Authors reviewed 60 cases of bipolar hip arthroplasty which had used uncemented femoral components and followed more than 1 year(ranged from 1 year to 7 years 3 months. months. mean, 37.1 months) to identify overall incidence of osteolysis
compare
to
that in THA, incidece of osteolysis according to type of implant, time noted first, radiographic distribution of osteolysis and suggestive sources of debris from revised hips.
@ES The results were followings:
1) Overall incidence of femoral endosteal osteolysis in bipolar hip arthroplasty, 18.3%, was significantly higher that in THA, 6.3%, with the use of similar kind of uncemented femoral components and similar period of follow up.
2) Uncemented femoral components with circumferential pad had significantly lower incidence
of osteolysis compared to those with non-circumferential pad.
3) Osteolysis was first noted radiographically at 12 to 56 months(Mean, 33.8 months).
4) Osteolysis occured most frequently at Zone 3 on A-P and lateral radiographs.
5) Suggestive sources of osteolysis in BHA derived from revisions were impingement of polyethylene cup rim on the femoral neck, wear at inner articulation(polyethylene/metal head), and wear at outer surface of polyethylene liner(polyethlene/metal
cup)
Conclusively, be cautious to choose BHA even if acetabular condition is sound because of significantly higher incidence of femoral endosteal osteolysis in BHA compare to that in THA. Hopefully, it may by careful to improve or revise design BHA
for
reducing wear.
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