The Effect of Risedronate on Posterior Lateral Spinal Fusion in a Rat Model

Abstract

Objective : To evaluate the potential effects of risedronate (RIS) which shows a higher anti-resorptive effect among bisphosphonates, after a posterolateral lumbar intertransverse process spinal fusion using both autograft and allograft in a rat model. Methods : A totoal of 28 Sprague-Dawley rats were randomized into 2 study groups. A posterolateral lumbar intertransverse process spinal fusion was peformed using both autograft and allograft in a rat model. Group I (control) received 0.1 mL of steril saline (placebo) and Group II (treatment) received risedronate, equivalent to human dose (10 µg/kg/week) for 10-weeks period.Results : The fusion rates as determined by manual palpation were 69% in the group I and 46% in the group II (p = 0.251). According to radiographic score, the spinal segment was considered to be fused radiographically in 7 (53%) of the 13 controls and 9 (69%) of the 13 rats treated with RIS (p = 0.851). The mean histological scores were 5.69 ± 0.13 and 3.84 ± 0.43 for the control and treatment groups, respectively. There was a significant difference between the both groups (p = 0.001). The mean bone density of the fusion masses was 86.9 ± 2.34 in the control group and 106.0 ± 3.54 in the RIS treatment group. There was a statistical difference in mean bone densities of the fusion masses comparing the two groups (p = 0.001). Conclusion : In this study, risedronate appears to delay bone fusion in a rat model. This occurs as a result of uncoupling the balanced osteoclastic and osteoblastic activity inherent to bone healing. These findings suggest that a discontinuation of risedronate postoperatively during acute fusion period may be warranted.

Effect of Dietary Calcium on Spinal Bone Fusion in an Ovariectomized Rat Model

“…Recently, a large number of osteoporotic patients with bone fragility have been treated with antiresorptive drugs such as bisphosphonates and selective estrogen receptor modulators after spinal arthrodesis 18 , 23 , 29 , 38) . However, there exists debate about the actual effects of these drugs 24 , 31) , and their use is limited to patients with osteopenia or underestimated osteoporosis due to bony spur or calcified structures around bone.…”

Influence of Alendronate and Endplate Degeneration to Single Level Posterior Lumbar Spinal Interbody Fusion

“…This study demonstrates a solid fusion was achieved in 95% of patients in the alendronate group, and 65% of those in the control group 18) . Most animal studies 1 , 3 , 5 , 13 , 19 , 21 , 26 , 27 , 28 , 29) evaluating the impact of bisphosphonates on fusion rate have not found statistically significant changes with treatment, although this fact may be attributable to low statistical power. The animal literature does suggest that bisphosphonate therapy results in a less histologically mature fusion mass; however, the impact of these changes on fusion mass biomechanics is unclear.…”

Морфологія Формування Поперекового Задньобічного Спондилодезу В Кролів За Умов Використання Кісткових Трансплантатів І Збагаченого Тромбоцитами Фібрину

“…Для гістологічного дослідження виділяли фрагменти поперекового відділу хребта (L IV та L V ). Матеріал фіксували у 10% розчині нейтрального формаліну, декальцинували в 10% розчині мурашиної кислоти, зневоднювали в спиртах висхідної концентрації та заливали в целоїдин [7]…”