Jarcho's 1981 narrative review surveys the preparation, material properties, biologic behavior, and early clinical use of calcium phosphate ceramics — primarily hydroxyapatite (HA) and tricalcium phosphate (TCP) — as candidates for hard tissue prosthetics and bone graft substitutes. It asks: what do we know about biocompatibility, bioresorbability, and mechanical limits, and where can these materials realistically be used?
The inorganic phase of bone is approximately 70% calcium phosphate — the rationale for CaP ceramics was always compositional mimicry of the host tissue. By 1981, early animal and human data had accumulated but no synthesis existed to guide material selection or identify the real constraints on clinical use.
When choosing between CaP materials, composition determines bioresorption rate: TCP resorbs rapidly, HA is effectively permanent, and mixtures allow tuning. Use resorbable TCP-rich formulations where creeping substitution is desired; use HA where long-term scaffold stability is needed.
These materials are best matched to compressive-load environments where conventional bone grafting fails. The atrophic alveolar ridge is the prototype case. Do not use bulk CaP ceramics where torsional, bending, or impact stresses are present.
CaP ceramics cannot replace the osteoinductive capacity of autograft or BMP. When bone induction is the goal, CaP alone will not deliver it. These materials require viable osteogenic cells (autogenous marrow) to produce bone within their structure.
Jarcho closes by predicting that CaP coatings on metallic implants and CaP-containing bone cements would be more impactful than bulk ceramics. A prediction the subsequent decades of cementless HA-coated arthroplasty have borne out.
Jarcho's 1981 narrative review surveys the preparation, material properties, biologic behavior, and early clinical use of calcium phosphate ceramics — primarily hydroxyapatite (HA) and tricalcium phosphate (TCP) — as candidates for hard tissue prosthetics and bone graft substitutes. It asks: what do we know about biocompatibility, bioresorbability, and mechanical limits, and where can these materials realistically be used?
The inorganic phase of bone is approximately 70% calcium phosphate — the rationale for CaP ceramics was always compositional mimicry of the host tissue. By 1981, early animal and human data had accumulated but no synthesis existed to guide material selection or identify the real constraints on clinical use.
When choosing between CaP materials, composition determines bioresorption rate: TCP resorbs rapidly, HA is effectively permanent, and mixtures allow tuning. Use resorbable TCP-rich formulations where creeping substitution is desired; use HA where long-term scaffold stability is needed.
These materials are best matched to compressive-load environments where conventional bone grafting fails. The atrophic alveolar ridge is the prototype case. Do not use bulk CaP ceramics where torsional, bending, or impact stresses are present.
CaP ceramics cannot replace the osteoinductive capacity of autograft or BMP. When bone induction is the goal, CaP alone will not deliver it. These materials require viable osteogenic cells (autogenous marrow) to produce bone within their structure.
Jarcho closes by predicting that CaP coatings on metallic implants and CaP-containing bone cements would be more impactful than bulk ceramics. A prediction the subsequent decades of cementless HA-coated arthroplasty have borne out.