Postoperative Opioid Consumption is Greater after Simultaneous versus Staged Bilateral Total Knee Arthroplasty.

Increased exposure to opioids around total knee arthroplasty (TKA) can lead to a risk of long-term dependence. We hypothesized that performing simultaneous bilateral total knee arthroplasty (simBTKA) over staged surgery (staged bilateral total knee arthroplasty [stgBTKA]) may decrease the total amount of opiates used. We retrospectively reviewed 29 patients who underwent simBTKAs performed between February 2015 and November 2020 and identified 23 that did not use opioids ≤90 days prior to surgery. These were frequency matched for gender and body mass index to 50 stgBTKAs completed within 6 months who also were opioid-free ≤90 days prior to their first surgery. Using our state's prescription database, we reviewed postsurgery opioid refills and morphine milligram equivalents (MMEs) for the two groups and compared their initial MME prescription at discharge and their total MME consumption 6 months postoperatively. Total MME consumption for the stgBTKA group included all prescriptions following the first and 6 months after the second surgery, whereas for the simBTKA group, total consumption included the 6 months after their two same-day surgeries. The simBTKA group had more MMEs prescribed initially (median = 375) than did the stgBTKA group after second surgery (median = 300; p < 0.007), larger postoperative-refill MMEs in the first 30 days (median = 300) than stgBTKA (median = 0; p = 0.221) and increased total MME consumption 6 months after surgery (median = 675) compared with stgBTKA after second surgery (median = 450; p = 0.077). However, both groups had similar monthly consumptions rates, with medians I MMEs/month of 112 for simBTKA versus 96 for stgBTKA (p = 0.585). Our results suggest there is no significant difference in opioid consumption between simBTKA and stgBTKA. In fact, we found that simBTKA patients received larger opioid amounts in the immediate postoperative period as well as slightly larger amounts at 30 days.

Considerations in the Sickle Cell Patient Undergoing Hip Reconstructive Surgery.

Sickle cell disease (SCD) is a hemoglobinopathy that commonly has musculoskeletal effects including osteonecrosis of major joints (most often the hip) and medullary infarcts with resultant pain, functional limitations, and decreased quality of life. Patients with SCD may require surgical intervention, including total hip arthroplasty, frequently at a young age. The underlying pathologic process of SCD creates unique medical and surgical challenges that place these patients at increased risk of complications. This necessitates a multidisciplinary approach for providing surgical care to patients with SCD.

Influence of interfacial tryptophan residues on an arginine-flanked transmembrane helix.

The transmembrane helices of membrane proteins often are flanked by interfacial charged or aromatic residues that potentially help to anchor the membrane-spanning protein. For isolated single-span helices, the interfacial residues may be especially important for stabilizing particular tilted transmembrane orientations. The peptide RWALP23 (acetyl-GR2ALW(LA)6LWLAR22A-amide) has been employed to investigate the interplay between interfacial arginines and tryptophans. Here we replace the tryptophans of RWALP23 with A5 and A19, to investigate arginines alone with respect to helix fraying and orientation in varying lipid bilayers. Deuterated alanines incorporated into the central sequence allow the orientation and stability of the core helix to be assessed by means of solid -state 2H NMR in bilayers of DOPC, DMPC and DLPC. The helix tilt from the bilayer normal is found to increase slightly when R2 and R22 are present, and increases still further when the tryptophans W5 and W19 are replaced by alanines. The extent of helix dynamic averaging remains low in all cases. The preferred helix azimuthal rotation is essentially constant for all of the helices in each of the lipid membranes considered here. The alanines located outside of the core region of the peptide are sensitive to helical integrity. The new alanines, A5 and A19, therefore, provide new information about the length of the core helix and the onset of unraveling of the terminals. Residue A19 remains essentially on the central helix in each lipid membrane, while residues A3, A5 and A21 deviate from the core helix to an extent that depends on the membrane thickness. Differential unraveling of the two ends to expose peptide backbone groups for hydrogen bonding therefore acts together with specific interfacial side chains to stabilize a transmembrane helix.