Friday, June 25, 2010

recent advances in bearing surfaces of total hip arthroplasty

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Recent advances in bearing surfaces of total hip arthroplasty

Postby viru somahekaraiah » Sun Jun 13, 2010 10:20 pm 

1. polyethelene----10 m rad gamma radiation---- annealing at 150* c. ----- results in highly crossed linked polyethelene --- which has very low wear rate
so head size can be increased, thus helping in surface replacement arthroplasty also.

2. metal on metal--- investment casting on high carbon cobalt chromium alloy--- -- precipitation of high carbide larger particles all over the matrix .

carbide is very hard approximatly = ceramic , resistant to wear, less debris, less risk of loosening.
3. ceramic on ceramic- hot isostatic pressing 3 fold reduction in particle size---- improved burst strength.

proof testing of individual implant.
reference- cambell.

thanks to hitesh and harshad for sending me ppt of damage control orthopaedics, that helped me a lot.

 viru somahekaraiah

See details

Orthopaedic Principles

other links :

Bearing Surfaces in Hip Arthroplasty (pdf)

 Alternative bearing surfaces in total hip arthroplasty - ncbi

Alternative bearing surfaces for total joint arthroplasty - JAAOS


 

Thursday, June 24, 2010

SCHEUERMANN’S KYPHOSIS

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SCHEUERMANN’S KYPHOSIS

 Hitesh Gopalan U, Senthilnathan T, Ramesh Dalwai, Shamsul Hoda
Introduction
Scheuermann disease is a structural kyphosis of the thoracic or thoracolumbar spine, of unknown aetiology, is characterized by vertebral body wedging, thoracic kyphosis of > 40° & > 5° of anterior wedging of 3 consecutive adjacent vertebral bodies at the apex of the kyphosis, having presence of Schmorl’s nodes, irregular endplates, and a narrowing of verterbral disc space, and increased verterbral anterior/posterior diameter at the apex.
see full article at:
http://orthopaedicprinciples.com/2010/06/493/