Department of Orthopedic Surgery, University of Toledo College of Medicine, Toledo, OH.
Department of Statistics, University of Kentucky.
J Pediatr Orthop. 2022;42(5):e435-e440. doi: 10.1097/BPO.0000000000002103.
Tension band plate and screw implants (TBI) are frequently used for temporary hemiepiphyseodeses to manage angular deformity in growing children. The reported implant breakage rate, when TBI is used for deformities in patients with Blount disease, is much higher than when used in other diagnoses. Our hypothesis is that perioperative factors can identify risks for TBI breakage.
A retrospective case-control study was performed of 246 TBI procedures in 113 patients with Blount disease at 8 tertiary pediatric orthopaedic centers from 2008 to 2018. Patient demographics, age at diagnosis, weight, body mass index (BMI), radiographic deformity severity measures, location, and types of implants were studied. The outcome of implant breakage was compared with these perioperative factors using univariate logistic regression with Bonferroni correction for multiplicity to significance tests.
There were 30 broken implants (12%), failing at mean 1.6 years following implantation. Most failures involved the metaphyseal screws. Increased BMI was associated with increased implant breakage. Increased varus deformity was directly associated with greater implant breakage and may be a more important factor in failure for those below 7 years compared with those 8 years or above at diagnosis. There was a 50% breakage rate for TBI with solid 3.5 mm screws in Blount disease with onset 8 years or above of age. No demographic or implant factors were found to be significant.
Breakage of TBI was associated with increased BMI and varus deformity in patients with Blount disease. Larger studies are required to determine the relative contribution and limits of each parameter. Solid 3.5 mm screws should be used with caution in TBI for late-onset Blount disease.
Level III.
张力带钢板和螺钉植入物（TBI）常用于临时半骺切除术以矫正儿童生长期的角度畸形。当 TBI 用于治疗 Blount 病患者的畸形时，报告的植入物断裂率远高于用于其他诊断时。我们的假设是围手术期因素可以确定 TBI 断裂的风险。
对 2008 年至 2018 年期间，8 家三级儿科骨科中心的 113 名 Blount 病患者的 246 例 TBI 手术进行了回顾性病例对照研究。研究了患者的人口统计学资料、诊断时的年龄、体重、体重指数（BMI）、放射学畸形严重程度测量、植入物的位置和类型。使用单变量逻辑回归并进行多重性校正对显著性检验，比较了植入物断裂的结果与这些围手术期因素。
有 30 个植入物（12%）断裂，在植入后平均 1.6 年失败。大多数失败涉及骺板螺钉。BMI 增加与植入物断裂增加有关。内翻畸形越大，与更大的植入物断裂直接相关，并且在诊断年龄为 8 岁或以上的患者中，与诊断年龄为 8 岁以下的患者相比，可能是失败的更重要因素。8 岁或以上起病的 Blount 病患者中，使用 3.5mm 实心螺钉的 TBI 断裂率为 50%。未发现任何人口统计学或植入物因素有统计学意义。
在 Blount 病患者中，TBI 的断裂与 BMI 增加和内翻畸形有关。需要更大的研究来确定每个参数的相对贡献和限制。对于晚期发病的 Blount 病，应谨慎使用实心 3.5mm 螺钉进行 TBI。
III 级。
