Macroporous calcium phosphate ceramic for long bone surgery in humans and dogs. Clinical and histological study

Abstract

Our previous studies reported the performance of Macroporous Biphasic Calcium Phosphate (MBCP) in spine fusion. In the present study, this material was used in block forms in selected patients with tumoral resection in long bone. Two cases were chosen with large benign bone tumors. Clinical and radiographic assessments, CT scans, and NMR were performed after 16 months, and in one case control biopsies were taken. In order to understand the kinetic process of biodegradation of the MBCP blocks and bone formation at the expense of the ceramics, an experimental study in surgically created bond defects in canine femoral cortices was made. The MBCP blocks recovered after implantation period from 2 to 18 weeks were analyzed using histological, stereological, ultrastructural, electron microprobe, and IR spectroscopy analyses. This study demonstrated the efficiency of MBCP blocks for filling pathological defects in human long bone. The biointegration process of the MBCP blocks was due to a partial dissolution of the ceramics crystals (b-TCP content) by multinucleated cells. Simultaneously, bone ingrowth at the expense of the ceramic is observed. The new bone formation inside the MBCP macropores and in the spaces between the blocks, involved the formation of a new cortical bone on the outer part, and a trabecularlike bone with bone marrow in the inner part of the implant. The biological resorption of the MBCP ceramic decreased after 1 month implantation in dog, due to the protective role of the newly formed lamellar bone on the surface and in the core of the ceramics.

Clinical, radiological and histological study of the failure of cervical interbody fusions with bone substitutes

“…HA is difficult to degrade and the bone/HA bond is ascribed to the biologic apatite microcrystals on the surface [5,10,16]. However, b-TCP is more soluble and bone ingrowth is at the expense of the ceramic [6]. This study documented these different biological processes in human cervical spine.…”

“…The dense ceramic in this study acted only as a spacer. New bone/substitute bond happened both in porous and dense HA [10,25] and new bone formation was at the expense of the b-TCP [6], so the total potential surface for bone ingrowth played a role in the new bone colonization process. High incorporation rate and good clinical results have been reported in anterior cervical interbody fusion with porous coralline HA [22,24], which implied that the porous ceramic could act as a scaffold to support bone ingrowth.…”

Small‐animal models for testing macroporous ceramic bone substitutes

“…The use of a bone substitute with standardized and welldefined physico-chemical and biological properties 26,[35][36][37] led us to predictable results and a direct comparison of bone colonization between animal species and implantation sites. MBCP ceramics have a chemical composition similar to bone mineral and are both biocompatible 38 -40 and bioactive.…”

“…Different animal species have also been used to evaluate bone substitutes. For instance, in vivo studies have been conducted in rats, 10,15,20 rabbits, 8,16,[21][22][23][24][25] dogs, 13,26,27 sheep, 9 and goats. 28 As these animals are different in terms of their metabolisms and bone physiology, direct and strict comparison between all these studies is difficult.…”

Bone substitution in revision hip replacement

“…This property has been named osteoconduction. The use of CPC in clinical studies is more recent [4,22]. Indications include spine arthrodesis [26], filling of cystic cavities, tibial osteotomies and treatment of periodontal osseous defects.…”