[Imaging measurement of anterior internal fixation for the cervicothoracic junction and its clinical significance].

OBJECTIVE: To measure important parameters of anterior internal fixation for the cervicothoracic junction by us-ing imaging measurement, and provide reference for cervicothoracic junction surgery and design of steel plate screw internal fixation. METHODS: From June to November 2012, 120 health people's median sagittal plane MRI of cervical spine were ran-domly collected. Of the 120 cases, there were 58 males and 62 females with an average age of 48.3 +/- 13.7, ranging the age of 20 to 78 years old. The anterior,middle and posterior height of vertebral, anterior, upper, medium and lower sagittal diameter, an-terior height of different segments and Cobb angle were measured by measuring machine in the PACS system. RESULTS: The an-terior, middle and posterior height of vertebral, medium and lower sagittal diameter gradually increased from cranial to caudal of cervicothoracic junction (P < 0.01). For single vertebral,posterior> anterior>middle height (P < 0.01), lower > upper>medium sagittal diameter (P < 0.01). The lower sagittal diameter of upper vertebral body was close to upper sagittal diameter of lower vertebral body. Cobb angle of male was (7.61 +/- 3.85) degrees, while female's was (5.58 +/- 2.59) degrees . CONCLUSION: During the anterior in-ternal fixation of cervicothoracic junction, it is suggested that the entry points of upper vertebral body should locate on the lower and middle 1/3 of vertebral body, and screws could slightly incline towards cranial,the entry points of lower vertebral body should locate on the upper and middle 1/3 of vertebral body, while screws could slightly incline towards caudal, also can be prebent according to Cobb angle of health.

A biomechanical study on the interosseous membrane and radial head in cadaveric forearms.

OBJECTIVE: Our aim was to evaluate the biomechanical properties of the interosseous membrane (IOM) and radial head and investigate the pathomechanics of the Essex-Lopresti injury. METHODS: Twelve adult fresh frozen upper limbs of human cadavers were chosen for test. First, the 12 intact specimens were mounted onto a materials testing machine to carry out biomechanical tests in pronation, supination and neutral positions, respectively. An axial load of 100 N was applied along the longitudinal axis of the forearm for 30 seconds in each position. Then, the twelve specimens were randomly divided into two groups. The radial head was resected in 6 specimens. And the central band of IOM was severed in another 6 specimens. Each group was tested by the same method. Finally, both the radial head and the IOM were excised in all specimens and biomechanical tests were performed. RESULTS: The rotational position of the forearm or simple severance of the IOM had no effect on longitudinal displacement. The radial longitudinal displacement increased significantly after resection of the radial head. The severance of the IOM had no effect on compressive stiffness of the radius. However, compressive stiffness of the radius decreased significantly after resection of the radial head. CONCLUSION: The radial head fracture combined with the IOM injury was the most important cause of the Essex-Lopresti injury, and the radial head fracture was the major factor. The IOM was the major structure to maintain the longitudinal stability of the forearm after resection of the radial head.

Three-dimensional reconstruction of the superior mediastinum from Chinese Visible Human Female.

PURPOSE: This research aimed to construct three-dimensional (3D) visible models of the superior mediastinum for anatomic study and surgical approaches to the superior mediastinum. METHOD: Sectional images of the superior mediastinum were acquired through the Chinese Visible Human Female (VCHF) database. One hundred eighty images of the superior mediastinum were imported into Photoshop CS and the images were converted into a JPEG format. Surface and volume reconstruction were performed by 3D Doctor 3.5 and Amira 4.0 software programs on an ordinary personal computer, respectively. RESULT: The surface and volume reconstruction of the superior mediastinum were successful. The surface reconstruction model allowed rotation and magnification of the superior mediastinum structures as well as displayed the contours of reconstructed structures individually or as a composite with any other selected structure. Volume reconstruction displayed abundant internal detail of reconstructed images in transverse, coronal, sagittal, and random oblique sections. CONCLUSION: Three-dimensional, visible models of the superior mediastinum based on the sectional images of VCHF can provide unique insight into the anatomy of superior mediastinum. These models provide an excellent adjunct to the anatomy curriculum in medical schools and an invaluable tool for the practicing surgeon planning an operation in this complex anatomic region.