A hop testing alternative for functional performance following anterior cruciate ligament reconstruction.

The purpose of this work was to provide a simple method to determine reactive strength during the 6-meter timed hop test (6mTH) and evaluate its association with isokinetic peak torque in patients following anterior cruciate ligament reconstruction (ACLR). Twenty-nine ACLR patients who were at least four months from surgery were included in this analysis. Participants were brought into the laboratory on one occasion to complete functional testing. Quadriceps and hamstring isokinetic testing was completed bilaterally at 60, 180, and 300 deg∙s-1, using extension peak torque from each speed as the outcome measure. The 6mTH was completed bilaterally using a marker-based motion capture system, and reactive strength ratio (RSR) was calculated from the vertical velocity of the pelvis during the test. An adjustment in RSR was made using the velocity of the 6mTH test to account for different strategies employed across participants. Repeated measures correlations were used to determine associations among isokinetic and hop testing variables. A two-way mixed analysis of variance was used to determine differences in isokinetic and hop testing variables between operated and non-operated legs and across male and female participants. Moderate positive associations were found between RSR (and adjusted RSR) and isokinetic peak torque at all speeds (r = .527 to .577). Mean comparisons showed significant main effects for leg and sex. Patients showed significant deficits in their operated versus non-operated legs in all isokinetic and hop testing variables, yet only isokinetic peak torque and timed hop time showed significant differences across male and female groups. Preliminary results are promising but further development is needed to validate other accessible technologies available to calculate reactive strength during functional testing after ACLR. Pending these developments, the effects of movement strategies, demographics, and levels of participation on RSR can then be explored to translate this simple method to clinical environments.

Mechanical loading and orthobiologic therapies in the treatment of post-traumatic osteoarthritis (PTOA): a comprehensive review.

The importance of mechanical loading and its relationship to orthobiologic therapies in the treatment of post-traumatic osteoarthritis (PTOA) is beginning to receive attention. This review explores the current efficacy of orthobiologic interventions, notably platelet-rich plasma (PRP), bone marrow aspirate (BMA), and mesenchymal stem/stromal cells (MSCs), in combating PTOA drawing from a comprehensive review of both preclinical animal models and human clinical studies. This review suggests why mechanical joint loading, such as running, might improve outcomes in PTOA management in conjunction with orthiobiologic administration. Accumulating evidence underscores the influence of mechanical loading on chondrocyte behavior and its pivotal role in PTOA pathogenesis. Dynamic loading has been identified as a key factor for optimal articular cartilage (AC) health and function, offering the potential to slow down or even reverse PTOA progression. We hypothesize that integrating the activation of mechanotransduction pathways with orthobiologic treatment strategies may hold a key to mitigating or even preventing PTOA development. Specific loading patterns incorporating exercise and physical activity for optimal joint health remain to be defined, particularly in the clinical setting following joint trauma.

Comparing MRI and arthroscopic appearances of common knee pathologies: A pictorial review.

Knee pathology, including anterior cruciate ligament (ACL) tears, meniscal tears, articular cartilage lesions, and intra-articular masses or cysts are common clinical entities treated by orthopedic surgeons with arthroscopic surgery. Preoperatively, magnetic resonance imaging (MRI) is now standard in confirming knee pathology, particularly detecting pathology less evident with history and physical examination alone. The radiologist's MRI interpretation becomes essential in evaluating intra-articular knee structures. Typically, the radiologist that interprets the MRI does not have the opportunity to view the same pathology arthroscopically. Thus, the purpose of this article is to illustratively reconcile what the orthopedic surgeon sees arthroscopically with what the radiologist sees on magnetic resonance imaging when viewing the same pathology. Correlating virtual and actual images can help better understand pathology, resulting in more accurate MRI interpretations. In this article, we present and review a series of MR and correlating arthroscopic images of ACL tears, meniscal tears, chondral lesions, and intra-articular masses and cysts. Short teaching points are included to highlight the importance of radiological signs and pathological MRI appearance with significant clinical and arthroscopic findings.

Video analysis of anterior cruciate ligament tears of professional basketball players in the National Basketball Association.

BACKGROUND: Anterior cruciate ligament (ACL) tears are devastating for elite athletes, including those in the National Basketball Association (NBA). The purpose of this study was to describe common in-game mechanisms of injury, playing situations, and anatomic positioning of players who sustained an ACL injury in the NBA. METHODS: ACL tears which occurred in NBA games during the previous 16 seasons (2007-2022) and had accessible video clips were identified through publicly available reports. RESULTS: Thirty-one ACL tears were identified with quality videos available. Nearly all players were on offense (93.5%, 29/31). Most ACL tears (29/31, 93.5%) did not involve direct contact to the injured extremity. The most common physical activity at the time of injury was landing from any type of jump (45.2%, 14/31). Anatomically, the knee was frequently in early flexion (58.8%, 10/17) and abducted (77.4%, 24/31); the foot was commonly abducted (87.1%, 27/31); and the hip was usually abducted (64.5%, 20/31) and flexed (80.6%, 25/31). Almost all players had another individual near them at the time of injury, with 90.3% (28/31) and 96.8% (30/31) having someone within 2ft and 5ft. CONCLUSIONS: Most ACL tears occurred inside the lane, regardless of mechanism of injury (26/31, 83.9%). ACL tears in the NBA were primarily not due to direct contact of the injured extremity but did have common anatomic patterns. The findings of this study can be used in the future to help reduce the risk of injury through the adaptation of current training activities.

The Surgical Management of NCAA Division 1 College Football Injuries Post COVID-19: A Single Institution Retrospective Review.

ABSTRACT: Cohen, JL, Cade, WH, Harrah, TC, Costello II, JP, and Kaplan, LD. The surgical management of NCAA Division 1 college football injuries post COVID-19: A single institution retrospective review. J Strength Cond Res 38(5): 906-911, 2024-The unprecedented COVID-19 pandemic had a significant impact on college football operations, including athletes' training regimens. As a result of these changes, concern for increased injury susceptibility post COVID-19 regulations has become a point of discussion. The current study sought to evaluate the incidence of surgical injury among NCAA Division 1 college football players at the authors' institution during the first full season after start of the COVID-19 pandemic compared with previous years. Retrospective chart review was performed for all players who sustained injuries requiring surgery while a member of the NCAA Division 1 football program during the 2009-2021 seasons. A p -value of ≤0.05 was used to determine significance. A total of 23 surgical injuries occurred in 22 players during the 2021 season compared with 121 in 118 players in the 12 previous seasons combined ( p = 0.0178; RR = 1.47). There was a significant increase in shoulder injuries ( n = 13 vs. n = 31; p = <0.0001; RR = 3.05) and specifically a significant increase in labral tears ( n = 10 vs. n = 30; p = 0.0003; RR = 2.74). No difference was seen in knee injuries ( n = 10 vs. n = 77; p = 0.27; RR = 1.35) and specifically no difference in anterior cruciate ligament injuries ( n = 3 vs. n = 31; p = 0.77; RR = 1.17). This phenomenon is multifactorial in nature, but alterations to players' training and preparations because of the COVID-19 pandemic likely resulted in suboptimal conditioning, leading to the increased incidence of surgical injuries emphasizing the importance of adequate strength training and conditioning.

Effects of COVID-19 on Rate of Injury and Position-Specific Injury During the 2020 National Football League Season.

ABSTRACT: Costello II, JP, Wagner, JD, Dahl, VA, Cohen, JL, Reuter, AM, and Kaplan, LD. Effects of COVID-19 on rate of injury and position-specific injury during the 2020 National Football League season. J Strength Cond Res 38(1): 97-104, 2024-Because of the COVID-19 pandemic, the National Football League (NFL) made changes to its operations for the 2020 season. We hypothesize an increase in the rate of injuries during the 2020 season. Publicly available data were reviewed to identify NFL injuries from the 2015-2020 seasons. Player position, description of injury, date of injury, and injury setting were recorded. p ≤ 0.05 was considered statistically significant. For the 2020 season, compared with the 2015-2019 seasons, there was an increased risk of injury during the regular season overall relative risk (RR) = 1.308 ( p < 0.05), week (W)1 RR = 7.33 ( p < 0.05), W1-6 RR = 1.964 ( p < 0.05), W7-12 RR = 1.8909 ( p < 0.05), and during the postseason overall RR = 1.1444 ( p < 0.05), calculated using analysis of variance. There was an overall increased risk of abdominal or core injuries RR = 1.248 ( p < 0.05), groin or hip injuries RR = 2.534 ( p < 0.05), and hamstring injuries RR = 3.644 ( p < 0.05). There was an increased risk of hamstring injuries in cornerbacks RR = 3.219 ( p < 0.05) and running backs RR = 1.1394 ( p < 0.05), hip or groin injuries in guards RR = 1.105 ( p < 0.05), Achilles tendon injuries in safeties RR = 1.6976 ( p < 0.05), quadriceps injuries in running backs RR = 1.6191 ( p < 0.05), and arm injuries in defensive tackles RR = 1.221 ( p < 0.05). There was an increase in the overall rate of injuries in the 2020 NFL season, both in the regular season and postseason, compared with the 2015-2019 seasons. The overall rate of abdominal or core, groin or hip, and hamstring injuries increased. Specific player positions saw unique increases in rates of injuries. These findings may be due to numerous operational changes implemented, such as reduced in-person training and the elimination of the preseason, leading to suboptimal, sports-specific conditioning and increased risk of musculoskeletal injury.

Acute Batter's Shoulder With Concomitant Superior Labrum from Anterior to Posterior Injury in a Collegiate Baseball Player.

An 18-year-old collegiate baseball player sustained an acute batter's shoulder injury causing a posterior shoulder dislocation with type IX 360° superior labrum from anterior to posterior tear. To the authors' knowledge, this description of batter's shoulder is not within the literature. The patient ultimately underwent arthroscopic labral repair and has fully returned to sport. In understanding the complexity of the shoulder during the batter's swing, this case demonstrates an expansion to the previously described pathophysiology of batter's shoulder.

The Effects of Modified Game Schedules on Injury Rates in the National Hockey League (NHL).

Background Due to the COVID-19 pandemic, many professional sports leagues such as the National Hockey League (NHL) made significant changes to their schedules and operating procedures. Changes included a modified 2019-2020 playoff format, the removal of the 2020-2021 preseason, and condensed game schedules. Though these modifications were made in an effort to protect players from COVID-19, they resulted in decreased training time and preparation. The purpose of this study was to assess the impact of these changes on the rate of player injuries in the NHL both after the resumption of the midseason stoppage and during the subsequent seasons. Hypothesis/purpose Changes to the NHL schedule amid the COVID-19 pandemic resulted in a significant increase in player injury rates. Methods NHL injuries were obtained from an NHL injury database for the 2018-2019 through the 2021-2022 seasons. The date of injury, date of return, injury description, player age, and player position were recorded. Injury rates were calculated as the number of total athlete injuries per 1000 game exposures (GEs). The primary outcome was the injury proportion ratio (IPR) when comparing the injury rates of the post-COVID-19 season with baseline seasons. Secondary measures analyzed injuries based on age, anatomic location, month in the season, position, length of injury, season-ending injuries, and recurring injuries. Results A total of 4604 injuries were recorded between 2018 and 2022. The modified 2019-2020 playoffs had significantly higher rates of injury (IPR = 1.84, 95% confidence interval {CI} = 1.36-2.49) with more game exposures per week. The 2020-2021 season had significantly higher rates of overall player injury compared to baseline seasons (IPR = 1.19, 95% CI = 1.09-1.30) and also had a higher rate of season-ending injuries (IPR = 1.71, 95% CI = 1.38-2.11). Most injuries occurred in the first few months of the 2020-2021 season. There was no significant difference in injury rate based on age group and no significant difference in the average length of injury between seasons. Conclusion Increases in injury rates could be due to decreased offseason training between seasons, the elimination of preseason games, and increased game density. Decreasing typical training timelines and eliminating the preseason to rapidly return to normal competition after unexpected events (pandemics, lockdowns, etc.) may pose a risk to player safety in the NHL. These findings should be considered before future schedule changes in professional hockey.

Impact of Quadriceps Tendon Graft Thickness on Electromechanical Delay and Neuromuscular Performance After ACL Reconstruction.

Background: Both partial- and full-thickness quadriceps tendon (QT) graft harvests are used for anterior cruciate ligament reconstruction (ACLR). Purpose: To evaluate the impact of QT graft harvest depth (full or partial thickness) on electromechanical delay (EMD), peak torque (PT), and rate of torque development (RTD) after ACLR. Study Design: Controlled laboratory study. Methods: A total of 26 patients who underwent either partial-thickness (n = 14) or full-thickness (n = 12) autograft QT ACLR were recruited between June and November 2021 (>1 year before participation). Patients performed isokinetic knee extension testing with surface electromyography of the quadriceps muscles. Mixed repeated-measures analysis of variance with least significant difference post hoc testing was used to determine significant differences (mean difference [MD] ± SE) or interactions for all variables. Results: A significant speed×depth interaction was seen for the vastus medialis (P = .005). Pairwise analyses showed significantly longer EMD for the partial-thickness graft than the full-thickness graft (MD ± SE, 19.92 ± 6.33 ms; P = .006). In the partial-thickness graft, the EMD was significantly longer at 90 deg/s versus 180 deg/s (MD ± SE, 19.11 ± 3.95 ms; P < .001) and 300 deg/s (MD ± SE, 16.43 ± 5.30 ms; P = .006). For PT, the full-thickness graft had a significantly lower PT on the operated versus nonoperated side at all speeds (MD ± SE: 90 deg/s, -57.0 ± 10.5 N·m, P < .001; 180 deg/s, -26.0 ± 10.2 N·m, P = .020; 300 deg/s, -20.3 ± 8.9 N·m, P = .034). For RTD, the full-thickness graft showed significantly Slower RTD for the operated versus nonoperated side at all time points (MD ± SD: RTD0-25 (0-25% of the range of motion), -131.3 ± 50.9 N·m/s, P = .018; RTD25-50, -197.0 ± 72.5 N·m/s, P = .014; RTD50-75, -113.3 ± 39.8 N·m/s, P = .013; RTD75-100, -149.4 ± 35.9 N·m/s, P < .001). Conclusion: Compared with partial-thickness QT, full-thickness QT showed a shorter vastus medialis EMD at higher loading, and therefore greater stiffness, as well as slower RTD and lower PT across all testing speeds. Clinical Relevance: The impact of full-thickness QT autograft on EMD and neuromuscular performance should be considered for ACLR.

Mesenchymal Stem/Stromal Cell-Derived Small Extracellular Vesicles (MSC-sEVs): A Promising Treatment Modality for Diabetic Foot Ulcer.

Diabetic foot ulcer (DFU) is associated with neuropathy and/or peripheral artery disease of the lower limb in diabetic patients, affecting quality of life and leading to repeated hospitalizations and infections [...].

Augmented Reality for Perioperative Anxiety in Patients Undergoing Surgery: A Randomized Clinical Trial.

Importance: Both augmented reality (AR) and virtual reality (VR) have had increasing applications in medicine, including medical training, psychology, physical medicine, rehabilitation, and surgical specialties, such as neurosurgery and orthopedic surgery. There are little data on AR's effect on patients' anxiety and experiences. Objective: To determine whether the use of an AR walkthrough effects patient perioperative anxiety. Design, Setting, and Participants: This randomized clinical trial was conducted at an outpatient surgery center in 2021 to 2022. All patients undergoing elective orthopedic surgery with the senior author were randomized to the treatment or control group. Analyses were conducted per protocol. Data analysis was performed in November 2022. Intervention: AR experience explaining to patients what to expect on their day of surgery and walking them through the surgery space. The control group received the standard educational packet. Main Outcomes and Measures: The main outcome was change in State-Trait Anxiety Inventory (STAI) from the screening survey to the preoperative survey. Results: A total of 140 patients were eligible, and 45 patients either declined or were excluded. Therefore, 95 patients (63 [66.3%] male; mean [SD] age, 38 [16] years) were recruited for the study and included in the final analysis; 46 patients received the AR intervention, and 49 patients received standard instructions. The AR group experienced a decrease in anxiety from the screening to preoperative survey (mean score change, -2.4 [95% CI, -4.6 to -0.3]), while the standard care group experienced an increase (mean score change, 2.6 [95% CI, 0.2 to 4.9]; P = .01). All patients postoperatively experienced a mean decrease in anxiety score compared with both the screening survey (mean change: AR, -5.4 [95% CI, -7.9 to -2.9]; standard care, -6.9 [95% CI, -11.5 to -2.2]; P = .32) and preoperative survey (mean change: AR, -8.0 [95% CI, -10.3 to -5.7]; standard care, -4.2 [95% CI, -8.6 to 0.2]; P = .19). Of 42 patients in the AR group who completed the postoperative follow-up survey, 30 (71.4%) agreed or strongly agreed that they enjoyed the experience, 29 (69.0%) agreed or strongly agreed that they would recommend the experience, and 28 (66.7%) agreed or strongly agreed that they would use the experience again. No differences were observed in postoperative pain levels or narcotic use. Conclusions and Relevance: In this randomized clinical trial, the use of AR decreased preoperative anxiety compared with traditional perioperative education and handouts, but there was no significant effect on postoperative anxiety, pain levels, or narcotic use. These findings suggest that AR may serve as an effective means of decreasing preoperative patient anxiety. Trial Registration: ClinicalTrials.gov Identifier: NCT04727697.

Therapeutic Perspectives for Inflammation and Senescence in Osteoarthritis Using Mesenchymal Stem Cells, Mesenchymal Stem Cell-Derived Extracellular Vesicles and Senolytic Agents.

Osteoarthritis (OA) is the most common cause of disability worldwide among the elderly. Alarmingly, the incidence of OA in individuals less than 40 years of age is rising, likely due to the increase in obesity and post-traumatic osteoarthritis (PTOA). In recent years, due to a better understanding of the underlying pathophysiology of OA, several potential therapeutic approaches targeting specific molecular pathways have been identified. In particular, the role of inflammation and the immune system has been increasingly recognized as important in a variety of musculoskeletal diseases, including OA. Similarly, higher levels of host cellular senescence, characterized by cessation of cell division and the secretion of a senescence-associated secretory phenotype (SASP) within the local tissue microenvironments, have also been linked to OA and its progression. New advances in the field, including stem cell therapies and senolytics, are emerging with the goal of slowing disease progression. Mesenchymal stem/stromal cells (MSCs) are a subset of multipotent adult stem cells that have demonstrated the potential to modulate unchecked inflammation, reverse fibrosis, attenuate pain, and potentially treat patients with OA. Numerous studies have demonstrated the potential of MSC extracellular vesicles (EVs) as cell-free treatments that comply with FDA regulations. EVs, including exosomes and microvesicles, are released by numerous cell types and are increasingly recognized as playing a critical role in cell-cell communication in age-related diseases, including OA. Treatment strategies for OA are being developed that target senescent cells and the paracrine and autocrine secretions of SASP. This article highlights the encouraging potential for MSC or MSC-derived products alone or in combination with senolytics to control patient symptoms and potentially mitigate the progression of OA. We will also explore the application of genomic principles to the study of OA and the potential for the discovery of OA phenotypes that can motivate more precise patient-driven treatments.

CD10-Bound Human Mesenchymal Stem/Stromal Cell-Derived Small Extracellular Vesicles Possess Immunomodulatory Cargo and Maintain Cartilage Homeostasis under Inflammatory Conditions.

The onset and progression of human inflammatory joint diseases are strongly associated with the activation of resident synovium/infrapatellar fat pad (IFP) pro-inflammatory and pain-transmitting signaling. We recently reported that intra-articularly injected IFP-derived mesenchymal stem/stromal cells (IFP-MSC) acquire a potent immunomodulatory phenotype and actively degrade substance P (SP) via neutral endopeptidase CD10 (neprilysin). Our hypothesis is that IFP-MSC robust immunomodulatory therapeutic effects are largely exerted via their CD10-bound small extracellular vesicles (IFP-MSC sEVs) by attenuating synoviocyte pro-inflammatory activation and articular cartilage degradation. Herein, IFP-MSC sEVs were isolated from CD10High- and CD10Low-expressing IFP-MSC cultures and their sEV miRNA cargo was assessed using multiplex methods. Functionally, we interrogated the effect of CD10High and CD10Low sEVs on stimulated by inflammatory/fibrotic cues synoviocyte monocultures and cocultures with IFP-MSC-derived chondropellets. Finally, CD10High sEVs were tested in vivo for their therapeutic capacity in an animal model of acute synovitis/fat pad fibrosis. Our results showed that CD10High and CD10Low sEVs possess distinct miRNA profiles. Reactome analysis of miRNAs highly present in sEVs showed their involvement in the regulation of six gene groups, particularly those involving the immune system. Stimulated synoviocytes exposed to IFP-MSC sEVs demonstrated significantly reduced proliferation and altered inflammation-related molecular profiles compared to control stimulated synoviocytes. Importantly, CD10High sEV treatment of stimulated chondropellets/synoviocyte cocultures indicated significant chondroprotective effects. Therapeutically, CD10High sEV treatment resulted in robust chondroprotective effects by retaining articular cartilage structure/composition and PRG4 (lubricin)-expressing cartilage cells in the animal model of acute synovitis/IFP fibrosis. Our study suggests that CD10High sEVs possess immunomodulatory miRNA attributes with strong chondroprotective/anabolic effects for articular cartilage in vivo. The results could serve as a foundation for sEV-based therapeutics for the resolution of detrimental aspects of immune-mediated inflammatory joint changes associated with conditions such as osteoarthritis (OA).

The roles and therapeutic potentialof mesenchymal stem/stromal cells and their extracellular vesicles in tendinopathies.

Tendinopathies encompass a highly prevalent, multi-faceted spectrum of disorders, characterized by activity-related pain, compromised function, and propensity for an extended absence from sport and the workplace. The pathophysiology of tendinopathy continues to evolve. For decades, it has been related primarily to repetitive overload trauma but more recently, the onset of tendinopathy has been attributed to the tissue's failed attempt to heal after subclinical inflammatory and immune challenges (failed healing model). Conventional tendinopathy management produces only short-term symptomatic relief and often results in incomplete repair or healing leading to compromised tendon function. For this reason, there has been increased effort to develop therapeutics to overcome the tissue's failed healing response by targeting the cellular metaplasia and pro-inflammatory extra-cellular environment. On this basis, stem cell-based therapies have been proposed as an alternative therapeutic approach designed to modify the course of the various tendon pathologies. Mesenchymal stem/stromal cells (MSCs) are multipotent stem cells often referred to as "medicinal signaling cells" due to their immunomodulatory and anti-inflammatory properties that can produce a pro-regenerative microenvironment in pathological tendons. However, the adoption of MSCs into clinical practice has been limited by FDA regulations and perceived risk of adverse events upon infusion in vivo. The introduction of cell-free approaches, such as the extracellular vesicles of MSCs, has encouraged new perspectives for the treatment of tendinopathies, showing promising short-term results. In this article, we review the most recent advances in MSC-based and MSC-derived therapies for tendinopathies. Preclinical and clinical studies are included with comment on future directions of this rapidly developing therapeutic modality, including the importance of understanding tissue loading and its relationship to any treatment regimen.

The Associations Between Quadriceps Tendon Graft Thickness and Isokinetic Performance.

BACKGROUND: Anterior cruciate ligament reconstruction (ACLR) using the quadriceps tendon is an increasingly popular technique. Both partial-thickness quadriceps tendon (PT-Q) and full-thickness quadriceps tendon (FT-Q) graft depths are employed. HYPOTHESIS/PURPOSE: This study was designed to assess isokinetic peak torque, average power, and total work during knee extension in patients with FT-Q or PT-Q grafts for ACLR. We hypothesized that both groups would show lower isokinetic values for the operated side, with greater deficits in the FT-Q group than in the PT-Q group. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 26 patients who underwent ACLR with either an FT-Q or PT-Q graft were recruited between June 2021 and November 2021. Patients underwent isokinetic knee extension testing at > 1 year after surgery. Mixed repeated-measures analysis of covariance with least square difference post hoc testing was used to determine significant differences or interactions for all variables. RESULTS: Peak torque was significantly lower for the operated limb than the nonoperated limb in the FT-Q group (mean difference [MD] ± standard error [SE], -38.6 ± 8.3 Ncm [95% CI, -55.7 to -21.5 Ncm]; P < .001; d = 0.90) but not in the PT-Q group (MD ± SE, -7.3 ± 7.7 Ncm [95% CI, -23.2 to 8.5 Ncm]; P = .348; d = 0.20). Similarly, average power for the operated limb was lower than that for the nonoperated limb in the FT-Q group (MD ± SE, -53.6 ± 13.4 W [95% CI, -81.3 to -26.9 W]; P < .001; d = 0.88) but not in the PT-Q group (MD ± SE, -4.1 ± 12.4 W [95% CI, -29.8 to 21.5 W]; P = .742; d = 0.07), and total work was lower for the operated limb compared with the nonoperated limb in the FT-Q group (MD ± SE, -118.2 ± 27.1 J [95% CI, -174.3 to -62.2 J]; P < .001; d = 0.96) but not in the PT-Q group (MD ± SE, -18.3 ± 25.1 J [95% CI, -70.2 to 33.6 J]; P = .472; d = 0.15). CONCLUSION: The FT-Q group showed significant deficits in the operated limb compared with the nonoperated limb for all isokinetic variables. In contrast, no significant differences were found between the nonoperated and operated limbs for the PT-Q group.

Hamstring injuries in the national football league: An epidemiological study.

Background: While numerous studies have evaluated National Football League injuries, there is limited literature evaluating hamstring injuries sustained in games. Our primary aim is to analyze the effect of player position on the relative incidence of hamstring injuries in the National Football League. Our secondary aims are to analyze the effects of field surface, week of the season, and short rest weeks. Methods: Official National Football League game books containing injury data from the 2013-2016 regular seasons were used. Data were analyzed to determine the incidence of hamstring injuries by field surface, rest, and week of the season. Field surface was considered either turf or grass. Short rest was considered four days. Relative incidence of hamstring injuries by position was performed with standardized incidence ratios. P values < 0.05 were considered statistically significant. Results: Seventy-eight qualifying hamstring injuries were identified and included in our analysis. Linebackers had the highest relative incidence per play with a standardized incidence ratio of 2.02 (CI: 1.14-2.91), followed by Defensive Backs (1.62; 95% CI: 1.14-1.62). Offensive linemen and defensive linemen had standardized incidence ratios significantly less than 1. Fifty-seven percent of hamstring injuries occurred on turf fields (p = 0.082). There was no significant difference between the proportion of hamstring injuries that occurred on short rest and the proportion of games played on short rest (p = 0.959). Hamstring injuries were not more likely to occur than the pooled group of all other types of injuries on short rest (p = 0.861). With a 17-week season, the mean week of hamstring injury was 8.05 (95% CI: 7.06-9.04), while the median week was 7.5. Conclusions: Linebackers and Defensive Backs have the highest relative incidence of hamstring injuries compared to other position groups, while offensive and defensive linemen have the lowest. Field surface and a short rest period did not show significance.

CD146+ Endometrial-Derived Mesenchymal Stem/Stromal Cell Subpopulation Possesses Exosomal Secretomes with Strong Immunomodulatory miRNA Attributes.

The perivascular localization of endometrial mesenchymal stem/stromal cells (eMSC) allows them to sense local and distant tissue damage, promoting tissue repair and healing. Our hypothesis is that eMSC therapeutic effects are largely exerted via their exosomal secretome (eMSC EXOs) by targeting the immune system and angiogenic modulation. For this purpose, EXOs isolated from Crude and CD146+ eMSC populations were compared for their miRNA therapeutic signatures and immunomodulatory functionality under inflammatory conditions. eMSC EXOs profiling revealed 121 in Crude and 88 in CD146+ miRNAs, with 82 commonly present in both populations. Reactome and KEGG analysis of miRNAs highly present in eMSC EXOs indicated their involvement among others in immune system regulation. From the commonly present miRNAs, four miRNAs (hsa-miR-320e, hsa-miR-182-3p, hsa-miR-378g, hsa-let-7e-5p) were more enriched in CD146+ eMSC EXOs. These miRNAs are involved in macrophage polarization, T cell activation, and regulation of inflammatory cytokine transcription (i.e., TNF-α, IL-1ß, and IL-6). Functionally, stimulated macrophages exposed to eMSC EXOs demonstrated a switch towards an alternate M2 status and reduced phagocytic capacity compared to stimulated alone. However, eMSC EXOs did not suppress stimulated human peripheral blood mononuclear cell proliferation, but significantly reduced secretion of 13 pro-inflammatory molecules compared to stimulated alone. In parallel, two anti-inflammatory proteins, IL-10 and IL-13, showed higher secretion, especially upon CD146+ eMSC EXO exposure. Our study suggests that eMSC, and even more, the CD146+ subpopulation, possess exosomal secretomes with strong immunomodulatory miRNA attributes. The resulting evidence could serve as a foundation for eMSC EXO-based therapeutics for the resolution of detrimental aspects of tissue inflammation.

The 50 Most Cited Articles in Knee Medial Collateral Ligament Injury Research.

Background: Medial collateral ligament (MCL) injury is a common orthopaedic knee injury with a plethora of published articles regarding evaluation, treatment, and outcome. Purpose: To perform a comprehensive bibliometric analysis of the 50 most cited articles in MCL research. Study Design: Cross-sectional study. Methods: We performed a keyword search of the Institute for Scientific Information's Web of Knowledge database for the identification of articles published before September 2021 encompassing the MCL. The conducted search yielded 9534 articles. The results were then filtered using predetermined guidelines and criteria, and the 50 most cited articles were selected for analysis. Extracted data included title, authors, citation count, year of publication, topic, journal, article type, country of origin, and level of evidence. Results: The selected 50 articles ranged from 1976 to 2013. The largest proportion was classified as having level 4 evidence (n = 12; 24%). The majority of the articles were published in the decade from 2000 to 2009 (n = 17; 34%), followed by 1990 to 1999 (n = 16; 32%). The mean raw citation score per article was 133 (range, 74-422). The most popular topic discussed was surgical technique and outcome (n = 14; 28%), followed by anatomy and biomechanics (n = 13; 26%). Conclusion: This study provides a comprehensive and objective measure of the most cited articles on MCL research. Knowledge of the characteristics of these most influential articles improves the understanding of MCL injury and can guide discussion for future research.

Word of Mouth and Online Reviews Are More Influential Than Social Media for Patients When Selecting a Sports Medicine Physician.

Purpose: To (1) identify the percentage of patients seen in an orthopaedic sports medicine practice who use social media and (2) identify the role that social media has in physician selection as compared with other factors. Methods: After institutional review board approval was received, new patients aged 18 years or older who attended a single orthopaedic sports medicine office from February 2020 to May 2021 were identified for inclusion. Sociodemographic information was recorded, and each patient was asked to fill out a questionnaire that assessed social media usage and online resources used to choose and formulate opinions regarding the patient's provider. Results: Two hundred patients met the inclusion criteria and completed the questionnaire. Of these, 96.5% reported social media use. The most common online method of searching for and identifying a physician was Google (50.5%). Social media outlets such as Facebook, Instagram, or LinkedIn were only used 15.5% of the time to search for and select a physician. Older patients were more likely to use recommendations from friends and family in their consideration when selecting a physician. Conclusions: Despite almost all participants stating that they use social media, only 15.5% of patients reported that they used social media to search for and potentially select their physician. Our study suggests that although social media can be a helpful tool for patient education, other factors such as physician education and physician reputation through word-of-mouth referrals, online reviews, and online ratings seem to play a larger role in the patient's selection of his or her physician. Clinical Relevance: This information may be of value to orthopaedic surgeons looking for ways to build their patient base, online reputation, or other aspects of their practice on the Internet.

Human infrapatellar fat pad mesenchymal stem cells show immunomodulatory exosomal signatures.

Within the human knee infrapatellar fat pad (IFP) and synovium, resident synoviocytes and macrophages contribute to the onset and progression of inflammatory joint diseases. Our hypothesis is that IFP-derived mesenchymal stem cells (IFP-MSC) robust immunomodulatory therapeutic effects are largely exerted via their exosomal (IFP-MSC EXOs) secretome by attenuating synoviocytes and macrophages pro-inflammatory activation. IFP-MSC EXOs showed distinct miRNA and protein immunomodulatory profiles. Reactome analysis of 24 miRNAs highly present in exosomes showed their involvement in the regulation of six gene groups, including immune system. Exosomes were enriched for immunomodulatory and reparative proteins that are involved in positive regulation of cell proliferation, response to stimulus, signal transduction, signal receptor activity, and protein phosphorylation. Stimulated synoviocytes or macrophages exposed to IFP-MSC EXOs demonstrated significantly reduced proliferation, altered inflammation-related molecular profiles, and reduced secretion of pro-inflammatory molecules compared to stimulated alone. In an acute synovial/IFP inflammation rat model, IFP-MSC EXOs therapeutic treatment resulted in robust macrophage polarization towards an anti-inflammatory therapeutic M2 phenotype within the synovium/IFP tissues. Based on these findings, we propose a viable cell-free alternative to MSC-based therapeutics as an alternative approach to treating synovitis and IFP fibrosis.