Meza Blake C, Shah Suken A, Vitale Michael G, Sturm Peter F, Luhmann Scott J, Anari Jason B
Department of Orthopaedic Surgery, The Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA, 19104, USA.
Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.
Spine Deform. 2020 Aug;8(4):793-800. doi: 10.1007/s43390-020-00102-8. Epub 2020 Mar 18.
Multicenter, retrospective cohort study.
Analyze the impact of MCGR proximal anchor location and density on radiographic outcomes and complications. Magnetically controlled growing rods (MCGRs) reduce the need for repeat operations for lengthening when treating spinal deformity in children. The evidence behind choosing the location and density of proximal anchors comes from the traditional growing rod and rib-based distraction technique literature. Thus, there is much debate regarding the optimal quantity and location of proximal anchors.
This study included early-onset scoliosis patients treated with MCGR with a minimum 2-year follow-up. Comparisons of 2-year correction in the coronal and sagittal planes, complication rates, and patient-reported outcomes were made based on proximal fixation type, proximal anchor density, and type of case (primary, conversion).
This study included 155 MCGR patients. Spinal deformity correction at 2 years was significantly higher in spine-based than rib-based constructs, in terms of both the major (23.9° vs. 17.1°, p = 0.05) and minor curves (10.0° vs. 4.5°, p = 0.03). Greater proximal anchor density, regardless of location, was also associated with better major curve correction at 2 years (25.0° vs. 18.2°, p < 0.05). There was a trend towards higher risk of device migration with rib-based fixation (13.8% vs. 4.1%, p = 0.06) and rod breakage with spine-based fixation (10.3% vs. 3.4%, p = 0.21). Having 5+ proximal anchors did not significantly decrease the risk of complication, including device migration (8.4% vs. 7.7%).
When using the MCGR, proximal spine anchors and greater anchor density impart superior deformity correction but do not significantly impact the risk of device complications. Although rib-based constructs afford less rigidity than spine-based constructs, there is a similar risk of rod breakage and device migration. This study suggests that having 5+ MCGR proximal anchors does not protect against proximal anchor complication.
Level III-therapeutic.
多中心回顾性队列研究。
分析磁控生长棒（MCGR）近端锚定位置和密度对影像学结果及并发症的影响。磁控生长棒在治疗儿童脊柱畸形时减少了重复延长手术的需求。选择近端锚定位置和密度的依据来自传统生长棒及基于肋骨撑开技术的文献。因此，关于近端锚定的最佳数量和位置存在诸多争议。
本研究纳入接受MCGR治疗且随访至少2年的早发性脊柱侧凸患者。基于近端固定类型、近端锚定密度及病例类型（原发性、转换型），对冠状面和矢状面的2年矫正情况、并发症发生率及患者报告的结果进行比较。
本研究纳入155例MCGR患者。在2年时，基于脊柱的结构在脊柱畸形矫正方面显著优于基于肋骨的结构，无论是主弯（23.9°对17.1°，p = 0.05）还是次弯（10.0°对4.5°，p = 0.03）。无论位置如何，更高的近端锚定密度也与2年时更好的主弯矫正相关（25.0°对18.2°，p < 0.05）。基于肋骨固定时器械移位风险有升高趋势（13.8%对4.1%，p = 0.06），基于脊柱固定时棒体断裂风险有升高趋势（10.3%对3.4%，p = 0.21）。有5个及以上近端锚定并不能显著降低并发症风险，包括器械移位（8.4%对7.7%）。
使用MCGR时，近端脊柱锚定和更高的锚定密度能实现更好的畸形矫正，但对器械并发症风险无显著影响。尽管基于肋骨的结构比基于脊柱的结构刚性小，但棒体断裂和器械移位风险相似。本研究表明，有5个及以上MCGR近端锚定并不能预防近端锚定并发症。
治疗性III级。
