Are Patients Taking Benzodiazepines at Increased Risk for Complications Following Primary Total Knee Arthroplasty?

Benzodiazepines are commonly taken by patients who are undergoing total knee arthroplasty (TKA), but there is a paucity of studies evaluating any associations. Therefore, we hoped to study if patients taking preoperative benzodiazepines would have increased complications following TKA.

Using a nationwide database, from 2010 to 2019, we evaluated patients undergoing primary TKA who either did or did not have a preoperative record of benzodiazepine prescription. We performed a multivariable logistic regression analysis, adjusting for multiple variables (age, gender, obesity, and Charlson comorbidity index), to determine the association of preoperative benzodiazepine use and adverse events in a matched cohort. Furthermore, we stratified patients by one vs multiple preoperative benzodiazepine prescription(s). We evaluated 90-day and 2-year rates of revision, resection, femur fracture fixation, manipulation under anesthesia (MUA), and delirium.

Patients filling more than one preoperative benzodiazepine prescription had increased adjusted odds of 90-day (odds ratio [OR] = 1.198, confidence interval [CI] = 1.086-1.320) and 2-year (OR = 1.188, CI = 1.125-1.254) revision; 90-day resection (OR = 1.430, CI = 1.125-1.817); 90-day (OR = 1.639, CI = 1.255-2.141) and 2-year (OR = 1.646, CI = 1.412-1.919) femur fracture fixation; and 2-year delirium (OR = 2.288, CI = 1.564-3.382). Preoperative benzodiazepine users had decreased adjusted odds of 90-day (OR = 0.670, CI = 0.639-0.702) and 2-year (OR = 0.702, CI = 0.671-0.734) MUA.

After controlling for multiple variables, benzodiazepine use was associated with increased rates of revision, resection, femur fracture fixation, and delirium. Furthermore, benzodiazepine use was also associated with a decreased rate of MUA. Orthopaedic professionals can counsel patients taking this group of medications about the associated adverse events. Future studies should assess the use of other muscle relaxants in the prevention of knee stiffness and MUA.