Efficacy and Durability of Opioid Restrictive State Legislation Two Years After Implementation for Total Knee Arthroplasty.

BACKGROUND: To curtail the U.S. opioid crisis, many states have instituted regulations that mandate time and/or dosage limits for opioid prescriptions. This study evaluates the impact of one such law, Florida House Bill 21, on postoperative opioid prescribing patterns for patients undergoing total knee arthroplasty (TKA) and the durability of the law's impact over time. METHODS: All patients who underwent TKA at a single institution during the same three-month period in 2017 (pre-law), 2018 (post-law), and 2020 (2 years post-law) were identified. Outcomes and measures included: prescribed morphine milligram equivalents (MME) at discharge and for the 90-day surgical episode, refill quantity with associated MME, and quantity of opioid prescribers. Patients with established chronic pain or those who underwent contralateral TKA during the 90-day window were excluded. Data was compared using a one-way analysis of variance. Significance was set at alpha <0.05. RESULTS: The average MME of filled opioid prescriptions per patient during the 90-day post-surgical episode decreased from 1310 MME in 2017 to 891 MME in 2018 (P < .001). The average MME in 2020 was 814 MME, which was significantly lower than the average in 2017 (P < .001), and statistically stable compared to the average in 2018 (P = .215). CONCLUSION: Restrictive opioid state policy implementation was associated with reduced overall MME prescription to patients undergoing TKA at discharge and for the 90-day surgical episode. There was no increase in the number of opioid refills or opioid prescribers. Durable change and continued improvement were observed 2 years after implementation of law.