Tapered Dose Postoperative Opioid Prescriptions Following Inpatient Total Hip and Knee Arthroplasty: Quality Improvement Study and Retrospective Review.

BACKGROUND: Overprescription of pain medications directly fuels the opioid epidemic. Veterans are profoundly impacted. Tapered dose protocols may reduce excessive prescribing. METHODS: A retrospective study of adult veterans who presented to our institution for primary total knee arthroplasty or total hip arthroplasty (THA) was performed. Postdischarge opioid use was reviewed before and after an opioid taper prescription protocol. The preprotocol and postprotocol groups had 299 and 89 veterans, respectively. Total Morphine Milligram Equivalent (MME) prescribed postdischarge, number of tablets prescribed, number of refills issued, 30-day emergency department visits, and 30-day readmissions were compared. Opioid naïve and chronic opioid users were both included. RESULTS: Preprotocol and postprotocol implementation group, in combination with surgery type (total knee arthroplasty versus THA) and opioid naïve status, predicted MME. On average, the postprotocol group received 224 MME less, THA patients received 177 MME less, and nonopioid naïve patients received 152 MME more. CONCLUSION: The opioid taper protocol led to less opioid administration after discharge. Taper protocols should be considered for postoperative pain management. LEVEL OF EVIDENCE: III, retrospective comparison study.

Functional recovery after peripheral nerve injury via sustained growth factor delivery from mineral-coated microparticles.

The gold standard for treating peripheral nerve injuries that have large nerve gaps where the nerves cannot be directly sutured back together because it creates tension on the nerve, is to incorporate an autologous nerve graft. However, even with the incorporation of a nerve graft, generally patients only regain a small portion of function in limbs affected by the injury. Although, there has been some promising results using growth factors to induce more axon growth through the nerve graft, many of these previous therapies are limited in their ability to release growth factors in a sustained manner and tailor them to a desired time frame. The ideal drug delivery platform would deliver growth factors at therapeutic levels for enough time to grow axons the entire length of the nerve graft. We hypothesized that mineral coated microparticles (MCMs) would bind, stabilize and release biologically active glial cell-derived neurotrophic factor (GDNF) and nerve growth factor (NGF) in a sustained manner. Therefore, the objective of this study was to test the ability of MCMs releasing growth factors at the distal end of a 10 mm sciatic nerve graft, to induce axon growth through the nerve graft and restore hind limb function. After sciatic nerve grafting in Lewis rats, the hind limb function was tested weekly by measuring the angle of the ankle at toe lift-off while walking down a track. Twelve weeks after grafting, the grafts were harvested and myelinated axons were analyzed proximal to the graft, in the center of the graft, and distal to the graft. Under physiological conditions in vitro, the MCMs delivered a burst release of NGF and GDNF for 3 days followed by a sustained release for at least 22 days. In vivo, MCMs releasing NGF and GDNF at the distal end of sciatic nerve grafts resulted in significantly more myelinated axons extending distal to the graft when compared to rats that received nerve grafts without growth factor treatment. The rats with nerve grafts incorporated with MCMs releasing NGF and GDNF also showed significant improvement in hind limb function starting at 7 weeks postoperatively and continuing through 12 weeks postoperatively when compared to rats that received nerve grafts without growth factor treatment. In conclusion, MCMs released biologically active NGF and GDNF in a sustained manner, which significantly enhanced axon growth resulting in a significant improvement of hind limb function in rats. The animal experiments were approved by University of Wisconsin-Madison Animal Care and Use Committee (ACUC, protocol# M5958) on January 3, 2018.