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Objective: To evaluate the mid-term effectiveness of nano-hydroxyapatite/polyamide66 (n-HA/PA66) cage in the anterior spinal reconstruction., Methods: There were 177 patients who undergone the anterior decompression and fusion with n-HA/PA66 cage and internal fixation between January 2008 and January 2010 included in this study. There were 117 male and 60 female patients aged from 18 to 74 years. The diagnoses included cervical fracture in 47 patients, thoracic or lumbar fracture in 50 patients, cervical spondylopathy in 58 patients, spinal tuberculosis in 17 patients and spinal tumor in 5 patients. The X-ray and three-dimensional CT were followed up in all these patients to observe the spinal alignment, the rate of fusion and the rate of n-HA/PA66 cage subsidence and translocation. The neurological functions of patients with spinal fracture were evaluated by Frankel grading; the improvement of the clinical symptoms of the other patients were assessed by visual analogue scale (VAS) scores and Japan Orthopaedic Association (JOA) scores or SF-36 scores., Results: All the 177 patients had been followed-up for 36 to 70 months after surgery (average 51 months). Except the slight cage translocation been found in the only one patient with cervical fracture, no cage prolapsed or breakage was exist in our patients up to the last follow-up. In the patients with spinal fracture, the mean time for fusion was 4.5 months, the rate of fusion was 95.9% and the rate of cage subsidence was 5.2%; while in the patients with cervical spondylopathy, the mean time for fusion was 4.4 months, the fusion rate was 96.5% and the subsidence rate was 5.2%; while in patients with spinal tuberculosis, the mean fusion time was 5.5 months, the rate of fusion was 94.0%, the rate of subsidence was 5.9%; and in the patients with tumor, the mean time for fusion was 6.0 months, the fusion rate was 100%, and the cage subsidence was found in only one patient. The preoperative symptoms of each patient were improved to varying degrees after surgery. At the last follow-up, the Frankel grading of patients of spinal fracture with incomplete paralysis improved 0 to 2 classes; the VAS, JOA or SF-36 scores of the other patients were improved significantly than their respective scores before surgery (t = 2.982, 4.126 and 3.980, P < 0.05)., Conclusions: The n-HA/PA66 cage has much higher rate of osseous fusion and lower cage subsidence, it is an ideal cage which can provide effective restoring and maintaining for the spinal alignment and intervertebral height. Moreover, the mid-term clinical results of anterior reconstruction with this cage in the patients with spinal trauma, degeneration, tuberculosis or tumor are well content.

This retrospective study analyzed 276 cases of giant cell tumour of bone in the appendicular skeleton of patients first diagnosed and treated at the Orthopaedic Department of the West China Hospital in Sichuan University between 1988 and 2007. Fifty-eight percent of the tumours involved the knee region. The most common primary treatment was curettage (162 patients) combined with adjuvant local therapy. The effects of bone cement (PMMA), high-speed burring, electro- cauterization, liquid nitrogen, and phenol on the recurrence rate were also analyzed. The differences in local recurrence rates were analyzed between giant-cell tumours confined to bone (Campanacci grades I and II) and giant-cell tumours with extraosseous extension (Campanacci grade III) treated with intralesional curettage. The recurrence rate of patients who received the first treatment at our institution was 11.2%. Recurrence was observed in 31 cases and multiple recurrences were observed in 5 cases. Treatment included intralesional curettage (173%), marginal excision (143%), wide excision (1.9%), or radical resection (0%). Metastases, which mainly involved the lung, occurred in 6 cases (2.2%). There was a significantly lower recurrence rate (p = 0.004) following intralesional curettage combined with high-speed burring (n = 102) as compared with intralesional curettage without high-speed burring (n = 60). Although the efficacy of liquid nitrogen and electrocauterization did not reach significance, they seem to have a similar effect to high-speed burring. Therefore, we recommend high-speed burring as a necessary adjuvant therapy. The combination of all adjuvants (burring, liquid nitrogen, and electro-cauterization) is recommended as a standard treatment. Cement filling of the cavity after curettage was not widely used in this series, but its merits have been reported in several studies; we therefore recommend that cement filling should be added to the adjuvants to be used after burring, liquid nitrogen and/or electrocauterization.

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 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 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.

Background: The surgical technique of hemivertebrae excision varies from anteroposterior procedures to posterior-alone resections according to the experience and preference of surgeons. Both the approaches are reliable and give relatively good results. This study aims to evaluate and compare the clinical and radiological results of these two approaches for hemivertebrae resection., Materials and Methods: Sixty patients were retrospectively enrolled between 2006 and 2009. The subjects included 32 women and 28 men, with a mean age of 12.9 years (range: 5-24 years). Thirty patients who underwent one-stage anteroposterior hemivertebrae resection (the AP group) were followed for 38.5 months, and the other 30 patients who underwent posterior resection (the P group) were followed for 20.6 months. Clinical and radiological assessments were performed preoperatively, 1 week postoperatively, and at the final follow-up. The operation time, blood loss, degree of correction of the main curve/segmental curve/kyphosis, the average hospital stay, and complications were reviewed and compared between the two groups., Results: The mean operation time, blood loss, and hospital stay of the AP group and the P group were 451 min vs 248.5 min, 1290 ml vs 910 ml, and 21.93 days vs 18.97 days, respectively (P<.05). The average correction rate of the main curve/segmental curve/kyphosis of the AP group and the P group was 68.5% vs 66.2%, 71.5% vs 69.6%, and 57.4% vs 56.1%, respectively (P>.05). Overall complication rate was 6.7% in the AP group vs 10% in the P group (P>.05)., Conclusion: Posterior hemivertebrael resection is a promising approach for congenital scoliosis in terms of relative safety, degree of correction achieved, reduced operative time and blood loss.

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.

This paper is aimed to investigate the feasibility of applying the small intestine submucosa (SIS) as the scaffold in constructing tissue engineering cartilage in vitro. We obtained SIS from the small intestine of specific pathogen-free pigs. Then we isolated tunica submucosa layer from the mucosal, muscular, and serosal layers by gentle mechanic abrasion. The SIS was made acellular by combination of detergent and enzyme digestion. The chondrocytes were seeded onto the SIS and were cultured for 3 weeks. The cell growth, attachment and distribution were detected by histochemical stain, immunohistochemical stain and scan electron microscope. The chondrocytes could adhere and grow well on the matrix surface, and synthesize a large of the GAG and type U collagen. However, the chondrocytes grew only on the surface andsuperficial layer of the scaffold, they did not move into the inner part of the scaffold. It could be concluded that SIS has good cellular compatibility without cytotoxicity and provides temporary substrate to which these anchorage-dependent cells can adhere, and stimulate the chondrocytes anchored on the scaffold to proliferate and keep differentiated phenotype. Further study will be needed to promote the ability of chondrocyte chemotaxis in order to distribute the chondrocytes into the whole scaffold uniformly.

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.