Excessive swelling of nerve roots : Important factor for recurring sciatica after lumbar surgery.

OBJECTIVE: The aim of the study was to investigate the occurrence of unexpectedly swollen nerve roots and to investigate the relationship between nerve root edema and recurrent radicular pain. METHODS: During the period from August 2010 to August 2015, a total of 462 patients with degenerative lumbar disease underwent surgery in this study group. Magnetic resonance imaging (MRI) was used to evaluate the details of the nerve root. Of the patients with recurring radiating pain 13 met the inclusion criteria of the study group and 24 patients without any complications volunteered as the control group. The visual analog scale (VAS), Oswestry Disability Index (ODI), and medical outcomes study item short form health survey (SF-36) were used to evaluate the clinical outcomes. RESULTS: The preoperative diameter of the nerve root showed no significant difference between the two groups (P = 0.28). The postoperative nerve diameter of the study group was larger than that of the control group (P < 0.01). The initial operation improved the symptoms and the VAS was significantly decreased (P < 0.01). After recurrence of the neuralgia, the VAS score significantly increased (P < 0.01). The pain of the study group improved to the same level as that of the control group 4 weeks after subsequent surgery (P = 0.47), while the quality of life was still lower than that of the control group (P < 0.05). The scores collected 3 months after surgery showed that the clinical outcomes were not different between the two groups (P > 0.05). CONCLUSION: In surgery for degenerative lumbar disease accompanied by nerve root edema, excessive nerve root swelling is an important factor for recurrent radiating pain. With a properly carried out intervention in the re-exploration, the recurrent symptoms can be gradually relieved.

Restoration of the spinopelvic sagittal balance in isthmic spondylolisthesis: posterior lumbar interbody fusion may be better than posterolateral fusion.

BACKGROUND CONTEXT: More and more orthopedic surgeons recognize the importance of the sagittal balance of the spine. PURPOSE: To analyze the pre- and postoperative sagittal and deformity parameters of low-grade isthmic spondylolisthesis and evaluate the effect of posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) on spinopelvic sagittal balance. STUDY DESIGN: Nonrandomized controlled prospective study with a historical control. PATIENT SAMPLE: A total of 99 patients with low-grade L5-S1 isthmic spondylolisthesis were treated surgically; 36 patients (mean age, 60.2±5.2 years) received the PLF operation, and 63 patients (mean age, 57.1±6.9 years) chose the PLIF operation. The healthy control group was composed of 60 volunteers (mean age, 44.5±8.4 years). OUTCOME MEASURES: The pre- and postoperative spinopelvic and deformity parameters. METHODS: All patients had radiographs that allowed measurement of spinopelvic parameters before and after the operation. All the spinopelvic and deformity parameters were measured. Two radiologists measured the parameters with the Cobb method. RESULTS: All of the preoperative spinopelvic parameters showed no difference between the PLIF and PLF groups in this study (p>.05). In both of the operation groups, the preoperative pelvic incidence, pelvic tilt (PT), sacral slope, lumbar lordosis (LL), and L5 incidence (L5I) were significantly higher than in the control group (p<.01); the height of the intervertebral disc (HOD) was significantly lower than the controls. There were no significant differences in PT among PLIF, PLF, and control groups after the operation (p>.05). LL increased in the PLIF group and decreased in the PLF group. The slip degree (SD) and L5I were restored significantly in both groups. The HOD of the PLIF group increased 5.04 mm, the postoperative HOD of the PLF group had no significant change. In both PLIF and PLF groups, the correction of SD was correlated with the change of LL (r=-0.398, p=.007; r=0.365, p=.022). The restoration of HOD in the PLIF group correlated with the change of LL (r=0.334, p=.011). No significant differences could be found between the short-term clinical outcomes of the PLF and PLIF. CONCLUSION: Either PLF or PLIF would lead a great change in spinopelvic parameters and deformity parameters. The decrease of PT may be an important role for the short-term surgical outcome. The PLIF could increase the LL and form a more reasonable sagittal alignment. From the point of the sagittal spinopelvic balance, the PLIF may be better than the PLF for patients with isthmic spondylolisthesis.

Changes in autophagy proteins in a rat model of spinal cord injury.

OBJECTIVE: Autophagy is involved in several neurodegenerative diseases and recently its role in acute brain injury has won increasing interest. Spinal cord injuries (SCIs) often lead to permanent neurological deficit. Therefore, in this study, we examined the pro?les of autophagy-linked proteins (MAP-LC3) after SCI to investigate whether the expression of autophagy contributes to neurological deficit after SCI. METHODS: Adult female Sprague-Dawley rats were used and randomly divided into control and SCI groups. All the rates received laminectomy at T8-T10 level. Those in the SCI group received additional exposure of the dorsal surface of the spinal cord, followed by a weight- drop injury. Thereafter we investigated the expression levels of MAP-LC3, beclin-1, Cathepsin D and the beclin-1-binding protein bcl-2 by western blot analysis at 12 h, 24 h, 3 d, 7 d, 21 d and 28 d. One-way ANOVA with Tukey post hoc test was used to compare data between groups. RESULTS: We observed significant increase in the level of LC3 (LC3-II/LC3-I) at 3 d and 7 d after SCI when compared with the sham group. While the level of beclin-1 and ratio of beclin-1/bcl-2 was found to have increased from 12 h to 24 h after injury. Cathepsin D expression was also elevated at 7 d (P<0.01). CONCLUSION: Based on the above mentioned data, we proposed that autophagy plays a role in the manifestation of cell injury following SCI.

Laminoplasty versus conservative treatment for acute cervical spinal cord injury caused by ossification of the posterior longitudinal ligament after minor trauma.

BACKGROUND CONTEXT: No reports to date have accurately evaluated the management for acute spinal cord injury (SCI) caused by ossification of the posterior longitudinal ligament (OPLL) after minor trauma. PURPOSE: To assess whether outcomes of laminoplasty is better than conservative treatment. STUDY DESIGN/SETTING: A retrospective study. PATIENT SAMPLE: Thirty-one patients underwent surgery (L group) and 29 patients underwent conservative treatment (C group). OUTCOME MEASURES: Disability, muscle strength, sensation, and general health status. METHODS: Patients were managed according to routine clinical practice and the results between groups were compared. Clinical and radiographic outcomes were assessed at admission, discharge, 6 months and at the final visit. Causes for trauma, duration of hospital stay, and complication were also evaluated. RESULTS: Causes for trauma included falling, traffic accidents and sports. Mixed and segmental types were the most frequent cause of OPLL resulting into SCI. Duration of hospital stay and complications were less in the L group. Motor and sensory scores increased in the L group at discharge (p<.05) and at 6 months (p<.05), and maintained thereafter (p>.05); scores improved significantly in the C group at 6 months (p<.05), with a slight deterioration with time (p>.05); scores in the L group were higher than in the C group at each time point after surgery (p<.05). Bodily pain and mental health in SF-36 improved at discharge in the L group (p<.05); all scores improved at 6 months in both the groups (p<.05), with better improvements in the L group (p<.05). The canal diameter increased and occupation ratio decreased in the L group (p<.05), and maintained thereafter (p<.05); a slight increase of occupation ratio was observed in the C group (p>.05). Lordotic angle and range of motion were maintained in both the groups, with no significance between groups (p>.05). High-signal intensity decreased at 6 months (p<.05) in the L group; no significant change was found in the C group during the follow-up (p>.05); Significant difference was detected between the groups at 6 months and at the final visit (p<.05). CONCLUSIONS: Most of the OPLL patients displayed as incomplete SCI after minor trauma. Although spontaneous improvement of SCI without surgery is often observed, laminoplasty has more satisfactory outcomes, prevents late compression of cord, and reduces perioperative complications, although with no significant benefit in cervical alignment and range of motion.

Influence of the posterior lumbar interbody fusion on the sagittal spino-pelvic parameters in isthmic L5-S1 spondylolisthesis.

STUDY DESIGN: Prospective study of the sagittal spino-pelvic parameters and deformity parameters in low-grade isthmic spondylolisthesis preoperation and postoperation. OBJECTIVE: To better understand how the surgery influences sagittal spino-pelvic alignment in low-grade spondylolisthesis. SUMMARY OF BACKGROUND DATA: Over the past decade, the importance of the sagittal spino-pelvic parameters was recognized. However, the postoperative change of sagittal balance parameters in low-grade spondylolisthesis was still unclear. METHODS: Forty-nine patients (mean age, 53.2±7.2 y) with low-grade L5-S1 isthmic spondylolisthesis and 60 normal volunteers (mean age, 44.5±8.4 y) were included in the study. Each subject had a radiograph that allowed measurement of sagittal spino-pelvic parameters before and after surgery. The follow-up duration was at least 2 years. Sagittal spino-pelvic parameters and deformity parameters were measured for comparison. RESULTS: Pelvic incidence, pelvic tilt (PT), sacral slope, lumbar lordosis (LL), lumbar 5 incidence, and lumbosacral angle of normal volunteers were smaller than those of spondylolisthesis patients. All of the parameters changed significantly after the posterior lumbar interbody fusion. Postoperative PT reduced by 4.9 degrees, which had no significant difference compared with the control group (P=0.601). The changes of slip degree and height of the intervertebral disk revealed correlation with the increase of LL (r=-0.483, P=0.003; r=0.365, P=0.010). CONCLUSION: The improvement of PT may play an important role in the reconstruction of the sagittal alignment and therapeutic outcome. The restoration of the slip degree and height of the intervertebral disk would increase the LL with a wedged cage. To get a better LL, the size and geometry of the cage was recommended to be evaluated before surgical treatment.

A clinical morphologic study of the C2 pedicle and isthmus.

PURPOSE: This anatomic, radiographic study investigated locational differences in the C2 pedicle and isthmus [pediculoisthmic component (PIC)] and characterized its narrowest section for clinical application in posterior C2 screw fixation. METHODS: Structures surrounding the transverse foramina of 30 dry C2s and 10 C3s were compared morphologically. Spinal CT scans of 32 Chinese adults were subjected to volume rendering and multiplanar reconstruction to identify the narrowest C2 PIC, and correlative parameters were measured and analyzed. RESULTS: Inferior C2 and C3 structures were morphologically similar. In superior view, the C2 superior facets lay on the transverse foramen and the upper portion between superior and inferior facets was flat (average mediolateral angle, 11.1° ± 2.4°). In inferior view, the posteroinferomedial portion of the C2 transverse foramen displayed a partially tubular structure (average mediolateral angle of projection, 42.6° ± 4.9°). Average height and width were 11.6 and 6.9 mm. The inner medullary cavity was elliptical and the middle site of endosteal diameter was 3.3 ± 1.9 mm. Medial internal cortical bone was significantly thicker than lateral bone (P < 0.01). CONCLUSIONS: The PIC is located between superior and inferior C2 facets. The superior flat area is the isthmus and the inferomedial area connecting the inferior facet and vertebral body is the pedicle. The pedicle is partially tubular and projects posteromedially to the transverse foramen. The narrowest PIC section is the narrowest point of the C2 pedicle. Considering its thin lateral cortical bone, medial and superior pedicle screw placement and preoperative CT reconstruction are recommended.

[SOX9 enhanced chondrogenic differentiation potential of human umbilical cord mesenchymal stem cells through cellular aggregation].

OBJECTIVE: To explore the effects of transcription factor SOX9 on chondrogenic differentiation potential of human umbilical cord mesenchymal stem cells (hUC-MSCs). METHODS: hUC-MSCs were harvested from human umbilical cord and their phenotypic characteristics identified by flow cytometry. To confirm their multipotency, hUC-MSCs were induced to differentiate toward adiposity and osteogenesis. After transfection with the packaging lentivirus vectors containing SOX9 in vitro, the expression of green fluorescent protein (GFP) and the efficiency of transfection were detected by fluorescence microscopy. Their cellular proliferation capacity was detected by thiazolyl blue tetrazolium bromide (MTT) assay.hUC-MSCs modified with SOX9 were seeded into monolayer and cultured for 21 days in a defined, serum-free medium supplemented with transforming growth factor (TGF)-ß1. The untransduced cells or those transduced with GFP served as the controls. Morphologic changes of hUC-MSCs were observed daily and their chondrogenic differentiation was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and immunofluorescent staining. And the accumulation of sulfated glycosaminoglycans was detected by Alcian blue staining. Meanwhile, the expressions of collagen I, X and cell adhesion molecule N-cadherin were assayed. RESULTS: The hUC-MSCs isolated from human umbilical cord stromas exhibited fibroblastic morphology and they were positive for CD29 (95.9%), CD44 (96.5%), CD90 (98.9%), CD105 (94.3%) and negative for hematopoietic stem cells surface markers CD34 (3.0%) and CD45 (2.6%). At Day 21, hUC-MSCs differentiated toward adiposity and osteogenesis. Both oil red O and alkaline phosphatase stains were intensely positive and it confirmed the multilineage potential of hUC-MSCs. An intense expression of GFP was observed under flourescence microscope and the transfection efficiency of cells with Lenti-GFP-SOX9 or Lenti-GFP was more than 90% respectively. SOX9 gene was over-expressed in hUC-MSCs at 48 h post-transduction. The proliferation of hUC-MSCs had no significant effect after the transfection of lentivirus vectors (P > 0.05). In vitro high-density monolayer culture of these SOX9-transfected hUC-MSCs demonstrated that spontaneous cell aggregation appeared at Day 14 of culturing and subsequently generated large cartilage nodules. However there was no phenomenon of cell aggregation occurring in the cells transducted by Lenti-GFP or untransduced vectors. The expressions of collagen II and Aggrecan were higher in SOX9 transducted cells than those in the controls. Alcian blue staining also showed abundant accumulation of sulfated glycosaminoglycans in the SOX9-induced cartilage nodules. The expression of collagen I had no difference in all groups and collagen X was inhibited in SOX9 transduced cells. N-cadherin was strongly up-regulated by SOX9 and might result in cellular aggregation and formation of large cartilage nodules. CONCLUSION: SOX9 may enhance the chondrogenic differentiation potential of human umbilical cord mesenchymal stem cells through cellular aggregation.

Protective effects of two constituents of Chinese herbs on spinal motor neurons from embryonic rats with hypoxia injury.

Neuroprotective agents are becoming significant tools in the repair of central nervous system injuries. In this study, we determined whether ginkgolides (Gin, extract of GinkgoBiloba) and Acanthopanax senticosus saponins (ASS, flavonoids extracted from Acanthopanax herbal preparations) have protective effects on rat spinal cords exposed to anoxia and we explored the mechanisms that underlie the protective effects. Spinal motor neurons (SMNs) from rat spinal cords were obtained and divided into five groups with 10 wells in each group. In control group, SMNs suffered no injury under normal oxygen; in hypoxia- inducible (HI) group, SMNs suffered injury from hypoxia; in Gin group, 37.5µg/ml Gin were used before 24 hrs of hypoxia; in ASS group, 50µg/ml ASS were used before 24 hrs of hypoxia;in glial cell-lined derived neurotrophic factor (GDNF) group, 0.1µg/ml GDNF were used before 24 hrs of hypoxia. Changes in morphology, neuron viability, and lactate dehydrogenase (LDH) release were observed. In addition, the expression of HIF-1α induced by hypoxia was measured. The neuronal viability in the Gin, ASS, and GDNF pretreated groups was higher than that in the HI group (P<0.05). The viability in the Gin group was better than that in the ASS group (P<0.05), but there was no significant difference between the ASS and GDNF groups (P>0.05). The quantity of LDH released in the three pretreated groups was lower than that in the HI group (P<0.05). The expression of HIF-1α in the HI group was greater than that in the control group (P<0.05), and the expression in the three pretreated groups was greater than that in the HI and the control groups (P<0.05). Our results indicate that Gin and ASS which was not as effective as Gin, but its effects were similar to those of GNDF could all enhance the viability of SMNs and have protective effects on hypoxic neurons.

Combination of skull traction with posterior C1-2 fusion for old C1-2 dislocations.

Between January 2003 and December 2009, 23 patients who had suffered old C1-2 dislocations, were surgically treated in our orthopedics department. Fifteen patients underwent direct posterior C1-2 fusion following pre-operative reduction by skull traction. In eight patients, reduction was achieved only by skull traction under general anesthesia, facilitated by manual hyperextension of the cervical spine and maintained by simultaneous posterior C1-2 fusion. Intra-operative traction was monitored using C-arm fluoroscopy and cortical somatosensory-evoked potentials. Posterior C1-2 fixation was achieved in nine patients using C1-2 laminar hooks and in 14 patients using C1 laminar hooks with C2 pedicle screws. During the follow-up of 5 to 72 months (mean: 42.8 months), solid bony fusion was accomplished in all patients. Using Di Lorenzo's grades and Japanese Orthopedics Association scores, there was significant improvement (p<0.05). The cervical medullary angle exhibited a significant improvement of 31.7°, from 121.6° to 153.3° (p<0.05). There were no complications, including dural tears, spinal cord damage, vertebral artery damage, or breakage or loosening of implants.

Evaluation of an injectable silk fibroin enhanced calcium phosphate cement loaded with human recombinant bone morphogenetic protein-2 in ovine lumbar interbody fusion.

The objective of this study was to investigate the efficacy of an injectable calcium phosphate cement/silk fibroin/human recombinant bone morphogenetic protein-2 composite (CPC/SF/rhBMP-2) in an ovine interbody fusion model. Twenty-four mature sheep underwent anterior lumbar interbody fusion at the levels of L1/2, L3/4, and L5/6 with random implantation of CPC/SF, CPC/rhBMP-2, CPC/SF/rhBMP-2, or autogenous iliac bone. After the sheep were sacrificed, the fusion segments were evaluated by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. The fusion rates of CPC/SF/rhBMP-2 were 55.56% and 77.78% at 6 and 12 months, respectively. The fusion was superior to all the biomaterial grafts in stiffness, and reached the same stiffness as the autograft at 12 months. The new bone formation was less than autograft at 6 months, but similar with that at 12 months. However, the ceramic residue volume of CPC/SF/rhBMP-2 was significantly decreased compared with CPC/SF and CPC/rhBMP-2 at both times. The results indicated that CPC/SF/rhBMP-2 composite had excellent osteoconduction and osteoinduction, and balanced degradation and osteogenesis.

Surgical treatment of chronic C1-C2 dislocation with absence of odontoid process using C1 hooks with C2 pedicle screws: a case report and review of literature.

STUDY DESIGN: A case report. OBJECTIVE.: A rare case of chronic C1-C2 dislocation with absence of odontoid process that underwent posterior C1-C2 arthrodesis using C1 hooks and C2 pedicle screws. SUMMARY OF BACKGROUND DATA: C1-C2 dislocation is a rare but fatal upper cervical injury. To date, there have been many reports about C1-C2 dislocation of traumatic origin. However, very few C1-C2 dislocation cases of congenital odontoid deformities had been presented. This was particularly the case when the odontoid process was absent. METHODS: Plain radiograph of his cervical spine revealed a C1-C2 dislocation, and subsequent computed tomographic scan as well as magnetic resonance imaging (MRI) detected absence of odontoid process and cord compression. Upon admission, the patient was placed on skull traction and the weight increased from 3.5 to 5.5 kg. After 10 days of traction, reduction was achieved radiographically and the posterior C1-C2 arthrodesis by C1 hooks with C2 pedicle screws was performed. RESULTS: After surgery, the patient showed significant improvement in gait function despite slightly raised muscle tone in his lower extremities. Four-month postoperative radiographs indicated restoration of C1-C2 alignment and bony fusion. No residual cord compression was present. CONCLUSION: In clinical evaluation of patients who present with neck pain and limited cervical motion with or without neurologic deficits, C1-C2 dislocation should be considered. If the patient has no history of trauma or infection, congenital C1-C2 deformity, especially odontoid malformation, has to be included as a possible factor. Once the diagnosis is confirmed, posterior C1-C2 arthrodesis may become necessary for stabilizing C1-C2 and preventing it from deterioration or new development of neurologic symptoms.

Outcome of thoracolumbar burst fractures treated with indirect reduction and fixation without fusion.

Indirect reduction and fixation is not a new method in the treatment of thoracolumbar burst fractures but the indications and efficacy are controversial. The current study was designed to evaluate the efficacy of indirect reduction without fusion. Sixty-four patients with single-level thoracolumbar burst fractures were identified and treated by this method. The outcome was analyzed by the Frankel method, radiographic measurements, and at the latest follow-up the Denis Pain Scale and Oswestry disability index (ODI) were used to assess back pain and functional outcome. The average follow-up period was 40.1 months. The anterior vertebral height (AVH) was corrected from 55.2 to 97.2% post-operatively and decreased to 88.9% after hardware removal. The posterior vertebral height (PVH) increased from 88.9 to 99.1% post-operatively and decreased slightly after implant removal to 93.7%. The average pre-operative canal compromise was 41.4%, which decreased to 13.7% at last follow-up. Except for three paraplegic patients, neurological status significantly improved or stayed normal in the study's remaining 61 patients. Fifty-two of sixty-four patients had excellent or good function. At latest follow-up the average ODI score was 16.7 and the Denis pain score improved in all patients but one. Indirect reduction and fixation can not only restore vertebral column structure but also, more importantly, patients' functional outcome.

Spinal extradural arachnoid cyst following percutaneous vertebroplasty.

We report a rare complication of extradural arachnoid cyst following percutaneous vertebroplasty in a spinal metastasis patient. Percutaneous vertebroplasty has been established as a safe and effective treatment for osteoporotic vertebral fractures and vertebral metastatic lesions. To our knowledge, extradural arachnoid cyst following vertebroplasty has not been reported in literature. A 48-year-old woman diagnosed with adenocarcinoma underwent percutaneous vertebroplasty at the L3 vertebral level due to painful solitary spinal metastasis. At 5 months after surgery, the patient complained of low back pain radiating to the left lower extremity. MRI showed a large cystic lesion in the spinal canal at the L2-L3 level with compression to adjacent dura sac. On T1- and T2-weighted images, the signal within the cyst had the same intensity as cerebrospinal fluid. The patient underwent laminectomy for excision of the extradural cyst. Intraoperatively, a small communication between the cyst and the subarachnoid space was seen at the level of the L3 pedicle. Pathological examination revealed that the cyst wall was composed of non-specific fibrous connective tissue and the content of the cyst was the same as that of cerebrospinal fluid. Postoperatively, the patient's symptom was relieved immediately. The iatrogenic dural injury produced by puncture of the pedicle during vertebroplasty may be the cause of formation of the extradural arachnoid cyst.

Comparison of the mini-midvastus with the mini-medial parapatellar approach in primary TKA.

A prospective randomized study was performed to compare the clinical and radiological results of primary total knee arthroplasties (TKAs) using a mini-midvastus approach or a mini-medial parapatellar approach in 134 patients. The mini-midvastus approach was used on 68 patients (group A) and the mini-medial parapatellar approach on 66 patients (group B). All knees were implanted with the same posterior-stabilized prosthesis by the same surgeon (T.-S.T.) with the same set of downsized instruments. Mean follow-up in both groups was 30.5 months (range, 24-48 months). Patients in group A achieved an active straight-leg raise and 90° of flexion significantly earlier (P=.017 and P=.025, respectively). However, no significant difference was detected between the groups with respect to range of movement and Knee Society scores at all the postoperative visits and at final follow-up (all, P>.05). In contrast, the tourniquet time was significantly longer in group A (P=.015), with a higher incidence of medialized tibial component (P=.031). We believe that the early clinical results are similar between the mini-midvastus and mini-medial parapatellar approach. The mini-medial parapatellar approach is easier to initially apply and provides better visualization for TKA.

[Balloon kyphoplasty for osteoporotic vertebral compression fractures with osteonecrosis].

OBJECTIVE: To explore the clinical efficacy of the percutaneous balloon kyphoplasty for osteoporotic vertebral compression fractures with osteonecrosis. METHODS: The clinical data of 31 patients with osteoporotic vertebral compression fractures associated with osteonecrosis from January 2005 to January 2008 were analyzed retrospectively. There were 13 male and 18 female in this study. The mean age of the patients was 71 years (range from 57 to 84 years). The back pain lasted for 4.2 months (from 1 month to 10 years). Radiography, MRI and CT examination were performed. The patients were treated by percutaneous balloon kyphoplasty and the vertebral body tissue was extracted to perform common pathological examination. The anterior vertebral height was measured on a standing lateral radiograph before operation, after operation (one day after operation) and at the final follow-up. A Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI) were chosen to evaluate pain status and functional activity. RESULTS: The mean follow-up was for 27 months (range, 18 to 48 months). The anterior vertebral body height of fracture vertebra was restored from (34.7 +/- 3.1)% preoperatively to (71.4 +/- 2.3)% postoperatively, and to (70.2 +/- 2.5)% at the final follow-up. There was a significant improvement between preoperative and postoperative values (P < 0.05) and no difference between postoperatively and at the final follow-up (P > 0.05). The VAS was 8.7 +/- 0.4 preoperatively, 2.3 +/- 0.7 postoperatively, and 1.9 +/- 0.2 at the final follow-up; and the ODI was 89.1 +/- 2.7 preoperatively, 31.7 +/- 3.1 postoperatively, and 29.1 +/- 2.7 at the final follow-up. There was statistically significant increment in the VAS and ODI postoperatively compared with preoperatively (P < 0.05), while there was no statistically significant differences between postoperatively and at the final follow-up (P > 0.05). There was a significant increment between preoperative and final follow-up values (P < 0.05). Asymptomatic cement leakage occurred in two cases. New vertebral fracture occurred in one case. CONCLUSION: Balloon kyphoplasty is a safe and effective procedure for osteoporotic vertebral compression fractures with osteonecrosis.

[Open-door laminoplasty for the treatment of failed anterior cervical spine surgery].

OBJECTIVE: To evaluate the outcome of open-door laminoplasty for the treatment of failed anterior cervical spine surgery. METHODS: From February 2003 to June 2009, 15 patients underwent open-door laminoplasty for the failed anterior cervical spine surgery. The causes of revision and the progression of disease were analyzed. Japanese Orthopedic Association (JOA) scores and Nurick grade were adopted to record the improvement of neurological status and walking ability. RESULTS: Two patients were excluded for analysis because of lost follow-up and follow-up less than 12 months. The mean follow-up period after revision surgery for the other 13 patients was 26 months (ranged 13-52 months). The mean interval between the initial and revision surgery was 24 months (ranged 5 months to 6 years). The causes of revision were as following: degeneration of the adjacent segment in 2 cases, inadequate decompression in 5 cases, mis-diagnosis of ossification of posterior longitudinal ligament (OPLL) as myelopathy in 4 cases, and progression of OPLL in 2 cases. Posterior laminoplasty was recommended for each patient. After the operation, 13 patients improved neurologically with respect to JOA score, 12 patients improved their walking ability while 1 remained unchanged. The mean modified JOA scores improved from 10.5 to 13.8 (P<0.05), the average recovery rate was 53.0% after the revision operation. The mean overall Nurick grade was 3.1 preoperatively and 1.9 at the final follow-up (P<0.05), the mean improvement of the Nurick grade was 1.2. Complications included cerebrospinal fluid leakage in 1 case, new axial neck pain in 1 case, and transient C5 nerve root palsy in 1 case. CONCLUSIONS: Open-door laminoplasty is a straightforward and effective treatment for failed anterior cervical spine surgery due to inadequate decompression, progressive OPLL or degeneration of the adjacent segment. The merit of the open-door laminoplasty for failed anterior spine fusion is able to avoid high risk from initial anterior cervical spine surgery.

[Construction of lentiviral vector containing SOX9 gene and its expression in bone marrow mesenchymal stem cells].

OBJECTIVE: To construct the lentiviral vector containing SOX9 gene and to detect its expression in MSCs derived from rabbit bone marrow. METHODS: Human sox-9 gene coding region fragment was obtained by RT-PCR (reverse transcription-polymerase chain reaction) and then cloned into the plasmid of Pwpxl-MOD2 to form Pwpxl-MOD2/SOX9. Pwpxl-MOD2/SOX9, pRsv-REV, pMDlg-Prre and pMD2G were co-transfected into 293T cells to obtain recombinant virus containing SOX9 gene. Meanwhile, Pwpxl-MOD2, pRsv-REV, pMDlg-pRRE and pMD2G were transfected into another group of 293T cells as a control group packing into blank lentiviral vector. Then the packed lentiviral vector was transfected into MSCs which derived from rabbit bone marrow. The expression of SOX9 was detected by both RT-PCR and Western blot. Identification and proliferation of MSCs was determined by MTT after transfection. RESULTS: The sequencing and restriction analysis showed that SOX9 gene fragment was correctly connected and cloned into the plasmid Pwpxl-MOD in lentiviral vectors. After transfection, the expression of SOX9 gene in MSCs was confirmed by RT-PCR and Western blot. MTT showed the growth of MSCs had no significant effect after transfection with lentiviral vector. CONCLUSION: Lentiviral vector carrying SOX9 gene has been successfully constructed. There is a stable expression in transfected MSCs. Thus it will facilitate the exploratory development of gene and biological therapy for intervertebral disc degeneration.

Results after surgical treatment of transtectal transverse acetabular fractures.

OBJECTIVE: To retrospectively evaluate the results of operative treatment of transtectal transverse fractures of the acetabulum. METHODS: From May 1990 to July 2006, 40 patients with displaced transtectal transverse fracture of the acetabulum were treated surgically. A mean postoperative follow-up of 88.6 months' (range, 16-121 months) was achieved in 37 patients. Final clinical results were evaluated by a modified Merle d'Aubigné and Postel grading system. Postoperative radiographic results were evaluated by the Matta criteria. Fracture and radiographic variables were analyzed to identify possible associations with clinical outcome. RESULTS: Fracture reduction was graded as anatomic in 31 patients, imperfect in 4 and unsatisfactory in 2. Two hips were diagnosed to have subtle instability by postoperative radiography. The clinical outcome was graded as excellent in 16 patients, good in 14, fair in 4 and poor in 3. The radiographic result was graded as excellent in 14 patients, good in 15, fair in 4 and poor in 4. There was a strong association between the final clinical and radiographic outcomes. Variables identified as risk factors for unsatisfactory results included residual displacement greater than 2 mm, comminuted fracture of the weight bearing dome, postoperative subtle hip instability and damage to the cartilage of the femoral head. CONCLUSION: The uncomplicated radiographic appearance of transtectal transverse fracture belies its complexity. Comminuted fracture of the weight bearing dome, unsatisfactory fracture reduction, subtle hip instability and damage to the cartilage of the femoral head are risk factors for the clinical outcome of transtectal transverse fracture of the acetabulum.

Use of an integrated anterior cervical plate and cage device (PCB) in cervical anterior fusion.

The aim of this study is to evaluate an integrated cage and plate device (the plate cage Benezech, PCB) filled with autogenous bone in anterior cervical discectomy and fusion. The fused segment height, lordosis, and fusion were assessed by postoperative radiographic examination at different intervals. Patients were evaluated using Odom's criteria and the Short Form (SF)-36 Health Survey questionnaire. The mean follow-up duration was 4.1 years. Fusion was achieved in 90.0%, 96.0% and 100% of patients at 3 months, 6 months and at final visit, respectively. The fused segment height and lordosis were restored and maintained. Cage subsidence (3mm) occurred at one level and settling was observed at three levels. An excellent-to-good result was achieved in 81.8% of patients. The data from the SF-36 questionnaire revealed significant postoperative improvement (p<0.01) except for social function and mental health. This study suggests that patients instrumented with PCB can obtain good radiographic and clinical results and that PCB is a safe and effective device in cervical anterior fusion.