The Biocompatibility of Degradable Magnesium Interference Screws: An Experimental Study with Sheep

Table 1

Allocation of the materials representing the different interference screws in relation to the different examination times. A total of 30 screws (two per animal) were used.

Interference screw	Fabrication procedure	6 weeks	3 months	12 months
PLLA		2	2	2
Titanium		2	2	—
W4, diecasted	> 100 bar, > 700°C;	2	—	—
W4, diecasted	> 100 bar, > 600°C; coating: CaO, CaHPO4, Mg(OH)2, nanohydroxyapatite (suspension), Ca(H2PO4), Na-silicate (Na2O·3SiO2)	—	2	—
W4, diecasted,; coating no. 9	> 100 bar, > 600°C; coating: CaO, CaHPO4, Mg(OH)2, nanohydroxyapatite (suspension), Ca(H2PO4), Na-silicate (Na2O·3SiO2) zinkoxide	2	—	—
W4, diecasted,; coating no. 8	> 100 bar, > 700°C; coating: CaO, CaHPO4, Mg(OH)2, nanohydroxyapatite (suspension), Ca(H2PO4), Na-silicate (Na2O·3SiO2)	2	—	—
W4, diecasted,; coated 150 s	> 100 bar, > 600°C; coating: CaO, CaHPO4, Mg(OH)2, nanohydroxyapatite (suspension), Ca(H2PO4), Na-silicate (Na2O·3SiO2)	—	2	—
W4, diecasted,; coated 300 s	> 100 bar, > 600°C; coating: CaO, CaHPO4, Mg(OH)2, nanohydroxyapatite (suspension), Ca(H2PO4), Na-silicate (Na2O·3SiO2)	—	2	2
W4, milled	Milled out of a two-step extruded cast	2	2	2