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.
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.
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.
ObjectiveTo investigate the effect of one-stage posterior reduction single nail and rod fixation combined with the anterior operation on lower cervical fracture-dislocation combined with unilateral locked facet.MethodsA retrospective analysis of 28 patients with lower cervical fracture-dislocation combined with unilateral locked facet who underwent one-stage posterior-anterior approach surgery between June 2012 and March 2017 were conducted. The Cobb angle, vertebral body horizontal displacement, height of intervertebral space, recovery of nerve function and operative complications were observed before and after operation.ResultsAll patients were followed up for 12-24 months, with an average of (18.9±4.7) months. All the patients received good reposition after operation without complications such as large blood vessels, trachea, esophagus, spinal dura mater injury and so on. The incisions healed well in all patients. Postoperative complications: postoperative hoarseness and dysphagia occured in 3 cases, pharynx and larynx pain in 8 cases, pulmonary infection in 1 case, and hyponatremia in 2 cases; all patients recovered after the related symptomatic treatment. Postoperative X-ray showed that all the patients were completely corrected without residual small joint semi dislocation and kyphosis. No spinal cord or nerve injury aggravators occurred after surgery. The neurological function of all patients was improved to different degrees 12 months after operation. American Spinal Cord Injury Association (ASIA) classification showed that, of the 6 cases classified as type B preoperatively, 4 cases turned into type C and 2 cases into type D postoperatively; of the 13 cases classified as type C preoperatively, 10 cases turned into type D and 3 into type E postoperatively; and all the 8 cases classified as type D preoperatively turned into type E postoperatively. The ASIA scores increased by 1-2 levels compared with those before operation (P<0.05). The height of cervical intervertebral space, physiological curvature and cervical stability of all patients were well maintained 7 days and 12 months after operation, which were significantly improved compared with those before operation (P<0.05). There was no significant difference between the two follow-up visits at 7 days and 12 months after operation. The Japanese Orthopaedic Association score at 12 months after operation (14.6±2.3) was significantly better than that before operation (6.8±2.6), and the average improvement rate was (79.6±18.8)% (P<0.05). No complications such as screw loosening, fracture or displacement occurred during follow-up.ConclusionOne-stage posterior reduction single nail and rod fixation combined with the anterior operation is safe and effective for the treatment of lower cervical fracture-dislocation combined with unilateral locked facet.