The impact of preoperative tramadol-only use on outcomes following total knee arthroplasty - Is tramadol different than traditional opioids?

BACKGROUND Opioid use prior to total knee arthroplasty (TKA) is known to have detrimental influence on postoperative outcomes. Whether or not the same is true for tramadol is currently unclear. The aim of this study was to clarify the relationship between preoperative tramadol and postoperative complications. METHODS The Truven Marketscan® Databases were used to conduct this retrospective cohort study. Patients undergoing primary TKA were identified and divided into cohorts based on preoperative medication status (i.e. opioid naive, tramadol-only, or non-tramadol opioids). Patient demographics, comorbidities, and 90-day outcomes were collected and compared between cohorts. Revision rates were analyzed at 1- and 3-years postoperatively. Univariate and multivariate analysis was performed. RESULTS 336,316 patients were included and 23,097 (6.9%) were preoperative tramadol-only users. Tramadol-only patients (v. opioid naive) had increased odds of 90-day readmission (OR-1.07, 95%CI 1.02-1.12, p = 0.004), wound complication (OR-1.13, 95%CI 1.01-1.27, p = 0.34), and 3-year revision rates (OR-1.35, 95%CI 1.19-1.53, p < 0.001). However, when compared to the preoperative opioid cohorts, tramadol-only patients had decreased odds of nearly all outcomes. Over the study period, the number of patients receiving preoperative opioids decreased while the proportion of patients prescribed tramadol-only increased. CONCLUSIONS While tramadol-only use has lower risk than traditional opioids, tramadol-only use preceding TKA is associated with increased rates of readmission, wound complication and revision surgery. This is important information for prescribers who may be using tramadol to treat symptomatic knee arthrosis prior to arthroplasty referral and for thought leaders producing clinical practice guidelines. LEVEL OF EVIDENCE Level III, Prognostic.