A computer-assisted microscopic analysis of bone tissue developed inside a polyactive polymer implanted into an equine articular surface
Réka Albert1*, Gábor Vásárhelyi2, Gábor Bodó3, Annamária Kenyeres1, Ervin Wolf1, Tamás Papp1, Tünde Terdik1, László Módis1 and Szabolcs Felszeghy1
1Department of Anatomy, Histology and Embryology, Medical and Health Science Centre, University of Debrecen, Debrecen, Hungary, 2Orthopaedic and Trauma Department, Uzsoki Hospital, Budapest, Hungary and 3Department of Surgery, Faculty of Veterinary Medicine, Szent István University, Budapest, Hungary
*Present address: Department of Biochemistry and Molecular Biology, Medical and Health Science Center, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Offprint requests to: Szabolcs Felszeghy, Department of Anatomy, Histology and Embryology, Medical and Health Science Centre, University of Debrecen, Nagyerdei krt. 98., 4032, Debrecen, Hungary. e-mail: szabi@chondron.anat.dote.hu
Summary. One of the most promising applications for the restoration of small or moderately sized focal articular lesions is mosaicplasty (MP). Although recurrent hemarthrosis is a rare complication after MP, recently, various strategies have been designed to find an effective filling material to prevent postoperative bleeding from the donor site. The porous biodegradable polymer Polyactive (PA; a polyethylene glycol terephthalate - polybutylene terephthalate copolymer) represents a promising solution in this respect. A histological evaluation of the longterm PA-filled donor sites obtained from 10 experimental horses was performed. In this study, attention was primarily focused on the bone tissue developed in the plug. A computer-assisted image analysis and quantitative polarized light microscopic measurements of decalcified, longitudinally sectioned, dimethylmethylene blue (DMMB)- and picrosirius red (PS) stained sections revealed that the coverage area of the bone trabecules in the PA-filled donor tunnels was substantially (25%) enlarged compared to the neighboring cancellous bone. For this quantification, identical ROIs (regions of interest) were used and compared. The birefringence retardation values were also measured with a polarized light microscope using monochromatic light. Identical retardation values could be recorded from the bone trabeculae developed in the PA and in the neighboring bone, which indicates that the collagen orientation pattern does not differ significantly among these bone trabecules. Based on our new data, we speculate that PA promotes bone formation, and some of the currently identified degradation products of PA may enhance osteo-conduction and osteoinduction inside the donor canal. Histol Histopathol 27, 1203-1209 (2012)
Key words: Mosaicplasty, Donor tunnels, Bone, Polarized light microscopy, Computer-assisted image analysis, Horse
DOI: 10.14670/HH-27.1203