الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 71 |  |  |
| | | from | 71 | | |
Abstract
The common causes of knee pain and loss of knee function in clinic are O.A., R.A. and post traumatic arthritis. (Bhan et al., 2002).
Sometimes O.A. only affects one side of the joint, and it may be better to replace just this side which called unicopartmental replacment. However, if there is a risk that the arthritis may become more generalised in the joint, the surgeon may decide to perform a total rather than unicopartmental replacment. (Naal et al., 2007).
The choice of the designers can go either towards a constrained prosthesis less physiological, more stable, but presenting the disadvantage of transmitting most of the stress to the bone by the intermediary of the prosthetic pieces at the anchoring point thus encouraging loosening or towards a prosthesis less constrained in which the stability is assured by the ligamentary apparatus, preserved to a maximum, but with the risk of instability if this ligamentary system is not perfectly balanced or deteriorates secondarily. (Insall and Clarke et al., 2001).
Whether the PCL is salvaged or sacrificed has been much debated. (Maruyama et al., 2004).
Mobile-bearing implants were also developed with the aim of increasing articular conformity throughout flexion. A concern with these designs is their potential for instability created by greater movement of the insert. (Lu et al., 2010).
Today, most knee replacments are still cemented. Femoral fixation has been durable without cement and ’hybrid’ fixation has lasted well. The perceived advantages of cementless designs are speed, fewer interfaces for loosening, and easier revision with protection of bone stock. (Gandhi, 2009).
Whether to resurface the patella remains an important question. Patellar resurfacing does not guarantee a painless patellofemoral joint. (Pakos et al., 2005).
Continued refinement of instrumentation, surgical technique should result in more predictable outcomes, so it is likely that minimally invasive surgery will become a standard techniquefor knee replacment. (Cheng et al., 2010).
Although computer-assisted surgery offers improvement in implant alignment, the current barriers of increased surgical time, cost, and training limit its application. (Sto¨ckl et al, 2004).
Revision total knee replacment is done to alleviate pain and improve function. Results are not as good as with primary total knee replacment. Failed revisions require a salvage procedure with inferior results compared with revision total knee replacment.
(Sharkey et al., 2002).