TY - JOUR
T1 - A new design concept for wrist arthroplasty
AU - Shepherd, Duncan
AU - Johnstone, AJ
PY - 2005/1/1
Y1 - 2005/1/1
N2 - The wrist joint is frequently affected by arthritis, which leads to pain, loss of function and ultimately deformity. Various designs of wrist arthroplasty have been introduced to attempt to relieve pain and provide a functional range of motion. The first generation of wrist implant was a one-piece silicone elastomer. Later generations have designs that have two parts that articulate against each other. However, wrist implants have not achieved the same clinical success to date, compared with hip and knee implants, and there is a high revision rate associated with them. This paper describes a new design concept for wrist arthroplasty, based around the idea of combining the principles of an articulating implant with that of a flexible elastomer implant. The design consists of assembling a radial, carpal/metacarpal, plate and flexible parts together. The radial and carpal/metacarpal parts are to be made from ultra high molecular weight polyethylene. The bearing surfaces of the radial and carpal/metacarpal parts articulate against the flat surfaces of the plate, made from cobalt chrome molybdenum alloy. The radius on the bearing surface of the radial part enables flexion/extension, while the radius on the carpal/metacarpal surface enables radial/ulnar deviation. The articulation of the carpal/metacarpal part against the plate also allows for rotation as well as flexion/extension. The flexible part, made from Elast-Eon, which is a silicone polyurethane elastomer, is inserted through the hole of the plate and into the holes of the radial and carpal/metacarpal parts.
AB - The wrist joint is frequently affected by arthritis, which leads to pain, loss of function and ultimately deformity. Various designs of wrist arthroplasty have been introduced to attempt to relieve pain and provide a functional range of motion. The first generation of wrist implant was a one-piece silicone elastomer. Later generations have designs that have two parts that articulate against each other. However, wrist implants have not achieved the same clinical success to date, compared with hip and knee implants, and there is a high revision rate associated with them. This paper describes a new design concept for wrist arthroplasty, based around the idea of combining the principles of an articulating implant with that of a flexible elastomer implant. The design consists of assembling a radial, carpal/metacarpal, plate and flexible parts together. The radial and carpal/metacarpal parts are to be made from ultra high molecular weight polyethylene. The bearing surfaces of the radial and carpal/metacarpal parts articulate against the flat surfaces of the plate, made from cobalt chrome molybdenum alloy. The radius on the bearing surface of the radial part enables flexion/extension, while the radius on the carpal/metacarpal surface enables radial/ulnar deviation. The articulation of the carpal/metacarpal part against the plate also allows for rotation as well as flexion/extension. The flexible part, made from Elast-Eon, which is a silicone polyurethane elastomer, is inserted through the hole of the plate and into the holes of the radial and carpal/metacarpal parts.
KW - implant
KW - wrist
KW - testing
KW - design
KW - arthroplasty
UR - http://www.scopus.com/inward/record.url?scp=15944385303&partnerID=8YFLogxK
U2 - 10.1243/095441105X9219
DO - 10.1243/095441105X9219
M3 - Article
C2 - 15777056
SN - 0046-2039
VL - 219
SP - 43
EP - 52
JO - Engineering in Medicine
JF - Engineering in Medicine
ER -