ABSTRACT
ABSTRACT: Bone trauma triggers an acute inflammatory response, which can alter the serum concentration of acute-phase proteins (PFA). We aimed to evaluate the effectiveness of PFA measurement as a laboratory biomarker for inflammation related to bone regeneration. A partial ostectomy of the right radius was performed on 22 young male rabbits. The complete blood count, albumin, ceruloplasmin, haptoglobin, C-reactive protein, and transferrin levels were recorded and correlated with the radiographic evolution of bone healing. Statistically the best correlations with the inflammatory process and radiological findings were reported with haptoglobin and transferrin compared to the other measured PFAs. Haptoglobin and transferrin showed a maximum peak 24 and 36 hours after surgery, respectively. Transferrin displayed signs of decrease in the first 6 hours after surgery, in advance of the leukocyte response. The measurement of acute-phase proteins proved to be viable, considering the conditions in which the present study was carried out. Among all variables studied, haptoglobin and transferrin showed best correlation with the inflammatory process of bone healing. Additional studies are needed to determine the sensitivity of acute-phase proteins as predictors of complications in the treatment of fractures.
RESUMO: Os traumas ósseos desencadeiam resposta inflamatória aguda e consequentemente alteram a concentração sérica das proteínas de fase aguda (PFA), podendo essas representarem um parâmetro para avaliação da evolução do processo inflamatório relacionado à cicatrização óssea, assim como complicações. Objetivou-se avaliar a inter-relação da mensuração de PFAs com a repação óssea em coelhos submetidos à ostectomia parcial do rádio. Foram utilizados 22 coelhos, machos, jovens (160 a 180 dias) e peso médio (3,8 ± 0,3). Para acompanhamento da evolução do processo inflamatório foram realizados hemograma completo e mensuração de albumina, ceruloplasmina, haptoglobina, proteína C reativa e transferrina, além do acompanhamento radiológico. Foi observado a melhor correlação da haptoglobina e da transferrina junto ao processo inflamatório e achados radiológicos frente às demais PFAs mensuradas. A haptoglobina apresentou pico máximo 24 horas do pós-operatório e a transferrina após 36 horas, entretanto, essa última já mostrou indícios de diminuição nas primeiras 6 horas do pós-cirúrgico, antecipadamente à resposta leucocitária. Nas condições em que o presente estudo foi realizado, a mensuração das proteínas de fase aguda mostrou-se factível. Das proteínas estudadas, a haptoglobina e transferrina foram as que mostraram maior correlação com o processo inflamatório da cicatrização óssea. Estudos adicionais são necessários para determinar a sensibilidade das proteínas de fase aguda como previsores de complicações do tratamento das fraturas.
ABSTRACT
Abstract Purpose To evaluate the use of demineralized bone matrix of caprine origin in experimental bone defects of the tibia in New Zealand rabbits. Methods Fragments of the tibia diaphysis were collected aseptically from clinically healthy goats. The bones were sectioned into 1 cm fragments and stored at -20°C for subsequent hydrochloric acid (HCL) demineralization. A 70 mg portion of DBMc was used to fill the experimental bone defects. Twenty-four female adult New Zealand rabbits were divided into 2 groups: the MG (matrix group, left tibia) and CG (control group, right tibia). Additionally, they were separated into 4 groups with 6 animals, according to the period of analysis (15, 30, 60 and 90 days postoperatively). Using microCT, volumetric parameters were evaluated: bone volume, relationship between bone volume and total volume, bone surface area, relationship between bone surface area and total volume, number of trabeculae, trabecular thickness and trabecular separation. Results There was a statistically significant difference (P<0.05) between groups considering bone volume (BV) and bone:total volume (BV/TV), on 15, 30 and 90 days postoperatively. Control group showed a statistically significant superiority (P < 0.05) considering the mean of the variables bone surface (BS), number of trabeculae (Tb.N) and between bone surface and total volume (BS/TV) at 15 and 90 days. Conclusions Caprine demineralized bone matrix was safe and tolerable. No signs of material rejection were seen macroscopically. It is an alternative for the treatment of bone defects when autologous graft is not available or in insufficient quantities.