Estimates of Golf-Related Upper Extremity Injuries in the United States: A 10-Year Epidemiology Study (2011-2020).

BACKGROUND: Golf is one of the most popular sports in the United States (US) and is played by participants of all ages and skill level. Given the popularity and sport-specific demands on the upper torso, golf poses a considerable risk for upper extremity (UE) injuries. Therefore, the aim of the current study was to (1) determine the incidence rate of UE golf injuries presenting to emergency departments (EDs) in the US, (2) determine the most commonly injured body parts and mechanisms of injury, and (3) compare current injury epidemiology with previous trends in the literature. HYPOTHESIS: Male sex, bimodal age extremes (young and elderly), and utilization of golf carts (vs walking) are associated with a higher incidence of golf-related UE injuries. STUDY DESIGN: Descriptive epidemiology study. LEVEL OF EVIDENCE: Level 3. METHODS: The National Electronic Injury Surveillance System (NEISS) is a statistically validated injury surveillance system that collects data from ED visits as a representative probability sample of hospitals in the US. We queried the NEISS for the years 2011 to 2020 to examine the following variables for golf-related UE injuries: sociodemographic, diagnosis, body part, and mechanism of injury. RESULTS: From 2011 to 2020, there were a total of 1862 golf-related UE injuries presenting to participating EDs, which correlates to an estimated 70,868 total injuries. Overall, male golf players were disproportionately affected (69.2%) versus female golf players (30.8%) and the most commonly injured age groups were those aged >60 and 10 to 19 years. The most common injuries included fractures (26.8%), strains/sprains (23.4%), and soft tissue injuries (15.9%). The joints injured most frequently were the shoulder (24.8%), wrist (15.6%), and joints in the hand (12.0%). The most common mechanisms of injury were cart accidents (44.63%), falling/tripping (29.22%), and golf club swinging/mechanics (10.37%). CONCLUSION: Golf-related UE injuries can be acute or due to chronic overuse. Male athletes >60 years of age were the population most commonly presenting to the ED with a golf-related injury. Further, the shoulder, forearm, and wrist were most commonly injured. These findings are consistent with previous epidemiological trends in the literature. Interventions to reduce the incidence of injury should be sport-specific and focus primarily on equipment and golf cart safety and swing modification to optimize the biomechanical function of the UEs. CLINICAL RELEVANCE: Our findings indicate that golf-related injury prevention programs should target UE injuries, particularly among young (<19) and older (>60 years) golfers with poor swing mechanics.

Arthroscopic Distal Clavicle Bone Block Technique for Anteroinferior Instability With Critical Bone Loss.

Arthroscopic distal clavicle autograft represents a locally available source of autograft for bone block augmentation in patients with anterior shoulder instability with glenoid bone loss. Anatomic and biomechanical studies have supported distal clavicle autograft use as comparable to coracoid graft with regard to restoration of glenoid articular surface, with the theoretical advantage of minimizing complications associated with coracoid transfer procedures, such as neurologic injury and coracoid fracture. The current technique describes a modification of those previously described, including a mini-open approach for distal clavicle autograft harvest, orientation of the distal clavicle with the medial clavicle graft against the glenoid (congruent arc), an all-arthroscopic technique of graft passage, and graft placement and fixation using specialized drill guides and four suture buttons to reproducibly place and secure the graft with final capsulolabral advancement over the graft to render it extra-articular.

Direct versus indirect posterior malleolar fixation in the treatment of trimalleolar ankle fractures: Is there a difference in outcomes?

Purpose: The purpose of this study was to examine the differences in functional outcomes between direct and indirect surgical fixation methods of the posterior malleolus in the setting of trimalleolar fractures and identify any variables affecting patient outcomes. Methods: Primary outcomes were evaluated by PROMIS scores for short-term outcomes regarding total pain (TP) and total function (TF) comparing 40 patients with direct fixation with 77 with indirect fixation. Continuous variables were analyzed using t tests for parametric variables and the Mann-Whitney U test for nonparametric variables. Categorical variables were analyzed using a χ2 test. Univariate and multivariate linear regression models were performed to analyze factors that affect outcomes of TP and TF. Results: There was no difference in TP or TF between groups (P = 0.65 vs. P = 0.19). On univariate linear regression for TP, BMI, incidence of complication, tobacco use, and open injury showed significance in increasing pain levels with open injuries providing the greatest effect (coef = 11.8). On multivariate analysis, BMI, incidence of complication, open injury, and tourniquet time all significantly increased pain. For TF, univariate analysis showed age, BMI, incidence of complication, and diabetes to decrease function, and use of external fixator and tourniquet time increased function. In the multivariate model, increased BMI, open injuries, and increasing tourniquet time all decreased TF while use of an external fixator increased TF. Conclusion: This study showed no difference in TP and TF using the PROMIS outcome scores when comparing direct fixation versus indirect fixation under univariate and multivariate models. Level of Evidence: Therapeutic III.

Epidemiology of Sports-Related Clavicle Fractures in the United States: Injuries From 2015 to 2019.

Background: Clavicle fractures are common orthopaedic injuries that frequently occur during sports and recreational activity. Purpose: To (1) determine the incidence rate of sports-related clavicle fractures among patients evaluated in emergency departments in the United States over a 5-year period, (2) determine the most common sports and risks associated with clavicle fractures, and (3) update the literature by comparing past and present injury trends. Study Design: Descriptive epidemiology study. Methods: The National Electronic Injury Surveillance System (NEISS) database was queried for patients evaluated with clavicle fractures in US emergency departments from 2015 to 2019. The authors evaluated the data by age, sex, race, and sport/recreational activity. Injuries were characterized based on sports-specific mechanism of injury. Using the NEISS weighted multiplier, the authors estimated annual incidence rates based on US Census data. Contingency table comparisons of categorical variables (ie, age groups vs sex distributions) were analyzed using either chi-square or Fisher exact tests as appropriate for the population size, while continuous variable comparisons were performed using 1-way analysis of variance statistical testing. Results: A total of 2386 athletic-related clavicle fractures were evaluated at participating emergency departments, translating to 304,211 clavicle fractures, with an annual per-year injury rate of 18.72 clavicle fractures per 100,000 persons at risk (95% CI, 15.28-23.67). Male athletes had disproportionately higher injury rates than female athletes (P < .001) for every year of the study and demonstrated a higher incidence of fractures compared with female athletes (injury proportion ratio, 5.54). Patients aged 10 to 19 years accounted for the highest overall incidence of injury (64.5%). The annual incidence rate of athletic-related clavicle fractures was not significantly different during the study period (P = .24). The most common mechanisms of injury were participation in football (26.87%), soccer (15.76%), snowboarding (5.03%), bicycling (3.77%), wrestling (3.65%), and snow skiing (3.52%). Conclusion: Study findings indicated that clavicle fractures sustained during sports and recreational activity disproportionately affect male athletes. Adolescent populations (10-19 years of age) had the highest overall incidence of injury, and the most common activities associated with clavicle fractures were football and soccer.

Serology and Comorbidities in Patients With Fracture Nonunion: A Multicenter Evaluation of 640 Patients.

INTRODUCTION: This multicenter cohort study investigated the association of serology and comorbid conditions with septic and aseptic nonunion. METHODS: From January 1, 2011, to December 31, 2017, consecutive individuals surgically treated for nonunion were identified from seven centers. Nonunion-type, comorbid conditions and serology were assessed. RESULTS: A total of 640 individuals were included. 57% were male with a mean age of 49 years. Nonunion sites included tibia (35.2%), femur (25.6%), humerus (20.3%), and other less frequent bones (18.9%). The type of nonunion included septic (17.7%) and aseptic (82.3%). Within aseptic, nonvascular (86.5%) and vascular (13.5%) nonunion were seen. Rates of smoking, alcohol abuse, and diabetes mellitus were higher in our nonunion cohort compared with population norms. Coronary artery disease and tobacco use were associated with septic nonunion (P < 0.05). Diphosphonates were associated with vascular nonunion (P < 0.05). Serologically, increased erythrocyte sedimentation rate, C-reactive protein, parathyroid hormone, red cell distribution width, mean platelet volume (MPV), and platelets and decreased absolute lymphocyte count, hemoglobin, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and albumin were associated with septic nonunion while lower calcium was associated with nonvascular nonunion (P < 0.05). The presence of four or more of increased erythrocyte sedimentation rate, C-reactive protein, or red cell distribution width; decreased albumin; and age younger than 65 years carried an 89% positive predictive value for infection. Hypovitaminosis D was seen less frequently than reported in the general population, whereas anemia was more common. However, aside from hematologic and inflammatory indices, no other serology was abnormal more than 25% of the time. DISCUSSION: Abnormal serology and comorbid conditions, including smoking, alcohol abuse, and diabetes mellitus, are seen in nonunion; however, serologic abnormalities may be less common than previously thought. Septic nonunion is associated with inflammation, younger age, and malnourishment. Based on the observed frequency of abnormality, routine laboratory work is not recommended for nonunion assessment; however, specific focused serology may help determine the presence of septic nonunion.

Ulnar Resection Length: A Risk Factor for Nonunion in Ulnar Shortening Osteotomy.

BACKGROUND: Nonunion rates following ulnar shortening osteotomy (USO) are reported up to 18% with few known risk factors. While resection length is variable in practice, little is known about the prognostic implications on healing. The purpose of this study was to evaluate whether longer resection lengths increased the odds of nonunion. METHODS: A retrospective review was performed on patients who underwent an elective USO at a single institution over a 6-year period. Demographic, social, comorbidity, and surgical data were reviewed. Ulnar resection length was obtained from operative notes and dichotomized into smaller (<5.5 mm) and larger (≥5.5 mm) groups. The primary outcome was the rate of nonunion. Univariate analyses and a multivariable logistic regression model were used to assess for significant predictors of nonunion. RESULTS: A total of 87 patients were included with a mean age of 45 years. Patient comorbidities included 12.6% with diabetes, 29.9% with an American Society of Anesthesiologists score of ≥ 3, 5.8% reporting current tobacco use, and 29.9% reporting former tobacco use. There were 55 patients (63.2%) with resection lengths < 5.5 mm and 32 patients (36.8%) with ≥ 5.5 mm resections. Multivariable analysis identified longer resection length (≥5.5 mm) and current tobacco use as independent risk factors for nonunion. Patients with a resection length of ≥ 5.5 mm had 20.2 times greater odds of nonunion compared with patients with smaller resections, and current smokers had 72.2 times greater odds of nonunion compared with nonsmokers. CONCLUSION: Longer ulnar resection length (≥5.5 mm) significantly increases the risk of nonunion following USO.

Deltoid ligament repair versus trans-syndesmotic fixation for bimalleolar equivalent ankle fractures.

INTRODUCTION: The role of deltoid ligament repair is controversial in the treatment of bimalleolar equivalent ankle injuries. Our purpose was to compare midterm functional outcomes and reoperation rates of unstable distal fibula fractures treated with open reduction internal fixation (ORIF) of the fibula and either deltoid ligament repair, trans-syndesmotic fixation, or combined fixation. METHODS: Skeletally mature subjects were retrospectively identified after fixation of isolated unstable distal fibula fractures treated at a single academic level 1 hospital from January 2005 to May 2019. The AAOS Foot and Ankle Module outcomes questionnaire (AAOS-FAM) was obtained at a mean time from surgery of 4.6 +/- 3.1 years. Subjects underwent one of three methods of fixation including distal fibula ORIF and one of the following: trans-syndesmotic fixation (N = 66), deltoid ligament repair (N = 16), or combined trans-syndesmotic fixation and deltoid ligament repair (N = 26). Outcomes scores and Charlson Comorbidity Index scores were compared between groups by Kruskal-Wallis testing for non-normally distributed data. Rates of reoperation were compared by Fisher's exact test. Statistical significance was set to P < 0.05 for all comparisons. RESULTS: There was no significant difference in AAOS-FAM scores between the three groups (P = 0.18). No subjects in the deltoid ligament repair group underwent reoperation compared to 17 (26%) in the trans-syndesmotic fixation group and six (23%) in the combined fixation group. The most common reason for reoperation was removal of hardware, which was performed in 12 (18%) subjects in the trans-syndesmotic fixation group and three (12%) subjects in the combined fixation group. CONCLUSIONS: Direct deltoid ligament repair yields similar functional scores and fewer reoperations compared to trans-syndesmotic fixation at midterm follow up. Deltoid ligament repair may be a favorable treatment strategy when considering trans-syndesmotic fixation in the surgical treatment of unstable distal fibula fractures.

Shoulder dislocations among high school-aged and college-aged athletes in the United States: an epidemiologic analysis.

HYPOTHESIS/BACKGROUND: Shoulder dislocations are common orthopedic injuries due to the mobile nature of the glenohumeral joint. High school and collegiate athletes are at particularly high risk for sustaining a dislocation event. Despite the prevalence of these injuries, there is a paucity in the literature regarding incidence of sports-related shoulder dislocations and mechanism of injury within these populations. Therefore, the aim of the present study was to (1) determine the incidence rate of shoulder dislocations in high school-aged and collegiate-aged athletes presenting to emergency departments (EDs) in the United States; (2) to determine the most common sports associated with shoulder dislocations; and (3) to compare the current rates and risk factors for shoulder dislocation with previous trends. METHODS: The National Electronic Injury Surveillance System is a statistically validated injury surveillance system that collects data from ED visits as a representative probability sample of hospitals in the United States. We queried the National Electronic Injury Surveillance System for the years 2015-2019 to examine the following variables for sports-related shoulder dislocations: patient age (high school = 13-17 years of age; collegiate = 18-23 years of age), sex, year of admission, and sport type. Using a weighted multiplier, annual incidence rates were estimated based on the US Census estimates and injury rates were compared by sex and age group across the study period. RESULTS: From 2015 to 2019, there were a total of 1329 athletic-related shoulder dislocations that presented to participating EDs. Of these, 698 (52.5%) shoulder dislocations occurred in collegiate athletes, while 631 (47.5%) occurred in high school athletes. Using weighted and adjusted estimates automatically generated by the National Electronic Injury Surveillance System database, this translates to 89,511 total athletic-related shoulder dislocations across the United States (95% confidence interval lower bound 68,224; 95% confidence interval upper bound 110,798). Male athletes demonstrated a higher proportion of shoulder dislocations (87%) than female athletes (13%). The most common sport-specific mechanisms of traumatic shoulder dislocation were basketball (24.1%), football (21%), soccer (7.1%), baseball (7.1%), and weightlifting (3.3%). CONCLUSION: Sports-related shoulder dislocations are frequent in high school-aged and college-aged athletes presenting to the ED. Interventions to reduce incidence of injury should be sport-specific and focus on those participating in contact and noncontact sports. Male athletes have disproportionately higher rates of dislocation. These findings are consistent with the previous epidemiologic trends in the literature that have examined the incidence of shoulder dislocations in this population.

Outcomes of free vascularized fibular graft for post-traumatic osteonecrosis of the femoral head.

INTRODUCTION: Osteonecrosis of the femoral head (ONFH) can occur after traumatic injuries of the hip. Surgical treatment with total hip arthroplasty (THA) may not produce lifelong viability in younger patients. Free vascularized fibular graft (FVFG) has become a reliable method to delay or even avoid THA in this patient population by aiming to correct loss of viable bone through vascularized autologous bone transfer. The purpose of this study was to evaluate the longevity and outcomes of FVFG for traumatic hip injuries resulting in ONFH. METHODS: We performed a retrospective review of our institutional database of patients who had undergone FVFG from 1980-2006 for post-traumatic ONFH and had a minimum follow-up of 5 years. Data collected included demographics, pre-operative Urbaniak ONFH staging, Harris Hip scores (HHS), SF-12 scores, and conversion to THA. RESULTS: Seventy-two hips in 68 patients met inclusion criteria. Mean follow-up was 11.6 years (range 5.1-33.2 years). Etiology included femoral neck fracture in 36 patients (61%), hip dislocation in 7 (12%), trauma without fracture or dislocation in 11 (19%), and femoral neck nonunion in 5 (8%). The most common stage at presentation was stage IV (48 patients). Graft survival at final follow-up (mean 10.9 years) was 64%, with mean time to conversion to THA of 8.4 years in those that did not survive (36%). There was no difference between THA conversion rates in hips with pre-collapse (Stage I and II) versus impending or post-collapse (Stage III or IV) lesions (p = 0.227). In hips with surviving grafts at final follow-up, mean HHS improved from 56.7 to 77.3 (SD 24.57, range 69-93), a mean improvement of 20.6 (p < 0.001). CONCLUSIONS: Our study reveals improvement in HHS in surviving FVFG and an acceptable overall THA conversion rate at mid to long term follow-up in Urbaniak stage I through IV hips. FVFG remains a viable option for treatment in younger patients with pre- and post-collapse (stage IV) ONFH lesions secondary to hip trauma.

Malpractice trends in shoulder and elbow surgery.

BACKGROUND: Medical malpractice is a very common occurrence that many medical providers will have to face; approximately 17,000 medical malpractice cases are filed in the United States each year, and more than 99% of all surgeons are faced with at least 1 instance of malpractice litigation throughout their careers. Malpractice litigation also carries a major economic weight, with medical malpractice spending resulting in an aggregate expenditure of nearly $60 billion annually in the United States. Orthopedic surgery is one of the most common subspecialties involved in malpractice claims. Currently, there are no comprehensive studies examining malpractice lawsuits within shoulder and elbow surgery. Therefore, the purpose of this work is to examine trends in malpractice claims in shoulder and elbow surgery. METHODS: The Westlaw online legal database was queried in order to identify state and federal jury verdicts and settlements pertaining to shoulder and elbow surgery from 2010-2020. Only cases involving medical malpractice in which an orthopedic shoulder and elbow surgeon was a named defendant were included for analysis. All available details pertaining to the cases were collected. This included plaintiff demographic and geographic data. Details regarding the cases were also collected, such as anatomic location, pathology, complications, and case outcomes. RESULTS: Twenty-five malpractice lawsuits pertaining to orthopedic shoulder and elbow surgery were identified. Most plaintiffs in these cases were adult men, and the majority of cases were filed in the Southwest (28%) and Midwest (28%) regions of the United States. The most common anatomic region involved in claims was the rotator cuff (32%), followed by the glenohumeral joint (20%). The majority of these claims involved surgery (56%). Pain of mechanical nature was the most common complication seen in claims (56%). The jury ruled in favor of the defendant surgeon in most cases (80%). DISCUSSION: This is the first study that comprehensively examines the full scope of orthopedic shoulder and elbow malpractice claims across the United States. The most common complaint that plaintiffs reported at the time of litigation was residual pain after treatment due to a mechanical etiology, followed by complaints of nerve damage. A large portion of claims resulted after nonoperative treatment. A better understanding of the trends within malpractice claims is crucial to developing strategies for prevention.

Editorial Commentary: Ulnar Variance Is Not the Sole Determinant of Arthroscopic Wrist Triangular Fibrocartilage Complex Repair Outcome: Considering the Forest From the Ulnar-Positive Tree.

When choosing the best treatment option for patients with tears of the triangular fibrocartilage complex, there are multiple patient factors that should be carefully considered. The role of ulnar variance is often overemphasized when attempting to predict the success of arthroscopic repair. In practice, variables such as the age of the patient and location and nature of the tear as traumatic or degenerative should primarily drive the decision between arthroscopic repair and primary ulnar-shortening osteotomy. Arthroscopic repair should generally be avoided in favor of ulnar-shortening osteotomy in patients with degenerative tears and evidence of ulnar impaction syndrome. However, for acute, traumatic, ulnar-sided tears in young patients, arthroscopic repair remains an effective treatment option regardless of ulnar variance.

Currently Adopted Criteria for Pedicle Screw Diameter Selection.

BACKGROUND: Transpedicular screw insertion has become widely accepted for the correction of spinal deformity as well as degenerative and traumatic injury, but adoption of this technique has remained less widespread in the thoracic compared to the lumbar spine. This is thought to be associated with the relative technical difficulty of screw insertion into the narrower widths of the thoracic pedicles and the neurologic and mechanical risks associated with breach of the pedicle wall. The surgical decision making involves determining the appropriate sized screw for maximum fixation strength while simultaneously respecting the structural integrity of the vertebral pedicles to prevent a breach and provide better fixation. This paper presents a systematic review of criteria for thoracic pedicle screw diameter (SD) selection in order to orient inexperienced surgeons on the impact of this selection on pedicle breaching and fixation strength. METHODS: We performed a systematic literature review focused on studies reporting SD selection in relation to pedicle dimensions, measures of fixation strength, and breach rate. RESULTS: Twenty-nine articles that measured fixation strength, breach rate, and/or provided SD in relation to pedicle width were selected for inclusion. CONCLUSIONS: A commonly accepted criteria for pedicle SD selection has not yet been proposed. Screw diameters approximately 80% of the pedicle width have been adopted, but this proportion is rarely reported in the midthoracic vertebrae for which smaller pedicles and inadequate hardware specificity result in higher breach rates. Depending upon the insertion technique adopted, greater specificity in diameter selection by vertebral level should be pursued in order to maximally target cortical bone purchase. CLINICAL RELEVANCE: Based on this review of the literature, we believe that proper selection of the SD for individual vertebral level directly affects the insertion technique and the potential breach.

Gender Role in Total Knee Arthroplasty: A Retrospective Analysis of Perioperative Outcomes in US Patients.

BACKGROUND: Women present later than men for total knee arthroplasty (TKA) with more severe osteoarthritic disease but achieve comparable functional improvement and implant survival and also lower rates of revision. Despite these findings, there is significant underutilization of the procedure for women compared to men. METHODS: We conducted a retrospective study to address the lack of information in the literature concerning the immediate and short-term perioperative outcomes between genders. The National Hospital Discharge Survey was evaluated between 2001 and 2010 for men and women undergoing primary TKA in the United States. Differences in gender, patient demographics, comorbidities, complications, length of stay, and discharge disposition were analyzed and identified. RESULTS: The growth in TKA was 145% for men and 131% for women over the 10-year period. Women presented with significantly higher rates of obesity, morbid obesity, postoperative transfusion rate, and length of stay. In contrast, men showed a greater proportion of diabetes, postoperative wound infections, and increased mortality rates. Males were also more likely to be discharged to home, whereas females were more likely to be discharged to rehabilitation facilities. CONCLUSION: Our findings provide important insight into the perioperative outcomes that may be influencing gender disparity in TKA.

Voluntary and forced exercise differentially alters the gut microbiome in C57BL/6J mice.

We have previously shown that voluntary wheel running (VWR) attenuates, whereas forced treadmill running (FTR) exacerbates, intestinal inflammation and clinical outcomes in a mouse model of colitis. As the gut microbiome is implicated in colitis, we hypothesized that VWR and FTR would differentially affect the gut microbiome. Mice (9-10/treatment) were randomly assigned to VWR, FTR, or sedentary home cage control (SED) for 6 wk. VWR were given running wheel access, whereas FTR ran on a treadmill for 40 min/day at 8-12 m/min, 5% grade. Forty-eight hours after the last exercise session, DNA was isolated from the fecal pellets and cecal contents, and the conserved bacterial 16S rRNA gene was amplified and sequenced using the Illumina Miseq platform. Permutational multivariate analysis of variance based on weighted UniFrac distance matrix revealed different bacterial clusters between feces and cecal contents in all groups (P < 0.01). Interestingly, the community structures of the three treatment groups clustered separately from each other in both gut regions (P < 0.05). Contrary to our hypothesis, the α-diversity metric, Chao1, indicated that VWR led to reduced bacterial richness compared with FTR or SED (P < 0.05). Taxonomic evaluation revealed that both VWR and FTR altered many individual bacterial taxa. Of particular interest, Turicibacter spp., which has been strongly associated with immune function and bowel disease, was significantly lower in VWR vs. SED/FTR. These data indicate that VWR and FTR differentially alter the intestinal microbiome of mice. These effects were observed in both the feces and cecum despite vastly different community structures between each intestinal region.

Diet and exercise orthogonally alter the gut microbiome and reveal independent associations with anxiety and cognition.

BACKGROUND: The ingestion of a high-fat diet (HFD) and the resulting obese state can exert a multitude of stressors on the individual including anxiety and cognitive dysfunction. Though many studies have shown that exercise can alleviate the negative consequences of a HFD using metabolic readouts such as insulin and glucose, a paucity of well-controlled rodent studies have been published on HFD and exercise interactions with regard to behavioral outcomes. This is a critical issue since some individuals assume that HFD-induced behavioral problems such as anxiety and cognitive dysfunction can simply be exercised away. To investigate this, we analyzed mice fed a normal diet (ND), ND with exercise, HFD diet, or HFD with exercise. RESULTS: We found that mice on a HFD had robust anxiety phenotypes but this was not rescued by exercise. Conversely, exercise increased cognitive abilities but this was not impacted by the HFD. Given the importance of the gut microbiome in shaping the host state, we used 16S rRNA hypervariable tag sequencing to profile our cohorts and found that HFD massively reshaped the gut microbial community in agreement with numerous published studies. However, exercise alone also caused massive shifts in the gut microbiome at nearly the same magnitude as diet but these changes were surprisingly orthogonal. Additionally, specific bacterial abundances were directly proportional to measures of anxiety or cognition. CONCLUSIONS: Thus, behavioral domains and the gut microbiome are both impacted by diet and exercise but in unrelated ways. These data have important implications for obesity research aimed at modifications of the gut microbiome and suggest that specific gut microbes could be used as a biomarker for anxiety or cognition or perhaps even targeted for therapy.

Forced treadmill exercise training exacerbates inflammation and causes mortality while voluntary wheel training is protective in a mouse model of colitis.

The purpose of this study was to examine whether exercise training reduced inflammation and symptomology in a mouse model of colitis. We hypothesized that moderate forced treadmill running (FTR) or voluntary wheel running (VWR) would reduce colitis symptoms and colon inflammation in response to dextran sodium sulfate (DSS). Male C57Bl/6J mice were randomized to sedentary, moderate intensity FTR (8-12 m/min, 40 min, 6 weeks, 5x/week), or VWR (30 days access to wheels). DSS was given at 2% (w/v) in drinking water over 5 days. Mice discontinued exercise 24 h prior to and during DSS treatment. Colons were harvested on Days 6, 8 and 12 in FTR and Day 8 post-DSS in VWR experiments. Contrary to our hypothesis, we found that moderate FTR exacerbated colitis symptomology and inflammation as measured by significant (p<0.05) increases in diarrhea and IL-6, IL-1ß, IL-17 colon gene expression. We also observed higher mortality (3/10 died vs. 0/10, p=0.07) in the FTR/DSS group. In contrast, VWR alleviated colitis symptoms and reduced inflammatory gene expression in the colons of DSS-treated mice (p<0.05). While DSS treatment reduced food/fluid intake and body weight, there was a tendency for FTR to exacerbate, and for VWR to attenuate, this effect. FTR (in the absence of DSS) increased gene expression of the chemokine and antibacterial protein CCL6 suggesting that FTR altered gut homeostasis that may be related to the exaggerated response to DSS. In conclusion, we found that FTR exacerbated, whereas VWR attenuated, symptoms and inflammation in response to DSS.