TY - JOUR

T1 - Gap healing enhanced by hydroxyapatite coating in dogs

AU - Søballe, K

AU - Hansen, E S

AU - Brockstedt-Rasmussen, H

AU - Hjortdal, V E

AU - Juhl, G I

AU - Pedersen, C M

AU - Hvid, I

AU - Bünger, C

PY - 1991/11

Y1 - 1991/11

N2 - During prosthetic implantation, gaps between the implant surface and the surrounding bone may occur resulting in reduced implant stability. In these instances bone-conductive materials might augment the formation of hosting bone into the pores of the implant and insure earlier implant stabilization and fixation by bony ingrowth. Titanium-alloy cylinders with a porous-titanium-alloy plasma spray coating were implanted into the medial femoral condyles in six mature dogs. In another group of six dogs, matched in age, weight, and gender, hydroxyapatite (HA) coated implants were used. All implants were surrounded by a 1-mm gap. Unilateral osteopenia of the knee, with a 20% reduction of bone density as judged by computed tomography scanning, was induced by 12 weekly intraarticular injections of carrageenin into the right knee before surgery. Four weeks after implantation, the HA-coated implants were compared to the parent porous-titanium implants by mechanical testing and histomorphometry. A marked positive influence of HA coating on bone mineralization and the strength of the interfacial bone between the bone and implant was found. The increment in interface shear strength and shear stiffness was three- to fivefold in osteopenic bone and two-fold in control bone. Coating of an unloaded porous-titanium-coated implant with HA accelerates the rate of bone ingrowth and thereby provides relatively high, early interfacial shear strengths in the presence of an initial gap between bone and implant even in the presence of osteopenic host bone.

AB - During prosthetic implantation, gaps between the implant surface and the surrounding bone may occur resulting in reduced implant stability. In these instances bone-conductive materials might augment the formation of hosting bone into the pores of the implant and insure earlier implant stabilization and fixation by bony ingrowth. Titanium-alloy cylinders with a porous-titanium-alloy plasma spray coating were implanted into the medial femoral condyles in six mature dogs. In another group of six dogs, matched in age, weight, and gender, hydroxyapatite (HA) coated implants were used. All implants were surrounded by a 1-mm gap. Unilateral osteopenia of the knee, with a 20% reduction of bone density as judged by computed tomography scanning, was induced by 12 weekly intraarticular injections of carrageenin into the right knee before surgery. Four weeks after implantation, the HA-coated implants were compared to the parent porous-titanium implants by mechanical testing and histomorphometry. A marked positive influence of HA coating on bone mineralization and the strength of the interfacial bone between the bone and implant was found. The increment in interface shear strength and shear stiffness was three- to fivefold in osteopenic bone and two-fold in control bone. Coating of an unloaded porous-titanium-coated implant with HA accelerates the rate of bone ingrowth and thereby provides relatively high, early interfacial shear strengths in the presence of an initial gap between bone and implant even in the presence of osteopenic host bone.

KW - Animals

KW - Biocompatible Materials

KW - Biomechanical Phenomena

KW - Bone Density

KW - Bone and Bones/surgery

KW - Dogs

KW - Durapatite

KW - Elasticity

KW - Femur/pathology

KW - Hydroxyapatites

KW - In Vitro Techniques

KW - Prostheses and Implants

KW - Tensile Strength

KW - Titanium

KW - Wound Healing/physiology

M3 - Journal article

C2 - 1657476

SP - 300

EP - 307

JO - Clinical Orthopaedics and Related Research

JF - Clinical Orthopaedics and Related Research

SN - 0009-921X

IS - 272

ER -