Lorenz Heiko M, Braunschweig Lena, Badwan Batoul, Groenefeld Katharina, Hecker Marina M, Tsaknakis Konstantinos, Grote Jasmin, Hell Anna K
Department of Trauma, Orthopaedic and Plastic Surgery, University Medical Center Goettingen, Goettingen, Germany.
J Pediatr Orthop. 2019 May/Jun;39(5):e334-e338. doi: 10.1097/BPO.0000000000001303.
Magnetically controlled implant systems have been established to treat severe progressive spinal deformity in children. The purpose of this study was to evaluate (1) the ratio between achieved and expected distraction length, (2) the complication rate and its risk factors as well as (3) the correlation of the distraction length and the length of the spine.
A total of 40 patients with an average follow-up of 34 (14 to 57) months were prospectively included in the study. Children underwent lengthening procedures every three months. The ratio between the distraction lengths was determined by comparing the measured distraction length of the rod on radiographs with the distraction length displayed on the external remote controller for the magnetically controlled growing rod (MCGR). Age, weight, height, and complications were repeatedly recorded.
The analysis of 746 procedures showed the actual distraction to be 94.4% of the expected one. No difference between implants on the concave and convex spinal side was observed. The overall complication rate was 4.6% mainly because of failure of the implant or lack of implant extension, which was directly related to an increased BMI. There was also a strong correlation between achieved implant distraction length and gain in spinal length.
Our study demonstrates a high ratio (0.94) between achieved and expected distraction length of magnetically controlled spinal rods. The complication rate was low (4.6%) and correlated to a high BMI. The correlation between the achieved implant distraction length and spinal length indicates the efficiency of the MCGR therapy.
Therapeutic Level IV.
磁控植入系统已被用于治疗儿童严重的进行性脊柱畸形。本研究的目的是评估：（1）实际获得的撑开长度与预期撑开长度的比例；（2）并发症发生率及其危险因素；以及（3）撑开长度与脊柱长度的相关性。
本研究前瞻性纳入了40例患者，平均随访34（14至57）个月。患儿每三个月接受一次延长手术。通过将X线片上测量的棒的撑开长度与磁控生长棒（MCGR）外部遥控器上显示的撑开长度进行比较，确定撑开长度的比例。反复记录年龄、体重、身高和并发症情况。
对746次手术的分析显示，实际撑开长度为预期撑开长度的94.4%。在脊柱凹侧和凸侧的植入物之间未观察到差异。总体并发症发生率为4.6%，主要原因是植入物失效或缺乏植入物延长，这与BMI增加直接相关。获得的植入物撑开长度与脊柱长度增加之间也存在很强的相关性。
我们的研究表明，磁控脊柱棒实际获得的撑开长度与预期撑开长度之间的比例很高（0.94）。并发症发生率较低（4.6%），且与高BMI相关。获得的植入物撑开长度与脊柱长度之间的相关性表明了MCGR治疗的有效性。
治疗性四级。
