The most frequent cause of failure in primary total
hip arthroplastlies is the aseptic loosening of the femoral
component, either in the cemented or uncemented stems,
occurring by different causes. In the cemented stems the first
cause is mechanical due to weakening of the cement mantle
whereas uncemented stems loosen because of fibrous tissue
ingrowth into the pores instead of bone. In cemented femoral
stems, loosening tends to begin lately, but once it occurs the
progression is fast. Uncemented stems may show radiolucent
lines early, but its progression is slower. After a revision
femoral component, the most common complication continues
being aseptic loosening in both types of stems. Several
advantages support the use of cemented femoral stems; the
cement can be associated to antibiotics while obstructing the
migration of polyethylene particles into the femoral metaphysis,
in addition, a good adherence can be achieved with bony
poor quality. The disadvantage is the difficulty of extraction in
the event of failure. The advantages of using uncemented
stems are the possible bone ingrowth on a refreshed bone
bed or bone grafts, and that the extraction of the stem in the
event of failure is less difficult. However, bone ingrowth into
the pores requires such good contact between the implant
and the recipient that is difficult to obtain in revision surgery
with poor bone quality. In the literature, the results in revision
surgery with one or other type of stem are very contradictors,
but a consensus seem to exist in that the election of the type
of femoral component depends on several factors like life
expectancy, activity requirement, obesity, bone quality, quantity
of remnant bone stock and geometry of the proximal
femur. The most important factor in the durability of revision
hip arthroplasty is the bone quality: with good bone quality the
results tend be favorable, regardless of the type of used stem;
but with poor bone quality the results tend be worse with no
cemented femoral components.

The most frequent cause of failure in primary total
hip arthroplastlies is the aseptic loosening of the femoral
component, either in the cemented or uncemented stems,
occurring by different causes. In the cemented stems the first
cause is mechanical due to weakening of the cement mantle
whereas uncemented stems loosen because of fibrous tissue
ingrowth into the pores instead of bone. In cemented femoral
stems, loosening tends to begin lately, but once it occurs the
progression is fast. Uncemented stems may show radiolucent
lines early, but its progression is slower. After a revision
femoral component, the most common complication continues
being aseptic loosening in both types of stems. Several
advantages support the use of cemented femoral stems; the
cement can be associated to antibiotics while obstructing the
migration of polyethylene particles into the femoral metaphysis,
in addition, a good adherence can be achieved with bony
poor quality. The disadvantage is the difficulty of extraction in
the event of failure. The advantages of using uncemented
stems are the possible bone ingrowth on a refreshed bone
bed or bone grafts, and that the extraction of the stem in the
event of failure is less difficult. However, bone ingrowth into
the pores requires such good contact between the implant
and the recipient that is difficult to obtain in revision surgery
with poor bone quality. In the literature, the results in revision
surgery with one or other type of stem are very contradictors,
but a consensus seem to exist in that the election of the type
of femoral component depends on several factors like life
expectancy, activity requirement, obesity, bone quality, quantity
of remnant bone stock and geometry of the proximal
femur. The most important factor in the durability of revision
hip arthroplasty is the bone quality: with good bone quality the
results tend be favorable, regardless of the type of used stem;
but with poor bone quality the results tend be worse with no
cemented femoral components.