The mechanical properties of artificial intervertebral disc (AID) are related to long-term reliability of prosthesis. There are three testing methods involved in the mechanical performance evaluation of AID based on different tools: the testing method using mechanical simulator, in vitro specimen testing method and finite element analysis method. In this study, the testing standard, testing equipment and materials of AID were firstly introduced. Then, the present status of AID static mechanical properties test (static axial compression, static axial compression-shear), dynamic mechanical properties test (dynamic axial compression, dynamic axial compression-shear), creep and stress relaxation test, device pushout test, core pushout test, subsidence test, etc. were focused on. The experimental techniques using in vitro specimen testing method and testing results of available artificial discs were summarized. The experimental methods and research status of finite element analysis were also summarized. Finally, the research trends of AID mechanical performance evaluation were forecasted. The simulator, load, dynamic cycle, motion mode, specimen and test standard would be important research fields in the future.
ObjectiveTo summarize the research status of mandibular sensory dysfunction after transoral endoscopic thyroidectomy vestibular approach (TOETVA), and explore its potential treatment methods and existing problems, and provide ideas and methods for future clinical treatments or research. MethodThe domestic and foreign literatures about peripheral nerve injury and its treatment after TOETVA were searched and reviewed. ResultsMental nerve injury was considered to be the main cause of mandibular sensory dysfunction after TOETVA. Due to the lack of unified definitions and assessment standards, the true incidence remained unclear. In order to reduce the risk of mental nerve injury, methods such as exposing the mental nerve and combining vestibular approaches during surgery had certain advantages. In terms of treatment, several methods promoting nerve repair were noteworthy, including B vitamins, nerve growth factors, physical therapy and so on. In addition, some auxiliary treatments of Traditional Chinese Medicine also showed effectiveness in promoting nerve regeneration. ConclusionsIt is essential to avoid damage to the mental nerve and mandibular tissues during surgery. For patients with significant complaints postoperatively, active treatment should be pursued. Establishing objective and quantifiable standards for evaluating mandibular sensory dysfunction and seeking effective clinical plans through a multidisciplinary approach may be the direction for future research.
ObjectiveTo observe the clinical effect of unilateral puncture percutaneous kyphoplasty (PKP) through transverse process-pedicle approach (TPA) for the treatment of lumbar osteoporotic vertebral fractures (OVF).MethodsFrom January 2014 to June 2019, a total of 220 OVF patients (321 fractured vertebral bodies) were enrolled, and PKP was performed by unilateral TPA puncture. The distribution of bone cement in vertebral body exceeding the midline of vertebral body was defined as the success of puncture, and the success rates of puncture of different vertebral bodies were recorded. Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), anterior and middle heights of the vertebral body, and the local Cobb angle were compared between three time points namely before operation, 1 day after operation, and 6 months after operation. Surgery-related complications were recorded.ResultsThe 220 patients included 57 males and 163 females, with a mean age of (70.3±6.5) years, a mean course of disease of (18.7±17.7) d, and a mean bone mineral density of ?3.3±0.6. The success rate of puncture from L1 to L5 was 81.7% (85/104), 95.2% (80/84), 100.0% (69/69), 97.6% (41/42), and 72.7% (16/22), respectively. The mean volume of bone cement injected into the vertebral bodies was (5.8±0.9) mL. Two patients were followed up for less than 6 months because of death or loss to follow-up, and the other 218 patients were followed up for 6-57 months, with an average of (19.6±8.7) months. Before surgery, 1 day after surgery, and 6 months after surgery, the median (lower quartile, upper quartile) of VAS scores was 6 (6, 8), 1 (1, 2), and 2 (1, 2), respectively, with statistically significant differences in all the two-two comparisons (P<0.017). At the three time points, the median (lower quartile, upper quartile) of ODI was 61% (54%, 66%), 26% (22%, 30%), and 25% (24%, 31%), respectively, the mean height of anterior vertebral body was (18.3±2.8), (22.6±3.0), and (22.6±3.1) mm, respectively, the mean height of middle vertebral body was (17.8±2.2), (22.9±2.8), and (22.9±2.7) mm, respectively, the mean local Cobb angle was (19.9±2.6), (14.4±2.8), (14.4±2.8)°, respectively, and the values at 1 day and 6 months after surgery all differed from those before surgery (P<0.017). A total of 32 cases (42 vertebrae) had bone cement leakage, of whom 4 cases had related symptoms. There were 32 re-fractures of the vertebral bodies, including 18 adjacent vertebral body fractures, with an incidence rate of 5.6%. There were 3 vertebral infections after operation, the incidence was 0.9%.ConclusionPatients with OVF of the lumbar spine undergoing unilateral TPA puncture for PKP surgery have a high success rate, definite clinical effect, and satisfactory correction of local deformities.
Zero profile cervical interbody cage is an improvement of traditional fusion products and necessary supplement of emerging artificial intervertebral disc products. When applied in Anterior Cervical Decompression Fusion (ACDF), zero profile cervical interbody cage can preserve the advantages of traditional fusion and reduce the incidence of postoperative complications. Moreover, zero profile cervical interbody cage can be applied under the tabu symptoms of Artificial Cervical Disc Replacement (ACDR). This article summarizes zero profile interbody cage products that are commonly recognized and widely used in clinical practice in recent years, and reviews the progress of structure design and material research of zero profile cervical interbody cage products. Based on the latest clinical demands and research progress, this paper also discusses the future development directions of zero profile interbody cage.
ObjectiveTo investigate the reasons for failure to treat thoracolumbar tuberculosis by anterior internal fixation and its countermeasures.
MethodsA total of 485 patients with thoracolumbar spinal tuberculosis underwent anterior focus clearance and fixation from January 2005 to January 2012. Eighteen of them failed with a rate of 3.71%. Screws were pulled out in two patients. Vertebra cutted by screws occurred in three patients. In another three patients, screws dropped into the intervertebral disc. Tuberculosis relapsed in 10 patients (5 accompanied with spinal deformity, 2 with pure malunion, 2 with abscess formation, and 1 with sequestra). Twelve of the patients underwent two-stage posterior pedicle screw internal fixation and anterior focus clearance and autogenous bone grafts fusion. Four were treated by shifting antituberculosis drugs and staying in bed. Two were cured by multiple abscesses puncture and antituberculosis injection.
ResultsThese patients were followed up for 15~30 months. Twelve cases of spinal tuberculosis were completely cured and 6 cases of them got clinical cure. However, 3 cases of them had scoliosis deformity followed and 1 had kyphosis. No tuberculosis relapse, cold abscess or sinus formation, or pedicle screw internal fixation failure occurred again.
ConclusionAlthough there are many complications of anterior internal fixation for spinal tuberculosis, anterior internal fixation is still a perfect choice if we can make an appropriate choice of operation and strengthen the management after operation.
Total lumbar disc replacement is an alternative to interbody fusion for the effective treatment of symptomatic degenerative disc disease. This paper reviewed the history of ball-on-socket type artificial lumbar disc (ALD) prosthesis, which is a typical ALD prosthesis and summarized the ALD prosthesis research progress, according to different materials such as metal-on-metal, metal-on-polymer, and polymer-on-polymer prosthesis. The structural design factors of ball-on-socket type ALD prosthesis were analyzed and its prospect of development was also presented. The purpose of this paper is to provide a theoretical reference for the design of the ball-on-socket ALD prosthesis by reviewing the current state of ball-on-socket type ALD prosthesis.
