Effect of nandrolone decanoate on healing of experimentally induced radial nonunion in rabbits (Oryctolagus cuniculus)

The aim of this study was to evaluate the effect of nandrolone decanoate (ND) on treatment of bone nonunion in the radius of rabbits. Thirty-one, young adult, New Zealand White rabbits (Oryctolagus cuniculus) were allocated to one of four groups: nandrolone males (NMG), nandrolone females (NFG), placebo males (NPM), and placebo females (NPF). After bone nonunion of a 10 mm ostectomy of the radius was confirmed (45 days after surgery), the animals in the NMG and NFG groups received 10 mg/kg ND intramuscular once a week for four weeks, while placebo groups received intramuscular 0.9% NaCl solution. Radiographic, histopathologic, and densitometric parameters (DXA) were used to compared groups. Results No significant differences were observed radiographically. However, ND groups showed greater area (P=0.0258) and BMC (P=0.0140) in the densitometric evaluation. Histologically, the placebo group showed a predominance of primary bone tissue. Whereas, lamellary organizations of secondary bone and the presence of fibrocartilage were found in the ND group (P =0.006). In conclusion, ND promoted bone regeneration after the creation of a large defect in the radius of rabbits.


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Delayed union and nonunion are common complications of osteosynthesis of long 23 bones in small animal practice. There are many factors resulting in nonunion, including 24 mechanical failures (excessive movement and/or the presence of large bone defects), and 26 of nonunion is the bioactivation of the fracture environment and the filling of critical defects.
27 Classically, the use of bone grafts, bone marrow, and other activation factors has been used; 28 despite treatment a significant proportion of nonunions fail to heal, especially in small dogs 29 (3,4).
30 Steroids are known to affect bone health and there has been increasing interest in the effect of 31 hormones on bone regeneration. In vitro, osteoblastic cells may be stimulated by androgens.
32 Several studies have looked at the use of anabolic steroids as adjuncts to bone repair. Although    The animals received enrofloxacin (10 mg/kg every 24 hours for 7 days 76 subcutaneously), tramadol hydrochloride (5 mg/kg every 12 hours for 3 days subcutaneously) 77 and meloxicam (1 mg/kg single dose subcutaneously) postoperatively.

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All rabbits underwent radiographic examination immediately after surgery and on 15,    The area (cm²) and BMC were similar between females and males (P> 0.05; Table 2).
156 BMC (P = 0.0140; Fig. 3) than the Placebo groups. There was an effect of the interaction 157 between sex and treatment in the BMD (g / cm2) (

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In previous studies on ND in guinea pigs, its effectiveness in bone activity was observed; 229 however, these studies are limited because they were evaluated qualitatively. In this study, the 230 evaluations were scored to achieve greater accuracy and reliability of the results (5, 7).

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In addition to evaluating the effect of ND on atrophic nonunion, we hypothesised that 232 androgenic therapies might be affected by the physiological and hormonal differences between 242 suggests that androgens are essential for optimal bone healing.

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The same finding was observed in studies that involved osteoporotic women treated 244 with ND. In another study, men showed a 50% increase in the risk of pathological fractures 245 resulting from osteopenia following orchiectomy for gonadal tumours when compared to those 246 who had not undergone the procedure. No decrease in BMD on bone densitometry was seen 247 in men who received androgen therapy in contrast to untreated men (13, 14).

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The animals in the nandrolone group showed a greater BMC then the placebo group. 253 BMD in male rats after 28 days of treatment and found no significant differences between the 254 treated and control groups. From this, we derive another hypothesis that the beneficial effects 255 of ND may occur later than expected. In our study, we observed any improvement in bone 256 quality from the thirtieth day of treatment.

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The microscopic findings showed that the animals in placebo groups had a

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The degree of fibrocartilaginous tissue formation was different for males and females.
265 This effect of androgens may be important in males, since they are present in higher 266 concentrations and contribute to greater periosteal bone formation and, therefore, greater bone 268 fibrocartilaginous tissue in the NMG. The extent of direct interaction between androgens and 269 osteoblasts or their precursors is still unclear. Androgens affect skeletal growth, including the 270 increase in vascular and muscle cell activity (13).

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In this study, treatment with ND resulted in improvement in bone healing in nonunion 272 fractures. However, complete healing did not occur in the NG or PG, as expected, due to the 273 restricted duration of the study. The most important limitation in this study was the inability to