Non-invasively extendable megaprosthesis

摘要 该项目是一种非侵入性延长股骨远端置换术的研制。 (DFR)适用于儿童和青少年骨肿瘤切除后。每年在 美国有200-250例股骨远端恶性骨肿瘤的诊断 患者年龄在15岁及以下。随着化疗、保肢手术的进展 使用巨型假体越来越多地成为治疗的选择。为 不断增长的患者这些巨型假体需要延长，这样它们才能像 对侧肢体生长。只有一种非侵入性延长的DFR获得FDA批准 来治疗这些病人。植入物是由一个大型电磁装置驱动的 一种临床环境。它极其复杂，平均修改率一直是 报告为48%，包括对：加长能力不足、加长 机械故障、种植体断裂、无菌性松动和感染。核磁共振是 禁忌证和植入物极其昂贵。我们的设备是非侵入性的， 通过按压病人的皮肤来手动伸展。它是为一个意义重大的 减少并发症发生率，机制简单而坚固，与MRI兼容 可以在家里加长，以获得更渐进的生长和恒定的腿长相等。 它能够提供高达其唯一美国竞争对手提供的扩展能力的240%，并且 制造更容易，成本更低，因此可以以更低的价格提供给 更多的人口。该项目的具体目标是(1)完成植入物 设计，(2)设计专门的植入手术器械和(3)进行非 为FDA提交文件做准备的临床台架测试。

ABSTRACT This project is the development of a non-invasively extending distal femur replacement (DFR) for children and adolescents subsequent to bone tumor resection. Each year in the US there are 200-250 malignant bone tumor diagnoses in the distal femurs of patients 15 years and younger. With advances in chemotherapy, limb salvage surgery utilizing a megaprosthesis has increasingly become the treatment of choice. For growing patients these megaprostheses are required to extend so they can “grow” as the contralateral limb grows. Only one non-invasively lengthened DFR is FDA approved to treat these patients. The implant is actuated with a large electromagnetic appliance in a clinical setting. It is exceedingly complex and the average revision rate has been reported at 48%, including revisions for: insufficient lengthening capacity, lengthening mechanism failure, implant fracture, aseptic loosening and infection. MRI is contraindicated and the implant is extremely expensive. Our device is non-invasively, manually extended by pressing on the patient's skin. It's designed for a significantly reduced complication rate, the mechanism is simple and robust, it's MRI compatible and can be lengthened at home for a more gradual growth and constant leg length equality. It is capable of up to 240% of the extension that its sole US competitor offers and is easier and less expensive to manufacture so it can be offered at a reduced price to a greater population. The specific aims of the project are to (1) complete the implant design, (2) design specialized surgical instruments for implantation and (3) conduct non- clinical bench testing in preparation for FDA submission.