Muscle damaging eccentric exercise attenuates disuse-induced declines in daily myofibrillar protein synthesis and transiently prevents muscle atrophy in healthy men.

Short-term disuse leads to muscle loss driven by lowered daily myofibrillar protein synthesis (MyoPS). However, disuse commonly results from muscle damage, and its influence on muscle deconditioning during disuse is unknown. Twenty-one males [20 ± 1 yr, BMI = 24 ± 1 kg·m-2 (± SE)] underwent 7 days of unilateral leg immobilization immediately preceded by 300 bilateral, maximal, muscle-damaging eccentric quadriceps contractions (DAM; subjects n = 10) or no exercise (CON; subjects n = 11). Participants ingested deuterated water and underwent temporal bilateral thigh MRI scans and vastus lateralis muscle biopsies of immobilized (IMM) and nonimmobilized (N-IMM) legs. N-IMM quadriceps muscle volume remained unchanged throughout both groups. IMM quadriceps muscle volume declined after 2 days by 1.7 ± 0.5% in CON (P = 0.031; and by 1.3 ± 0.6% when corrected to N-IMM; P = 0.06) but did not change in DAM, and declined equivalently in CON [by 6.4 ± 1.1% (5.0 ± 1.6% when corrected to N-IMM)] and DAM [by 2.6 ± 1.8% (4.0 ± 1.9% when corrected to N-IMM)] after 7 days. Immobilization began to decrease MyoPS compared with N-IMM in both groups after 2 days (P = 0.109), albeit with higher MyoPS rates in DAM compared with CON (P = 0.035). Frank suppression of MyoPS was observed between days 2 and 7 in CON (IMM = 1.04 ± 0.12, N-IMM = 1.86 ± 0.10%·day-1; P = 0.002) but not DAM (IMM = 1.49 ± 0.29, N-IMM = 1.90 ± 0.30%·day-1; P > 0.05). Declines in MyoPS and quadriceps volume after 7 days correlated positively in CON (r2 = 0.403; P = 0.035) but negatively in DAM (r2 = 0.483; P = 0.037). Quadriceps strength declined following immobilization in both groups, but to a greater extent in DAM. Prior muscle-damaging eccentric exercise increases MyoPS and prevents loss of quadriceps muscle volume after 2 (but not 7) days of disuse.NEW & NOTEWORTHY We investigated the impact of prior muscle-damaging eccentric exercise on disuse-induced muscle deconditioning. Two and 7 days of muscle disuse per se lowered quadriceps muscle volume in association with lowered daily myofibrillar protein synthesis (MyoPS). Prior eccentric exercise prevented the decline in muscle volume after 2 days and attenuated the decline in MyoPS after 2 and 7 days. These data indicate eccentric exercise increases MyoPS and transiently prevents quadriceps muscle atrophy during muscle disuse.

Biomechanical analysis of two runners who developed leg injuries during a six-week transition to maximal running shoes: A case series.

Achilles tendinopathy (AT) and medial tibial stress syndrome (MTSS) are two of the most common running-related injuries. In a previous study investigating running biomechanics before and after a six-week transition to maximal running shoes, two runners dropped out of this study due to Achilles pain and shin pain, respectively. The purpose of this case series was to investigate running biomechanics in those two runners, identifying potential causes for injury in relation to maximal shoe use. Running biomechanics were collected in a laboratory setting for these two runners wearing both a maximal running shoe and traditional running shoe before the six-week transition using an 8-camera motion capture system and two embedded force plates. Both runners displayed prolonged eversion in the maximal shoe, which has been previously cited as a potential risk factor for developing Achilles tendinopathy and medial tibial stress syndrome. Relatively high loading rates and impact forces were also observed in the runner with shin pain in the maximal shoe, which may have contributed to their pain. More prospective research on injury rates in individuals running in maximal shoes is needed.

Military Service Members with Major Lower Extremity Fractures Return to Running with a Passive-dynamic Ankle-foot Orthosis: Comparison with a Normative Population.

BACKGROUND: Lower extremity fractures represent a high percentage of reported injuries in the United States military and can devastate a service member's career. A passive dynamic ankle-foot orthosis (PD-AFO) with a specialized rehabilitation program was initially designed to treat military service members after complex battlefield lower extremity injuries, returning a select group of motivated individuals back to running. For high-demand users of the PD-AFO, the spatiotemporal gait parameters, agility, and quality of life is not fully understood with respect to uninjured runners. QUESTIONS/PURPOSES: Do patients who sustained a lower extremity fracture using a PD-AFO with a specialized rehabilitation program differ from uninjured service members acting as controls, as measured by (1) time-distance and biomechanical parameters associated with running, (2) agility testing (using the Comprehensive High-level Activity Mobility Predictor performance test and Four Square Step Test), and (3) the Short Musculoskeletal Function Assessment score. METHODS: We conducted a retrospective data analysis of a longitudinally collected data registry of patients using a PD-AFO from 2015 to 2017 at a single institution. The specific study cohort were patients with a unilateral lower extremity fracture who used the PD-AFO for running. Patients had to be fit with a PD-AFO, have completed rehabilitation, and have undergone a three-dimensional (3-D) running analysis at a self-selected speed at the completion of the program. Of the 90 patients who used the PD-AFO for various reasons, 10 male service members with lower extremity fractures who used a PD-AFO for running (median [range] age 29 years [22 to 41], height 1.8 meters [1.7 to 1.9], weight 91.6 kg [70 to 112]) were compared with 15 uninjured male runners in the military (median age 33 years [21 to 42], height 1.8 meters [1.7 to 1.9], weight 81.6 kg [71.2 to 98.9]). The uninjured runners were active-duty service members who voluntarily participated in a gait analysis at their own self-selected running speeds; to meet eligibility for inclusion as an uninjured control, the members had to be fit for full duty without any medical restrictions, and they had to be able to run 5 miles. The controls were then matched to the study group by age, weight, and height. The primary study outcome variables were the running time-distance parameters and frontal and sagittal plane kinematics of the trunk and pelvis during running. The Four Square Step Test, Comprehensive High-level Activity Mobility Predictor scores, and Short Musculoskeletal Function Assessment scores were analyzed for all groups as secondary outcomes. Nonparametric analyses were performed to determine differences between the two groups at p < 0.05. RESULTS: For the primary outcome, patients with a PD-AFO exhibited no differences compared with uninjured runners in median (range) running velocity (3.9 meters/second [3.4 to 4.2] versus 4.1 meters/second [3.1 to 4.8], median difference 0.2; p = 0.69), cadence (179 steps/minute [169 to 186] versus 173 steps/minute [159 to 191], median difference 5.8; p = 0.43), stride length (2.6 meters [2.4 to 2.9] versus 2.8 meters [2.3 to 3.3], median difference 0.2; p = 0.23), or sagittal plane parameters such as peak pelvic tilt (24° [15° to 33°] versus 22° [14° to 28°], median difference 1.6°; p = 0.43) and trunk forward flexion (16.2° [7.3° to 23°) versus 15.4° [4.2° to 21°), median difference 0.8°; p > 0.99) with the numbers available. For the secondary outcomes, runners with a PD-AFO performed worse in Comprehensive High-level Activity Mobility Predictor performance testing than uninjured runners did, with their four scores demonstrating a median (range) single-limb stance of 35 seconds (32 to 58) versus 60 seconds (60 to 60) (median difference 25 seconds; p < 0.001), t-test result of 15 seconds (13 to 20) versus 13 seconds (10 to 14) (median difference 2 seconds; p < 0.001), and Illinois Agility Test result of 22 seconds (20 to 25) versus 18 seconds (16 to 20) (median difference 4; p < 0.001). Edgren side step test result of 20 meters (16 to 26) versus 24 meters (16 to 29) (median difference 4 meters; p = 0.11) and the Four Square Step Test of 5.5 seconds (4.1 to 7.2) versus 4.2 seconds (3.1 to 7.3) (median difference 1.3 seconds; p = 0.39) were not different between the groups with an effect size of 0.83 and 0.75, respectively. CONCLUSION: The results of our study demonstrate that service members run with discernible differences in high-level mobility and demonstrate inferior self-reported patient functioning while having no differences in speed and biomechanics compared with their noninjured counterparts with the sample size available. This study is an early report on functional gains of highly motivated service members with major lower extremity injuries who use a PD-AFO and formalized therapy program to run. LEVEL OF EVIDENCE: Level III, therapeutic study.

Quantification of immobilization-induced changes in human calf muscle using speed-of-sound ultrasound: An observational pilot study.

ABSTRACT: Short-term immobilization leads to fatty muscular degeneration, which is associated with various negative health effects. Based on literature showing very high correlations between MRI Dixon fat fraction and Speed-of-Sound (SoS), we hypothesized that we can detect short-term-immobilization-induced differences in SoS.Both calves of 10 patients with a calf cast on one side for a mean duration of 41 ±â€Š26 days were examined in relaxed position using a standard ultrasound machine. Calf perimeters were measured for both sides. A flat Plexiglas-reflector, placed vertically on the opposite side of the probe with the calf in-between, was used as a timing reference for SoS. SoS was both manually annotated by two readers and assessed by an automatic annotation algorithm. The thickness values of the subcutaneous fat and muscle layers were manually read from the B-mode images. Differences between the cast and non-cast calves were calculated with a paired t test. Correlation analysis of SoS and calf perimeter was performed using Pearson's correlation coefficient.Paired t test showed significant differences between the cast and non-cast side for both SoS (P < .01) and leg perimeter (P < .001). SoS was reduced with the number of days after cast installment (r = -0.553, P = .097). No significant differences were found for muscle layer thickness, subcutaneous fat layer thickness, mean fat echo intensity, or mean muscle echo intensity.Short-term-immobilization led to a significant reduction in SoS in the cast calf compared to the healthy calf, indicating a potential role of SoS as a biomarker in detecting immobilization-induced fatty muscular degeneration not visible on B-mode ultrasound.

The Influence of Injury History on Countermovement Jump Performance and Movement Strategy in Professional Soccer Players: Implications for Profiling and Rehabilitation Foci.

CONTEXT: Professional soccer players who have sustained a lower limb injury are up to 3× more likely to suffer a reinjury, often of increased severity. Previous injury has been shown to induce compensatory strategies during neuromuscular screening tests, which might mask deficits and lead to misinterpretation of readiness to play based on task outcome measures. OBJECTIVE: To investigate the influence of previous injury in professional soccer players on countermovement jump (CMJ) performance and movement strategy. DESIGN: Cross-sectional. SETTING: Professional soccer club competing in the English Championship (tier 2). Patients (or Other Participants): Outfield players with a minimum of 6 years as a professional. INTERVENTION(S): Players were categorized as previously injured (n = 10) or not injured (n = 10). All players completed double- and single-leg CMJ trials. MAIN OUTCOME MEASURES: CMJ performance was quantified as jump height and flight time:contraction time ratio. CMJ movement strategy was quantified as force-time history, differentiating eccentric and concentric phases and CMJ depth. RESULTS: Double-leg CMJ was not sensitive to previous injury in performance or movement strategy. In contrast, single-leg CMJ performance was impaired in players with previous injury, who generated significantly lower eccentric and concentric peak force and rate of force development, and a deeper countermovement. Impaired single-leg CMJ performance was also evident in the nonaffected limb of previously injured players, suggesting cross-contamination. Hierarchical ordering revealed that the eccentric phase of the CMJ contributed little to performance in previously injured players. In noninjured players, the eccentric rate of force development and concentric peak force were able to account for up to 89% of the variation in CMJ performance. CONCLUSIONS: Single-leg CMJ is advocated for player profiling, being more sensitive to previous injury, and negating the opportunity for interlimb compensation strategies. Movement strategy deficits in previously injured players suggest rehabilitation foci specific to eccentric force development.

Symmetry does not Indicate Recovery: Single-leg Hop Before and After a Lower Extremity Injury.

Current recommendations for return-to-play decision-making involve comparison of the injured limb to the uninjured limb. However, the use of the uninjured limb as a comparison for hop testing lacks empirical evidence. Thus, the purpose of this study was to determine the effects of lower extremity injury on limb symmetry and performance on the single-leg hop for distance. Two-hundred thirty-six adolescent athletes completed the single-leg hop for distance before the beginning of the season (pre-injury). Forty-four adolescent athletes sustained a lower extremity injury (22 ankle and 12 knee) and missed at least three days of sports participation. All individuals had completed the single-leg hop for distance before the beginning of the season (pre-injury) and at discharge (post-injury). Injured limb single-leg hop for distance significantly decreased at return-to-play from pre-injury with a mean decrease of 48.9 centimeters; the uninjured limb also significantly decreased, with a mean decrease of 33.8 centimeters. Limb symmetry did not significantly change pre- to post-injury with a mean difference of 1.5%. Following a lower extremity injury, single-leg hop for distance performance degrades not only for the injured limb but also the uninjured limb. However, limb symmetry did not change following a lower extremity injury.

Use of double leg injury screening to assess single leg biomechanical risk variables.

OBJECTIVES: The purpose of this article was to determine if differences in kinematic and kinetic variables observed in a double-leg screen carried over to a single-leg task. DESIGN: We used a case-control design with grouping based on performance during a double-leg jump landing. SETTING: All participants were selected from a large university setting and testing was performed in a biomechanics laboratory. PARTICIPANTS: Participants were females between 18 and 25 years of age with at least high school varsity experience in one or more of the following sports: soccer, lacrosse, field hockey, rugby, basketball, or team handball. MAIN OUTCOME MEASURES: Primary outcome measures were knee angles in the frontal and sagittal planes as well as vertical ground reaction force (vGRF). RESULTS: There were significant between group differences in peak knee flexion and knee flexion displacement during both the double and single-leg tasks, however between group differences for peak knee valgus and knee valgus displacement noted in the double-leg task were not observed in the single-leg task. vGRF was significantly different in the single-leg task but not the double-leg task. CONCLUSION: A double leg screening may not provide complete identification of risk of injury during sports requiring single leg tasks.

Management of Lower Extremity Fractures in the Elderly: A Focus on Post-Operative Rehabilitation.

Fractures in the elderly population are increasing in incidence and represent a rising burden of disease. It is difficult for the elderly population to adhere to restricted weight bearing, and immobility poses significant risks and increased morbidity. Therefore, a primary goal of fracture management in the elderly population is early post-operative weight bearing. This review examines published literature regarding lower extremity fracture management in the elderly, with a focus on post-operative rehabilitation. While extensive literature supports early weight bearing after hip fractures in the elderly, further research is warranted to provide guidelines for management of other lower extremity fractures in this population.

Can the Y balance test identify those at risk of contact or non-contact lower extremity injury in adolescent and collegiate Gaelic games?

OBJECTIVES: Lower extremity (LE) injuries are common in Gaelic games and lead to a significant economic and injury burden. Balance is considered a predictor of injury in other sports, however no research has examined its effect on LE injury in Gaelic games. This study aims to present normative data for the Y Balance Test (YBT), determine whether the YBT can identify those at risk of contact and non-contact LE and ankle injuries and generate population specific cut-off points in adolescent and collegiate Gaelic games. DESIGN: Prospective cohort study. METHODS: A convenience sample of 636 male adolescent (n=293, age=15.7±0.7 years) and collegiate (n=343, age=19.3±1.9 years) Gaelic footballers and hurlers were recruited. The YBT was completed and injuries were assessed at least weekly over one season. Univariate and logistic regression was performed to examine if the YBT can classify those at risk of LE-combined and ankle injuries. ROC curves were used to identify cut-off points. RESULTS: Gaelic players performed poorly in the YBT and between 31-57% of all players were identified as at risk of injury at pre-season using previously published YBT cut-off points. However, poor YBT scores were unable to ascertain those at risk of contact or non-contact LE-combined and ankle injuries with sufficient sensitivity. High specificity was noted for contact LE-combined and non-contact ankle injuries. CONCLUSIONS: The YBT as a sole screening method to classify those at risk of LE and ankle injuries in Gaelic games is questionable. However, the YBT may be a useful preliminary screening tool to identify those not at risk of contact LE-combined or non-contact ankle injury. Generalising published cut-off points from other sports is not supported.

A scoping review of non-linear analysis approaches measuring variability in gait due to lower body injury or dysfunction.

OBJECTIVES: The aim of this review is to evaluate and summarize existing literature using non-linear analysis methodology to consider variability of human movement due to lower limb injury or dysfunction. DESIGN: Scoping review. METHODS: An electronic keyword search was performed on three databases to identify appropriate research. This research was then examined for details of measures and methodology, use of control groups and general study characteristics to identify related themes. RESULTS: Fifteen papers were reviewed and synthesized. A range of conditions were studied, mainly affecting knee and ankle joints, and each using different non-linear methods and different equipment (motion capture, accelerometry, and muscle activation) to evaluate the mathematically chaotic nature of the movement and assess the variability in gait. Sample sizes and effect sizes are commonly small in these studies. CONCLUSIONS: Non-linear analysis is a potentially useful tool in both diagnosis and evaluation of injury, and this should inform future clinical processes when dealing with injury and movement variability. Despite numerous studies evaluating neurological conditions and ageing, focus on injury is limited, with notable gaps in terms of considering other joints and joint actions, so this should be a promising area of research to develop our understanding of injury and rehabilitation and how this affects gait variability.

Could an isolated human body lower limb model predict leg biomechanical response of Chinese pedestrians in vehicle collisions?

PURPOSE: The purpose of the current study was to investigate whether an isolated human body lower limb FE model could predict leg kinematics and biomechanical response of a full body Chinese pedestrian model in vehicle collisions. METHODS: A human body lower limb FE model representing midsize Chinese adult male anthropometry was employed with different upper body weight attachments being evaluated by comparing the predictions to those of a full body pedestrian model in vehicle-to-pedestrian collisions considering different front-end shapes. RESULTS: The results indicate that upper body mass has a significant influence on pedestrian lower limb injury risk, the effect varies from vehicle front-end shape and is more remarkable to the femur and knee ligaments than to the tibia. In particular, the upper body mass can generally increase femur and knee ligaments injury risk, but has no obvious effect on the injury risk of tibia. The results also show that a higher attached buttock mass is needed for isolated pedestrian lower limb model for impacts with vehicles of higher bonnet leading edge. CONCLUSIONS: The findings of this study may suggest that it is necessary to consider vehicle shape variation in assessment of vehicle pedestrian protection performance and leg-form impactors with adaptive upper body mass should be used for vehicles with different front-end shapes, and the use of regional leg-form impactor modeling the local anthropometry to evaluate the actual lower limb injury of pedestrians in different countries and regions.

Physical Activity and Sedentary Behavior 6 Months After Musculoskeletal Trauma: What Factors Predict Recovery?

BACKGROUND: Physical activity is increasingly recognized as an important marker of functional recovery following fracture. OBJECTIVE: The objectives of this study were to measure sedentary behavior and physical activity 2 weeks and 6 months following fracture and to determine associated demographic and injury factors. DESIGN: This was an observational study. METHODS: Two weeks and 6 months following fracture, 83 adults who were 18 to 69 years old and had upper limb (UL) or lower limb (LL) fractures wore an accelerometer and an inclinometer for 10 days. We calculated sitting time, steps, moderate-intensity physical activity (MPA), and vigorous-intensity physical activity and conducted linear mixed-effects multivariable regression analyses to determine factors associated with temporal changes in activity. RESULTS: At 6 months versus 2 weeks after fracture, participants sat less, took more steps, and engaged in more MPA. Participants with LL fractures sat 2 hours more, took 66% fewer steps, and engaged in 77% less MPA than participants with UL fractures. Greater reductions in sitting time were observed for participants in the youngest age group and with LL fractures, participants with high preinjury activity, and participants who were overweight or obese. For steps, greater improvement was observed for participants in the youngest and middle-aged groups and those with LL fractures. For MPA, greater improvement was observed for middle-aged participants and those with LL fractures. LIMITATIONS: Although this study was sufficiently powered for the analysis of major categories, a convenience sample that may not be representative of all people with musculoskeletal trauma was used. CONCLUSIONS: Working-age adults with LL fractures had lower levels of physical activity 6 months after fracture than those with UL fractures. Older adults showed less improvement over time, suggesting that they are an important target group for interventions aimed at regaining preinjury activity levels.

Correlating clinical assessment and MRI findings in diagnosing calf injuries in elite male Australian rules footballers.

OBJECTIVE: Calf complex injuries represent a significant injury burden among Australian Rules athletes. To date, there has been limited research correlating clinical and radiological findings of pathology within the calf. The objective of this study is to determine how accurately magnetic resonance imaging (MRI) findings correlate with clinical measures of calf muscle complex pathology in elite male athletes. MATERIALS AND METHODS: A prospective cohort study was conducted on Australian rules elite athletes. A cohort of 45 athletes underwent a high-load training session of approximately 10 km of running. Athletes were then assessed by a sports physiotherapist who made a diagnosis of no pathology, delayed onset muscle soreness, strain or other. Subsequently, the athletes underwent MRI of their bilateral calf complexes. Radiologists interpreted the MRI findings and radiological diagnosis were correlated with clinical diagnosis. RESULTS: A total of 90 calf MRIs were performed. Correlation of clinical and radiological diagnosis occurred in 57 cases. Of the 33 cases which did not correlate, there were 4 radiologically significant acute calf strains in clinically asymptomatic athletes, 3 of which involved old scar tissue. CONCLUSION: MRI may detect clinically insignificant injuries within the calf complex. If an athlete does not have any clinically relevant symptoms, abnormal signal on MRI may represent a different diagnosis to muscle strain. Signal change on MRI proximal to scar tissue may represent reactive oedema. Clinical history and examination should be correlated with radiological findings is recommended when diagnosing calf injury in elite athletes.

Thromboprophylaxis in lower limb immobilisation after injury (TiLLI).

Venous thromboembolic disease is a major global cause of morbidity and mortality. An estimated 10 million episodes are diagnosed yearly; over half of these episodes are provoked by hospital admission/procedures and result in significant loss of disability adjusted life years. Temporary lower limb immobilisation after injury is a significant contributor to the overall burden of venous thromboembolism (VTE). Existing evidence suggests that pharmacological prophylaxis could reduce overall VTE event rates in these patients, but the proportional reduction of symptomatic events remains unclear. Recent studies have used different pharmacological agents, dosing regimens and outcome measures. Consequently, there is wide variation in thromboprophylaxis strategies, and international guidelines continue to offer conflicting advice for clinicians. In this review, we provide a summary of recent evidence assessing both the clinical and cost effectiveness of thromboprophylaxis in patients with temporary immobilisation after injury. We also examine the evidence supporting stratified thromboprophylaxis and the validity of widely used risk assessment methods.

Excellent clinical outcome and low complication rate after proximal hamstring tendon repair at mid-term follow up.

PURPOSE: Proximal hamstring tendon avulsions lead to a significant loss of strength and a functional deficit of the respective lower limb and surgery is the recommended treatment. Only little is known about the clinical outcomes and complications when comparing acute and chronic management as well as partial and complete tears. Therefore, the purpose of this study was to investigate the clinical results and the complication rate of patients after surgical treatment of proximal hamstring tendon injuries. It was hypothesized that surgical treatment of an acute proximal hamstring avulsion would lead to a superior clinical outcome with a low complication rate and high return to sports rate compared to chronic cases and partial avulsions. METHODS: Patients who underwent proximal hamstring tendon repair between 2008 and 2015 were retrospectively evaluated with a minimum follow up of 2 years. Outcome measurements were obtained by means of Lysholm score, Harris Hip Score, Visual Analog Scale, and Tegner Activity Scale. Return to sports (RTS) rate was determined. Postoperative adverse events were recorded and complications reported. Patients' outcomes were compared between acute/chronic repair and partial/complete injury patterns. RESULTS: Ninety-four of 120 (78.3%) were available for final assessment at a mean follow-up of 56.2 ± 27.2 months. Clinical outcome measures were excellent and did not differ between the treatment groups or between the different injury patterns. RTS was achieved by 86.2% of the patients and was significantly superior after acute treatment (p < 0.05). The overall complication rate was 8.5% and significantly higher in complete tears compared to partial tears and in delay compared to acute surgery (p < 0.05). CONCLUSION: Surgical treatment of proximal hamstring tendon avulsions results in excellent clinical outcome scores and a high RTS rate. Open surgical treatment has shown to be a safe procedure with a low complication rate. Surgical timing is important, as early surgical intervention provides a higher RTS rate and a lower complication rate than delayed surgery and should therefore be preferred in clinical practice. Repair of partial and complete tears lead to similar clinical outcome, but a higher complication rate in complete avulsions. LEVEL OF EVIDENCE: Level IV.

Pulmonary embolism occurring early after major trauma.

Pulmonary embolism (PE) secondary to trauma is the third most common cause of death in trauma patients who have survived 24 hours following injury. We describe a case of PE diagnosed within 3 hours of a major trauma in a previously well adolescent female. The early occurrence of PE in this case is at odds with what is generally reported (3-5 days) after major trauma. General consensus is that patients who suffer major trauma move from an initial hypocoaguable state, with increased risk of bleeding, to normocoagulable or hypercoaguable state, with a subsequent increased risk of venothromboembolism. However, Sumislawski et al recently demonstrated that a marginally greater proportion of trauma patients were in fact hypercoaguable rather than hypocoaguable on arrival to hospital and that trauma-induced coagulopathy tended to resolve within 24 hours; such data cause us to re-evaluate when to commence thromboprophylaxis for major trauma patients.

Venous thromboembolism rates remained unchanged in operative lower extremity orthopaedic trauma patients from 2008 to 2016.

BACKGROUND: Venous thromboembolism (VTE) is a serious complication that contributes to morbidity, mortality, and healthcare costs during the surgical care of patient with lower extremity fractures. Despite this, few recommendations on the topic exist and the literature on VTE incidence is incomplete. Therefore, this study will attempt to estimate annual incidence and trends in 30-day thrombotic events and mortality for the following fractures: (1) hip, (2) femur, (3) patella, (4) tibia and/or fibula, and (5) ankle. METHODS: We identified 120,521 operative lower extremity orthopaedic trauma patients from 2008 to 2016 using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. To evaluate the relationship between the year in which surgery was performed and comorbidities and demographic information bivariate analysis was performed. Bivariate analysis was also performed for the outcomes of interest and year in which the surgery was performed to assess for change. Additionally, bimodal multivariate logistic regression models for hip, femur, and ankle fractures were built, comparing the years 2009 to 2016 using 2008 as a baseline. RESULTS: Overall incidence for VTE over the study period was 1.7% for hip fractures, 2.4% for femur fractures, 0.9% for patella fractures, 1.1% in tibia and/or fibula fractures, and 0.6% in ankle fractures. Over the study period VTE incidence saw a significant decrease (p < 0.05) in hip and femur fractures, but not for patella, tibia and/or fibula, and ankle fractures. After adjusting for confounding factors with multivariate analysis, the change in hip and femur fractures was no longer significant, while no significant decrease was again found for ankle fractures (p > 0.05). CONCLUSION: Our study demonstrates that VTE rates have remained unchanged in operative lower extremity orthopaedic trauma from 2008 to 2016. This highlights the need for higher quality evidence on this important topic in orthopaedic trauma, including a reevaluation on the necessity of thromboprophylaxis guidelines. LEVEL OF EVIDENCE: III.

Vacuum-Assisted Wound Closure Therapy in Pediatric Lower Limb Trauma.

Although the importance of vacuum-assisted wound closure therapy has been well established as road to definitive treatment of trauma wound in the adult population, its use in pediatric patients is not well described in the literature. This study was conducted to evaluate the outcome of vacuum-assisted wound closure therapy in pediatric patients. Twenty-two patients were prospectively treated for soft tissue defect in lower limb using vacuum-assisted wound closure device, as these wounds were not amenable for primary closure. After wound evaluation, thorough wound debridement was done. Vacuum-assisted wound closure dressing was applied once hemostasis was achieved. Dressings were changed as per protocol. After the development of healthy granulation tissue, wound coverage was achieved with skin graft or flaps. Mean age of patients was 9.455 years, ranging from 4 to 14 years. Early, healthy granulation tissue had formed in all patients. The average number of vacuum-assisted closure (VAC) dressings required was 2.682. Average duration of VAC therapy was 8.045 days. The sizes of soft tissue defects reduced from an average 69.18 cm2 to 50.73 cm2 after VAC therapy with a mean decrease of 26.66%. There was no complication because of VAC therapy. Vacuum-assisted wound closure therapy accelerated the process of healthy granulation tissue formation, and thus shortened the healing time. VAC therapy lessens the morbidity and pain associated with large wounds in pediatric patients and brings cheer and smile in growing children.

Advanced Functional Bracing in Lower Extremity Trauma: Bracing to Improve Function.

There are many bracing options for patients with functional limitations of the lower extremity following trauma. The first question that the provider must ask when evaluating a patient with a foot and ankle functional limitation because of weakness or pain is, "what are the patient's expectations?" One option for the patient who desires to return to a higher level of function is a novel, custom dynamic orthosis (CDO) that, when coupled with an advanced rehabilitation program, has improved outcomes in patients following lower extremity trauma who have plateaued after traditional rehabilitation pathways. Although this CDO and rehabilitation program has demonstrated success following lower extremity trauma in heterogenous patient populations, research is ongoing to identify both ideal referral diagnoses or injury characteristics, and to further optimize outcomes with the use of the CDO.

A retrospective analysis of hamstring injuries in elite rugby athletes: More severe injuries are likely to occur at the distal myofascial junction.

OBJECTIVES: To describe the most common hamstring injury scenarios and outcomes in elite rugby union. DESIGN: Retrospective investigation. SETTING: Hamstring injury data from an elite rugby union team was collected over five seasons and retrospectively analysed. PARTICIPANTS: 74 professional rugby players. MAIN OUTCOME MEASURES: Injuries were classified as new or recurrent. Injury severity, activity, player position, and whether the injury occurred during a match or training was determined for each injury. Injury location and grade were determined for more clinically severe injuries where Magnetic Resonance Imaging (MRI) data was available (15 injuries). RESULTS: Thirty hamstring injuries were sustained over the five seasons. The majority of injuries were new (93%), moderate in severity (60%) and occurred during running (77%). For more clinically severe injuries, the biceps femoris long head (BFlh) was the most commonly injured muscle (73%) and the distal myofascial junction (DMFJ) was the most common injury site (58% of BFlh injuries). CONCLUSIONS: Hamstring injuries most commonly occurred while running and in the BFlh muscle, which is similar to other sports. However, the most common intramuscular injury site was the DMFJ, which contrasts with reports from other cohorts. Future studies should ensure to include the myofascial junction when classifying injury location.