Nanotechnology for pain management in orthopedic surgery

This narrative review evaluated the potential of nanotechnology platforms (DepoFoam bupivacaine^®, DepoDur^®, Exparel^®, Zynrelef^®, NeuroCuple^™) in the control of postoperative pain following orthopedic procedures. In individuals experiencing bunionectomy DepoFoam bupivacaine^® 120 mg and placebo <i>via</i> wound infiltration before wound closure was compared. The area under the curve for numeric rating scale scores was substantially less in individuals treated with DepoFoam bupivacaine^® <i>vs</i> individuals receiving placebo at 24 h and 36 h. In individuals undergoing total hip arthroplasty, a single dose of 15 mg, 20 mg, or 25 mg DepoDur^® [extended-release epidural morphine (EREM)] and placebo were compared. All EREM dosages diminished the mean fentanyl usage <i>vs</i> placebo and delayed the median time to first dose of fentanyl. All EREM cohorts had substantially improved pain control at rest for up to 48 h post-surgery compared with placebo. No supplementary analgesia was required in 25% of individuals treated with EREM and 2% of individuals treated with placebo at 48 h. In individuals undergoing total knee arthroplasty, iPACK (local anesthetic infiltration of the interspace between the popliteal artery and the posterior knee capsule) adductor canal block was compared to adductor canal block with Exparel^®. Individuals in the Exparel^® cohort experienced an improvement in numeric rating scale pain scores at all postsurgical time points. These individuals also utilized a lower dose of inpatient opioids. In individuals undergoing bunionectomy a single intraoperative dose of Zynrelef^® prolonged release (PR) was compared to bupivacaine HCl 0.5% <i>via</i> wound infiltration before wound closure. Zynrelef^® PR diminished pain intensity by 18% compared with bupivacaine HCl. Opioid consumption was reduced by 37% in the Zynrelef^® PR cohort <i>vs</i> 25% in the bupivacaine HCl cohort. In individuals experiencing total knee arthroplasty and total hip arthroplasty, the use of a nanotechnology-based NeuroCuple^TM device diminished postoperative pain at rest by 34% and reduced pain with movement by 18%.