| 摘要 |
FIELD: medicine. ^ SUBSTANCE: invention concerns medicine and can be used in traumatology and orthopaedics. A stem of titanium alloy contains an intramedullar part and a collar. The intramedullar part implanted in intramedullary cavity of femur is convergent towards a distal end, and has proximal, subproximal and distal portions. The cross section has two parallel sides related to front forward and back surfaces of the stem. The sides related to medial and lateral surfaces of the subproximal and distal portions of the stem, and to the medial surface of the proximal portion of the stem have convex curves. The medial surface of the proximal portion is smoothly radially conjugated with the medial surface of the subproximal portion and the collar of the stem. The surface roughness values Rz of the subproximal portion of the intramedullar part are not less than 20 mcm. The proximal portion has a two-layer macrostructure an inside layer of which represents a high-strength substrate, and a surface layer is a porous coating with an average pore size 50-500 mcm. The distal portion has a modified surface with roughness Ra no more than 0.1 mcm and microhardness H not less than 4000 MPa. ^ EFFECT: ensured prolonged stability of the stem with reduced time of postoperative rehabilitation. ^ 4 cl, 3 dwg, 3 ex |
