Bone growth into porous high‐density polyethylene

Abstract

The purpose of this study was to delineate the process by which bone comes to fill the pores of porous high-density polyethylene (PHDPE) implants. PHDPE (450 mu pore size) pellets 4 mm in diameter and 1 cm long were implanted into the femurs of dogs. A bone biopsy procedure was utilized to obtain PHDPE pellets implanted for periods of 3 days through 8 weeks. A one-year biopsy specimen taken from the PHDPE coating on the stem of a canine total-hip prosthesis was also studied. The results demonstrated that significant amounts of bone formed within the PHDPE pellets as early as 14 days after implantation. Bone was identified throughout the specimens after 4 weeks. After 6 weeks, the tissue in hematopoietic marrow. Scanning electron microscopy was utilized in conjunction with light microscopy and microradiography to study the ultrastructural features of the bone ingrowth process.

Osteogenic Phenomena Across Endosteal Bone-Implant Spaces with Porous Surfaced Intramedullary Implants

“…Experimental studies on the concept of biological fixation of implants have clearly demonstrated bone growth into porous ceramics (Hulbert et al 1970, Cameron et al 1977, polymers (Howe et al 1974, Spector et al 1976), 000 1 -6470/81/020145-09 $02..50/0 1 0 and metals (Galante et al 1971, Hirschhorn et al 1971, Bobyn 1977. Several investigators have established firm fixation of porous intramedullary rods or nails by osseous tissue ingrowth.…”

Bone growth into glassy carbon implants: A rabbit experiment

“…Bone grows into porous ceramic, metallic or polymeric biocompatible materials which have sufficient interconnecting pore size (Hulbert et al 1970, Cameron et al 1976, Spector et al 1976). Hulbert and his associates showed that a pore size of 100 pm will allow bone ingrowth while a pore size of 150 Krn will permit osteon formation.…”

Modern Porous Coatings in Orthopaedic Applications

“…While stainless steel porous coatings provided rigid fixation and pore sizes adequate for osseous integration, the material was found to undergo excessive in vivo corrosion. Similarly, several porous polymers, including porous polysulfone, porous polyethylene and Proplast (a Teflon/graphite fiber material composite) were found to have inadequate strength, unacceptable wear, and high failure rates [87][88][89].…”

“…Other materials, including porous stainless steel as an implant in bone [18] as well as porous polymers as prosthetic coatings [87][88][89] were investigated as potential materials for improved bone ingrowth, however certain shortcomings prohibited their widespread clinical applications. While stainless steel porous coatings provided rigid fixation and pore sizes adequate for osseous integration, the material was found to undergo excessive in vivo corrosion.…”