Acute ampakines increase voiding function and coordination in a rat model of SCI.

Neurogenic bladder dysfunction causes urological complications and reduces the quality of life in persons with spinal cord injury (SCI). Glutamatergic signaling via AMPA receptors is fundamentally important to the neural circuits controlling bladder voiding. Ampakines are positive allosteric modulators of AMPA receptors that can enhance the function of glutamatergic neural circuits after SCI. We hypothesized that ampakines can acutely stimulate bladder voiding that has been impaired due to thoracic contusion SCI. Adult female Sprague-Dawley rats received a unilateral contusion of the T9 spinal cord (n = 10). Bladder function (cystometry) and coordination with the external urethral sphincter (EUS) were assessed 5 d post-SCI under urethane anesthesia. Data were compared to responses in spinal-intact rats (n = 8). The 'low-impact' ampakine CX1739 (5, 10, or 15 mg/kg) or vehicle (2-hydroxypropyl-beta-cyclodextrin [HPCD]) was administered intravenously. The HPCD vehicle had no discernible impact on voiding. In contrast, following CX1739, the pressure threshold for inducing bladder contraction, voided volume, and the interval between bladder contractions were significantly reduced. These responses occurred in a dose-dependent manner. We conclude that modulating AMPA receptor function using ampakines can rapidly improve bladder-voiding capability at subacute time points following contusion SCI. These results may provide a new and translatable method for therapeutic targeting of bladder dysfunction acutely after SCI.

Physical examination and CT to assess thoracic injury in 137 cats presented to UK referral hospitals after trauma.

OBJECTIVES: The aim of the study was to describe clinical examination and thoracic CT (TCT) findings in cats after trauma, and to identify physical examination findings associated with both abnormalities on TCT and the need for therapeutic interventions. METHODS: A multicentre, retrospective, observational study was conducted. Cats admitted to the participating hospitals with a history of blunt trauma and that underwent TCT were eligible. Data were collected on signalment, history, physical examination, TCT findings and subsequent interventions. RESULTS: In total, 137 cats were included. Road traffic accidents (RTAs) were the most frequently reported cause of trauma (69%). Tachypnoea (32%), pale mucous membranes (22%) and dyspnoea (20%) were the most common abnormal findings on thoracic examination. The most frequently identified thoracic pathologies on TCT were atelectasis (34%), pulmonary contusions (33%), pneumothorax (29%) and pleural effusion (20%). Thoracocentesis was the most commonly performed intervention (12%), followed by chest drain placement (7%). A total of 45 (33%) cats had no physical examination abnormalities but did have abnormalities detected on TCT; six of these cats required interventions. Increasing numbers of thoracic abnormalities on clinical examination were associated with increasing likelihood of having abnormal findings on TCT (odds ratio [OR] 2.04, 95% confidence interval [CI] 1.21-3.44, P = 0.008) and of requiring an intervention (OR 1.82, 95% CI 1.32-2.51, P <0.001). CONCLUSIONS AND RELEVANCE: RTAs were the most common reported cause of blunt trauma. Atelectasis, pulmonary contusions and pneumothorax were the most common abnormalities identified on TCT, and thoracic drainage was the most utilised intervention. TCT may be useful in identifying cats with normal thoracic physical examination findings that have significant thoracic pathology, and a high number of abnormal findings on thoracic examination should raise suspicion for both minor and major thoracic pathology. The results of this study can be used to assist in selecting appropriate cases for TCT after blunt trauma.

Epithelial myoepithelial carcinoma of the parotid gland with high-grade transformation.

A woman presented with a painless swelling in front of her right auricle, which, on examination, seemed to be a hard, immobile mass arising from the right parotid gland. CT scan showed a heterogeneously enhancing mass lesion in the superficial lobe of the parotid gland with partial extension into the deep lobe. Fine needle aspiration cytology suggested a high-grade transformation (HGT) with the presence of bizarre tumour cells. She underwent a right-sided total parotidectomy with transient facial neuropraxia in the postoperative period. The final pathological diagnosis of the specimen came out to be epithelial myoepithelial carcinoma with HGT, which is a relatively rare entity, with no defined guidelines for management. Our patient was managed by surgical resection alone without any postoperative radiation therapy, and short-term follow-up results seem to suggest no recurrence.

Timing matters: Early versus late rib fixation in patients with multiple rib fractures and pulmonary contusion.

BACKGROUND: Recent literature has shown that surgical stabilization of rib fractures benefits patients with rib fractures accompanied by pulmonary contusion; however, the impact of timing on surgical stabilization of rib fractures in this patient population remains unexplored. We aimed to compare early versus late surgical stabilization of rib fractures in patients with traumatic rib fractures and concurrent pulmonary contusion. METHODS: We selected all adult patients with isolated blunt chest trauma, multiple rib fractures, and pulmonary contusion undergoing early (<72 hours) versus late surgical stabilization of rib fractures (≥72 hours) using the American College of Surgeons Trauma Quality Improvement Program 2016 to 2020. Propensity score matching was performed to adjust for patient, injury, and hospital characteristics. Our outcomes were hospital length of stay, acute respiratory distress syndrome, unplanned intubation, ventilator days, unplanned intensive care unit admission, intensive care unit length of stay, tracheostomy rates, and mortality. We then performed sub-group analyses for patients with major or minor pulmonary contusion. RESULTS: We included 2,839 patients, of whom 1,520 (53.5%) underwent early surgical stabilization of rib fractures. After propensity score matching, 1,096 well-balanced pairs were formed. Early surgical stabilization of rib fractures was associated with a decrease in hospital length of stay (9 vs 13 days; P < .001), decreased intensive care unit length of stay (5 vs 7 days; P < .001), and lower rates of unplanned intubation (7.4% vs 11.4%; P = .001), unplanned intensive care unit admission (4.2% vs 105%, P < .001), and tracheostomy (8.4% vs 12.4%; P = .002). Similar results were also found in the subgroup analyses for patients with major or minor pulmonary contusion. CONCLUSION: These findings suggest that in patients with multiple rib fractures and pulmonary contusion, the early implementation of surgical stabilization of rib fractures could be beneficial regardless of the severity of pulmonary contusion.

Epidemiology of Lateral Patellar Dislocation Including Bone Bruise Incidence: Five Years of Data from a Trauma Center.

OBJECTIVE: Systematic summary of the epidemiology of patellar dislocation is rare. This study aims to investigate sex-, age-, type-, injury causing events-, incidence of bone bruise and time from last injury (TFLI)-specific characteristics, and detail the epidemiological characteristics of patellar dislocation. METHOD: In this descriptive epidemiological study, a total of 743 patients who have a history of lateral patellar dislocation with either first-time patellar dislocation (FPD) or recurrent patellar dislocation (RPD) between August 2017 and June 2022 at our institution met the inclusion criteria and were selected in this study. Patient characteristics including the type, gender, age, events leading to patellar dislocation, incidence of patellar bone bruise, and the time from last injury (TFLI) of patellar dislocation were retrospectively obtained and described. Magnetic resonance imaging scans (MRI) of the knee were reviewed for insuring bone bruise. RESULTS: Among the 743 patients with patellar dislocation who required surgical reconstruction of the medial retinaculum, 418 (56.2%) had RPD and 325 (43.8%) had FPD. There were more females (65.0%) than males (35.0%) in patellar dislocation patients. Among the female patients, those aged <18 years had higher incidence (31.4%) of patellar dislocation. Among the male patients, those aged <18 and 19-28 years had higher incidence (16.8%) of patellar dislocation. Of all age groups, the prevalence rate of patellar dislocation was high in juvenile population and females, but with no statistical significance. The most common patellar dislocation-causing event was sport accidents (40.1%), followed by life accidents (23.2%). The incidence of left-knee patellar dislocation was slightly higher than that of right-knee patellar dislocation. The incidence of patellar bone bruise of RPD (63.2%) was significantly lower (p < 0.05) than that of FPD (82.2%). Patellar dislocation patients with bone bruise had shorter time from last injury (TFLI) than those without patellar bone bruise (p < 0.05). CONCLUSIONS: The incidence of bone bruise of RPD was lower than that of FPD, and patients with patellar bone bruise may have a shorter time from last injury than those without bone bruise.

[Complications after conservative vs. operative treatment of severe thoracic trauma]. / Komplikationen nach operativer vs. konservativer Versorgung des schweren Thoraxtraumas.

BACKGROUND: Thoracic trauma is a frequent injury in the routine treatment of injured patients. Due to the increasing demographic changes a further increase is to be expected, especially after low-energy trauma. OBJECTIVE: Expected complications after conservative vs. operative treatment of various injury patterns of thoracic trauma. MATERIAL AND METHODS: Evaluation of a selective literature search regarding possible complications after thoracic trauma and formulation of instructions for action as expert recommendations. CONCLUSION: Both conservative and operative treatment of thoracic trauma have their specific complications, which have to be known to the treating physician. Lung contusions are often underestimated in the initial radiological diagnostics but often lead to relevant problems during the further course of treatment. After conservative treatment of rib fractures persistent pain, functional limitations or even relevant deformities due to secondary dislocation, can remain. There is a significant risk of overlooking or underestimating relevant injuries during the initial diagnostics which then leads to secondary complications. By far the most frequent risk of surgical treatment is an incorrect positioning of chest tubes. Overall, postoperative infections after chest trauma are relatively rare.

Fulminant sepsis secondary to severe lung contusion from the Lund University Cardiopulmonary Assist System device.

INTRODUCTION: Portable mechanical chest compression devices have been developed to improve upon many problems of manual compression, increase patient survival, and improve neurologic outcomes. However, the use of these devices is not without risk of harm to the patient. CASE REPORT: We describe a patient who received chest compressions from a mechanical compression device after cardiac arrest and subsequently developed fulminant sepsis secondary to lung contusions and a necrotizing pulmonary infection. DISCUSSION: Although injuries from the LUCAS have been reported, we believe this is the first reported fatal complication related to direct pulmonary injury from a mechanical compression device. CONCLUSION: More investigation is needed to determine the safety and efficacy of the LUCAS especially in obese patients.

Variations in the Neurosurgical Management of Depressed Skull Fractures in Adults: An International Cross-Sectional Survey.

BACKGROUND: Depressed skull fractures have been well described since antiquity, yet its management remains controversial. Contentious issues include the use of prophylactic antibiotics and antiepileptics, the role of nonoperative management, and the replacement/removal of bone fragments. Our objective was to explore the management patterns of closed and open depressed skull fractures across the world. METHODS: A 23-item, web-based survey was distributed electronically to the members of national neurosurgical associations, and on social media platforms. The survey was open for data collection from December 2020 to April 2021. RESULTS: A total of 218 respondents completed the survey, representing 56 countries.With regard to open fractures, most respondents (85.8%) treated less than 50 cases annually. Most respondents (79.4%) offered prophylactic antibiotics to all patients with open fractures, with significant geographical variation (p < 0.001). Less than half of the respondents (48.2%) offered prophylactic antiepileptics. Almost all respondents (>90%) reported the following indications as important for surgical management: (1) grossly contaminated wound, (2) dural penetration, (3) depth of depression, and (4) underlying contusion/hematoma with mass effect. Most respondents treated less than 50 cases of closed depressed skull fractures annually. Most European respondents (81.7%) did not offer prophylactic antiepileptics in comparison to most Asian respondents (52.7%; p < 0.001). Depth of depression, an underlying hematoma/contusion with mass effect, and dural penetration were the most important surgical indications. CONCLUSIONS: There remains a great degree of uncertainty in the management strategies employed across the world in treating depressed fractures, and future work should involve multinational randomized trials.

Clinical presentation of childhood soft tissue sarcomas: a systematic review and meta-analysis.

BACKGROUND: Time to diagnosis (TTD) of childhood soft tissue sarcoma (STS) is significantly associated with survival. This review aims to identify pre-diagnostic symptoms/signs to inform earlier diagnosis interventions. METHODS: Medline, Embase, Cochrane and Web-of-Science were searched between January 2010 and February 2021 for studies including children (<18 years) diagnosed with STS, with no language restrictions. Pooled proportions of symptoms/signs were calculated and subanalysed by tumour location and age. RESULTS: Fifty-nine eligible studies were identified, totalling 2462 cases. The most frequent symptoms were lump/swelling (38%, 95% CI 27% to 51%), pain (6%, 95% CI 3% to 10%), cutaneous changes (4%, 95% CI 0 to 9%), localised eye swelling (3%, 95% CI 0 to 7%), cranial nerve deficits (2%, 95% CI 0 to 5%) and constitutional symptoms (2%, 95% CI 0 to 5%).Symptoms varied by location and age. Localised eye swelling (20%, 95% CI 3% to 45%), cranial nerve deficits (14%, 95% CI 4% to 28%) and impaired visual function (6%, 95% CI 0 to 17%) were frequent in head and neck tumours. For abdomen/pelvic tumours, urinary symptoms (24%, 95% CI 5% to 15%), abdominal distension/discomfort (22%, 95% CI 4% to 47%), genital lump/swelling (16%, 95% CI 1% to 42%), constitutional symptoms (9%, 95% CI 0%] to 23%), vaginal bleeding (7%, 95%C I 0 to 21%) and bowel habit changes (6%, 95% CI 0 to 17%) were frequent.In <5 years, consumptive coagulopathy (16%, 95% CI 0 to 48%), cutaneous changes (5%, 95% CI 0 to 40%), genital lump/swelling (4%, 95% CI 0 to 14%), reduced mobility (3%, 95% CI 0 to 11%), vaginal bleeding (2%, 95% CI 0 to 11%) and bleeding/bruising/petechiae (2%, 95% CI 0 to 20%) were frequent compared with lump/swelling, constitutional symptoms, pain and headaches which were frequent among >11 years. CONCLUSIONS: For STS, pre-diagnostic symptoms differ by age and location, highlighting the need to tailor early diagnosis interventions.

High positive end-expiratory pressure ventilation mitigates the progression from unilateral pulmonary contusion to ARDS: An animal study.

BACKGROUND: Pulmonary contusion (PC) is common in severely traumatized patients and can lead to respiratory failure requiring mechanical ventilation (MV). Ventilator-induced lung injury (VILI) might aggravate lung damage. Despite underrepresentation of trauma patients in trials on lung-protective MV, results are extrapolated to these patients, potentially disregarding important pathophysiological differences. METHODS: Three MV protocols with different positive end-expiratory pressure (PEEP) levels: ARDSnetwork lower PEEP (ARDSnet-low), ARDSnetwork higher PEEP (ARDSnet-high), and open lung concept (OLC) were applied in swine for 24 hours following PC. Gas exchange, lung mechanics, quantitative computed tomography, and diffuse alveolar damage (DAD) score were analyzed. Results are given as median (interquartile range) at 24 hours. Statistical testing was performed using general linear models (group effect) over all measurement points and pairwise Mann-Whitney U tests for DAD. RESULTS: There were significant differences between groups: PEEP ( p < 0.0001) ARDSnet-low (8 [8-10] cmH 2 O), ARDSnet-high (12 [12-12] cmH 2 O), OLC (21 [20-22] cmH 2 O). The fraction of arterial partial pressure of oxygen and inspired oxygen fraction ( p = 0.0016) was lowest in ARDSnet-low (78 (73-111) mm Hg) compared with ARDSnet-high (375 (365-423) mm Hg) and OLC (499 (430-523) mm Hg). The end-expiratory lung volume (EELV) differed significantly ( p < 0.0001), with highest values in OLC (64% [60-70%]) and lowest in ARDSnet-low (34% [24-37%]). Costa's surrogate for mechanical power differed significantly ( p < 0.0001), with lowest values for ARDSnet-high (73 [58-76]) compared with OLC (105 [108-116]). Diffuse alveolar damage was lower in ARDSnet-high compared with ARDSnet-low (0.0007). CONCLUSION: Progression to ARDS, 24 hours after PC, was mitigated by OLC and ARDSnet-high. Both concepts restored EELV. ARDSnet-high had the lowest mechanical power surrogate and DAD. Our data suggest, that ARDSnet-high restored oxygenation and functional lung volume and reduced physiological and histological surrogates for VILI. ARDSnet-low generated unfavorable outcomes, such as loss of EELV, increased mechanical power and DAD after PC in swine. The high respiratory rate in the OLC may blunt favorable effects of lung recruitment.

Characterization of Vasogenic and Cytotoxic Brain Edema Formation After Experimental Traumatic Brain Injury by Free Water Diffusion Magnetic Resonance Imaging.

Brain edema formation is a key factor for secondary tissue damage after traumatic brain injury (TBI), however, the type of brain edema and the temporal profile of edema formation are still unclear. We performed free water imaging, a bi-tensor model based diffusion MRI analysis, to characterize vasogenic brain edema (VBE) and cytotoxic edema (CBE) formation up to 7 days after experimental TBI. Male C57/Bl6 mice were subjected to controlled cortical impact (CCI) or sham surgery and investigated by MRI 4h, 1, 2, 3, 5, and 7 days thereafter (n = 8/group). We determined mean diffusivity (MD) and free water (FW) in contusion, pericontusional area, ipsi- and contralateral brain tissue. Free (i.e., non-restricted) water was interpreted as VBE, restricted water as CBE. To verify the results, VBE formation was investigated by in-vivo 2-Photon Microscopy (2-PM) 48h after surgery. We found that MD and FW values decreased for 48h within the contusion, indicating the occurrence of CBE. In pericontusional tissue, MD and FW indices were increased at all time points, suggesting the formation of VBE. This was consistent with our results obtained by 2-PM. Taken together, CBE formation occurs for 48h after trauma and is restricted to the contusion, while VBE forms in pericontusional tissue up to 7 days after TBI. Our results indicate that free water magnetic resonance imaging may represent a promising tool to investigate vasogenic and cytotoxic brain edema in the laboratory and in patients.

Evolution of Pulmonary Contusions in Patients With Severe Rib Fractures: Cause for Concern?

INTRODUCTION: The progression of pulmonary contusions remains poorly understood. This study aimed to measure the radiographic change in pulmonary contusions over time and evaluate the association of the radiographic change with clinical outcomes and surgical stabilization of rib fractures (SSRF). METHODS: This retrospective cohort study included adults admitted with three or more displaced rib fractures or flail segment on trauma CT and when a chest CT was repeated within one week after trauma. Radiographic severity of pulmonary contusions was assessed using the Blunt Pulmonary Contusion Score (BPC18). Logistic regression was performed to evaluate the relation between SSRF and worsening contusions on repeat CT, adjusted for potential confounders. RESULTS: Of 231 patients, 56 (24%) had a repeat CT scan. Of these, 55 (98%) had pulmonary contusion on the first CT scan with a median BPC18 score of 5 (P25-P75 3-7). Repeat CTs showed an overall decrease of the median BPC18 score to 4 (P25-P75 2-6, P = .02), but demonstrated a worsening of the pulmonary contusion in 16 patients (29%). All repeat CTs conducted within 12 hours post-injury demonstrated increasing BPC18. Radiographic worsening of pulmonary contusions was not associated with SSRF, nor with worse respiratory outcomes or intensive care length of stay, compared to patients with radiographically stable or improving contusions. DISCUSSION: In patients with severe rib fracture patterns who undergo repeat imaging, pulmonary contusions are prevalent and become radiographically worse within at least the first 12 hours after injury. No association between radiographic worsening and clinical outcomes was found.

Early risk factors for prolonged mechanical ventilation in patients with severe blunt thoracic trauma: A retrospective cohort study.

BACKGROUND: A significant proportion of patients with severe chest trauma require mechanical ventilation (MV). Early prediction of the duration of MV may influence clinical decisions. We aimed to determine early risk factors for prolonged MV among adults suffering from severe blunt thoracic trauma. METHODS: This retrospective, single-center, cohort study included all patients admitted between January 2014 and December 2020 due to severe blunt chest trauma. The primary outcome was prolonged MV, defined as invasive MV lasting more than 14 days. Multivariable logistic regression was performed to identify independent risk factors for prolonged MV. RESULTS: The final analysis included 378 patients. The median duration of MV was 9.7 (IQR 3.0-18.0) days. 221 (58.5 %) patients required MV for more than 7 days and 143 (37.8 %) for more than 14 days. Male gender (aOR 3.01, 95 % CI 1.63-5.58, p < 0.001), age (aOR 1.40, 95 % CI 1.21-1.63, p < 0.001, for each category above 30 years), presence of severe head trauma (aOR 3.77, 95 % CI 2.23-6.38, p < 0.001), and transfusion of >5 blood units on admission (aOR 2.85, 95 % CI 1.62-5.02, p < 0.001) were independently associated with prolonged MV. The number of fractured ribs and the extent of lung contusions were associated with MV for more than 7 days, but not for 14 days. In the subgroup of 134 patients without concomitant head trauma, age (aOR 1.63, 95 % CI 1.18-2.27, p = 0.004, for each category above 30 years), respiratory comorbidities (aOR 9.70, 95 % CI 1.49-63.01, p = 0.017), worse p/f ratio during the first 24 h (aOR 1.55, 95 % CI 1.15-2.09, p = 0.004), and transfusion of >5 blood units on admission (aOR 5.71 95 % CI 1.84-17.68, p = 0.003) were independently associated with MV for more than 14 days. CONCLUSIONS: Several predictors have been identified as independently associated with prolonged MV. Patients who meet these criteria are at high risk for prolonged MV and should be considered for interventions that could potentially shorten MV duration and reduce associated complications. Hemodynamically stable, healthy young patients suffering from severe thoracic trauma but no head injury, including those with extensive lung contusions and rib fractures, have a low risk of prolonged MV.

Posttraumatic pneumonia exacerbates bone marrow erythropoietic dysfunction.

INTRODUCTION: Pneumonia is a common complication after severe trauma that is associated with worse outcomes with increased mortality. Critically ill trauma patients also have persistent inflammation and bone marrow dysfunction that manifests as persistent anemia. Terminal erythropoiesis, which occurs in bone marrow structures called erythroblastic islands (EBIs), has been shown to be impacted by trauma. Using a preclinical model of polytrauma (PT) and pneumonia, we sought to determine the effect of infection on bone marrow dysfunction and terminal erythropoiesis. METHODS: Male and female Sprague-Dawley rats aged 9 to 11 weeks were subjected to either PT (lung contusion, hemorrhagic shock, cecectomy, and bifemoral pseudofracture) or PT with postinjury day 1 Pseudomonas pneumonia (PT-PNA) and compared with a naive cohort. Erythroblastic islands were isolated from bone marrow samples and imaged via confocal microscopy. Hemoglobin, early bone marrow erythroid progenitors, erythroid cells/EBI, and % reticulocytes/EBI were measured on day 7. Significance was defined as p < 0.05. RESULTS: Day 7 hemoglobin was significantly lower in both PT and PT-PNA groups compared with naive (10.8 ± 0.6 and 10.9 ± 0.7 vs. 12.1 ± 0.7 g/dL [ p < 0.05]). Growth of bone marrow early erythroid progenitors (colony-forming units-granulocyte, erythrocyte, monocyte, megakaryocyte; erythroid burst-forming unit; and erythroid colony-forming unit) on day 7 was significantly reduced in PT-PNA compared with both PT and naive. Despite a peripheral reticulocytosis following PT and PT-PNA, the percentage of reticulocytes/EBI was not different between naive, PT, and PT-PNA. However, the number of erythroblasts/EBI was significantly lower in PT-PNA compared with naive (2.9 ± 1.5 [ p < 0.05] vs. 8.9 ± 1.1 cells/EBI macrophage). In addition to changes in EBI composition, EBIs were also found to have significant structural changes following PT and PT-PNA. CONCLUSION: Multicompartmental PT altered late-stage erythropoiesis, and these changes were augmented with the addition of pneumonia. To improve outcomes following trauma and pneumonia, we need to better understand how alterations in EBI structure and function impact persistent bone marrow dysfunction and anemia.

Lateral femoral chondral lesions are more frequent when an anterior cruciate ligament tear is concomitant with a lateral femoral notch sign, but do not progress over time.

BACKGROUND: The lateral femoral notch sign (LFNS) is caused by an impact to the lateral femoral condyle during a pivot shift injury and affects 25% to 33% of patients with an anterior cruciate ligament (ACL) rupture. The primary aim of this study was to compare the incidence of chondral lesions 1year after ACL reconstruction, while taking into consideration preoperative chondral damage, in patients with and without a preoperative LFNS. The primary outcome measure was the presence of chondral lesions involving the lateral femoral condyle, confirmed on magnetic resonance imaging (MRI) using the Outerbridge classification, at 1year postoperative. The secondary outcome measures were bone bruise of the lateral femoral condyle confirmed on MRI, the International Knee Documentation Committee (IKDC), Lysholm and Tegner functional scores taken 1year after surgery. METHODS: Sixty patients were included-30 with preoperative LFNS and 30 without-in a retrospective, comparative study of prospectively collected data on patients operated between August 2018 and December 2020. RESULTS: A lateral femoral chondral lesion 1year after surgery was significantly more common in the group with a preoperative LFNS (37% [n=11] versus 13% [n=4] in the group without a preoperative LFNS, p=0.036). Adjusting the statistical analysis for preoperative body mass index (BMI) did not impact these results (adjusted odds ratio [OR]=3.83 [95%CI: 1.03-14.24]; p=0.045). Adjusting for a preoperative lateral femoral chondral lesion had an impact on these results (adjusted OR=0.78 [95%CI: 0.12-5.08]; p=0.793). This indicates that a preoperative LFNS is not significantly and independently associated with a lateral femoral chondral lesion at 1year postoperative when the analysis is adjusted for a preoperative lateral femoral chondral lesion. However, having a preoperative lateral femoral chondral lesion is significantly correlated with the presence of a lateral femoral chondral lesion 1year after the surgery (adjusted OR=63.31 [95%CI: 5.94-674.8]; p=0.001). There were no significant differences in terms of bone bruise on MRI (p=1.0), or for the IKDC (p=0.310), Lysholm (p=0.416) and Tegner (p=0.644) functional scores. The LFNS was still present in 21 out of 30 patients (70%) at 1year postoperative. The preoperative LFNS was significantly smaller in the group without a chondral lesion compared to the group with a chondral lesion 1year after the surgery (median=2.30mm [IQR: 1.40; 3.00] versus 3.10mm [IQR: 2.50; 3.40]; p value=0.045). CONCLUSIONS: Patients with a preoperative LFNS are three times more likely to have a chondral lesion in the notch region 1year after surgery. These chondral lesions are concomitant to the injury and do not progress over time. LEVEL OF EVIDENCE: III.

Spinal decompression surgery may alleviate vasopressor-induced spinal hemorrhage and extravasation during acute cervical spinal cord injury in rats.

BACKGROUND: Cervical spinal injury often disrupts the supraspinal vasomotor pathways projecting to the thoracic sympathetic preganglionic neurons, leading to cardiovascular dysfunction. The current guideline is to maintain the mean arterial blood pressure at 85 to 90 mmHg using a vasopressor during the first week of the injury. Some studies have demonstrated that this treatment might be beneficial to alleviate secondary injury and improve neurological outcomes; however, elevation of blood pressure may exacerbate spinal hemorrhage, extravasation, and edema, exacerbating the initial injury. PURPOSE: The present study was designed to (1) examine whether vasopressor administration exacerbates spinal hemorrhage and extravasation; (2) evaluate whether spinal decompression surgery relieves vasopressor-induced spinal hemorrhage and extravasation. STUDY DESIGN: In vivo animal study. METHODS: Animals received a saline solution or a vasopressor (phenylephrine hydrochloride, 500 or 1000 µg/kg, 7 mL/kg/h) after mid-cervical contusion with or without spinal decompression (ie, incision of the dura and arachnoid mater). Spinal cord hemorrhage and extravasation were examined by expression of Evans blue within the spinal cord section. RESULTS: The results demonstrated that cervical spinal contusion significantly reduced the mean arterial blood pressure and induced spinal hemorrhage and extravasation. Phenylephrine infusion significantly elevated the mean arterial blood pressure to the preinjury level within 15 to 60 minutes postcontusion; however, spinal hemorrhage and extravasation were more extensive in animals that received phenylephrine than in those that received saline. Notably, spinal decompression mitigated spinal hemorrhage and extravasation in contused rats who received phenylephrine. CONCLUSIONS: These data indicate that, although phenylephrine can prevent hypotension after cervical spinal injury, it also causes excess spinal hemorrhage and extravasation. CLINICAL SIGNIFICANCE: Spinal decompressive surgery seemed to minimize the side effect of phenylephrine as vasopressor treatment during acute spinal cord injury.

Sustained pain and macrophage infiltration in a mouse muscle contusion model.

INTRODUCTION/AIMS: Prior studies have emphasized the role of inflammation in the response to injury and muscle regeneration, but little emphasis has been placed on characterizing the relationship between innate inflammation, pain, and functional impairment. The aim of our study was to determine the contribution of innate immunity to prolonged pain following muscle contusion. METHODS: We developed a closed-impact mouse model of muscle contusion and a macrophage-targeted near-infrared fluorescent nanoemulsion. Closed-impact contusions were delivered to the lower left limb. Pain sensitivity, gait dysfunction, and inflammation were assessed in the days and weeks post-contusion. Macrophage accumulation was imaged in vivo by injecting i.v. near-infrared nanoemulsion. RESULTS: Despite hindpaw hypersensitivity persisting for several weeks, disruptions to gait and grip strength typically resolved within 10 days of injury. Using non-invasive imaging and immunohistochemistry, we show that macrophage density peaks in and around the affected muscle 3 day post-injury and quickly subsides. However, macrophage density in the ipsilateral sciatic nerve and dorsal root ganglia (DRG) increases more gradually and persists for at least 14 days. DISCUSSION: In this study, we demonstrate pain sensitivity is influenced by the degree of lower muscle contusion, without significant changes to gait and grip strength. This may be due to modulation of pain signaling by macrophage proliferation in the sciatic nerve, upstream from the site of injury. Our work suggests chronic pain developing from muscle contusion is driven by macrophage-derived neuroinflammation in the peripheral nervous system.

Pulsed Red and Blue Photobiomodulation for the Treatment of Thigh Contusions and Soft Tissue Injury: A Randomized Controlled Trial.

CONTEXT: Contusion and soft tissue injuries are common in sports. Photobiomodultion, light and laser therapy, is an effective aid to increase healing rates and improve function after various injury mechanisms. However, it is unclear how well photobiomodulation improves function after a contusion soft tissue injury. This study aimed to determine the effects of a pulsed red and blue photobiomodulation light patch on muscle function following a human thigh contusion injury. DESIGN: Single-blinded randomized control trial design. METHODS: We enrolled 46 healthy participants. Participants completed 5 visits on consecutive days. On the first visit, participants completed a baseline isokinetic quadriceps strength testing protocol at 60°/s and 180°/s. On the second visit, participants were struck in the rectus femoris of the anterior thigh with a tennis ball from a serving machine. Immediately following, participants were treated for 30 minutes with an active or placebo photobiomodulation patch (CareWear light patch system, CareWear Corp). Following the treatment, participants completed the same isokinetic quadriceps strength testing protocol. Participants completed the treatment and isokinetic quadriceps strength test during the following daily visits. We normalized the data by calculating the percent change from baseline. We used a mixed model analysis of covariance, with sex as a covariate, to determine the difference between treatment groups throughout the acute recovery process. RESULTS: We found the active photobiomodulation treatment significantly increased over the placebo group, quadriceps peak torque during the 180°/s test (P = .030), and average power during both the 60°/s (P = .041) and 180°/s (P ≤ .001) assessments. The mean peak torque and average power of 180°/s, at day 4, exceeded the baseline levels by 8.9% and 16.8%, respectively. CONCLUSIONS: The red and blue photobiomodulation light patch improved muscle strength and power during the acute healing phase of a human thigh contusion injury model.