A prosthesis comprising: an inner layer (4) formed from a polyaryletherketone； a first outer layer (2a) adjacent to said inner layer formed from a porous polyaryletherketone, at least some of said pores having located therein material to promote osteointegration； and a second outer layer (2b) adjacent to said first outer layer formed from a porous polyaryletherketone, a portion of said pores being free of material to promote osteointegration. The invention also relates to a method of manufacture of the prosthesis. In an alternative arrangement, the prosthesis comprises: an inner layer formed from a polyaryletherketone； a first outer layer adjacent to said inner layer formed from a porous polyaryletherketone, at least some of said pores having located therein material to promote osteointegration having a crystallinity of from about 60 % to about 9 0 %； and a second outer layer adjacent to said first outer layer formed from a porous polyaryletherketone, at least a portion of said pores having located therein material to promote osteointegration having a crystallinity of less than about 50 %.
