[Value of multislice spiral CT scanning and three-dimensional reconstruction in selecting optimal length and shape of mandible internal fixation material].

OBJECTIVE: To investigate the value of multislice spiral CT (MSCT) scanning and three-dimensional reconstruction in selecting optimal length and shape of mandible internal fixation material. METHODS: Three-dimensional reconstruction of the mandible was performed in 5 cases by MSCT scanning and the length of the mandible for operation was measured. Some isometric points were chosen on the mandibular curve and the distance from these points to the two ends of the curve was measured to depict the mandibular curve using a self-designed skeletal curve-depicting software. The optimal length and shape of the material for internal fixation was then determined. RESULTS: After removal of the soft tissues and other irrelevant bones from the reconstructed three-dimensional mandible with clear view from any directions, the length of the mandible was accurately measured with the software. The physiological curve of the mandible was generated after determination of the distances from the chosen points on the mandibular curve and to the two ends of the curve for precise determination of the length and shape of the material for internal fixation. CONCLUSION: Three-dimensional mandible reconstruction with MSCT and measurement facilitates the determination of the optimal length and shape of the internal fixation material to enhance the attachment between the material and the bone surface and consequently the therapeutic effects.

[Biomechanical study of double-plate fixation for comminuted fractures of the distal femur].

OBJECTIVE: To explore the new treatment approach for comminuted fractures of the distal femur. METHODS: Supra- and intercondylar comminuted fractures were induced in the femurs of 20 fresh adult cadavers, 10 of which received fixation with lateral steel plates and medial polyethylenes plates while the rest with single plate in the lateral only. Biomechanical tests of bending, torsion and compression were performed. RESULTS: Biomechanical test demonstrated that double-plate fixation provided better resistance to compression (P<0.05) as well as bending and torsion (P<0.01) than single-plate fixation did. CONCLUSION: Double-plate fixation is effective and may have potential clinical value in treating comminuted fractures of the distal femur.

[mRNA expression of recombinant human bone morphogenetic protein 7 in skeletal muscle satellite cells with retroviral vector-mediated rhBMP7 gene transfection].

OBJECTIVE: To detect the expression of recombinant human bone morphogenetic protein7 (rhBMP7) in skeletal muscle satellite cells (SMSCs) with rhBMP7 gene transfection mediated by retroviral vector. METHODS: rhBMP7 gene was reconstructed in retroviral vector and transferred into packaging cells PT67 via liposome reagent, with the positive cell clones selected with G418. In vitro cultured SMSCs were transfected with the virus granules secreted by PT67 cells and followed by G418 selection. Reverse transcriptase-polymerase chain reaction was utilized for analysis for rhBMP7 mRNA in the transfected cells. RESULTS: rhBMP7 retrovirus vector was successfully constructed and transferred into PT67 cells, and abundant mRNA expression of rhBMP7 was observed in the skeletal muscle satellite cells transfected with the virus and selected with G418. CONCLUSION: rhBMP7 gene can be transferred into the skeletal muscle satellite cells via retroviral vector to yield effective rhBMP7 mRNA expression.

[An experimental study of treatment of comminuted distal femur fracture with locked double- plating].

OBJECTIVE: To explore new techniques for the treatment of comminuted distal femoral fractures to promote functional restoration and reduce the complications of the fracture. METHODS: Sixteen adult canines were selected for this study, and the experimental and control hindlimb for each canine were randomly determined. Distal comminuted fracture (AO/ASIF Type C2) was induced in both sides of the canine's femurs, and one side was fixed with the double plates (steel plate and polyethylene plate), whereas the other with a single steel plate. By the end of 3, 6, 9 and 12 weeks respectively after surgery, 4 of the dogs were used for weight-bearing observation and radiological and histological examination of the limbs. RESULTS: In comparison with dogs in single plate group, double plate fixation resulted in earlier recovery of weight bearing, more abundant and better callus, finer callus moulding and quicker healing. There were slightly more inflammatory cells, however, in the tissues under the polyethylene than those under the steel plate. CONCLUSION: Locked double-plate internal fixation is an excellent alternative for treating comminuted fractures of the distal femur, and may have its potential use in clinical settings.

[Ultrasound, abdominal X-ray and dual-source CT in the diagnosis of colon tumor mechanical obstruction].

OBJECTIVE: To study the value of ultrasound, abdominal X-ray, and dual-source CT (DSCT) in the diagnosis of colon tumor obstruction. METHODS: A retrospective analysis was conducted among 45 patients who were admitted to our department between October 2010 and August 2011 for abdominal pain. All the patients underwent ultrasound, abdominal X-ray and DSCT examinations and subsequent surgical interventions, which confirmed the diagnosis of colon tumor obstruction. RESULTS: DSCT diagnosis was obviously more efficient than ultrasound and X-ray in detecting colon obstruction by neoplasms, and could better predict the position of the obstruction. Complete information of the vessels in the surgical field could be obtained by DSCT imaging three-dimensional reconstruction. CONCLUSIONS: Compared with ultrasound and X-ray, DSCT is more effective in the diagnosis of colon tumor obstruction by acquiring more thorough information by imaging reconstruction and should be considered for a rapid and accurate diagnosis.

[High-field MRI and pathological diagnosis of supratentorial primitive neuroectodermal tumors].

OBJECTIVE: To analyze the magnetic resonance imaging (MRI) features of supratentorial primitive neuroectodermal tumors (sPNET) and improve the diagnosis of this disease. METHODS: MRI manifestations of 14 cases of PNET were retrospectively analyzed and compared with their pathological features. RESULTS: The supratentorial lesions involved the occipital lobe in 4, frontal lobe in 3, fronto-occipital lobe in 2, temporo-occipital lobe in 3, lateral ventricle in 1 case and the saddle region in 1. All the lesions were large in volume and most of them presented heterogeneous signals in MRI. Of the 14 cases, 12 showed cystic degeneration and necrosis, 2 had hemorrhage and 6 showed signs of emptied small blood vessels. Twelve cases had heterogeneous enhancement and 2 had moderate enhancement. Pathologically, 10 cases of neuroblastomas were identified, along with 3 ganglioneuroblastomas and 1 atypical rhabdoid tumor. CONCLUSION: MRI findings of PNET are rather characteristic to assist in the diagnosis and treatment of the disease, but a final definite diagnosis still relies on pathological examination.

[Imaging findings of craniopharyngioma in relation to its surgical management: a retrospective analysis].

OBJECTIVE: To analyze the CT and magnetic resonance imaging (MRI) findings of craniopharygioma and explore the correlation between the pathological findings and clinical features of the disease. METHODS: The CT and MRI findings of 123 pathologically confirmed craniopharygioma cases were reviewed retrospectively in conjunction with the pathological findings and surgical data. RESULTS: This patient cohort consisted of 70 male and 53 female patients with their age ranging from 1 to 72 years (mean 23.82 years). Of the 123 craniopharyngioma patients, 59 were found to have adamantinous craniopharyngiomas, 41 had papillary squamous craniopharyngiomas, and 23 had mixed tumors. Solid tumor was found in 18 cases, cystic tumor in 38 cases, and calcification in 78 cases; in 23 cases, the posterior of the tumor did not exhibit clear boundary from the wall of the three cerebral ventricles, and in 11 cases CT and MRI displayed hypophysial stalk, which was found intraoperatively in 53 cases. CONCLUSIONS: MRI allows clear vision of the range of craniopharyngioma involvement and the anatomical structures surrounding the tumor. CT, on the other hand, shows better performance in displaying the calcification foci. Accurate identification of the site, dimension, calcification patterns and relation between the hypophysial stalk and hypothalamus by the imaging modalities significantly benefits the optimization of the surgical plan for the tumor.

[Clinical value of multislice spiral CT in caudal block].

OBJECTIVE: To explore a new method for body surface orientation of the puncture site, determination of the direction of the needling and puncture depth for caudal block. METHODS: Three-dimensional reconstruction of the pelvis was performed in 8 cases for measuring the distances between the sacral hiatus and the planned site of anesthetic delivery and the size of the sacral hiatus. After image processing with the technique of shaded surface display (SSD), the shapes of sacral hiatus and sacral tube were evaluated. RESULTS: Three-dimensional reconstruction of the pelvis in the 8 cases allowed clear view from any directions of the sacral hiatus and sacral tube and accurate measurement of the size of the sacral hiatus. After simulated cutting of half of the rumpbone, the distances between the sacral hiatus and the drug injection site were accurately measured. With these measurements, accurate preoperative localization of the puncture site on the skin was achieved and the anesthesia was successful in all the cases. CONCLUSIONS: This technique can provide accurate data for localization of the puncture site on the skin and determination of the direction of the needling and the puncture depth for caudal block to increase the successful rate of anesthesia, lower the operative risks and allow simulated operative training.

[Finger reconstruction with extended free second toe flap transfer].

OBJECTIVE: To investigate an ideal method for finger reconstruction with extended the second toe flap transfer. METHODS: The second toe free flap was created, combined with an pedicled skin flap from the fibular side of the great toe inlaid in the ventral side of the second toe, a double-wing flap and the distal part of the metatarsal bone. The composite free flap was transferred by vascular anastomosis for finger reconstruction. RESULTS: The reconstructed finger exhibited nice looking and better function. The procedure had little influence to the appearance and function of the donor foot. CONCLUSION: This method is effective in ameliorating the appearance and function of the reconstructed finger with the second toe transfer.

[Fabrication of laryngeal cartilage by means of tissue engineering technique].

OBJECTIVE: To explore the method of fabricating tissue engineered laryngeal cartilage. METHODS: The rib and articular cartilage of infant New Zealand white rabbits were harvested in sterile condition. The chondrocytes were separated by collagenase digestion and cultured in vitro for 3 passage. Serial steps of solution casting, extrusion molding and particulate leaching were used to make larynx-shaped biomaterial models with poly(3-hydroxybutyrate-co-3-hydroxyhexanoate, PHBHH). The chondrocytes were seeded onto PHBHH scaffolds to form cell-PHBHH composites, which were subsequently in vitro for one week. After that, the measure of filling inner space of cell-PHBHH composites together with wrapping total composites using either greater omentum (n = 9) or fascia flap and muscle (also n = 9) in experimental groups was taken to implant the larynx-shaped biomaterial models seeded with chondrocytes into the belly and the back of adult New Zealand white rabbits. Control groups (every group n = 3) were the same measure as experimental groups but without chondrocyte on PHBHH scaffolds. Finally, morphological observation, HE staining & special staining and immunohistochemical test were conducted to assess cartilage regeneration and its shape at different period following implantation. RESULTS: The rate of viable cell in the final cell suspension was (93 +/- 2)% after well-controlled prolongation of digestion trypsin. Similar to that by traditional procedures (94 +/- 2)% (P > 0.05). The larynx-shaped PHBHH models with edges and corners of laryngeal cartilage made by us appeared to be hollow half-trumpet shape and its porosity was more than 90%. It showed that chondrocytes equally attached to the surface of porous PHBHH and filled within porousness with scanning electron microscopic examination. Tissue engineered larynx-shaped specimens could alternatively be harvested with the above mentioned two different implantation measures. The specimens presented to be similar to that before implantation in gross shape. It was demonstrated to be cartilaginous tissue through histological and immunohistochemical examination. Furthermore, There was nearly no difference between two kinds of tissue engineered laryngeal cartilage with two measures of implantation in morphology and histology. CONCLUSIONS: The regeneration of tissue engineered cartilage in vivo is not influenced by the chondrocytes harvested by improvement of well-controlled prolonged digestion with trypsin during in vitro cell culture. It seems that PHBHH may be used as scaffold in cartilage tissue engineering and wrapping together with filling method with either greater omentum or fascia flap and muscle is appropriate for fabricating tissue engineered laryngeal cartilage.