Preparation of hip spacer molds
The hip spacer mold should be filled with 3 to 5 packs (120 gram to 200 gram) of cement depending on the size of the mold used. Use an antibiotic loaded cement.
Mix the cement in a closed mixing system to minimize skin and air exposure.
While the cement is still low in viscosity, fill the stem of the mold first. Insert the syringe into the filling port and fill in a retrograde fashion.
When the stem of the mold is full, direct the nozzle into the head portion of the mold and continue cement injection.
As the mold becomes full, position it so that one of the small vents on the head is facing upward, allowing air to escape as filling is completed. Continue cement delivery while withdrawing the nozzle from the filling port in order to prevent formation of voids.
Place the mold on a flat surface so that it stands on its foot and distal tip. Two to three minutes after filling, observe the level of cement at the filling port. If the level has dropped, inject additional cement to compensate for the pre-cure shrinkage.
As cement cure approaches, ensure that the stem of the mold is straight.
Once cement is cured, press thumbs into the depression on the bottom of the mold foot and peel the mold away from the hip spacer. (If it is difficult to initiate separation, use a scalpel to cut along the joining line of the mold halves near the foot of the mold.)
Trim the hip spacer as necessary.
The function of the temporary joint spacer during the typical 6 to 8 weeks that it will be implanted is local antibiotic therapy, prevention of bone-on-bone contact and contraction of soft tissue about the affected joint, as well as to provide joint stability and non-weight bearing joint articulation.
The temporary joint spacer is not intended for weight-bearing ambulation, and patients are to be warned against such activity