Panda Nirmal, Krishnamurty Balasubramanian, Agarwal Manish, Ravi Bhallamudi
1Non-Ferrous Materials Technology Development Centre, Hyderabad, India.
2P.D. Hinduja Hospital and Medical Research Centre, Mumbai, India.
Indian J Orthop. 2020 Jan 24;54(2):130-140. doi: 10.1007/s43465-019-00033-1. eCollection 2020 Apr.
Mega-prostheses required for reconstructing large gaps in bone after limb-saving surgeries for osteo-sarcoma patients have a long development cycle. This includes design of prosthesis components and surgical armamentarium, followed by pilot batch production, lab testing, human clinical trials and regulatory approvals. Most manufacturers stay away due to small market size coupled with the difficulties and high costs involved. Prostheses developed in the West are often unsuitable and unaffordable for the majority of Indian patients. There is a need for high-quality yet low-cost prostheses that are compatible with the anatomy and functionality of local population.
An inter-disciplinary group comprising orthopedic oncologists, mechanical engineers and materials scientists from three different organizations in India took up the above challenge. They developed a novel modular tumour knee prosthesis with rotating hinge, as well as surgical armamentarium with femoral and tibial cutting jigs and other instruments. Knee simulator and testing machines were developed to test the prosthesis. A dedicated pilot production facility along with inspection and quality management system was set up.
The new prosthesis provides flexion-extension up to 120 degrees and axial rotation of ±5 degrees. It successfully completed ten million cycles of fatigue and wear testing. The regulatory body of the government and institutional ethical committees of hospitals approved the human clinical trials, which are currently in progress.
The design, manufacturing and testing of the prosthesis components and armamentarium took more than a decade and presented many challenges. These were overcome by several technological innovations by the engineering team and continuous feedback from the surgeons. The experience is expected to be useful to all others interested in this field.
骨肉瘤患者保肢手术后重建骨骼大缺损所需的大型假体开发周期很长。这包括假体组件和手术器械的设计，随后是试生产、实验室测试、人体临床试验和监管批准。由于市场规模小以及相关的困难和高成本，大多数制造商都望而却步。西方开发的假体通常不适用于大多数印度患者，且价格昂贵。需要高质量且低成本、与当地人群的解剖结构和功能相匹配的假体。
来自印度三个不同机构的骨科肿瘤学家、机械工程师和材料科学家组成的跨学科团队接受了上述挑战。他们开发了一种新型的带旋转铰链的模块化肿瘤膝关节假体，以及带有股骨和胫骨截骨导向器及其他器械的手术器械。开发了膝关节模拟器和测试机器来测试假体。建立了一个专门的试生产设施以及检验和质量管理系统。
新假体的屈伸角度可达120度，轴向旋转角度为±5度。它成功完成了一千万次疲劳和磨损测试。政府监管机构和医院的机构伦理委员会批准了目前正在进行的人体临床试验。
假体组件和器械的设计、制造和测试耗时十多年，面临诸多挑战。工程团队通过多项技术创新以及外科医生的持续反馈克服了这些挑战。预计该经验对该领域的所有其他感兴趣者都有用。
