Minimal 11-year follow-up of extensively porous-coated stems in femoral revision total hip arthroplasty☆,☆☆
Section snippets
Defect classification system
The classification system devised by the senior author (W.G.P.) assists the surgeon in planning a femoral revision and predicting the probability of bone ingrowth [2]. The system is divided into 4 categories, based on the extent and location of femoral bone loss, ranging from minimal type I defects to type IV defects, involving extensive femoral metadiaphyseal damage with thin cortices and widened canals (Table 1) [4].
Type of Defect Description of Femur Recommended
Materials and methods
Between 1984 and 1989, 188 consecutive cementless femoral revision surgeries were performed at this institution using extensively porous-coated femoral components (DePuy/Johnson & Johnson, Warsaw, IN). Eighteen patients (18 hips) died or were lost to follow-up. The remaining 170 patients had a mean 14.2-year follow-up (range, 11–16 years). Mean patient age was 61.2 years. The reasons for revision surgery were aseptic loosening (82%), septic loosening (8%), periprosthetic fractures (6%), and
Results
At minimal mean 14.2-year follow-up, 139 hips (82%) had radiographic evidence of bone ingrowth, 24 hips (14%) appeared to have stable fibrous fixation, and 7 hips (4%) were unstable. Six stems had been revised to larger, fully coated cementless implants. Stem subsidence occurred in 27 hips (16%). Unstable stems subsided an average of 7.1 mm (range, 4–10 mm). All radiographically stable stems showed no progression of stem subsidence after 2 years.
Proximal femoral osteolysis was seen in 23% of
Discussion
The current research found that stable biologic fixation of femoral components can be maintained in >95% of cases at 11 to 16 years after revision surgery. Despite observing stress shielding and osteolysis in some patients, we did not observe any cases in which this became a clinical problem or compromised femoral fixation. The femora classified as type IIIB had a lower rate of stable biologic fixation (21% failure rate) with a fully coated cementless stem. Impaction grafting has been found to
Acknowledgements
We thank Peggy Arp for her assistance and support during the preparation of this manuscript.
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Cited by (0)
- ☆
No benefits or funds were received in support of this study.
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Reprint requests: Wayne G. Paprosky, MD, FACS, Central Dupage Hospital, 25 North Winfield Road, Winfield, IL 60190.