Identifying the Characteristics of Patients With Cervical Degenerative Disease for Surgical Treatment From 17-Year Real-World Data: Retrospective Study.

BACKGROUND: Real-world data (RWD) play important roles in evaluating treatment effectiveness in clinical research. In recent decades, with the development of more accurate diagnoses and better treatment options, inpatient surgery for cervical degenerative disease (CDD) has become increasingly more common, yet little is known about the variations in patient demographic characteristics associated with surgical treatment. OBJECTIVE: This study aimed to identify the characteristics of surgical patients with CDD using RWD collected from electronic medical records. METHODS: This study included 20,288 inpatient surgeries registered from January 1, 2000, to December 31, 2016, among patients aged 18 years or older, and demographic data (eg, age, sex, admission time, surgery type, treatment, discharge diagnosis, and discharge time) were collected at baseline. Regression modeling and time series analysis were conducted to analyze the trend in each variable (total number of inpatient surgeries, mean age at surgery, sex, and average length of stay). A P value <.01 was considered statistically significant. The RWD in this study were collected from the Orthopedic Department at Peking University Third Hospital, and the study was approved by the institutional review board. RESULTS: Over the last 17 years, the number of inpatient surgeries increased annually by an average of 11.13%, with some fluctuations. In total, 76.4% (15,496/20,288) of the surgeries were performed in patients with CDD aged 41 to 65 years, and there was no significant change in the mean age at surgery. More male patients were observed, and the proportions of male and female patients who underwent surgery were 64.7% (13,126/20,288) and 35.3% (7162/20,288), respectively. However, interestingly, the proportion of surgeries performed among female patients showed an increasing trend (P<.001), leading to a narrowing sex gap. The average length of stay for surgical treatment decreased from 21 days to 6 days and showed a steady decline from 2012 onward. CONCLUSIONS: The RWD showed its capability in supporting clinical research. The mean age at surgery for CDD was consistent in the real-world population, the proportion of female patients increased, and the average length of stay decreased over time. These results may be valuable to guide resource allocation for the early prevention and diagnosis, as well as surgical treatment of CDD.

Langerhans cell histiocytosis with multiple spinal involvement.

To stress the clinical and radiologic presentation and treatment outcome of Langerhans cell histiocytosis (LCH) with multiple spinal involvements. A total of 42 cases with spinal LCH were reviewed in our hospital and 5 had multifocal spinal lesions. Multiple spinal LCH has been reported in 50 cases in the literature. All cases including ours were analyzed concerning age, sex, clinical and radiologic presentation, therapy and outcome. Of our five cases, three had neurological symptom, four soft tissue involvement and three had posterior arch extension. Compiling data from the eight largest case series of the spinal LCH reveals that 27.2% multiple vertebrae lesions. In these 55 cases, there were 26 female and 29 male with the mean age of 7.4 years (range 0.2-37). A total of 182 vertebrae were involved including 28.0% in the cervical spine, 47.8% in thoracic and 24.2% in the lumbar spine. Extraspinal LCH lesion was documented in 54.2% cases, visceral involvement in 31.1% and vertebra plana in 50% cases. Paravertebral and epidural extension were not documented in most cases. Pathological diagnosis was achieved in 47 cases including 8 open spine biopsy. The treatment strategy varied depending on different hospitals. One patient died, two had recurrence and the others had no evidence of the disease with an average of 7.2 years (range 1-21) of follow-up. Asymptomatic spinal lesions could be simply observed with or without bracing and chemotherapy is justified for multiple lesions. Surgical decompression should be reserved for the uncommon cases in which neurologic compromise does not respond to radiotherapy or progresses too rapidly for radiotherapy.

Simvastatin induces estrogen receptor-alpha expression in bone, restores bone loss, and decreases ERα expression and uterine wet weight in ovariectomized rats.

We previously reported that simvastatin induces estrogen receptor-alpha (ERα) in murine bone marrow stromal cells in vitro. In this study, we investigated the effect of simvastatin on ERα expression in bone and uterus in ovariectomized (OVX) rats and evaluated bone mass, bone strength, and uterine wet weight. Three-month-old Sprague-Dawley female rats received OVX or sham operation. Six weeks later, the rats were treated orally with simvastatin (5 or 10 mg/kg/day), or intraperitoneally with 17-ß-estradiol (E(2)) or a combination of simvastatin and E(2) for 6 weeks. Uterine wet weight, bone mineral density (BMD) of lumbar vertebrae, biomechanics of lumbar vertebrae, and induction of ERα expression in the bone and uterus were analyzed. The 6-week simvastatin treatment improved lumbar vertebral BMD and boosted biomechanical performance of the vertebral body compared to the OVX control, suggesting that simvastatin can treat osteoporosis caused by estrogen deficiency. More interestingly, simvastatin could increase ERα expression and synergy with estradiol in bone while antagonizing estradiol in the uterus, along with uterus atrophy and uterine wet weight decreases. In conclusion, these data suggest that simvastatin exert opposing modulatory effects on ERα expression on bone and uterus in ovariectomized rats, inducing ERα expression and synergy with estrogen to perform anabolic effects on the bones while decreasing E2 efficacy and uterine wet weight. This finding may be helpful to explain the mechanism of statin treatment in osteoporosis caused by estrogen deficiency.

Differential proteomic profiling of chordomas and analysis of prognostic factors.

BACKGROUND: The recurrence rate of chordoma is high, and the prognosis is poor. METHODS: Differential proteomic analysis was performed on chordomas and adjacent normal tissues, with verification by Western blot. Protein expression was evaluated by immunohistochemistry of 37 chordomas. Association of candidate protein expression with clinical parameters, disease-free survival, and overall survival were analyzed. RESULTS: We identified 14 up-regulated and 5 down-regulated proteins in chordomas. Expression of alpha enolase (ENO1), pyruvate kinase M2 (PKM2), and gp96 was higher in recurrences than in primary tumors. Univariate analysis showed that significantly adverse factors for disease-free survival were overexpression of ENO1 and PKM2, involvement of contiguous vertebral levels, and inadequate surgical margin at initial surgery. Inadequate surgical margin without radiotherapy, involvement of contiguous vertebral levels, and cervical spine location were adverse factors for overall survival. By multivariate analysis, independent adverse prognostic factors were inadequate surgical margin and involvement of multiple contiguous vertebral levels for recurrence; upper cervical spine location and involvement of contiguous vertebral levels for tumor-related death. Multivariate analysis failed to show the significance of the proteins. CONCLUSIONS: Involvements of multiple contiguous vertebral levels and upper cervical spine, rather than overexpression of ENO1, PKM2, or gp96, are independent prognostic indicators for chordomas.

Langerhans cell histiocytosis of the cervical spine: a single Chinese institution experience with thirty cases.

STUDY DESIGN: A retrospective study of cervical Langerhans cell histiocytosis (LCH). OBJECTIVE: To evaluate the safety and efficiency of the present diagnosis and treatment strategy. SUMMARY OF BACKGROUND DATA: The diagnosis and treatment protocols are still controversial for the rarity of cervical LCH. METHODS: Thirty patients with cervical LCH were diagnosed in the past 10 years. Biopsy was routinely performed to establish the final diagnosis before treatment. Immobilization was usually the first choice. Low-dose radiotherapy was suggested for cases with solitary marked bony erosion and/or soft tissue extension, and chemotherapy for cases with multiple lesions. Surgery was preserved for suspected malignancy, neurologic deficits, severe deformity, and/or instability. RESULTS: The mean age at diagnosis was 14.2 (range: 1.5-41) years old. Neck pain (96.7%) was the most common symptom, followed by restricted motion (70%), neurologic symptoms (36.7%), and torticollis (30%). Four cases had multiple lesions. Fourteen cases had atlantoaxial lesion and 16 cases were subaxial. The lesion extended to paravertebral soft tissue in 40% cases, to epidural space in 30%, to pedicle and/or transverse process in 56.3%. One case had endplate destruction. The accuracy of percutaneous needle biopsy under CT guidance was 91.2%. Eighteen patients had conservative treatment and 12 underwent operation. Three cases involving C2 vertebral body had fixed atlantoaxial anterior dislocation. Another 3 cases with atlantoaxial lateral mass destruction had spontaneous fusion. Eighteen patients had conservative treatment (1 only by immobilization, 13 by radiotherapy, 2 by chemotherapy, and 2 by combined chemotherapy and radiotherapy) and 12 underwent operation. All the initial symptoms were resolved, and there was no recurrence. From retrospective view, the surgical procedure might be avoided in 60% cases. Twenty-five cases had an average 61.6-month follow-up. In cases with severe bony collapse, the vertebral height ratio increased from 20.0% to 44.9% and the lateral mass height ratio from 22.2% to 56.8%. CONCLUSION: Cervical LCH lesions often extend to paravertebral soft tissue, epidural space, pedicles, and even to the endplate and lamina. Needle biopsy under CT guidance is safe and effective. The prognosis of cervical LCH is generally fair. Conservative treatment is usually enough and surgery should be reserved for major neurologic defects like myelopathy or monoparesis.

Langerhans cell histiocytosis of the atlas in an adult.

Langerhans cell histiocytosis (LCH), formerly known as histiocytosis X, is a rare disorder (approximately 1:1,500,000 inhabitants) characterized by clonal proliferation and excess accumulation of pathologic Langerhans cells causing local or systemic effects. The exact etiology of LCH is still unknown. LCH could affect patients of any age, although most present when they are children. The most frequent sites of the bony lesions are the skull, femur, mandible, pelvis and spine. A variety of treatment modalities has been reported, but there was no evidence suggesting that any one treatment was more advantageous than another. We present an adult with LCH of the atlas. A 26-year-old young man presented with a 2-month history of neck pain and stiffness. CT revealed osteolytic lesion in the left lateral mass of atlas with compression fracture. Histopathological diagnosis was Langerhans cell histiocytosis by percutaneous needle biopsy under CT guidance. The patient underwent conservative treatment, including Halo-vest immobilization and radiotherapy. At 7-year follow-up, the patient was asymptomatic except for mild motion restriction of the neck. CT revealed a significant reconstruction of the C1 lateral mass.

Results of surgical treatment of cervical dumbbell tumors: surgical approach and development of an anatomic classification system.

STUDY DESIGN: A retrospective study of a new classification and surgical approach of cervical dumbbell tumors. OBJECTIVE: To evaluate PUTH classification. SUMMARY OF BACKGROUND DATA: The high recurrence rate and postoperative deformity are unsolved problems. Asazuma's landmark classification could not cover all cases and could not provide clear suggestion for the surgical approach. The ideal classification should be comprehensive, easily understood and of practical value. METHODS: PUTH classification for cervical dumbbell tumors includes 7 categories (types 1-7) and 2 foraminal modifiers. Posterior approach is appropriate for type 1, 2 and 5 tumors, anterior and anterolateral approach is an ideal choice for type 4 and 6 tumors. Type 7 tumors need combined anterior and posterior approach. RESULTS: Forty-four consecutive patients with cervical dumbbell tumor were surgically treated. The pathology included schwannoma in 31 cases, neurofibroma in 9 and ganglioneuroma in 4. Based on PUTH classification, type 3 was diagnosed in 13 cases, type 5 in 17, type 6 in 8, and type 7 in 6. Tumors were unilateral in 41 cases, and bilateral in 3 cases. Five were tumor revision cases. Thirty patients underwent posterior approach, 7 had anterior approach, 1 had anterolateral approach, and 6 had combined approach. Gross total resection was achieved in all the patients. Tumors involved nerve roots were transected in 12 cases. Single vertebral artery was ligated in 3. The complications included cerebrospinal fluid leakage in 18 cases, esophagus injury in 1, Horner syndrome in 1, dysphagia in 2, dyspnea in 1 and deep infection in 1. Thirty-six cases (81.1%) had an average 61-month follow-up. Recurrence was found in only one case (2.8%). CONCLUSION: PUTH classification covers all tumor types and is easier to remember. It is practical and useful for determining the surgical approach. The recurrence rate decreases significantly after radial tumor resection. Revision surgeries are associated with more complications.

Upper cervical spine chordoma of C2-C3.

Chordoma is a rare low-grade malignant neoplasm derived from the remnants of the embryonic notochord. This locally invasive neoplasm is subject to recurrence after treatment. The median survival time is estimated to be 6.3 years. Various treatment approaches have been attempted, including radical excision, radiotherapy and chemotherapy. Treatment outcome is significantly influenced by the size and site of the chordoma. Recently, Imatinib, a molecular-targeted agent, has been shown to have antitumor activity in chordoma. Proton radiotherapy, stereotactic radiotherapy and intensity-modulated radiotherapy have also been used. Surgical treatment is still the primary choice for chordoma. It has become more aggressive in recent years, evolving from intralesional or partial excision to en bloc resection. However, upper cervical localizations make such en bloc resection in most cases not possible. We present and discuss the therapeutic challenges of a young female with large retropharyngeal chordoma who presented to our institution after conventional photon beam radiotherapy. This C2/3 tumor was classified IB according to the Enneking classification. It distributed to layers A-D and sectors 1-6 according to the Weinstein Boriani Biagini Classification. The left vertebral artery (VA) was encapsulated and displaced. One stage intralesional extracapsular tumor excision and reconstruction was achieved by combined bilateral high anterior cervical approaches and posterior approach. No recurrence or metastasis was observed 3 years after the operation. She returned to her previous occupation as office worker.

[Analysis of veracity of the C1 lateral mass screw insertion in the atlantoaxial fixation].

OBJECTIVE: To evaluate the veracity of the C1 lateral mass screw insertion in the atlantoaxial fixation using plate and screw method without A-P fluoroscopic guiding. METHODS: In the atlantoaxial fixation, without A-P fluoroscopic guiding, we probe lateral mass edge and identify the entrance point of C1 lateral mass screw indirectly. 159 patients treated with atlantoaxial fixation using plate and screw method were studied. Postoperative CT was used for analysis, and the position of the lateral mass screws in atlas was identified by coronary and axial CT scan. Three areas were delimited in and around the lateral mass of atlas in the axial CT scan, so as to analyze the location of screws: area A (inside the joint face), area B (outside the joint face but still in lateral mass), and area C (outside the lateral mass). RESULTS: Among the 318 screws, 308 (96.9%) were located in area A, 5 in area B (1.6%), and 5 in area C (1.6%). All cases got atlantoaxial union at 4 months after operation. CONCLUSION: Probing lateral mass edge and identifying the lateral mass indirectly is reliable for identifying the path of screw in atlas.

[Qualitative diagnosis and therapeutic strategy of atlanto-axial tuberculosis].

OBJECTIVE: To investigate the qualitative diagnosis method of atlanto-axial tuberculosis and the corresponding therapeutic strategy. METHODS: Twenty-two cases with atlanto-axial tuberculosis proven by histopathologic diagnosis were observed. Three cases and 17 cases underwent trans-oral biopsy and CT-guide percutaneous biopsy respectively, 2 cases were conformed by frozen section in operation. Thirteen of the 22 cases underwent surgical therapy: 1 case with anterior trans-oral radical eradication and fusion under Halo-vest immobilization, 7 cases with anterior cervical radical eradication, 1 case with anterior interbody fusion and titanic plate fixation, 2 cases were with posterior atlantoaxial interlaminar fusion and 2 cases with posterior cervical occipito-axial titanic plate internal fixation and fusion. Other 9 cases accepted nonsurgical therapy: 8 cases with Halo-vest immobilization and 1 case with head halter traction. All cases were given appropriate antituberculotic chemotherapy for 12-18 months. RESULTS: All of the 22 cases were followed up, and the average time was 37 month. The lesion focus showed reparation and fusion in X-ray, and the results were satisfactory. CONCLUSIONS: Biopsy can acquire the qualitative diagnosis on atlanto-axial tuberculosis. The choice of therapy is made on the situation of cold abscess, pathological fracture, atlanto-axial dislocation and spinal cord compression.

Icariine stimulates proliferation and differentiation of human osteoblasts by increasing production of bone morphogenetic protein 2.

BACKGROUND: Icariine is a flavonoid isolated from a traditional Chinese medicine Epimedium pubescens and is the main active compound of it. Recently, Epimedium pubescens was found to have a therapeutic effect on osteoporosis. But the mechanism is unclear. The aim of the study was to research the effect of Icariine on the proliferation and differentiation of human osteoblasts. METHODS: Human osteoblasts were obtained by inducing human marrow mesenchymal stem cells (hMSCs) directionally and were cultured in the presence of various concentrations of Icariine. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) test was used to observe the effect of Icariine on cell proliferation. The activity of alkaline phosphatase (ALP) and the amount of calcified nodules were assayed to observe the effect on cell differentiation. The expression of bone morphogenetic protein 2 (BMP-2) mRNA was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Icariine (20 microg/ml) increased significantly the proliferation of human osteoblasts. And, Icariine (10 microg/ml and 20 microg/ml) increased the activity of ALP and the amount of calcified nodules of human osteoblasts significantly (P < 0.05). BMP-2 mRNA synthesis was elevated significantly in response to Icariine (20 microg/ml). CONCLUSIONS: Icariine has a direct stimulatory effect on the proliferation and differentiation of cultured human osteoblast cells in vitro, which may be mediated by increasing production of BMP-2 in osteoblasts.

Treatment of cervical dislocation with locked facets.

BACKGROUND: Lower cervical dislocation with locked facets is common in cervical injury. The locked facets include unilateral and bilateral types. Different successful closed reduction rates has been achieved between unilateral and bilateral types by using rapid skull traction, which was commonly used to reduce the cervical dislocation. It is important to investigate a suitable management specific to patients with different types of cervical locked facets. METHODS: A total of 38 patients with cervical dislocation with locked facet due to cervical injury treated by rapid skull traction and operation from 1988 to 2005 were reviewed. Rapid skull traction was used in all the patients. Successful closed reduction rate was 88.0% in patients with bilateral cervical locked facets and that was 15.4% in those with unilateral cervical locked facets. These data were then statistically compared by Chi-square test. Patients who were reduced successfully underwent anterior cervical discectomy and fusion at the injured level, and those who failed in closed reduction received posterior open reduction and fixation. RESULTS: In this series, there was statistically significant difference (P < 0.05) in the rate of successful closed skull traction reduction between unilateral and bilateral locked facets dislocation. Unilateral cervical locked facets dislocation was not easily reduced by skull traction which was suitable for reduction of bilateral cervical locked facets dislocation. However, unilateral cervical locked facets dislocation can be reduced by posterior open reduction. CONCLUSIONS: Unilateral cervical locked facets dislocation should be treated immediately with posterior open reduction and instrumentation. Bilateral cervical locked facets dislocation can be reduced by rapid skull traction firstly and anterior cervical discectomy and interbody fusion later.

[Single-stage combined anterior-posterior instrumentation for multiple level cervical spine fractures].

OBJECTIVE: To investigate the efficacy of single-stage combined anterior-posterior instrumentation for treatment of multiple level cervical spine fractures. METHODS: Nine patients with multiple-level fractures of the cervical spine, 8 males and 1 female aged 24 - 63, underwent ingle-stage combined anterior-posterior instrumentation. Seven patients with multiple contiguous fractures of the cervical spine were treated with anterior decompression and plating combined with posterior cervical lateral mass screw fixation; and 2 patients with non-contiguous cervical fractures, both with type II odontoid fracture and lower cervical fracture, were treated with both anterior odontoid screw and posterior cervical lateral mass screw fixation. Cranioskeletal traction with a weight of 5 kg was done before the operation. Follow-up was conducted for 31 months. ASIA motor scores were used to evaluate the neural function. RESULTS: Satisfactory reduction and fusion were obtained without any complication, and the neural function was improved. Nerve root function recovered in two patients and one patient's spinal cord function became normal. The average ASIA score was 63.8. CONCLUSION: A feasible option in the treatment of multiple level cervical spinal fractures, single-stage combined anterior-posterior instrumentation provides decompression and stabilization in a short time and helps the neural function to recover.

[The effect of early diagnosis of recurrence and revision after resection of primary spine tumors].

OBJECTIVE: To explore the effect of early diagnosis of recurrence and early revision after resection of primary spine tumors. METHODS: From March 1989 to September 2005, the relate clinic data of 55 patients with giant cell tumors, osteoblastomas, chondrosarcomas and chordomas in spine in big piecemeal and current fashion was analysed. RESULTS: In 55 cases, 43 patients were followed up and had complete materials. The follow-up time ranged from 1.6 to 16.5 years, averagely 5.8 years. Thirty-four patients followed up regularly, and 12 were found recurrent, in which one C(1) giant cell tumor was found extensively large 3 months after initial surgery and was undertaken palliatory curet. The other eleven lesions were small and re-operated with wide margin. As a result, six patients lived without tumors during the 1 approximately 9.5 years follow-up, one patient gave up revision when found recurred again for economic reason, another four patients recurred repeatedly, but they persisted in regular follow-up and took revision surgeries whenever the recurred lesion were found. As a result, 3 of them lived without tumor and the other one died of other disease without sign of recurrence. In contrast, there were another nine patients who came to follow up until they had symptoms and were confirmed recurrent extensively. Two of them were excised radically for the tumors located in the relatively easily exposed segments of spine and lived without tumor now. While the other seven patients only received palliatory curet and all died of tumors. CONCLUSIONS: Regular follow-up, early diagnosis of recurrence and early revision need to be regarded as part of radical excision and are very important of surgical treatment of spinal tumors, which can prolong the patients' survival time.

[Lumbar interbody fusion using autologous bone marrow mesenchymal stem cell-calcium phosphate ceramic composite in rhesus monkey].

OBJECTIVE: To determine the osteogenic capacity of autologous bone marrow mesenchymal stem cells (BMSCs)-calcium phosphate ceramic composites in vitro and implanted as a bone graft substitute for lumbar anterior interbody fusion in rhesus monkeys. METHODS: From March 2003 to April 2005, 9 adult rhesus monkeys underwent lumbar L(3 - 4) and L(5 - 6) discectomy and interbody fusion via an anterior retroperitoneal approach. Two fusion sites in each animal were randomly assigned to two of three treatments: autogenous tricortical iliac crest bone graft (autograft group, n = 6) or cell-free ceramic graft (ceramic group, n = 6) or BMSCs-ceramic composite graft (BMSCs group, n = 6). Autologous BMSCs were culture-expanded and stimulated with osteogenic supplement. The cell-ceramic composites were constructed in a rotary dynamic cell culture system. The spinal fusion segments were evaluated by radiography, biomechanical testing, histologic analysis and histomorphometric analysis at 3 months post-surgery. RESULTS: Biomechanical testing showed that spinal segments from the autograft group and the BMSCs-ceramic group were statistically and significantly stiffer than the cell-free ceramic group. The BMSCs-ceramic group and the autograft group showed equivalent biomechanical stiffness by statistical analysis. Histologically, both the autograft group and the BMSCs-ceramic group achieved osseous union, but the cell-free ceramic group had a fibrous union. Quantitative histologic analysis showed that the amount of bone formation was significantly greater in the autograft group and the BMSCs-ceramic group compared with the cell-free ceramic group. However, the amount of ceramic residue was significantly greater in the cell-free ceramic group versus the BMSCs-ceramic group. CONCLUSIONS: The results indicate that BMSC-ceramic composites can enhance bone regeneration and achieve osseous spinal fusion 3 months after the implantation in rhesus monkey interbody fusion model. Cell-free ceramics has an unsatisfactory efficacy in spinal fusion due to its tense fibrous fusion.

Open reduction of irreducible atlantoaxial dislocation by transoral anterior atlantoaxial release and posterior internal fixation.

STUDY DESIGN: A retrospective study of surgical outcome of 33 patients with irreducible atlantoaxial dislocation (IAAD). OBJECTIVE: To evaluate the safety efficacy of one stage anterior release and posterior fixation and fusion to reduce and stabilize IAAD. SUMMARY OF BACKGROUND DATA: The traditional treatment of symptomatic IAAD is ventral decompression by transoral approach. This procedure is accompanied with high morbidity and mortality. It does not correct the swan neck deformity, which could precipitate the degenerative changes in the lower cervical spine. Our hypotheses were that it is the contraction of the muscles, ligaments, and capsules of atlantoaxial joint that prevent reduction, and that most of IAADs might be reduced by anterior atlantoaxial joint release without the odontoid resection, and that further reduction and stabilization might be achieved by special posterior fixation. METHODS: A consecutive series of 33 patients with IAAD were surgically treated. Dislocation or reduction was assessed before surgery, immediately after surgery, and at the final fol5786-up. Etiology, instrumentation, levels fused, and complications were documented. All patients were assessed clinically for neurologic recovery by Odom's method. RESULTS: The mean age was 32 years (range, 7-63 years). The pathology included os odontoideum in 8 patients, occipitalization of C1 in 19 patients, malunion of odontoid fracture in 5, and relaxation of transverse ligament of atlas in 1. Twenty five patients presented neurologic signs and symptoms. Anterior release was performed without odontoid resection in all cases. Four patients underwent transarticular C1-C2 screw fixation, 3 had C1-C2 pedicle screw and plate fixation, and 26 required occipitocervical fixation. Twenty-five cases resulted in an anatomic reduction, 8 had partial reduction. Complication included one dysphagia and two nasal phonations. The mean follow-up period was 33.7 months (range, 24-55 months). There was no pseudarthrosis, and all but 1 of the patients with neurologic deficit showed improvement. CONCLUSION: This series has demonstrated the safety and efficacy of the transoral anterior atlantoaxial release in the reduction of IAAD. Most of the so-called irreducible/fixed AAD could become reducible after anterior release without odontoid resection. The posterior short-segment atlantoaxial or occipitocervical fixation, especially the plate screw instrumentation, could achieve further reduction and provide immediate stabilization. One-stage anterior release and posterior instrumentation and fusion are a safe and reliable operation in experienced hands.

[Reliability of direct probing isthmus of axial vertebrae to defining the screw path in atlas during Magerl technique].

OBJECTIVE: To evaluate the accuracy and reliability of atlantoaxial transarticular screw insertion (Magerl's technique) in atlas under lateral fluoroscopic monitoring without anteroposterior view. METHOD: Seventy-five consecutive patients with atlantoaxial instability, 48 males and 27 females, aged 35.1, were treated by Magerl's technique. The screw path in atlas was achieved by direct probing the isthmus of axial vertebrae then identifying its position through the atlantoaxial joint correlation. Postoperative transoral X ray and CT film were used for analysis of the position of the 150 screws in the mass of atlas. Three areas were delimitated in and around the lateral mass of atlas: area A (inside the joint face), area: B (outside the joint face but still in lateral mass), and area C area (outside the lateral mass) so as to analyze the location of screws. RESULTS: Among the 150 screws 139 (92.7%) were located in area A, 8 in area B(1) and 3 in area B(2) (7.3%), and none in area C. All cases got atlantoaxial union 3 months after operation. CONCLUSION: The method of "direct probing" is reliable for identifying the path of screw in atlas.

[Clinical characteristics and treatment of flexion-distraction stage I injuries in subaxial cervical spine].

OBJECTIVE: To study the clinical characteristics and treatment of flexion-distraction stage I injuries in subaxial cervical spine. METHODS: Twelve cases of flexion-distraction stage I injuries with delayed symptoms, admitted in our hospital between January 1995 and December 2004, were studied retrospectively. In acute phase, all of 12 cases had neck pain and limited neck movements, neurological deficits were found in 6 of 12 cases. Eight cases had a correct diagnosis, and 2 cases had a error diagnosis, 2 cases missed. All cases were satisfactory by the primary conservative treatment. After 274 days average asymptomatic intervals, all of 12 cases had recurrence of neck pain, delayed neurological deficits were found in 10. MRI showed that all of 12 cases were unstable injuries. RESULTS: All of the 12 patients were treated operatively. Decompression, fusion and fixation were performed by anterior approach in 9 cases, and by combined anterior and posterior approach in 3 cases. The average follow-up period was 33.1 months. Neck pain had great recovery in all cases, 10 cases with neurological deficits, 7 returned normal. Radiographic evidences of intervertebral bony fusion and good cervical alignment were observed in all of 12 cases. CONCLUSIONS: Flexion-distraction stage I injuries is often caused by ligament and disc injuries, and often missed with subtle symptoms and radiographic changes. Inadequate primary treatment options are often due to failure to recognize the instability, and maybe result in delayed injuries. MRI is helpful for the early accurate evaluation of spinal stability. Unstable injury require early surgical treatment. The anterior approach operation is recommended to most of these patients with acute and old injuries. Combined anterior and posterior approach operation should be considered in these patients who have old injuries with stiff kyphosis.

[X-ray measurement of cervical spinal canal in patients with degenerative lumbar spinal canal stenosis].

OBJECTIVE: To investigate the mechanism of high occurrence of cervical spondylotic myelopathy in the patients with degenerative lumbar spinal stenosis and the relationship between these two diseases. METHODS: Lateral radiographic plain films were made on 68 cases with degenerative lumbar spine stenosis 23 males and 45 females, aged 50.0 (22 - 69). The sagittal diameter of the spinal canal (a) was obtained by measuring the shortest distance between the middle point of the posterior margin of the cervical spinal body to the connective cortex of spinal process and vertebral lamina, the distance between the middle points of anterior and posterior margins of vertebral body was measured as the sagittal diameter of vertebral body (b), and the ratio of these sagittal diameters was calculated for the vertebral bones C3 - C7. The data of sagittal diameters of cervical spinal canal and cervical vertebral body and relevant a/b ratio value obtained from 411 healthy subjects ware used as normal controls to be compared with those of the degenerative lumbar spine stenosis patients. RESULTS: In the group of degenerative lumbar spinal stenosis the average value of a/b ratio of C3 - C7 were 0.781 in the males and was 0.807 in females respectively, both significantly lower than those of the healthy control group (0.874 in the males and 0.968 in the females respectively, both P < 0.05). The incidence rate of developmental cervical spinal stenosis in the group of degenerative lumbar spine stenosis was 27.9%, and that in healthy objective was 10%. CONCLUSION: Compared to the healthy objectives, the patients with degenerative lumbar spinal stenosis is easier to be inclined to the developmental cervical spinal stenosis.

Adeno-associated virus-mediated bone morphogenetic protein-7 gene transfer induces C2C12 cell differentiation into osteoblast lineage cells.

AIM: To investigate the effects of bone morphogenetic protein-7 (BMP7)-expressing recombinant adeno-associated virus (AAV) vector on the differentiation of C2C12 cells. METHODS: AAV-BMP7 was packaged by infecting the stable cell clone BHK-21 (integrated with recombinant AAV vector plasmid pSNAV-BMP7) with recombinant herpes simplex virus type 1, which expresses AAV-2 Rep and Cap and possesses AAV packaging functions. Following infection with AAV-BMP7 at multiplicities of infection of 1 x 10(5) vector genomes per cell and subsequent culture, C2C12 cells were assessed qualitatively for BMP7 production, alkaline phosphatase activity, osteocalcin production and Cbfal and MyoD expression. RESULTS: C2C12 cells transduced with AAV-BMP7 could produce BMP7 protein until d 28. Alkaline phosphatase in the cultured C2C12 cell lysate was elevated. Secreted osteocalcin in the culture medium was detectable at d 12 and Cbfal mRNA expression level was upregulated, coinciding with downregulation of MyoD in a temporal manner. CONCLUSION: The present in vitro study demonstrated that AAV-BMP7 could infect and efficiently convert C2C12 cells from myoblasts into osteoblast lineage cells.