Porous Tantalum Tibial Metaphyseal Cones in Revision Total Knee Arthroplasty: Excellent 10-Year Survivorship.

BACKGROUND

Highly porous metal tibial metaphyseal cones (TMCs) are commonly utilized in revision total knee arthroplasty (TKA) to address bone loss and obtain biologic fixation. Mid-term (5 to 10 year) studies have previously demonstrated excellent survivorship and high rates of osseointegration, but longer-term studies are lacking. We aimed to assess long-term (≥ 10 year) implant survivorship, complications, and clinical and radiographic outcomes after revision TKA with TMCs.

METHODS

Between 2004 and 2011, 228 revision TKAs utilizing porous tantalum TMCs with stemmed tibial components were performed at a single institution and were retrospectively reviewed. The mean age at revision was 65 years, the mean body mass index was 33, and 52% were women. Implant survivorship, complications, and clinical and radiographic outcomes were assessed. The mean follow-up was 6.3 years.

RESULTS

The 10-year survivorship free of aseptic loosening leading to TMC removal was 97%, free of any TMC removal was 88%, free of any re-revision was 66%, and free of any reoperation was 58%. The most common indications for re-revision were periprosthetic joint infection, instability, and aseptic femoral component loosening. The 10-year nonoperative complication rate was 24%. The mean Knee Society scores increased from 38 preoperatively to 69 at 10 years. There were 8 knees that had evidence of partial, progressive tibial radiolucencies at 10 years.

CONCLUSIONS

Porous tantalum TMCs demonstrated persistently durable longer-term survivorship with a low rate of implant removal. The rare implant removals for component loosening or instability were offset by those required for periprosthetic joint infection, which accounted for 80% of cone removals. Porous tantalum TMCs provide an extremely reliable tool to address tibial bone loss and achieve durable long-term fixation in revision TKA.

LEVEL OF EVIDENCE

IV.