The Development And Clinical Application Research Of Pedicle In Vitro Restorer Based On Traditional Manual Reduction

Objective:(1)To evaluate biomechanical effects of the Pedicle In Vitro Restorer used in percutaneous vertebroplasty.(2)To study the clinical application value of Pedicle In Vitro Restorer combined with manual reduction in percutaneous vertebroplasty. Method:(1)16fresh thoracic and lumbar vertebraes were used,(T8-T12,L1-L3),studing biomechanical fatigue properties of Pedicle In Vitro Restorer by biomechanical experimental stress analysis.Aged60to75years old, male or female.(2)60patients with osteoporotic compression fractures of single thoracolumbar vertebrae aged60to75years old, male or female, is divided into3groups (A, B, C),n=20.We used3different treatment options:A group underwent PKP; B group underwent PKP combined with Pedicle In Vitro Restorer; C group underwent Pedicle In Vitro Restorer combined with manual reduction. We observed the volume change of the vertebral body, sagittal Cobb angle, Visual Analogue Scale (VAS),SF-36scores and the amount of cement injected bone cement leakage rate by statistical analysis after1week. Also to observe the postoperative complications including the presence or absence of vertebral collapse and pain recurrence after follow-up of mean12months.Results:(1)The study successfully measured three main factors related to the Fatigue characteristics of the biomechanical of pedicle screw fixation system:â‘ Screw strength--number of fatigue cycles (N);â‘¡the ratio of the moment between screw insertion torque and screw back-out torque(Mn);â‘¢the maximum pull-out load of the screw(T).(2)All percutaneous balloon kyphoplasty operations were completed successfully and60vertebral bodies were injected with bone cement.The blood loss is negligible.The surgery did not result in any patient death, and all patients did not have nerve root and spinal cord injury, pulmonary embolism and acute reaction of the cardiovascular system. According to the function evaluation one week after the operation,postoperative VAS scores and SF-36scores of all patients decresed obviously with a significant difference (P<0.05),postoperative and preoperative VAS score improvement group A<group B<group C.Vertebral body volume has a significant increase (P<0.05) compared with the postoperative,and the incease group C> Group B> group A.The Cobb angle has a significantly lower (P<0.05),and the reduce group C> Group B> group A.The amount of the injection of bone cement has a significant difference (P<0.05),and the amount group C> group B> group A.Group C has the lowest leakage of bone cement.All of them were followed up for average12-month.There are two cases of re-fracture in Group A and one cases in Group B,but none of the patients have neurological symptoms.None of patients in Group C have vertebral collapse or recurrence of pain.Conclusions:To the patients who suffered from Osteoporotic vertebral fractures,Pedicle In Vitro Restorer has a great Fatigue performance of the biomechanical in PKP, which can restore Physiological curvature and Mechanical strength of the spine effectively,overcome the weakness that SKY or PKP can hardly restore the Vertebral height and improve the short-term and long-term efficacy of PKP,so it is a ideal Minimally invasive surgery to treat spinal vertebral compression fractures.