Case series: O-arm navigation assisted by the Wiltse approach improves the accuracy of pedicle screw placement in ankylosing spondylitis combined with thoracolumbar fractures.

Here we assessed the accuracy of O-arm navigation assisted by Wiltse approach to improve based pedicle screw insertion in ankylosing spondylitis combined with thoracolumbar fractures. We then compared it with the freehand pedicle screw insertion technique. The study sample included 32 patients with ankylosing spondylitis combined with thoracolumbar fractures. Pedicle screw reduction and internal fixation was performed under an O-arm navigation system assisted by a Wiltse approach-combined osteotomy ("navigation group," n = 17) and posterior pedicle screw reduction and internal fixation was performed using freehand technique combined osteotomy ("freehand group," n = 15). We then compared the operation time and bleeding volume between the 2 groups. The visual analog scale (VAS) and Oswestry disability index (ODI) were then used to evaluate the clinical efficacy and the kyphosis Cobb angle was used to evaluate the radiological efficacy before operation, 3 days after operation and after the last follow-up. All complications were noted when detected. Finally, classification of screw positions as proposed by Neo et al was used to evaluate the relationship of the position between the screw, the bone cortex, and the incidence of screw penetration. All patients were followed up for 18 to 36 months (i.e., 24.2 ±â€…3.5 months). The operation time and intraoperative bleeding volume of the navigation group were significantly shorter (lower) than those of the freehand group (P < .05). In addition, Both groups showed significantly decreased VAS, ODI, and Cobb angle 3 days after the operation and at the last follow-up when compared to values recorded pre-operation. However, we found no significant difference in VAS, ODI, and Cobb angle between the 2 groups (P > .05). We identified no complications (e.g., infection, VTE/PE, or nerve injury). Moreover, the pedicle screw placement position of the navigation group was better than that of the freehand group (P < .05), and the screw cortical penetration rate was lower than the freehand group (P < .05). During the process of posterior pedicle screw placement, O-arm navigation assisted by the Wiltse approach can significantly reduce operation time, minimize the amount of bleeding volume, and enhance the accuracy of pedicle screw implantation.

[Current understanding of intervertebral space height in anterior cervical fusion].

Anterior cervical fusion surgery is the first choice for spine surgeons in the treatment of cervical spine diseases. It has significant effects in treating cervical degenerative diseases, trauma and tumors and other cervical diseases. In anterior cervical fusion, it is necessary to use a distractor to properly distract the intervertebral space, so as to fully expose and relieve the compressive factors, restore the physiological height, curvature and stability of the lesion segment, and achieve the best surgical effect. However, there is currently no consensus on the standard distraction height for the intervertebral space during anterior cervical surgery. This article reviewsed the progress of intervertebral space height in anterior cervical fusion from three dimensions:the relationship between intervertebral space height and cervical disc degeneration mechanism, the selection of intervertebral space height during operation, the recovery of intervertebral space height and the postoperative effect, so as to provide theoretical basis and reference for spinal surgeons when performing intervertebral distraction during operation.

Is preemptive analgesia a good choice for postoperative pain relief in lumbar spine surgeries?: A meta-analysis of randomized controlled trials.

BACKGROUND: Lumbar spine surgery is associated with moderate-to-severe postoperative pain. Adequate pain management during the postoperative period facilitates rehabilitation. Recently, preemptive analgesia has been considered among the important analgesic methods for reducing postoperative pain. However, its efficacy in postoperative pain relief after lumbar spine surgery remains unclear. This study aimed to evaluate the effects of preemptive analgesia on lumbar spine surgery. METHODS: We searched for randomized controlled trials in PubMed (1996 to May 2020), Embase (1980 to May 2020), and Cochrane Library (CENTRAL, May 2020). We included seven studies that evaluated the preemptive analgesic efficacy in lumbar spine surgeries. RESULTS: Seven studies, including 509 patients, met the inclusion criteria. Pooled data revealed that preemptive analgesia is effective for lumbar spine surgeries with respect to the visual analog scale score (P < .05), total morphine equivalent consumption (P < .05), and length of stay (P < .05), without increasing complications (P = .73). CONCLUSIONS: Our findings indicate that preemptive analgesia is safe and effective for lumbar spine surgery.

Is the proximal adductor canal block a better choice than the distal adductor canal block for primary total knee arthroplasty?: A meta-analysis of randomized controlled trials.

BACKGROUND: Total knee arthroplasty is accompanied by moderate to severe postoperative pain. Postoperative pain hampers the functional recovery and lowers patient satisfaction with the surgery. Recently, the adductor canal block (ACB) has been widely used in total knee arthroplasty. However, there is no definite answer as to the location of a continuous block within the ACBs. METHOD: Randomized controlled trials about relevant studies were searched in PubMed (1996 to Oct 2019), Embase (1996 to Oct 2019), and Cochrane Library (CENTRAL, Oct 2019). RESULTS: Five studies involving 348 patients met the inclusion criteria. Pooled data indicated that the proximal ACB was as effective as the distal ACB in terms of total opioid consumption (P = .54), average visual analog scale (VAS) score (P = .35), worst VAS score (P = .19), block success rate (P = .86), and time of catheter insertion (P = .54). CONCLUSIONS: Compared with the distal ACB, the proximal ACB showed similar analgesic efficacy for total opioid consumption, average VAS score, worst VAS score, block success rate, and time of catheter insertion. However, because of the limited number of involved studies, more high-quality studies are needed to further identify the optimal location of the ACB.

[Comparison of clinical effects of two anterior cervical decompression with fusion on treating two segment cervical spondylotic myelopathy].

OBJECTIVE: To explore the clinical effects of anterior cervical discectomy with fusion (ACDF) and anterior cervical corpectomy with fusion (ACCF) in treating adjacent two-segment cervical spondylotic myelopathy (CSM). METHODS: The clinical data of 37 patients with adjacent two segment CSM treated from January 2016 to December 2017 were retrospectively analyzed, including 15 males and 22 females, aged from 43 to 69 years old with an average of 54.6 years. The patients were divided into ACDF group (group A, n=17) and ACCF group (group B, n=20) according to the different surgery. The operation time and intraoperative blood loss were recorded;the Cobb angle and cervical curvature in the cervical fusion segments before surgery and 1, 12 months after surgery were observed;Japanese Orthopaedic Association (JOA) score was used to evaluate the surgical efficacy, and the postoperative complications were analyzed. RESULTS: All patients were followed up for 12 to 24 months with an average of 18.5 months. Operation time and intraoperative blood loss in group A were (106.3±22.6) min, (52.2±26.4) ml, respectively, while were (115.6±16.8) min, ( 61.7±20.7) ml in group B. There was no statistically significant in operation time between two groups(P>0.05);intraoperative blood loss in group B was larger than group A(P<0.05). The preoperative and postoperative 1 and 12 months, cervical curvature and Cobb angle of cervical fusion segment in group A were (11.28±1.40)°, (17.56±1.90)°, (16.64±1.80)° and (4.93±4.20) °, (9.44±2.60)°, (9.25±2.80)°, respectively, and in group B were (10.59± 1.20)°, (16.26±2.10)°, (15.76±2.50)° and (4.75±3.90)°, (7.98±2.10)°, (7.79±3.00)°. The cervical curvature and Cobb angle in all cervical fusion segments at 1, 12 months after surgery were obviously improved, and group A recovered more significantly than group B (P<0.05). The JOA scores in group A were 9.46±1.70, 11.56±1.40, 14.86±1.20 before operation and 1 and 12 months after operation, and group B were 9.11±1.50, 11.40±1.30, 15.12±1.60, respectively. The postoperative JOA scores of the two groups were significantly improved (P<0.05), and there was no statistically significant difference between two groups at the same time (P>0.05). At the final follow up, in group A, dysphagia occurred in 2 cases, cage displacement in 1 case, and no titanium plate screw loose was found;and in group B, dysphagia occurred in 4 cases, titanium mesh collapse in 2 cases, titanium plate screw loose in 1 case. CONCLUSION: Two types of anterior cervical decompression and fusion for the treatment of two segment cervical spondylotic myelopathy can effectively decompress and improve the Cobb angle and cervical curvature of the affected vertebra. The ACDF surgical procedure can directly removethe compressive thing at intervertebral level, which will lead to little vertebral body damage and favorably recovered cervical curvature. The ACCF surgical procedure has a large operation space, which can easily remove the posterior vertebral osteophyte and the calcified posterior longitudinal ligament. Long-term follow-up shows that ACDF and ACCF have good surgical procedures, mature technology, and close efficacy.

[Treatment of degenerative scoliosis with oblique lateral lumbar interbody fusion combined with long-segment internal fixation through navigation for posterior].

OBJECTIVE: To assess the early clinical effects of oblique lateral lumbar interbody fusion (OLIF) combined with posterior long-segment internal fixation through O-arm CT navigation for the treatment of degenerative scoliosis. METHODS: The clinical data of 15 patients with degenerative scoliosis treated by OLIF combined with posterior long-segment internal fixation through O-arm CT navigation between April 2016 and December were retropectively analyzed. There were 3 males and 12 females, aged from 55 to 73 years old with an average of (62.2±5.3) years. The operation time, intraoperation blood loss, the rate of excellentand good of pedicle screw placement, and complications were recorded. Before surgery, 1 week after surgery and at the final follow-up, the visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the patients' clinical symptoms;standing X-ray film, lumbar spine CT examination was performed at 6 months after surgery to observe coronal scoliosis Cobb angle, lumbar lordosis (LL), intervertebral space height, sagittal vertical axis (SVA), intervertebral fusion, etc. RESULTS: The mean operation time and intraoperative blood loss were respectively (98.7±16.8) min and (50.2±10.7) ml in OLIF surgery, while were (101.5±23.4) min and (63.1±19.7) ml in the surgery of posterior long segment internal fixation. The total mean operation time and intraoperative blood loss were (200.2±40.2) min and (113.3±30.4) ml. All patients were followed from 12 to 25 months with an average of (16.5±5.3) months. Low back pain VAS, lower limb pain VAS and ODI reduced from preoperative (6.8±1.6), (6.2±1.1) scores and (64.6±10.4)% to (1.4±1.0), (1.0±0.5) scores, and (15.8±4.5)% at the final follow-up, the differences were statistically significant(P<0.05). Coronal scoliosis Cobb angle and SVA decreased from preoperative (20.3±13.5)°, (42.3±16.5) mm to (5.5±3.1)°, (25.1±10.9) mm at the final follow-up, and the differences were statistically significant (P<0.05). LL and intervertebral space height increased from preoperative (25.8±8.2)°, (5.9±2.7) mm to (39.3±9.1)°, (10.9±1.2) at the final follow-up, and the differences were statistically significant(P<0.05). Total 240 nails were placed through O-arm CT navigation with the rate of excellent and good of 96%(230/240). Six months after operation, CT of lumbar spine showed interbody fusion of bone. One patient developed anterior medial pain in the left thigh, and two patients experienced transient lefthip flexion after surgery, both of whom recovered during subsequent follow-up. CONCLUSION: The early clinical effect of oblique lateral lumbar interbody fusion combined with posterior long segment internal fixation through O-arm CT navigation is satisfactory in treatment of degenerative scoliosis. It has the advantages of minimal invasion, accurate navigation of nail placement, high bone fusion rate and few complications. It can provide new options for minimally invasive treatment of degenerative scoliosis.

[Choice of osteotomy methods for old thoracolumbar osteoporotic fracture with kyphosis].

OBJECTIVE: To investigate the clinical outcome of single or double-segment pedicle subtraction osteotomy (PSO) for the treatment of old thoracolumbar osteoporotic compression fractures with kyphosis. METHODS: The clinical data of 26 patients with old thoracolumbar osteoporotic compression fractures with kyphosis who underwent surgery from January 2015 to June 2017 were retrospectively analyzed. There were 12 males and 14 females, aged from 58 to 72 years old with an average of 65.6 years. The time interval from fracture to surgery was (8.2±1.5) years. According to different surgical methods, the patients were divided into single-segment PSO group (group A) and double-segment PSO group(groupB). The perioperative data, preoperative and postoperative imaging data and postoperative complications were recorded, and the Oswestry Disability Index (ODI) and visual analogue scale (VAS) were used before and after surgery to evaluate the clinical effect. RESULTS: All patients were followed up for 6-24 months with an average of 14.5 months. There was a statistically significant difference in operation time and intraoperative blood loss between the two groups (P<0.05). There was no significant difference in total drainage volume and length of hospital stay (P>0.05). The postoperative correction angle of the single segment PSO group was (33.3± 9.4) ° with the correction rate of 85.3% and the double segment PSO group was (41.0±13.5) ° with the correction rate of 92.7%, and there was statistical significance between two groups (P<0.05). There were no significant differences in postoperative lumbar lordosis (LL), sagittal vertical axis (SVA), and ODI, VAS between two groups (P>0.05). One case of cone injury occurred in the single-segment PSO group and recovered after treatment. There were no complications of spinal cord injury in the double segment group. Loose screws occurred during surgery in three patients in the single-segment PSO group and one patient in the double-segment PSO group (P<0.05). All 4 patients were re inserted with screws after using bone cement to reinforce the nail pathway. There were no complications such as anterior spinal vascular and nerve damage or osteotomy unfusion. CONCLUSION: Both single-segment PSO and double-segment PSO can achieve good orthopedic and clinical effects in the treatment of old thoracolumbar osteoporotic fractures with kyphosis. For patients with correction angles greater than 40° , the double-segment PSO provides a better correction angle and is safer, but it is with longer operation time and more intraoperative bleeding.

[Progress on prevention and treatment of heterotopic ossification].

Heterotopic ossification is the formation of pathological bone in non-skeletal tissues (including muscles, tendons or other soft tissues), and the pathogenesis is not completely clear. It is often caused by musculoskeletal trauma, postoperative bone and joint surgery, or damage of the nervous system, the clinical manifestations are joint swelling, pain, and movement disorders, which often occur around the hips, knees, and elbows. At present, the prevention of heterotopic ossification mainly includes drugs, radiotherapy, molecular biological mechanism intervention, and Chinese medicine-related measures. Among them, drugs and radiotherapy are more effective methods to prevent heterotopic ossification. The intervention of molecular biology mechanism to prevent heterotopic ossification has become a new research direction and focus of attention inrecent years, and is basically at the experimental research stage. The treatment of heterotopic ossification includes various methods such as drugs, physical therapy, and surgery. Among them, surgery is recognized as the most effective treatment, however there are still some controversies and disagreements about the choice of operation time and surgical methods.

[Application of ultrasonic bone knife in osteotomy of degenerative kyphosis].

OBJECTIVE: To explore the safety and effectivity of ultrasonic bone knife in osteotomy of degenerative kyphosis. METHODS: The clinical data of 32 patients with degenerative kyphosis treated from February 2014 to May 2016 were retrospectively analyzed. There were 12 males and 20 females, aged 50 to 71 years with an average of (62.1±12.3) years. Preoperative Cobb angle was 25.3° to 36.7° with an average of (28.6±10.2) °. All patients underwent multi-segment Ponte osteotomy combined with posterior long segmental internal fixation. According to different osteotomy tools, the patients were divided into traditional tool group (group A, 18 cases) and ultrasonic bone knife group (group B, 14 cases). The operation time, laminectomy time, number of osteotomy segments, intraoperative blood loss, postoperative drainage, hospitalization time and postoperative complications were recorded.Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate clinical outcomes before and 1 month after surgery. RESULTS: All the patients were followed up from 8 to 24 months with an average of 16.4 months. There were no significant differences in operative time and hospitalization time between two groups (P>0.05). Intraoperative single laminectomy time of group A was more than that of group B (P<0.05). The number of osteotomy segments in group A was less than that in group B (P<0.05). Intraoperative blood loss and postoperative drainage in group A were more than that in group B (P<0.05). There were no significant differences in VAS and ODI between two groups (P>0.05). There were no dural, nerve and spinal cord injuries in both groups, and there were no complications such as improper operation of the instrument and nonunion of the osteotomy. CONCLUSION: The use of ultrasonic bone knife for Ponte osteotomy is safe and effective. It can effectively save the time of single laminectomy while reducing the amount of intraoperative blood loss and postoperative drainage. The safety and clinical efficacy of ultrasonic bone knife are no less than traditional tools.

Controlled study on Gamma nail and proximal femoral locking plate for unstable intertrochanteric femoral fractures with broken lateral wall.

The gamma nail and proximal femoral locking plate (PFLP) are both used for fractures. A controlled study was performed to determine the optimal implant. To assess and analyze the clinical effects of gamma nails and PFLPs for patients with unstable intertrochanteric femoral fractures, specifically with broken lateral walls. Thirty-six patients with unstable intertrochanteric femoral fractures and broken lateral walls were treated with gamma nails or PFLPs and retrospectively studied. The clinical data were compared. Duration of surgery and early full weight-bearing time were significantly longer in the PFLP group compared to the gamma nail group (P < 0.05). However, intraoperative fluoroscopy frequency and total blood loss in the PFLP group were significantly less than those in the gamma nail group (P < 0.05). No significant differences were found in hospitalized days, Parker Palmer mobility scores, Harris hip scores, and complications between the two groups. No difference in hip-functional recovery was found between the gamma nail group and the PFLP group, indicating that both the gamma nail and PFLP were effective for unstable intertrochanteric femoral fractures with a broken lateral wall. However, early weight bearing on the fractures was not encouraged in patients treated with PFLP.

Effects of a bone graft substitute consisting of porous gradient HA/ZrO2 and gelatin/chitosan slow-release hydrogel containing BMP-2 and BMSCs on lumbar vertebral defect repair in rhesus monkey.

Dense biomaterial plays an important role in bone replacement. However, it fails to induce bone cell migration into graft material. In the present study, a novel bone graft substitute (BGS) consisting of porous gradient hydroxyapatite/zirconia composite (PGHC) and gelatin/chitosan slow-release hydrogel containing bone morphogenetic protein 2 and bone mesenchymal stem cells was designed and prepared to repair lumbar vertebral defects. The morphological characteristics of the BGS evaluated by a scanning electron microscope showed that it had a three-dimensional network structure with uniformly distributed chitosan microspheres on the surfaces of the graft material and the interior of the pores. Then, BGS (Group A), PGHC (Group B), or autologous bone (Group C) was implanted into lumbar vertebral body defects in a total of 24 healthy rhesus monkeys. After 8 and 16 weeks, anteroposterior and lateral radiographs of the lumbar spine, microcomputed tomography, histomorphometry, biomechanical testing, and biochemical testing for bone matrix markers, including Type I collagen, osteocalcin, osteopontin, basic fibroblast growth factor, alkaline phosphatase, and vascular endothelial growth factor, were performed to examine the reparative efficacy of the BGS and PGHC. The BGS displayed excellent ability to repair the lumbar vertebral defect in rhesus monkeys. Radiography, microcomputed tomography scanning, and histomorphological characterization showed that the newly formed bone volume in the interior of the pores in the BGS was significantly higher than in the PGHC. The results of biomechanical testing indicated that the vertebral body compression strength of the PGHC implant was lower than the other implants. Reverse-transcription polymerase chain reaction and western blot analyses showed that the expression of bone-related proteins in the BGS implant was significantly higher than in the PGHC implant. The BGS displayed reparative effects similar to autologous bone. Therefore, BGS use in vertebral bone defect repair appears promising.

TRIB3 inhibits proliferation and promotes osteogenesis in hBMSCs by regulating the ERK1/2 signaling pathway.

Osteogenic differentiation in human bone marrow-derived mesenchymal stem cells (hBMSCs) is regulated by various factors, including bone morphogenetic proteins (BMPs), Notch, growth hormones and mitogen-activated protein kinases (MAPKs). Tribbles homolog 3 (TRIB3), a pseudokinase, plays an important role in cancer cells and adipocytes. However, TRIB3 function in osteogenic differentiation is unknown, although it is involved in regulating signaling pathways associated with osteogenic differentiation. Here, we found that TRIB3 was highly expressed during osteogenic differentiation in hBMSCs. Inhibition of focal adhesion kinase (FAK) or phosphatidylinositol 3-kinase (PI3K) resulted in a significant decrease in TRIB3 expression, and expression of TRIB3 was restored by increasing insulin-like growth factor-1 (IGF-1) via activating phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling. TRIB3 knock-down enhanced proliferation and decreased osteogenic differentiation at the middle stage of differentiation, and these effects were reversed by inhibiting the activation of extracellular signal-regulated kinase (ERK)-1/2. In conclusion, TRIB3 plays an important role in proliferation and osteogenic differentiation by regulating ERK1/2 activity at the middle stage of differentiation, and expression of TRIB3 is regulated by FAK in a PI3K/AKT-dependent manner.

Local influence of high molecular polyethylene particles on heterotopic ossification.

We studied the effect of molecular polyethylene particles on local heterotopic ossification. A total of 36 healthy Sprague-Dawley rats were randomly divided into the control group (n=18) and the observation group (n=18). High molecular polyethylene particles were injected to rupture Achilles tendon position in the observation group, and normal saline was injected in the control group. X-ray examinations were conducted on Achilles tendon in the 4th, 8th and 12th week after operation. The incidence rate of heterotopic ossification was evaluated, and bone trabecula morphological structure was studied under optical microscope after hematoxylin and eosin staining. Bone morphogenetic protein 2 (BMP-2), transforming growth factor-ß (TGF-ß), interleukin-1 (IL-1), tumor necrosis factor-α (TNF-α), runt-related transcription factor 2 (Runx2) and matrix metalloproteinase-9 (MMP-9) expression levels were also measured. Our results showed that heterotopic ossification incidence in the observation group was significantly lower than that in the control group. Achilles tendon structure in the control group increased in volume, and its texture was harder and cartilage-like. In the observation group, trabecular bone volume, thickness and quantity were more than those observed in the control group. BMP-2, TGF-ß, IL-1, TNF-α, Runx2 and MMP-9 levels in the observation group were significantly lower than those in the control group. We concluded that, high molecular polyethylene particles had a significant inhibiting effect on local heterotopic ossification.

[The metabolic profilings study of serum and spinal cord from acute spinal cord injury rats ¹H NMR spectroscopy].

OBJECTIVE: To establish the rat model of acute spinal cord injury, followed by aprimary study on this model with ¹H NMR based on metabonomics and to explore the metabonomics and biomarkers of spinal cord injury rat. METHODS: Twenty eight-week-old adult male SD rats of clean grade, with body weight of (200±10) g, were divided into sham operation group and model group in accordance with the law of random numbers, and every group had 10 rats. The rats of sham operation group were operated without damaging the spinal cord, and rats of model group were made an animal model of spinal cord incomplete injury according to the modified Allen's method. According to BBB score to observate the motor function of rats on the 1th, 5th, and 7th days after surgery. Postoperative spinal cord tissue was collected in order to pathologic observation at the 7th day, and the metabolic profilings of serum and spinal cord from spinal cord injury rats were studied by ¹H NMR spectroscopy. RESULTS: The hindlimb motion of rats did not obviously change in sham operation group, there was no significant difference at each time point;and rats of model group occurred flaccid paralysis of both lower extremities, there was a significant difference at each time; there was significant differences between two groups at each time. Pathological results showed the spinal cord structure was normal with uniform innervation in shame group, while in model group, the spinal cord structure was mussy, and the neurons were decreased, with inflammatory cells and necrotic tissue. Analysis of metabonomics showed that concentration of very low density fat protein (VLDL), low density fat protein (LDL), glutamine, citric acid, dimethylglycine (DMG) in the serum and glutathione, 3-OH-butyrate, N-Acetyl-L-aspartic acid (NAA), glycerophosphocholine (GPC), glutamic acid, and ascorbate in spinal cord had significant changes(P<0.05). CONCLUSIONS: There are significant differences in metabolic profile from serum and spinal cord sample between model group and sham operation group, it conduces to explain the changes of small molecular substances in serum and spinal cord tissue after spinal cord injury, this provides the research basis for targeted research on the role of metabolic markers in patients with acute spinal cord injury.

Evaluation of porous gradient hydroxyapatite/zirconia composites for repair of lumbar vertebra defect in dogs.

OBJECTIVE: To evaluate the effects of porous gradient composites with hydroxyapatite/zirconia and autologous iliac in repair of lumbar vertebra body defects in dogs. METHODS: (1) New porous gradient hydroxyapatite/zirconia composites were prepared using foam immersion, gradient compound and high temperature sintering; (2) A total of 18 adult beagle dogs, aged five to eight months and weighted 10-13 kg, were randomly assigned into two subgroups, which were implanted with new porous gradient hydroxyapatite/zirconia composites (subgroup A in 12) or autologous iliac bone (subgroup B in 6); (3) The post-operative data were analyzed and compared between the subgroups to repair the vertebral body defect by roentgenoscopy, morphology and biomechanics. RESULTS: The porosity of new porous gradient hydroxyapatite/zirconia composites is at 25 poles per inch, and the size of pores is at between 150 and 300 µm. The post-operative roentgenoscopy displayed that new-bone formation is increased gradually, and the interface between composites and host-bone becomes became blur, and the new-bone around the composites were integrated into host-bone at 24 weeks postoperatively in subgroup A. As to subgroup B, the resorption and restructure were found at six weeks after the surgery, and the graft-bone and host-bone have been integrated completely without obvious boundary at 24 weeks postoperatively. Histomorphologic study showed that the amount of bone within pores of the porous gradient hydroxyapatite/zirconia composites increased continuously with a prolonged implantation time, and that partial composites were degradated and replaced by new-bone trabeculae. There was no significant difference between subgroups (P > 0.05) in the ultimate compressive strengths. CONCLUSION: New porous gradient hydroxyapatite/zirconia composites can promote the repair of bony defect, and induce bone tissue to ingrow into the pores, which may be applied widely to the treatment of bony defect in the future.

[Effect of elongated-needle penetration intervention on spinal apoptosis and cell signal transduction in acute spinal cord injury rabbits].

OBJECTIVE: To observe the effect of elongated-needle penetration (ENP) stimulation of "Zhibian" (BL 54), "Shuidao" (ST 28), "Qihai" (CV 6) and "Zhongji" (CV 3) on spinal nerve cell apoptosis and cellular signal transduction in spinal cord injury rabbits, so as to reveal its mechanism underlying improvement of spinal injury. METHODS: A total of 80 adult Newzealand rabbits were randomized to control, model, ENP, ENP + LY 294002 (PI3K antagonist), ENP + PD 98059 (MEK antagonist) groups, with 16 rabbits in each group. The spinal cord injury model was established by using modified Allen's method (Gravity-drop device). Elongated-needle penetration was applied to bilateral BL 54, ST 28, CV 3 and CV 6, once daily for 3 times. For rabbits of the ENP+ LY 294002 and ENP+ PD 98059 groups, LY 294002 (10 microg, 20 microL), PD 98059 (3 microg, 20 microL) were separately given by intrathecal injection. Pathomorphological changes of the injured spinal cord (T13-L1) were observed after H.E. stain. Spinal cell apoptosis was detected by TUNEL,and phosphorylated (p)-Akt and p-ERK1/2 immunoactivity was detected by immunohistochemistry, and the expression levels of p-Akt, p-ERK1/2, cytochrome C (Cyt C) and Caspase-3 proteins were determined by Western blot (WB), and serum TNF-alpha content was assayed by ELISA. RESULTS: H. E. staining showed apparent structural changes as hemmorrhage, inflammatory cell infiltration, cellular edema and necrosis, and formation of vacuolation in the spinal cord in the model group, which was marked milder in the ENP group. TUNEL assay showed that the rate of apoptotic cells was notably increased in the model group than in the control group (P < 0.05), obviously decreased in the ENP group when compared with the model group (P < 0.05). Immunohistochemistry, WB and ELISA results showed that compared with the control group, spinal p-Akt and p-ERK1/2 protein expression levels in the model group were significantly decreased (P < 0.05), and Cyt C and Caspase-3 expression levels and serum TNF-a content were significantly increased in the model group (P < 0.05). Compared with the model group, the expression levels of p-Akt, p-ERK1/2 were significantly increased in the ENP group (P < 0.05), while Cyt C and Caspase-3 expression levels and TNF-alpha content were significantly down-regulated in the ENP group (P < 0.05). After intrathecal injection of PI3K and MEK antagonists, the effects of ENP were significantly weakened in reducing apoptosis rate, upregulating p-Akt and p-ERK1/2 expression and in down-regulating Cyt C and Caspase-3 expression and TNF-alpha content (P < 0.05), suggesting important roles of ERK1/2 mediated extracellular and PI3K/Akt mediated intracellular apoptotic signal transduction pathways in ENP induced repair of the traumatic tissues. CONCLUSION: ENP stimulation can decrease spinal injury and cell apoptosis in spinal injury rabbits, which may be closely related to its effects in up-regulating p-Akt and p-ERK1/2 and down-regulating Cyt C and Caspase-3 expression levels in the spinal cord and serum TNF-alpha content.

[Awn needle therapy on the impact of urinary retention after spinal cord injury].

OBJECTIVE: To investigate the therapeutic mechanism of point 8L54-through-point ST2S acupuncture with elongate needles in treating urinary retention after spinal cord injury. METHODS: Thirty-five healthy Japanese rabbits (weight 2.5 +/- 0.25 kg, 3 months old, male or female), used as experimental subjects, were divided into 4 groups involving blank group, model group, acupuncture group, elongate needles group (5 rabbits in blank group, 10 rabbits in each of the other group 10). Modified Allen's method was used to cause spinal cord injury model for the model group, the acupuncture group and the elongate needles group, the blank group was only sham surgery. Immediately after spinal cord injury model,the elongated needle group was given the bilateral acupoints of the elongated needle penetration needling and electric stimulation, electrical stimulation 15 mm stimulation frequency of 20 to 40 times/mm, intensity 1.5 to 3 V the acupuncture group immediately was given ordinary electric needle acupuncture, given other disposals as the elongated needle group; model group was not given electric needle acupuncture, waiting 15 minutes, started to detect and record the observed indicator as the elongated needle group; the blank group was only sham surgery. The following indicators including the Tarlov score ,urinary bladder pressure point, the threshold urination, voided volume, were observed in the first day and the fifth day after surgery. RESULTS: Three groups of animals which modeled were urinary retention after operation. Compared to 1 d, Tarlov score of model group, acupuncture group and elongate needles group significantly improved at postoperative 5 d (P < 0.05). Compared with acupuncture group, the Tarlov score of elongate needles group had no significant difference at postoperative 5 d (P > 0.05). Compared with model group, values of urinary bladder pressure point decreased with varying degrees in the acupuncture group and elongate needles group at postoperative 5 d (P < 0.05); relative to the acupuncture group, the point of the bladder voiding pressure in the elongate needles group decreased more significantly at postoperative 5 d (P < 0.05); compared with model group, micturition threshold of acupuncture group and elongate needles group had been significantly improved at the fifth day after surgery (P < 0.05); relative to the acupuncture group, the improvement is more obvious in the elongate needles group. Compared with model group, voided volume of acupuncture group and elongate needles group had increased significantly at the fifth day after surgery (P < 0.05); relative to the acupuncture group, the increment is more evident in the elongate needles group (P < 0.05). CONCLUSION: To treat urinary retention after spinal cord injury, the method, which was point-through-point acupuncture with elongate needles in the "Zhibian" and "Shuidao", was better than general acupuncture method. The therapeutic mechanism may be related to stimulate peripheral nerve of bladder, and to rectify the dysfunction between detrusor and sphincter.

Difference of adherence, proliferation and osteogenesis of mesenchymal stem cells cultured on different HA/ZrO2 composites.

OBJECTIVE: To study the adherence, proliferation and osteogenesis of mesenchymal stem cells (MSCs) cultured on different HA/ZrO2 composites. METHODS: The simplex and graded HA/ZrO2 compo-sites were prepared using dry-laid method. The surface topography of the composites was observed by scanning electron microscope (SEM). The MSCs were isolated from rabbits and cultured on experimental groups (simplex HA/ZrO2 composite, graded HA/ZrO2 composite, pure HA or pure ZrO2 coatings respectively) and control group (ordinary culture plate). Then, we observed the adherence, proliferation and osteogenesis of the MSCs, detected the cellular alkaline phosphatase (ALP) activities, extracted total RNA and detected the mRNA expression of collagen I, osteocalcin and osteopontin using the reverse transcription and polymerase chain reaction (RT-PCR) method. RESULTS: The SEM images confirmed that the surface of the simplex HA/ZrO2 composite was coverd by discon-tiguous HA layer with clear visualization of the partial ZrO2 matrix, while the surface of the graded HA/ZrO2 composite was fairly rough with porosity. X-ray diffraction showed that after high temperature sintering, the ZrO2 phase still remained, while the HA phase was transformed to beta-Ca3(PO4)2 , alpha-Ca3(PO4)2 and CaZrO3 phases on the surface of both composites. Cell culture indicated that the HA/ZrO2 composites supported cell attachment. Neither ALP expression nor mRNA expression of collagen I, osteocalcin or osteopontin from RT-PCR results showed significant deviation among four groups. CONCLUSION: Among these four composites, the graded HA/ZrO2 composite promotes the MSCs proliferation and the osteogenic differentiation to a certain extent.