TKR (Total Knee Replacement)
	It is an old idea to put a foreign body (Prosthesis) between the damaged bones which form the knee joint. The results of this operation were not encouraging due to the complexity of the knee joint, which consists of six articulatory surfaces that are all shallow; i.e. they lack fixation. However , the developments of the biomedical research have led to complete changes in the results of the TKR in relation to quality & longevity of the artificial joint ( ranging between 12-20 years ). All these factors contribute to the modification of effectiveness & facilitating the post-operative stage.
	When is TKR needed?
	When severe oeteoarthritis (wearing of cartilage), which cushion the articulatory surfaces of the knee, lead to inflammation and swelling in the joint together with severe pain. The progressive arthritis and wearing of the cartilage cause bowing with increased click in the joint, which limits their mobility & causing more pain.
	Diagnosis:
	Diagnosis is done by a specialized Ortho-surgeon after clinical examination together with simple x-rays in standing position and of course the laboratory investigations are supplementary to diagnose any specific cause of the osteoarthritis like rheumatoid, infections, Gout….
	The Operation:
	Under GA, the scar is about 12 cm. long in the anterior aspect of the knee. The patient is mobilized in bed the same day of operation. Next day, the patient starts moving out of his bed under the attending doctor’s supervision. Stitches are removed two weeks after the operation. The patient has to cooperate with the surgeon concerning keeping the scar clean & following up in time when any change takes place.
	What patient age is fit for TKR?
	Usually TKR is done for old aged people. However, in some cases, it might be carried out for younger people due to the advanced degree of degenerative changes & wearing of the joint. These cases are mostly seen after fractures & previous traumatic injuries & sometimes after advanced rheumatoid cases or family inherited cases …etc. the young patient should take into consideration that he might need another T.K.R.(revision) at a later time, because the artificial knee implants have limited age.
	Complications:
	Blood clots & (D.V.T) Deep Vein Thrombosis: have been markedly decreased due to putting the patient on anti-coagulant medications & because of the early mobilization of the patient. Scar complications & infection: this depends on cleanliness & follow-up, besides giving the antibiotics during & post- operatively. This complication rate decreased & almost rare due to the good follow-up between the patient & the surgeon. Even after discharge, the patient has to follow up with the surgeon in case of any infection to be dealt with in the proper way (although the artificial joint is considered as foreign body). Prosthesis fixation complications: Usually the artificial joint implantation is fixed with medical cement, which is considered the best method of fixation at present. Loosening could happen in case of infection or poor bone-quality. Thus it is crucially important to follow up with regular check x-ray especially in the first two years.
	Expected results:
	The pain is relieved almost completely. The patient, depending on the case, could be able to walk the next day of operation & to bend the joint to exceed the right angle before the first week. Usually, the patient could depend on himself /herself in walking & carrying out the usual daily activities by the third to sixth week after operation. Full mobility of the joint depends on the mobility of the joint before the surgery. The better mobility before the operation will help the patient to obtain a better mobility of the joint after the operation. During the last few years, a new prosthesis is developed to enable patients kneeling and squatting to pray after the operation. Some people call it “The Islamic Knee”. Its results are great. It gives similar mobility if not better than other previous implants and can tolerate the charge in full flexion and praying position.