Does Limb Preconditioning Reduce Pain After Total Knee Arthroplasty? A Randomized, Double-blind Study

Abstract

Background Total knee arthroplasty (TKA) can be associated with considerable postoperative pain. Ischemic preconditioning of tissue before inducing procedure-related underperfusion may reduce the postoperative inflammatory response, which further may reduce associated pain. Questions/purposes In this prospective, randomized study, we aimed at evaluating the impact of ischemic preconditioning on postoperative pain at rest and during exercise; use of pain medication; levels of systemic prothrombotic and local inflammatory markers; and length of stay and achievement of physical therapy milestones. Methods Sixty patients undergoing unilateral TKA under tourniquet were enrolled with half (N = 30) being randomized to an episode of limb preconditioning before induction of ischemia for surgery (tourniquet inflation). Pain scores, analgesic consumption, markers of inflammation (interleukin-6 [IL-6], tumor necrosis factor [TNF]-a in periarticular drainage), and periarticular circumference were measured at baseline and during 2 days postoperatively. Changes in prothrombotic markers were evaluated. Results Patients in the preconditioning group had significantly less pain postoperatively at rest (mean difference = À0.71, 95% confidence interval [CI] = À1.40 to À0.02, p = 0.043) and with exercise (mean difference = À1.38, 95% CI = À2.32 to À0.44, p = 0.004), but showed no differences in analgesic consumption. No differences were seen between the study and the control group in terms of muscle oxygenation and intraarticular levels of IL-6 and TNF-a as well as levels of prothrombotic markers. No differences were found between groups in regard to hospitalization length and time to various physical therapy milestones. Conclusions Ischemic preconditioning reduces postoperative pain after TKA, but the treatment effect size we observed with the preconditioning routine used was modest.

Does ischemic preconditioning preoperatively reduce postoperative pain and analgesic requirement in total knee arthroplasty?

“…Memtsoudis et al, in a similar study had chosen a 5 minutes period of ischemia based on their past experience; however, we have chosen three spells of 5 minutes period for limb ischemia with an intention to have a more pronounced effect of preconditioning. 7 In this study, we have found that the distribution of mean 48-hour post-operative VAS score at knee flexion is significantly higher compared to mean pre-operative VAS score at knee flexion (p<0.001). However, the distribution of mean preoperative and 6 th hour postoperative as well as preoperative and 24 th hour postoperative VAS score at knee flexion did not differ significantly (p>0.05 for both).…”

“…In the previous study the researchers have found median/IQR of fluid intake as 1700 ml/500 ml and tourniquet time 47.5 mins/13.3 mins in the preconditioning group. 7 This difference in result can be attributed to application of tourniquet till implantation of cemented components in their study, whereas in our study it has been applied till the end of surgery and application of compression dressings…”

“…In the above randomized study, however the total volume of epidural analgesics administered was 140.5±68.4 ml (preconditioning group) and 160.8±70.1 ml (control group) and authors couldn't observe any significant difference (p=0.432) in a total amount of epidural analgesic intake between two groups. 7 This difference in epidural intake can be attributed to different analgesics protocol followed in our study. In the aforementioned study, researchers have used both bupivacaine and hydromorphone via an epidural catheter in addition to intraoperative femoral nerve block.…”

“…In a prospective randomized study by Memtsoudis et al, with a total 60 patients (30 in the preconditioning group and 30 in the non-preconditioning group or control group) have found that there was a significant less postoperative pain in comparison to a control group. 7 However, in that study different strategy of limb preconditioning as well as different multimodal postoperative analgesia was used. They used only one 5 minute period of tourniquet inflation followed by release and patients also received intraoperative femoral nerve blocks with 0.25% bupivacaine and epinephrine in strength of 1:200,000.…”

“…5,6 However, the application of IPC in major orthopedic surgery like TKA is limited till date with very few studies studying the effect of ischemic preconditioning as a method of analgesia. 7,8 This study was undertaken with an aim to study the effect of ischemic preconditioning on post-operative pain relief in patients undergoing TKA by measuring patient reported pain score, postoperative requirement of analgesia, period required for ambulation along with duration of hospitalization.…”