Survival of Proximal Tibial Endoprostheses Using Compressive Osseointegration: A Multi-Institution Retrospective...

The Compress (CPS) implant is designed to induce osseointegration at the bone-implant interface to reduce rates of aseptic loosening. Previous studies of this implant in the proximal tibia were limited by small, heterogeneous patient cohorts and minimum follow-up.

Our primary outcome is the cumulative incidence of mechanical failure of the CPS implant when used for reconstructions of the proximal tibia for oncologic indications. Secondary aims include types and rates of all CPS failures and risk of any unplanned operation related to the implant.

We conducted a multi-institution retrospective analysis of all patients treated with resection of a primary bone tumor in the proximal tibia, reconstructed with a Compress endoprosthesis, with a minimum 2-year follow-up. Statistical analysis utilized the Kaplan-Meier survival technique and Cox proportional hazard models.

Fifty-three patients met the inclusion criteria. Median follow-up was 7.5 years (range: 1.7-20.1 years). CPS survivorship at 5 and 10 years was 89.8% (95% CI 81.7, 98.7%). There were 21 unplanned reoperations with a 5- and 10-year survival probability of 68.9% (95% CI 56.8%, 83.6%) and 52.5% (95% CI 37.6%, 73.2%).

Compressive osseointegration is a durable technique to anchor large endoprostheses to bone in the proximal tibia.