Surgical treatment of severe scoliosis and kyphoscoliosis by stages / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although previous reports had reported the use of temporary internal distraction as an aid to correct severe scoliosis, two-stage surgery strategy (less invasive internal distraction followed by posterior correction and instrumentation) has never been reported in the treatment of patients with severe spinal deformity. This study aimed to report the results of the surgical treatment of severe scoliosis and kyphoscoliosis by two-stage and analyse the safety and efficacy of this surgical strategy in the treatment of severe spinal deformities.</p><p><b>METHODS</b>A total of 15 patients with severe scoliosis, kyphoscoliosis or kyphosis who underwent two-stage surgeries (less invasive internal distraction followed by posterior correction and instrumentation) were studied based on hospital records. Pretreatment radiographs and radiographs taken after first surgery (internal distraction by two small incisions), before second surgery (posterior correction, instrumentation and fusion), one week after second surgery and final follow-up were measured. Subjects were analyzed by age, gender, major coronal curve magnitude, flexibility of major curve, major sagittal curve magnitude before first surgery, after first surgery, before second surgery, after second surgery and at final follow-up. Complications related to two-stage surgeries were noted in each case.</p><p><b>RESULTS</b>The average major curve magnitude was 129.4° (range, 95° to 175°), reduced 58.9° or 45.4% after first stage surgery and reduced 30.6° or 24.6% after second stage surgery. The loss of correction during the interval between two surgeries was 7.1%. The total major coronal curve correction was 81.4° or 62.9%. At the final follow up, the average loss of correction of major coronal curve was 3.9° and the final average correction rate was 59.7%. The average major sagittal curve magnitude was 80.3° (range, 30° to 170°), and the total major sagittal curve correction was 48.2°. Loss of correction averaged 4.0° for major sagittal curve and the final correction averaged 42.2°. Clinical complications were noted in the peri-operative and long-term periods.</p><p><b>CONCLUSIONS</b>Two-stage surgery was a safe and effective surgical strategy in this difficult population. Using two-small-incision technique, the first stage surgery was less invasive. No permanent neurologic deficit was noted in this series.</p>

Analysis of neurological deficits complications in the treatment of spinal deformity with posterior spinal osteotomy / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the incidence and causes of neurologic deficits complications in the treatment of spinal deformity with posterior spinal osteotomy.</p><p><b>METHODS</b>From January 2007 to December 2010, 321 cases of scoliosis or kyphosis patients were treated with posterior spinal osteotomy. There were 124 male and 197 female with an average age of (19 ± 11) years (2 - 56 years). The average preoperative main Cobb angle was 108° ± 33° (48° - 175°), the average kyphotic angle was 74° ± 29° (53° - 170°) before operation. Pedicle subtraction osteotomy was used in 226 cases, 95 cases with vertebral column resection. Pedicle screw-rod system was used for fixation. The patients were monitored by Somatosensory-evoked potentials monitoring and Stagnara wake-up test.</p><p><b>RESULTS</b>There were 11 cases with varying degrees of new neurologic deficits and the total incidence was 3.4%. The causes were as followed, spinal translation in 2 cases, compromised by close of resected areas in 2 cases, residual bone compression in 1 case, inadvertent operation in 2 cases, screw malposition in 1 case, hematoma compression in 1 case and spine elongation in 2 cases. There was significant difference between the patients with preexisting neurologic deficits (20.0%) and the patients with intact neurologic function (2.6%) (χ(2) = 13.060, P = 0.011), no significant differences in different classes of the age, etiology, deformity, osteotomy type and surgical type (P > 0.05). But the incidence of neurologic deficits was 4.6% in congenital scoliosis, 7.1% in neuromuscular scoliosis, 5.1% in kyphosis, 5.9% in adult deformity and 5.9% in Cobb angle more than 100°, which was higher than other classes. All the 11 cases were given emergent Methylprednisolone, neurotrophic drugs and hyperbaric oxygen therapy, 4 cases were underwent surgical exploration again. After treatment, 7 cases recovered completely, 2 cases recovered partially and 2 cases failed to improve at the last follow-up.</p><p><b>CONCLUSIONS</b>Severe spinal deformity could be effectively treated with posterior spinal osteotomy. But the procedure is technical demanding and risky for neurologic deficits. The high risk factor is preexisting neurologic deficits.</p>

Balloon inflating and cement filling for treatment of avascular necrosis of the femoral head: a three-dimensional infinite-element study / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the biomechanical changes of balloon inflating and cement filling in avascular necrosis of the femoral head using finite-element analysis.</p><p><b>METHODS</b>The procedure of percutaneous balloon inflating and cement filling was simulated in fresh specimen of human femoral head. CT scan and three-dimensional reconstruction were used to establish the three-dimensional model of the femoral head. The physiological load was analyzed using three-dimensional finite element model to simulate the load and calculate stress on the hip during walking. Finite element analysis was performed on the avascular necrosis model and balloon inflating and bone cement filling model to measure the Von-Mises force at the top, neck and weight-bearing area of the femoral head. Another 8 fresh specimens of femoral head necrosis of human were obtained to stimulate balloon inflating and bone cement filling procedures, and the displacement of the femoral head under different loads was recorded before and after the procedures.</p><p><b>RESULTS</b>After bone cement filling in the necrosis area, the load reduced significantly in the weight-bearing area of the femoral head, and the load distribution became more uniform at the femoral neck and the top of the head. The anti-deformation ability of the necrosis femoral head increased after bone cement filling. The infinite-element analysis and specimen biomedical test showed similar results.</p><p><b>CONCLUSION</b>Percutaneous balloon inflating and bone cement filling in the necrosis area can change the biomechanics mechanism of the femoral head and neck, improve the supporting capacity under load, and prevent the progression of head collapse.</p>

Clinical application of posterior paramedian approach in low back surgeries / 中华外科杂志

<p><b>OBJECTIVE</b>To prospectively evaluate the clinical effects of posterior paramedian approach in nerve root decompression and reducing muscle damage in low back surgeries.</p><p><b>METHODS</b>Study group included 30 cases treated from January 2007 to May 2008, DDD 8 cases, spondylolisthesis 6 cases, LDH 11 cases, Low back surgery failure re-operation 5 cases. Based on the comprehensive understanding of modern spine anatomy, we abandoned laminectomy in our procedure, applied a mid-waist skin incision, dissect to the paraspinal muscles where you could easily reach the facets by separating between the multifidus and longissimus, enlarge the canal by performing resection along ligamentum flavum and the inner broader of the articular process, remove enough tissue till you could expose the traversing root and the disc space, this method could achieve a limited but precise and effective decompression with not taking out all of the articular process. Once the anatomy mark of the pedicle is located (usually would be at the central area of the incision), pedicle screws placement would be precise and easy without struggling with muscle traction. The following procedures would be Spondylolisthesis reduction, discectomy and interbody fusion.</p><p><b>RESULTS</b>Post-op patients of study group all showed significant improvement of pain symptoms, VAS reduced from 7.14 + or - 1.8, pre-op to 1.39 + or - 0.72 post-op, narrowed disc space regained height, spondylolisthesis reached anatomic reduction, no complications such as pedicle screw misplacement and nerve root damage were found, the lumbar spine regained it's physiological lordosis structure. Significant difference is discovered (P < 0.001) in statistic study concerning the rate of intractable low back pain between pre-op and post-op.</p><p><b>CONCLUSIONS</b>Applying low back surgery through posterior para-median approach could directly reach the inferior/superior facets and the "soft" structures of the spinal canal, expose the exact decompression region and anatomy mark of the pedicle in the central surgical field without strong retraction on the para-spinal muscles. This approach has the advantage of lowering the surgical difficulty of implantation, reducing the risk of nerve damage and is also a minimum invasive procedure. In many cases, laminectomy is unnecessary, leaving the lamina intact could preserve the physiological anatomy of the spine.</p>