This study was conducted to reveal whether the intraoperative intravenous and periarticular injection of glucocorticoids have different clinical outcomes following primary TKA and which administration route may be more recommended. In the present study, we found that the ROM of knee in the affected leg at post-operative 3 months was less in the IV group than in the PI group (P < 0.05), but without a statistically significant difference at 3rd days and 2 weeks postoperatively between the groups (P > 0.05). Additionally, there was no significant difference in postoperative VAS score, knee swelling, KSS function score, inflammation markers and complications occurrence between the two groups after TKA.
Intravenous and periarticular injection of glucocorticoids have been proven to be effective way to relieve pain after artificial joint replacement, but the best way to use glucocorticoids to relieve pain in TKA has not been determined. According to our outcomes, the intravenous (IV) dexamethasone made similar performance on pain scores at rest and during walking at 6 hours, 1st, 2nd, 3rd, 4th days, 2 weeks and 3 months postoperatively compared with the periarticular injection (PI) of dexamethasone after TKA, which suggested that the intravenous and periarticular injection of 10 mg dexamethasone have similar effect to relieve the early postoperative pain of TKA. However, Hatayama[21] and Li[22] argued that the pain scores at rest and during walking were significantly lower in patients who received periarticular injection of glucocorticoids than those who received intravenous administration of glucocorticoids in the early post-TKA period, which is not consistent with our results. In the Hatayama’s study, the intravenous administration group received 10 mg dexamethasone but the periarticular injection group received a 40-mg triamcinolone acetonide, which might have contributed to the difference in results[21].
Pain scores is greatly affected by subjective factors, but the inflammation marker is an objective indicator which could provide more reliable clinical outcomes. IL-6 is widely associated with inflammation, which has a vital role in the process of neutrophils and macrophage activation during surgery and trauma, and IL-6 can induce the production of CRP in hepatocytes[23, 24]. Previous studies revealed that the serum inflammatory cytokines including interleukins (ILs), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) might be related to postoperative pain[25–29]. Si[29] suggested that serum inflammatory cytokines are positively correlated with acute postoperative pain following primary TKA. In the present study, there were no significant differences in the mean IL-6, CRP and ESR at 1st days and 3rd days postoperatively between the two groups, showing the similar anti-inflammatory effect of dexamethasone in IV group and PI group in the early postoperative period. This result could explain similar postoperative pain-alleviating effects between groups, and it further confirmed the reliability of the pain scores results. Li[22] showed that IL-6 and CRP in the early postoperative period after TKA were significantly higher in topical dexamethasone group, but the postoperative pain scores were significantly lower in topical group comparing with intravenous group, which was not consistent with our results.
In addition, the inflammatory responses after surgical injury contribute to the knee swelling and impaired function of knee[30, 31]. Anti-inflammatory treatment can reduce knee swelling effectively, especially at the early postoperative stage. Rytter[31] reported that preoperative intravenous methylprednisolone was able to effectively reduce knee swelling within 24 hours after TKA. However, Klement[32] showed that a reduction in knee swelling after TKA was reported in 65.4% of patients who received periarticular injection of glucocorticoids. In this study, we found the similar outcomes between the two groups on reducing the knee swelling, the ROM of knee and the KSS score evaluated at 3rd days postoperatively. These results illustrate that the intravenous and periarticular injection of dexamethasone play the same role in improving knee swelling and knee function recovery after TKA. It is worth mentioning that the ROM of knee was larger in PI group at post-operative 3 months.
Although glucocorticoids have obvious benefits in the perioperative period of artificial joint replacement, its application in the perioperative period of total joint replacement has not become a routine due to the concern of related side effects. However, these side effects are only related to the long-term use of glucocorticoids. Numerous studies have revealed that there was no significant increase of adverse reactions for patients who used glucocorticoids in perioperative period[33–35]. The complications including vomiting, wound drainage, delayed wound healing, blood transfusion, deep vein thrombosis, pulmonary embolism, periprosthetic infection, avascular necrosis and the consumption of ondansetron and opioids were similar between IV group and PI group.
This study had several limitations. First, patients in this study were from a single center with a short period. Second, the numbers of patients included in this study were limited. Third, all patients underwent adductor block, and the pain scale may be masked in the early postoperative period. However, we had to implement adductor nerve block to minimize pain and nausea after TKA due to ethical considerations.
In conclusion, this study supported that the intraoperative intravenous and periarticular injection of glucocorticoids have similar clinical outcomes, including postoperative pain management, prevention of PONV, inflammation, knee swelling, knee function recovery and the incidence of complications following primary TKA.