Open Access Journal of Sports Medicine最新文献

Background: Hip microinstability-subtle, symptomatic femoral head translation without dislocation-compromises the labral suction seal and accelerates chondrolabral wear. Clinical overlap with femoroacetabular impingement syndrome (FAIS) and borderline dysplasia delays recognition.

Purpose: To synthesize contemporary evidence on definitions, diagnosis, imaging, management, and outcomes in hip microinstability and to propose a phenotype-guided framework grounded in the labrum-capsule-ligamentum teres (LT) stability continuum.

Study design: Narrative review.

Methods: Peer-reviewed literature (2000-2025) focusing on biomechanical investigations, comparative cohorts, meta-analyses, and consensus statements on microinstability, hip capsular management, borderline dysplasia, and LT pathology.

Results: A four-pillar diagnostic approach improves accuracy. The Abduction-Hyperextension-External Rotation (AB-HEER) and Hyperextension-External Rotation (HEER) tests provide the highest single-test accuracy among exam maneuvers, whereas the prone instability test offers high specificity to rule in. The femoroepiphyseal acetabular roof (FEAR) index aids in risk stratification for borderline dysplasia but is position-sensitive. Arthroscopy with labral preservation and complete hip capsular closure improves patient-reported outcomes (PROs) and survivorship relative to non-closure. Iatrogenic cam over-resection can precipitate microinstability; femoral head-neck remplissage is a revision option to restore contour and sealing mechanics. In borderline dysplasia, both arthroscopy and periacetabular osteotomy (PAO) improve PROs when selection is phenotype-guided; PAO trends toward lower total hip arthroplasty (THA) conversion when undercoverage is the primary driver. Early postoperative circumduction is associated with lower rates of adhesion-related reoperation. Return-to-sport (RTS) decisions are criteria-based rather than time-based across successful programs.

Conclusion: A seal-first, close-second strategy, situated within a stability continuum, underpins contemporary care. Standardized definitions, objective laxity metrics, multicenter registries, and microinstability-specific rehabilitation/RTS batteries are needed to refine indications and improve durability; evidence specific to labral augmentation in microinstability remains limited.

Clinical relevance: Precise phenotyping and capsular stewardship reduce the risk of revision hip arthroscopy and conversion to total hip arthroplasty, inform sport-specific counseling, and align with joint-preservation goals in young, active patients.

Level of evidence: V (Narrative Review).

Purpose: To examine the health history, growth and maturation profiles, and current health status of youth triathletes prior to entry into a National Institute Network (NIN); and determine associations between growth, training load, and health problem severity to inform developmental training strategies.

Methods: Youth triathletes (ages 12-18) were monitored over one year. Data was collected on athletic health history, growth (height, weight, arm spam) and maturation (bone age (BA); peak height velocity (PHV), predicted adult height (PAH), PAH%). Over 10 weeks the Oslo Sports Trauma Research Centre questionnaire (OSTRC-H2 questionnaire), training load and rate of perceived exertion (RPE) were recorded across triathlon disciplines.

Results: Estimated PHV occurred later than population norms (Female 12.5 ± 0.7; Male 13.3 ± 0.6). Estimated BA exceeded chronological age (CA) in both sexes. Males showed higher height tempo (B = 0.09, PD = 0.85), and arm span tempo than females (B = 0.20, PD = 0.96). Higher maturity offset was associated with greater total health problem severity (B = 0.23, PD = 0.98), reflecting a 25% increase per 1-year in maturity offset, and males typically had higher total severity (B = 0.52, PD = 0.90). Illnesses (n = 22) exceeded injuries (n = 14) and resulted in more total time-loss (3 vs 2 weeks). Swimming had the highest training volume, 24% higher than the bike (B = -0.28, PD = 0.99) and 44% higher than the running (B = -0.58, PD = 1.00), although more lower limb injuries were reported.

Conclusion: Sex-based maturation differences in youth triathletes require tailored training; high illness and injury prevalence identify the need for growth monitoring and balanced training to support long term athlete performance progression.

Knee osteoarthritis (OA) is a common degenerative joint disease affecting approximately 22% of adults over the age of 40 and is a major contributor to pain and disability worldwide. Platelet-rich plasma (PRP) has gained attention as a biologic treatment for this pathology due to its potential in modulating inflammation. This narrative review evaluates the current evidence on PRP for knee OA, comparing its efficacy to hyaluronic acid (HA), corticosteroids, and bone marrow aspirate concentrate (BMAC). High-quality studies consistently demonstrate that PRP provides superior pain relief and functional improvement compared to HA and corticosteroids and offers comparable results to BMAC. PRP is effective across all Kellgren-Lawrence grades, with the greatest benefits seen in early to moderate OA. Three-injection regimens appear more effective than single injections, and while both leukocyte-rich and leukocyte-poor formulations are used, no clear consensus exists on which is superior. Despite promising short- and mid-term outcomes, variability in preparation methods and limited long-term evidence remain important limitations. Current literature suggests that PRP may be a safe and potentially effective nonoperative option for managing knee osteoarthritis, though further high-quality, standardized studies are needed to confirm its long-term efficacy and optimal application.

Exercise-associated hyponatremia (EAH) is an important cause of preventable morbidity and mortality. EAH refers to a low blood sodium concentration [Na⁺] of <135 mmol·L^-1, during or within 24 h of sustained endurance exercise. The current EAH literature contains ambiguities among field studies and unresolved clinical issues. Seeking clarity and resolution, we conducted manual searches of two large electronic databases using pre-defined inclusion criteria and discovered 1516 article titles and abstracts. Subsequent reviews of 345 full-length articles identified 56 eligible field research studies that reported 220 EAH cases during seven outdoor endurance activities (5-29.5 h duration). Our evaluations of these EAH cases generated the following seven findings. First, a greater percentage, not the absolute number, of women experienced EAH than men. Second, event specificity may account for much of the wide range of EAH symptoms and signs (SAS) reported among different outdoor activities. Third, out of 220 reported cases of EAH, none were asymptomatic when [Na⁺] was <130 mmol·L^-1. Fourth, the absolute value of [Na⁺] is not a reliable predictive index of EAH clinical severity or presentation. Fifth, running or hiking resulted in far more EAH cases and published epidemiological studies than cycling, swimming, and triathlon events. Sixth, the most common mild EAH complaints were nausea, weakness or lethargy, dizziness, headache, and extremity swelling. Seventh, the most common SAS of moderate-to-severe EAH (ie, suggesting hyponatremic encephalopathy) included altered mental status, vomiting, seizure, agitation/restlessness, collapse, and loss of consciousness. In conclusion, these findings should inform pre-event medical planning, on-site medical staff briefings, as well as the diagnosis of EAH severity in field settings. We also propose that our inventory of position statements and consensus documents will meet the needs of athletes and coaches who seek dependable information regarding risk factors and prevention.

Introduction: Bone mineral density (BMD) from dual-energy x-ray absorptiometry (DXA) provides bone health information. BMD monitoring in collegiate athletes may be beneficial for performance and overall bone health. Currently, there is limited information regarding BMD among female Division I athletes, with no studies tracking pre- to postseason dominant and non-dominant limb BMD in this demographic. The purpose of this study was to assess changes in lower limb BMD in this population from pre- to postseason.

Methods: Sixty-four participants (field hockey, soccer, and volleyball) were included in this analysis. Preseason DXA scans were completed before the start of the athletic season and postseason was on average collected 126.5 ± 13.4 days after. A full-body DXA scan was completed, and dominant and non-dominant lower limb BMD values were utilized in the statistical analysis. A 2×2 ANCOVA was conducted with sport type set as a covariate.

Results: Preseason (age: 20.4±1.56 years, height: 168.0±7.2 cm, weight: 66.0±9.4 kg) lower limb BMD was not significantly different from postseason. The interaction between time and limb (F₁,₆₁=0.09, p=0.76) was not significant. No significant main effects were seen for time (F₁,₆₁ =0.80, p=0.38). There was a significant main effect for limb (F₁,₆₁=4.45, p=0.04).

Conclusion: No significant changes were seen in lower limb BMD from pre- to postseason in female athletes, a significant difference was observed between the dominant and non-dominant limb. BMD monitoring is important to preserve bone health and future research should explore BMD changes over multiple seasons to assess potential sport-specific or cumulative effects.

Rotator cuff pathology is present in nearly half the adult population over the age of 50 years and remains a leading cause of shoulder pain and dysfunction. These musculotendinous injuries may be the result of an acute trauma or chronic degeneration. Clinical examination involves inspection, range of motion, and strength assessment with special testing used to isolate the involved rotator cuff muscles. The classification of these injuries involves identification of tear size, thickness, morphology, and the presence of tendon retraction or muscular atrophy to guide clinical management. Magnetic resonance imaging is the primary imaging modality used to define these metrics unless contraindicated in select patients. Nonoperative management is largely reserved for partial thickness tears involving <1 cm full thickness tears. Surgical repair is indicated in the symptomatic patient with >25% of bursal or >50% articular surface involvement and those >1 cm in the sagittal plane. These are often managed with primary repair using single row, double row or transosseous equivalent techniques. In the event of irreparable rotator cuff tears with significant tendon retraction with or without fatty atrophy, partial repair techniques with augmentation, superior capsular reconstruction, and balloon spacers remain salvage options prior to consideration of reverse shoulder arthroplasty. Additionally, there remains debate on optimal postoperative rehabilitation protocol with recent literature supporting early passive mobilization and active range of motion at four to six weeks without compromise of tendon repair integrity that could serve to optimize both glenohumeral motion, accelerated recovery and strength optimization without an increase in re-tear rates. There is currently a lack of high-quality, long-term studies directly comparing surgical techniques and nonsurgical management, especially with follow-up beyond five years to assess durability, re-tear rates, and functional outcomes. This review aims to critically appraise the available evidence to guide optimal rotator cuff repair techniques and postoperative rehabilitation protocols.

Knee dislocations (KD) and multiligamentous knee injuries (MLKI) are challenging injuries to manage due to the high incidence of associated neurovascular compromise, extensive peri-articular soft-tissue trauma, and long-term functional deficits. Knee-spanning external fixation (KSEF) is occasionally utilized in the acute management of these injuries with the aim of maintaining alignment, protecting vascular repairs, allowing soft-tissue recovery prior to definitive treatment, and protecting freshly reconstructed or repaired ligaments. Despite its use in 5% of MLKIs and up to 50% of KDs, the clinical indications, outcomes, and complications associated with KSEF in the setting of KD/MLKI remain incompletely defined. Furthermore, KD/MLKI treatment algorithms incorporating decision-making related to KSEF application are limited both institutionally and within the literature. Thus, the purpose of this study was to consolidate the existing evidence related to the use of KSEF in the setting of KD/MLKI to support clinical decision-making and identify avenues for future investigation. Following a narrative review of the literature, the identified indications for KSEF in the setting of KD/MLKI were vascular injury, knee fracture-dislocation, extensive soft-tissue injury, persistent instability following reduction, open KDs, and when bracing is not feasible due to patient factors such as morbid obesity. Both rigid and hinged KSEF constructs have been described, with hinged fixators potentially permitting early motion while providing joint stability. Reported complications of KSEF include arthrofibrosis, infection, heterotopic ossification, and compartment syndrome, though available data are primarily retrospective and heterogeneous. Other topics that have been addressed in the literature include biomechanics, cost, magnetic resonance imaging (MRI) compatibility, and psychological impact. However, further research is needed to clarify its specific role, define standardized indications, and compare outcomes with non-invasive or alternative fixation and immobilization strategies.

Background: Although exercises and physical activities are beneficial for overall health, it can unfortunately result in a musculoskeletal injury that requires a surgical intervention in physically active youth. One of the major injures young athletes sustain is anterior cruciate ligament (ACL) tear, which often requires a surgical intervention. Following the ACL reconstruction (ACLR) surgery, athletes need to participate in rehabilitation and often perform return-to-sport (RTS) testing. During this process, the RTS decision requires the contributions of multidisciplinary sports medicine healthcare providers.

Purpose: To discuss how to optimize a safe RTS from the perspective of multidisciplinary sports medicine healthcare practitioners and synthesize them with research-based evidence using a clinical scenario involving a female athlete following ACL injury.

Methods: A clinical scenario of a young female basketball player with an ACL tear is presented. In this particular case, the patient had a previous ACL tear history in her contralateral limb. Thigh circumference, knee range of motion, quadriceps and hamstrings strength, hop tests, and psychological readiness measures at 9 months post-operatively is also presented.

Results: An orthopaedic surgeon, academic-physiotherapist, sports psychiatrist, clinical physical therapy, and performance and sport scientist provided their RTS perspectives based on the given scenario. Because of her previous history and low psychological readiness, several emerging concepts were discussed including neurocognitive-based rehabilitation, cognitive-behavioral therapy, and step-by-step RTS progression (return to participation, sport, and performance).

Conclusion: The current article synthesized clinical insights from various sports medicine healthcare with practitioners and research evidence based on an ACL clinical scenario. The approaches discussed in this paper may be beneficial to facilitate safe RTS.

Background: Blood lactate (BL) is a critical biomarker for assessing anaerobic metabolism and fatigue. Sweat lactate (SWL) and sweat rate (SWR) have been explored as non-invasive alternatives, but their capacity to estimate BL dynamics after short-term high-intensity exercise remains unclear.

Purpose: This pilot study aimed to evaluate whether BL dynamics can be predicted using a regression model based on the time-series patterns of SWL and SWR measured by wearable sensors.

Methods: Five healthy male athletes (three sprinters and two endurance runners) performed a 30-second Wingate anaerobic test. SWL and SWR were continuously monitored using a wearable electrochemical sensor and a ventilated capsule-type sweat rate meter. Capillary BL was sampled for 30 minutes post-exercise.

Results: BL showed a delayed peak at 6.4 ± 1.2 min, while SWL and SWR exhibited biphasic responses. The second SWL peak (7.5 ± 2.2 min) aligned with the BL peak. Although peak-based correlations were not significant, Pearson correlations using time-series data revealed strong associations (r = 0.501-0.933 for SWL; r = 0.515-0.805 for SWR; all p < 0.001). A multivariate regression model using both variables predicted BL with high accuracy (R² = 0.763, RMSE = 1.612, MAE = 0.995, p < 0.001).

Conclusion: These findings support the feasibility of a regression-based approach using sweat-derived time-series data to non-invasively estimate BL dynamics after high-intensity exercise.

Background: In Japan, pitch count recommendations were proposed to prevent throwing injuries. In our laboratory, 10 years ago, the knowledge and compliance with pitch count recommendations were assessed among coaches in Kyoto Prefecture and compared with those in the US Since then, the youth baseball environment has changed, including the formal implementation of pitch count rules by the Japan Boys League Foundation. However, no studies have examined how such changes have influenced coaches' knowledge and compliance over time. Although it is important for coaches to have prior knowledge of injuries in order to prevent the incidence of Little League Elbow, few studies have assessed the actual experience of coaches.

Methods: Of the 242 coaches belonging to the Kyoto Boys' Baseball Association who participated, 172 with valid responses were analyzed. The questionnaire, consistent with a previous study conducted 10 years ago, assessed knowledge and compliance with pitch count recommendations, as well as coaching background and seminar participation.

Results: The proportion of coaches who reported having knowledge of the recommendations significantly increased from 39.8% to 52.3% (p = 0.04), while the compliance rate decreased from 28.3% to 22.1% (p = 0.23). Coaches with knowledge tended to be older and have longer coaching experience, while those who complied were significantly younger and less experienced. Seminar participation was associated with increased knowledge but did not result in higher compliance. Moreover, 70% of coaches were also parents of players; these individuals were younger, had less coaching experience, and were less likely to have attended seminars.

Conclusion: Despite increased knowledge among youth baseball coaches, compliance with pitch count recommendations remains limited. This knowledge-behavior gap suggests the need for educational interventions that address not only the dissemination of information but also cultural and psychological barriers to behavior change. Tailored support may be especially beneficial for younger and less experienced coaches.