Clinical report of cervical arthroplasty in management of spondylotic myelopathy in Chinese

OBJECTIVES: To investigate clinical effects and manual operational point of Bryan cervical disc prosthesis in Chinese, to observe the stability and range of movement (ROM) post-operatively. METHODS AND MATERIALS: From 2003,12 to 2005,12, Bryan disc prosthesis replacement applied in 83 cases (102 levels) of cervical spondylotic myelopathy (CSM) after anterior decompression in our hospital. Clinical (JOA grade and Odom's scale) and radiological (X-ray of flexion, extension; left and right bending position) follow-up was performed. Systemic radiographic study about stability and ROM of replaced level post operationally were measured. CT or MRI scans were applied in all cases to evaluate the signs of the prosthesis deflexion and hetero-ossification in the replaced levels. RESULTS: At least 12 months follow-up were done in 65/83 of these paients. All of 83 patients were improved according to Odsm's scale. JOA score increased from average 8.7 to 15.5. There was no prosthesis subsidence. Replaced segment achieved stability and restored partial of normal ROM 4.73°(3.7°–5.9°) early postoperation and 8.12°(5.8°–13.6°) more than 12 months postoperation in flex and extension position. No obvious loss of lordosis was found. CT or MRI follow-up shows position deflexion of the prosthesis metal endplates (<1.5 mm) in 14/77 levels and (1.5~3 mm) in 4/77. heter-ossification was found in the replaced levels only in 2 cases. CONCLUSION: Byran cervical disc prosthesis restored motion to the level of the intact segment in flexion-extension and lateral bending in post-operative images. At the same time, it can achieve good anterior decompression treatment effect and immediate stability in replaced 1 or 2 levels, and which is a new choice for the treatment of CSM

Temporary use of shape memory spinal rod in the treatment of scoliosis

NiTinol shape memory alloy is characterized by its malleability at low temperatures and its ability to return to a preconfigured shape above its activation temperature. This process can be utilized to assist in scoliosis correction. The goal of this retrospective study was to evaluate the clinical and radiographic results of intraoperative use of shape memory alloy rod in the correction of scoliosis. From May 2002 to September 2006, 38 scoliosis patients (ranging from 50° to 120°; 22 cases over 70°) who underwent shape memory alloy-assisted correction in our institute were reviewed. During the operation, a shape memory alloy rod served as a temporary correction tool. Following correction, the rod was replaced by a rigid rod. The mean blood loss at surgery was 680 ± 584 ml; the mean operative time was 278 ± 62 min. The major Cobb angle improved from an average 78.4° preoperatively to 24.3° postoperatively (total percent correction 71.4%). In 16 patients with a major curve <70° and flexibility of 52.7%, the deformity improved from 58.4° preoperatively to 12.3° postoperatively (percent correction, 78.9%). In 22 patients with a major curve >70° and flexibility of 25.6%, the deformity improved from 94.1° preoperatively to 30.1° postoperatively (percent correction, 68.1%). Only one case had a deep infection. There were no neurologic, vascular or correction-related complications such as screw pullout or metal fracture. The study shows that the intraoperative use of a shape memory rod is a safe and effective method to correct scoliosis

Comparative analysis between shape memory alloy-based correction and traditional correction technique in pedicle screws constructs for treating severe scoliosis

The three-dimensional correction of severe rigid scoliosis has been improved by segmental pedicle screw instrumentation. However, there can be significant difficulty related to the use of a rigid rod, especially in the apex region of severe scoliosis. This study is a retrospective matched cohort study to evaluate the advantages of Nitinol shape memory alloy (SMA) rod-based correction by comparing the clinical and radiographic results obtained from using a temporary SMA rod and those from a standard rod in the correction of severe scoliosis. From May 2004 to September 2006, patients with matched curve type, ages at surgery, operative methods and fusion levels in our institute and instrumented with either SMA rods (n = 14) or traditional correction techniques (n = 16) were reviewed. In SMA group, the SMA rods served as a temporary intraoperative tool for deformity correction and were replaced by standard rods. The blood loss at surgery averaged 778 ± 285 ml in the traditional group and 585 ± 188 ml in the SMA group (P < 0.05). Operative time averaged 284 ± 53 min in the SMA group and 324 ± 41 min in the traditional group (P < 0.05). In the SMA group, the preoperative major curve was 92.6° ± 13.7° with a flexibility of 25.5 ± 7.3% was corrected to 29.4° ± 5.7° demonstrating a 68.4% immediate postoperative correction. In the traditional group, the preoperative major curve was 88.6° ± 14.6° with a flexibility of 29.3 ± 6.6% was corrected to 37.2° ± 7.3° demonstrating a 57.8% immediate postoperative correction. There was a statistic difference between the SMA group and traditional group in correction rate of the major thoracic curve. In the SMA group, one case suffered from deep infection 2 months postoperatively. In the traditional group, 6 of 16 cases suffered pedicle screw pull out or loosening during placement of the standard rod at the apex vertebrae on the concave side. In three cases, the mono-axial pedicle screws near the apex were abandoned and in five cases replaced with poly-axial pedicle screws. This study shows that the temporary use of SMA rod may reduce the operative time, blood loss, while improve the correction of the coronal plane when compared with standard techniques

STUDY ON STRIDE LENGTH, RATE, ANS SPEED OF 100m SPRINTE RUNNING WITH FIVE KINDS OF SPEED

Studying on sprint not only is important to this event itself, but also will accelerate the development of other events. Speed is an important index in sprint event and it is relate to stride length and stride rate. In this paper, we studied and analyzed the relationship of stride length. stride rate and speed of seven sprinters when the subjects run with five kinds of speed. In the trial, we filmed the technique of seven athletes with M9500 normal speed camera and got the data with which we analyzed the technique using SHIXUN image analysis system. The results show: (1) it is correct that seven athletes grasp gradual increase of speed, which prove that the choose of the athletes is believable; (2) when the speed increases, the stride length and the stride rate change with diHerent extent. But on the whole, it's tendentious. (3) When speed increased, stride length was the primary factor at low speeds while stride rate was the primary factor at high speeds. We suggest that seven athletes in this study should pay attention to strengthening the exercise of increasing the stride rate in usual training

The Effect of Factors on the Radiation Noise of High-Speed Full Ceramic Angular Contact Ball Bearings

Ceramic angular contact ball bearing is widely used in a high-speed motorised spindle because of their excellent properties such as wear resistance, high temperature resistance, and corrosion resistance. In this study, the characteristics and influencing factors of the radiation noise for a full ceramic angular contact ball bearing applied in the motorised spindle are investigated. Based on a single factor test method, the variations of bearing noise with preload, oil supply, and rotation speed were investigated, and then, the optimal preload and oil supply under the specific speed were obtained. The sound field directivity in the circumferential distribution of the bearing noise was discussed, and the reasons for the uneven distribution of the sound field were elucidated. According to the experimental results, a prediction model on the radiation noise of a full ceramic angular contact ball bearing under certain conditions was proposed. The conclusions will provide a reference for reducing the radiation noise of full ceramic angular contact ball bearings in high-speed operation and improving the bearing performance

The maximum positive curvature recognition method to determine etch profiles in wet etching of quartz on AT and BT cuts

This paper presents a method to quickly determine the transient and stable profiles of trenches, cavities, and mesas formed by anisotropic wet chemical etching on AT and BT cut quartz wafers. Since most quartz orientations have low etch rates and both AT and BT cuts have no trigonal symmetry (unlike the Z cut), it is typically difficult to explain which sidewalls will appear on a given trench for a particular mask alignment on these cuts. By considering the complete etch rate distribution obtained from an etched quartz hemisphere we show that a maximum positive curvature recognition method can be used in order to determine a small number of key orientations, which will directly appear as the transient and stable sidewalls in the experimental trench profiles on both the AT and BT cuts. Similarly, the proposed method accurately explains the formation of complex facets on square cavities as well as on the top, middle and bottom regions of micro-needle arrays etched on the AT and BT cuts. This indicates that the etch profiles of any cut of the trigonal crystal can be determined by using the location of the proposed key orientations.Funding Agency: 10.13039/501100001809-National Natural Science Foundation of China; Department of Science and Technology the Ramón y Cajal Fellowship Program by the Spanish Ministry of Science and Innovation.Peer reviewe