The RIPO register collects data of all primary and revision hip replacement surgeries performed in Region Emilia-Romagna, Italy since 1stJanuary 2000.

The present study is aimed to analyze the survival rate of patients with Biolox®delta and Biolox®forte components, (CeramTec, Plochingen Germany) considering possible confounding factors. Only patients living in the region are considered in analysis, to avoid the bias resulting from the ‘loss’ of non-resident patients. The analysis has been conducted only on uncemented THA and monoblock, double mobility cups as well as such with pre-assembled inserts were excluded. Therefore, the finally analyzed database consists of 30’617 cases; 13’323 Biolox®forte and 17’294 Biolox®delta heads, articulating against ceramic or PE.

Unadjusted survival analysis was calculated according to Kaplan Meier method; with prosthesis failure as end point, defined as the revision of any prosthetic component for any cause.

To avoid a possible bias, revision of the prosthesis due to breakage of modular necks of the stem have not been considered. The results are summarized in Table 1.

*survival at 6 yrs follow-up

After adjusting for age and gender it resulted that Biolox®delta - XLpoly and Biolox®forte – poly increase the risk of revision (HR 1.4 and 1.2) compared to Biolox®delta - Biolox®delta;

When only ceramic fractures are considered, we observed 1 fracture of a 36 mm Delta head (1/8’917 = 0.01%) and 38 fractures of 28 mm Forte heads. The 38 fractures occurred mainly in cer-cer coupling (35/3’537 implants= 1%) and occasionally in cer-poly couplings (3/4’246 implants = 0.07%).

Fracture or damage of the Biolox®delta insert occurred in 10 implants out of 14’260(0.07%), while it had a higher incidence in Forte inserts (36 casesout of 6’932 implants = 0.52%).

It can be concluded that the presence of a poly liner decrease the survival of the implant. Beside this Biolox®delta significantly improved the resistance to fracture of both head and insert.