Multimodal pain protocols have reduced opioid requirements and decreased complications after elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). However, these protocols are not universally effective. The purposes of this study are to determine the risk factors associated with increased opioid requirements and the impact of preoperative narcotic use on the length of stay and inhospital complications after THA or TKA.
We prospectively evaluated a consecutive series of 802 patients undergoing elective primary THA and TKA over a 9-month period. All patients were managed using a multimodal pain protocol. Data on medical comorbidities and history of preoperative narcotic use were collected and correlated with deviations from the protocol.
Of the 802 patients, 266 (33%) required intravenous narcotic rescue. Patients aged <75 years (odds ratio [OR], 1.85; 95% confidence interval [CI], 1.10-3.12; P = .019) and with preoperative narcotic use (OR, 2.74; 95% CI, 2.01-3.75; P < .001) were more likely to require rescue. Multivariate logistic regression analysis demonstrated that preoperative narcotic use (OR, 2.74; 95% CI, 2.01-3.75; P < .001) was the largest independent predictor of increased postoperative opioid requirements. These patients developed more inhospital complications (OR, 1.92; 95% CI, 1.34-2.76; P < .001). This was associated with an increased length of stay (OR, 1.59; 95% CI, 1.06-2.37; P = .025) and a 2.5-times risk of requiring oral narcotics at 3 months postoperatively (OR, 2.48; 95% CI, 1.61-3.82; P < .001).
Despite the effectiveness of multimodal postoperative pain protocols, younger patients with preoperative history of narcotic use require additional opioids and are at a higher risk for complications and a greater length of stay.