mechanical properties (tensile strength and breaking elongation) by universal tensile machine, hydrophilicity by contact angle measuring instrument, porosity by ethanol infiltration method, degradation performance in vitro and thermal stability test, and the components of materials by infrared spectrum analysis. Mouse fibroblasts (L929) were cultured with the extracts of two groups of materials in order to determine the cytotoxicity of materials by using cell counting kit 8 (CCK-8) method., Results: The porous structure and rough surface of materials were observed by SEM. Compared with the non-crosslinking group, the tensile stress of the crosslinking group was higher, the breaking elongation was lower, and the porosity increased, showing significant differences ( P <0.05). There was no significant difference in contact angle between the two groups ( P >0.05). The degradation was faster within the first 7 days and then tended to be smooth in the two groups. But the degradation rates of crosslinking group were significantly lower than those of non-crosslinking group ( P <0.05). Differential scanning calorimeter showed that the denaturation temperature of the crosslinking group was (75.2±1.3)℃, which was significantly higher than that of the non-crosslinking group [(68.5±0.4)℃] ( t =4.586, P =0.002). Compared with the non-crosslinking group, the crosslinking group produced new C=O bond and N-H bond, and no other new groups were introduced into the cross-linking group. CCK-8 method showed that the absorbance values of the crosslinking group and the non-crosslinking group were not significant when compared with the positive control group ( P >0.05)., Conclusion: The fish swim bladder membrane obtained by crosslinking treatment with EDC/NHS method has good physical and chemical properties, no cytotoxicity, and is expected to be used as a dura mater repair material.

Objective: To evaluate the short-term effectiveness of percutaneous endoscopic lumbar discectomy (PELD) in treatment of buttock pain associated with lumbar disc herniation., Methods: Between June 2015 and May 2016, 36 patients with buttock pain associated with lumbar disc herniation were treated with PELD. Of 36 cases, 26 were male and 10 were female, aged from 18 to 76 years (mean, 35.6 years). The disease duration ranged from 3 months to 10 years (mean, 14 months). The location of the pain was buttock in 2 cases, buttock and thigh in 6 cases, buttock and the ipsilateral lower extremity in 28 cases. Thirty-four patients had single-level lumbar disc herniation, and the involved segments were L 4, 5 in 15 cases and L 5 , S 1 in 19 cases; 2 cases had lumbar disc herniation at both L 4, 5 and L 5 , S 1 . The preoperative visual analogue scale (VAS) score of buttock pain was 6.1±1.3. VAS score was used to evaluate the degree of buttock pain at 1 month, 3 months, 6 months, and last follow-up postoperatively. The clinical outcome was assessed by the modified MacNab criteria at last follow-up., Results: All patients were successfully operated and the operation time was 27-91 minutes (mean, 51 minutes). There was no nerve root injury, dural tear, hematoma formation, or other serious complications. The hospitalization time was 3-8 days (mean, 5.3 days). All incisions healed well and no infection occurred. Patients were followed up 12-24 months (median, 16 months). MRI examination results showed that the dural sac and nerve root compression were sufficiently relieved at 3 months after operation. Patients obtained pain relief after operation. The postoperative VAS scores of buttock pain at 1 month, 3 months, 6 months, and last follow-up were 1.1±0.6, 0.9±0.3, 1.0±0.3, and 0.9±0.4 respectively, showing significant differences when compared with preoperative VAS scores ( P <0.05); there was no significant difference in VAS score between the different time points after operation ( P >0.05). At last follow-up, according to the modifed MacNab criteria, the results were excellent in 27 cases, good in 9 cases, and fair in 2 cases, and the excellent and good rate was 94.4%., Conclusion: PELD can achieve satisfactory short-term results in the treatment of buttock pain associated with lumbar disc herniation and it is a safe and effective minimally invasive surgical technique.

Objective: To analyze the treatment of Gartland type Ⅱ and Ⅲ supracondylar fracture of the humerus in children., Methods: Between January 2015 and January 2017, 45 cases of Gartland type Ⅱ and Ⅲ supracondylar fracture of the humerus were treated. There were 28 boys and 17 girls with an age of 1-13 years (mean, 5.7 years). The causes of injury included sports injury in 43 cases and falling from height in 2 cases. Fractures were classified as type Ⅱ in 12 cases and type Ⅲ in 33 cases according to Gartland classification. The time from injury to operation was 2-12 hours (mean, 4.6 hours). All fractures were treated with closed reduction first, and 12 cases of Gartland type Ⅱ fracture were successful in closed reduction; 20 cases of Gartland type Ⅲ fracture were successful in closed reduction, 11 cases with reduction failure and 2 cases with radial nerve injury underwent assisted anterior transverse approach reduction. Then percutaneous crossed Kirschner wires fixation was performed., Results: The operation time was 16-52 minutes (mean, 32 minutes). The perspective frequency was 4-17 times (mean, 6.7 times). The hospitalization time was 3-7 days (mean, 4 days). All the 45 cases were followed up 8-20 months (mean, 12 months). The ulnar nerve paralysis occurred in 3 cases of Gartland type Ⅲ fracture that were treated with closed reduction, and recovered after 1-3 months. All fractures healed after operation, and the healing time was 2-3 months. No incision infection, Volkmann muscle contracture, and other complications occurred. The elbow joint function score at 6 months after operation showed that the results of closed reduction was excellent in 16 cases, good in 12 cases, and fair in 4 cases, with the excellent and good rate of 87.5%; in which Gartland type Ⅱ fracture was excellent in 9 cases and good in 3 cases, with an excellent and good rate of 100%, and Gartland Ⅲ was excellent in 7 cases, good in 9 cases, and fair in 4 cases with an excellent and good rate of 80%. The results of assisted anterior transverse approach reduction was excellent in 7 cases, good in 5 cases, and fair in 1 case, and the excellent and good rate was 92.3%., Conclusion: Gartland type Ⅱ and Ⅲ supracondylar fractures of the humerus can be treated with closed reduction or combined with the assisted anterior transverse approach reduction, then fixed by percutaneous crossed Kirschner wire, which is operational, smaller invasive, and less radiation exposure during operation, while postoperative function is good.

Objective: To investigate the feasibility, effectiveness, and security of percutaneous endoscopic spine surgery for treatment of lumbar spine disorders with intraspinal ossification., Methods: Between July 2008 and June 2016, 96 patients with lumbar spine disorders (lumbar disc herniation or lumbar spinal stenosis) with intraspinal ossification were treated with percutaneous endoscopic spine surgery. There were 59 males and 37 females, aged from 13 to 57 years (mean, 29.5 years). The disease duration was 3-51 months (mean, 18.2 months). Fifty-one cases had trauma history. Ninety-two cases were single segmental unilateral symptom, 4 cases were bilateral symptom. The ossification property was posterior ring apophysis separation in 89 cases, and ossification of the fibrous ring or posterior longitudinal ligament in 7 cases. There were 32 cases of lateral type, 13 cases of central type, and 51 cases of mixed type. The pressure factors, such as nucleus pulposus, hyperplasia of the yellow ligament, joint capsule, or articular osteophyma, were removed under the microscope. Local anesthesia or continuous epidural anesthesia was performed in the transforaminal approach with 50 cases, and continuous epidural anesthesia or general anesthesia was performed in the interlaminar approach with 46 cases. The visual analogue scale (VAS) score was used to evaluate the degree of leg pain preoperatively and at last follow-up. The effectiveness was evaluated at last follow-up according to the modified Macnab criteria., Results: All patients were successfully operated. Via transforaminal approach, the mean operation time was 53 minutes and the mean intraoperative fluoroscopy times was 8 times; and via interlaminar approach was 58 minutes and 3 times, respectively. The mean bed rest time after operation was 6.5 hours and the mean hospitalization time was 4.7 days. All patients were followed up 6-18 months (median, 11 months). Postoperative lumbar CT scan and three-dimensional reconstruction after 3 days of operation showed that ossification tissues of 26 cases were not resected, 12 cases were resected partly, and 49 cases were resected completely. Postoperative lumbar MRI after 3 months of operation showed that spinal cord and nerve root were not compressed. At last follow-up, VAS score of leg pain was 0.7±1.1, which was significantly lower than preoperative score (5.8±1.1) ( t =1.987, P =0.025). At last follow-up, according to modified Macnab criteria, the results were excellent in 87 cases, good in 5 cases, and fair in 4 cases, and the excellent and good rate was 95.8%., Conclusion: Percutaneous endoscopic spine surgery for treatment of lumbar spine disorders with intraspinal ossification is an effective, safe, and minimal invasive alternative, and the short-term effectiveness is reliable. Accounting for the treatment of intraspinal ossification, comprehensive analysis should be made by combining clinical symptoms, imaging characteristics, and risk assessment.

Objective: To discuss the effectiveness and the safety of accurate decompression via foraminoplasty in treating lumbar lateral recess stenosis patients who accompanied by disk-flavum ligamentum space and bony lateral recess stenosis, and to analysis the short-term effectiveness of the surgical procedures., Methods: Forty-five lumbar lateral recess stenosis patients accompanied by disk-flavum ligamentum space and bony lateral recess stenosis were treated by accurate decompression via foraminoplasty between January 2013 and January 2016. There were 29 males and 16 females with a median age of 58 years (range, 42-82 years). The disease duration was 3-96 months (mean, 24.4 months). The lesion segment included L 4, 5 in 36 cases and L 5 , S 1 in 9 cases. The visual analogue scale (VAS) score of low back pain and leg pain at preoperation and last follow-up were recorded, and the modified Macnab criteria was used to evaluate the effectiveness at last follow-up. Postoperative CT and MRI were reviewed to evaluate the stability and decompression of the lumbar spine., Results: All operations were successfully completed. All the 45 patients were followed up 3-18 months (median, 11 months). Dural tear occurred in 2 cases during operation, bone graft removed into the spinal canal in 1 case, postoperative low back pain occurred in 5 cases, and there was no nerve root injury, hematoma formation, or other complications. The leg pain VAS score at last follow-up (0.6±1.2) was significantly improved when compared with preoperative score (5.7±1.4) ( t =8.981, P =0.001); and the low back pain VAS scores showed no significant difference between preoperation and last follow-up (1.5±1.3 vs. 1.7±1.4; t =0.535, P =0.585). According to the modified Macnab criteria, the results were excellent in 20 cases, good in 22 cases, fair in 2 cases, and poor in 1 case at last follow-up, and the excellent and good rate was 93.3%., Conclusion: Accurate decompression via foraminoplasty is an effective, safe, and less invasive way for treating lumbar recess stenosis patients accompanied by disk-flavum ligamentum space and bony lateral recess stenosis.

Objective: To observe the character of spino-pelvic sagittal alignment in patients with high-grade L5 isthmic spondylolisthesis, and to analyze the sagittal alignment alteration after operation., Methods: Between January 2009 and June 2014, 25 patients with high-grade L5 isthmic spondylolisthesis underwent posterior surgery, and the clinical data were retrospectively analyzed as study group. There were 14 males and 11 females with a mean age of 42.5 years (range, 20-65 years). The mean disease duration was 6 months (range, 3-12 months). According to the Meyerding evaluating system, 15 cases were rated as degree III, and 10 cases as degree IV. Eighty healthy adult volunteers were recruited simultaneously as control group. The lumbar sacral angle (LSA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA) were measured on preoperative and last follow-up standing full length lateral X-ray films. And these parameters were compared between study group (preoperative parameters) and control group. Then the patients in study group were divided into 2 subgroups according to Hresko's method: the balanced pelvis subgroup (n = 14) and unbalanced pelvis subgroup (n = 11). The sagittal parameters were compared between 2 subgroups, and the alteration of sagittal parameters before surgery and at last follow-up was analyzed in each subgroup respectively., Results: All patients in study group were followed up 18 months on average (range, 6-48 months). After surgery, spondylolisthesis was reduced from degree III to degree 0 in 12 cases and to degree I in 3 cases, and from degree IV to degree 0 in 6 cases and to degree I in 4 cases. Bone fusion was obtained in all patients at last follow-up. The preoperative PI, SS, PT, and SVA of study group were significantly greater than those of control group (P < 0.05), while the TK was significantly smaller than that of control group (P < 0.05). In the balanced pelvis subgroup, LSA, LL, and SVA at last follow-up significantly decreased while TK significantly increased when compared with preoperative ones (P < 0.05). In the unbalanced pelvis subgroup, LSA, PT, and SVA at last follow-up significantly decreased while SS, LL, and TK significantly increased when compared with preoperative ones (P < 0.05). The preoperative LSA and PT in the unbalanced pelvis subgroup were significantly greater, while SS, LL, and TK were significantly smaller than those of balanced pelvis subgroup (P < 0.05); while at last follow-up, significant differentce was found only in LSA between 2 subgroups (P < 0.05)., Conclusion: The LSA should be paid more attention in surgery to assure recovery of the sagittal balance because patients with high-grade L5 isthmic spondylolisthesis have greater PI, abnormal lumbosacral kyphosis, and sagittal imbalance.

Objective: To investigate whether miR-93-5p suppresses osteogenic differentiation of mouse mesenchymal stem cells (C3H10T1/2) by targeting Smad5, a predicted target in silicon., Methods: Smad5 3'-UTR-luciferase vector (pmiR-RB-REPORT) was constructed and dual-luciferase reporter gene assay was employed to examine the effect of miR-93-5p on Smad5 3'-UTR-luciferase activity to identify whether Smad5 was the target gene of miR-93-5p. miR-93-5p mimics (group M), miR-93-5p inhibitor (group In), miR-93-5p mimics negative control (group MC), and miR-93-5p inhibitor negative control (group InC) were transfected into the C3H10T1/2 cells, respectively, and followed by induction of osteogenic differentiation. After 48 hours, the real-time fluorescent quantitative PCR (qRT-PCR) and Western blot assays were performed to detect the relative expressions of Smad5 mRNA and protein. At 14 days, to realize the regulation role of miR-93-5p in osteogenic differentiation, the extracellular calcium deposition during the osteogenesis of C3H10T1/2 cells was tested by Alizarin red staining., Results: Dual-luciferase reporter gene assay showed that miR-93-5p could combine with Smad5 mRNA 3'-UTR specificity, and inhibited its luciferase activity (P < 0.05). After 48 hours, no significant difference was shown in the relative expression of Smad5 mRNA between group M and group MC as well as between group In and group InC by qRT-PCR assay (P > 0.05); however, the results of Western blot assay showed that the relative expression of Smad5 protein was significantly decreased in group M and increased in group In when compared with groups MC and InC (P < 0.05). At 14 days after osteogenic induction, Alizarin red staining showed that the extracellular calcium deposition of group M was obviously less than that of group MC, and it was obviously more in group In than in group InC., Conclusion: Smad5 may be the target gene of miR-93-5p. And miR-93-5p can suppress osteogenic differentiation of C3H10T1/2 cells by directly targeting Smad5.

Objective: To review the biomaterial and clinical prospects of annulus tibrosus tissue engineering., Methods: The recent literature concerning annulus fibrosus tissue engineering, including cell source, bioactive molecules, and biomaterial was extensively reviewed and summarized., Results: Mesenchymal stem cells (MSCs) is an ideal seed cells. When annulus fibrosus cells and MSCs in the ratio of 2:1 are cultured, it shows the closest mRNA expression levels of annulus fibrosus-related markers. Bioactive molecules can be divided into 4 types: growth factors, morphogens, catabolic enzyme inhibitors, and intracellular regulators. They play an active role in promoting the synthesis of extracellular matrix, and maintaining intervertebral disc homeostasis and a balance between anabolic- and catabolic process in the disc. Based on the source, biological materials can be divided into natural materials, synthetic materials, and composite materials. The mechanical properties of the annulus fibrosus is an important basis for material design. Up to now, none of these scaffold materials is accepted as the most suitable one. The selection of scaffold materials is still to be further studied. The development of novel composite biomaterials is a trend., Conclusion: The annulus fibrosus tissue engineering for the anulus fibrosus regeneration and repair will bring very broad prospects for clinical application in future.

Objective: To investigate the application and technical essentials of computer-assisted navigation in the surgical management of periacetabular fractures and pelvic fractures., Methods: Between May 2010 and May 2011, 39 patients with periacetabular or anterior and posterior pelvic ring fractures were treated by minimally invasive fixation under computer-assisted navigation and were followed up more than 2 years, and the clinical data were analyzed retrospectively. There were 21 males and 18 females, aged 15-64 years (mean, 36 years). Fractures were caused by traffic accident in 23 cases, crush injury in 6 cases, and falling from height in 10 cases. Of them, 6 cases had acetabular fractures; 6 cases had femoral neck fractures; 18 cases had dislocation of sacroiliac joint; and 15 cases had anterior pelvic ring injuries. All patients were treated with closed or limited open reduction and screw fixations assisted with navigation., Results: Eighty-nine screws were inserted during operation, including 8 in the acetabulum, 18 in the neck of the femur, 33 in the sacroiliac joint, and 30 in the symphysis pubis and pubic rami. The mean time of screw implanted was 20 minutes (range, 11-38 minutes), and the average blood loss volume was 20 mL (range, 10-50 mL). The postoperative pelvic X-ray and three dimensional CT scan showed good reduction of fractures and good position of the screws. No incision infection, neurovascular injury, or implant failure occurred. All patients were followed up 27-33 months with an average of 29.6 months. The patients could walk with full weight loading at 6-12 weeks after operation (mean, 8 weeks); at last follow-up, the patients could walk on the flat ground, stand with one leg, and squat down, and they recovered well enough to do their job and to live a normal life., Conclusion: Minimally invasive fixation under computer-assisted navigation may be an excellent method to treat some specific types of periacetabular and anterior and posterior pelvic ring fractures because it has the advantages of less trauma and blood loss, lower complication incidence, and faster recovery.

Objective: To determine the feasibility and effectiveness of percutaneous endoscopic transforaminal discectomy (PETD) for recurrent lumbar disc herniation (RLDH)., Methods: Between June 2009 and December 2011, 56 patients with RLDH underwent PETD after local anesthesia, including 30 males and 26 females, with a mean age of 50 years (range, 24-70 years). The involved segments were L3, 4 in 3 cases, L4, 5 in 34 cases, and L5-S1 in 19 cases. Of 56 patients, 48 suffered from ipsilateral re-herniation, and 8 suffered from contralateral re-herniation. All the patients had a mean pain-free interval of 5.5 years (range, 6 months to 27 years). The visual analogue scale (VAS) score for back pain was 6.18 ± 1.44 and the VAS score for leg pain was 7.66 ± 1.03. Postoperative effectiveness was assessed based on the VAS score and modified MacNab criteria., Results: The mean operation time was 60.4 minutes (range, 30-100 minutes) and the mean duration of hospital stay was 5.1 days (range, 3-6 days). All patients were followed up 28.2 months on average (range, 24-56 months). Patients obtained immediate pain relief postoperatively. The postoperative VAS scores of back and leg pain at 1 month, 3 months, 12 months, and last follow-up were significantly decreased when compared with preoperative score (P < 0.05). Based on the modified MacNab criteria, the results were excellent in 39 cases, good in 9 cases, fair in 5 cases, and poor in 3 cases at 12 months after operation, and the excellent and good rate was 85.7%. Surgery-related complications were found in 5 cases (8.9%); one patient (1.8%) suffered from recurrence at 18 months postoperatively, and the symptom was relieved after open lumbar discectomy and intervertebral fusion surgery., Conclusion: PETD has several advantages in treating RLDH, such as avoiding from the old scar tissue, decreasing operation-related complications, shortening operation time, reducing trauma, and obtaining rapid postoperative recovery. This technique is feasible and effective for RLDH.

Objective: To review the mechanism and research progress of signaling pathways which play key roles in the regulation of osteoblast differentiation and bone formation., Methods: Recent articles about signaling pathways of osteoblast differentiation and bone formation were reviewed and comprehensively analyzed., Results: At present, multiple signaling pathways have been found to be involved in the regulation of osteoblast differentiation and bone formation, among which bone morphogenetic protein-Smads, Wnt/β-catenin, Notch, Hedgehog, and fibroblast growth factor signaling pathways may play the most important roles. Not only each pathway has a complex regulatory mechanism itself, but also contacts and impacts with each other, thus they formed a more complicated and sophisticated regulatory network, and regulate together osteoblast differentiation and bone formation. However, the mechanisms in detail of those pathways are still not very clear, because the animal experiment techniques are not yet mature as well as the relevant clinical trials were carried out not too much., Conclusion: The complete molecular mechanism of osteoblast differentiation and bone formation should be further investigated, so as to lay a theory foundation for preventing and treating the common bone diseases in clinical which are involve in osteoblast differentiation and bone formation.

Objective: To investigate the feasibility and short-term effectiveness of percutaneous endoscopic spine surgery for treatment of lumbar disc herniation with posterior ring apophysis separation., Methods: Between July 2008 and January 2013, 57 patients with lumbar disc herniation and posterior ring apophysis separation were treated. There were 39 males and 18 females, aged from 13 to 46 years (mean, 26.7 years). Of 57 cases, 29 had a clear trauma history. All patients had single segmental unilateral lumbar disc herniation, and the location was at L4, 5 in 22 cases and at L5, S1 in 35 cases; there were 25 cases of lateral bone fragments and 32 cases of central cortical and cancellous fragments. While fracture located at posterior inferior edge of the vertebrae at L4 level in 9 cases and at Ls level in 8 cases, at posterior superior edge at L5 level in 13 cases and in S1 level in 27 cases. Percutaneous endoscopic surgeries were performed via interlaminar or transforaminal approach from unilaterally symptomatic side for discectomy of lumbar disc herniation and partial or complete resection of free bone fragments., Results: Accurate positioning was obtained in all patients during operation, and no complication of nerve root injury, hematoma formation, or dural tear occurred. The operation time was 20-85 minutes; the intraoperative fluoroscopy times were 2-15 times, and the blood loss was 3-10 mL. Postoperative radiographic examination showed that bone fragment was not removed in 16 cases, was partly removed in 32 cases, and was completely removed in 9 cases. Disc was completely removed. All patients were followed up 10-64 months (median, 16 months). According to modified Macnab criteria for the evaluation of effectiveness, the results were excellent in 48 cases, good in 6 cases, and fair in 3 cases, and the excellent and good rate was 94.7%., Conclusion: Percutaneous endoscopic spine surgery through unilaterally symptomatic approach has advantages of small tissue damage and lumbar structure damage, less bleeding, and shorter recovery time. It has a good short-term effectiveness, but long-term effectiveness need further follow-up.

Objective: To investigate the specific microRNA (miRNA) in osteogenic and chondrogenic differentiations of C3H10Tl/2 cells., Methods: C3H10Tl/2 cells were induced to differentiate into osteoblasts and chondrocytes. Specific miRNA more than 2 fold change and 2 average normalized probe signal between C3H10Tl/2 and C3H10Tl/2-derived osteoblast, and' between C3Hl0Tl/2 and C3H10Tl/2-derived chondrocytes were screened out by miRNA microarray, and verified by real-time fluorescence quantitative PCR (RT-qPCR)., Results: Alkaline phosphatase expression of osteogenic induced group was significantly higher than that of control group at 7 days after induced (P < 0.05). RT-qPCR results showed the expressions of Runx2, serine protease (Sp7), collagen type I, and osteopontin (OPN) genes were significantly increased at 7, 14, and 21 days after induced when compared with before induced (P < 0.05). Western blot results showed the expressions of Runx2, Sp7, collagen type I, and OPN proteins of osteogenic induced group were significantly higher than those of control group at 21 days after induced (P < 0.05). The expressions of SOX9, collagen type II, Aggrecan, and Has2 were significantly increased at 5, 10, and 15 days after induced when compared with before induced (P < 0.05). The expressions of SOX9, collagen type 2, Aggrecan, and Has2 proteins of chondrogenic induced group were significantly higher than those of control group at 15 days after induced (P < 0.05). Totally, 10 osteogenic and 3 chondrogenic miRNA more than 2 fold change and 2 average normalized probe signal were screened out by miRNA microarray. RT-qPCR results of these specific miRNAs were similar to microarray results except miR-455-3p., Conclusion: Specific miRNAs are screened out by microarray and it is a good foundation for the future study on miRNA functional verification and target gene prediction.

Objective: To investigate the influence of Nogo extracellular peptide residues 1-40 (NEP1-40) gene modification on the survival and differentiation of the neural stem cells (NSCs) after transplantation., Methods: NSCs were isolated from the cortex tissue of rat embryo at the age of 18 days and identified by Nestin immunofluorescence. The lentiviruses were transduced to NSCs to construct NEP1-40 gene modified NSCs. The spinal cords of 30 Sprague Dawley rats were hemisected at T9 level. The rats were randomly assigned to 3 groups: group B (spinal cord injury, SCI), group C (NSCs), and group D (NEP1-40 gene modified NSCs). Cell culture medium, NSCs, and NEP1-40 gene modified NSCs were transplanted into the lesion site in groups B, C, and D, respectively at 7 days after injury. An additional 10 rats served as sham-operation group (group A), which only received laminectomy. At 8 weeks of transplantation, the survival and differentiation of transplanted cells were detected with counting neurofilament 200 (NF-200), glial fibrillary acidic portein (GFAP), and myelin basic protein (MBP) positive cells via immunohistochemical method; the quantity of horseradish peroxidase (HRP) positive nerve fiber was detected via HRP neural tracer technology., Results: At 8 weeks after transplantation, HRP nerve trace showed the number of HRP-positive nerve fibers of group A (85.17 +/- 6.97) was significantly more than that of group D (59.25 +/- 7.75), group C (33.58 +/- 5.47), and group B (12.17 +/- 2.79) (P < 0.01); the number of groups C and D were significantly higher than that of group B, and the number of group D was significantly higher than that of group C (P < 0.01). Immunofluorescent staining for Nestin showed no obvious fluorescence signal in group A, a few scattered fluorescent signal in group B, and strong fluorescence signal in groups C and D. The number of NF-200-positive cells and MBP integral absorbance value from high to low can be arranged as an order of group A, group D, group C, and group B (P < 0.05); the order of GFAP-positive cells from high to low was group B, group D, group C, and group A (P < 0.05); no significant difference was found in the percentage of NF-200, MBP, and GFAP-positive cells between group C and group D (P > 0.05)., Conclusion: NEP1-40 gene modification can significantly improve the survival and differentiation of NSCs after transplantation, but has no induction on cell differentiation. It can provide a new idea and reliable experimental base for the study of NSCs transplantation for SCI.

Objective: To investigate the effect of the penetration of mini-plate mass screws into facet joint on axial symptoms in cervical laminoplasty., Methods: A retrospective analysis was made on the clinical data of 52 patients who underwent unilateral open-door cervical expansive laminoplasty fixed with Centerpiece mini-plate between September 2009 and December 2011. There were 42 males and 10 females, with a mean age of 61.2 years (range, 34-83 years). Seventeen patients exhibited simple degeneration cervical canal stenosis, 25 patients had multilevel cervical disc protrusion, and 10 patients had ossification of posterior longitudinal ligaments. Disease duration ranged 1-120 months (median, 11 months). The Japanese Orthopedic Association (JOA) score was used to assess neurological function, and JOA recovery rates were calculated. The visual analogue score (VAS) and the neck disability index (NDI) were used to evaluate the axial pain and neck daily activities. The axial symptoms and other complications were recorded. The cervical canal diameter, cervical curvature, cervical canal cross area, and open angle were measured according to the X-ray films, CT scans, and MRI scans. The postoperative CT three dimensional (3-D) reconstruction images were used to identify whether the screws penetrated into the facet joints. All the patients were divided into 3 groups according to involved facet joints: no joint penetrating group (no penetrated facet joint), oligo-joint penetrating group (one or two penetrated facet joints), and multi-joint penetrating group (three or more penetrated facet joints)., Results: Five patients suffered from C5 nerve palsy, and 2 patients had cerebrospinal fluid leakage. The follow-up time ranged 3-35 months (mean, 15.7 months). At the final follow-up, the JOA scores, NDI, cervical canal diameter, and cervical canal cross area were significantly improved when compared with preoperative ones (P < 0.05). At 1 week after operation, CT 3-D reconstruction showed that 16 patients had no penetrated facet joint, 23 patients had one or two penetrated facet joints, and 13 patients had three or more penetrated facet joints. There was no significant difference in age, gender, disease duration, operation time, intraoperative blood loss, and follow-up time among 3 groups (P > 0.05). And at the final follow-up, there was no significant difference in JOA score, VAS score, cervical curvature, cervical canal diameter, cervical canal cross area, the JOA recovery rates, and lamiae open angle among 3 groups (P > 0.05). The NDI of the multi-joint penetrated group was significantly higher than that of other 2 groups (P < 0.05). Axial pain occurred in 1 case of no penetrating group, in 4 cases of oligo-joint penetrating group, and in 5 cases of multi-joint penetrating group, showing no significant difference among 3 groups (Chi(2)=4.881, P=0.087)., Conclusion: The penetrations of lateral mass screws into articular surface of facet joint may contribute to the axial symptoms after cervical laminoplasty. The risk of axial symptom raises accompany with increased penetrated facet joints.

Objective: To determine the surgical indications for posterior expansive open-door laminoplasty (EOLP) extended to the C1 level., Methods: Seventeen patients undergoing C3-7 or C2-7 open-door laminoplasty were included as the case group between September 2005 and January 2010, whose spinal cord injury symptoms were not alleviated or aggravated again because of the cervical stenosis at C-4 level, and the causes of the surgery itself were eliminated, all of these patients underwent reoperation with decompress upward to C1 level. Fifteen patients with cervical stenosis who underwent C2-7 laminoplasty and C1 laminectomy were selected as the control group. There was no significant difference in gender, age, and disease duration between 2 groups (P > 0.05). The pre- and post-operative cervical curvature and spinal cord compression were evaluated according to the patients' imaging data; the pre- and post-operative neurological recovery situation was evaluated by Japanese Orthopaedic Association (JOA) 17 score and spinal cord function Frankel grade; the neurological recovery rate (according to Hirabayashi et al. method) was used to assess the postoperative neurological recovery situation., Results: In the case group, 8 patients underwent primary C37 laminoplasty. In 3 of these patients, there was a cervical stenosis at C1, 2 level, and discontinuous cerebrospinal fluid around the spinal cord was observed; 5 of them with a compression mass which diameter was exceed 7.0 mm in the C2-4 segments. The remaining 9 patients in the case group underwent primary C2-7 laminoplasty, and the diameter of the compression mass was exceed 7.0 mm in the C2-4 segments. In all 17 patients of the case group, reoperation was performed with the decompression range extended to the C1 level, and the follow-up time was 35-61 months with an average of 45.6 months. Cervical curvature: there were 11 cases of cervical lordosis, 4 cases of straight spine, and 2 cases of cervical kyphosis before operation; but after operation, 2 cases of cervical lordosis became straight spine and 1 straight case became kyphosis. The postoperative neurological improvement was excellent in 8 cases, good in 7, and fair in 2. In the control group, all the patients had a compression mass which anteroposterior diameter was exceed 7.0 mm in the C2-4 segments before operation. The follow-up time was 30-58 months with an average of 38.7 months. Cervical curvature: there were 13 cases of cervical lordosis and 2 cases of straight spine before operation; but after operation, 1 case of cervical lordosis became straight spine. The postoperative neurological improvement was excellent in 8 cases, good in 6, and fair in 1. No significant difference was found in the JOA score at pre- and post-operation between 2 groups (P > 0.05); however, there were significant differences (P < 0.05) in the JOA score between at last follow-up and at preoperation., Conclusion: The initially surgical indications which can be used as a reference for EOLP extended to C1 are as follows: (1) Upper cervical (C1, 2) spinal stenosis: C1 posterior arch above the lower edge part of cerebrospinal fluid around the spinal cord signal is not continuous, and the anteroposterior diameter of the spinal canal actual is less than 8.0 mm as judgment standard. (2) There is a huge compression at the lower edge of C2-4 vertebrae, and the most prominent part of the diameter is exceed 7.0 mm, which can not be removed through the anterior cervical surgery, or the operation is high-risk.

Objective: To review the research progress of the risk factors for slip progression and the pathogenesis of lumbosacral spondylolisthesis, and to discuss the value of Spinal Deformity Study Group (SDSG) classification system for lumbosacral spondylolisthesis., Methods: Recent articles about the risk factors for slip progression and the pathogenesis of lumbosacral spondylolisthesis were reviewed and comprehensively analyzed with SDSG classification system of lumbosacral spondylolisthesis., Results: Pelvic incidence (PI) is the key pathogenic factor oflumbosacral spondylolisthesis. The Meyerding grade of slip, PI, sacro-pelvic balance, and spino-pelvic balance not only are the fundamental risk factors of slip progression, but also are the key factors to determine how to treat and influence the prognosis. Therefore, compared with Wiltse, Marchetti-Bartolozzi, and Mac-Thiong-Labelle classification systems oflumbosacral spondylolisthesis, SDSG classification based on these factors mentioned above, has better homogeneity between the subjects of subgroup, and better reliability, moreover, could better guide operative plan and judge the prognosis., Conclusion: It is suggested that the SDSG classification system should be the standard classification for lumbosacral spondylolisthesis for the clinical and research work.

Objective: To analyze the clinical features and preliminary outcome of posterior operation for traumatic lumbar spondylolisthesis., Methods: The clinical data of 11 patients with traumatic lumbar spondylolisthesis who underwent surgeries between January 2008 and June 2012 were retrospectively analyzed. There were 6 male and 5 female patients, aged from 13 to 60 years with a median age of 38 years. The mechanism of injury included heavy pressure injury in 4 cases, falling injury from height in 4 cases, and traffic accident injury in 3 cases. The time of injury to operation was between 3 days and 13 years (median, 20 days). According to Frankel neurological function grading, 2 patients were rated as grade E, 4 as grade D, 3 as grade C, and 2 as grade B before operation; according to Meyerding spondylolisthesis grading, 4 cases were classified as degree I, 4 as degree II, 2 as degree III, and 1 as degree IV preoperatively. The affected segments included L4 in 3 and L5 in 8 patients. The surgical fixation segments were L4, 5 in 2 patients, L5, S1 in 7, and L4-S1 in 2. Eight patients underwent circumferential fusion, while 3 patients underwent posterolateral fusion. The reduction of spondylolisthesis and bone graft fusion were assessed on X-ray films and three-dimensional CT scans during follow-up. The clinical outcomes were evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI) scores., Results: All patients achieved primary healing of incision after operation. And all patients were followed up 6-40 months with a median time of 12 months. There was no pulling-out or breaking of internal fixation. The fusion rate was 100% on three-dimensional CT scans, and the fusion time was 3-6 months (mean, 4.5 months). The spondylolisthesis was degree 0 in 10 cases and degree I in 1 case according to Meyerding grading, showing significant difference when compared with preoperative spondylolisthesis grading (Z = -2.979, P = 0.003). The Frankel neurological function grading were E in 6, D in 3, and C in 2 at last follow-up, which were significantly improved when compared with preoperative one (Z = -2.271, P = 0.014). At 1 week after operation and last follow-up, VAS and ODI scores were significantly improved when compared with the preoperative scores (P < 0.05); however, no significant difference was found between at 1 week and at last follow-up (P > 0.05)., Conclusion: If lumbar X-ray films suggest multiple fractures of transverses in emergency combined with the mechanism of injury, it strongly indicates the diagnosis of traumatic lumbar spondylolisthesis, moreover earlier decompression and fusion can provide the recovering of the neurological function and satisfactory preliminary effectiveness in these patients.

Objective: To compare the rib regeneration in patients with adolescent idiopathic scoliosis (AIS) after convex short length rib resection or conventional thoracoplasty., Methods: Between January 2005 and December 2009, 36 patients with Lenke 1 AIS underwent posterior correction, instrumentation, and fusion, and the clinical data were retrospectively analyzed. Conventional thoracoplasty was performed in group A (n=14), convex short length rib resection in group B (n=22). There was no significant difference in gender, age, Cobb angle of major curve, flexibility, and preoperative rib hump between 2 groups (P > 0.05). The standing long-cassette anteroposterior and lateral X-ray films of spine were taken at 3 months, 6 months, 1 year, and 2 years respectively after operation. Rib regeneration classification established by Philips was used to analyze the rib formation., Results: All patients were followed up 32 months on average (range, 24-48 months). Cobb angle of major curve and rib hump were significantly improved when compared with preoperative values in 2 groups (P < 0.05), and there was no obvious correction loss. At each time point after operation, there was no significant difference in Cobb angle of major curve between 2 groups (P > 0.05), but the rib humb of group B was significantly bigger than that of group A (P < 0.05). The rib regeneration in group B was better than that in group A, showing significant difference (P < 0.05). At 3 months after operation, 80.0% rib regeneration was below grade 4 in group A, and 96.3% rib regeneration reached grade 4 or above in group B. At 2 years after operation, 52.0% and 96.3% rib regeneration reached grade 6 or above in groups A and B, respectively., Conclusion: The rib regeneration in patients with AIS after convex short length rib resection is better than that after conventional thoracoplasty.

Objective: To evaluate the application of artificial lamina of multi-amino-acid copolymer (MAACP)/nano-hydroxyapatite (n-HA) in prevention of epidural adhesion and compression of scar tissue after posterior cervical laminectomy., Methods: Fifteen 2-year-old male goats [weighing, (30 +/- 2) kg] were randomly divided into experimental group (n=9) and control group (n=6). In the experimental group, C4 laminectomy was performed, followed by MAACP/n-HA artificial lamina implantations; in the control group, only C4 laminectomy was performed. At 4, 12, and 24 weeks after operation, 2, 2, and 5 goats in the experimental group and 2, 2, and 2 goats in the control group were selected for observation of wound infection, artificial laminar fragmentation and displacement, and its shape; Rydell's degree of adhesion criteria was used to evaluate the adhesion degree between 2 groups. X-ray and CT images were observed; at 24 weeks after operation, CT scan was used to measure the spinal canal area and the sagittal diameter of C3, C4, and C5 vertebrea, 2 normal goats served as normal group; and MRI was used to assess adhesion and compression of scar tissue on the dura and the nerve root. Then goats were sacrificed and histological observation was carried out., Results: After operation, the wound healed well; no toxicity or elimination reaction was observed. According to Rydell's degree of adhesion criteria, adhesion in the experimental group was significantly slighter than that in the control group (Z= -2.52, P=0.00). X-ray and CT scan showed that no dislocation of artificial lamina occurred, new cervical bone formed in the defect, and bony spinal canal was rebuilt in the experimental group. Defects of C4 vertebral plate and spinous process were observed in the control group. At 24 weeks, the spinal canal area and sagittal diameter of C4 in the experimental group and normal group were significantly larger than those in the control group (P < 0.05), but no significant difference was found between experimental group and normal group (P > 0.05). MRI showed cerebrospinal fluid signal was unobstructed and no soft tissue projected into the spinal canal in the experimental group; scar tissue projected into the spinal canal and the dura were compressed by scar tissue in the control group. HE staining and Masson trichrome staining showed that artificial lamina had no obvious degradation with high integrity, some new bone formed at interface between the artificial material and bone in the experimental group; fibrous tissue grew into defect in the control group., Conclusion: The MAACP/n-HA artificial lamina could maintaine good biomechanical properties for a long time in vivo and could effectively prevent the epidural scar from growing in the lamina defect area.

Objective: To investigate the technique of reduction by posterior approach for severe spondylolisthesis, and to discuss the method to prevent nerve stretch injury., Methods: Between July 2007 and April 2011, 17 patients with severe spondylolisthesis underwent reduction, fixation, and fusion by posterior approach. There were 2 males and 15 females with a median age of 15 years (range, 8-67 years) and a median disease duration of 18 months (range, 5 months-16 years and 4 months). The level of spondylolisthesis was at L4 in 1 case and Ls in 16 cases; the spondylolisthesis was at degree III in 12 cases and degree IV in 5 cases according to Meyerding classification. There were 16 cases of developmental spondylolisthesis (high-dysplastic and low-dysplasia spondylolisthesis in 9 and 7 cases, respectively) and 1 case of traumatic spondylolisthesis; 16 cases of developmental spondylolisthesis at L5 level included 6 cases of type 4, 9 case of type 5, and 1 case of type 6 according to Spinal Deformity Study Group (SDSG) classification. All cases underwent posterior spinal decompression, Schanz screw fixation for the slipped vertebrae, the intervertebral and posterolateral fusion and reduction of the slipped vertebrae, and correction of the lumbosacral kyphosis. The reductive degree of slipped vertebrae was modulated according to the strain of exiting spinal root. The slip degree should be reduced within Meyerding degree II. The anteroposterior and lateral radiographs of whole spine were taken in a standardized standing position to observe the correction of displacement severity and lumbosacral angle. The nerve function and pain score of lower extremity were evaluated by neurological Frankel grade and visual analogue scale (VAS). Bony fusion was assessed by followed-up CT three-dimentional reconstruction. Results Exiting nerve root paralysis occurred in 1 case after operation, and released at 4 weeks after operation; no aggravation of nerve damage was observed in the other patients. The incisions primarily healed. All the patients were followed up 12-48 months (mean, 25 months). The slip percentage, the lumbosacral angle, and VAS score of lower extremity were improved from 72% +/- 10%, (18.2 +/- 3.5) degrees, and 7.0 +/-1.5 at preoperation to 12% +/- 6%, (-7.3 +/- 2.9) degrees , and 1.5 + 1.3 at 12 months after operation respectively, all showing significant differences (P < 0.05). Osteosynthesis was seen at the bone grafting area by CT three-dimentional reconstruction at 12 months after operation. No breakage of screw and rod or reduction loss occurred., Conclusion: It can obtain satisfactory clinical result to use spinal canal decompression by posterior approach, the Schanz screw fixation of the slipped vertebrae, the intervertebral and posterolateral fusion for severe spondylolisthesis. The risk of nerve stretch injury can be prevented by choosing the lowest height of intervertebral cage, modulating the reductive degree of slipped vertebrae according to the strain of exiting spinal root, and correcting lumbosacral kyphosis.

Objective: To investigate the effectiveness of posterior intrasegmental fixation with pedicle screw-lamina hook system and bone grafting for lumbar spondylolysis., Methods: Between January 2005 and October 2009, 22 patients with lumbar spondylolysis underwent posterior intrasegmental fixation with pedicle screw-lamina hook system and bone grafting. There were 19 males and 3 females with an average age of 18.4 years (range, 12-26 years). The main symptom was low back pain with an average disease duration of 16 months (range, 8-56 months). The visual analogue scale (VAS) was 6.0 +/- 1.2 and Oswestry disability index (ODI) was 72.0% +/- 10.0% preoperatively. The X-ray films showed bilateral spondylolysis at L4 in 9 cases and at L5 in 13 cases. The range of motion (ROM) at upper and lower intervertebral spaces was (11.8 +/- 2.8) degrees and (14.1 +/- 1.9) degrees, respectively., Results: All incisions healed by first intention. All patients were followed up 12-45 months (mean, 25 months). Low back pain was significantly alleviated after operation. The VAS score (0.3 +/- 0.5) and ODI (17.6% +/- 3.4%) were significantly decreased at last follow-up when compared with preoperative scores (P < 0.05). CT showed bone graft fusion in the area of isthmus defects, with no loosening or breaking of internal fixator. At last follow-up, the lateral flexion-extension X-ray films of the lumbar spine showed that the ROM at upper and lower intervertebral spaces was (12.3 +/- 2.1) degrees and (13.5 +/- 1.7) degrees, respectively; showing significant differences when compared with preoperative values (P < 0.05). Pain at donor site of iliac bone occurred in 1 case, and was cured after pain release treatment., Conclusion: The posterior intrasegmental fixation with pedicle screw-lamina hook system and bone grafting is a reliable treatment for lumbar spondylolysis, having a high fusion rate, low complication rate, and maximum retention of lumbar ROM.

Objective: To compare the short-term effectiveness of minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF) versus open-TLIF in treatment of single-level lumbar degenerative disease., Methods: Between February 2010 and February 2011, 147 patients with single-level lumbar degenerative diseases underwent open-TLIF in 104 cases (open-TLIF group) and MIS-TLIF in 43 cases (MIS-TLIF group), and the clinical data were analyzed retrospectively. There was no significant difference in gender, age, disease type, lesion level, disease duration, preoperative visual analogue scale (VAS), and preoperative Oswestry disability index (ODI) between 2 groups (P > 0.05). The operation time, intraoperative radiological exposure time, intra- and post-operative blood loss, postoperative hospitalization time, and postoperative complications were compared between 2 groups. The VAS score and ODI were observed during follow-up. The imaging examination was done to observe the bone graft fusion and the locations of internal fixator and Cage., Results: There was no significant difference in operation time between 2 groups (t = 0.402, P = 0.688); MIS-TLIF group had a decreased intra- and post-operative blood loss, shortened postoperative hospitalization time, and increased intraoperative radiological exposure time, showing significant differences when compared with open-TLIF group (P < 0.05). Cerebrospinal fluid leakage (2 cases) and superficial infection of incision (2 cases) occurred after operation in open-TLIF group, with a complication incidence of 3.8% (4/104); dorsal root ganglion stimulation symptom (3 cases) occurred in MIS-TLIF group, with a complication incidence of 7.0% (3/43); there was no significant difference in the complication incidence between 2 groups (chi2 = 0.657, P = 0.417). The patients were followed up 18-26 months (mean, 21 months) in MIS-TLIF group, and 18-28 months (mean, 23 months) in open-TLIF group. The VAS scores and ODI of 2 groups at each time point after operation were significantly improved when compared with those before operation (P < 0.05). There was no significant difference in VAS score between 2 groups at discharge and 3 months after operation (P > 0.05); VAS score of MIS-TLIF group was significantly lower than that of open-TLIF group at last follow-up (t = 2.022, P = 0.047). At 3 months and last follow-up, no significant difference was found in the ODI between 2 groups (P > 0.05). The imaging examination showed good positions of Cage and internal fixator, and bone graft fusion in 2 groups., Conclusion: The shortterm effectiveness of MIS-TLIF and open-TLIF for single-level degenerative lumbar diseases was similar. MIS-TLIF has the advantages of less invasion and quick recovery, but the long-term effectiveness needs more observation.

Objective: To discuss the surgical selection and effectiveness for patients with recurrent giant cell tumor of bone., Methods: Between February 1988 and June 2007, 79 patients with recurrent giant cell tumor of bone were treated. There were 42 males and 37 females, with a mean age of 33.1 years (range, 15-72 years). In primary surgery, 76 patients underwent intralesional curettage, and the other 3 patients underwent resection; the recurrence time was 2-176 months after primary surgery. The locations of tumor were upper extremities in 14 cases and lower extremities in 65 cases. According to Companacci grade, 1 case was at grade I, 33 cases at grade II, and 45 cases at grade III before primary surgery. In secondary operation, 37 patients underwent intralesional curettage and bone grafting combined with adjuvant inactivated, and 42 patients underwent wide resection., Results: Bone allograft immune rejection occurred in 2 cases, which led to poor healing; primary healing of incision was obtained in the other patients. The patients were followed up 68 months on average (range, 18-221 months). Recurrence occurred in 12 patients at 6-32 months after operation. The re-recurrence rate was 24.3% (9/37) in cases of intralesional curettage and bone grafting combined with adjuvant inactivated, and they were given the wide resection. The re-recurrence rate was 7.1% (3/42) in cases of wide resection and they were amputated. There was significant difference in the re-recurrence rate between the intralesional curettage and the wide resection (chi2 = 4.508, P = 0.034). No recurrence was observed during 3-year follow-up among re-recurrence patients., Conclusion: For benign recurrent giant cell tumor of bone, intralesional curettage and bone grafting combined with adjunctive therapy could get an acceptable effectiveness, however, it has higher local recurrence than wide resection. For large tumor and recurrent malignant giant cell tumor of bone, wide resection is recommended.

Objective: To evaluate the short-term effectiveness of nano-hydroxyapatite/polyamide-66 (n-HA/PA66) intervertebral cage for lumbar interbody fusion in the patients with lower lumbar degenerative diseases., Methods: Between January and October 2011, 20 patients with lower lumbar degenerative diseases underwent transforaminal lumbar interbody fusion with n-HA/PA66 intervertebral cage. There were 8 males and 12 females, aged 22-80 years (mean, 51 years). The disease duration was 1 to 24 months (mean, 4 months). L4,5 fusion was performed in 8 cases, L5, S1 fusion in 9 cases, and L4-S1 fusion in 3 cases. Among 20 cases, 3 were diagnosed as having recurrent lumbar disc protrusion, 5 as having lumbar degenerative spondylolisthesis, 9 as having lumbar isthmic spondylolisthesis, and 3 as having lumbar spinal stenosis. The intervertebral height and lordosis were measured on X-ray film to assess the surgical correction and postoperative sustain while osseous fusion was observed on 3-dimensional CT. The Oswestry disability index (ODI) and short-form 36 health survey scale (SF-36) scores were obtained to assess the status of clinical recovery., Results: All patients had incision healing by first intention. The pain and numb were relieved in varying degrees after operation. No cerebrospinal leakage, nerve root injury, or wound infection was occurred. All patients were followed up 6-9 months (mean, 7 months). No cage displacement or collapse was found. The intervertebral height and lordosis of single fusion segment were significantly improved at 3 days and 3, 6 months after operation when compared with those at preoperation (P < 0.01); there was no significant difference among each time point after operation (P > 0.05). The fusion rate was 74% at 3 months after operation and 96% at 6 months after operation, with an average of 4 months (range, 3-9 months) for interbody fusion. The ODI and SF-36 scores were significantly improved at 3 days and 6 months after operation when compared with the scores at preoperation (P < 0.01); there was no significant difference among each time point after operation (P > 0.05)., Conclusion: The interbody fusion with n-HA/PA intervertebral cage is effective and safe to treat the lower lumbar degenerative diseases. The n-HA/PA66 intervertebral cage is an ideal device of interbody fusion with high fusion rate, low subsidence rate, and high transmission X-ray, but the long-term effectiveness need further observation.

Objective: To evaluate the early clinical outcomes of subtotal corpectomy and intervertebral bone grafting through posterior approach alone in the treatment of thoracolumbar burst fracture or thoracolumbar fracture-dislocation., Methods: Between January 2009 and December 2010, 20 patients with thoracolumbar burst fracture or thoracolumbar fracture dislocation were treated with subtotal corpectomy and intervertebral bone grafting through posterior approach alone. There were 14 males and 6 females, with an average age of 36.1 years (range, 19-47 years). Fractures were caused by falling from height in 12 cases, traffic accident in 6 cases, and crushing in 2 cases. According to AO classification, there were 10 cases of A3 type, 8 cases of B2 type, and 2 cases of C2 type. Single segment was involved in 8 cases, double segments in 12 cases. Twelve cases complicated by fracture dislocation and 6 cases by lateral displacement. All patients had bones occupancy in vertebral canal. The preoperative Cobb angle was (30.2 +/- 3.9) degrees. According to Frankel classification for neurological function, there were 4 cases of grade B, 9 cases of grade C, and 7 cases of grade D at preoperation. The mean time between injury and operation was 4.5 days (range, 1-12 days)., Results: All incisions healed by first intention, and no infection occurred. Twenty patients were followed up 8-16 months (mean, 12 months). The interbody fusion time was 6-9 months (mean, 7 months). Neurological function recovered 1 to 3 grades: 1 case of grade C, 2 cases of grade D, 17 cases of grade E at last follow-up. The Cobb angle was (6.5 +/- 4.2) degrees at last follow-up, showing significant difference when compared with preoperative value (t = 2.39, P = 0.00). No breaking or loosening of screw and implant sinkage occurred., Conclusion: A combination of subtotal corpectomy and intervertebral bone grafting through posterior approach alone has the advantages of complete decompression, restoration of spinal stability, restoration of vertebral body height, high bone healing rate, and good recovery of neurological function. However, this surgical technique has a relatively large amount of blood loss and high requirements for surgeons.

Objective: To review the progress in the research of complications after expansive laminoplasty such as axial symptom, kyphotic deformity, and segmental motor paralysis., Methods: Recent articles about complications after expansive laminoplasty were reviewed, and comprehensive analysis was done., Results: The pathogenesis of axial symptom, kyphotic deformity, and segmental motor paralysis has not yet fully been understood, but has brought new finding, such as the importance of the spinous process-ligament-muscle complex, C5 palsy theory, and the involvement of the spinal cord mechanism., Conclusion: The pathogenesis of axial symptom, kyphotic deformity, and segmental motor paralysis should be further investigated to prevent and treat the complications.

Objective: To study the effectiveness of computer assisted pedicle screw insertion in osteoporotic spinal posterior fixation., Methods: Between December 2009 and March 2011, 51 patients underwent pedicle screw fixation using the computer assisted navigation (navigation group), while 41 patients underwent the conventional technique (traditional group). All patients had osteoporosis under the dual-energy X-rays absorptiometry. There was no significant difference in age, gender, bone mineral density, involved segment, preoperative complications, and other general status between 2 groups (P > 0.05). The amount of blood loss, the operation time, the rate of the pedicle screw re-insertion, and the postoperative complication were observed. The state of the pedicle screw location was assessed by CT postoperatively with the Richter's classification and the fusion state of the bone graft was observed using three-dimensional (3-D) CT scans during follow-up., Results: A total of 250 screws were inserted in navigation group, and 239 were inserted successfully at first time while the other 11 screws (4.4%) were re-inserted. A total of 213 screws were inserted in traditional group, and 190 were successful at first time while 23 screws (10.8%) were re-inserted. There was significant difference in the rate of screws re-insertion between 2 groups (chi2 = 6.919, P = 0.009). Both the amount of blood loss and the operation time in navigation group were significantly less than those in traditional group (P < 0.05). According to Richter's classification for screw location, the results were excellent in 240 screws, good in 10 screws in navigation group; the results were excellent in 191 screws, good in 21 screws, and poor in 1 screw in traditional group. Significant difference was noticed in the screw position between 2 groups (chi2 = 7.566, P = 0.023). The patients were followed up (7.8 +/- 1.5) months in navigation group and (8.7 +/- 1.5) months in traditional group. No loosening, extraction, and breakage of the pedicle screw occurred in navigation group, and all these patients had successful fusion within 6 months postoperatively. While in traditional group, successful fusion was shown in the other patients by 3-D CT, except the absorption of bone graft was found in only 1 patient at 6 months after operation. And then, after braking by adequate brace and enhancing the anti-osteoporotic therapy, the bone graft fused at 9 months postoperatively., Conclusion: The computer assisted navigating pedicle screw insertion could effective reduce the deviation or re-insertion of the screws, insuring the maximum stability of each screw, mean while it can reduce the exposure time and blood loss, avoiding complication. The computer assisted navigation would be a useful technique which made the pedicle screw fixation more safe and stable in patients with osteoporosis.

Objective: To construct a lentiviral expression vector carrying Nogo extra cellular peptide residues 1-40 (NEP1-40) and to obtain NEP1-40 efficient and stable expression in mammalian cells., Methods: The DNA fragment of NEP1-40 coding sequence was amplified by PCR with designed primer from the cDNA library including NEP1-40 gene, and then subcloned into pGC-FU vector with in-fusion technique to generate the lentiviral expression vector, pGC-FU-NEP1-40. The positive clones were screened by PCR and the correct NEP1-40 was confirmed by sequencing. Recombinant lentiviruses were produced in 293T cells after the cotransfection of pGC-FU-NEP1-40, and packaging plasmids of pHelper 1.0 and pHelper 2.0. Green fluorescent protein (GFP) expression of infected 293T cells was observed to evaluate gene delivery efficiency. NEP1-40 protein expression in 293T cells was detected by Western blot., Results: The lentiviral expression vector carrying NEP1-40 was successfully constructed by GFP observation, and NEP1-40 protein expression was detected in 293T cells by Western blot., Conclusion: The recombinant lentivirus pGC-FU-NEP1-40 is successfully constructed and it lays a foundation for further molecular function study of NEP 1-40.

Objective: To review the research progress of heterotopic ossification (HO) pathogenesis., Methods: Recent articles about HO including the risk factors and pathogenesis were reviewed and comprehensively analyzed., Results: The pathogenesis of HO is not completely understood, but the extracellular factors, signaling pathways, and transcription factors in the pathogenesis of HO are understood deeply, such as bone morphogenic protein, Smad signaling, and core binding factor alpha1/runt-related transcription factor 2, which are probably involved in HO. Furthermore, some related microRNAs are also probably involved in HO., Conclusion: The pathogenesis of HO should be further investigated so as to lay a foundation for preventing and treating HO.

Objective: To evaluate the security and effectiveness of nano-hydroxyapatite/polyamide 66 (n-HA/PA66) cage in reconstruction of spinal stability after resection of spinal tumor., Methods: Between January 2008 and December 2009, 11 patients with spinal tumor underwent surgical resection and strut graft with n-HA/PA66 cage. There were 6 males and 5 females with an average age of 44.5 years (range, 16-61 years). The average disease duration was 6.8 months (range, 2-14 months). The locations of lesions included cervical spine (2 cases), thoracic spine (6 cases), and lumbar spine (3 cases). Among them, there were 5 metastatic carcinomas, 2 giant cell tumors, 1 osteoblastoma osteosarcoma, 1 chondrosarcoma, and 2 non-Hodgkin lymphoma. According to Frankel criteria for nerve function classification, there were 1 case of grade A, 3 cases of grade B, 2 cases of grade C, 2 cases of grade D, and 3 cases of grade E., Results: Incisions healed by first intention in all patients, no operative or postoperative complication occurred. Four cases of metastatic carcinoma died of primary disease during 5-9 months after operation. Seven cases were followed up 14.4 months on average (range, 10-18 months). All patients gained significant improvement of the neurological function at 3 months after operation. All cases obtained bone fusion and good spinal stability without displacement and subsidence of the n-HA/PA66 cage. The intervertebral height of the adjacent segments was (110.5 +/- 16.1) mm at 3 months after operation and (109.4 +/- 16.2 ) mm at the final follow-up, showing significant differences when compared with the preoperative height [(97.5 +/- 15.4) mm, P < 0.05], but no significant difference between 3 months after operation and the final follow-up. In 2 patients undergoing surgery via anterior approach, bilateral pleural effusion on both sides occurred and were cured after closed thoracic drainage. During the follow-up, 2 cases (1 chondrosarcoma and 1 giant cell tumor) relapsed and underwent reoperations., Conclusion: n-HA/PA66 cage can provide satisfactory bone fusion and ideal spinal stability without increasing the risk of recurrence and complications during the surgical treatment of spinal tumors. It is an ideal selection for reconstruction of spinal stability.

Objective: To summarize the basic research and the clinical application of biodegradable interbody fusion Cage., Methods: Recent literature concerning biodegradable interbody fusion Cage at home and abroad was extensively reviewed, and current developments of the basic research and the clinical application of biodegradable interbody fusion Cage were investigated., Results: Basic research shows that the stiffness of biodegradable interbody fusion Cage is lower than that of metallic Cage, so it can enhance interbody fusion. As interbody fusion proceeded, biodegradable interbody fusion Cage degrades constantly, but the speed of degradation can not keep in parallel with that of fusion. In addition, the tissue response to degradation products is controversy. Clinical application shows that the biodegradable interbody fusion Cage can enhance interbody fusion and maintain disc space height. The short-term results are good, however, the long-term results need further observation., Conclusion: Biodegradable interbody fusion Cage can effectively enhance interbody fusion.

Objective: To review present situation and progress in clinically treating floating shoulder injury., Methods: Recent literature concerned treatment of floating shoulder injury was reviewed and analyzed in terms of anatomy, pathogenesis, diagnosis, and treatment., Results: Conservative treatment and operative treatment can get good outcome. But the value of the results was limited, because different evaluation criteria were used in the literature., Conclusion: There is no uniform standards about the treatment of the floating shoulder injury. Both conservative treatment and operative treatment have advantages and disadvantages, which method will be used to treat the floating shoulder injury based on local damage and the patient's general condition.

Objective: To evaluate pulmonary function changes in patients with severe scoliosis undergoing anterior release, posterior segmental fixation and fusion, and convex thoracoplasty by resecting a short length of rib., Methods: From January 2006 to July 2007, 16 patients with severe scoliosis were treated with anterior release, posterior segmental fixation and fusion, and convex thoracoplasty by resecting a short length of rib. There were 6 males and 10 females with an average age of 16.9 years (range, 10-24 years). There were 1 case of Lenke 1 curve, 9 cases of Lenke 2 curve, and 6 cases of Lenke 4 curve. The preoperative Cobb angle was (104.8 +/- 10.9) degrees and the preoperative thoracic kyphotic angle was (30.0 +/- 4.2) degrees. The preoperative height of "razor back" deformity was (5.9 +/- 1.2) cm. Before operation, the actual value of forced vital capacity (FVC) was (2.04 +/- 0.63) L and that of forced expiratory volume in 1 second (FEV1.0) was (1.72 +/- 0.62) L. The percentage of actual values to expected ones in FVC was 70% +/- 16%, and that in FEV1.0 was 67% +/- 15%. All patients had pulmonary function tests before operation and 3, 6, 12, 24 months after operation., Results: All wounds healed by first intention. The Cobb angle at 24-month follow-up was (53.4 +/- 18.6) degrees and the correction rate was 49.0% +/- 15.3%. The thoracic kyphotic angle at 24-month follow-up was (34.0 +/- 2.4) degrees and the correction rate was 13.3% +/- 2.2%. The height of "razor back" deformity at 24-month follow-up was (2.2 +/- 0.8) cm. Compared with preoperative level, all these data showed significant differences (P < 0.05). At 3 and 6 months, the actual values of FVC and FEV1.0 declined, but no significant difference was found (P > 0.05). At 12 and 24 months, the actual values of FVC and FEV1.0 were close to the preoperative level (P > 0.05). The percentages of actual values to expected ones in FVC and FEV1.0 indicate continued improvement in pulmonary function from the postoperative 3 to 24 months follow-up. Compared with preoperative level, the percentages of actual values in FVC declined 19% 3 months postoperatively (P < 0.05) and 12% 6 months postoperatively (P < 0.05). The percentages of actual values to expected ones in FEV1.0 declined 16% 3 months postoperatively (P < 0.05), and 10% 6 months postoperatively (P < 0.05). The percentages of actual values to expected ones in FVC and FEV1.0 were close to the preoperative level 12 and 24 months after operation (P > 0.05)., Conclusion: In severe scoliosis patients who are treated with anterior release, posterior segmental fixation and fusion, and convex thoracoplasty by resecting a short length of rib, pulmonary function decreases obviously 3-6 months after operation. And it returns to the operative baseline 12-24 months after operation.

Objective: To evaluate the effect of minimally invasive dynamic hip screws (MIDHS) in treating aged intertrochanteric fractures., Methods: From April 2006 to March 2008, 49 aged patients with intertrochanteric fractures were treated with MIDHS. There were 22 males and 27 females, aged 65-78 years (average 70.2 years). Fracture was caused by traffic accident in 7 cases, by falling from height in 3 cases, and by injury from fall in 39 cases. The time from injury to operation was 2-12 days (average 5.5 days). According to Evans classification, there were 28 cases of types I, II (stable fracture) and 21 cases of types III, IV (unstable fracture). If the Singh index 3 was defined as osteoporosis, the osteoporotic rate was 71.4% (35/49). All patients were on a radiolucent fracture traction table and their fractures had satisfactory closed reduction. After the guide wire was inserted and reamed under fluoroscopy, the lag screw and side plate were introduced through the small incision. In all unstable fractures, an additional, antirotational and large cancellous bone screw was used cranial to the DHS., Results: The average operation time was 65.2 minutes. The average blood loss was 189.3 mL. All patients had satisfactory reduction and 79.6% (39/49) had adequate lag screw positions. The average postoperative hospitalization days was 5.8 days (3-12 days). All incision healed at stage I. There was no postoperative complications. Forty-nine patients were followed up 12 to 30 months (average 19.8 months). Fractures healed within 16 weeks in 47 patients and the average healing time was 13.1 weeks (12-16 weeks). The average Harris scoring was 90.8 (75-95). Implant failure and nonunion occurred in 2 cases, no serious complication occurred in other patients., Conclusion: The MIDHS is a simple, safe and effective method for treatment of aged intertrochanteric fractures.

Objective: To analyze the spinal injury in Wenchuan earthquake and to investigate its clinical features., Methods: Data of 146 patients in Wenchuan earthquake with spinal injuries (79 males, 67 females; aged 11-88 years old, average 51 years old) were collected and analyzed epidemiologically. Two patients under 16 years of age, 15 patients with the fractures of spinous process, transverse process or vertebra lamina, 1 patient with spinal fractures of type A2 according to AO classification but no corresponding type in Denis classification, and 9 patients with upper cervical injuries were excluded. The remaining 119 patients were divided into two groups according to their age: group A in which 78 patients were under 60 years of age, including 40 males and 38 females aged 18-58 years old (average 41 years old), and group B in which 41 patients were 60 years of age or above, including 24 males and 17 females aged 60-88 years old (average 71 years old). Analyses for the two groups were compared., Results: The leading causes of spinal injuries were fall from high places (27.40%) and crush by heavy objects (67.81%). According to Denis classification, the major types of spinal injuries were burst fracture (54.62%) and compression fracture (33.61%). Serious nerve injury, defined as grade A, B and C in ASIA neurological function assessment, occurred in 31.51% of patients. The most common injured site was in thoracic or lumbar vertebrae (78.77%), and 52.74% of patients had combined injuries, among which the fractures of limb (30.14%) and rib (19.86%) were the most common. Multi-level spinal fractures happened to 22.60% of patients. Comparative analysis revealed the rate of injury caused by fall from high places in group A (34.62%) was much higher than that in group B (12.20%). The commonest type of fracture in group A was burst fracture (58.97%), and it was compression fracture in group B (48.78%). The rate of serious nerve injury in group B (24.39%) was much lower than that in group A (44.87%). The rate of combined injury and multilevel vertebral body injury in group B was 70.73% and 39.02%, respectively, which was much higher than that in group A (combined injury 43.59%; multilevel vertebral body injury 21.79%). There were significant differences between two groups in all the indicators derived from clinical data (P < 0.05)., Conclusion: In Wenchuan earthquake, the leading causes of spinal injuries are fall from high places and crush by heavy objects, the major types of fracture are compression fracture and burst fracture, and the occurrence rates of spinal injury, combined injury and multilevel vertebral body injury are high.

Objective: To investigate the possibility of repairing articular cartilage defects with the mesenchymal stem cells (MSCs)- seeded type I collagen-glycosaminoglycan(CG) matrices after being cultured with the chondrogenic differentiation medium., Methods: The adherent population of MSCs from bone marrow of 10 adult dogs were expanded in number to the 3rd passage. MSCs were seeded into the dehydrothermal treatment (DHT) cross-linked CG matrices; 2 x 10(6) cells per 9-mm diameter samples were taken. Chondrogenic differentiation was achieved by the induction media for 3 weeks. Cell contractility was evaluated by the measurement of the cell-mediated contraction of the CG matrices with time in culture. The in vitro formation of the cartilage was assessed by an assay employing immunohistochemical identification of type II collagen and by immunohistochemistry to demonstrate smooth muscle actin (SMA). The cells seedling CGs were implanted into cartilage defects of canine knee joints. Twelve weeks after surgery, the dogs were sacrificed and results were observed., Results: There was significant contraction of the MSCs-seeded DHT cross-linked CG scaffolds cultured in the cartilage induction medium. After 21 days, the MSC-seeded DHT cross-linked matrices were contracted to 64.4% +/- 0.3%; histologically, the pores were found to be compressed and the contraction coupled with the newly synthesized matrix, transforming the MSCs-seeded CG matrix into a solid tissue in most areas. The type II collagen staining was positive. The SMA staining was positive when these MSCs were seeded and the contracted CGs were implanted into the cartilage defects of the canine knee joints to repair the cartilage defects. The function of the knee joints recovered and the solid cartilaginous tissue filled the cartilage defects. Conclusion The results demonstrates that MSCs grown in the CG matrices can produce a solid cartilaginous tissue containing type II collagen after being cultured with the chondrogenic differentiation medium and implanted into cartilage defects. We hypothesize that the following steps can be performed in the chondrogenic process: (1)MSCs express SMA, resulting in matrix contraction, thus achieving a required cell density (allowing the cells to operate in a necessary society); (2)Cells interact to form a type II collagen-containing extracellular matrix (and cartilaginous tissue); (3)Other factors, such as an applied mechanical stress, may be required to form a mature cartilage with the normal architecture.

Objective: To explore the relationship of the limited resource of the autologous bone marrow mesenchymal stem cells (MSCs) in articular cavity to the treatment results of full-thickness articular cartilage defect, and to investigate whether the extrogenous sodium hyaluronate (SH) promotes the migration of MSCs cultured in vitro to the articular defect in vivo., Methods: Sixty-six Japan rabbits were made the model of the full-thickness articular cartilage defect (5 mm width and 4 mm depth). The autologous MSCs were extracted from the rabbit femur, cultured in vitro, labeled by Brdu, and injected into the injured articular cavity with or without SH. The experiment was divided into 4 groups; group A (MSCs and SH, n=15); group B (MSCs, n=15); group C (SH, n=18); and group D (non-treatment, n=18). The morphologic observation was made by HE staining, Mallory staining and immunohistochemical staining after 5 weeks, 8 weeks and 12 weeks of operation., Results: There were significant differences in the thickness of repairing tissue between group A and group B (P<0.01); but there were no significant differences between group A and group C, and between group B and group D (P>0.05). The histological observation showed that the main repairing tissue was fibrocartilage in group A and fiber tissue in group B., Conclusion: MSCs cultured in vitro and injected into the articular cavity can not improve the treatment results of the articular cartilage defect. Extrogenous SH has effect on repairing cartilage defect. The extrogenous SH has no effect on the chemotaxis of the MSCs, and on the collection of MSCs into the joint defect.