Abstract
Sixteen 2- to 3-year-old sheep were submitted to a hemiarthroplasty of the hip joint with a specially designed femoral component. The proximal two thirds of the stem had a circumferential, plasma-sprayed, porous coating with hydroxyapatite. The animals where killed a 15, 30, 60, 90, 120, 180, 200, 270, 360, and 540 days after surgery. Femurs were submitted to plain radiographs, computerised tomography (CT) scan, and dual energy X-ray absorptiometry (DEXA). Cross-sections were obtained at four different levels and studied using scanning electron microscopy. In the coated portion of the stem, apposition of woven immature bone was evident at 15–30 days and mature lamellar bone by 30 days. With time, the gap between the endosteum and the coated surface was filled by bridges of lamellar bone with a marked trabecular orientation. In the distal uncoated portion of the stem, the implant was initially surrounded by fibrous tissue that, with time, transformed into lamellar bone.
Résumé
Seize moutons de 2–3 ans ont subis une hémiarthroplastie de la hanche avec un composant fémoral spécialement conçu. Les 2/3 proximaux de la tige avaient une couche poreuse circonférentielle de plasma vaporisé avec hydroxyapatite. Les animaux ont été sacrifiés aux jours 15, 30, 60, 90, 120, 180, 200, 270, 360 et 540 après chirurgie. Les fémurs ont été soumis à des radiographies ordinaires, une tomodensitométrie, une analyse DEXA. Des sections ont été obtenues à quatre niveaux différents et étudiées en utilisant la microscopie électronique. Dans la portion recouverte de la tige la présence d'os immature était évidente à 15–30 jours et celle d'os lamellaire mature à 30 jours. Avec le temps, l'intervalle entre l'endoste et la surface couverte, a été rempli par des ponts d'os lamellaire d'une orientation trabeculaire marquée. Dans la portion distale, non couverte, de la tige l'implant a été initialement entouré par un tissu fibreux qui avec le temps s'est transformé en os lamellaire.
Full Text
The Full Text of this article is available as a PDF (405.0 KB).
References
- 1.Osborn Biomed Tech. 1987;32:177. doi: 10.1515/bmte.1987.32.7-8.177. [DOI] [PubMed] [Google Scholar]
- 2.Geesink Clin Orthop. 1990;261:39. [PubMed] [Google Scholar]
- 3.CollierJ Arthroplasty 199383898409990 [Google Scholar]
- 4.Soballe K, Hansen ES, Brockstedt-Rasmussen H, Bunger C (1993) Hydroxyapatite coating converts fibrous tissue to bone around loaded implants. J Bone Joint Surg [Br] 75:270–278 [DOI] [PubMed]
- 5.Dalton JE, Cook SD, Thomas KA, Kay JF (1995) The effect of operative fit and hydroxyapatite coating on the mechanical and biological response to porous implants. J Bone Joint Surg [Br] 77:97–110 [DOI] [PubMed]
- 6.Geesink RG, Hoefnagels NHM (1995) Six-year results of hydroxyapatite-coated total hip replacement. J Bone Joint Surg [Br] 77:534–547 [PubMed]
- 7.Engh CA, Hooten JP, Zette-Shaffer K, Ghaffarpour M, McGovern T, Bobyn JD (1995) Evaluation of bone ingrowth in proximally and extensively porous-coated anatomic medullary locking prosthesis retrieved at autopsy. J Bone Joint Surg [Am] 77:903–910 [DOI] [PubMed]
- 8.Soballe K, Overgaard S (1996) The current status of hydroxyapatite coating of prostheses. J Bone Joint Surg [Br] 78:689–691 [PubMed]
- 9.E. Int Orthop. 1996;20:1. doi: 10.1007/pl00006691. [DOI] [PubMed] [Google Scholar]
- 10.Oosterbos Int Orthop. 2001;25:17. doi: 10.1007/s002640000211. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Bucholz Clin Orthop. 2002;395:44. doi: 10.1097/00003086-200202000-00006. [DOI] [PubMed] [Google Scholar]
- 12.GruenClin Orthop 197914117477100 [Google Scholar]
- 13.Johnston RC, Fitzgerald RH Jr, Harris WH, Poss R, Muller ME, Sledge CB (1990) Clinical and radiographic evaluation of total hip replacement. A standard system of terminology for reporting results. J Bone Joint Surg [Am] 72:161–168 [PubMed]
- 14.Karabatsos Clin Orthop. 2001;392:442. doi: 10.1097/00003086-200111000-00058. [DOI] [PubMed] [Google Scholar]
- 15.Lynn Biomaterials. 2002;23:1937. doi: 10.1016/S0142-9612(01)00321-0. [DOI] [PubMed] [Google Scholar]
- 16.Engh J Arthroplasty. 1999;14:637. doi: 10.1016/s0883-5403(99)90091-8. [DOI] [PubMed] [Google Scholar]