l**1
发帖数: 1875 | 1 【 以下文字转载自 Medicalpractice 讨论区 】
发信人: Aplusplus (Hakuna Matata), 信区: Medicalpractice
标 题: 今天终于明白什么是“You are screwed”
发信站: BBS 未名空间站 (Fri Oct 26 21:50:58 2012, 美东)
一年前看一个腰疼病人，常年累月受腰疼折磨，我给他照了张片子，发现有很多金属的
影像，他说十几年前交通事故，把腰给弄折了，做了手术， 腰疼从此开始。 我对他说
，找骨科医生看一下，可能需要再手术。
今天他回来了，告诉我他做了手术，腰现在基本不疼了， 同时他给了我看一个塑料袋
，我纳闷，什么意思？ 买这些螺丝搞装修啊？
他说：骨科医生给他的，都是从他腰椎上取下的。
我说： You were really screwed.
LOL | c******k
发帖数: 8998 | | w********h
发帖数: 12367 | 3 it is impossible...they look very new...
【在 l**1 的大作中提到】
: 【 以下文字转载自 Medicalpractice 讨论区 】
: 发信人: Aplusplus (Hakuna Matata), 信区: Medicalpractice
: 标 题: 今天终于明白什么是“You are screwed”
: 发信站: BBS 未名空间站 (Fri Oct 26 21:50:58 2012, 美东)
: 一年前看一个腰疼病人，常年累月受腰疼折磨，我给他照了张片子，发现有很多金属的
: 影像，他说十几年前交通事故，把腰给弄折了，做了手术， 腰疼从此开始。 我对他说
: ，找骨科医生看一下，可能需要再手术。
: 今天他回来了，告诉我他做了手术，腰现在基本不疼了， 同时他给了我看一个塑料袋
: ，我纳闷，什么意思？ 买这些螺丝搞装修啊？
: 他说：骨科医生给他的，都是从他腰椎上取下的。
| s********r
发帖数: 2308 | | O*******d
发帖数: 20343 | | n***d
发帖数: 8857 | 6 10几年前就普及钛合金了？
【在 O*******d 的大作中提到】
: 人体内只用钛合金的。 没有用黄铜的和阳极铝的。
| l*****e
发帖数: 16384 | | I****9
发帖数: 5245 | 8
不锈钢发来贺电
【在 O*******d 的大作中提到】
: 人体内只用钛合金的。 没有用黄铜的和阳极铝的。
| l**1
发帖数: 1875 | 9 【 以下文字转载自 Medicalpractice 讨论区 】
发信人: Aplusplus (Hakuna Matata), 信区: Medicalpractice
标 题: 今天终于明白什么是“You are screwed”
发信站: BBS 未名空间站 (Fri Oct 26 21:50:58 2012, 美东)
一年前看一个腰疼病人，常年累月受腰疼折磨，我给他照了张片子，发现有很多金属的
影像，他说十几年前交通事故，把腰给弄折了，做了手术， 腰疼从此开始。 我对他说
，找骨科医生看一下，可能需要再手术。
今天他回来了，告诉我他做了手术，腰现在基本不疼了， 同时他给了我看一个塑料袋
，我纳闷，什么意思？ 买这些螺丝搞装修啊？
他说：骨科医生给他的，都是从他腰椎上取下的。
我说： You were really screwed.
LOL | c******k
发帖数: 8998 | | | | w********h
发帖数: 12367 | 11 it is impossible...they look very new...
【在 l**1 的大作中提到】
: 【 以下文字转载自 Medicalpractice 讨论区 】
: 发信人: Aplusplus (Hakuna Matata), 信区: Medicalpractice
: 标 题: 今天终于明白什么是“You are screwed”
: 发信站: BBS 未名空间站 (Fri Oct 26 21:50:58 2012, 美东)
: 一年前看一个腰疼病人，常年累月受腰疼折磨，我给他照了张片子，发现有很多金属的
: 影像，他说十几年前交通事故，把腰给弄折了，做了手术， 腰疼从此开始。 我对他说
: ，找骨科医生看一下，可能需要再手术。
: 今天他回来了，告诉我他做了手术，腰现在基本不疼了， 同时他给了我看一个塑料袋
: ，我纳闷，什么意思？ 买这些螺丝搞装修啊？
: 他说：骨科医生给他的，都是从他腰椎上取下的。
| s********r
发帖数: 2308 | | O*******d
发帖数: 20343 | 13 人体内只用钛合金的。 没有用黄铜的和阳极铝的。 | n***d
发帖数: 8857 | 14 10几年前就普及钛合金了？
【在 O*******d 的大作中提到】
: 人体内只用钛合金的。 没有用黄铜的和阳极铝的。
| l*****e
发帖数: 16384 | | I****9
发帖数: 5245 | 16
不锈钢发来贺电
【在 O*******d 的大作中提到】
: 人体内只用钛合金的。 没有用黄铜的和阳极铝的。
| O*******d
发帖数: 20343 | 17 铜和阳极铝根本不在考虑之列。
Despite the great numbers of metals and alloys known to man, remarkably few
warrant even preliminary consideration for uses as implant materials. The
relatively corrosive environment combined with the poor tolerance of the
body to even minute concentrations of most metallic corrosion products
eliminates from discussion most metallic materials. Of the possible metallic
candidates, tantalum and the noble metals do not have suitable mechanical
properties for the construction of most orthopedic tools and implants, while
zirconium is in general too expensive:
Stainless Steels
The austentic stainless steels, especially Types 316 and 316L, are most
widely used for implant fabrication. Stainless steel that has a low content
of impurities and a passivated finish is entirely suitable for implantation
in the human body. Forged stainless steel has a greater yield strength than
cast stainless steels, but has a lower fatigue strength than other implant
alloys. However, stainless steel is more ductile and more easily machined,
and recent advancements have significantly enhanced its properties. Because
a femoral component fracture with early designs, stainless steel is no
longer used routinely, from the standpoint of erosion, biocompatability, and
fatigue life, stainless steel is inferior to other super alloys.
The only difference in composition between 316L and 316 stainless steel is
the content of carbon. A wide range of properties exists depending on the
heat treatment (annealing to obtain softer materials) or cold working (for
greater strength and hardness). Even the 316L stainless steels may corrode
inside the body under certain circumstances in a highly stressed and oxygen
depleted region, such as contact under screws or fracture plates. Thus,
stainless steels are suitable to use only in temporary implant devices, such
as fractures plates, screws and hip nails.
New nickel-free stainless steels have been recently developed primarily to
address the issue of nickel sensitivity. These stainless steels also have
superior mechanical properties and better corrosion resistance. The Ni-free
compositions appear to possess an extraordinary combination of attributes
for potential implant applications in the future.
Cobalt Chrome Alloys
There are basically two types of cobalt chromium alloys. One is the cobalt
CoCrMo alloy, which is usually used to cast a product and the other is the
CoNiCrMo alloy, which is usually wrought by (hot) forging. The castable
CoCrMo alloy has been used for many decades in dentistry and recently, in
making artificial joints. The wrought CoNiCrMo alloy is a relative newcomer
now used for making the stems of prosthesis for heavily loaded joints such
as the knee and hip. Cobalt-based alloys are highly resistant to corrosion
and especially to attack by chloride within crevice. As in all highly
alloyed metals in the body environment, galvanic corrosion can occur, but to
a lesser extent than in the iron-based alloys.
Cobalt-based alloys are quite resistant to fatigue and to cracking caused by
corrosion, and they are not brittle, since they have a minimum of 8%
elongation. However, as is true of other alloys, cobalt based alloys may
fail because of fatigue fracture (but less often than stainless steel stems)
. The abrasive wear properties of the wrought CoNiCrMo alloy are similar to
the cast CoCrMo alloy. The superior fatigue and ultimate tensile strength of
the wrought CoNiCrMo alloy make it suitable for the applications which
require long service without fracture or stress fatigue. Such is the case
for the stems of the hip joint prosthesis. Both the cast and wrought alloys
have excellent corrosion resistance. The modulus of elasticity for the CrCo
alloys does not change with the changes in their ultimate tensile strength.
The values are higher than other materials such as stainless steels. This
may have some implications of different load transfer modes to the bone in
artificial joint replacements, although the effect of the increased modulus
on the fixation and longevity of the implants is not clear.
Titanium and Titanium-Based Alloys
Attempts to use titanium for implant fabrication dates to the late 1930's.
It was found that titanium was tolerated in cat femurs, as was stainless
steel and vitalium (a CoCrMo alloy). Titanium's lightness and good
mechanical and chemical properties are salient features for implant
applications. One titanium alloy (Ti6Al4V) is widely used to manufacture
implants. The main alloying elements of the alloy are aluminium (5.5 - 6.5%)
and vanadium (3.5 - 4.5%). Whilst the strength of the titanium alloys
varies from lower than to equal to that of 316 stainless steel, when
compared by specific strength (strength per density), the titanium alloys
outperform any other implant material. Titanium nevertheless, has poor shear
strength, making it less desirable for bone screws, plates and similar
applications.
Titanium also tends to seize when in sliding contact with itself or other
metal. Titanium-based alloys that have a high co-efficient of friction which
can cause problems. Wear particles are formed in a piece of bone if a piece
of bone rubs against the implant, or if two parts of an implant rub against
one another. Therefore, implants of titanium upon titanium generally are
not used as joint surfaces. Titanium derives its corrosion resistance to the
formation of a surface oxide film. Under 'in vivo' conditions, the oxide is
the only stable reaction product.
http://events.nace.org/library/corrosion/Implants/Metals.asp
【在 n***d 的大作中提到】
: 10几年前就普及钛合金了？
| b***y
发帖数: 215 | 18 Look like my company's M-8 screw and rod system |
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