The development of posterior reduction forceps for atlantoaxial dislocation and its preliminary application in irreducible atlantoaxial dislocation.

OBJECTIVE: To develop posterior reduction forceps for atlantoaxial dislocation and evaluate the preliminary clinical application of this forceps in assisting simple posterior screw-rod system reduction and fixation in the treatment of irreducible atlantoaxial dislocation. METHODS: Based on the posterior atlantoaxial screw-rod system, posterior reduction forceps was developed to assist simple posterior screw-rod system for the treatment of irreducible atlantoaxial dislocation. From January 2021 to October 2022, 10 cases with irreducible atlantoaxial dislocation were treated with this technique. The Japanese Orthopaedic Association (JOA) score was applied before and after surgery to evaluate the neurological status of the patient, and the Atlanto-dental interval (ADI) was measured before and after surgery to evaluate the atlantoaxial reduction. X-ray and CT were performed to evaluate internal fixation, atlantoaxial sequence and bone graft fusion during regular follow-up. MRI was performed to evaluate the status of atlantoaxial reduction and spinal cord compression after surgery. RESULTS: All 10 patients were successfully operated, and there were no complications such as spinal nerve and vascular injury. Postoperative clinical symptoms were significantly relieved in all patients, and postoperative JOA score and ADI were significantly improved compared with those before surgery (P < 0.05). CONCLUSIONS: The developed posterior reduction forceps for atlantoaxial dislocation can assist the simple posterior screw-rod system in the treatment of irreducible atlantoaxial dislocation to avoid the release in anterior or posterior approach and reduce the difficulty of surgery. The preliminary results of this technique are satisfactory and it has a good application prospect.

A comprehensive analysis and literature review of vertebral artery variation in craniovertebral junction using three-dimensional computed tomography angiography.

PURPOSE: To describe vertebral artery (VA) variation in patients with or without osseous anomalies at congenital craniovertebral junction (CVJ). METHODS: In the present study, we retrospectively analyzed 258 patients with VA variation who underwent three-dimensional computed tomography angiography (3D CTA) in our hospital from March 2017 to October 2019. RESULTS: Among 258 patients, 180 were accompanied by skeleton structural malformation, including 105 cases of occipital ossification of the atlas, 8 cases of the bipartite atlas, 7 cases of hypoplasia of the posterior arch of the atlas, 45 cases of C2/3 congenital fusion, 2 cases of C2/3/4 congenital fusion, and 13 cases of congenital os odontoid. VA variation was divided into type A (VA variation in the CVJ area without osseous anomalies) and type B (VA variation in the CVJ area with osseous anomalies). There are totally 10 subtypes, including type A1 (atlas occipitalization with VA entrance approach close to middle line, 20.2%); type A2 (atlas occipitalization with VA entrance approach far from middle line, 30.2%); type A3 (first intersegmental VA in C1-C2, 1.9%); type A4 (fenestration of the VA, 2.3%); type A5 (VA bulging type, 6.6%); type A6 (VA exposures with the absence of the posterior atlas arch, 2.3%); type A7 (C2 inner wall type, 0.4%); type A8 (single vertebral artery, 2.3%); type B1 (posterior ponticuli, 2.7%); and type B2 (high-riding VA, 31.4%). CONCLUSION: This study is expected to take the lead in the most comprehensive classification of VA variation.

Calcium phosphate cement promotes the stability of osteoporotic lumbar pedicle screw by enhancer-injecters with different number of holes.

BACKGROUNDS: This study aimed to compare whether Calcium phosphate cement (CPC) promotes the stability of osteoporotic lumbar pedicle screw by enhancer-injecters with different number of holes. METHODS: Through a self-designed bone cement injection device, the pedicle screw canal was strengthened with calcium phosphate bone cement, and divided into 4-hole group, 6-hole group, 8-hole group, straight pore group and the control group. The screw was inserted into the mechanical test module, the Maximum insertion torque and Maximum axial pull-out strength were recorded, and the distribution of calcium phosphate bone cement was analyzed by CT and X-ray. The data results were analyzed using SPSS19.0 statistical software package. RESULTS: The distribution of bone cement in different reinforcement groups was different and showed regularity. The bone cement in the 4-hole group was roughly located in the head 1/3 of the screw, the 6-hole group was located in the middle 1/3 of the screw, and the 8-hole group was located in the caudal 1/3 of the screw. Compared with the control group, the maximum axial pull-out force of screws in the lateral hole and full screw tunnel reinforcement group was significantly increased. There was no significant difference between the 4-hole, 6-hole and straight pore groups. There was no difference in the screw-in torque between the reinforcement groups, and they all increased significantly compared with the control group, and the difference was statistically significant. After the screw was pulled out, the interface between the bone cement and the polyurethane material was fractured, and a tight package was formed with the screw. CONCLUSIONS: Enhancer syringes with different hole numbers combined with CPC bone cement injection can significantly increase the maximum screw pull-out force. The 8-hole group has a smaller pull-out force and is relatively prone to leakage of reinforcing material, which lacks safety in use. The local reinforcement of 4-hole and 6-hole sheath can play a similar role to that of total nail tunnel reinforcement.

Treatment of irreducible atlantoaxial dislocation by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach.

OBJECTIVE: Investigate a novel method for treating irreducible atlantoaxial dislocation (IAAD) or with basilar invagination (BI) by bony deformity osteotomy, remodeling, releasing, and plate fixating through transoral approach. METHOD: From March 2015 to December 2019, 213 consecutive patients diagnosed as IAAD/BI were treated with transoral bony deformity remodeling and releasing combined with plate fixation. The main clinical symptoms include neck pain, headache, numbness of the limbs, weakness, unstable walking, inflexible hand-held objects, and sphincter dysfunction. The bony factors that impact reduction were divided into as follows: type A1 (sloping of upper facet joint in C2), type A2 (osteophyte in lateral mass joints between C1 and C2), type A3 (ball-and-socket deformity of lateral mass joint), type A4 (vertical interlocking between lateral mass joints of C1-C2), type A5 (regional bone fusion in lateral mass joints), type B1 (bony factor hindering reduction between the atlas-dens gap), type B2 (uncinate odontoid deformity), and type B3 (hypertrophic odontoid deformity). All of them were treated with bony deformity osteotomy, remodeling, and releasing techs. RESULT: The operation time was 144 [Formula: see text] 25 min with blood loss of 102 [Formula: see text] 35 ml. The average pre-operative ADI improved from 7.5 [Formula: see text] 3.2 mm pre-surgery to 2.5 [Formula: see text] 1.5 mm post-surgery (p < 0.05). The average VDI improved from 12.3 [Formula: see text] 4.8 mm pre-surgery to 3.3 [Formula: see text] 2.1 mm post-surgery (p < 0.05). The average pre-operative CMA improved from 115 [Formula: see text] 25° pre-surgery to 158 [Formula: see text] 21° post-surgery (p < 0.05); the pre-operative CAA changed from 101 [Formula: see text] 28° pre-surgery to 141 [Formula: see text] 10° post-surgery. After the operation, the clinic symptoms improved, and the JOA score improved from 9.3 [Formula: see text] 2.8 pre-operatively to 13.8 [Formula: see text] 2.5 in the sixth months of follow-up. CONCLUSION: In addition to soft tissue factors, bony obstruction was another important factor impeding atlantoaxial reduction. Transoral bony deformity osteotomy, remodeling, releasing combined with plate fixating was effective in treating IAAD/BI with bony obstruction factors.

Heat-Stimuli Shape Memory Effect of Poly (ε-Caprolactone)-Cellulose Acetate Composite Tubular Scaffolds.

Small-diameter artery disease is the most common clinical occurrence, necessitating the development of small-diameter artificial blood vessels. In this study, seven types of poly(-caprolactone)-cellulose acetate (PCL-CA) composite nanofiber membranes were prepared with different proportions of PCL and CA. The adhesion and growth of Mc3t3-e1 cells were considered to confirm the in vitro cytocompatibility of PCL-CA membranes. A smooth stainless-steel mandrel with a diameter of 4 mm was used to roll up the prepared nanofiber membranes to produce the tubular scaffold with 50 °C hot water. The tubular scaffolds were subjected to axial and circumferential tensile tests. The mechanical performance of the PCL-CA tubular scaffold could be improved by increasing the layers. In addition, the burst pressure (BP) of the tubular scaffolds was increased with the layers, and the BPs of six-layer (2380 ± 36.8 mmHg) and eight-layer (3720 ± 80.5 mmHg) tubular scaffolds were much higher than that of the human saphenous vein (2000 mmHg). The compression shape memory performances of the PCL-CA tubular scaffold with different layers were also investigated to simulate and analyze the contraction and expansion of tubular scaffolds. The experimental results showed that the compression strain of the tubular scaffold in the diameter direction reached 35%, and the ultimate shape recovery rate reached 87%. However, the shape fixity rate and shape recovery rate increased, demonstrating that the optimum number of layers can improve the compression shape memory performance of the tubular scaffold. The results of this study, including comprehensive morphological and mechanical properties and cytocompatibility, indicated the potential applicability of PCL-CA tubular scaffolds as tissue engineering grafts.

Smart Diffraction Gratings Based on the Shape Memory Effect.

The shape memory effect is the capability of a structure or a material that can be deformed into a certain temporary shape under external stimulus, and the shape will be fixed without the stimulus. The recovery process can be triggered by the same stimulus. The intelligent tunable device based on the shape memory effect has a wide range of applications in many fields. In the optical field, smart diffraction gratings can accomplish in situ optical diffractions according to requirements, meeting the high demand in the next generation of smart optical systems. However, it is essential to construct high-precision grating structures based on shape memory materials. Here, a smart diffraction grating based on UV-curable shape memory polymers (SMPs) via two-beam interference is reported, with nano-scale precision, excellent deformability and recovery ability, and adjustable spectroscopic performance. More importantly, based on the shape memory effect, grating structures that surpass the precision of the fabrication system can be obtained. The smart grating exhibits rapid deformation and recovery upon heating and long-term storage capability, which facilitates them to be applied in optics, electronics, and integrated sensing.

Conducting molybdenum sulfide/graphene oxide/polyvinyl alcohol nanocomposite hydrogel for repairing spinal cord injury.

A sort of composite hydrogel with good biocompatibility, suppleness, high conductivity, and anti-inflammatory activity based on polyvinyl alcohol (PVA) and molybdenum sulfide/graphene oxide (MoS2/GO) nanomaterial has been developed for spinal cord injury (SCI) restoration. The developed (MoS2/GO/PVA) hydrogel exhibits excellent mechanical properties, outstanding electronic conductivity, and inflammation attenuation activity. It can promote neural stem cells into neurons differentiation as well as inhibit the astrocytes development in vitro. In addition, the composite hydrogel shows a high anti-inflammatory effect. After implantation of the composite hydrogel in mice, it could activate the endogenous regeneration of the spinal cord and inhibit the activation of glial cells in the injured area, thus resulting in the recovery of locomotor function. Overall, our work provides a new sort of hydrogels for SCI reparation, which shows great promise for improving the dilemma in SCI therapy.

A novel bone cement injector augments Chinese osteoporotic lumbar pedicle screw channel: a biomechanical investigation.

BACKGROUND: The study aimed to (1) create a series of pedicle injectors with different number of holes on the sheath especially for the Chinese elderly patients and (2) further investigate the effects of the injectors on the augmentation of pedicle screw among osteoporotic lumbar pedicle channel. METHODS: This study used the biomechanical test module of polyurethane (Pacific Research Laboratory Corp, USA) to simulate the mechanical properties of human osteoporotic cancellous bone. The bone cement injectors were invented based on anatomical parameters of lumbar pedicle in Chinese elderly patients. Mechanical test experiments were performed on the bone cement injectors according to the three groups, namely, a local augmentation group, a full-length augmentation group, and a control group. The local augmentation group included three subgroups including 4-hole group, 6-hole group, and 8-hole group. All holes were laterally placed. The full-length augmentation group was a straight-hole injector. The control group was defined that pedicle screws were inserted without any cement augmentation. Six screws were inserted in each group and the maximum insertion torque was recorded. After 24 h of injecting acrylic bone cement, routine X-ray and CT examinations were performed to evaluate the distribution of bone cement. The axial pull-out force of screws was tested with the help of the material testing system 858 (MTS-858) mechanical tester. RESULTS: The bone cement injectors were consisted of the sheaths and the steel rods and the sheaths had different number of lateral holes. The control group had the lowest maximum insertion torque as compared with the 4-hole, 6-hole, 8-hole, and straight pore groups (P < 0.01), but the differences between the 4-hole, 6-hole, 8-hole, and straight pore groups were no statistical significance. The control group had the lowest maximum axial pull-out force as compared with the other four groups (P < 0.01). Subgroup analysis showed the 8-hole group (161.35 ± 27.17 N) had the lower maximum axial pull-out force as compared with the 4-hole group (217.29 ± 49.68 N), 6-hole group (228.39 ± 57.83 N), and straight pore group (237.55 ± 35.96 N) (P < 0.01). Bone cement was mainly distributed in 1/3 of the distal end of the screw among the 4-hole group, in the middle 1/3 and distal end of the screw among the 6-hole group, in the proximal 1/3 of the screw among the 8-hole group, and along the long axis of the whole screw body in the straight pore group. It might indicate that the 8-hole and straight-hole groups were more vulnerable to spinal canal cement leakage. After pullout, bone cement was also closely connected with the screw without any looseness or fragmentation. CONCLUSIONS: The bone cement injectors with different number of holes can be used to augment the pedicle screw channel. The pedicle screw augmented by the 4-hole or 6-hole sheath may have similar effects to the straight pore injector. However, the 8-hole injector may result in relatively lower pull-out strength and the straight pore injector has the risks of cement leakage as well as cement solidarization near the screw head.

Light-Emitting Conjugated Organic Polymer as an Efficient Fluorescent Probe for Cu2+ Ions Detection and Cell Imaging.

Conjugated organic polymers (COPs) have been excellent candidates because the conjugated structure occupied π structure that is useful to develop light-emitting materials. However, most COPs emitt weak luminescence owing to the H-aggregation effect. Light-emitting conjugated organic polymers (LCOP-1) possess rich butyl groups anchored in the skeleton to enhance light-emitting activity via reducing the H-aggregation effect. Owing to abundant hydroxyl and nitrogen atoms, LCOP-1 exhibits high sensitivity, selectivity, and fast response to Cu2+ ions within 1 min in comparison with the cations of Na+ , Mg2+ , Al3+ , Zn2+ , Cd2+ , Ni2+ , Cr3+ , Hg2+ , Fe3+ , Fe2+ , Pb2+ , Co2+ , etc. The detection limit can be down to nanomolar. Moreover, the sensor exhibits detection toward Cu2+ ions via a naked eye colorful change from pale-yellow to yellowish-brown. Furthermore, the light-emitting probe also successfully achieves the detection of Cu2+ ions in cells without cytotoxicity, indicating its great potentials in biological function.

Active bone material containing modified recombinant human bone morphogenetic protein 2 induces bone regeneration in the alveolar process cleft in rabbits.

The clinical application of most materials used to fill severe bone defects is limited owing to the insufficient ability of such materials to induce bone regeneration over a long repair period. The purpose of this study was to establish a model for the alveolar process cleft in rabbits to evaluate the effect of active bone material in bone defect repair. The active bone material used in this study is a new bone repair material composed of a heterogeneous collagen membrane implanted with modified recombinant human bone morphogenetic protein 2. This proposed active bone material can specifically bind to collagen. Twenty-four young Japanese white rabbits (JWRs) were selected and randomly divided into four groups (normal, control, material, and bone morphogenetic protein groups). The alveolar process cleft model was established by removing an equal volume bone at the left maxillary position. Blood samples were collected from the JWRs 3 and 6 months after the surgery to evaluate the biocompatibility of the active bone materials. Subsequently, the skull model was established, and the appearance was observed. Imaging methods (including X-ray examination and micro-computerized tomography scanning), tissue staining, and immunohistochemistry were employed for the evaluation. The bone collagen material and active bone material exhibited high biocompatibility. In addition, the ability of the active bone material to induce bone repair and regeneration was higher than that of the bone collagen material. The active bone material exhibited satisfactory bone regeneration performance in rabbits, indicating its potential as an active material for repairing congenital alveolar process clefts in humans.

Repair of alveolar cleft bone defects by bone collagen particles combined with human umbilical cord mesenchymal stem cells in rabbit.

BACKGROUND: Alveolar cleft is a type of cleft lip and palate that seriously affects the physical and mental health of patients. In this study, a model of the alveolar cleft phenotype was established in rabbits to evaluate the effect of bone collagen particles combined with human umbilical cord mesenchymal stem cells (HUC-MSCs) on the repair of alveolar cleft bone defects. METHODS: A model of alveolar clefts in rabbits was established by removing the incisors on the left side of the upper jaw bone collagen particles combined with HUC-MSCs that were then implanted in the defect area. Blood biochemical analysis was performed 3 months after surgery. Skull tissues were harvested for gross observation, and micro-focus computerised tomography (micro-CT) analysis. Tissues were harvested for histological and immunohistochemical staining. The experiments were repeated 6 months after surgery. RESULTS: Bone collagen particles and HUC-MSCs showed good biocompatibility. Bone collagen particles combined with HUC-MSCs were markedly better at inducing bone repair and regeneration than bone collagen particles alone. CONCLUSIONS: Combining HUC-MSCs with bone collagen particles provides a simple, rapid and suitable method to fill a bone defect site and treat of alveolar cleft bone defects.

Transoral intraarticular cage distraction and C-JAWS fixation for revision of basilar invagination with irreducible atlantoaxial dislocation.

BACKGROUND: The revision surgery of basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD) after a previous occipitocervical fusion (OCF) is challenging. Transoral revision surgery has more advantages than a combined anterior and posterior approach in addressing this pathology. The C-JAWS is a cervical compressive staple that has been used in the lower cervical spine with many advantages. Up to now, there is no report on the application of C-JAWS in the atlantoaxial joint. We therefore present this report to investigate the clinical outcomes of transoral intraarticular cage distraction and C-JAWS fixation for revision of BI with IAAD. METHODS: From June 2011 to June 2015, 9 patients with BI and IAAD were revised by this technique after previous posterior OCF in our department. Plain cervical radiographs, computed tomographic scans and magnetic resonance imaging were obtained pre- and postoperatively to assess the degree of atlantoaxial dislocation and compression of the cervical cord. The Japanese Orthopedic Association (JOA) score was used to evaluate the neurological function. RESULTS: The revision surgeries were successfully performed in all patients. The average follow-up duration was 18.9 ± 7.3 months (range 9-30 months). The postoperative atlas-dens interval (ADI), cervicomedullary angle (CMA), distance between the top of the odontoid process and the Chamberlain line (CL) and JOA score were significantly improved in all patients (P < 0.05). Bony fusion was achieved after 3-9 months in all cases. No patients developed recurrent atlantoaxial instability. CONCLUSIONS: Transoral revision surgery by intraarticular cage distraction and C-JAWS fixation could provide a satisfactory outcome for BI with IAAD after a previous unsuccessful posterior operation.

Surgical treatment for basilar invagination with irreducible atlantoaxial dislocation: transoral atlantoaxial reduction plate fixation vs occipitocervical fixation.

BACKGROUND: Transoral atlantoaxial reduction plate (TARP) fixation or occipitocervical fixation (OF) is an effective treatment for basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD). But, all current clinical studies involved a single surgical procedure. The clinical effects of TARP and OF operation for BI with IAAD have yet to be compared. We therefore present this report to compare the treatment of TARP and OF procedure for BI with IAAD. METHODS: Fifty-six patients with BI with IAAD who underwent TARP or OF operation from June 2011 to June 2017 were retrospectively analyzed. Among these, 35 patients underwent TARP operation (TARP group), and 21 patients underwent OF operation (OF group). We compared the difference of clinical, radiological, and surgical outcomes between the TARP and OF groups postoperatively. RESULTS: Compared with OF group, the operative time and blood loss in TARP group were lower. There was no statistical difference in the atlantodental interval (ADI), clivus canal angle (CCA), cervicomedullary angle (CMA), distance between the top of the odontoid process and the Chamberlain line (CL) and Japanese Orthopaedic Association (JOA) score between the TARP and OF groups preoperatively, but the improvements of these parameters in the TARP group were superior to those in the OF group postoperatively. The fusion rates were higher in the TARP group than those in the OF group at the early stage postoperatively. CONCLUSIONS: TARP and OF operations are effective surgical treatment for BI with IAAD, but the performance of reduction and decompression and earlier bone fusion rates of TARP procedure are superior to those of OF.

Zero-Dimensional Carbon Dots Enhance Bone Regeneration, Osteosarcoma Ablation, and Clinical Bacterial Eradication.

Zero-dimensional carbon dots (CD) and their effects on osteogenesis have been rarely studied in bone repair scaffolds. Here, we fabricate a novel CD doped chitosan/nanohydroxyapatite (CS/nHA/CD) scaffold with full potential to promote bone regeneration by a facile freeze-drying method. The CS/nHA/CD scaffolds enhanced cell adhesion and osteoinductivity in rat bone mesenchymal stem cells by up-regulating genes involved in focal adhesion and osteogenesis in vitro, which significantly improved the formation of vascularized new bone tissue at 4 weeks compared to pure CS/nHA scaffolds in vivo. Inspired by the excellent photothermal effect of CD, the scaffolds were applied in tumor photothermal therapy (PTT) under near-infrared (NIR) irradiation (808 nm, 1 W/cm2). The scaffolds significantly inhibited osteosarcoma cell proliferation in vitro and effectively suppressed tumor growth in vivo. Moreover, the CS/nHA/CD scaffolds possessed distinct antibacterial properties toward clinically collected S. aureus and E. coli, and their antibacterial activity was further enhanced under NIR irradiation. This work demonstrates that zero-dimensional CD can enhance the osteogenesis-inducing property of bone repair scaffolds and that CD doped scaffolds have potential for use in PTT for tumors and infections.

Hierarchical Microspheres Constructed from Chitin Nanofibers Penetrated Hydroxyapatite Crystals for Bone Regeneration.

Chitin exists abundantly in crab and shrimp shells as the template of the minerals, which inspired us to mineralize it for fabricating bone grafting materials. In the present work, chitin nanofibrous microspheres were used as the matrix for in situ synthesis of hydroxyapatite (HA) crystals including microflakes, submicron-needles, and submicron-spheres, which were penetrated by long chitin nanofibers, leading to the hierarchical structure. The shape and size of the HA crystals could be controlled by changing the HA synthesis process. The tight interface adhesion between chitin and HA through the noncovanlent bonds occurred in the composite microspheres, and HAs were homogeneously dispersed and bounded to the chitin nanofibers. In our findings, the inherent biocompatibilities of the both chitin and HA contributed the bone cell adhesion and osteoconduction. Moreover, the chitin microsphere with submicron-needle and submicron-sphere HA crystals remarkably promoted in vitro cell adhesion and in vivo bone healing. It was demonstrated that rabbits with 1.5 cm radius defect were almost cured completely within three months in a growth factor- and cell-free state, as a result of the unique surface microstructure and biocompatibilities of the composite microspheres. The microsphere scaffold displayed excellent biofunctions and an appropriate biodegradability. This work opened up a new avenue to construct natural polymer-based organic-inorganic hybrid microspheres for bone regeneration.

A unique procedure of joined transoral and retropharyngeal high cervical approach (JTRC) without mandibulectomy for treating upper cervical neoplasm involving both C2 and C3.

PURPOSE: To investigate a unique procedure of joined transoral and retropharyngeal high cervical approach (JTRC) without mandibulectomy for treating upper cervical neoplasm involving both C2 and C3. METHOD: A 23-year-old male patient had neoplasma involving C2 and C3 that caused pathologic fracture of C2 and bony destruction of C3. The neoplasm excision and cervical spine reconstruction were performed through JTRC approach without splitting up the mandible. In this approach, there were two surgery windows that could be applied in turns by closing or opening the mouth to gain an ideal exposure. By rotating the mandible, we could gain maximized exposure for either surgery windows. In addition, there was an overlay zone between transoral approach and high cervical retropharyngeal approach that could eliminate the blind area behind the mandible. RESULTS: All the procedures were successfully performed; the surgical incisions healed without infection. By operating alternatively between the two surgery windows, we have successfully performed neoplasm excision and cervical spine reconstruction involving both C2 and C3. Pathologic results showed metastatic renal cell cancer to the resected cervical tumor and confirmed the patient's diagnosis of tuberous sclerosis (Bourneville disease). A 3-month postoperative cervical spine radiography and CT scan demonstrated a favorable placement of the bone implant as well as a favorable instrumentation. CONCLUSION: The JTRC approach could provide good surgical exposure for treating disorders involving both upper and lower cervical spine without splitting up the mandible.

Clinical Analysis of Five Cases of AIDS-related Non-Hodgkin Lymphoma.

OBJECTIVE: Secondary malignancy is a major life-threatening complication facing patients afflicted with acquired immunodeficiency syndrome (AIDS). This study aimed to retrospectively review clinical features and treatment course of five patients with AIDS-associated non-Hodgkin lymphoma (A-NHL) in Jilin Tumor Hospital. METHODS: Five A-NHL patients were retrospectively and consecutively hospitalized at our oncological unit between January 2012 and June 2014. All patients received pre-emptive highly active antiretroviral therapy (HAART) and chemotherapy, and were subsequently followed up at the outpatient clinic. All five patients were male, aged 27-53 years, and afflicted with A-NHL involving upper jaw, right inguinal region, right-side gingiva, mediastinum, or right-side neck. Histology showed diffuse large B-cell lymphoma (n = 3) or plasmablastic lymphoma (n = 2). RESULTS: Two patients achieved complete remission after HAART and chemotherapy, whereas other three patients required a second-line treatment, with two achieving stable disease and one dying within a follow-up period of 0.5-2 years. CONCLUSION: The findings of the present study showed that A-NHL is a disease often diagnosed in the middle-to-late stages, with diverse clinical manifestations and short overall survival. In the cases reviewed in this study, HAART in combination with standard dose or high-dose chemotherapy, HAART and molecular targeted chemotherapy was administered, and these treatments proved to be effective for improving the prognosis of these patients. Moreover, the CD4+ cell count was important for determining the prognosis of patients.

Identification of a novel PHEX mutation in a Chinese family with X-linked hypophosphatemic rickets using exome sequencing.

Familial hypophosphatemic rickets (HR), the most common inherited form of rickets, is a group of inherited renal phosphate wasting disorders characterized by growth retardation, rickets with bone deformities, osteomalacia, poor dental development, and hypophosphatemia. The purpose of this study was to identify the genetic defect responsible for familial HR in a four-generation Chinese Han pedigree by exome sequencing and Sanger sequencing. Clinical features include skeletal deformities, teeth abnormalities, hearing impairments and variable serum phosphate level in patients of this family. A novel deletion mutation, c.1553delT (p.F518Sfs*4), was identified in the X-linked phosphate regulating endopeptidase homolog gene (PHEX). The mutation is predicted to result in prematurely truncated and loss-of-function PHEX protein. Our data suggest that exome sequencing is a powerful tool to discover mutation(s) in HR, a disorder with genetic and clinical heterogeneity. The findings may also provide new insights into the cause and diagnosis of HR, and have implications for genetic counseling and clinical management.

Biomechanical Effects of Masticatory Muscles on Human Mandible After Reconstructed Mandibulectomy Tumor.

BACKGROUND: This study aimed to analyze and compare the stress distribution on the condylar process. This study was also designed to determine the effect of closing and opening muscle groups of the jaw on mandibular stability after mandibular tumor osteotomy reconstruction by three-dimensional finite element analysis. MATERIALS AND METHODS: Three-dimensional reconstructed mandibles were used and divided into 2 groups: (1) 6 patients with normal mandible and (2) 6 mandibular tumor patients who underwent osteotomy reconstruction. Computed tomography scans of normal and reconstructed mandibular tumor osteotomy patients were obtained. Three-dimensional models were reconstructed using Simpleware 5.0 software. Boundary constraint and load conditions were applied. The solution process was run, and the actions of closing and opening muscle groups were simulated and calculated using finite element analysis software. Statistical software was used for analysis of the condylar stress distribution. RESULTS: A significant difference was observed in stress distributions on the anterior condyle of the healthy volunteers and the reconstructed mandibular tumor osteotomy patients, who were subjected to tumor osteotomy surgery in the opening muscle groups (P < 0.05). By contrast, no significant difference was observed in the posterior condyle of the opening muscle group and the closing muscle group (P > 0.05). CONCLUSIONS: Muscular imbalance in postoperative mandibular tumor reconstruction was changed in patients. We adjusted the force of the mandible closing muscle intraoperatively to achieve muscle balance. Therefore, poor swallowing, failure to retain saliva, speech impairment, and esthetic disfigurement were repaired and/or resolved.

Treatment of basilar invagination with atlantoaxial dislocation: atlantoaxial joint distraction and fixation with transoral atlantoaxial reduction plate (TARP) without odontoidectomy.

PURPOSE: Although direct transoral decompression and one-stage posterior instrumentation can obtain satisfactory cord decompression for the treatment of basilar invagination with atlantoaxial dislocation, surgical injuries run high as combinative anterior-posterior approaches were necessary. Furthermore, the complications will rise notably when involvement of dens and/or clivus in the decompression necessitates relatively complicated surgical techniques. First initiated in 2005, transoral atlantoaxial reduction plate (TARP) works as an internal fixation for the treatment of basilar invagination with irreducible atlantoaxial dislocation. Therefore, this article aimed to describe several operative experiences about this approach, which has delivered successful decompression, fixation and fusion. METHODS: 21 consecutive patients with basilar invagination underwent the TARP operation. The pre- and postoperative medulla-cervical angles were measured and compared. The JOA scores of spinal cord function were calculated pre- and post-operatively. 20 cases (20/21) were followed up to average 12.5 months. RESULTS: Symptoms of all the 20 cases were relieved in different degrees. The postoperative imaging showed the odontoid processes obtained ideal reduction and the internal fixators were all in good position. The medulla-cervical angle was correctd from an average (± standard deviation) 128.7° + 11.9° (n = 20) before surgery to 156.5° + 8.1° (n = 20) after surgery (P < 0.01). The average preoperative and postoperative Japaneses Orthopedic Association scores were 11.25 (n = 20) and 15.9 (n = 20), respectively, indicating 76 % improvement. Screw-loosening was observed in one patient due to severe osteoporosis. After a revised operation with a TARP in another size, the neurological symptoms showed no obvious improvements. Then the treatment was terminated. CONCLUSIONS: The TARP operation and intra-operative traction could reduce the odontoid process superiorly migrating into the foramen magnum, directly ease the ventral compression of spinal cord, and fix the reduced atlantoaxial joints through a single transoral approach without the need of a posterior operation. In this stury, 21 patients were evaluated and 20 did well with TARP operation. The preliminary clinical result was satisfactory.