Immobilization of laccase on magnetic PEGDA-CS inverse opal hydrogel for enhancement of bisphenol A degradation in aqueous solution

Endocrine disruptors such as bisphenol A (BPA) adversely affect the environment and human health. Laccases are used for the efficient biodegradation of various persistent organic pollutants in an environmentally safe manner. However, the direct application of free laccases is generally hindered by short enzyme lifetimes, non-reusability, and the high cost of a single use. In this study, laccases were immobilized on a novel magnetic three-dimensional poly(ethylene glycol) diacrylate (PEGDA)-chitosan (CS) inverse opal hydrogel (LAC@MPEGDA@CS@IOH). The immobilized laccase showed significant improvement in the BPA degradation performance and superior storage stability compared with the free laccase. 91.1% of 100 mg/L BPA was removed by the LAC@MPEGDA@CS@IOH in 3 hr, whereas only 50.6% of BPA was removed by the same amount of the free laccase. Compared with the laccase, the outstanding BPA degradation efficiency of the LAC@MPEGDA@CS@IOH was maintained over a wider range of pH values and temperatures. Moreover, its relative activity of was maintained at 70.4% after 10 cycles, and the system performed well in actual water matrices. This efficient method for preparing immobilized laccases is simple and green, and it can be used to further develop ecofriendly biocatalysts to remove organic pollutants from wastewater.

Pain, function and peritendinous effusion improvement after dry needling in patients with long head of biceps brachii tendinopathy: a single-blind randomized clinical trial

INTRODUCTION

Long head of biceps brachii tendinopathy, a frequent source of anterior shoulder pain, may lead to discomfort and diminished function. The objective of this study is to assess the efficacy of dry needling and transcutaneous electrical nerve stimulation in these patients.

PATIENTS AND METHODS

Thirty patients were randomized into dry needling and transcutaneous electrical nerve stimulation groups and assessed before treatment, 8 and 15 days after treatment using a visual analogue scale, shoulder pain and disability index, pressure pain threshold, tissue hardness, and biceps peritendinous effusion.

RESULTS

Both treatments significantly reduced the visual analogue scale in immediate (p < 0.001), short-term (p < 0.01), and medium-term effects (p < 0.01). Dry needling outperformed transcutaneous electrical nerve stimulation for the pain (p < 0.01) and disability (p < 0.03) subscales of the shoulder pain and disability index in the short-term and medium-term effects, respectively. Pressure pain threshold increased after both treatments but didn't last beyond 8 days. Neither treatment showed any improvements in tissue hardness of the long head of biceps brachii muscle. Notably, only the dry needling group significantly reduced biceps peritendinous effusion in both short-term and medium-term effects (p < 0.01).

CONCLUSIONS

Dry needling showed non-inferior results to transcutaneous electrical nerve stimulation in reducing pain and disability and demonstrated even superior results in reducing biceps peritendinous effusion (see Graphical Abstract).

TRIAL REGISTRATION

The Institutional Review Board of the China Medical University Hospital (CMUH107-REC2-101) approved this study, and it was registered with Identifier NCT03639454 on ClinicalTrials.gov.

Promotion of hMDSC differentiation by combined action of scaffold material and TGF-β superfamily growth factors

Objective

Herein we propose a combined action of collagen type I (CA) or synthetic collagen-like-peptide functionalized with the cell adhesive RGD motif (PEG-CLP-RGD) hydrogels and selected growth factors to promote chondrogenic differentiation of human muscle-derived stem cells (hMDSCs) under normal and reduced oxygen conditions.

Methods

hMDSCs were set for differentiation towards chondrogenic lineage using BMP-7 and TGF-β3. Cells were seeded onto hydrogels loaded with growth factors (75ng/scaffold) and cultured for 28 days under normal (21%) and severe hypoxic (1%) conditions. Chondrogenesis was evaluated by monitoring collagen type II and GAG deposition, and quantification of ACAN expression by RT-PCR.

Results

Sustained release of TGFβ3 from the hydrogels was observed, 8.7 ± 0.5% of the initially loaded amount diffused out after 24 h from both substrates. For the BMP-7 growth factor, 14.8 ± 0.3% and 18.2 ± 0.6% of the initially loaded amount diffused out after 24 h from CA and CLP-RGD, respectively. The key findings of this study are: i) the self-supporting hydrogels themselves can stimulate hMDSC chondrogenesis by inducing gene expression of cartilage-specific proteoglycan aggrecan and ECM production; ii) the effect of dual BMP-7 and TGF-β3 loading was more pronounced on CA hydrogel under normal oxygen conditions; iii) dual loading on PEG-CLP-RGD hydrogels did not have the synergistic effect, TGF-β3 was more effective under both oxygen conditions; iv) BMP-7 can improve chondrogenic effect of TGF-β3 on CA scaffolds, and hydrogels loaded with both growth factors can induce cartilage formation in hMDSC cultures.

Conclusion

Our results support the potential strategy of combining implantable hydrogels functionalized with differentiation factors toward improving cartilaginous repair.

Time-based changes in authorship trend in research-intensive universities in Malaysia

Considering the fact that publications serve as an important criterion to evaluate the scientific accomplishments of an individual within respective fields in academia, there has been an increasing trend to publish scientific articles whereby multiple authors are defined as primary, co-, or corresponding authors according to the roles performed. This article analyzes the authorship pattern in 4,561 papers (including 60 single-authored papers) from 1990 till 2020 of 94 academics who hold a position as professors and are affiliated with the Faculty of Medicine at three different research universities in Malaysia. Only 708 papers (15.5% of 4,561 papers) were authored by less than three authors. In 3,080 papers (67.5% of 4,561 papers), those academics appeared as coauthors. Using different years as cutoff periods, it was observed that the appearance as coauthor in the papers had steeply risen around the years: 2006, 2007, 2008 and onwards. The increased number of authors in the multi-author papers and the appearance of the selected academics as coauthors reflect the extent of boosting of collaborative research in that period which corresponds to the adoption of the "publish or perish policy" by the Ministry of Higher Education in Malaysia.

A bibliometric analysis of the top 50 cited studies related to acromioclavicular joint instability

Background

Acromioclavicular joint (ACJ) injury is a common orthopaedic condition accounting for over 40 % of all shoulder injuries. The purpose of this study is to assess the research trends and characteristics of the top 50 cited articles on ACJ instability.

Methods

A systematic search was conducted in Web of Science to identify articles primarily related to ACJ injury or instability. Characteristics including citation number, country of origin, journal and institution of publication, impact factor, authorship, level of evidence, patient demographics, and study type were analyzed and recorded.

Results

Research output on ACJ instability has been steadily increasing, with the top 50 cited studies predominantly presenting Level IV evidence. These studies primarily focused on treatment outcomes which included predominantly male patients and exhibited a large variation in citation counts. The American Journal of Sports Medicine was the most productive journal, and the USA was the most productive nation.

Conclusion

There is an increasing number of publications in the ACJ instability literature, primarily concentrated in a few institutions and journals, and focusing mainly on treatment outcomes. A significant portion of these publications are of low scientific quality, and there is a notable lack of research on outcomes for females.

The Application of Self-Made Disseminating and Descending Breathing Exercises in Home Rehabilitation of Stable COPD

To investigate the clinical effects and application value of self-made disseminating and descending breathing exercises on home rehabilitation of patients with stable chronic obstructive pulmonary disease (COPD). Seeking to generate concepts for creating novel, convenient, and efficient COPD prognosis rehabilitation exercises aimed at enhancing the well-being and rehabilitation confidence of both COPD patients and their families. A total of 70 COPD patients admitted to our outpatient department from July 2019 to September 2021 were randomly divided into the exercise group (n = 35) and the control group (n = 35). The control group received routine breathing training, while the exercise group was treated with self-made disseminating and descending breathing exercises. The respiratory function, including pulmonary function (FVC, FEV1, FEV1/FVC) and respiratory muscle strength (MIP, MEP), exercise tolerance (6-min walking distance, 6MWT), Modified Medical Research Council Dyspnea Scale (mMRC, Borg), COPD quality of life score (CAT, SGRQ), anxiety and depression scores (HAMA, HAMD) were compared between the two groups after 12-week exercise. After 12-week training, the FEV1, MIP, and MEP in the exercise group were significantly higher than those in the control group (p < 0.001), and the 6MWT was significantly increased in the exercise group compared to the control group (p < 0.001); while the mMRC, Borg score, the scores of CAT, SGRQ, HAMA, and HAMD were found significantly lower than those in the control group (p < 0.001). The self-made disseminating and descending breathing exercises can improve respiratory function and reduce symptoms of dyspnea in COPD patients, while enhancing exercise tolerance and relieving anxiety and depression, and are worthy of clinical application.

Headgear mandates in high school girls' lacrosse: investigating differences in impact rates and game play behaviors

BACKGROUND/OBJECTIVE

Headgear designed to protect girls' lacrosse athletes is widely available and permitted for voluntary use; however, it remains unknown how policies mandating headgear use may change the sport and, particularly regarding impacts during game-play. Therefore, this study compares the impact rates and game play characteristics of girls' high school lacrosse in Florida which mandates headgear use (HM), with states having no headgear mandate (NHM).

MATERIALS AND METHODS

Video from 189 randomly-selected games (HM: 64, NHM: 125) were analyzed. Descriptive statistics, Impact Rates (IR), Impact Rate Ratios (IRR), Impact Proportion Ratios (IPR), and 95% Confidence Intervals (CI) were calculated. IRRs and IPRs with corresponding CIs that excluded 1.00 were deemed statistically significant.

RESULTS

16,340 impacts (HM:5,821 NHM: 10,519; 86.6 impacts/game, CI: 88.6-93.3) were identified using the Lacrosse Incident Analysis Instrument (LIAI). Most impacts directly struck the body (n = 16,010, 98%). A minority of impacts directly struck a player's head (n = 330, 2%). The rate of head impacts was significantly higher in the HM cohort than NHM cohort (IRR = 2.1; 95% CI = 1.7-2.6). Most head impacts (n = 271, 82%) were caused by stick contact in both groups. There was no difference in the proportion of penalties administered for head impacts caused by stick contact between the HM and NHM cohorts (IPR IRRHM/NHM = 0.98; CI = 0.79-1.16). However, there was a significantly greater proportion of head impacts caused by player contact that resulted in a penalty administered in the HM cohort (IPR = 1.44 CI = 1.17-1.54).

CONCLUSION

These findings demonstrate that mandating headgear use was associated with a two-fold greater likelihood of sustaining a head impact during game play compared to NHM states. A majority of head impacts in both HM and NHM states were caused by illegal stick contact that did not result in penalty.

Applications of blood plasma derivatives for cutaneous wound healing: A mini-review of clinical studies

Skin injuries are a global healthcare problem. Chronic ulcers do not heal in a timely fashion, so it is essential to help the body with skin repair. There are some treatments that have been applied to chronic ulcers. One of these treatments is growth factor (GF) therapy. Platelet-rich plasma (PRP) and Platelet-poor plasma (PPP) are two types of plasma derivatives containing many GFs important for wound healing. Several works have reported their application in wound healing and tissue regeneration. The use of autologous PRP is now an adequate alternative in regenerative medicine. It was also demonstrated that PPP is a hemostatic agent for wounds. This review has studied the latest clinical studies, which have applied PRP and PPP to patients with chronic wounds.

Comparison of bioactive substances in novel-developed freeze-dried platelet-rich plasma (PRP) and activated normal PRP, and investigation of bioactive substance levels after long-term storage

Introduction

In recent years, biotherapy in orthopedics has become widespread, and platelet-rich plasma (PRP) has been readily used to treat sports injuries and osteoarthritis. Production of freeze-dried PRP (PRP-FD) results in PRP that is in powder form, allowing it to be stored for long periods at room temperature. Using this technology, we have developed Valuable Platelet-Derived Factor Concentrate Freeze Dry (VFD). However, whether VFD contains sufficient levels of bioactive substances (BS) remains unknown and retains the same levels of BS during long-term storage. In this study, we examined whether VFD contains sufficient amounts of BS and whether they retain these BS levels during long-term storage.

Methods

Peripheral blood was collected from 10 healthy men (mean ± SD: 46.5 ± 15 years old) and various BS, including transforming growth factor β (TGF-β), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), tissue inhibitors of metalloproteinases-1 (TIMP-1), interleukin-1 receptor antagonist (IL-1ra), matrix metallopeptidase-9 (MMP-9), and interleukin-6 (IL-6), were compared between VFD and normal PRP samples, including both leukocyte-rich PRP (LR-PRP) and leukocyte-poor PRP (LP-PRP). VFD was prepared using two rounds of centrifugation. LP-PRP and LR-PRP were activated by freezing and thawing before measurement. To evaluate the effects of long-term storage, the BS of VFD purified from five professional football players was compared between baseline and 1 year after storage.

Results

In terms of the growth factors, the TGF-β and EGF levels were higher in LR-PRP than in VFD and LP-PRP (p < 0.05), while the bFGF levels were higher in VFD than in the LR-PRP and LP-PRP groups (p < 0.01). In terms of anti-inflammatory cytokines, the TIMP-1 level was lower in VFD than that in the other groups (p < 0.01), whereas the IL-1ra levels were higher in VFD than those in LP-PRP (p < 0.05) and lower than those in LR-PRP (p < 0.01). In terms of inflammatory enzymes and cytokines, the IL-1ra level was higher in VFD than that in LP-PRP (p < 0.05) and lower than that in LR-PRP (p < 0.01), whereas the IL-6 levels did not differ among the groups. Furthermore, the TGF-β, bFGF, TIMP-1, and IL-1ra levels were 5.61 → 3.38 (x103 pg/μL), 61.0 → 63.0 (pg/μL), 3.4 → 2.7 (x105 pg/μL), and 14.9 → 14.5 (x103 pg/μL) at baseline and 1 year later, respectively. No significant differences in the BS levels were observed between baseline and 1 year after storage.

Conclusions

The VFD samples prepared in this study exhibited higher levels of anti-inflammatory cytokines than LP-PRP and contained growth factor levels similar to LP-PRP and LR-PRP. In addition, the BS levels in VFD samples were maintained after one year of storage. These results suggest that VFD can be prepared and stored and may serve as a novel treatment strategy for sports injuries in high-risk groups, such as athletes.

Safe2Play in youth ice hockey: injury profile and risk factors in a 5-year Canadian longitudinal cohort study

INTRODUCTION

Ice hockey is a popular global sport with growing participation for boys and girls yet remains a high-risk sport for injury. While the evidence for some risk factors, such as bodychecking policy is well established, other risk factors such as player sex have been understudied. The objectives of this study were to examine factors associated with rates of game-related injury, game-related injury resulting in >7 days of time-loss, and practice-related injury in youth ice hockey.

MATERIALS AND METHODS

Safe2Play was a five-year prospective cohort study (2013-2018). All injuries were identified using validated injury surveillance methodology. Multilevel Poisson regression (adjusting for cluster by team and including multiple imputation of missing covariates) was used to estimate incidence rate ratios (IRRs) for player sex, age group, bodychecking policy, year of play, level of play, weight, previous injury within last 12 months, previous lifetime concussion history, and position.

RESULTS

A total of 4418 male and female ice hockey players (representing 6584 player-seasons) participating in under-13 (ages 11-12), under-15 (ages 13-14) and under-18 (ages 15-17) age groups were recruited. There were 1184 game-related and 182 practice-related injuries. Factors associated with game-related injury included female sex (IRR = 1.57; 95% CI: 1.18-2.08), previous injury (IRR = 1.46; 95% CI: 1.26-1.70) and lifetime concussion history (IRR = 1.41; 95% CI: 1.23-1.62). Goaltenders had a lower rate of injury (IRR = 0.54; 95% CI: 0.40-0.72) relative to forwards, as did players exposed to policy disallowing bodychecking in games (IRR = 0.44; 95% CI: 0.35-0.55). Female sex (IRR = 1.90; 95% CI: 1.10-3.28) and lifetime concussion history were also significantly associated with practice-related injury (IRR = 1.53; 95% CI: 1.08-2.18).

CONCLUSIONS

Based on data from a large 5-year Canadian youth ice hockey longitudinal cohort, several factors associated with injury were identified. Future injury prevention strategies should consider age, sex, previous concussion and injury history, and body checking leagues. Future research in female youth ice hockey including female-only leagues should be a priority to inform prevention strategies in this understudied population.

An initial assessment of an opinion leader-informed intervention to improve concussion-related outcomes among middle school parents: a randomized controlled trial

INTRODUCTION

There is a need for evidence-based prevention programming that can reduce head impacts and increase reporting and disclosure of concussion. This study assessed an intervention to decrease concussion risk and improve concussion management through improving concussion-related knowledge, attitudes, intentions, and self-efficacy among parents in the middle school (MS) sport setting.

PATIENTS AND METHODS

This randomized controlled trial (NCT04841473) examined parents of MS-aged children. Participants were randomized into one of two study arms: (1) CDC, which completed an education training module that compiled concussion education from the Centers for Disease Control and Prevention (CDC); and (2) TRAIN + CDC, which completed the CDC training module and an additional TRAIN educational module that provided strategies (originating from the Popular Opinion Leader framework) on communicating such information with one's personal peer networks and children. Validated measures of concussion-related knowledge, attitudes, intentions, and self-efficacy were collected before completing the training modules and one week following completion. Linear mixed model analyses examined differences in outcomes between study arms.

RESULTS

Overall, 103 parents completed the training modules and had valid pre- and post-intervention data (TRAIN + CDC n = 49; CDC n = 54). Analyses found that the study arms did not differ in the change scores from pre- to post-intervention across concussion-related outcomes. However, scores from pre- to post-intervention improved across both study arms for knowledge metrics, such as 'Concussions are less likely to happen when athletes play by the rules of the sport' (p < 0.001), and self-efficacy metrics, such as feeling confident in one's knowledge and recognition of concussion symptoms (p < 0.001 and p = 0.001, respectively).

CONCLUSIONS

Although study arms did not differ in change scores from pre- to post-intervention, beneficial increases were nonetheless found across both knowledge and self-efficacy. Additional research is needed to further examine the beneficial manners in which concussion education can be best delivered and the most effective.

Comparing the immediate effects of different neural mobilization exercises on hamstring flexibility in recreational soccer players

Background

Hamstring strain injuries remain a challenge for both athletes and clinicians given the high incidence rate, slow healing, and persistent symptoms. Increased tension in the neural structures is a known causative factor for hamstring tightness for which neural mobilization has emerged as a significant adjunct to routine stretching techniques.

Objective

To compare the short-term effects of neural sliding and neural tensioning on hamstring length in male recreational soccer players with hamstring tightness.

Methods

Sixty-two participants between ages 18 and 30 years were randomly assigned to one of the two groups viz. neural sliding or neural tensioning. Participants in either group performed the given stretching protocol in three sets. The Active Knee Extension Test (AKET) and Sit and Reach Test (SRT) were recorded before intervention, immediately after intervention, and after 60 min. between- and within group-analysis was done using analysis of variance.

Results

Between-group analysis showed that neural tensioning was more effective than neural sliding in improving hamstring length on both measures, however this difference was negligible. Within-group analysis demonstrated that the mean post-test scores on the AKET test and SRT were significantly greater than the pre-test scores in both groups (p < 0 . 05 ). A reduction in the post-test scores was observed after 60 min, irrespective of the type of stretching (p < 0 . 05 ).

Conclusion

There was no difference in short-term effects of neural sliding or neural tensioning on hamstring flexibility in male recreational soccer players. Both groups showed improved flexibility immediately after the intervention with reduction in the effect after 60 min.

Co-creation of injury prevention measures for competitive adolescent distance runners: knowledge, behavior, and needs of athletes and coaches enrolled on England Athletics' Youth Talent Programme

This study assessed the knowledge, behavior, and needs of competitive adolescent (16-18 years) distance runners and distance running coaches enrolled as part of England Athletics' Youth Talent Programme in relation to the prevention of running-related injury (RRI). Two online surveys were developed and distributed to the distance runners (survey one) and coaches (survey two). Both surveys included sections related to: (1) current knowledge; (2) current behavior; (3) need and support for RRI prevention measures; and (4) possible content and form of RRI prevention measures. A total of 39 distance runners (36% of total possible sample) completed survey 1, and 29 coaches (32% of total possible sample) completed survey 2. Key findings included that the majority of distance runners and coaches: (1) agreed that it is 'very important' to try to prevent RRI; (2) are currently implementing something in practice (e.g., strength training) to prevent RRI; and (3) view the creation of RRI prevention measures as an important initiative. Differences between distance runners and coaches were identified in relation to their understanding of the most common causes of RRI. Interestingly, distance runners identified a modifiable cause of RRI (i.e., too much training) as the most common cause of RRI, while coaches selected a non-modifiable cause of RRI (i.e., growth and maturation). These key findings were supplemented by competitive adolescent runners and distance running coaches detailing their delivery preferences for such RRI prevention measures. Results from this study will help inform subsequent steps of the larger co-creation process, with an emphasis on developing multifaceted and context-specific RRI prevention measures that are deemed to be feasible and acceptable for real-world implementation.

Three-dimensional sectional measurement approach for serial volume changes in shoulder muscles after arthroscopic rotator cuff repair

Purpose

This study assessed the serial volume changes in multiple shoulder muscles simultaneously following arthroscopic rotator cuff repair (ARCR) by a three-dimensional (3D) modeling-based sectional measurement. These volume changes were correlated with background preoperative factors.

Methods

Four consecutive magnetic resonance imaging scans (preoperatively and postoperatively at 3, 6, and 12 months) of 33 shoulders from 31 patients who underwent arthroscopic rotator cuff repair were examined. We focused on the sectional volume differences of the supraspinatus, infraspinatus, teres minor, and subscapularis between preoperatively and 3 months postoperatively (Dif.pre.3mo) and between 3 and 12 months postoperatively (Dif.3.12mo). The correlation between volume differences and clinical/demographic parameters was determined by a multivariate analysis.

Results

No statistically significant differences were observed for most serial changes in the shoulder muscle volumes. The tear-site muscles (supraspinatus and infraspinatus) showed similar tendencies for volume changes, whereas the non-tear-site muscles (teres minor and subscapularis) differed. A negative correlation was observed between Dif.pre.3mo and Dif.3.12mo for the supraspinatus, infraspinatus, and teres minor. These perioperative volume differences might correlate with tear size and symptom duration in the supraspinatus, as well as with a history of steroid injections and work and sports activity levels in the infraspinatus and teres minor.

Conclusion

The serial volume changes in multiple shoulder muscles after ARCR measured using our 3D sectional approach exhibited different tendencies and clinical implications depending on the primary and non-primary site of tears. Our method may serve as a potential indicator to facilitate muscle recovery and prevent the progression of postoperative muscle atrophy.

Jump performance and movement quality in 7- to 15-year-old competitive alpine skiers: a cross-sectional study

INTRODUCTION

Injury rates in competitive alpine skiing are high. With current methods, identifying people at risk is expensive and thus often not feasible at the youth level. The aims of this study were (1) to describe the jump performance and movement quality of youth competitive alpine skiers according to age and sex, (2) to compare the jump distance among skiers of different sexes and movement quality grades, and (3) to assess the inter-rater grading reliability of the qualitative visual movement quality classification of such jumps and the agreement between live and video-based post-exercise grading.

MATERIALS AND METHODS

This cross-sectional study is based on an anonymized dataset of 301 7- to 15-year-old competitive alpine skiers. The skiers performed two-legged forward triple jumps, whereby the jump distance was measured, and grades were assigned by experienced raters from the frontal and sagittal perspectives depending on the execution quality of the jumps. Furthermore, jumps were filmed and ultimately rated post-exercise. Differences in jump distance between various groups were assessed by multivariate analyses of variance (MANOVAs). Reliability was determined using Kendall's coefficient of concordance.

RESULTS

The jump distance was significantly greater in U16 skiers than in U11 skiers of both sexes and in skiers with good execution quality than in those with reduced or poor execution quality. Overall, jump distance in U16 skiers significantly differed between female (5.37 m with 95% CI [5.21, 5.53]) and male skiers (5.90 m with 95%CI [5.69, 6.10]). Slightly better inter-rater grading reliability was observed for video-based post-exercise (strong agreement) ratings than for live ratings (moderate agreement).

CONCLUSION

In competitive alpine skiers aged 7 to 15 years, jump performance increases with age, and around puberty, sex differences start to manifest. Our results highlight the importance of evaluating both jump distance and movement quality in youth skiers. To improve test-retest reliability, however, a video-based post-exercise evaluation is recommended.

A systematic review and network meta-analysis on the effectiveness of exercise-based interventions for reducing the injury incidence in youth team-sport players. Part 2: an analysis by movement patterns

The objectives of this network meta-analysis were: (a) to estimate and compare the pooled effects of some injury prevention programs (IPPs) whose exercise-based components were categorized using a movement pattern-specific taxonomy on reducing overall and some specific body regions (lower extremity, thigh, knee, and ankle) injury incidences in youth team sport athletes and (b) to explore the individual effects of these components on the injury incidence rates (IIRs) previously mentioned. Searches were performed in PubMed, Web of Science, SPORTDiscus, and Cochrane Library. Eligible criteria were: exercise-based interventions comprised of exercises involving athletic motor skill competencies and evaluated against a control group, overall IIRs were reported, and youth (≤19 years old) team sport players. For the current analysis, a taxonomy based on movement patterns was employed for exercise component identification (upper body pushing and pulling; lower body concentric and eccentric; core; mechanics; acceleration; and lower body stability). Pooled effects were calculated by frequentist random effects pairwise and network meta-analyses. Nineteen studies were included. Most of the IPPs exhibit risk reduction when compared to their control groups on overall, lower extremity, and ankle injuries. Interventions comprised of lower body concentric and eccentric, core, mechanics, and lower body stability exercises were the most effective measures for reducing these injuries. None of the IPPs demonstrated to be effective for reducing thigh injuries, and contradictory results were found for knee injuries. Individual analysis at component level revealed that the lower body (bilateral and unilateral, concentric, and eccentric) component was the only one associated with a significant reduction on overall injuries. Indirect evidence suggests that interventions incorporating lower body concentric and eccentric, core, mechanics, and lower body stability exercises might be the most effective for reducing overall, lower extremity, and ankle injuries in youth team sports.

Catastrophic injuries and exertional medical events in lacrosse among youth, high school and collegiate athletes: longitudinal surveillance over four decades (1982-2020)

OBJECTIVE

To determine the incidence rates (IRs) of catastrophic injuries and exertional medical events in lacrosse athletes.

METHODS

Catastrophic injuries and exertional medical events in lacrosse in the US among youth or amateur, high school and college athletes were analysed from the National Center for Catastrophic Sport Injury Research (NCCSIR) database from 1982/83 to 2019/20. Frequencies, IRs per 100,000 athlete-seasons (AS) with 95% confidence intervals (CIs), and incidence rate ratios (IRRs) with 95% CIs were calculated. Participation data were gathered from the National Federation of State High School Associations (NFHS), National Collegiate Athletic Association (NCAA) and USA Lacrosse.

RESULTS

Sixty-nine catastrophic events (16 youth or amateur, 36 high school and 17 college; 84% male) occurred in US lacrosse from 7/1/1982 to 6/30/2020. Thirty-six percent of all incidents were fatal. The overall IR was 0.5 per 100,000 AS (95% CI: 0.4-0.7). There were 15 cases of non-traumatic sudden cardiac arrests (SCAs) and 15 incidents of commotio cordis. Fatality rates from SCA and commotio cordis decreased 95% (IRR = 0.05; 95% CI: 0, 0.2) from 1982/83-2006/07 to 2007/08-2019/20. Incidence rates were higher for collegiate versus high school 1982/83-2019/20 (IRR = 3.2; 95% CI: 1.8, 5.7) and collegiate versus youth 2005/06-2019/20 (IRR = 8.0; 95% CI: 3.0, 21.4) level. Contact with a stick or ball (41%) and contact with another player (20%) were the primary mechanisms of injury.

CONCLUSIONS

The incidence of catastrophic events during lacrosse was higher among collegiate than high school or youth athletes. SCA from an underlying cardiac condition or from commotio cordis was the most common catastrophic event. Fatality rates from catastrophic injuries have declined significantly over the study period, perhaps driven by protective measures adopted by lacrosse governing bodies.

The current status of various preclinical therapeutic approaches for tendon repair

Tendons are fibroblastic structures that link muscle and bone. There are two kinds of tendon injuries, including acute and chronic. Each form of injury or deterioration can result in significant pain and loss of tendon function. The recovery of tendon damage is a complex and time-consuming recovery process. Depending on the anatomical location of the tendon tissue, the clinical outcomes are not the same. The healing of the wound process is divided into three stages that overlap: inflammation, proliferation, and tissue remodeling. Furthermore, the curing tendon has a high re-tear rate. Faced with the challenges, tendon injury management is still a clinical issue that must be resolved as soon as possible. Several newer directions and breakthroughs in tendon recovery have emerged in recent years. This article describes tendon injury and summarizes recent advances in tendon recovery, along with stem cell therapy, gene therapy, Platelet-rich plasma remedy, growth factors, drug treatment, and tissue engineering. Despite the recent fast-growing research in tendon recovery treatment, still, none of them translated to the clinical setting. This review provides a detailed overview of tendon injuries and potential preclinical approaches for treating tendon injuries.

Mesenchymal stem cells in orthopaedics: A systematic review of applications to practice

Background

Mesenchymal stem cells (MSCs) have alluring interest for clinical use in orthopaedics based on their therapeutic potential through directed pluripotent differentiation. While many studies and reviews have discussed the importance of this approach, few have reduced it to practice using reproducible criteria. This study was designed to systematically review and synthesize current evidence regarding clinical use of clearly defined MSCs in orthopaedics.

Methods

Studies of any level of evidence and sample size, regardless of MSC source, orthopaedic pathology, and patient population, were reviewed. In vitro and animal studies, and articles written in a language other than English, were excluded. Studies were then screened for final inclusion based on documented MSC verification using testing of the therapeutic cellular population for at least one of the following phenotypic markers: CD 73, CD 90, and CD 105. In addition, therapeutic cellular populations could not have higher percentages of CD34, CD45, CD14, HLA-DR, CD11b, or CD19 markers compared to the aforementioned markers. From each studies' results, sample size, procedural methods, radiographic outcomes, clinical outcomes, patient-report outcomes (PROs), and adverse events were tabulated.

Results

Overall, 43 studies were included. Twenty-three studies (53.5 %) derived their MSCs from iliac crest bone marrow while 12 (27.9 %) studied adipose-derived MSCs. Included studies explored MSC use in Osteoarthritis, Cartilage Defects, Osteonecrosis, Bone Defects and Nonunions, Spine, and Other. MSC use in all pathologies led to improvement of studied radiographic, clinical, and patient-reported outcomes.

Conclusions

Mesenchymal stem cells have proven to have successful and safe uses in multiple orthopaedic applications, including treating chondral defects, osteoarthritis, and osteonecrosis. A stringent and reproducible process for evaluating obtained human stem cells using CD markers for clinical use is necessary to both evaluate previous studies and continue to evaluate for future uses.

Level of evidence

Level V.

The major league baseball pitch clock: First year analysis of pitcher injuries

Introduction

Recently, star pitchers in Major League Baseball (MLB) have faced devastating elbow injuries, causing some to question whether implementation of the MLB pitch clock during the 2023 season has led to a higher rate of elbow injuries among pitchers. This study aims to determine if implementation of the MLB pitch clock in the 2023 MLB season affected the injury rate in pitchers.

Methods

Injury data was collected for the 2021, 2022, and 2023 MLB seasons using the fangraphs.com injury database. Incidence rate ratio was calculated to compare the injury rate for the 2023 season to the 2021 and 2022 seasons. A z-test for proportions was used to determine significance levels.

Results

The 2023 season showed a decrease in the rate of the total number of injuries when compared to the 2021 (P = 0.01) and 2022 (P = 0.02) seasons. There was no statistical difference in the rate of Tommy John Surgery, Flexor Tendon Injuries, or other cause elbow injuries.

Conclusion

Following implementation of the MLB pitch clock during the 2023 season, the total number of injuries decreased, but there was no change in the rate of elbow injuries in pitchers compared with the 2021 and 2022 MLB seasons. Future studies are needed to determine if the pitch clock has a longitudinal effect on injuries.

Risk factors for running-related injuries: An umbrella systematic review

PURPOSE

This umbrella systematic review (SR) of SRs and meta-analysis seeks to comprehensively synthesize existing literature to identify and consolidate the diverse range of risk factors contributing to running-related injuries (RRIs).

METHODS

Systematic searches were conducted on June 28, 2023, across Web of Science, SPORTDiscus, Scopus, PubMed, and Cochrane Library. We included SRs, whether accompanied by meta-analyses or not, that focused on investigating risk factors for RRIs within observational studies. The methodological quality of the SRs was evaluated using the Assessing the Methodological Quality of Systematic Reviews II. To assess the extent of overlap across reviews, the corrected covered area metric was calculated.

RESULTS

From 1509 records retrieved, 13 SRs were included. The degree of overlap between SRs was low (4%), and quality varied from critically low (n = 8) to low (n = 5). Two hundred seven outcomes assessed in 148 primary studies were identified as being associated with the occurrence of RRIs. The effect sizes of the associations for which risk measures were reported (n = 131) were classified as large (n = 30, 23%), medium (n = 38, 29%), small (n = 48, 37%) or no effect (n = 15, 11%). Running/training characteristics, health and lifestyle factors, along with morphological and biomechanical aspects, exhibit large effect sizes in increasing the risk for RRIs.

CONCLUSION

Drawing from the outcomes of the low-quality SRs and associations with large effect sizes, our findings indicate that running/training characteristics and health and lifestyle factors, as well as morphological and biomechanical aspects, are all implicated in elevating the risk of RRIs, emphasizing the multifactorial basis of injury incidence in running. Given the low quality and heterogeneity of SR, individual findings warrant cautious interpretation.

An injectable self-healing alginate hydrogel with desirable mechanical and degradation properties for enhancing osteochondral regeneration

Articular cartilage and subchondral bone defects have always been problematic because the osteochondral tissue plays a crucial role in the movement of the body and does not recover spontaneously. Here, an injectable hydrogel composed of oxidized sodium alginate/gelatin/chondroitin sulfate (OSAGC) was designed for the minimally invasive treatment and promotion of osteochondral regeneration. The OSAGC hydrogel had a double network based on dynamic covalent bonds, demonstrating commendable injectability and self-healing properties. Chondroitin sulfate was organically bound to the hydrogel network, retaining its own activity and gradually releasing during the degradation process as well as improving mechanical properties. The compressive strength could be increased up to 3 MPa by regulating the concentration of chondroitin sulphate and the oxidation level, and this mechanical stimulation could help repair injured tissue. The OSAGC hydrogel had a favourable affinity to articular cartilage and was able to release active ingredients in a sustained manner over 3 months. The OSAGC showed no cytotoxic effects. Results from animal studies demonstrated its capacity to regenerate new bone tissue in four weeks and new cartilage tissue in twelve weeks. The OSAGC hydrogel represented a promising approach to simplify bone surgery and repair damaged osteochondral tissue.

Elevated fluid and glycosaminoglycan content in the Achilles tendon contribute to higher intratendinous pressures: Implications for Achilles tendinopathy

BACKGROUND

Tendinopathy alters the compositional properties of the Achilles tendon by increasing fluid and glycosaminoglycan content. It has been speculated that these changes may affect intratendinous pressure, but the extent of this relationship remains unclear. Therefore, we aimed to investigate the impact of elevated fluid and glycosaminoglycan content on Achilles tendon intratendinous pressure and to determine whether hyaluronidase (HYAL) therapy can intervene in this potential relationship.

METHODS

Twenty paired fresh-frozen cadaveric Achilles tendons were mounted in a tensile-testing machine and loaded up to 5% strain. Intratendinous resting (at 0% strain) and dynamic pressure (at 5% strain) were assessed using the microcapillary infusion technique. First, intratendinous pressure was measured under native conditions before and after infusion of 2 mL physiological saline. Next, 80 mg of glycosaminoglycans were administered bilaterally to the paired tendons. The right tendons were additionally treated with 1500 units of HYAL. Finally, both groups were retested, and the glycosaminoglycan content was analyzed.

RESULTS

It was found that both elevated fluid and glycosaminoglycan content resulted in higher intratendinous resting and dynamic pressures (p < 0.001). HYAL treatment induced a 2.3-fold reduction in glycosaminoglycan content (p = 0.002) and restored intratendinous pressures.

CONCLUSION

The results of this study demonstrated that elevated fluid and glycosaminoglycan content in Achilles tendinopathy contribute to increased intratendinous resting and dynamic pressures, which can be explained by the associated increased volume and reduced permeability of the tendon matrix, respectively. HYAL degrades glycosaminoglycans sufficiently to lower intratendinous pressures and may, therefore, serve as a promising treatment.

Critical Examination of Methods to Determine Tibiofemoral Kinematics and Tibial Contact Kinematics Based on Analysis of Fluoroscopic Images

Goals of knee replacement surgery are to restore function and maximize implant longevity. To determine how well these goals are satisfied, tibial femoral kinematics and tibial contact kinematics are of interest. Tibiofemoral kinematics, which characterize function, is movement between the tibia and femur whereas tibial contact kinematics, which is relevant to implant wear, is movement of the location of contact by the femoral implant on the tibial articular surface. The purposes of this review article are to describe and critique relevant methods to guide correct implementation. For tibiofemoral kinematics, methods are categorized as those which determine (1) relative planar motions and (2) relative three-dimensional (3D) motions. Planar motions are determined by first finding anterior-posterior (A-P) positions of each femoral condyle relative to the tibia and tracking these positions during flexion. Of the lowest point (LP) and flexion facet center (FFC) methods, which are common, the lowest point method is preferred and the reasoning is explained. 3D motions are determined using the joint coordinate system (JCS) of Grood and Suntay. Previous applications of this JCS have resulted in motions which are largely in error due to "kinematic crosstalk." Requirements for minimizing kinematic crosstalk are outlined followed by an example, which demonstrates the method for identifying a JCS that minimizes kinematic crosstalk. Although kinematic crosstalk can be minimized, the need for a JCS to determine 3D motions is questionable based on anatomical constraints, which limit varus-valgus rotation and compression-distraction translation. Methods for analyzing tibial contact kinematics are summarized and validation of methods discussed.

Conservative treatment versus surgical reconstruction for ACL rupture: A systemic review

Background

Anterior cruciate ligament (ACL) rupture is a prevalent sports injury with rising rates attributed to increased population participation in sports activities. ACL rupture can lead to severe knee complications including cartilage damage, torn meniscus, and osteoarthritis. Current treatment options include conservative measures and surgical interventions. However, debates persist regarding the optimal approach.

Purpose

This analysis intended to compare the function, knee stability, and incidence rate of secondary surgery between conservative and surgical treatments in ACL rupture patients.

Methods

A systematic search was performed via Embase, Ovid Medline, PubMed, Cochrane Library, Web of Science, and Google Scholar for reporting outcomes of conservative and surgical treatments after ACL rupture. The outcomes included patient-reported outcome measures (PROMs), knee stability, the need for secondary meniscal surgery, delayed ACL reconstruction surgery, and revision ACL reconstruction surgery. Outcomes were analyzed using mean differences or odd ratios (OR) with 95 % CIs.

Results

11 studies were included with 1516 patients. For PROMs, our evidence indicated no differences in KOOS Pain, KOOS Symptoms, KOOS Sport/Rec, KOOS ADL, and KOOS QOL. (all p > 0.05). for knee stability, pivot shift (OR, 0.14; p < 0.001), Lachman test (OR, 0.06; p < 0.001), and tibia translation (p < 0.001) were evaluated, and the available evidence favored surgical treatment over conservative treatment. For the incidence rate of any secondary surgery after the first diagnosis, the surgical group showed a lower rate of meniscal surgery with statistical significance (OR, 0.37; p < 0.001). The average rate of revision ACL reconstruction is 5.80 %, while the rate of delayed ACL reconstruction after conservative treatment is 18.51 %.

Conclusion

Currently, there is insufficient empirical evidence to advocate a systematic surgical reconstruction for any patient who tore his ACL. This review found no differences in function outcomes between conservative and surgical treatments. Regarding knee stability and secondary meniscal surgery, the results prefer the surgical treatments. The occurrence rate of revision and delayed ACL reconstruction are non-negligible factors that must be fully understood by both surgeons and patients before choosing a suitable treatment.

Optimal Implant Positioning Following Total Knee Arthroplasty Using Predictive Dynamic Simulation

In this paper, a novel method is proposed for the determination of the optimal subject-specific placement of knee implants based on predictive dynamic simulations of human movement following total knee arthroplasty (TKA). Two knee implant models are introduced. The first model is a comprehensive 12-degree-of-freedom (DoF) representation that incorporates volumetric contact between femoral and tibial implants, as well as patellofemoral contact. The second model employs a single-degree-of-freedom equivalent kinematic (SEK) approach for the knee joint. A cosimulation framework is proposed to leverage both knee models in our simulations. The knee model is calibrated and validated using patient-specific data, including knee kinematics and ground reaction forces. Additionally, quantitative indices are introduced to evaluate the optimality of implant positioning based on three criteria: balancing medial and lateral load distributions, ligament balancing, and varus/valgus alignment. The knee implant placement is optimized by minimizing the deviation of the indices from their user-defined desired values during predicted sit-to-stand motion. The method presented in this paper has the potential to enhance the results of knee arthroplasty and serve as a valuable instrument for surgeons when planning and performing this procedure.

Drilling the tibial tunnel in an arthroscopic popliteus bypass from the anteromedial tibial cortex decreases risk of popliteal vascular injury

Purpose

Drilling the tibial tunnel in tibiofibular-based posterolateral corner (PLC) reconstructions is usually performed with a starting point from Gerdy's tubercle. Drilling the tunnel starting from the anteromedial tibial cortex could reduce the risk of popliteal neurovascular (PNV) injury. The purpose of this study is to assess the distance on Magnetic Resonance Imaging Scans (MRI) of the PNV bundle and peroneal nerve (PN) to these two different tunnel trajectories.

Methods

A total of 87 MRI scans were assessed. The ideal exit point of the tibial tunnel in PLC reconstructions was marked. We added 10 mm from this point in a straight posterior and in an oblique trajectory, mimicking the two different tunnel trajectories and measured the distance to the PNV bundle and PN from these two points.

Results

The mean distance of the tip of the guide wire drilled with a trajectory from Gerdy's tubercle to the PNV bundle and the peroneal nerve was respectively 13.2 mm (SD = 3.96) and 17.7 mm (SD = 4.39). The mean distance of the tip of the guide wire drilled with a trajectory from the anteromedial tibial cortex to the PNV bundle and the PN was respectively 19.6 mm (SD = 4.19) and 12.2 mm (SD = 3.96).). Drilling in a trajectory from the anteromedial tibial cortex significantly increases the distance to the PNV bundle (p < 0.001).

Conclusion

Tibial tunnel drilling in a tibiofibular based PLC reconstruction from the anteromedial tibial cortex significantly increases the distance to the popliteal artery but with a decreased distance to the peroneal nerve.

Level of evidence

level IV.

Abnormal lateral meniscal signal in MRI after patellar dislocation does not indicate a meniscal tear: MR findings with surgical correlation

Background

Combined injuries observed with first-time lateral patellar dislocation (LPD) of the knee, particularly significant soft tissue injury, can inform surgical intervention criteria.

Purpose

The purpose of this study was to compare MRI findings in LPD to surgical correlation concerning meniscal pathology as a guide for surgical management.

Study design

Retrospective case series, Level of evidence, 4.

Methods

A retrospective review was conducted of 355 cases of patients with lateral patellar dislocation from 2012 to 2022. Imaging was reviewed by musculoskeletal radiologists blinded to surgical results for evidence of soft tissue injury, and associated arthroscopic data and operative reports were reviewed.

Results

Out of 44 cases of LPD in 42 patients who underwent MPFL reconstructive surgery, 27 (61%) cases had grade 2a or higher signal changes in the anterior horn of the lateral meniscus, of which 10 (23%) had grade 3 signal changes. There were zero cases of meniscal tear in these cases upon review of operative reports and arthroscopic images.

Conclusion

MRI findings of signal alterations in the lateral meniscus post-LPD may not indicate an actual tear. This could aid in surgical decision-making in primary LPD management.

Cartilage regeneration and long term survival in medial OA knee patients treated with HTO and OATS

Background

Osteoarthritis (OA) of the knee, in most instances primarily, affects medial compartment of knee. Combining Osteochondral Autologous Transfer System (OATS) with Medial Open-Wedge High Tibial Osteotomy (MOWHTO) may represent an integrated approach to sustaining long-term knee functionality in OA patients.

Materials and methods

From 2009 to 2016, combined OATS and MOWHTO was performed in 66 knees of 63 patients with medial compartment knee OA. Cartilage regeneration was assessed by 2nd look arthroscopy and Knee function was assessed by knee society scoring (KSS) pre-operatively and post-operatively. The survival rate of MOWHTO plus OATS was assessed. Failure is characterized by the need to convert into total knee replacement.

Results

The KSS knee score (from 48.3 to 90.4) and function score (from 42.6 to 88.7) showed a statistically significant improvement (p-value of <0.0001) at a mean follow-up period of 9.49 years. Second look arthroscopy done at the time of implant removal showed 100 % cartilage regeneration with even hyaline cartilage regeneration in 49 out of 57 knees assessed and partial regeneration in 8 knees. The Kaplan Meier survivorship analysis was 96.7 % at the mean 9.49 years after surgery. Only 2 patients needed TKA conversion in follow-up.

Conclusion

Combining OATs and valgus MOWHTO provides good option to successfully manage patients of OA and varus malalignment. This resulted in significant improvement in knee function, lowering pain intensity, good cartilage regeneration, and a high survivorship rate for 10 years postoperatively.

Skill building in freediving as an example of embodied culture

Skilled activity is a complex mix of automatized action, changed attention patterns, cognitive strategies and physiological adaptations developed within a community of practice. Drawing on physiological and ethnographic research on freediving, this article argues that skill acquisition demonstrates the variety of mechanisms that link biological and cultural processes to produce culturally shaped forms of embodiment. In particular, apneists alter phenotypic expression through patterned practices that canalize development, exaggerating the dive response, developing resistance to elevated carbon dioxide levels (hypercapnia) and accommodating hydrostatic pressure at depth. The community of divers provides technical advice and helps to orient individuals' motivations. Some biological processes are phenomenologically accessible, but others are sub-aware and must be accessed indirectly through behaviour or altered interactions with the environment. The close analysis of embodied skills like freediving illustrates how phenotypic plasticity is inflected by culturally patterned behaviours. Divers do developmental work on bodily traits like the dive response to achieve more dramatic performance, even if they cannot directly control all elements of the neurological and physiological responses. The example of expert freediving illustrates the imbrication of biology and culture in embodiment. This article is part of the theme issue 'Minds in movement: embodied cognition in the age of artificial intelligence'.

Bioceramic-mediated chondrocyte hypertrophy promotes calcified cartilage formation for rabbit osteochondral defect repair

Osteochondral tissue is a highly specialized and complex tissue composed of articular cartilage and subchondral bone that are separated by a calcified cartilage interface. Multilayered or gradient scaffolds, often in conjunction with stem cells and growth factors, have been developed to mimic the respective layers for osteochondral defect repair. In this study, we designed a hyaline cartilage-hypertrophic cartilage bilayer graft (RGD/RGDW) with chondrocytes. Previously, we demonstrated that RGD peptide-modified chondroitin sulfate cryogel (RGD group) is chondro-conductive and capable of hyaline cartilage formation. Here, we incorporated whitlockite (WH), a Mg2+-containing calcium phosphate, into RGD cryogel (RGDW group) to induce chondrocyte hypertrophy and form collagen X-rich hypertrophic cartilage. This is the first study to use WH to produce hypertrophic cartilage. Chondrocytes-laden RGDW cryogel exhibited significantly upregulated expression of hypertrophy markers in vitro and formed ectopic hypertrophic cartilage in vivo, which mineralized into calcified cartilage in bone microenvironment. Subsequently, RGD cryogel and RGDW cryogel were combined into bilayer (RGD/RGDW group) and implanted into rabbit osteochondral defect, where RGD layer supports hyaline cartilage regeneration and bioceramic-containing RGDW layer promotes calcified cartilage formation. While the RGD group (monolayer) formed hyaline-like neotissue that extends into the subchondral bone, the RGD/RGDW group (bilayer) regenerated hyaline cartilage tissue confined to its respective layer and promoted osseointegration for integrative defect repair.

Exosomes derived from tendon stem/progenitor cells enhance tendon-bone interface healing after rotator cuff repair in a rat model

The rate of retear after surgical repair remains high. Mesenchymal stem cells (MSCs) have been extensively employed in regenerative medicine for several decades. However, safety and ethical concerns constrain their clinical application. Tendon Stem/Progenitor Cells (TSPCs)-derived exosomes have emerged as promising cell-free therapeutic agents. Therefore, urgent studies are needed to investigate whether TSPC-Exos could enhance tendon-bone healing and elucidate the underlying mechanisms. In this study, TSPC-Exos were found to promote the proliferation, migration, and expression of fibrogenesis markers in BMSCs. Furthermore, TSPC-Exos demonstrated an ability to suppress the polarization of M1 macrophages while promoting M2 macrophage polarization. In a rat model of rotator cuff repair, TSPC-Exos modulated inflammation and improved the histological structure of the tendon-bone interface, the biomechanical properties of the repaired tendon, and the function of the joint. Mechanistically, TSPC-Exos exhibited high expression of miR-21a-5p, which regulated the expression of PDCD4. The PDCD4/AKT/mTOR axis was implicated in the therapeutic effects of TSPC-Exos on proliferation, migration, and fibrogenesis in BMSCs. This study introduces a novel approach utilizing TSPC-Exos therapy as a promising strategy for cell-free therapies, potentially benefiting patients with rotator cuff tear in the future.

Collagen degradation assessment with an in vitro rotator cuff tendinopathy model using multiparametric ultrashort-TE magnetization transfer (UTE-MT) imaging

PURPOSE

This study aims to assess ultrashort-TE magnetization transfer (UTE-MT) imaging of collagen degradation using an in vitro model of rotator cuff tendinopathy.

METHODS

Thirty-six supraspinatus tendon specimens were divided into three groups and treated with 600 U collagenase (Group 1), 150 U collagenase (Group 2), and phosphate buffer saline (Group 3). UTE-MT imaging was performed to assess changes in macromolecular fraction (MMF), macromolecule transverse relaxation time (T2m), water longitudinal relaxation rate constant (R1m), the magnetization exchange rate from the macromolecular to water pool (Rm0 w) and from water to the macromolecular pool (Rm0 m), and magnetization transfer ratio (MTR) at baseline and following digestion and their differences between groups. Biochemical and histological studies were conducted to determine the extent of collagen degradation. Correlation analyses were performed with MMF, T2m, R1m, Rm0 w, Rm0 m, and MTR, respectively. Univariate and multivariate linear regression analyses were performed to evaluate combinations of UTE-MT parameters to predict collagen degradation.

RESULTS

MMF, T2m, R1m, Rm0 m, and MTR decreased after digestion. MMF (r = -0.842, p < 0.001), MTR (r = -0.78, p < 0.001), and Rm0 m (r = -0.662, p < 0.001) were strongly negatively correlated with collagen degradation. The linear regression model of differences in MMF and Rm0 m before and after digestion explained 68.9% of collagen degradation variation in the tendon. The model of postdigestion in MMF and T2m and the model of MTR explained 54.2% and 52.3% of collagen degradation variation, respectively.

CONCLUSION

This study highlighted the potential of UTE-MT parameters for evaluation of supraspinatus tendinopathy.

Considerations for revision anterior cruciate ligament reconstruction: A review of the current literature

Background

Failure rates among primary Anterior cruciate ligament reconstruction range from 3.2 to 11.1 %. Recently, there has been increased focus on surgical and anatomic considerations which predispose patients to failure, including excessive posterior tibial slope (PTS), unaddressed high-grade pivot shift, and improper tunnel placement.

Methods

The purpose of this review was to provide a current summary and analysis of the literature regarding patient-related and technical factors surrounding revision ACLR, rehabilitation considerations, overall outcomes, and return to sport (RTS) for patients who undergo revision ACLR.

Results

In revision ACLR patients, those receiving autografts are 2.78 times less likely to experience a re-rupture compared to patients who receive allografts. Additionally, individuals with properly positioned tunnels and removable implants are considered strong candidates for one-stage revision procedures. Conversely, cases involving primary tunnel widening of approximately 15 mm are typically indicative of two-stage revision ACLR. These findings underscore the importance of graft selection and surgical approach in optimizing outcomes for patients undergoing revision ACLR.

Conclusion

Given the high rates of revision surgery in young, active patients who return to pivoting sports, the literature recommends strong consideration of a combined ACLR + anterolateral ligament (ALL) or lateral extra-articular tenodesis (LET) procedure in this population. Unrecognized posterolateral corner (PLC) injury is a common cause of ACLR failure and current literature suggests concurrent operative management of high-grade PLC injuries. Excessive PTS has been identified as an independent risk factor for ACL graft failure. Consider revision ACLR with combined slope-reducing tibial osteotomy in cases of posterior tibial slope greater than 12°.

Physiotherapy practices in the clinical assessment of lateral elbow tendinopathy: An international survey

BACKGROUND AND PURPOSE

Understanding physiotherapy practices is important to identify variations from empirical evidence and highlight requirements for training. This survey explored international physiotherapy practices for assessment of lateral elbow tendinopathy (LET).

METHODS

Two hundred ninety-nine surveyed physiotherapists from eight member countries of the International Federation of Manual and Orthopaedic Physical Therapists completed the survey. Respondents rated their frequency of use (never, rarely, sometimes, often, and always) for items related to: patient history; diagnostic tests; grip and upper limb strength; cervical and neurological assessment; and medical imaging. To establish practices, the five response categories were dichotomised into routine practice (often, always) and not-routine practice (sometimes, rarely, never). A response rate of ≥70% for each dichotomy was used to determine whether an assessment item was deemed routine practice or not, with items not meeting either criterion considered neither routine nor not-routine practice.

RESULTS

Most respondents were from United States (63%). The 'chair pick up test', 'cervical special tests', and 'plain radiograph' met our criteria for not routine practice (i.e., 70%, 72%, and 71%, respectively). All other assessment items did not meet the criteria to be considered routine or not-routine practice.

CONCLUSION

The chair pick-up test, cervical spine special tests (e.g., Spurling's test), and plain radiography appear to not be routinely used in the assessment of LET. The finding that no assessment technique met the criteria for routine use may imply that physiotherapists adopt a nuanced approach to selecting clinical assessment items as opposed to routinely applying tests.

In Vitro Assessment of Knee Joint Biomechanics Using a Virtual Anterior Cruciate Ligament Reconstruction

Understanding the biomechanical impact of injuries and reconstruction of the anterior cruciate ligament (ACL) is vital for improving surgical treatments that restore normal knee function. The purpose of this study was to develop a technique that enables parametric analysis of the effect of the ACL reconstruction (ACLR) in cadaver knees, by replacing its contributions with that of a specimen-specific virtual ACLR that can be enabled, disabled, or modified. Twelve ACLR reconstructed knees were mounted onto a motion simulator. In situ ACLR graft forces were measured using superposition, and these data were used to design specimen-specific virtual ACLRs that would yield the same ligament force-elongation behaviors. Tests were then repeated using the virtual ACLR in place of the real ACLR and following that in ACL deficient knee by disabling the virtual ACLR. In comparison to the ACL deficient state, the virtual ACLRs were able to restore knee stability to the same extent as real ACLRs. The average differences between the anterior tibial translation (ATT) of the virtual ACLR versus the real ACLR were +1.6 ± 0.9 mm (p = 0.4), +2.1 ± 0.4 mm (p = 0.4), and +1.0 ± 0.9 mm (p = 0.4) during Anterior drawer, Lachman and Pivot-shift tests, respectively, which is small in comparison to the full ATT range of motion (ROM) of these knees. Therefore, we conclude that a virtual ACLR can be used in place of real ACLR during biomechanical testing of cadaveric knees. This capability opens the door for future studies that can leverage parameterization of the ACLR for surgical design optimization.

Melatonin enhances therapeutic outcomes of adipose tissue-derived mesenchymal stem cell therapy in rat osteoarthritis by reducing TNF-α and IL-1β-induced injuries

Although adipose tissue-derived mesenchymal stem cell (ADSC) transplantation has been effectively used to treat osteoarthritis (OA), the low cell survival rate induced by the inflammatory and oxidative stress, severely affects the therapeutic efficiency of ADSC transplantation in OA. This study was designed to evaluate whether melatonin pretreatment could improve ADSC survival and its therapeutic efficacy in OA. The papain-induced OA rats were pretreated with melatonin via intra-articular injection and then intra-articular injected with indocyanine green (ICG)-labeled ADSCs (3 × 106/rat). Afterward, ADSC retention was evaluated by NIR-II fluorescence imaging. The tibia and synovial fluid were collected for histopathological examination and ELISA assay, respectively. To confirm the anti-inflammatory effect of melatonin, a TNF-α and IL-1β-induced cell model was used to evaluate the protective effects of melatonin on ADSC viability, cell apoptosis, and migration. Our results showed that melatonin pretreatment enhanced ADSC survival and improved the therapeutic effects of ADSC transplantation on cartilage repair, and anti-inflammation by reducing TNF-α, IL-6, IL-1β, and IL-12 in vivo. In particular, we also found that melatonin promoted ADSC viability and migration, and reduced cell apoptosis in vitro. In conclusion, this study supports that melatonin pretreatment can effectively improve ADSC survival and therapeutic efficiency in OA by reducing inflammatory injuries, which provides a novel strategy for enhancing ADSC therapy.

Fostering tissue engineering and regenerative medicine to treat musculoskeletal disorders in bone and muscle

The musculoskeletal system, which is vital for movement, support, and protection, can be impaired by disorders such as osteoporosis, osteoarthritis, and muscular dystrophy. This review focuses on the advances in tissue engineering and regenerative medicine, specifically aimed at alleviating these disorders. It explores the roles of cell therapy, particularly Mesenchymal Stem Cells (MSCs) and Adipose-Derived Stem Cells (ADSCs), biomaterials, and biomolecules/external stimulations in fostering bone and muscle regeneration. The current research underscores the potential of MSCs and ADSCs despite the persistent challenges of cell scarcity, inconsistent outcomes, and safety concerns. Moreover, integrating exogenous materials such as scaffolds and external stimuli like electrical stimulation and growth factors shows promise in enhancing musculoskeletal regeneration. This review emphasizes the need for comprehensive studies and adopting innovative techniques together to refine and advance these multi-therapeutic strategies, ultimately benefiting patients with musculoskeletal disorders.

Effects of a supraphysiological dose of testosterone cypionate on salivary gland function in adult male Wistar rats

The abusive use of anabolic androgenic steroids has become a serious health problem worldwide, but its effects on oral health are still poorly understood. Therefore, the objective of this study was to evaluate the effects of a supraphysiological dose of testosterone cypionate (TC) on salivary biochemical, histomorphology, immunohistochemistry, and redox state parameters of parotid and submandibular glands. Twenty male Wistar rats, 12 weeks old, were divided into two groups (n=10/group): a control group and TC group, which received a dose of 20 mg/kg, once a week, for 6 weeks. Post treatment, the saliva and glands were collected. A supraphysiological dose of TC increased plasma and salivary testosterone concentrations. Although TC did not alter salivary flow, pH, and buffering capacity, the treatment increased the salivary secretion of total protein and reduced amylase, calcium, phosphate, and potassium. TC reduced the connective tissue area in the parotid gland and acinar area of the submandibular gland, while increasing the granular convoluted tubule area in the submandibular gland. Proliferating cell nuclear antigen was higher in the acinar cells of the submandibular glands from the TC group. Moreover, TC increased concentrations of total oxidant capacity and damaged lipids in both salivary glands, while total antioxidant activity and uric acid were lower in the submandibular gland, and reduced glutathione was higher in both glands. Superoxide dismutase, catalase, and glutathione peroxidase activities were higher in the parotid gland, while only glutathione peroxidase activity was lower in the submandibular gland of the TC group. In conclusion, TC abuse may be a potential factor for dysfunction of the parotid and submandibular glands, becoming a risk factor for the oral and systemic health of users.

Establishment of a selective puncture method of the temporomandibular joint targeting the superior and inferior joint spaces using a human cadaver under the guidance of an ultrasound device

OBJECTIVE

To investigate an ultrasound-guided selective puncture method for the temporomandibular joint (TMJ), targeting superior (SJS) and inferior joint spaces (IJS), using a human cadaver.

STUDY DESIGN

The study utilized five cadavers donated by members of our university. The cadaver's left side was aimed at the SJS, while the right side was at the IJS. Nonionic contrast was injected into each joint using a crossing technique, with the linear ultrasound probe placed parallel to the long axis of the mandibular branch and punctured perpendicularly into the joint cavity. Cone-beam computed tomography scans assessed both the TMJs examining discs and other components for damage using a gross anatomical technique.

RESULTS

Computed tomography images confirmed successful contrast agent injection into all joint spaces without damaging the articular discs or cartilage of the mandibular head.

CONCLUSIONS

Our findings suggest that the ultrasound device can selectively puncture the TMJ in the SJS and IJS. In the future, the success rate is expected to improve with additional cadaver punctures. We aim to establish this technique as a viable treatment method that can be performed by oral surgeons with limited clinical experience in cadaver surgery training and a surgical technique training program using human cadavers.

Effect of extracorporeal shock wave therapy and ultrasound-guided percutaneous lavage in reducing the pain of rotator cuff calcific tendinopathy; an updated systematic review and meta-analysis

Background

Extracorporeal shockwave therapy (ESWT) and ultrasound-guided percutaneous lavage (UGPL or barbotage) are among those used to treat the pain of rotator cuff calcific tendinopathy (RCCT). This meta-analysis was done to review the effect ESWT and UGPL in reducing the pain of RCCT.

Methods

A comprehensive search was done based on the PRISMA. PubMed, Web of Science, Scopus, Cochrane Library and Google Scholar were reviewed for articles published by Feb 1, 2024, on ESWT vs. UGPL. The main keywords searched are as follows: "rotator cuff calcific tendinopathy", "tendinitis", " ESWT", " ultrasound-guided percutaneous lavage", " RCCT ″, " UGPL", " extracorporeal shock wave therapy" and titles or abstracts may contain one or a mix of these elements. This study was registered at PROSPERO with code" CRD42022385068". STATA version 13 was applied to analyze.

Results

In general, 779 patients from 22 studies were analyzed. The mean age was 51.85 ± 3.41 years. The patients were referred after 18.69 months of suffering from tendinopathy symptoms. Right-sided and supraspinatus locations were affected more. ESWT has been effective in a decrease of calcium deposit (-1.70 SMD after 1 week for ESWT, -0.96 SMD after 12 weeks for ESWT and -1.20 SMD after 12 weeks UPGL). ESWT has been effective in decreasing VAS by -4.32 SMD after 1 week while UPGL showed -0.23 SMD reductions in VAS After 1 week but in time >1 week, UPGL showed better effect by more reduction in VAS. ESWT has been effective in an increase of CMS by 1.60 SMD after 4-6 weeks, by 1.79 SMD after 12 weeks, by 2.44 SMD after 24 weeks, and 2.53 SMD after 48 weeks.

Conclusion

Based on the results, ultrasound-guided lavage is more effective in reducing pain than ESWT, and this effect becomes more evident in the long term. In terms of CMS score, over time, the efficiency of ESWT becomes more visible. In long-term follow-up, UPGL had a better effect on the calcium deposit reduction.

Advances in bioadhesives for meniscal repair: A comprehensive review and criteria for the ideal candidate

The latest studies agree that meniscal tears that require surgery should be repaired whenever possible to avoid early-onset osteoarthritis secondary to meniscectomy. Unfortunately, there are several limitations associated with meniscal sutures, making it difficult to put into practice the theory behind the concept of saving the meniscus. Meanwhile, there is an exponential growth in the use of tissue adhesives for surgery, but finding one suited to meniscal repair remains a struggle. This review has two main goals (1) to compile the various bioadhesives used in this field and (2) to list the criteria for an ideal meniscal bioadhesive. The review was conducted in PubMed, Google Scholar, and Web of Science in November 2023 without date restrictions. The inclusion criteria were: Studies published in English and focusing on meniscal repair using bioadhesives. The exclusion criteria were: Studies published in languages other than English. Adhesives used in combination with sutures, as the aim was to determine the adhesive's capabilities for meniscal repair alone. Synthetic adhesives such as polycyanoacrylates, polyethylene glycol, polyurethanes, and polyesters. Among the 11 bioadhesives found, fibrin is the only one that has been studied in humans. There are advantages and disadvantages to all the bioadhesives identified but none that fully meet the requirements for meniscal repair. The anatomy of meniscal tissue is complex and poses unique challenges that are compounded by arthroscopic stresses. The future of meniscal repair probably lies in combining the advantages of several bioadhesives, and this area should be the focus of future research.

The method of femoral tunnel drilling in anterior cruciate ligament reconstruction does not influence the return to sport rate

Background

Limited evidence is available comparing the modified transtibial (MTT) and transportal (TP) techniques in anterior cruciate ligament (ACL) reconstruction and their impact on returning to sports participation. The objective was to analyze the outcomes after arthroscopic reconstruction of the ACL in recreational athletes with a 2-year postoperative follow-up, comparing the MTT and TP techniques, based on the method used to drill the femoral tunnel.

Hypotesis

The rate of return to sport would be comparable regardless of the surgical technique used.

Material and methods

A retrospective study was conducted with 66 patients who underwent arthroscopic monofascicular ACL reconstruction between September 2016 and March 2020. Patients aged between 16 and 50 years old, recreational athletes at Tegner levels 6 and 7, with a 2-year follow-up were included. Groups were established for comparative analysis (MTT vs TP) based on the method for drilling the femoral tunnel. The main outcome variable was the return to sport at the same level. Secondary variables included patient satisfaction evaluated with a visual analogue scale (VAS) and knee function according to the Lysholm scale.

Results

At 2 years of postoperative follow-up, the return to sport rate was 30.3 % in the MTT group and 33.3 % in the TP group (p = 0.791). There were no significant differences between both groups in patient satisfaction (p = 0.664) and knee function (p = 0.113).

Conclusion

Drilling the femoral tunnel with the MTT and TP techniques did not influence the rate of return to sport, patient satisfaction, and knee function in recreational athletes with 2 years of postoperative follow-up.

Level of evidence

III.

Effect of post-operative NSAID use on rotator cuff repair outcomes

Background

The impact of non-steroidal anti-inflammatory drugs (NSAIDs) on rotator cuff repair is an ongoing area of study within orthopedics, with conflicting results in current literature. Despite concerns over the deleterious effects of NSAIDs on rotator cuff healing, they are becoming an integral part of a multimodal post-operative pain control regiment. The purpose of this study was to compare post-operative patient-reported outcomes (PROs), complications rates, and retear rates of arthroscopic rotator cuff repairs in patients using ibuprofen post-operatively to those who abstained from NSAIDs for six weeks after surgery. It was hypothesized that a short course of ibuprofen post-operatively would not lead to inferior PRO scores, increased retear rates, nor increased complication rates after arthroscopic rotator cuff repair.

Methods

Patients of the primary surgeon who underwent arthroscopic rotator cuff repair between 2012 and 2022 were evaluated by retrospective chart review. In May 2017 the primary surgeon changed his protocol from avoiding NSAIDs for six weeks after surgery to routinely prescribing two weeks of Ibuprofen 800 mg TID post-operatively. Patients who avoided NSAIDs for six weeks were compared to patients who were prescribed NSAIDs post-operatively. Patient demographic data, pre-operative MRI results, pre-operative and post-operative PROs were collected from the EMR. Additionally, post-operative complications and repair failures requiring reoperation within one year were evaluated.

Results

125 patients met inclusion criteria for this study with 36 patients in the NSAID group and 89 in the no NSAID group. When comparing improvement in PROs, the NSAID group reached MCID at one year in 83.8 % of patients and the no NSAID group reached MCID at one year in 73.9 % of patients. There was no significant difference between the groups in reaching MCID improvement at one year (p = 0.471). Five post-operative complications were reported in the no NSAID group and two in the NSAID group (5.7 % vs 5.4 %, respectively, p = 0.827). Finally, there was no significant difference in the percentage of post-operative rotator cuff repair failures requiring revision in the first year between the groups (2.3 % vs 2.7 %, p = 1.000).

Conclusion

There was no difference in percent of patients improving their PRO by the MCID between the groups that used ibuprofen and the group that did not. There was also no difference in post-operative complication rates and rates of symptomatic retear requiring reoperation between the groups. This supports that a short course of NSAIDs post-operatively, specifically ibuprofen, after rotator cuff repair does not increase reoperation rates nor lead to a clinically significant decrease in PROs at one year.

Liver tissue engineering using decellularized scaffolds: Current progress, challenges, and opportunities

Liver transplantation represents the only definitive treatment for patients with end-stage liver disease. However, the shortage of liver donors provokes a dramatic gap between available grafts and patients on the waiting list. Whole liver bioengineering, an emerging field of tissue engineering, holds great potential to overcome this gap. This approach involves two main steps; the first is liver decellularization and the second is recellularization. Liver decellularization aims to remove cellular and nuclear materials from the organ, leaving behind extracellular matrices containing different structural proteins and growth factors while retaining both the vascular and biliary networks. Recellularization involves repopulating the decellularized liver with appropriate cells, theoretically from the recipient patient, to reconstruct the parenchyma, vascular tree, and biliary network. The aim of this review is to identify the major advances in decellularization and recellularization strategies and investigate obstacles for the clinical application of bioengineered liver, including immunogenicity of the designed liver extracellular matrices, the need for standardization of scaffold fabrication techniques, selection of suitable cell sources for parenchymal repopulation, vascular, and biliary tree reconstruction. In vivo transplantation models are also summarized for evaluating the functionality of bioengineered livers. Finally, the regulatory measures and future directions for confirming the safety and efficacy of bioengineered liver are also discussed. Addressing these challenges in whole liver bioengineering may offer new solutions to meet the demand for liver transplantation and improve patient outcomes.

Radial extracorporeal shockwave promotes osteogenesis-angiogenesis coupling of bone marrow stromal cells from senile osteoporosis via activating the Piezo1/CaMKII/CREB axis

Radial extracorporeal shockwave (r-ESW) and bone marrow stromal cells (BMSCs) have been reported to alleviate senile osteoporosis (SOP), but its regulatory mechanism remains unclear. In this study, we firstly isolated human BMSCs from bone marrow samples and treated with varying r-ESW doses. And we found that r-ESW could enhance the proliferation of SOP-BMSCs in a dose-dependent manner by EdU assay. Subsequently, the impact of r-ESW on the proliferation, apoptosis and multipotency of BMSCs was assessed. And the outcomes of flow cytometry, Alizarin red S (ARS), and tube formation test demonstrated that the optimal shockwave obviously boosted SOP-BMSCs osteogenesis and angiogenesis but exhibited no significant impact on cell apoptosis. Additionally, the signaling of Piezo1 and CaMKII/CREB was examined by Western blotting, qPCR and immunofluorescence. And the results showed that r-ESW promoted the expression of Piezo1, increased intracellular Ca2+ and activated the CaMKII/CREB signaling pathway. Then, the application of Piezo1 siRNA hindered the r-ESW-induced enhancement ability of osteogenesis coupling with angiogenesis of SOP-BMSCs. The use of the CaMKII/CREB signaling pathway inhibitor KN93 suppressed the Piezo1-induced increase in osteogenesis and angiogenesis in SOP-BMSCs. Finally, we also found that r-ESW might alleviate SOP in the senescence-accelerated mouse prone 6 (SAMP6) model by activating Piezo1. In conclusion, our research offers experimental evidence and an elucidated underlying molecular mechanism to support the use of r-ESW as a credible rehabilitative treatment for senile osteoporosis.

The application of proximal tibial anterior closing wedge osteotomy in anterior cruciate ligament reconstruction

Introduction

Posterior tibial slope (PTS) plays a vital role in knee stability. PTS of more than 12° may be considered with increased strain on the native anterior cruciate ligament (ACL) fibers. To handle the instability caused by changes in PTS degree, Proximal Tibial Anterior Closing Wedge Osteotomy (PT-ACWO) is adopted by surgeons.

Methods

Between October 2015 and October 2019, our department conducted a retrospective analysis of patients who experienced anterior cruciate ligament reconstruction (ACLR) graft failures, with a particular focus on pathological PTS. The time from initial ACLR to revision ranged from 1 to 10 years, with a mean of 2.5 years. Radiological assessments of PTS were conducted, and outcomes were quantified using the International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity scale. The surgical technique and the use of 3D Patient-Specific Instrumentation (PSI) were outlined. Preoperative imaging included the use of Kirschner wires to establish tibial plateau reference points, and 3D-PSI was employed to guide the location and depth of the tibial osteotomy, which was performed obliquely. In a notable instance, a novel tibial tunnel was mapped out, and ortho-bridge system (OBS) fixation was utilized to ensure adequate space for the new tunnel.

Results

In a cohort of seven patients with a mean follow-up of 28.1 months, a significant reduction in PTS was noted postoperatively (median [interquartile range, IQR], from 15.27° [13.46°, 16.60°] to 6.25° [5.89°, 6.78°]; P = 0.002). IKDC score improved to 85.10 (80.25, 88.10), P < 0.001; the Lysholm score to 88.00 (73.00, 90.50), P < 0.001; and the Tegner score to 8.00 (7.20, 8.05), P = 0.025 at final follow-up. Skin incision healing delays occurred in two instances, yet achieved closure by six weeks. Radiographs at three months demonstrated faster bone healing in oblique osteotomies than transverse ones. Knee joint stability was maintained, with no additional complications or evidence of instability noted. Magnetic resonance imaging (MRI) confirmed graft integrity in all patients, without signs of enlargement or mispositioning at last observation.

Conclusion

An augmented PTS angle exceeding 12 may constitute a potential etiology for the failure of ACLR grafts. In such patients, the implementation of ACLR combined with PT-ACWO could mitigate the risk of surgical failure during initial ACLR or subsequent revision procedures.

Mechanical loading on cell-free polymer composite scaffold enhances in situ regeneration of fully functional Achilles tendon in a rabbit model

Traditional tendon engineering using cell-loaded scaffold has limited application potential due to the need of autologous cells. We hypothesize that potent mechanical loading can efficiently induce in situ Achilles tendon regeneration in a rabbit model by using a cell-free porous composite scaffold. In this study, melt-spinning was used to fabricate PGA (polyglycolic acid) and PLA (polylactic acid) filament fibers as well as non-woven PGA fibers. The PLA/PGA (4:2) filament fibers were further braided into a hybrid yarn，which was knitted into a PLA/PGA tubular mesh with potent mechanical property for sustaining natural tendon strain. The results showed that a complete cross-section of Achilles tendon created a model of full mechanical loading on the bridging scaffold, which could efficiently induce in situ tendon regeneration by promoting host cell infiltration, matrix production and tissue remodeling. Histologically, mechanical loading assisted in forming parallel aligned collagen fibers and tenocytes in a fashion similar to those of native tendon. Transmission electron microscope further demonstrated that mechanical strain induced collagen fibril development by increasing fibril diameter and forming bipolar structure, which resulted in enhanced mechanical properties. Interestingly, the synergistic effect between mechanical loading and hyaluronic acid modification was also observed on the induced tenogenic differentiation of infiltrated host fibroblasts. In conclusion, potent mechanical loading is the key inductive microenvironment for in situ tendon regeneration for this polymer-based composite scaffold with proper matrix modification, which may serve as a universal scaffold product for tendon regeneration.

Processing speed and its association with working memory and episodic memory 3-6 months after pediatric mild traumatic brain injury

OBJECTIVE

Following mild traumatic brain injury (mTBI), children show reduced processing speed (PS). Evidence suggests that slowed PS after TBI is associated with working memory deficits. Our aim was to investigate several forms of PS and to examine its impact on working and episodic memory performance in children after mTBI.

METHOD

We included data of 64 children after mTBI and 57 healthy control children aged 8-16 years. PS (Color Naming, Coding, Symbol Search, Alertness) was compared between groups 1 week (T1) and 3-6 months (T2) after the injury; working and episodic memory outcome was compared between groups at T2.

RESULTS

Alertness at T1 and Color Naming at T1 and T2 were significantly reduced following mTBI compared to controls, although most group differences in PS disappeared when patients with previous impairments and mTBI were excluded. PS was predictive for episodic and working memory performance 3-6 months after injury, whereas group was a significant predictor of working memory.

CONCLUSIONS

Compared to healthy controls, children after mTBI showed reduced performance in verbal PS, which was associated with working memory. In children who are symptomatic after mTBI, diagnostic screening of PS could be helpful in identifying patients that could profit from speed-improving strategies.

Effects of mTBI with loss of consciousness on neurobehavioral symptoms, depression, and insomnia in former collegiate and NFL football athletes

OBJECTIVE

Considering that diagnostic decisions about mTBI are often predicated on clinical symptom criteria, it is imperative to determine which initial presentation features of mTBI have prognostic significance for identifying those at high risk for long-term functional impairment.

SETTING

Zoom interview Participants: Male, former NCAA Division I, and professional-level National Football League (NFL) athletes (n = 177) between the ages of 27 and 85 (M = 54.1, SD = 14.7).

DESIGN

Cross-sectional case-control. Main Measures: History of mild TBI, history of loss of consciousness (LOC), depression symptoms, insomnia, neurobehavioral symptoms.

RESULTS

Number of mTBI exposures did not predict neurobehavioral symptoms (B = 0.21, SE = 0.18, p = 0.23), but number of mTBI + LOC events did (B = 2.27, SE = 0.64, p = <.001). Further analysis revealed that the number of mTBI + LOC events predicted neurobehavioral symptoms indirectly through both depression (B = 0.85, 95% CI = [0.27, 1.52) and insomnia (B = 0.81, 95% CI = [0.3, 1.4]). Further, the direct effect of mTBI + LOC events on neurobehavioral symptoms became non-significant when depression and insomnia were added to the model (B = 0.78, SE = 0.45, p = 0.08).

CONCLUSIONS

Findings support LOC at time of injury as an important predictor of long-term outcomes. Additionally, results suggest depression and insomnia as potential mediators in the association between mTBI + LOC and neurobehavioral symptoms. These findings provide justification for early depression and insomnia symptom monitoring following mTBI + LOC.