Comparative study of Kurokawa's double door laminoplasty and modified Kurokawa's double door laminoplasty for the treatment of cervical disorders / 中华外科杂志

<p><b>OBJECTIVE</b>To observe and compare the medium-long-term efficacy of Kurokawa's and modified Kurokawa's double door laminoplasty for the treatment of cervical disorders.</p><p><b>METHODS</b>A retrospective analysis was performed to compare the outcomes and complications between two kinds of operations on 172 cases from January 2002 to December 2010, including 106 cases of cervical spondylotic myelopathy, 52 cases of cervical stenosis, 21 cases of cervical ossification of the posterior longitudinal ligament. Patients were divided into two groups according to two surgical methods: traditional group, including 51 male and 18 female patients, with mean age of (56 ± 18) years (35-76 years); modified group, including 75 male and 28 female patients, with mean age of (58 ± 20)years (35-80 years). The two groups were comparable and compared according to different data using t test, χ(2) test and rank sum test.</p><p><b>RESULTS</b>All patients were followed up continuously for (52 ± 33)months, 123 patients were followed up ≥ 2 years, 71 patients ≥ 5 years. All patients' Japanese Orthopaedic Association (JOA) score improved significantly at the latest follow-up(t = 3.420, P < 0.01); no significant difference between the patients' JOA score improvement rate of two groups. The postoperative incidence rate of axial symptoms in patients of modified group (3.9%) was significantly lower than the traditional group (14.5%) (χ(2) = 7.548, P < 0.05), and cervical intervertebral activity decreased in the modified group was better than the traditional group in the first 3 months postoperatively (27% ± 6% vs. 19% ± 4%,Z = 6.34, P < 0.05), but during the medium-long-term follow-up, no significant difference in the cervical intervertebral activity decreased between two groups.</p><p><b>CONCLUSIONS</b>Medium-long-term efficacy of Kurokawa's and modified Kurokawa's double door laminoplasty is satisfied and reliable. Avoiding damaging of semispinalis cervicis insertion in spinous process of C2, the modified operation method can protect the extensor group of the neck muscle and reduce the incidence of postoperative axial symptoms better.</p>

Two kinds of posterior approach for Kvmmell's disease after osteoporotic thoracolumbar fracture / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To compare the surgical results of two kinds of posterior approach for osteoporotic thoracolumbar Kvmmell's disease.</p><p><b>METHODS</b>Clinical and radiographic results of 1-segmental pedicle screw fixation combined with vertebroplasty (Group A, n equal to 12) or posterior shortening osteotomy (Group B, n equal to 16) for osteoporotic thoracolumbar Kvmmell's disease were analyzed retrospectively. Japanese orthopedic association (JOA) and visual analogue scale (VAS) scores were used for clinical evaluation. Neurological status was judged by Frankel grades. X-ray was used to evaluate the radiographic results. Complications related to operation and devices were also considered.</p><p><b>RESULTS</b>The follow-up period was 12-54 months (average 29 months). Pre-and post-operative VAS were 9.3 and 3.2 in Group A, 8.9 and 2.5 in Group B, respectively. The mean JOA score at the final follow-up was significantly higher than that of pre-operation (t equal to 5.306, P less than 0.001). There was no significant difference between Groups A and B (t equal to 0.618, P larger than 0.05). The kyphosis were corrected from preoperative 33.9 degree A)/37.3 degree B) to postoperative 10.3 degree A)/6.5 degree B), and 15.3 degree (A)/13.7 degree B) at the final follow-up. There was a significant difference between the two groups at the final follow-up. Frankel grade was improved from grade C preoperatively to postoperatively grade D or E in 7 cases of Group A and 5 cases of Group B, from grade D to E in 5 cases of Group A and 11 cases of Group B. The mean improvement was 1.6 and 1.7 grades for Groups A and B, respectively. There were no serious complications related to internal fixation.</p><p><b>CONCLUSIONS</b>The similar clinical results can be obtained by the two kinds of posterior surgical methods for osteoporotic Kvmmell's disease. Posterior spinal shortening is a better choice for patients with serious kyphosis combined with neurological deficit than the other.</p>

Biomechanical comparison of two types of posterior pedicle instrumentation / 中华创伤骨科杂志

Objective To compare the biomechanical properties between the two-level fixation by im- plantation of pedicle-screws into the adjacent upper and lower vertebrae of the fractured vertebra and the three-level fixation by implantation of pedicle screws into the fractured vertebra and its adjacent upper and lower vertebrae in the treatment of thoracolumbar burst fractures.Methods Eight fresh frozen calf spines were used in this study.Each specimen was tested in four models:intact model as the control,L1 burst fracture model,two-level fixation model, and three-level fixation model.The L1 burst fracture model was created on a biaxial material testing machine (MTS858 Bionix test system,America).During the experiment,the flexion,extension,bilateral bending and axial rotation loadings were applied to the specimens and the range of motion(ROM)was measured with a three-dimensional laser analysis apparatus and the stiffness was calculated subsequently.One-way statistical analysis was used.Results The ROMs under six different loadings in the fracture model became larger obviously(P＜0.05)and the stiffness decreased(P＜0.05).The ROMs in both fixation models were smaller than those in the other models(P＜0.01)and the stiffness increased distinctly(P＜0.05).There were no significant differences in ROMs and stiffness between the two-level fixation and three-level fixation models(P＞0.05).Conclusion Two-level fixation provides similar biomechanical stability as three-level fixation does in the reconstruction of unstable thoracolumbar fractures.