Analgesic effects and arthritic changes following tramadol administration in a rat hip osteoarthritis model

Abstract

We investigated the analgesic effects of tramadol and the arthritic changes following tramadol administration in the rat hip osteoarthritis (OA) model using mono‐iodoacetate (MIA). The right hip joints of male Sprague–Dawley rats (n = 5 rats/group) in the Sham group were injected with 25 μl of sterile saline and 1% of fluorogold (FG) retrograde neurotracer. In the MIA + Vehicle and MIA + Tramadol groups, FG and 25 μl of sterile saline with 0.5 mg of MIA were injected into the right hip joint. The MIA + Vehicle and MIA + Tramadol groups were administered daily for 4 weeks, either sterile saline (10 mg/kg, intraperitoneal [i.p.]) or tramadol (10 mg/kg, i.p.). We assessed hyperalgesia every week after MIA administration. Histopathological changes and immunoreactive neurons for calcitonin gene‐related peptide (CGRP) in dorsal root ganglia (DRG) were evaluated after 4 weeks of treatment. MIA injection into the hip joint led to mechanical hyperalgesia (p < 0.01), which was significantly reduced by tramadol administration (p < 0.01). Furthermore, daily i.p injection of tramadol significantly suppressed CGRP expression in DRG (p < 0.0001). MIA + Vehicle and MIA + Tramadol groups showed significant cartilage reduction and degeneration compared to the Sham group (p < 0.0001). Interestingly, OA changes significantly progressed in the MIA + Tramadol group compared to the MIA + Vehicle group (p < 0.0001).

Analgesic effects and arthritic changes following intra-articular injection of diclofenac etalhyaluronate in a rat knee osteoarthritis model

“…Pathologically and radiographically, DF-HA was ineffective in improving or inhibiting the progression of joint deformity; in contrast, there was no progression of deformity due to excessive analgesia. As Kanno et al [26] reported, drugs with strong analgesic effects such as tramadol risk worsening arthropathy, but the results of this study showed that DF-HA reduced pain but did not worsen arthropathy. This may be because HA has a protective effect on joints and promotes the synthesis of proteoglycans and glycosaminoglycans [43].…”

“…However, DF-HA may exert better analgesic and jointprotective effects in patients with mild OA. Yoh et al [29] reported that 0.25 mg or 0.5 mg MIA intra-articular injection to hip in rats induced mild OA this year, moreover, Kanno et al [26] also reported arthropathic changes and pain behavior assessment in a rat model of hip osteoarthritis at 0.5 mg MIA. We believe it is necessary to compare the effects of DF-HA with those of low-dose MIA administration models such as 0.25 mg and 0.5 mg in the future.…”

“…As mentioned above, according to a previous study [26], the L3, L4, and L5 level right DRG and lumbar spinal cord of all the rats in both groups were harvested 4 weeks after the administration of DF-HA or vehicle, namely 8 weeks after administration of MIA. The DRG and spinal cord specimens were immersed overnight in phosphate-buffered paraformaldehyde.…”

Is tranexamic acid safe for the hip joint?

“…It is known that the regeneration ability of cartilage tissue is very limited if it is damaged [25]. In the speci c case of femoral head cartilage, studies have shown that the degradation of femoral head cartilage plays an important role in the etiology of osteonecrosis and osteoarthritis of the femoral head [26][27][28]. Osteoarthritis of the hip joint is a health problem that negatively affects the economy due to the loss of work in the working population and high treatment costs [29].…”