Non-contact Injury Mechanisms Research Articles

Evaluation and Management of Glenohumeral Instability in Adolescent Patients: An Expert Consensus Statement.

Management of glenohumeral instability in the adolescent population can be both challenging and controversial. There are no current guidelines for optimal management of glenohumeral instability in this population (unidirectional or multidirectional), and the cutoff ages for transition to adult treatment are not known. To develop consensus-based guidelines for the management of glenohumeral instability in adolescents. Consensus statement. A 26-question, multiple-choice survey was developed after 2 rounds of iterations and was submitted to the orthopaedic surgeons of the Pediatric Research in Sports Medicine (PRiSM) Society. The survey comprised 3 sections-demographics, practice setting, and decision-making-and included cutoff ages and management in 5 specific case scenarios. Consensus-based guidelines were generated with 66% response agreement. An indication score was then applied to each response related to more aggressive management to determine if variables related to consensus (or lack thereof) could be identified. A total of 54 responses were returned. Of the respondents, 59% were from academic practice, 84% were pediatric orthopaedic fellowship trained, and 46% performed >25 shoulder instability cases per year. In the setting of first-time anterior shoulder dislocation, nonoperative treatment was preferred for boys aged <14 years and girls aged <13 years. Besides age, proximal humerus physeal status, injury mechanism, sport, and presence of bony injury affected treatment selection. The presence of a Bankart lesion was an indication for stabilization in first-time dislocations for contact athletes with a closing or closed physis, but not in patients with an open physis or noncontact injury mechanisms. For recurrent anterior shoulder dislocation, stabilization was preferred irrespective of physis status. Initial nonoperative treatment was preferred for multidirectional instability. In the setting of first-time anterior shoulder dislocation in patients with open physes, nonoperative treatment was preferred for boys <14 years and girls <13 years. Future multicenter prospective studies focusing on outcomes would help to validate current practice patterns, especially in scenarios for which no consensus was reached.

Investigating the Bone Bruise Patterns in Pediatric Patients With Contact and Noncontact Acute Anterior Cruciate Ligament Tears: A Multicenter Study

Background: In adults with anterior cruciate ligament (ACL) tears, bone bruises on magnetic resonance imaging (MRI) scans provide insight into the underlying mechanism of injury. There is a paucity of literature that has investigated these relationships in children with ACL tears. Purpose: To examine and compare the number and location of bone bruises between contact and noncontact ACL tears in pediatric patients. Study Design: Cohort study; Level of evidence, 3. Methods: Boys ≤14 years and girls ≤12 years of age who underwent primary ACL reconstruction surgery between 2018 and 2022 were identified at 3 separate institutions. Eligibility criteria required detailed documentation of the mechanism of injury and MRI performed within 30 days of the initial ACL tear. Patients with congenital lower extremity abnormalities, concomitant fractures, injuries to the posterolateral corner and/or posterior cruciate ligament, previous ipsilateral knee injuries or surgeries, or closed physes evident on MRI scans were excluded. Patients were stratified into 2 groups based on a contact or noncontact mechanism of injury. Preoperative MRI scans were retrospectively reviewed for the presence of bone bruises in the coronal and sagittal planes using fat-suppressed T2-weighted images and a grid-based mapping technique of the tibiofemoral joint. Results: A total of 109 patients were included, with 76 (69.7%) patients sustaining noncontact injuries and 33 (30.3%) patients sustaining contact injuries. There were no significant differences between the contact and noncontact groups in terms of age (11.8 ± 2.0 vs 12.4 ± 1.3 years; P = .12), male sex (90.9% vs 88.2%; P > .99), time from initial injury to MRI (10.3 ± 8.1 vs 10.4 ± 8.9 days; P = .84), the presence of a concomitant medial meniscus tear (18.2% vs 14.5%; P = .62) or lateral meniscus tear (69.7% vs 52.6%; P = .097), and sport-related injuries (82.9% vs 81.8%; P = .89). No significant differences were observed in the frequency of combined lateral tibiofemoral (lateral femoral condyle + lateral tibial plateau) bone bruises (87.9% contact vs 78.9% noncontact; P = .41) or combined medial tibiofemoral (medial femoral condyle [MFC] + medial tibial plateau) bone bruises (54.5% contact vs 35.5% noncontact; P = .064). Patients with contact ACL tears were significantly more likely to have centrally located MFC bruising (odds ratio, 4.3; 95% CI, 1.6-11; P = .0038) and less likely to have bruising on the anterior aspect of the lateral tibial plateau (odds ratio, 0.27; 95% CI, 0.097-0.76; P = .013). Conclusion: Children with contact ACL tears were 4 times more likely to present with centrally located MFC bone bruises on preoperative MRI scans compared with children who sustained noncontact ACL tears. Future studies should investigate the relationship between these bone bruise patterns and the potential risk of articular cartilage damage in pediatric patients with contact ACL tears.

Lateral Ankle Joint Injuries in Indoor and Court Sports: A Systematic Video Analysis of 445 Nonconsecutive Case Series

Background: Lateral ankle sprains are one of the most common injuries in indoor and court sports. Self-reports and case studies have indicated that these injuries occur via both contact and noncontact injury mechanisms typically because of excessive inversion in combination with plantarflexion and adduction of the foot. Video-based documentation of the injury mechanism exists, but the number of cases reported in the literature is limited. Purpose: To retrieve and systematically analyze a large number of video-recorded lateral ankle injuries from indoor and court sports, as well as describe the injury mechanism, injury motion, and injury pattern across different sports. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 445 unique video-recorded lateral ankle sprain injuries were retrieved from indoor and court sports of broadcasted levels of competition. The videos were independently analyzed by 2 different reviewers. Outcomes included classification of the injury mechanism according to the International Olympic Committee consensus guidelines, primary and secondary motions of ankle joint distortion, and documentation of the fixation point (fulcrum) around which the foot rotates. Results: Overall, 298 (67%) injuries were direct contact, 113 (25%) were noncontact, and 32 (7%) were indirect contact incidents. Direct contact injuries were especially prevalent in basketball (76%), handball (80%), and volleyball (85%), while noncontact injuries dominated in tennis and badminton (96% vs 95% across both). Inversion (65%) and internal rotation (33%) were the primary distortion motions, with the lateral forefoot (53%) and lateral midfoot (40%) serving as the main fulcrums. Landing on another player's foot was the leading cause of injury (n = 246; 55%), primarily characterized by inversion (79%) around a midfoot fulcrum (54%). The noncontact and indirect landings on floor (n = 144; 33%) were primarily characterized by a distortion around a forefoot fulcrum (69%). Conclusion: Two of 3 ankle sprains from online video platforms were direct contact injuries, with most involving landing on another player's foot. The distortion motion seems to be related to the injury mechanism and the fixation point between the foot and the floor. The injury mechanisms varied greatly between sports, and future studies should clearly differentiate and investigate the specific injury mechanisms.

Adjustable Cortical Fixation Repair Is a Safe and Effective Technique for Quadriceps Tendon Rupture

To report the clinical outcomes of quadriceps tendon repair using adjustable cortical fixation devices at a minimum 2-year follow-up. A retrospective chart review identified patients who underwent quadriceps tendon repair using adjustable cortical fixation devices between January 2017 and March 2020. Patients with a partial tendon rupture were excluded. Demographic and injury-specific variables were gathered preoperatively and postoperatively from the electronic medical record and patient-reported outcomes (Lysholm Knee Questionnaire, Lower Extremity Functional Scale, and SF-12) were collected via telephone at a minimum of 2 years postoperatively. Fourteen quadriceps tendon repairs were included in a total of 13 patients. The average time to follow-up was 3.5 ± 1.2 years with a range of 1.9 to 5.7 years. The mean age of this cohort was 55.7 ± 11.6 years, and the mean body mass index was 32.9 ± 6.0. Ten injuries (71.4%) were sustained by mechanical fall, 2 patients (14.3%) suffered a direct blow to the knee, and 2 patients (14.3%) reported a noncontact injury mechanism. Thirteen quadriceps ruptures (13/14, 92.9%) underwent surgery within 10 days of their injury. One knee (7.1%) had a postoperative extensor lag of 5°, whereas another knee (7.1%) required a reoperation for manipulation under anesthesia and arthroscopic lysis of adhesions at 3 months' postoperatively. None of the included patients (0.0%) developed a tendon re-rupture, venous thromboembolism, delayed wound healing, surgical-site infection, neuropraxia or nerve injury, hardware irritation, patella fracture, or heterotopic ossification. In this study, adjustable cortical fixation was a safe and effective surgical technique for quadriceps tendon repair, with adequate restoration of quadriceps function and a low rate of adverse events at 2 years postoperatively. Level IV, therapeutic case series.

Anterior cruciate ligament rupture and associated Segond fracture: Incidence and effect on associated ligamentous and meniscal injuries

IntroductionThe Segond fracture is an avulsion fracture of the lateral tibial plateau and is widely considered to be pathognomonic of anterior cruciate ligament (ACL) rupture. In addition to ACL rupture, Segond fractures have also been noted to be associated with significant intra-articular pathology such as meniscal injuries as well as extra-articular pathology such as collateral ligament injuries. This is likely due to the fact that the presence of a Segond fracture may represent increased rotatory instability. Whilst several studies have demonstrated the association of a Segond fracture with significant intra-articular pathology, there is a paucity of literature assessing if the combination of an ACL rupture and Segond fracture gives rise to higher rates of concomitant ligamentous and meniscal injuries. The primary objective of this study is to determine if patients with ACL ruptures associated with Segond fractures have higher rates of concomitant ligamentous and meniscal injury, when compared to patients with ACL ruptures without a Segond fracture. MethodsA retrospective review of all patients who underwent ACL reconstruction in a single institution between 2014 to 2018 was conducted. A review of the patients’ demographics, operative notes, and radiographs was performed. X-rays and MRI scans were double-read by a board-certified radiologist and Orthopaedic surgeon. ResultsA total of 414 subjects were included. The incidence of Segond fracture was 2.4%. The mean age was 24.7±7.4 (range 16 to 60) years and 26.7±7.6 (range 16 to 38) years in patients with and without Segond fractures respectively. 89.9% of patients suffered a non-contact mechanism of injury, with sports injuries being most common (79.5%). There was a significantly higher rate of isolated lateral meniscus tears in patients with Segond fractures compared to those without (50% v.s. 20.8%) based on pre-operative MRI. (p<0.05) There were no other significant differences in associated ligamentous injuries. ConclusionThe incidence of Segond fracture associated with ACL rupture is 2.4%. There is a significantly higher risk of a concomitant isolated lateral meniscus tear in ACL ruptures associated with a Segond fracture. There is no significantly higher risk of concomitant ligamentous injuries in ACL ruptures associated with a Segond fracture.

ERKEN CUMHURİYET DÖNEMİ TÜRKİYE’SİNDE FUTBOL YARALANMALARI: GAZETE KUPÜRLERİNİN BETİMSEL İÇERİK ANALİZİ

Amaç&#x0D; Çalışmanın amacı 1937-1938 Milli Küme Futbol sezonunda&#x0D; oynanan futbol müsabakalarında gerçekleşen&#x0D; futbol yaralanmalarını, dönemin gazete kupürlerinden&#x0D; faydalanarak tespit edip güncel spor hekimliği yaklaşımıyla&#x0D; içerik analizine tabi tutmaktır.&#x0D; Gereç ve Yöntem&#x0D; Çalışmada 1937-1938 futbol sezonundaki spor yaralanmalarını&#x0D; incelemek üzere dönemin gazetelerinden&#x0D; içerik analizinde kullanılacaklar belirlendi. Bu gazeteler&#x0D; www.gastearsivi.com web adresindeki dijital arşivden&#x0D; incelendi. Kapsamı bakımından etik kurul onayı&#x0D; gerektirmeyen çalışmada, gazete kupürlerinde konu&#x0D; edilen futbol yaralanmaları, futbolda yaralanma sınıflamasına&#x0D; göre kategorize edildi.&#x0D; Bulgular&#x0D; Sezon boyunca oynanan 48 maçta toplam 37 adet&#x0D; spor yaralanması tespit edilmiştir. Bu 37 yaralanma&#x0D; içinde, yaralanma tipine göre %38 (n=14) kontüzyon,&#x0D; %24 (n=9) strain veya sprain, %13 (n=5) konküzyon,&#x0D; %11 (n=4) laserasyon, %8 (n=3) yorgunluk, %3 (n=1)&#x0D; künt batın travması ve %3 (n=1) hastalık hadisesi;&#x0D; yaralanma bölgesine göre incelediğimizde ise %59&#x0D; (n=22) alt ekstremite, %24 (n=9) kafa, %11 (n=4) tüm&#x0D; vücut, %3 (n=1) üst ekstremite ve %3 (n=1) karın bölgesinde&#x0D; yaralanma olduğu gözlemlenmiştir. Bu yaralanmaların&#x0D; %64’ü kontakt (n=24), %36’sı (n=13) nonkontakt&#x0D; yaralanma mekanizmasıyla gerçekleşmiştir.&#x0D; Sonuç&#x0D; 1937-38 Milli Küme sezonunda futbol yaralanmalarına&#x0D; sıkça rastlanmıştır. Dönemin tıbbi ve sportif şartlarından&#x0D; dolayı tanı ve/veya tedavi yaklaşımları günümüzden&#x0D; farklı olsa da gazete kupürlerinden elde edilen&#x0D; bilgiler doğrultusunda döneme ait yorum yapılabilmesi&#x0D; değerlidir. Çalışmamızın bu sonuca uygun olarak&#x0D; gelecekte yapılacak benzer çalışmalara metodolojik&#x0D; olarak ışık tutacağına inanmaktayız.

Significantly Delayed Medium-Latency Response of the Stretch Reflex in Delayed-Onset Muscle Soreness of the Quadriceps Femoris Muscles Is Indicative of Sensory Neuronal Microdamage.

Unaccustomed or strenuous eccentric exercise is known to cause delayed-onset muscle soreness. A recent hypothesis postulated that mechano-energetic microinjury of the primary afferent sensory neuron terminals in the muscle spindles, namely a transient Piezo2 channelopathy, could be the critical cause of delayed-onset muscle soreness in the form of a bi-phasic non-contact injury mechanism. This theory includes that this microlesion could delay the medium-latency response of the stretch reflex. Our aim with this study was to investigate this hypothesis. According to our knowledge, no study has examined the effect of delayed-onset muscle soreness on the medium-latency response of the stretch reflex. Our findings demonstrated that a significant delay in the medium-latency stretch reflex could be observed right after a multi-stage fitness test in the quadriceps femoris muscles of Hungarian professional handball players who consequently experienced delayed-onset muscle soreness. The long-latency stretch reflex and most likely short-latency stretch reflex were unaffected by delayed-onset muscle soreness in our study, which is in line with earlier findings. We translate these findings as indicative of proprioceptive Type Ia terminal microdamage in the muscle spindle in line with the aforementioned new acute non-contact compression axonopathy theory of delayed-onset muscles soreness.

A Novel MRI Mapping Technique for Evaluating Bone Bruising Patterns Associated With Noncontact ACL Ruptures

Background:Bone bruise patterns in the knee can aid in understanding the mechanism of injury in anterior cruciate ligament (ACL) ruptures. There is no universally accepted magnetic resonance imaging (MRI) mapping technique to describe the specific locations of bone bruises.Hypothesis:The authors hypothesized that (1) our novel mapping technique would show high interrater and intrarater reliability for the location of bone bruises in noncontact ACL-injured knees and (2) the bone bruise patterns reported from this technique would support the most common mechanisms of noncontact ACL injury, including valgus stress, anterior tibial translation, and internal tibial rotation.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Included were 43 patients who underwent ACL reconstruction between 2018 and 2020, with MRI within 30 days of the injury on a 3.0-T scanner, documentation of a noncontact mechanism of injury, and no concomitant or previous knee injuries. Images were retrospectively reviewed by 2 radiologists blinded to all clinical data. The locations of bone bruises were mapped on fat-suppressed T2-weighted coronal and sagittal images using a novel technique that combined the International Cartilage Repair Society (ICRS) tibiofemoral articular cartilage surgical lesions diagram and the Whole-Organ Magnetic Resonance Imaging Scoring (WORMS) mapping system. Reliability between the reviewers was assessed using the intraclass correlation coefficient (ICC), where ICC >0.90 indicated excellent agreement.Results:The interrater and intrarater ICCs were 0.918 and 0.974, respectively, for femoral edema mapping and 0.979 and 0.978, respectively, for tibial edema mapping. Significantly more bone bruises were seen within the lateral femoral condyle compared with the medial femoral condyle (67% vs 33%; P < .0001), and more bruises were seen within the lateral tibial plateau compared with the medial tibial plateau (65% vs 35%; P < .0001). Femoral bruises were almost exclusively located in the anterior/central regions (98%) of the condyles as opposed to the posterior region (2%; P < .0001). Tibial bruises were localized to the posterior region (78%) of both plateaus as opposed to the anterior/central regions (22%; P < .0001).Conclusion:The combined mapping technique offered a standardized and reliable method for reporting bone bruises in noncontact ACL injuries. The contusion patterns identified using this technique were indicative of the most commonly reported mechanisms for noncontact ACL injuries.

Amyotrophic lateral sclerosis and delayed onset muscle soreness in light of the impaired blink and stretch reflexes - watch out for Piezo2.

Amyotrophic lateral sclerosis (ALS) is a fatal, multisystem neurodegenerative disease that causes the death of motoneurons (MNs) progressively and eventually leads to paralysis. In contrast, delayed onset muscle soreness (DOMS) is defined as delayed onset soreness, muscle stiffness, loss of force-generating capacity, reduced joint range of motion, and decreased proprioceptive function. Sensory deficits and impaired proprioception are common symptoms of both ALS and DOMS, as impairment at the proprioceptive sensory terminals in the muscle spindle is theorized to occur in both. The important clinical distinction is that extraocular muscles (EOM) are relatively spared in ALS, in contrast to limb skeletal muscles; however, the blink reflex goes through a gradual impairment in a later stage of disease progression. Noteworthy is, that, the stretch of EOM induces the blink reflex. The current authors suggest that the impairment of proprioceptive sensory nerve terminals in the EOM muscle spindles are partially responsible for lower blink reflex, beyond central origin, and implies the critical role of Piezo2 ion channels and Wnt-PIP2 signaling in this pathomechanism. The proposed microinjury of Piezo2 on muscle spindle proprioceptive terminals could provide an explanation for the painless dying-back noncontact injury mechanism theory of ALS.

Injuries in elite-level women's football-a two-year prospective study in the Irish Women's National League.

We investigated the pattern of injuries in elite-level women's football in Ireland, during a two-season prospective injury surveillance study in the Women's National League (WNL). Seven out of the eight clubs (271 players) in the WNL were followed prospectively during the 2018 and 2019 seasons. The injury incidence rate in matches (19.2/1000h) was 7.5times higher than in training (2.5/1000h). Players, on average, sustained 0.69injuries per season (266injuries/383player seasons), which equates to 15time-loss injuries per season for a squad of 22players. The majority of the injuries sustained by players were lower extremity injuries (85%), of which, 46% had a non-contact injury mechanism. Muscle, ligament, and contusion injuries were the most common injury types, while the ankle, knee, and thigh were the most commonly injured body sites. The most common injuries sustained over the two seasons were lateral ankle sprains (13.9%), hamstring strains (12.4%), knee meniscus/cartilage injuries (7.5%), adductor strains (6%), quadriceps strains (4.5%), and ankle contusions (4.5%). The injuries with the highest injury burden were ACL injuries (59days lost/1000h), knee meniscus/cartilage injuries (23/1000h), lateral ankle sprains (21/1000h), hamstring strains (12/1000h), MCL sprains (11/1000h), and quadriceps strains (11/1000h). There were 8 ACL tears documented over the 2seasons, which accounted for 28% of all time lost to injury with a mean days lost per injury of 247. We recommend that clubs in the WNL in Ireland should implement injury risk mitigation strategies, with a particular focus on injuries with a high injury burden.

ANTERIOR CRUCIATE LIGAMENT TEAR FOLLOWING SURGICAL TREATMENT OF PEDIATRIC TIBIAL EMINENCE FRACTURE IN A MULTICENTER COHORT

Background:While operative treatment of displaced pediatric tibial eminence fractures has generally been shown to be safe, post-operative complications including arthrofibrosis, infection, fixation failure, and postoperative ipsilateral ACL injuries remain prevalent. The purpose of this study was to describe the prevalence of and risk factors for post-operative ACL tears in a cohort of patients surgically treated for tibial eminence fracture.Methods:We performed a retrospective review of children undergoing treatment of a tibial eminence fracture at 10 tertiary children’s hospitals.. The primary outcome was subsequent ACL rupture. Patients with 2 year follow up data and those that had met the primary outcome within the 2 year period, were analyzed for demographics, risk factors and survival analysesResults:385 pediatric patients were reviewed. Overall, 46 patients had either 2 year follow up data or met the primary outcome measure of an ACL tear prior to the 2 year mark. Mean age was 11.2 years old (SD 2.8), and the median follow time was 36.4 months (SD 17.7 months) There was a 21.7% incidence of subsequent ACL tear in the cohort analyzed. Subsequent ACL tears occurred at a median of 10.2 months (SD 19.5 months) postoperatively. There was a statistically significant association with higher Myers & McKeever grade tibial spine fractures (Type III and IV) and subsequent ACL rupture (p=0.006). Subsequent ACL tears occurred in patients who were older when they had their original tibial eminence fracture, 13.4 years old versus 11.3 years old (p=0.035). There was no statistically significant relationship between ipsilateral ACL tear and body mass index, operative time, fixation method used, postoperative weight bearing status, type of postoperative immobilization, contact versus non-contact injury mechanism, type of post-operative physical therapy protocol based on chi-squared or t-test (p>0.05).Conclusion:Subsequent ipsilateral ACL tears following operatively treated pediatric tibial eminence fractures in a large multicenter cohort occurred at a rate of 21.7%. They were associated with completely displaced (Type III or IV) tibial eminence fractures, and older patients. Clinicians should therefore continue to follow patients for at least 2 years after treatment of pediatric tibial eminence fractures in order to track this potential complication.

Steep posterior lateral tibial slope, bone contusion on lateral compartments and combined medial collateral ligament injury are associated with the increased risk of lateral meniscal tear.

To determine the risk factors for lateral meniscus and root tears in patients with acute anterior cruciate ligament (ACL) injuries. A total of 226 patients undergoing acute ACL reconstruction were included in the study sample. Exclusion criteria were revisions, fractures, chronic cases, and multiple ligament injuries, with the exception of medial collateral ligament (MCL) injuries. The patients were divided into groups based on the presence of lateral meniscus and root tears by arthroscopy. Binary logistic regression was used to analyze risk factors including age, sex, body mass index (BMI), injury mechanism (contact/non-contact), Segond fracture, side-to-side laxity, location of bone contusion, medial and lateral tibial and meniscal slope, mechanical axis angle, and grade of pivot shift. Overall lateral meniscus (LM) tears were identified in 97 patients (42.9%), and LM root tears were found in 22 patients (9.7%). The risk of an LM tear in ACL-injured knees increased with bone contusion on LTP (odds ratio [OR], 3.5; 95% confidence interval [CI] 1.419-8.634; P = 0.007), steeper lateral tibial slope (OR, 1.133; 95% CI 1.003-1.28; P = 0.045), MCL injury (OR, 2.618; 95% CI 1.444-4.746; P = 0.002), and non-contact injury mechanism (OR, 3.132; 95% CI 1.446-6.785; P = 0.004) in logistic regression analysis. The risk of LM root tear in ACL-injured knees increased with high-grade pivot shift (OR, 9.127; 95% CI 2.821-29.525; P = 0.000) and steeper lateral tibial slope (OR, 1.293; 95% CI 1.061-1.576; P = 0.011). The increased risk of LM lesions in acute ACL-injured knees should be considered if significant risk factors including bone contusion on lateral compartments, MCL injury, and a steeper lateral tibial slope are present. Moreover, high-grade rotational injury with steeper lateral tibial slope are also significant risk factors for LM root tears, and therefore care should be taken by clinicians not to miss such lesions. III.

Risk modelling further implicates the angiogenesis pathway in anterior cruciate ligament ruptures

ABSTRACT The aim of this study was to explore the interactions between the interleukins and the angiogenesis signalling pathway, following a pathway-based approach. Statistical modelling tools were used to develop a preliminary polygenic risk assessment model for anterior cruciate ligament (ACL) ruptures, incorporating the angiogenesis signalling genes (VEGFA and KDR) and interleukins (IL1B, IL6, IL6R) which also function to regulate angiogenesis. Multivariate logistic regression analysis was used to identify the most informative contributors to ACL rupture risk from a range of eleven potential intrinsic risk factors: age, sex, BMI and eight genetic polymorphisms within five genes, namely, IL1B rs16944 C/T, IL6 rs1800795 G/C, IL6R rs2228145 C/A, VEGFA rs699947 C/A, VEGFA rs1570360 G/A, VEGFA rs2010963 C/G, KDR rs2071559 A/G and KDR rs1870377 T/A. A total of 232 asymptomatic controls (CON) and 234 participants with surgically diagnosed ACL ruptures, of which 135 participants reported a non-contact mechanism of injury (NON subgroup), were previously genotyped for the selected polymorphisms. The polygenic risk model identified the VEGFA rs699947 CC genotype (p = 0.024, odds ratio (OR): 3.35, 95% confidence interval (CI): 1.17–9.62), VEGFA rs2010963 GC genotype (p = 0.049, OR: 2.43, 95% CI: 1.00–5.87), age (p = 0.011, OR: 0.97, 95% CI: 0.95–0.99) and BMI (p = 0.009, OR:1.09, 95% CI: 0.57–2.11) as the most significant predictors of ACL rupture risk from the data included. The results of this study highlight VEGFA, age and BMI as biologically significant components of this network requiring further investigation in the context of musculoskeletal soft tissue injury risk. Highlights The findings of this study highlight the VEGFA gene, age and BMI as biologically significant contributors to ACL rupture susceptibility. Upon further validation of these risk factors, they may be included in genetic risk assessment tools to design pre-habilitation strategies, prescribe appropriate treatment strategies after injury or to assess how an individual is likely to respond to load. Polygenic risk models aid in highlighting the components of the complex ECM remodelling pathway requiring further investigation, using a multidisciplinary approach. VEGFA is a key angiogenic protein contributing to ECM homeostasis and may therefore have potential therapeutic implications that need to be explored.

FUNCTIONAL MEASURES DO NOT DIFFER IN LATE STAGE REHABILITATION AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION ACCORDING TO MECHANISM OF INJURY.

Anterior cruciate ligament injuries are among the most common knee injuries. Mechanism of injury is classified as contact or non-contact. The majority of anterior cruciate ligament ruptures occur through a non-contact mechanism of injury. Non-contact anterior cruciate ligament ruptures are associated with biomechanical and neuromuscular risk factors that can predispose athletes to injuries and may impact future function. Non-contact mechanism of injury may be preceded by poor dynamic knee stability and therefore those with a non-contact mechanism of injury may be prone to poor dynamic knee stability post-operatively. Understanding how mechanism of injury affects post-operative functional recovery may have clinical implications on rehabilitation. The purpose of this study was to determine if mechanism of injury influenced strength, functional performance, patient-reported outcome measures, and psychological outlook in athletes at four time points in the first two years following anterior cruciate ligament reconstruction. Secondary analysis of a clinical trial. Seventy-nine athletes underwent functional testing at enrollment after impairment resolution. Quadriceps strength, hop testing, and patient-reported outcome measures were evaluated post-operatively at enrollment, following return-to-sport training and one year and two years after anterior cruciate ligament reconstruction. Participants were dichotomized by mechanism of injury (29 contact, 50 noncontact). Independent t-tests were used to compare differences between groups. There were no meaningful differences between contact and non-contact mechanism of injury in any variables at enrollment, post-training, one year, or two years after anterior cruciate ligament reconstruction. Function did not differ according to mechanism of injury during late stage rehabilitation or one or two years after anterior cruciate ligament reconstruction. III.

Similar Biomechanics During Change Of Direction In Adolescents With Contact Versus Non-contact Acl Injury

PURPOSE: Patients who sustain non-contact (N-CON) anterior cruciate ligament (ACL) injuries may be predisposed to injury due to deficient biomechanics. In contrast, patients who sustain contact (CON) ACL injuries may be injured due to unlucky trauma rather than poor biomechanics. This study compared biomechanics during change of direction movements between patients with CON vs. N-CON ACL injury mechanisms. We hypothesized that patients with CON ACL injury would have better biomechanics (greater shock absorption and less dynamic limb valgus) than patients with N-CON ACL injury. METHODS: 15 patients age 10-18 years with CON ACL injury (4 female; mean age 15.5, SD 2.1) and 94 with N-CON ACL injury (11 female; mean age 15.6, SD 1.9) underwent motion analysis 6-12 months (mean 7.5, SD 1.3) after ACL reconstruction (ACLR). Subjects performed forward-backwards and lateral change of direction tasks. 3D kinematic and kinetic variables reflecting dynamic limb valgus (frontal and transverse plane) and shock absorption (sagittal plane) were compared between patients who had CON and N-CON injury mechanisms using 2-tailed t-tests. RESULTS: No significant differences were observed between the CON and N-CON groups (Table). CONCLUSION: The CON injury group did not have better biomechanics than the N-CON group. This may be due to both groups engaging in similar rehabilitation programs. Alternatively, the CON injury group may have had similar pre-injury biomechanics to the N-CON group but happened to suffer a contact injury. These results suggest that all patients post-ACLR have potentially modifiable risk factors for re-injury and should have their biomechanics evaluated so any deficiencies can be rectified prior to return to sport regardless of injury mechanism.Table: Comparison of kinematics and kinetics between contact and non-contact ACL injury groupsExternal moments are reported. Angles are expressed in degrees, moments in N/kg, energy absorption in J/kg.

Do localization and appeareance of bone bruise influence the subjective short-term outcome after ACL reconstruction?

Aims and Objectives:Large external forces in anterior cruciate ligament (ACL) injury mechanisms cause a traumatic impact between femur and tibia. Apart from concomitant intraarticular injuries like meniscal tears and chondral lesions, MRI shows a high prevalence of femorotibial bone bruise (BB) without the arthroscopic proof of macroscopic chondral defects. In recent literature, controversial results are described concerning the association between BB and subjective outcome after ACL injury. There is very limited data for the results following ACL reconstruction.Aim of this study is the evaluation of the influence of localization and appeareance of BB in isolated ACL injuries on the subjective outcome of ACL reconstruction within the first year after surgery.Materials and Methods:This study is an analysis of preoperative MRI and prospectively collected subjective functional scores in 55 patients (sex m:f = 38:17; age 33,71±11,46 years; BMI 26,08±3,44) with isolated ACL injuries without concomitant intraarticular pathologies. These patients were treated between 09/15 and 11/17 by arthroscopic ACL reconstruction with ipsilateral hamstrings.MRI evaluation was performed blinded and independently by a radiologist and a surgeon.BB was diffentiated by 8 localizations: medial/lateral femoral condyle und tibial plateau, anteriorly and posteriorly each (MFA, MFP, LFA, LFP, MTA, MTP, LTA, LTP). Classification of appeareance was done according to Costa-Paz et al. (type I-III). Demographic data and injury mechanisms were collected.Finally, localization and appeareance of BB were analyzed statistically with regard to an impact on subjective functional outcome measures - Lysholm Score (LS) and Tegner Activitiy Scale (TAS) - before surgery (t0) and at four follow-up examinations (t1-t4 within one year after ACL reconstruction.Results:The time between injury and MRI was 35,09±94,52 days, between injury and surgery 96,09±120,75 days.In 80% (n=44) non-contact injury mechanisms could be detected, sports injuries in most cases (60%).BB was found in 94,4% (n=51), the most frequent localizations were LTP (74,5%, n=41) and LFA (56,4%, n=31). A singular femoral BB could not be found.Concerning the appeareance, distribution was shown as followed: n=18 (32,7%) type I, n=26 (47,3%) type II, n=7 (12,7%) type III. In n=6 MRI revealed a depression of the lateral femoral condyle (“lateral femoral notch sign”).For the whole cohort (independently from BB) we could demonstrate a highly significant improvement for LS and TAS over time (t0/t1-t4; ANOVA, p<0,001).Neither localization nor appeareance of BB had a significant impact on LS or TAS for t0-t4.Conclusion:In conclusion, the results of the existing literature for incidence and distribution of BB in ACL injuries are confirmed. Our own data showed no influence of BB on the subjective short-term outcome following ACL reconstruction within the first year after surgery.Further studies with longer follow-up period (>2 years) and volumetric BB measurement are in preparation.

SEX-SPECIFIC ENERGY ABSORPTION STRATEGIES DURING UNANTICIPATED SINGLE-LEG LANDINGS IN ADOLESCENTS: IMPLICATIONS FOR KNEE INJURIES

Background:The vast majority of ACL injuries in adolescents occur during non-contact injuries, in particular single-leg landings. The magnitude of energy absorption about each joint during theses landings influences the internal and external forces acting on the joints of the lower extremity. Understanding the biomechanics of landing in adolescent male and female athletes may provide insight into these non-contact injury mechanisms.Hypothesis/Purpose:This study set out to identify sex-specific energy absorption strategies during single-leg landing and determine the relationship between joint strength and the observed strategies. To better represent real-world conditions, we developed a novel unanticipated drop-jump landing protocol for this population.Methods:Thirty-one healthy youth athletes completed unanticipated single-leg drop-jump landings on their dominant limb. Kinematics and lower-limb contributions to energy absorption were calculated over the landing phase for each jump. Independent t-tests as well as Mann-Whitney U tests determined the presence of statistical differences between sexes. Pearson and Spearman correlation coefficients determined the relationship between isometric joint strength and the observed kinematics and energy absorption.Results:Females participants absorbed a larger proportion of the landing forces at the ankle and smaller proportion at the hip compared to males. Females also reached larger peak negative joint power in their knee and ankle. Both hip extension and ankle plantar flexion strength were correlated with greater spine flexion and less pelvic flexion.Conclusion:Females adopted an energy absorption strategy which utilized distal joints to absorb a larger portion of the landing forces and tended to absorb the forces later relative to males. A greater reliance on the distal joints is related to reduced hip strength and may increase the risk for sustaining an ACL injury.

Prevalence of knee injuries among male college students in Riyadh, Kingdom of Saudi Arabia

BackgroundThe knee is considered the most common injured joint between young sport participants. However, there is lack of proper prevalence estimation in our population.The purpose of this study was to identify the prevalence of knee injuries among male college students and to observe the demographic data associated with it. Our secondary objective was to evaluate the awareness and knowledge about these injuries.MethodsThis is a cross-sectional study. A survey was distributed to collect the data among male college students, King Saud University, Riyadh, Saudi Arabia. Out of 688 students who participated and completed the questionnaire, a total of 482 were considered valid and met the inclusion criteria. Data were analyzed using Statistical Package for Social Sciences (SPSS).ResultsThe overall prevalence of knee injury was 23.2% (n = 112). Most of them injured during sport activities especially soccer and 68.7% involved in a non-contact mechanism of injury. Among those who went to a hospital mostly were diagnosed as contusion (31.4%) then as meniscus tear, ACL, and collateral ligament injury, respectively. Majority was treated conservatively and only 10.7% needed surgery surprisingly. There was no statistically significant difference between those who are injured and whether they were warmed up and stretched or not (P = 0.619). Low level of knowledge about knee injuries was noticed among the participants 57.7%.ConclusionOur study has highlighted the high prevalence of knee injuries and the need to raise the level of awareness and knowledge about these injuries in our population. Soccer was the most common sport associated with knee injuries; most of these injuries were treated conservatively.

Exploring new genetic variants within COL5A1 intron 4-exon 5 region and TGF-β family with risk of anterior cruciate ligament ruptures.

Variants within genes encoding structural and regulatory elements of ligaments have been associated with musculoskeletal soft tissue injury risk. The role of intron 4-exon 5 variants within the α1 chain of type V collagen (COL5A1) gene and genes of the transforming growth factor-β (TGF-β) family, TGFBR3 and TGFBI, was investigated on the risk of anterior cruciate ligament (ACL) ruptures. A case-control genetic association study was performed on 210 control (CON) and 249 participants with surgically diagnosed ruptures (ACL), of which 147 reported a noncontact mechanism of injury (NON). Whole-exome sequencing data were used to prioritize variants of potential functional relevance. Genotyping for COL5A1 (rs3922912 G>A, rs4841926 C>T, and rs3124299 C>T), TGFBR3 (rs1805113 G>A and rs1805117 T>C), and TGFBI (rs1442 G>C) was performed using Taqman SNP genotyping assays. Significant overrepresentation of the G allele of TGFBR3 rs1805113 was observed in CON vs ACL (P = .014) and NON groups (P = .021). Similar results were obtained in a female with the G allele (CON vs ACL: P = .029; CON vs NON: P = .016). The TGFBI rs1442 CC genotype was overrepresented in the female ACL vs CON (P = .013). Associations of inferred allele combinations were observed in line with the above results. COL5A1 intron 4-exon 5 genomic interval was not associated with the risk of ACL ruptures. Instead, this novel study is the first to use this approach to identify variants within the TGF-β signaling pathway to be implicated in the risk of ACL ruptures. A genetic susceptibility interval was identified to be explored in the context of extracellular matrix remodeling.

MRI comparison of injury mechanism and anatomical factors between sexes in non-contact anterior cruciate ligament injuries.

Non-contact anterior cruciate ligament (ACL) rupture is mostly caused by a pivot shift mechanism including valgus collapse and internal tibial rotation. In female athletes, the incidence of ACL rupture has been reported to be significantly higher than in their male counterparts. However, to date, there have been limited reports and controversy regarding sex differences underlying injury mechanisms of ACL and severity of injury. In this study, we hypothesized that 1) in patients with non-contact ACL rupture, the incidence and severity of pivot shift injury, which are determined by injury pattern on MRI, would be significantly higher in females, and 2) anatomical factors associated with pivot shift injury would be significantly associated with female sex. A total of 148 primary ACL ruptures (145 patients) caused by non-contact injury mechanisms were included in this study. Among them, 41 knees (41 patients) were female and 107 knees (104 patients) were male. The status of the osseous lesions, lateral and medial tibial slope, depth of the medial tibial plateau, collateral ligaments, and menisci were assessed by MRI and compared between sexes. The severity of osseous lesions at the lateral tibial plateau, lateral femoral condyle, medial tibial plateau, and medial femoral condyle were comparable between sexes. There were no significant differences between sexes in the location of tibial contusions (p = 0.21), femoral contusions (p = 0.23), or meniscus tears (p = 0.189). Lateral tibial slope was found to be significantly larger in females (8.95° vs. 6.82°; p<0.0001; odds ratio = 1.464), and medial tibial depth was significantly shallower in females (1.80mm vs. 2.41mm; p<0.0001; odds ratio = 0.145). In conclusion, females showed greater lateral tibial slope and shallower medial tibial depth compared to males, however it did not affect the sex differences in injury pattern.