Synovial mesenchymal stem cells secrete more lubricin than adipose mesenchymal stem cells after injection into rat osteoarthritis knees.

Intra-articular injection of mesenchymal stem cells (MSCs) is envisioned as a solution for knee osteoarthritis (OA). Although synovial MSCs (SyMSCs) are promising for cartilage regeneration, the clinical choice is usually adipose MSCs (AdMSCs). However, the similarities/differences in the mode of action between SyMSCs and AdMSCs remain unclear. Here, we compared factors secreted by human SyMSCs and AdMSCs after injection into OA knees. Human SyMSCs or AdMSCs were injected into the knees of rat partial meniscectomy models. The next day, the knee joints were collected to analyze the distribution of injected MSCs and transcriptome changes in the human MSCs and rat synovium. Non-injected MSCs were mixed with rat synovium as a control. After injection, no difference was apparent in intra-articular distribution of the SyMSCs or AdMSCs. RNA sequencing demonstrated an enrichment of cytokine-cytokine receptor interaction-related genes in both human SyMSCs and AdMSCs after injection. Differentially expressed genes (DEGs) specific to SyMSCs were associated with cartilage matrix synthesis and homeostasis. PCR analysis of the matrisome-related DEGs showed significantly higher expression of PRG4 in SyMSCs than in AdMSCs after injection. Immunostaining also confirmed a significantly greater expression of lubricin by SyMSCs than by AdMSCs. These findings indicate that SyMSCs will be a more promising treatment for OA.

ECM-mimetic, NSAIDs loaded thermo-responsive, immunomodulatory hydrogel for rheumatoid arthritis treatment.

BACKGROUND: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease, and it leads to irreversible inflammation in intra-articular joints. Current treatment approaches for RA include non-steroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), corticosteroids, and biological agents. To overcome the drug-associated toxicity of conventional therapy and transdermal tissue barrier, an injectable NSAID-loaded hydrogel system was developed and explored its efficacy. RESULTS: The surface morphology and porosity of the hydrogels indicate that they mimic the natural ECM, which is greatly beneficial for tissue healing. Further, NSAIDs, i.e., diclofenac sodium, were loaded into the hydrogel, and the in vitro drug release pattern was found to be burst release for 24 h and subsequently sustainable release of 50% drug up to 10 days. The DPPH assay revealed that the hydrogels have good radical scavenging activity. The biocompatibility study carried out by MTT assay proved good biocompatibility and anti-inflammatory activity of the hydrogels was carried out by gene expression study in RAW 264.7 cells, which indicate the downregulation of several key inflammatory genes such as COX-2, TNF-α & 18s. CONCLUSION: In summary, the proposed ECM-mimetic, thermo-sensitive in situ hydrogels may be utilized for intra-articular inflammation modulation and can be beneficial by reducing the frequency of medication and providing optimum lubrication at intra-articular joints.

The utility of standing knee radiographs for detection of lipohemarthrosis: comparison with supine horizontal beam radiographs.

OBJECTIVES: Lipohemarthrosis is a key finding in acute trauma patients and indicates an intra-articular fracture. The horizontal beam lateral radiography with supine position is known to be the best technique to demonstrate knee lipohemarthrosis. Our main purpose was to compare the sensitivity of supine and standing lateral knee radiographs to detect lipohemarthrosis. METHODS: In our retrospective study, consecutive patients with lipohemarthrosis on computed tomography of the knee between October 2019 and September 2021 were included. Fractured bone, the presence of lipohemarthrosis, and image quality in both standing and supine anteroposterior and lateral knee radiographs were evaluated. Interobserver reliability of the three observers was calculated. Fisher exact chi-square and z-proportion tests were used to compare lateral and anteroposterior knee radiographs. Krippendorff's Alpha and Kappa coefficients were used for inter-observer agreement. RESULTS: A total of 61 patients (38 men [62.3%], 23 women [37.7%]; mean age, 43 years ± 17 [standard deviation]) were included. The most common type of fracture was isolated tibial fractures (n = 32; 52.5%). The sensitivity of showing lipohemarthrosis of standing lateral knee radiographs (95.5%) was higher than supine lateral radiographs (38.5%) (p < 0.001). While non-optimal image quality did not affect lipohemarthrosis detection on lateral radiographs (p > 0.99), it caused a significant decrease in the diagnosis of lipohemarthrosis on anteroposterior radiographs (p = 0.036). We found a good-excellent interobserver agreement in lipohemarthrosis detection. CONCLUSIONS: Standing lateral radiographs have higher sensitivity than supine lateral radiographs in detecting lipohemarthrosis and are beneficial for detecting lipohemarthrosis which indicates the presence of occult-evident intraarticular fracture in patients with knee trauma. CLINICAL RELEVANCE STATEMENT: Standing lateral knee radiographs offer a useful method for reducing the misdiagnosis of the occult intra-articular fractures by showing the fat-fluid leveling more clearly. Its advantages may be more prominent when the advanced imaging modalities are limited. KEY POINTS: • Fat-fluid level (lipohemarthrosis) is an important radiographic sign to assess patients with acute trauma. It almost always indicates an intra-articular fracture. • Our retrospective study results support that lipohemarthrosis sign could be observed more frequently in standing lateral knee radiographs than in supine lateral radiographs. • Knee trauma patients, when available, should be evaluated with standing lateral radiographs for the diagnosis of lipohemarthrosis.

Toll-like receptor activation regulates the paracrine effect of adipose-derived mesenchymal stem cells on reversing osteoarthritic phenotype of chondrocytes.

BACKGROUND: The therapeutic efficacy of intra-articular mesenchymal stem cells (MSCs) injection for patients with osteoarthritis (OA) currently exhibits inconsistency, and the underlying mechanism remains elusive. It has been postulated that the immunomodulatory properties and paracrine activity of MSCs might be influenced by the inflammatory micro-environment within osteoarthritic joints, potentially contributing to this observed inconsistency. METHODS: Adipose-derived MSCs (ADSCs) were isolated from SD rats and pre-treated with Toll-like receptor 3 (TLR3) agonist Poly I:C or Toll-like receptor 4 (TLR4) agonist LPS. The pre-treated ADSCs were then co-cultured with IL-1ß-induced osteoarthritic chondrocytes using a Transwell system to analyze the paracrine effect of ADSCs on reversing the osteoarthritic phenotype of chondrocytes. RESULTS: RT-PCR and Western blot analysis revealed that Poly I:C and LPS pre-treatments up-regulated the expression of IL-10 and IL-6 in ADSCs, respectively. Furthermore, only Poly I:C-preconditioned ADSCs significantly promoted proliferation while inhibiting apoptosis in IL-1ß-treated chondrocytes. Additionally, Poly I:C-preconditioned ADSCs downregulated MMP13 expression while upregulating aggrecan and collagen II expression levels in IL-1ß-treated chondrocytes. CONCLUSIONS: TLR3 activation polarizes ADSCs into an immunomodulatory phenotype distinct from TLR4 activation, exerting differential effects on reversing the osteoarthritic phenotype of chondrocytes; thus indicating that MSCs' paracrine effect regulated by TLRs signaling impacts the efficacy of intra-articular MSCs injection.

Rotator Interval vs Posterior Approach Ultrasound-guided Corticosteroid Injections in Primary Frozen Shoulder: A Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: To compare the efficacy of rotator interval (RI) vs posterior approach (PA) ultrasound (US) guided corticosteroid injections into the glenohumeral (GH) joint in primary frozen shoulder (PFS). DATA SOURCES: A systematic literature search for all relevant studies on Medline, Scopus, Embase, Web of Science, and Cochrane Central, up to January 2023 was conducted. STUDY SELECTION: Randomized controlled trials that directly compared the US-guided corticosteroid injection into the RI and GH joint using PA in patients clinically and radiographically diagnosed with PFS. DATA EXTRACTION: The primary outcome was pain, and the secondary outcomes were function, and range of motion (ROM). Two authors independently assessed the risk of bias using the Cochrane risk-of-bias tool version 2. A random-effects model and generic inverse variance method were performed. Effect sizes were estimated using mean difference (MD) and standardized mean difference (SMD). DATA SYNTHESIS: A total of 5 clinical trials involving 323 subjects were included for the meta-analysis. US-guided corticosteroid injections into the RI revealed significant pain relief (MD 1.33 [95% confidence interval (CI) 0.20 to 2.46]; P=.02) and significant functional improvement (SMD 1.31 [95% CI 0.11 to 2.51]; P=.03) compared with the PA after 12 weeks. CONCLUSION: The results suggest the injection of corticosteroid into RI space is more effective than PA after 12 weeks in improving both pain and functional scores in patients with PFS.

Evaluation of single and multiple hyaluronic acid injections at different concentrations with high molecular weight in the treatment of knee osteoarthritis.

BACKGROUND: Knee osteoarthritis is severe progressive and most commonly diagnosed articular disease and its incidence is increasing around the world depending on age. This pathologic condition which limits daily activity of patients can be characterized by degeneration of cartilage and inflammation. Although non-steroidal anti-inflammatory (NSAII) agents and other analgesics are routinely used treatment options, the potential effects of intraarticular injections including hyaluronic acid (HA) have also been demonstrated by various studies. However, few studies compare the efficacy of a single high molecular weight (HMW) high dose and a triple HMW low dose. This study aimed to compare the efficacy of single high molecular weight (HMW) high dose (2 mL / 60 mg) and triple HMW low dose (2 mL /30 mg) intra-articular injection of HA in knee osteoarthritis (OA) patients by evaluating function and pain parameters during 12 months. METHODS: This is a single-center, retrospective clinical study that included and involved 128 patients. Group I (n=64) patients received triple 30 mg HA injections (SEMICAL®) with one-week intervals, while Group II (n=64) patients received a single 60 mg HA injection (SEMICAL®). Lequesne Index, WOMAC and VAS scores were recorded to assess pain and function during a 12-month period. RESULTS: There was no significant difference in characteristics of patient demographics. Our finding indicate that WOMAC, VAS score, and Lequesne Index values during follow-up visits exhibited a decrease, signifying improvement in the clinical condition. Notably, scores were significantly more favorable with the 30 mg of HA injection compared to the 60 mg of HA injection. CONCLUSION: This study suggests that the triple low-dose injection of HMW HA is more effective in improving WOMAC, VAS scores and Lequesne Index values than a single high-dose injection.

The necessity of suction drainage when intra-articular injection of tranexamic acid is used during primary total knee arthroplasty: a retrospective study.

BACKGROUND: Suction drainages are commonly used after total knee arthroplasty (TKA) procedures; however, their use is somewhat controversial. Recently, some reports have claimed that the administration of tranexamic acid (TXA) may prevent postoperative bleeding following TKAs. Although numerous studies have reported regarding different dosages, timings of administration, or drain clamping times for intravenous and intra-articular TXA injections (IA-TXAs), few have examined whether suction drainage is necessary when TXA is administered. In this study, we compared using suction drainage without TXA administration and IA-TXA without suction drainage and aimed to examine the need for suction drainage during IA-TXA. METHODS: This retrospective study was conducted on 217 patients who had received TKA for osteoarthritis; 104 were placed on suction drainage after TKA without TXA (Group A), whereas the remaining 113 received IA-TXA immediately after surgery without suction drainage (Group B). Our clinical evaluation included assessments of the need for transfusion, presence of postoperative complications, incidence of deep vein thrombosis (DVT), and changes in hemoglobin (Hb), hematocrit (Hct), and D-dimer levels. RESULTS: No significant differences were observed in terms of postoperative complications and preoperative Hb, Hct, or D-dimer levels between the two groups. Although the prevalence of DVT was significantly higher in Group B (p < 0.05), all cases were asymptomatic. Hb and Hct levels were significantly lower in Group A than in Group B at 1, 3, 7, and 14 days postoperatively (p < 0.05), although none of the cases required blood transfusions. D-dimer levels were significantly higher in Group A than in Group B at 1 and 3 days postoperatively (p < 0.05). CONCLUSION: Suction drainage might not be necessary when IA-TXA is administered after TKA procedures.

Intra-articular injection of gold micro-particles with hyaluronic acid for painful knee osteoarthritis.

BACKGROUND: Recently, in an open pilot study, we found up to two years, a potential pain-relieving effect of intra-articular gold micro-particles using the patient's synovial fluid for patients with knee osteoarthritis (KOA). During the study the excluded group of patients, due to multisite pain, co-morbidities, and other exclusion criteria., received intra-articular gold micro-particles using hyaluronic acid,. We aimed to identify if pre-treatment characteristics influence the global outcome two years after intra-articular treatment for painful KOA with gold microparticles using hyaluronic acid. METHODS: Using hyaluronic acid as the carrier, 136 patients with KOA received intraarticular injections with 20 mg gold microparticles (72.000 particles, 20-40 µm in diameter). In the analysis, we included the Global Rating of Change Scale, Pain Detect Questionnaire (PDQ), Body Mass Index (BMI), and Kellgren & Lawrence score at the inclusion, Western Ontario, and McMaster Universities Osteoarthritis Index (WOMAC) sub-scores for pain, stiffness, and function at inclusion and two years. RESULTS: On the Global Rating Change Scale, 69.1% of patients reported a positive effect, 28.7% no effect, and 2.2% worse. PDQ and the three WOMAC subscores all improved at two years of follow-up. PDQ ≥ 13 (P = 0.028), BMI (P = 0.022) and Kellgren & Lawrence grade 4 (P = 0.028) at inclusion reduced the effect with a minor odds ratio compared to the baseline effect of treatment (P = 0.025). WOMAC subscores at inclusion did not influence the outcome (P > 0.5). CONCLUSIONS: Severe osteoarthritis, obesity, and neuropathic pain, reduced the effect of intra-articular gold microparticles for knee OA. TRIAL REGISTRATION: The study followed the principles of the Declaration of Helsinki and was approved by the local ethics committee of the North Denmark Region by 27/07/2016 (N-20,160,045). The regional data protection agency approved the project by 06/07/2016 (2008-58-0028, ID 2016 - 116) and registered in ClinicalTrial.Gov by 04/01/2018 (NCT03389906).

Pathology of intra-articular tumours and tumour-like lesions: pearls, pitfalls and rarities from a general surgical pathology practice.

Intra-articular tumours are uncommonly encountered in routine practice and may present diagnostic challenges to pathologists. Challenges unique to this site include distinction from more common reactive synovial conditions, which are far more common; histologic variability; superimposed reactive changes; and often, lack of provided clinicoradiological context. This article reviews the pathology of the synovial tumours and tumour-like lesions, including diagnostic pearls, pitfalls and rare entities.

Two-dimensional liquid chromatography measurement of meropenem concentration in synovial fluid of patients with periprosthetic joint infection.

Periprosthetic joint infection (PJI) is a catastrophic complication following joint replacement surgery. One potential treatment approach for PJI could be the combination of one-stage revision and intra-articular infusion of antibiotics. Meropenem is one of the commonly used intra-articular antibiotics in our institution. Determining the concentration of meropenem in the joint cavity could be crucial for optimizing its local application, effectively eradicating biofilm infection, and improving PJI treatment outcomes. In this study, we developed a simple, precise, and accurate method of two-dimensional liquid chromatography (2D-LC) for determining the concentration of meropenem in human synovial fluid. The method was then validated based on the guidelines of the Food and Drug Administration and the Chinese Pharmacopoeia. Meropenem showed good linearity in the range of 0.31-25.01 µg/mL (r ≥ .999). Selectivity, intra-day and inter-day precision and accuracy, extraction recovery, and stability validation results were all within the acceptance range. This method has been successfully applied to the determination of synovial fluid samples from PJI patients, providing a useful detection method for meropenem therapeutic drug monitoring (TDM) in PJI patients.

Adding Dexmedetomidine to Intra-articular Local Anesthetics Results in Prolonged Analgesia after Knee Arthroscopy: A Systematic Review and Meta-Analysis.

PURPOSE: This systematic review and meta-analysis aims to assess the efficacy and safety of dexmedetomidine as an adjuvant to intra-articular (IA) injections of local anesthetics (LA) in adult patients undergoing knee arthroscopy. METHODS: We searched MEDLINE, Embase, and Cochrane Library for randomized controlled trials (RCTs) comparing IA dexmedetomidine plus LA versus LA alone for knee arthroscopy in adults. We used the DerSimonian and Laird random-effects model for all outcomes, and conducted a sensitivity analysis with the leave-one-out method, as well as a subgroup analysis for the type of LA. We used R version 4.1.2 for all statistical analyses. RESULTS: We included 16 RCT encompassing 799 patients, of whom 49.8% received IA dexmedetomidine. In the pooled analysis, time to first analgesia rescue was prolonged in almost 4 hours with the use of dexmedetomidine (MD 229 min; p<0.001). We found statistically significant differences favoring dexmedetomidine in pain scores at rest and movement throughout the first 2, 6, 12 and 24 hours postoperatively (p<0.001). Although the mean difference (MD) ranged from -0.3 to -0.9 cm, corresponding to a 3 to 9% reduction in pain scores, this change is not clinically significant when compared to the minimal clinically important difference (MCID). Additionally, the intervention group showed a statistically significant reduction in cumulative opioid consumption over 24 hours (MD -4.5 mg; p<0.001). However, this reduction did not meet the threshold for the MCID. There was no difference between groups on the incidence of hypotension (p=0.190), bradycardia (p=0.430) and postoperative nausea and vomiting (p=0.550). CONCLUSIONS: Adding dexmedetomidine to LA in IA injections for knee arthroscopy significantly extended analgesia duration. Additionally, it lowered pain scores and opioid use, although these effects did not reach the MCID. Furthermore, this addition did not increase the risk of adverse events.

Mesenchymal stem cells injection is more effective than hyaluronic acid injection in the treatment of knee osteoarthritis with similar safety: systematic review and meta-analysis.

PURPOSE: To evaluate the Efficacy and safety of intra-articular injection of mesenchymal stem cells (MSCs) versus Hyaluronic acid (HA) in the treatment of knee osteoarthritis (KOA). METHODS: Eligible randomized controlled trials (RCTs) were identified through a search of Pubmed, Embase, the Cochrane Library, Web of science, SinoMed and CNKI databases from inception to March 2024. For meta-analysis, data on clinical outcomes were measured using a visual analog scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and data on cartilage repair were measured using the Whole-Organ Magnetic Resonance Imaging Score (WORMS); data on safety was evaluated by the incidence of adverse events. Two researchers independently read the included literatures, extracted data and evaluated the quality, and used Cochrane risk bias assessment tool for bias risk assessment, and RevMan5.3 software for Meta-analysis. RESULT: Ten RCTs involving 818 patients with KOA ranging from I-Ⅲ Kellgren - Lawrence grading scale were included in this meta-analysis. Meta results showed that compared with the HA control group, at 12months, the WOMAC total score ［MD=-10.22, 95% CI (-14.86∼-5.59), P<0.0001, Z=4.32］;VAS score［MD=-1.31, 95% CI (-1.90∼-0.73), P<0.0001, Z=4.40］; WORMS score ［MD=-26.01,95% CI （-31.88∼-20.14）,P<0.001,Z=8.69］of MSCs group all decreased significantly (P<0.05), and reached the minimum clinically important differences (MCID). Furthermore, there was no significant difference in the incidence of adverse events (RR=1.54, 95% CI= 0.85 ∼ 2.79, P=0.16, I2=0) between the two groups (P >0.05). CONCLUSION: Compared to HA, intra-articular injection of MSCs therapy appears to effectively alleviate joint pain, improve clinical function of KOA patients. These benefits are observed to last for at least 12 months without an increase in adverse events. Due to limited, varied, and lacking MCID results in existing literature，further research is needed. LEVEL OF EVIDENCE: Level I, Meta-analysis of Level I studies.

Intra-articular corticosteroid injections provide a clinically relevant benefit compared to placebo only at short-term follow-up in patients with knee osteoarthritis: A systematic review and meta-analysis.

PURPOSE: To quantify the clinical relevance of intra-articular corticosteroid effects compared to placebo for the injective treatment of knee osteoarthritis (OA). METHODS: The PubMed, Cochrane Library and Web of Science databases were searched on May 3, 2023. This study was conducted in accordance with the PRISMA guidelines. The inclusion criteria were randomized controlled trials (RCTs), published in English, with no time limitation regarding publication date, comparing intra-articular corticosteroids and placebo injections for knee OA. The effects were quantified at short- (≤6 weeks), mid- (>6 weeks and ≤3 months), and long-term (≥6 months) follow-ups. The minimal clinically important difference (MCID) for the outcomes (visual analogue scale for pain - VAS: 1.4, Western Ontario and McMaster University Osteoarthritis Index - WOMAC: 9) was used to interpret the clinical improvement provided by intra-articular corticosteroid injections compared to placebo. The quality of each article was assessed using the Cochrane RoB 2 tool and the GRADE guidelines. RESULTS: Among the 1030 articles retrieved, 11 RCTs (842 patients) were included. A comparison of the two groups revealed statistically significant differences in the improvement of VAS and WOMAC scores in terms of the mean difference (MD); this difference was in favour of corticosteroids at short-term (p < 0.001, MD = -1.6 and p < 0.001, MD = -9.9, respectively) and mid-term follow-ups (p = 0.001, mean MD = -1.3 and p = 0.005, MD = -4.9, respectively). No difference was observed at the long-term follow-up. The MDs between the improvements in the two groups reached the MCID values for the VAS and WOMAC only at the short-term follow-up. The RoB 2 tool and the GRADE evaluations showed the presence of risk of bias and limited quality of evidence. CONCLUSION: This systematic review and meta-analysis demonstrated that intra-articular corticosteroid injections offer clinically perceivable pain relief and functional improvement higher than the placebo effect only at short-term follow-up in patients affected by knee OA, with benefits losing clinical relevance already after 6 weeks. These results, together with the low number and the limited quality of the RCTs comparing this treatment with placebo, question the indication for the use of corticosteroid injections in clinical practice for the treatment of knee OA. LEVEL OF EVIDENCE: Level I.

Efficacy of Intra-Articular Corticosteroid Injection for Nonsurgical Management of Trapeziometacarpal Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PURPOSE: As osteoarthritis (OA) of the trapeziometacarpal (TMC) joint leads to a high degree of disease burden with compromises in rudimentary and fine movements of the hand, intra-articular injections may be a desirable treatment option. However, because there are no evidence-based guidelines, the choice of intra-articular injection type is left to the discretion of the individual surgeon in collaboration with the patient. The purpose of our study was to perform a systematic review and meta-analysis using level I studies to compare outcomes following corticosteroid and alternative methods of intra-articular injections for the management of TMC OA. Our hypothesis was that intra-articular corticosteroid injections were no more effective than other methods of intra-articular injections for the management of TMC OA. METHODS: A systematic literature search was performed. Eligible for inclusion were randomized control trials reporting on intra-articular corticosteroid injection for the management of TMC OA. Clinical outcomes were recorded. RESULTS: The 10 included studies comprised 673 patients. The mean age was 57.8 ± 8.3 years, with a mean follow-up of 6.4 ± 2.7 months. There was no significant difference in visual analog scale scores, grip strength and tip pinch strength between corticosteroids and hyaluronic acid at short- and medium-term follow-up. Further, there was no difference in visual analog scale pain scores at rest at medium-term follow-up between corticosteroids and platelet-rich plasma. CONCLUSIONS: Despite short-term improvement with intra-articular corticosteroid injections, there was no significant difference in pain and functional outcomes following intra-articular corticosteroid injections compared to hyaluronic acid or platelet-rich plasma administration. Given the affordability, ease of administration, and efficacy associated with corticosteroids, they are a favorable option when considering the choice of intra-articular injection for the management of TMC OA. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Analgesic Techniques for Managing Orthopedic Injuries: A Review for the Emergency Clinician.

BACKGROUND: Orthopedic injuries are commonly managed in the emergency department (ED) setting. Fractures and dislocations may require reduction for proper management. There are a variety of analgesic and sedative strategies to provide patient comfort during reduction. OBJECTIVE: This narrative review evaluates hematoma block, intra-articular injection, intravenous regional analgesia (IVRA) (also known as the Bier block), and periosteal block for orthopedic analgesia in the ED setting. DISCUSSION: Analgesia is an essential component of management of orthopedic injuries, particularly when reduction is necessary. Options in the ED setting include hematoma blocks, intra-articular injections, IVRA, and periosteal blocks, which provide adequate analgesia without procedural sedation or opioid administration. When used in isolation, these analgesic techniques decrease complications from sedation and the need for other medications, such as opioids, while decreasing ED length of stay. Emergency clinicians can also use these techniques as analgesic adjuncts. However, training in these techniques is recommended prior to routine use, particularly with IVRA. CONCLUSIONS: Knowledge of analgesic techniques for orthopedic procedures can assist clinicians in optimizing patient care.

A novel configuration for the fixation of intra-articular C2.3 distal humerus fractures with the potential for minimally invasive surgery: a biomechanical evaluation and finite element analysis.

BACKGROUND: Distal humerus fractures are a challenge to treat, and the current standard of care, open reduction internal fixation with a double-plate, has a high rate of complications. We proposed a novel internal fixation configuration, lateral intramedullary nail and medial plate (LINMP) and verified its rigidity through biomechanical tests and finite element analysis. METHODS: The study involved biomechanical testing of 30 synthetic humerus models to compare 2 different fixation systems for an AO 13C-2.3 type fracture. The orthogonal double-plate (ODP) group and the LINMP group were compared through biomechanical testing to measure stiffness and failure load fewer than 3 working conditions. Based on the results, we optimized the intramedullary nail by eliminating the holes at the distal end of the nail and incorporating a 2-hole external locking plate. The Finite element analysis was also conducted to further compare the modified LINMP configuration with the previous 2 fixation configurations. RESULTS: In biomechanical tests, the ODP group exhibited lower stiffness under bending and compression forces compared to the LINMP group, but higher stiffness and failure loads under torsion force. In finite element analysis, the modified LINMP reduces the maximum stress of the fixation structure without significantly reducing the stiffness under bending stress and axial compression conditions. In torsion stress conditions, the modified LINMP enhances both the maximum stress and the stiffness, although it remains marginally inferior to the ODP structure. CONCLUSION: Our study demonstrates that the innovative LINMP presents comparable or slightly superior concerning bending and axial loading compared to orthogonal double-plate osteosynthesis for distal humeral intra-articular fractures, which might become a minimally invasive option for these fractures.

Role of Preoperative Intra-Articular Corticosteroid Injections on Periprosthetic Joint Infection in Total Hip Arthroplasty and Its Association With Preoperative Timing: A Single-Center Series of 5,909 Hips.

BACKGROUND: Preoperative intra-articular corticosteroid injections to the hip joint increase the risk of periprosthetic joint infection (PJI) during primary total hip arthroplasty (THA). This study aimed to determine the relationship between preoperative timing of intra-articular corticosteroid injections and PJI risk following THA using data from a single-center hospital. METHODS: This single-center, retrospective cohort study included patients who underwent a THA between 2014 and 2020. Medical records were checked for intra-articular corticosteroid injections and PJI within 1 year of surgery. Patients were categorized into groups based on whether they received "no injection" or "injection 0 to 3 months," "3 to 6 months," and "> 6 months prior to THA." Hazard ratios (HRs) for these groups were calculated using multivariate Cox regression analysis, correcting for potential confounders, and presented with 95% confidence intervals [95% CIs]. RESULTS: In total, 4,507 patients (5,909 THAs) were identified. A total of 1,581 patients (27%) received an injection prior to THA. Without considering the timing factor, no increased risk for PJI following an intra-articular injection was noted (P = .19). Comparing the specified groups using multivariate analysis, corticosteroid injection within 3 months of THA showed an increased risk of PJI (HR 2.63, 95% CI 1.18 to 5.87, P = .018), but this effect was not observed for the "injection 3 to 6 months" group (HR 1.51, 95% CI 0.74 to 3.08, P = .264). CONCLUSIONS: Corticosteroid injections administered up to 3 months prior to THA increased the risk of PJI within 1 year after THA, with an HR of 2.63; however, injections between 3 and 6 months before surgery did not have a significantly higher infection rate.

Extended-Release Versus Immediate-Release Triamcinolone Acetonide in Patients Who Have Knee Osteoarthritis and Type 2 Diabetes Mellitus.

BACKGROUND: Intra-articular corticosteroid injections may cause hyperglycemia (glucose level >180 mg/dL). In a phase 2 study of 33 patients who had osteoarthritis of the knee and type 2 diabetes mellitus, triamcinolone acetonide extended-release (TA-ER) was associated with minimal glycemic control disruption compared with triamcinolone acetonide immediate-release (TA-IR). This post hoc analysis characterizes the clinical relevance of these results. METHODS: Patients who had symptomatic osteoarthritis of the knee for ≥6 months, type 2 diabetes mellitus for ≥1 year, and hemoglobin A1c ≥6.5 and ≤9.0% were randomized to receive an intra-articular injection of either TA-ER or TA-IR. Changes in continuous glucose monitor daily glucose level, percentage of time in or above the target glucose range (>70 to 180 mg/dL), time to glucose level 250 mg/dL and maximum glucose level >250 mg/dL, and glycemic variability were evaluated. RESULTS: Across postinjection days 1 to 3, the TA-ER group (n = 18) had a lower median change from baseline in maximum glucose level (92.3 versus 169.1 mg/dL), a reduced percentage of time with a glucose level >250 mg/dL (12 versus 26%), a smaller proportion of patients who had a maximum glucose level >250 mg/dL (50 versus 93%), and a greater percentage of time in the target glucose range (62 versus 48%) versus the TA-IR group (n = 15). There was less glycemic variability and lower glucose spikes in the TA-ER versus TA-IR group. Median times to glucose level 250 mg/dL (44 versus 6 hours) and maximum glucose level (34 versus 13 hours) were significantly longer in the TA-ER versus TA-IR group. CONCLUSIONS: Use of TA-ER was associated with a clinically meaningful reduction in hyperglycemia versus TA-IR.

Improved Pain and Function With Triamcinolone Acetonide Extended-Release and Cryoneurolysis for Knee Osteoarthritis: Use of a New Real-World Registry.

BACKGROUND: Knee osteoarthritis (OA) affects 19% of American adults aged more than 45 years and costs $27+ billion annually. A wide range of nonoperative treatment options are available. This study compared 6 treatments: cryoneurolysis with deep genicular nerve block (Cryo-Deep/Both), cryoneurolysis with superficial nerve block (Cryo-Superficial), intra-articular hyaluronic acid (IA-HA) injections, nonsteroidal anti-inflammatory drug injections (IA-NSAIDs), IA-corticosteroids (IA-CS) injections, or IA-triamcinolone extended release (IA-TA-ER) injections over 4 months for: (1) pain severity and analgesic use; and (2) physical function (from Knee Injury and Osteoarthritis Outcome Score for Joint Replacement). METHODS: Patients who had unilateral knee OA and received nonoperative intervention were enrolled in the Innovations in Genicular Outcomes Research registry, a novel, multicenter real-world registry, between September 2021 and February 2024. A total of 480 patients were enrolled. Both pain and functional outcomes were assessed at baseline, weekly, and monthly, which were analyzed by overall trend, magnitude changes pretreatment to post-treatment, and distribution-based minimally clinically important difference (MCID) score. Multivariate linear regressions with adjustments for 7 confounding factors were used to compare follow-up outcomes among 6 treatment groups. RESULTS: Use of IA-TA-ER injections was associated with the lowest pain, greatest pain reduction, and highest prevalence of patients achieving MCID relative to other treatments (P < .001). Deep/Both-Cryo and IA-CS were associated with a higher prevalence of achieving MCID than IA-HA, IA-NSAIDs, and Cryo-Superficial (P ≤ .001). Use of IA-TA-ER was also associated with the greatest functional score, improvement from baseline, and highest prevalence of patients achieving MCID than other treatments (P ≤ .003). CONCLUSIONS: The IA-TA-ER appears to outperform other treatments in terms of pain relief and functional improvement for up to 4 months following treatment. In addition, outcomes in the novel cryoneurolysis and conventional IA-CS were similar to one another and better than those in IA-HA and IA-NSAIDs.

Periprosthetic Joint Infection Risk After Primary Total Knee Arthroplasty: Are All Preoperative Corticosteroid Injections the Same?

BACKGROUND: Previous evidence has demonstrated an increased risk of periprosthetic joint infection (PJI) following primary total knee arthroplasty (TKA) in patients receiving corticosteroid injection (CSI) within 3 months of surgery. The study aimed to determine if PJI risk after TKA varied among different corticosteroid agents. METHODS: A total of 85,073 patients undergoing primary TKA from 2009 to 2019 were identified from a large national database. Of these, 1,092 (1.3%) received an ipsilateral, intra-articular CSI within 90 days of TKA. These patients were compared to those not receiving CSI using multivariate logistic regressions following 1:4 propensity score matching, with PJI development as the primary outcome. RESULTS: Patients given an injection of any corticosteroid within 90 days of TKA had significantly higher PJI rates compared to controls (1.6 versus 0.41%; P < .001). This finding was driven by patients receiving methylprednisolone acetate (n = 543) or betamethasone (n = 153), with prevalence rates of 1.7 and 2.6%, respectively (P = .003 and P = .01, respectively). No significant increase in the rate of PJI was observed for patients receiving triamcinolone (1.2%; P = .08; n = 342) or dexamethasone (0.0%; P = 1; n = 54) within 90 days preceding TKA. PJI risk for all agents, administered more than 90 days preoperatively normalized to control levels (0.51 versus 0.34%). CONCLUSIONS: These results suggest that PJI risk varies with CSI type. In this large database study, only patients given methylprednisolone acetate or betamethasone injections within 90 days of surgery had significantly higher PJI rates compared to controls.