Nonbiologic Injections in Sports Medicine

Indocyanine green-mediated photothermal release of lidocaine from genipin-crosslinked gelatin hydrogel in nerve block

Local anesthetic (LA)-induced peripheral nerve block (PNB) is an important part of multimodal analgesia to reduce postoperative pain, accelerate postoperative recovery, and improve clinical prognosis. The duration of LA depends on anesthetics, and the repeated nerve positioning, puncture injection or indwelling catheter is often required to prolong the effect of PNB. In this study, the genipin, was used to crosslink gelatin-based hydrogel, and then co-loaded with indocyanine green (ICG) and lidocaine as an LA-controlled release system (ICG@Lido/Gel and ICG@Lido/gGel). The viscosity of the genipin-crosslinked gelatin hydrogel (gGel) could be controlled by the genipin/gelatin ratio to achieve the slow release of lidocaine. The ICG@Lido/Gel and ICG@Lido/gGel were biocompatible, and could reduce the instant concentration of lidocaine to minimize its direct cytotoxicity. The ICG@Lido/Gel and ICG@Lido/gGel could increase the PNB period to 70.8 min and 77.8 min, respectively. After NIR exposure, the PNB was introduced again and sustained to 20.8 min for ICG@Lido/Gel and 31.7 min for ICG@Lido/gGel. Therefore, the ICG@Lido/gGel could significantly prolong the PNB duration via increasing the residence time of lidocaine at the injection site, slowing the lidocaine release, and triggering the lidocaine release by NIR exposure. The ICG@Lido/gGel may expresses potential as a photothermal-triggered release system for PNB.

Intraarticular Injections in the Foot and Ankle: Medication Selection Patterns and Perceived Risk Of Chondrotoxicity

Background

Intraarticular corticosteroid injections (ICIs) are widely used to treat foot and ankle conditions. Although laboratory studies indicate certain corticosteroids and local anesthetics used in ICIs are associated with chondrotoxic effects, and selected agents such as ropivacaine and triamcinolone may have less of these features, clinical evidence is lacking. We aimed to identify the patterns of drug selection, perceptions of injectate chondrotoxicity, and rationale for medication choice among surgeons in the American Orthopaedic Foot & Ankle Society (AOFAS).

Methods

An e-survey including demographics, practice patterns, and rationale was disseminated to 2011 AOFAS members. Frequencies and percentages were calculated for demographic data, anesthetic and steroid choice, rationale for injectate choice, and perception of chondrotoxicity. Bivariate analysis was used to identify practice patterns significantly associated with perceptions of injectate risk and rationale.

Results

In total, 387 surveys were completed. Lidocaine and triamcinolone were the most common anesthetic and corticosteroid used (51.2% and 39.3%, respectively). Less than half of respondents felt corticosteroids or local anesthetics bear risk of chondrotoxicity. Respondents agreeing that corticosteroids are chondrotoxic were more likely to use triamcinolone (P = .037). Respondents agreeing local anesthetics risk chondrotoxicity were less likely to use lidocaine (P = .023). Respondents choosing a local anesthetic based on literature were more likely to use ropivacaine (P < .001).

Conclusion

Corticosteroid and local anesthetic use in ICIs varied greatly. Rationale for ICI formulation was also variable, as the clinical implications are largely unknown. Those who recognized potential chondrotoxicity and who chose based on literature were more likely to choose ropivacaine and triamcinolone, as reflected in the basic science literature. Further clinical studies are needed to establish guidelines that shape foot and ankle ICI practices based on scientific evidence and reduce the variation identified by this study.

Level of Evidence

Level IV, cross-sectional survey study.

One to Two Days of Rest Is Recommended Before Returning to Sport After Intra-Articular Corticosteroid Injection in the High-Level Athlete

Return to sport following a corticosteroid injection is a complex decision. Multiple considerations should be taken into account, including steroid dose and formulation, involvement of the affected joint in the activity, and intensity of the activity. Research investigating the adverse effects of corticosteroid injections with early initiation of high-intensity activity is limited and has produced mixed results. Rest following injections has typically been recommended to minimize both chondrotoxic effects and systemic absorption. Based on the current research and extensive experience treating professional athletes, we recommend 1 to 2 days of rest of the affected joint or region with a progressive increase of activity following a corticosteroid injection with possible benefits including maximizing the beneficial effects of the injection and a reduced systemic effect.

LEVEL OF EVIDENCE

Level V, expert opinion.

Effects of a natural nutritional supplement on immune cell infiltration and immune gene expression in exercise-induced injury

Inflammatory immune response plays a key role in exercise-induced injury and healing; however, the relevant regulatory mechanisms of immune infiltration in exercise-induced injuries remain less studied. In the present study, a highly efficient system for screening immunity-related biomarkers and immunomodulatory ability of natural nutritional supplements was developed by integrating intelligent data acquisition, data mining, network pharmacology, and computer-assisted target fishing. The findings demonstrated that resting natural killer cells showed a higher rate of infiltration after exercise, whereas naive B cells and activated dendritic cells showed higher rate of infiltration before exercise. Four key genes, namely PRF1, GZMB, CCL4, and FASLG, were associated with exercise-induced injuries and inflammatory immune response. In total, 26 natural compounds including echinacoside, eugenol, tocopherol, and casuariin were predicted by using the HERB databases. Molecular docking analysis showed that GZMB, FASLG, and CCL4 bound to echinacoside. In vivo experiments in mice showed that after 30 min swimming, natural killer (NK) cells showed high infiltration rates, and the key genes (GZMB, PRF1, FASLG, and CCL4) were highly expressed; however, echinocandin significantly reduced the level of NK cells and decreased the expression of the four key genes post exercise. This natural nutritional supplement may act to protect against inflammatory injury after exercise by suppressing specific immune infiltration.