Collarless polished tapered impaction grafting of the femur during revision total hip arthroplasty - Pitfalls of the surgical technique and follow-upin 31 cases

Impacting morcellized allograft bone into the femur during revision total h ip arthroplasty is a simple concept with the goal of rebuilding femoral bon e stock and providing secure fixation to the femoral stem. Using the collar less polished tapered (CPT, Zimmer, Warsaw, IN) stem impaction grafting sys tem, we became concerned about the discrepancy between the straightforward concept and precise execution of the technique. In this study, we examined 31 consecutive procedures to determine intraoperative difficulties and repo rt on the clinical outcome of 30 cases at an average follow-up of 31 months . Modified Harris Hip Scores averaged 41 points preoperatively and improved to 86 points at follow-up. Nineteen cases were performed on intact femora, whereas 12 cases had disrupted femoral integrity, either extended trochant eric osteotomy or periprosthetic fracture. Successful outcome was seen in a ll cases with an intact femur, and restoration of femoral integrity was key to successful outcome in cases with compromised femoral integrity. Among c ases with disrupted femoral integrity, 3 distal Fractures occurred as a res ult of the rigid CPT cement plug, and 2 complete femoral fractures occurred as a result of bone impaction, for a technique-related fracture rate of 16 %. Difficulty packing bone distally occurred in 94% of cases and was associ ated with varus and valgus stem alignment and medial and lateral stem displ acement. Complete cement mantles were seen in 77% of cases. No stem subside nce was seen in 15 of 30 cases (50%). Stent subsidence of <5 mm was seen in 10 of 30, stem subsidence of 6 to 8 mm was seen in 4 of 30, and stem subsi dence of >10 mm was seen in 1 patient (4%). of the patients, 87% thought th e procedure improved their function, and 97% would recommend it to a friend with a failed femoral component. Although we hope that the instruments for this procedure can improve, we endorse the concept of impaction grafting w ith the CPT stem as a successful way of dealing with revision femoral surge ry.