The effect of Theranekron on femur fracture healing in an experimental rat model

The effects of hydroxychloroquine-induced oxidative stress on fracture healing in an experimental rat model

OBJECTIVES

The purpose of this study was to investigate whether hydroxychloroquine (HCQ) sulfate causes oxidative stress (OS) and its effect on fracture healing in an experimental rat model.

MATERIALS AND METHODS

In this experimental study, open diaphyseal femur fractures were induced in 24 eight-week-old male rats (mean weight: 225±25 g; range, 200 to 250 g) and then fixed with K-wire. The rats were divided into four groups: HCQ-2, control-2 (C-2), HCQ-4, and control-4 (C-4). During the study period, rats in the HCQ groups received an HCQ solution (160 mg/kg/day), whereas rats in the control groups received saline. The HCQ-2 and C-2 groups were sacrificed on the 14th day, and the HCQ-4 and C-4 groups were sacrificed on the 28th day. After sacrifice, malondialdehyde levels induced by OS were calculated for each rat, and fracture healing was evaluated radiographically, histomorphometrically, histopathologically, and immunohistochemically.

RESULTS

Malondialdehyde levels were higher in the HCQ groups than in the control groups (p<0.05). Hydroxychloroquine caused OS in rats. The ratio of total callus diameter to femur bone diameter was lower in HCQ groups compared to control groups (p<0.05). No differences were observed when comparing radiological and histological healing results between the control and HCQ groups. Alkaline phosphatase levels were lower in the HCQ-4 group than the C-4 group at week four (p<0.05), although osteocalcin and osteopontin levels did not differ between groups (p>0.05). Oxidative stress had no adverse effects on histologic healing outcomes and osteoblast functions. Cathepsin K and tartrate-resistant acid phosphatase-5b levels were higher in the HCQ-4 group than in the C-4 group (p<0.05). While the number and function of osteoclasts increased due to OS in callus tissue, a decrease in the number of chondrocytes was observed.

CONCLUSION

Hydroxychloroquine-induced OS increases the number and function of osteoclasts and decreases the number of hypertrophic chondrocytes and endochondral ossification but has no significant effect on mid-late osteoblast products and histological fracture healing scores.

Vitamin D3 and omega-3 polyunsaturated fatty acids have beneficial effects on fracture union in an experimental rat model

OBJECTIVES

This study aimed to determine the influences of vitamin D3 and omega-3 polyunsaturated fatty acids (PUFAs) on fracture union in rats radiologically, histologically, and biomechanically.

MATERIALS AND METHODS

Forty-eight male Sprague-Dawley rats (mean weight: 435±31.15 g; range, 398 to 510 g) were indiscriminately separated into four groups, with 12 rats in each: Group 1 was the control group, Group 2 received vitamin D3, Group 3 received omega-3 PUFA, and Group 4 received both vitamin D3 and omega-3 PUFA. One day after surgery, only one intramuscular dose of 50,000 IU/kg vitamin D3 was administered to Group 2. From the first postoperative day until sacrification, 300 mg/kg omega-3 PUFA by oral feeding was administered to Group 3. In Group 4, both an intramuscular dose of 50,000 IU/kg vitamin D3 on the initial postoperative day and 300 mg/kg omega-3 PUFA were administered by oral feeding until sacrification. All rats were sacrificed by intracardiac potassium injection at the sixth postoperative week, and radiological, biomechanical, and histological studies were conducted.

RESULTS

According to the radiological scores, the best scores were obtained in Group 4, and callus density and ossification were advanced in Groups 2 and 3 compared to Group 1. There was no statistically significant distinction between Groups 3 and 4, while a significant distinction was found between Group 4 and Groups 1 and 2. Biomechanically, the advanced values were attained in Groups 1 and 3. However, there was no statistically significant distinction among the groups. Histologically, although the advanced scores were attained in Groups 3 and 4, there was no statistically significant distinction among the groups.

CONCLUSION

The use of omega-3 PUFA together with vitamin D3 might have beneficial influences on fracture union. In the future, the combination of omega-3 PUFA and vitamin D3 might be used as an encouraging treatment choice that contributes to fracture healing.