奧地利科技大學研發人骨制的手術用緊固件

　　(以下節錄自ScienceDaily每日科學新聞網的專文:「Making surgical screws from bones」)

　　奧地利格拉茨科技大學的生物力學家正在研發一種使用人捐贈的骨頭制成的手術用緊固件，用來接合足部和下巴。以往數十年來，手術都是使用金屬緊固件，材質主要是鈦或不銹鋼。在手術過程中或手術之后，這些金屬緊固件會被身體視為外來的異物，時常需要再動另一次讓身體不適的外科手術來將它移除。

　　骨科醫師Klaus Pastl與格拉茨科技大學共同研發了一種稱為鯊魚緊固件(Shark Screw)的替代緊固件，以人的大腿骨制成。用人捐贈的骨頭制成的緊固件有什么優點?那就是不需再像以往要移除金屬緊固件，也不須再動二次手術，因為骨制的緊固件會與骨頭完全癒合，甚至一年之后X光機就照不到被移植進去的骨制緊固件。

　　顎骨的手術必須用到約20mm長且能承受很大應力的極小緊固件，因為下巴肌肉的體積雖小卻是人體當中力道最強的肌肉。足部手術使用的緊固件雖然比較大(4~6公分長)，卻也會遇到很大的力道，例如矯正手術中的彎折力道。

　　光是螺紋的設計就會對彎折力、剪切力和制動扭力造成很大的影響。研究人員必須調查和了解足部和下巴骨結構中的作動力?？傮w來說，使用金屬緊固件和使用生物材料制緊固件的狀況大有不同。它們的力學原理雖相同，但必須要顧慮到骨制緊固件在消毒后會稍微縮小，且會在手術結束兩小時后在體內擴張，變得更有彈性。

　　鯊魚緊固件目前是由2016年成立的奧地利新創公司Surgebright制造。這項專利的科技已在14間奧地利的醫院獲得應用。

　　Making Surgical Screws from Bones

　　(Below is an excerpt from article "Making surgical screws from bones" published on ScienceDaily)

　　Biomechanics from TU Graz, are developing surgical screws from donated human bone material for foot and jaw surgery. To heal broken bones using medical help, the surgical method of choice for decades have been metal screws, mainly made of titanium or stainless steel. During and after the healing process, these metal screws are seen by the body as disturbing foreign bodies and often have to be removed in a further unpleasant surgical intervention.

　　Together with TU Graz's Institute of Biomechanics, in 2013 orthopaedist Klaus Pastl developed an alternative: the "Shark Screw," made of the specially compact and hard middle layer of the human thigh bone (femur). So what exactly are the advantages of screws made of donated bone material? The metal doesn't have to be removed and a second operation doesn't have to be carried out because the donated material has completely healed into the bones. So well healed that the transplant is no longer visible in an x-ray after one year.

　　In maxillary surgery, extremely small screws are necessary, approximately 20 mm long, which have to withstand great stresses. Because relative to size, the jaw muscle is the most powerful muscle in the human body. In foot surgery, although the screws are bigger, between four and six centimetres long, they are also exposed to large forces, for instance bending forces in surgical corrections."

　　The design of the thread of the screws alone has an enormous effect on the bending and shear strength and breaking torque. Researchers have to investigate and understand the forces active in the bone structure of the foot and jaw. In general there is a big difference between working with metal screws and screws made of biomaterial. The mechanical principles are the same, but we also have to consider that donated bone material shrinks somewhat during sterilisation and two hours after the operation expands again in the body and becomes more elastic.

　　The Shark Screw is being produced from the start-up surgebright, which was founded in 2016. The patented technology is already being used in 14 Austrian hospitals.