- Technique Considerations:
- entry into the medullary canal:
- femoral reaming:
- broaching for press fit stems:
- the last broach in inserted carefully and should advance with each blow of the mallet;
- as the broach is inserted be sure that the broach can be backed out without excessive force;
- note that some systems such as biomet has a plasma spray which increases the size of the broach by a fraction of a mm;
- this may impact consideration of the final broach size (and stem size);
- press femoral stem considerations:
- irrigate the canal:
- irrigate the canal inorder to remove fat and marrow elements;
- insertion of femoral stem:
- ensure that the stem advances with each blow of the mallet;
- if there is no advancement, then remove the stem, and rebroach the canal (need to avoid fracture)
- Cautions:
- be sure that the stem advances with each blow of the femur;
- note that an undersized stem may loosen and subside where as an oversized stem may not seat down to the level of the calcar;
- Fracture or Peding Fracture:
- if proximal femoral cortex is thin or if stress risers are present because of previous internal fixation or disease then place a cerclage wire
around femur above the level of lesser troachanter to prevent inadverent fracture;
- if crack does not widen and extends only a short distance, no special treatment is needed, other than careful insertion;
- when crack shows signs of widening or runs more than a short distance, a circumferential wire or cable should be applied;
- during femoral component insertion, if a frx is produced as stem is being seated, then immediately stop and remove stem;
- completely expose frx down to its distal extent;
- if incomplete frx occurs w/ extension only at level of lesser trochanter, then place a cerclage wire around femur above lesser trochanter;
- reinsert the stem, and be certain that wire tightens as stem is seated into position;
- if construct is unstable, then switch to cemented stem
Recognizing anterior metaphyseal femoral bone loss during uncemented total hip arthroplasty: the skylight sign.