Insertion of Cementless Femoral Stem



- 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



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Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, May 17, 2012 9:49 am