Cryar KA, et al. - Authors ascertained the risk factors leading to increased narcotic use following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Findings suggested a correlation of patient’s pre-operative narcotic, tramadol, benzodiazepine, and tobacco use and the amount of postoperative narcotic prescriptions filled in the 3 months following surgery. A characteristic factor was noted to be the predisposition to substance abuse which led to increased post-operative narcotic use.