In vivo biomechanical study of cervical spine kinematics / 医用生物力学

The traditional method of in vitro biomechanical study cannot simulate the realistic environment in human body due to the limitation of in vitro technology. Using advanced imaging techniques and testing methods, in vivo biomechanical studies of cervical spine kinematics can directly observe the cervical spine motion of living subjects. The data obtain repeats physiological situations and has important implications for improvement in clinical practice. In this paper, the biomechanical research methods of cervical spine kinematics, as well as the development process and current status were reviewed. The postoperative changes in cervical spine kinematics and the effects on adjacent segments following cervical spine fusion and cervical disc arthroplasty surgery were analyzed. The future developments in cervical spine research were also discussed.

Selectivity and individualization of transpedicular balloon kyphoplasty for aged osteoporotic spinal fractures / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the selectivity and individualization of transpedicular balloon kyphoplasty for aged osteoporotic spinal fracture.</p><p><b>METHODS</b>Twenty-two consecutive procedures were performed in 17 aged patients with osteoporotic spinal compression fractures from April 2002 to June 2004. The signal changes in different sequences were confirmed by magnetic resonance imaging before the procedures. This operation involved the percutaneous insertion of two inflatable bone tamps into a fractured vertebral body transpedicularly under fluoroscopic guidance. Every patient was treated individually, according to the results of radiography and CT scan before operation. Preoperative and postoperative complications, visual analogue scale, and radiographic findings such as vertebral height and Cobb angle were recorded and analyzed.</p><p><b>RESULTS</b>All patients tolerated the procedure well with immediate relief of their back pain in 24 hours. There was no leakage of cement into the epidura. The mean loss percent of the anterior and middle vertebral heights were (35.32 +/- 13.15)% and (27.53 +/- 12.61)% before operation, and (14.21 +/- 12.43)% and (16.2 +/- 7.5)% after operation. The height restoration of vertebra was confirmed by X-ray after the procedure (P < 0.01). The mean kyphosis was improved from (25.3 +/- 4.2) degrees to (8.6 +/- 5.1) degrees. No complications occurred. No patient had nerve injury. The patients were allowed to walk next day after the procedure.</p><p><b>CONCLUSION</b>The selectivity and individualization of transpedicular balloon kyphoplasty for aged osteoporotic spinal fractures has satisfactory short-term clinical efficacy. It is also an effective way to prevent complications.</p>

The contrast study between single and double balloon bilateral dilatation of kyphoplasty / 中华外科杂志

<p><b>OBJECTIVE</b>To contrast single and double balloon-inflated kyphoplasty for vertebral compression fractures (VCFs) and evaluate its clinical efficacy.</p><p><b>METHODS</b>From May 2000 to May 2004, 90 consecutive procedures were performed in 58 patients who suffered from painful vertebral compression fractures, transferring tumour and angioma. Ninety vertebrae were inflated while 62 as A group were double balloon and 28 as B group were single balloon, fracture reduction and bone cement augmentation. Preoperative and postoperative symptom levels, variables, complications were recorded and the vertebral height and Cobb angle were measured and analyzed.</p><p><b>RESULTS</b>All patients' pain was alleviated or disappeared without syndrome, and the vertebral height and Cobb angle of both groups were improved. The average recovery rate was 72.6% (22.9% approximately 100%), Cobb angle from 17.9 degrees (3.1 degrees approximately 31.6 degrees ) were corrected to 9.6 degrees (0.6 degrees approximately 28.2 degrees ), the average angle was 8.7 degrees (0.3 degrees approximately 27.2 degrees ), and the contrast between preoperative and postoperative showed obvious differences (P <0.001). The average recovery rate of A group was 77.6% (55.3% approximately 100%), B group was 64.3% (22.9% approximately 100%). The average postoperative Cobb angle of A group was 9.9 degrees (0.3 degrees approximately 27.2 degrees ), B group was 8.6 degrees (0.6 degrees approximately 19.8 degrees ) (P >0.05).</p><p><b>CONCLUSIONS</b>As a promising minimally invasive surgery, balloon kyphoplasty can provide early relief of pain and improve the function as well as spinal alignment in treatment of painful compression fracture owing to recovering the vertebral height and Cobb angle of the vertebral body. Single balloon-inflated kyphoplasty can improve VCFs as double balloon.</p>