Synthesis of pyrazino[1,2-b]indazoles via cascade cyclization of indazole aldehydes with propargylic amines.

An efficient intermolecular annulation of indazole aldehydes with propargylic amines has been developed for the synthesis of pyrazinoindazoles under catalyst- and additive-free conditions. This straightforward methodology was found to feature a wide substrate scope, high atom economy and environmental advantages. The bioactivity results of these new pyrazino[1,2-b]indazoles showed that some of them exhibited significant antifungal activity.

Treatment of irreducible atlantoaxial dislocation using the transoral atlantoaxial pedicle screw technique. A report of 10 cases.

OBJECTIVE: The purpose of this work is to evaluate the outcome of the transoral atlantoaxial pedicle screw technique for the treatment of irreducible atlantoaxial dislocation (IAAD). PATIENTS AND METHODS: A total of 10 patients with IAAD were treated using the transoral atlantoaxial pedicle screw technique. We compared preoperative and postoperative JOA (Japanese Orthopedic Association) scores and observed bone graft fusion rate of the atlantoaxial joint, and examined whether our technique was suitable for the treatment of IAAD. RESULTS: The mean preoperative and postoperative JOA scores (9.2 ± 0.63 and 12.9 ± 0.73, respectively) were significantly different (P < 0.05). The atlantoaxial rigid bony fusion rate was 100 % in 10 cases. All cases were followed up for an average of 5.1 years (range 3.5-6 years). CONCLUSION: The transoral atlantoaxial screw reconstruction plate technique is a novel surgical technique for the treatment of IAAD in upper cervical diseases.

Anterior pedicle screw fixation of C2: an anatomic analysis of axis morphology and simulated surgical fixation.

STUDY DESIGN: Human cadaveric study measuring the morphology of C2 vertebra, description of anterior placement of pedicle screw with post-fixation computed tomography (CT) analysis. OBJECTIVE: To assess the potential feasibility and safety anterior placement of C2 pedicle screws. SUMMARY OF BACKGROUND DATA: Posterior pedicle screw fixation has become an established technique for upper cervical reconstruction. To our knowledge few reports in the previous literature have described the placement of or anatomy related to anteriorly approach C2 pedicle screws. METHODS: The morphology of 60 human C2 vertebrae was measured directly to assess the size, position, and relative approach angle of the pedicles from an anterior perspective. In an additional 20 cadaveric cervical spines, bilateral 3.5 mm titanium C2 pedicle screws were placed and analyzed for pedicle morphology and placement accuracy with thin cut, 1 mm axial CT. RESULTS: The mean C2 pedicle width measured directly and by CT scan was 7.8 and 6.6 mm, and the average length of the right and left pedicle was 26.4 and 25 mm, respectively. The mean transverse angle (α) was 17.6° and 21.4°, whereas declination angle (ß) anterior to posterior was 13.8° and 10.6°, respectively. CONCLUSIONS: Quantitative data regarding C2 pedicle shape and location with respect to the anterior placement of pedicle screws have not been previously reported. This study indicates that anterior placement of 3.5 mm C2 pedicle screws through a transoral approach may be both feasible and safe and also provides an important anatomic analysis that may guide clinical application.

Clinical application of computer-aided design-rapid prototyping in C1-C2 operation techniques for complex atlantoaxial instability.

STUDY DESIGN: This is a retrospective clinical study. OBJECTIVE: To evaluate the clinical efficacy of computer-aided design-rapid prototyping (CAD-RP) techniques in surgical treatments for atlantoaxial instability (AAI). SUMMARY OF BACKGROUND DATA: The complexity of the upper cervical anatomic structures makes the procedures for the treatment of AAI particularly challenging for surgeons. The present study represents a series of C1-C2 surgery for AAI aided by CAD-RP. METHODS: A total of 49 patients (21 men and 28 women) with AAI were treated in our department. According to the use of the CAD-RP technique, the patients were divided into RP group and No RP group. Preoperative CT scans of the upper cervical spine were performed for each patient. For the RP group, physical RP models of the upper cervical spine were manufactured from the 3-dimensional CT data and were used for intraoperative guidance. Personalized surgeries were performed for each case of the 2 groups. The screw malposition rate, frequency of using intraoperative fluoroscopy, operation time, blood loss, and improvement of neurological function were compared between the 2 groups. The mean follow-up duration was 32 months (range, 24-50 mo). RESULTS: The operations were successfully performed in 48 cases expect for 1 case in the No RP group. A total of 204 screws were placed. The intraoperative fluoroscopy frequency and operation time were significantly lower in the RP group than that in the No RP group in both posterior and anterior approaches, whereas the screw malposition rate showed no difference between the 2 groups for both approaches. After the operation, 48 cases achieved satisfactory decompression of the cervical cord and repositioning of the atlantoaxial spine. During follow-up, 47 cases presented improvements in the spinal nerve function within 2 years. CONCLUSIONS: CAD-RP techniques have significant benefits for surgeons providing personalized treatments for AAI, especially cases with complicated deformities.

Personalised modified osteotomy using computer-aided design-rapid prototyping to correct thoracic deformities.

The correction of severe thoracic deformities is challenging. However, the usual imaging modalities are not sufficient for performing the surgery. Our objective was to describe the procedure and results of posterior modified wedge osteotomy aided by the techniques of computer-aided design-rapid prototyping (CAD-RP) to correct thoracic deformities. Twenty-one patients with thoracic deformities (eight males; 13 females) formed the study group. All patients underwent computed tomography (CT) scanning and CAD-RP, and a model of thoracic deformities and navigation templates of pedicles were created for each patient and used to analyse the spinal deformities and serve as anatomical reference. Aided by these models, personalised modified wedge osteotomy combining the eggshell technique and posterior vertebral column resection was performed. Using CAD-RP improved the safety and accuracy of surgery and screw placement in the 21 patients in whom 41 vertebrae were removed and 216 pedicle screws were placed. The average operation time was 260 (200-420) min, with an average blood loss of 1,900 ml (range 800-3560 ml). The percentage of deformity correction was 56.3% (from 72.1° to 31.5°) in the coronal plane and 60.4% (from 81.6° to 32.3°) in the sagittal plane. No patient had serious complications or implant failure. Personalised single-stage posterior modified wedge osteotomy is an effective procedure for treating thoracic deformities. Using CAD-RP and the RP models have significant benefits for personalised surgical treatment of complex thoracic deformities.

[Risk factors for postoperative pulmonary complications following transoral operation for the atlanta-axis disorders].

OBJECTIVE: to evaluate the risk factors for postoperative pulmonary complications following transoral operation for the atlanta-axis disorders. METHODS: total 104 cases were collected from January 2005 to June 2009. Twelve variables among patients with PPCs and without PPCs were analyzed by logistic regression analysis. RESULTS: the incidence of postoperative pulmonary complications following transoral operation for the atlanta-axis disorders was 22.1% (23/104). There was significantly difference in 9 variables between patients with PPCs and without PPCs, and 5 variables as serum albumin < 35 g/L (OR = 15.185, P = 0.003), tracheotomy (OR = 32.254, P = 0.015), Frankle grade (OR = 8.866, P = 0.001), the duration of intubation > 4 d (OR = 7.934, P = 0.002), the duration of surgery > 6 h (OR = 16.889, P = 0.006) were found to be significantly related to the development to postoperative pulmonary complications by multivariate analysis. CONCLUSION: serum albumin < 35 g/L, tracheotomy, Frankle grade, the duration of intubation > 4 d, the duration of surgery > 6 h are the risk factors for postoperative pulmonary complications following transoral operation for the atlanta-axis disorders.

[Diagnosis and treatment for complicated atlantoaxial dislocation].

OBJECTIVE: To explore the clinical characteristics and treatment methods for complicated atlantoaxial dislocation. METHODS: A retrospective evaluation was done to summarize and analyze the clinical characteristics and complicated factors of 54 patients with complicated atlantoaxial dislocation who could not to be treated effectively by using conventional therapy in our hospital from February 2005 to October 2008. According to different complicated factors, different treatment methods mainly including transoral atlantoaxial reduction plate-III (TARP-III) operation, decompression procedure with deep grinding guided by computer aided design-rapid prototyping (CAD-RP), screw placement technique with CAD-RP guide plate and extensile approach surgery were performed. RESULTS: The average follow-up period was 24 months. Among 54 cases, 48 cases achieved immediate anatomic reduction completely and 6 cases almost achieved anatomical reduction. All the compressed spinal cords were decompressed sufficiently. The decompression rate was 86.0% and the improvement rate of nerve function was 77.8%. Two cases suffered postoperative intracranial infection. CONCLUSION: Some cases of complicated atlantoaxial dislocation can be effectively treated by using TARP-III operation, decompression procedure with deep grinding guided by CAD-RP, individualized screw placement technique with CAD-RP guide plate and extensile approach surgery.

Synthesis and anti-gastric cancer activity evaluation of novel triazole nucleobase analogues containing steroidal/coumarin/quinoline moieties.

A series of novel triazole nucleobase analogues containing steroidal/coumarin/quinoline moieties have been synthesized based on copper-catalyzed azide-alkyne cycloaddition (CuAAC). The anti-cancer activity of the new triazole nucleobase analogues was studied in gastric cancer cell lines (MGC-803, SGC-7901) and normal gastric epithelial cells (GES-1) in vitro. Some of the synthesized compounds could significantly inhibit the proliferation of these tested cancer cells. Among the tested compounds, compound 20c demonstrated good anti-proliferation activity against MGC-803 cells (IC50 = 1.48 µM) and SGC-7901 (IC50 = 2.28 µM) cells as well as the best selectivity between the cancer and normal cells. Further mechanistic studies indicated that compound 20c could down-regulate the expression of TGF ß1 both in the tested gastric cancer cell lines and inhibit the cell migration and invasion. The results of the study indicate that compound 20c could be used as a promising skeleton for anti-gastric cancer agents with improved efficacy and less side effects.

Three-Dimensional-Printed Individualized Guiding Templates for Surgical Correction of Severe Kyphoscoliosis Secondary to Ankylosing Spondylitis: Outcomes of 9 Cases.

OBJECTIVE: To report the outcomes of severe kyphoscoliosis secondary to ankylosing spondylitis (AS) corrected with 3D-printed individualized guiding templates. METHODS: Computed tomography (CT) data of patients with severe kyphoscoliosis secondary to AS were used to reconstruct 3D models of the spine and to develop a surgical plan. An asymmetric wedge pedicle subtraction osteotomy (PSO) was simulated using medical computer design software. Before the actual surgery, continual surgical simulations were performed until the most suitable one was obtained, and personalized guiding templates were manufactured for the anticipated PSO. During operation, the osteotomy plane and trajectories for the pedicle screws were positioned by the designed patient-specific 3D-printed guiding templates. RESULTS: In this study, we reviewed 9 patients who underwent correction of kyphoscoliosis using a 3D-printed individualized guiding template and were followed for a median of 21.4 months (range, 9-36 months). The average correction at the site of osteotomy was 65.9°. No patient experienced severe complications, such as misplaced pedicle screws or neurologic complications. At the last follow-up, no patient exhibited implant dysfunction on radiography. CONCLUSIONS: Preoperative surgical simulation using 3D-printed templates is a viable technique that enables surgery to meet both patient- and surgeon-specific requirements for correction of severe thoracolumbar kyphoscoliosis. These 3D-printed templates can guide the performance of planned PSO to provide functional restoration of severe kyphoscoliosis secondary to AS.

Design, synthesis and biological evaluation of new steroidal ß-triazoly enones as potent antiproliferative agents.

ß-Triazoly enones are biologically interesting scaffolds, incorporation of such scaffolds into the steroid nucleus may generate new bioactive steroids and further enrich structural types of steroids. In this work, a series of new steroidal ß-triazoly enones were synthesized based on click chemistry and Claisen-Schmidt condensation reaction and further evaluated for their antiproliferative activity against a panel of cancer cells. Most of these compounds showed better potency against PC-3 and MGC-803 cells. Particularly, compound 5a inhibited PC-3 and MGC-803 cells potently with the IC50 values of 1.61 and 1.16 µM, respectively, and was less toxic toward GES-1 with an IC50 value of 20.72 µM. Further mechanistic studies showed that compound 5a inhibited migration and invasion of MGC-803 and PC-3 dose-dependently. Treatment with compound 5a varied mRNA levels and protein expression of EMT markers in both cells. Collectively, the steroidal ß-triazoly enones could be potentially utilized to develop new anticancer agents with the ability of inhibiting cell migration and invasion.

Development of quantitative real-time polymerase chain reaction for the detection of Vibrio vulnificus based on hemolysin (vvhA) coding system.

OBJECTIVE: To establish a TaqMan real-time fluorescent quantitative PCR to detect Vibrio vulnificus based on the hemolysin gene (vvhA) coding cytolysin. METHODS: Primers and probes in the conserved region of the vvhA gene sequence were designed for the TaqMan real-time PCR to detect 100 bp amplicon from V. vulnificus DNA. Recombinant plasmid pMD19-vvhA100 was constructed and used as a positive control during the detection. Minimal amplification cycles (Ct value) and fluorescence intensity enhancement (DeltaRn value) were used as observing indexes to optimize the reaction conditions of TaqMan real-time PCR. The TaqMan assay for the detection of Vbirio vulnificus was evaluated in pure culture, mice tissue which artificially contaminated Vibrio vulnificus and clinical samples. RESULTS: The established TaqMan real-time PCR showed positive results only for Vibrio vulnificus DNA and pMD19-vvhA100. The standard curve was plotted and the minimum level of the vvhA target from the recombinant plasmid DNA was 10(3) copies with a Ct value of 37.94+/-0.19, as the equivalent of 0.01 ng purified genomic DNA of Vibrio vulnificus. The results detected by TaqMan PCR were positive for the 16 clinical samples and all the specimens of peripheral blood and subcutaneous tissue of mice which were infected with Vibrio vulnificus. CONCLUSION: TaqMan real-time PCR is a rapid, effective, and quantitative tool to detect Vibro vulnificus, and can be used in clinical laboratory diagnosis of septicemia and wound infection caused by Vibrio vulnificus.

[Case-control study of therapeutic effects between extreme lateral interbody fusion and conventional posterior operation for the treatment of upper lumbar disc herniation].

OBJECTIVE: To evaluate the clinical outcomes between extreme lateral interbody fusion and conventional posterior operation in the treatment of upper lumbar disc herniation. METHODS: Among 60 patients with upper lumbar disc herniation were treated with extreme lateral interbody fusion(XLIF) or conventional posterior operation from June 2010 to December 2014, 30 patients(19 males and 11 females) were treated with XLIF (XLIF group); and the other 30 patients(17 males and 13 females) were treated with conventional posterior operation (conventional group). In XLIF group, the lesions occurred at T12L1 segments in 2 patients, at L1,2 segments in 6 patients, at L2,3 segments in 10 patients, and at L3,4 segment in 12 patients. In conventional group, the lesions occurred at T12L1 segments in 1 patient, at L1,2 segments in 6 patients, at L2,3 segments in 8 patients, and at L3,4 segment in 15 patients. Operative incision lengths, time, blood loss, postoperative draining volume, hospital stays were recorded. Pre-and post-operative visual analogue score(VAS) and Japanese Orthopedic Association(JOA) were compared between two groups. According to the image data, the intervertebral fusion device was observed to be displaced and the rate of interbody fusion was analyzed. RESULTS: All the patients were followed up, and the duration ranged from 12 to 48 months, with an average of 29 months. The complications included 2 femoral nerve damage in XLIF group (postoperative recovery within 3 months) and superficial incision infection in conventional group(cured by anti-infection). There were no patients with cerebrospinal fluid leakage(CSFL), cauda equina injuries or functional deterioration in the nerve root of lower limbs. In the XLIF group: the operative time was (65.6±20.5) minutes, blood loss was (48.8±15.3) ml, postoperative draining volume was 0 ml. In the conventional group: the operative time was (135.2±33.9) minutes, blood loss was (260.3±125.7) ml, postoperative draining volume was (207.1±50.2) ml. The operative time, blood loss, postoperative draining volume in XLIF group were less than those in the conventional group(P<0.05). The JOA and VAS score were significantly improved in both groups during the follow-up period compared with those before operation(P<0.05). But the difference of the JOA and VAS score between the two groups 1, 6, and 24 months after surgery had not significant differences(P>0.05). There were no significant differences in the fusion rate between the two groups 6 and 12 months after operation(P>0.05). CONCLUSIONS: The XLIF fusion for the treatment of upper lumbar disc herniation has several advantages such as minimal invasive, stable vertebral plate, less complications and postoperative fusion rate, which has a better clinical effect.

Expert consensus for PVCR in severe, rigid and angular spinal deformity treatment: The Kunming consensus.

In the past decades, an increasing number of surgeons started using posterior vertebral column resection (PVCR) to treat severe, rigid and angular spinal deformities. Little high-level evidence is available to guide surgical treatment. The aims of our study were to identify important surgical strategies and key technical points of Chinese experts who have extensive experience in the management of severe, rigid and angular spinal deformities using PVCR, and to standardize and unify the current core concepts. Workgroups of consensus were formed by selecting nationwide representing experts and comprehensive consultations. Eight task forces for major issues were established, then retrieval of literature, collection of expert opinions and writing of review articles were carried out. A modified Delphi process was chosen in round-table forum with three face-to-face meetings. Consensus was reached with items graded more than seven points including: indications and contraindications of PVCR; review PVCR in the evolution of spinal osteotomies; The corrective mechanism and safety of spinal cord; monitoring and responses of spinal cord crisis; characteristics and therapeutic outcome of pulmonary function; management of bleeding during PVCR; relationship of pedicle screw insertion and spinal cord safety; and analysis of non-neurologic complications and prevention strategies. In conclusion, The essential properties regarding PVCR procedure are tightly linked with various factors such as medical and surgical indication, range and level of vertebral column resection, strategies of correction, corrective efficiency and control of neurological risk. PVCR is used mainly for severe, rigid spinal deformity that is not manageable by other osteotomy techniques.

The anatomical study of transoral atlantoaxial reduction plate internal fixation.

OBJECTIVE: To study relevant anatomical features of the structures involved in transoral atlanto-axial reduction plate (TARP) internal fixation through transoral approach for treating irreducible atlanto-axial dislocation and providing anatomical basis for the clinical application of TARP. METHODS: Ten fresh craniocervical specimens were microsurgically dissected layer by layer through transoral approach. The stratification of the posterior pharyngeal wall, the course of the vertebral artery, anatomical relationships of the adjacent structures of the atlas and axis, and the closely relevant anatomical parameters for TARP internal fixation were measured. RESULTS: The posterior pharyngeal wall consisted of two layers and two interspaces: the mucosa, prevertebral fascia, retropharyngeal space, and prevertebral space. The range from the anterior edge of the foramen magnum to C(3) could be exposed by this approach. The thickness of the posterior pharyngeal wall was (3.6+/-0.3) mm (ranging 2.9-4.3 mm) at the anterior tubercle of C1, (6.1+/-0.4) mm (ranging 5.2-7.1 mm) at the lateral mass of C(1) and (5.5+/-0.4) mm (ranging 4.3-6.5 mm) at the central part of C(2), respectively. The distance from the incisor tooth to the anterior tubercle of C(1), C(1) screw entry point, and C(2)screw entry point was (82.5+/-7.8) mm (ranging 71.4-96.2 mm), (90.1+/-3.8) mm (ranging 82.2-96.3 mm), and (89.0+/-4.1) mm (ranging 81.3-95.3 mm), respectively. The distance between the vertebral artery at the atlas and the midline was (25.2+/- 2.3) mm (ranging 20.4-29.7 mm) and that between the vertebral artery at the axis and the midline was (18.4+/- 2.6) mm (ranging 13.1-23.0 mm). The allowed width of the atlas and axis for exposure was (39.4+/-2.2) mm (ranging 36.2-42.7 mm) and (39.0+/-2.1) mm (ranging 35.8-42.3 mm), respectively. The distance (a) between the two atlas screw insertion points (center of anterior aspect of C(1) lateral mass) was (31.4+/-3.3) mm (ranging 25.4-36.6 mm). The vertical distance (b) between the line connecting the two C(1) screw entry points and that connecting the two C(2) screw entry points (at the central part of the vertebrae, namely 3-4 mm lateral to the midline of C(2) vertebrae) was (21.3+/-2.7) mm (ranging 19.4-24.3 mm), with an a/b ratio of 1.3-1.5. The screws of TARP had a lateral tilt of 12.2 degrees+/-0.4 degrees(ranging 10.2 degrees-14.6 degrees) at C(1) and a medial tilt of 7.3 degrees+/-0.3 degrees (ranging 5.1 degrees-9.4 degrees) at C(2) relative to the coronal plane. CONCLUSIONS: An atlanto-axial surgery through transoral approach is safe and feasible. This approach is suitable for an anterior TARP internal fixation, and the design of the internal fixation system should be based on the above anatomical data.

Transoral atlantoaxial reduction plate fixation for irreducible atlantoaxial dislocation.

OBJECTIVE: To design a clinically applicable transoralpharyngeal atlantoaxial reduction plate (TARP), introduce the operation procedure, and evaluate its preliminary clinical effects. METHODS: A novel TARP system, including butterfly titanium alloy plate, self-locking screws, atlantoaxial reductor and other operational instruments was developed. This system was applied clinically on five patients with irreducible atlantoaxial dislocation of congenital or traumatic origin. During operation, the reduction was completed by the combined action of the plate and the atlantoaxial reductor after transoral joint release and cord decompression. Bone graft granules were implanted between the bilateral atlantoaxial joints and TARP was used to immobilize subsequently the atlas and axis. RESULTS: Clinical application demonstrated that TARP could induce instant reduction and that the method was operationally feasible and its postoperational effect was satisfactory. CONCLUSIONS: The design of TARP is novel. The operational procedure is simple and easy to use. Furthermore, instant reduction can be completed during the operation and the fixation is relatively stable. TARP is an ideal alternative for irreducible atlantoaxial dislocation and may have excellent prospects for further clinical applications.

[Anatomic evaluation the entry point of C2 pedicle screw].

OBJECTIVE: To study the relevant position of C(2) pedicle to C(2) inferior articular process, set up a technique of C(2) pedicle screw placement with the inferior articular process of axis as an anatomic landmark. METHODS: Fifty C(2) bone specimens were used to measure the distance from the sagittal midline to the medial border, the midpoint and the lateral border of C(2) inferior articular process or C(2) pedicle; the width and the height of the C(2) pedicle were also evaluated. The anatomic relation between the measurements data of C(2) pedicle and that of C(2) inferior articular process were analyzed, and the technique of C(2) pedicle screw fixation was established. RESULTS: The medial border of C(2) inferior articular process was averaged (3.67 +/- 0.41) mm lateral to that of C(2) pedicle, and the midpoint C(2) inferior articular process was averaged (1.15 +/- 0.44) mm lateral to the lateral border of C(2) pedicle, respectively. Using the C(2) inferior articular process as landmark, two techniques was established for C(2) pedicle screw placement. The entry point of method A was located in 2 mm medial and superior to the central point of C(2) inferior articular process; the entry point of method B was at the crossing point of the medial border C(2) inferior articular process with the superior quarter of C(2) inferior articular process. CONCLUSIONS: There is a steady anatomic relation between C(2) pedicle and C(2) inferior articular process, the C(2) inferior articular process could be as a convenient key anatomic landmark to determine the location of C(2) pedicle and the position of C(2) pedicle screw entry point.

An 11-Year Review of the TARP Procedure in the Treatment of Atlantoaxial Dislocation.

STUDY DESIGN: Retrospective study. OBJECTIVE: The aim of the study was to introduce the surgical techniques and evaluate the clinical outcomes of transoral atlantoaxial reduction plate (TARP) for the treatment of atlantoaxial dislocation. SUMMARY OF BACKGROUND DATA: Researchers have reported on transoral plate internal fixation for the treatment of irreducible atlantoaxial dislocation (IAAD) without long-term follow-up and detailed clinical experience. METHODS: The clinical records of 388 patients with atlantoaxial dislocation (IAAD, 340 cases; fixed atlantoaxial dislocation [FAAD], 48 cases) who received the TARP procedure from April 2003 to September 2014 were retrospectively reviewed. They were treated separately with TARP-I or TARP-II (82 cases), TARP-III (248 cases), or TARP-IV (58 cases). X-ray and magnetic resonance imaging were used to evaluate the efficacy of reduction and the degree of decompression, respectively. The long-term clinical outcome was evaluated by Japanese Orthopaedic Association scoring and the Symon and Lavender standard. RESULTS: Immediate reduction was achieved for all the patients with IAAD (340/340), whereas anatomical reduction was achieved for 98.2% of patients (334/340). Anatomical reduction was achieved in 87.5% of patients with FAAD (42/48). The average degree of spinal cord decompression ranged from 75% to 100% with an average of 88.4%. The clinical data of 106 patients were evaluated in the latest follow-up (12-108 mo, average 60.5 mo). The average spinal cord improvement rate by Japanese Orthopaedic Association scoring was 62.1%. According to the Symon and Lavender standard, there were 85 cases rated as markedly effective, 104 cases as effective, and 2 cases as noneffective. The overall markedly effective rate was 80% and the effective rate was 98%. CONCLUSION: The TARP procedure showed good anterior atlantoaxial release, reduction, decompression, and internal fixation for patients with IAAD and FAAD through a single anterior approach. It has the advantages of three-dimensional immediate atlantoaxial reduction and sufficient decompression. LEVEL OF EVIDENCE: 3.

[Anatomic identification of the location of the pedicle of atlas with the lateral mass of C2 to C4 as the landmark].

OBJECTIVE: To study the relevant position of the pedicle of C1 to the lateral mass of C(2-4), set up an identification technique for the entry point decision of C1 pedicle screw by using the lateral mass of C(2-4) as anatomic landmarks. METHODS: Twenty cadaver specimens were used to measure the distance from the sagittal midline of spine to the medial border, the midpoint and the lateral border of C1 pedicle or the lateral mass of C2, C3 or C4. The anatomic relation between the measurements data of C1 pedicle and that of the lateral masses of the cervical vertebrae were analyzed, and the technique of C1 pedicle screw fixation was established. RESULTS: The average medial border of the lateral mass of C2, C3 and C4 was 0.37 mm, 0.27 mm and 0.24 mm lateral to that of C1 pedicle, the average midpoint of the lateral mass of C2, C3 and C4 was 1.18 mm, 1.41 mm and 1.74 mm lateral to that of C1 pedicle, and the average lateral border of the lateral mass of C2, C3 and C4 was 1.96 mm, 2.54 mm and 3.24 mm lateral to that of C1 pedicle, respectively. CONCLUSION: There is a steady anatomic location relation between C1 pedicle and the lateral mass of C2, C3 or C4. As well as the lateral mass of C2, the lateral mass of C3 or that of C4 could be convenient anatomic landmarks to determine the location of C1 pedicle and the position of C1 pedicle screw entry point.

[Surgical anatomy of transoral atlantoaxial reduction plate internal fixation].

OBJECTIVE: To provide anatomical data for transoral atlantoaxial reduction plate internal fixation. METHOD: Microsurgical dissecting was performed on 10 fresh craniocervical specimens layer by layer according to transoral approach. Stratification of posterior pharyngeal wall, course of vertebral artery, adjacent relationships of atlas and axis and correlative anatomical parameters of internal fixation to atlantoaxial joint were observed. RESULT: (1) Posterior pharyngeal wall consisted of 2 layers and 2 interspace: mucosa, anterior fascia of vertebrae, posterior interspace of pharynx and anterior interspace of vertebrae. (2) The range from anterior rim of foramen magnum to C3 could be exposed by this approach. (3) The distance between the vertebral artery at atlas and midline was (25.2 +/- 2.3) mm and that between the vertebral artery at axis and midline was (18.4 +/- 2.6) mm. (4) The width of atlas and that of axis could be exposed respectively to (39.4 +/- 2.2) mm and (39.0 +/- 2.1) mm. The distance (a) between 2 atlas screw inserting points (center of anterior aspect of C-1 lateral mass) was (31.4 +/- 3.3) mm. The vertical distance (b) between the connecting line of 2 atlas screw inserting points and that of 2 axis screw inserting points (at the central part of the vertebrae which was 3 - 4 mm lateral to the midline of C-2 vertebrae) was (18.7 +/- 2.7) mm. The odds of a/b was 1.5 approximately 1.7. CONCLUSIONS: Anterior atlantoaxial plate internal fixation through transoral approach is suitable and feasible. The design of the plate should be based on the above data.