Health-related Outcomes after a Youth Sport–related Knee Injury

Assessing the efficacy of the Stop OsteoARthritis (SOAR) program: A randomized delayed-controlled trial in persons at increased risk of early onset post-traumatic knee osteoarthritis

OBJECTIVE

Assess the efficacy of an 8-week virtual, physiotherapist (PT)-guided knee health program (Stop OsteoARthritis (SOAR)) to improve knee extensor strength in individuals at risk of post-traumatic knee osteoarthritis (PTOA).

METHOD

In this superiority, randomized delayed-control trial, persons aged 16-35 years, 1-4 years after a self-reported knee joint injury were randomly assigned (1:1) to receive the SOAR program immediately (experimental group) or after a 9-week delay (control group). SOAR includes 1) one-time Knee Camp (virtual PT-guided group education, knee assessment, 1:1 exercise and physical activity (PA) goal-setting); 2) Weekly personalized home-based exercise and PA program with tracking; 3) Weekly 1:1 PT counseling (virtual). The primary outcome was a change in isokinetic knee extensor strength (baseline to 9-weeks). Additional outcomes included change in self-reported knee-related quality-of-life (QOL), self-efficacy, self-management and kinesiophobia, and PA (accelerometer) at 9 and 18-weeks. Linear regression models estimated the effect of the 8-week intervention at the primary endpoint (9-week).

RESULTS

49 of 54 randomized participants completed the study (91%). Participants were a mean ± standard deviation age of 27 ± 5.0 years, and 2.4 ± 0.9 years post-injury. No mean between group differences for the primary (0.05; 95% confidence interval (CI): -0.10, 0.19) or other outcomes were seen at 9 weeks except for greater improvements in perceived self-management (Partner in Health Scale; 11.3/96, 95%CI: 5.5, 17.1) and kinesiophobia (Tampa Scale of Kinesiophobia; -4.4/33, 95%CI: -7.0, -1.8).

CONCLUSION

For active persons with elevated risk of PTOA, an 8-week SOAR program did not change knee-related strength, QOL, self-efficacy, or PA, on average, but may benefit the ability to self-manage knee health and kinesiophobia.

Changes in Lower Limb Biomechanics Across Various Stages of Maturation and Implications for ACL Injury Risk in Female Athletes: a Systematic Review

BACKGROUND

Female athletes are four to six times more likely to sustain an anterior cruciate ligament (ACL) injury than male athletes. Jump-landing biomechanics are influenced by maturation, with post-pubertal female athletes at a heightened risk of ACL injuries.

OBJECTIVE

The aim of our systematic review was to identify and summarise the current evidence regarding the changes in kinematic and kinetic risk factors associated with ACL injuries during jump-landing tasks in female athletes at various stages of maturity.

METHODS

A systematic search was conducted in PubMed, CINAHL, Web of Science, SPORTDiscus, EMBASE and Scopus. Articles were included if they: (1) conducted the research on uninjured female athletes with no restriction on playing level/experience; (2) provided information regarding the stage of the maturity and the scale used for estimating the maturity status of the participants; and (3) reported a biomechanical risk factor associated with ACL injuries during jump-landing tasks across at least two different maturity groups (e.g. pre-pubertal vs post-pubertal).

RESULTS

Sixteen articles involving 2323 female athletes were included in our review. A total of 12 kinematic and 8 kinetic variables were identified across these studies. Of the 12 kinematic variables reported in our review, we found strong evidence for higher peak knee abduction angle in post-pubertal female individuals compared with pre-pubertal girls (p < 0.05). With regard to the 8 kinetic variables, we found strong evidence for lower relative peak vertical ground reaction force, higher external knee abduction moment and internal rotation moment in post-pubertal compared with pre-pubertal athletes. The strength of evidence for the remaining kinematic and kinetic variables ranged from conflicting to moderate and, in some instances, could not be determined.

CONCLUSIONS

Our study provides an overview of the changes in biomechanical risk factors in female athletes during jump-landing tasks at various stages of maturity. We found moderate-to-limited evidence for most kinematic and kinetic variables, highlighting the need for further research.

Toward designing human intervention studies to prevent osteoarthritis after knee injury: A report from an interdisciplinary OARSI 2023 workshop

Objective

The global impact of osteoarthritis is growing. Currently no disease modifying osteoarthritis drugs/therapies exist, increasing the need for preventative strategies. Knee injuries have a high prevalence, distinct onset, and strong independent association with post-traumatic osteoarthritis (PTOA). Numerous groups are embarking upon research that will culminate in clinical trials to assess the effect of interventions to prevent knee PTOA despite challenges and lack of consensus about trial design in this population. Our objectives were to improve awareness of knee PTOA prevention trial design and discuss state-of-the art methods to address the unique opportunities and challenges of these studies.

Design

An international interdisciplinary group developed a workshop, hosted at the 2023 Osteoarthritis Research Society International Congress. Here we summarize the workshop content and outputs, with the goal of moving the field of PTOA prevention trial design forward.

Results

Workshop highlights included discussions about target population (considering risk, homogeneity, and possibility of modifying osteoarthritis outcome); target treatment (considering delivery, timing, feasibility and effectiveness); comparators (usual care, placebo), and primary symptomatic outcomes considering surrogates and the importance of knee function and symptoms other than pain to this population.

Conclusions

Opportunities to test multimodal PTOA prevention interventions across preclinical models and clinical trials exist. As improving symptomatic outcomes aligns with patient and regulator priorities, co-primary symptomatic (single or aggregate/multidimensional outcome considering function and symptoms beyond pain) and structural/physiological outcomes may be appropriate for these trials. To ensure PTOA prevention trials are relevant and acceptable to all stakeholders, future research should address critical knowledge gaps and challenges.

'It's just my knee': a qualitative study investigating the process of reframing and young athletes' perceived quality of life between anterior cruciate ligament injury and surgery

OBJECTIVES

To understand the factors influencing young athletes' perceptions of quality of life (QOL) following an anterior cruciate ligament (ACL) rupture, prior to reconstructive surgery.

DESIGN

Qualitative descriptive study using semi-structured interviews and thematic analysis of data.

SETTING

Tertiary sports medicine clinic with patients recruited from the practices of three specialist orthopaedic surgeons.

PARTICIPANTS

Twenty athletes aged 14-25 provided consent to participate in the study and completed interviews prior to their ACL reconstruction surgery. Participants were eligible to participate if they were scheduled to undergo ACL reconstruction, were 25 years of age or younger, identified as athletes (participated in any level of organised sport), could communicate in English and agreed to be audio recorded. Participants were not eligible if they had experienced a multiligament injury or fracture.

RESULTS

Young athletes shared common factors that made up their QOL; social connections and support, sport, health, and independence. However, participants' perceptions of their current QOL were quite variable (13-95/100 on a Visual Analogue Scale). Participants who were able to reframe their injury experience by shifting focus to the positive or unaffected aspects of their lives tended to have more favourable perceptions of their QOL than participants who shifted focus to the losses associated with injury.

CONCLUSIONS

Young athletes who have experienced an ACL injury define their QOL based on social support, sport, health and independence. Individual processes of adaptation and cognitive reframing in response to an ACL injury may exert a greater influence on postinjury QOL than the physical ramifications of the injury itself. Understanding individual perceptions may help target potential interventions or supports to enhance athletes' adaptation to injury.

Youth Injury Knowledge and Beliefs following Neuromuscular Training Warm-up Implementation in Schools

Neuromuscular training warm-up programs can reduce injury rates in youth sports, but they often have poor uptake and adherence. Delivering such programs in school physical education classes may provide greater public health benefit, particularly if they promote improved injury knowledge and prevention beliefs amongst students. The purpose of this secondary analysis of a large cluster-randomized controlled trial was to understand how students' (age 11-15 years) knowledge and beliefs change after exposure to an evidence-informed neuromuscular training warm-up program. Six schools delivered the program for a 12-week period in the initial study year (n=566) and two continued to use it in a subsequent "maintenance" year (n=255). Students completed a knowledge and beliefs questionnaire at baseline, 6-week, and 12-week timepoints. Knowledge scores ranged from 7/10 to 8/10 at all timepoints and students generally believed that injuries are preventable. On average, there was less than a one-point change in knowledge between timepoints and there was no change in the median belief scores. There were no meaningful differences between sexes, grades, or previous injury. These findings highlight that knowledge and beliefs are unlikely to change passively through program exposure. More active strategies are needed to improve injury prevention perceptions in this population.

Patellofemoral joint geometry and osteoarthritis features 3-10 years after knee injury compared with uninjured knees

In this cross-sectional study, we compared patellofemoral geometry in individuals with a youth-sport-related intra-articular knee injury to uninjured individuals, and the association between patellofemoral geometry and magnetic resonance imaging (MRI)-defined osteoarthritis (OA) features. In the Youth Prevention of Early OA (PrE-OA) cohort, we assessed 10 patellofemoral geometry measures in individuals 3-10 years following injury compared with uninjured individuals of similar age, sex, and sport, using mixed effects linear regression. We also dichotomized geometry to identify extreme (>1.96 standard deviations) features and assessed likelihood of having extreme values using Poisson regression. Finally, we evaluated the associations between patellofemoral geometry with MRI-defined OA features using restricted cubic spline regression. Mean patellofemoral geometry did not differ substantially between groups. However, compared with uninjured individuals, injured individuals were more likely to have extremely large sulcus angle (prevalence ratio [PR] 3.9 [95% confidence interval, CI: 2.3, 6.6]), and shallow lateral trochlear inclination (PR 4.3 (1.1, 17.9)) and trochlear depth (PR 5.3 (1.6, 17.4)). In both groups, high bisect offset (PR 1.7 [1.3, 2.1]) and sulcus angle (PR 4.0 [2.3, 7.0]) were associated with cartilage lesion, and most geometry measures were associated with at least one structural feature, especially cartilage lesions and osteophytes. We observed no interaction between geometry and injury. Certain patellofemoral geometry features are correlated with higher prevalence of structural lesions compared with injury alone, 3-10 years following knee injury. Hypotheses generated in this study, once further evaluated, could contribute to identifying higher-risk individuals who may benefit from targeted treatment aimed at preventing posttraumatic OA.

The association between knee muscle performance and clinical outcomes of knee function 1-4 years after a sport-related knee joint injury

OBJECTIVE

Estimate the association between index leg knee muscle strength and rate of torque development (RTD), and self-reported and performance-based (i.e., hop) knee function in persons 1-4 years after a sport-related knee joint injury.

METHODS

Data were collected at baseline of a clinical trial. Assessments included the Knee injury and Osteoarthritis Outcome Score Sport & Recreation subscale (KOOSsport), 6-m timed hop (TH), and peak concentric isokinetic knee extensor and flexor torque and isometric RTD. Associations between peak torque and RTD with KOOSsport and TH were assessed using multivariable regression with nonlinear transformations.

RESULTS

53 participants (64.2% female) were included. Knee extensor peak torque was nonlinearly related to TH time, with a strong inverse relationship at lower torque values that changed as torque increased. Results were inconsistent for flexor peak torque, extensor RTD and flexor RTD, with inconsistencies in relationship shape and estimates of association between primary and sensitivity analyses. There was no association between strength/RTD and KOOSsport.

CONCLUSION

There was a nonlinear relationship between knee extensor strength and hop function, with lower strength being associated with a stronger relationship. As strength values increased, the relationship attenuated. Knee extensor and flexor strength, or RTD, were not associated with self-reported function.

Formononetin improves the inflammatory response and bone destruction in knee joint lesions by regulating the NF-kB and MAPK signaling pathways

Formononetin (FMN) is a phytoestrogen that belongs to the isoflavone family. It has antioxidant and anti-inflammatory effects, as well as, many other biological activities. Existing evidence has aroused interest in its ability to protect against osteoarthritis (OA) and promote bone remodeling. To date, research on this topic has not been thorough and many issues remain controversial. Therefore, the purpose of our study was to explore the protective effect of FMN against knee injury and clarify the possible molecular mechanisms. We found that FMN inhibited osteoclast formation induced by receptor activator of NF-κB ligand (RANKL). Inhibition of the phosphorylation and nuclear translocation of p65 in the NF-κB signaling pathway plays a role in this effect. Similarly, during the inflammatory response of primary knee cartilage cells activated by IL-1β, FMN inhibited the NF-κB signaling pathway and the phosphorylation of the ERK and JNK proteins in the MAPK signaling pathway to suppress the inflammatory response. In addition, in vivo experiments showed that both low- and high-dose FMN had a clear protective effect against knee injury in the DMM (destabilization of the medial meniscus) model, and the therapeutic effect of high-dose FMN was stronger. In conclusion, these studies provide evidence of the protective effect of FMN against knee injury.

Knee- and Overall Health-Related Quality of Life Following Anterior Cruciate Ligament Injury: A Cross-sectional Analysis of Australian and Canadian Cohorts

OBJECTIVE: To describe the knee- and overall health-related quality of life (QOL) 3 to 12 years after anterior cruciate ligament (ACL) tear, and to assess the association of clinical and structural features with QOL after ACL tear. DESIGN: Cross-sectional analysis of combined data from Australian (n = 76, 5.4 years postinjury) and Canadian (n = 50, 6.6 years postinjury) prospective cohort studies. METHODS: We conducted a secondary analysis of patient-reported outcomes and index knee magnetic resonance imaging (MRI) acquired in 126 patients (median 5.5 [range: 4-12] years postinjury), all treated with ACL reconstruction. Outcomes included knee (ACL Quality of Life questionnaire [ACL-QOL]) and overall health-related QOL (EQ-5D-3L). Explanatory variables were self-reported knee pain (Knee Injury and Osteoarthritis Outcome Score [KOOS-Pain subscale]) and function (KOOS-Sport subscale), and any knee cartilage lesion (MRI Osteoarthritis Knee Score). Generalized linear models were adjusted for clustering between sites. Covariates were age, sex, time since injury, injury type, subsequent knee injuries, and body mass index. RESULTS: The median [range] ACL-QOL score was 82 [24-100] and EQ-5D-3L was 1.0 [-0.2 to 1.0]. For every 10-point higher KOOS-Sport score, the ACL-QOL score increased by 3.7 points (95% confidence interval [CI]: 1.7, 5.7), whereas there was no evidence of an association with the EQ-5D-3L (0.00 points, 95% CI: -0.02, 0.02). There were no significant association between KOOS-Pain and ACL-QOL (4.9 points, 95% CI: -0.1, 9.9) or EQ-5D-3L (0.05 points, 95% CI: -0.01, 0.11), respectively. Cartilage lesions were not associated with ACL-QOL (-1.2, 95% CI: -5.1, 2.7) or EQ-5D-3L (0.01, 95% CI: -0.01, 0.04). CONCLUSION: Self-reported function was more relevant for knee-related QOL than knee pain or cartilage lesions after ACL tear. Self-reported function, pain, and knee structural changes were not associated with overall health-related QOL. J Orthop Sports Phys Ther 2023;53(7):1-12. Epub: 8 June 2023. doi:10.2519/jospt.2023.11838.

Economic consequences of injury in female Australian footballers: A prospective observational study of emergency department presentations

OBJECTIVE

Investigate the economic consequences of injuries to female Australian footballers from a health sector and societal perspective.

METHODS

This prospective observational study invited 242 females to complete an online questionnaire 3-6 months following an Australian football injury which involved presentation to an ED in Victoria, Australia. The questionnaire inquired regarding healthcare use, time off work, return to playing football and extent of recovery following injury. Relevant information was also extracted from respondents' medical records regarding injury-type, body part injured, investigations and treatments. Healthcare costs were determined for each respondent's ED presentation, hospital admission/s (when relevant), and subsequent healthcare use. Societal costs were determined as lost income to the respondent and/or carer.

RESULTS

A total of 108 people responded to the questionnaire. Sprains/strains and fractures accounted for 84.2% of respondents' injuries. Sixteen respondents (14.8%) required admission to hospital at the time of injury and 81 (75.0%) required subsequent healthcare appointments following discharge from the ED or hospital. Time off work or school following the injury was common (64.8% of respondents) and 27.8% of respondents had a carer take time off work. More than 80% of respondents missed training and matches following the injury. The median healthcare cost per respondent was AUD$753 and the median cost due to work absence was AUD$1393. One-quarter of respondents reported a full recovery.

CONCLUSIONS

Injuries to female Australian footballers can produce substantial healthcare and societal costs, which has important implications for healthcare provision and prioritising and implementing injury prevention programmes and post-injury rehabilitation.

"I feel I'm leading the charge." Experiences of a virtual physiotherapist-guided knee health program for persons at-risk of osteoarthritis after a sport-related knee injury

Objective

Describe participants' perspectives about the feasibility of a virtual, physiotherapist-guided knee health program for people at risk of post-traumatic osteoarthritis after a sport-related knee injury.

Design

Qualitative description study nested within a quasi-experimental study evaluating the feasibility of the Stop OsteoARthritis (SOAR) with persons with sport-related knee injuries. SOAR includes: 1) one-time Knee Camp (group education, 1:1 exercise/activity goal-setting); 2) weekly home-based exercise/activity program with tracking, and; 3) weekly 1:1 physiotherapy-guided action-planning. Upon program completion, semi-structured 1:1 interviews were conducted with participants identified by convenience and maximum variation sampling (age, gender, program satisfaction). Open-ended questions elicited participants' experiences with the program. Content analysis was conducted.

Results

12 women and 4 men [median (min-max) age; 30 (19-46) years] were interviewed. Four categories depicted participants' experiences: 1) 'SOAR satisfies an unmet need' portrayed the perceived relevance and need for a program that promotes knowledge about knee health and self-efficacy for independent exercise behaviour, 2) 'Regaining control of knee health' described how SOAR empowered participants and fostered a sense of 'leading the charge' to their own knee health, 3) 'Social support encourages exercise participation' highlighted that weekly physiotherapy interactions provided accountability for achieving exercise goals, and that relating to other participants was inspirational, 4) 'Program refinements and barriers' suggested enhancements to meet the needs of future participants.

Conclusions

Participants report the SOAR program to be acceptable, relevant, and empowering. Improved knowledge about one's knee health, self-efficacy, autonomy, and social support may encourage exercise adherence and self-management of future knee OA risk.

Is Cumulative Load Associated with Injuries in Youth Team Sport? A Systematic Review

Background

High cumulative external and internal load may predispose athletes to increased risk for injury across a variety of sports, competition levels, and age groups. However, evidence of an association between cumulative load and injury in youth sport remains inconclusive. The objective of this study was to determine the current evidence for cumulative load and injury risk relationships in youth team sport through a systematic review of the existing literature.

Methods

A systematic review of the literature was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Literature searches were conducted in PubMed, Web of Science, SCOPUS, and CINAHL for relevant articles published between January 2010 and April 2021. The authors conducted independent review and quality assessment of the eligible studies. Eleven articles evaluating youth (less than 18 years old) team sport were included for qualitative synthesis.

Results

Fifty-nine percent (n = 39/66) of the relationships assessed revealed an association between cumulative load and injury across the team sports studied, including the presence of load–injury associations in 84% (n = 16/19) of assessments in youth soccer. Of those relationships where an association was present, 79% (n = 31/39) were positive associations between cumulative load and injury. Risk of bias assessment scores ranged from three to six out of seven possible (median = 5) for cohort studies and from four to seven out of 10 possible (median = 5.5) for cross-sectional studies.

Conclusions

There is some evidence for a positive association between load and injury in youth team sport. Youth soccer was the most studied team sport, and a substantial number of positive load–injury associations were reported. Current evidence lacks consistency in the measures and metrics used in defining load–injury relationships.

Trial Registration PRISMA ID - CRD42020203622.

New or Recurrent Knee Injury, Physical Activity, and Osteoarthritis Beliefs in a Cohort of Female Athletes 2 to 3 Years After ACL Reconstruction and Matched Healthy Peers

BACKGROUND

At 2 to 3 years after anterior cruciate ligament reconstruction (ACLR), the relationship between known modifiable osteoarthritis (OA) risk factors and recurrent knee injury is unknown. This study aimed to determine the odds of new or recurrent traumatic knee injury in a cohort of young female athletes with ACLR 2 to 3 years postsurgery compared with healthy control participants. Secondary objectives were to explore the relationships of moderate and vigorous physical activity (MVPA) and body mass index (BMI) with knee injury, and to document self-reported MVPA satisfaction and beliefs about OA.

STUDY DESIGN

Prospective cohort.

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 51 female athletes with unilateral ACLR 1 to 2 years previously and 51 age and sport-matched control participants underwent assessment of MVPA (GT3X accelerometers) and BMI. One year later, participants self-reported knee injuries. Bivariable conditional logistic regression explored the association between knee injury, MVPA, and BMI in each group (injury/control).

RESULTS

At 1-year follow-up (n = 101), 19.6% of the injured cohort and 6.0% of control participants sustained a new or recurrent knee injury. The odds of knee injury for the injury group increased 7-fold over controls [odds ratio (OR) = 7.00 (95% CI = 0.86, 56.90)], although this was not statistically significant. The OR for MVPA was 0.98 (95% CI = 0.93, 1.03) and BMI was OR = 1.24 (95% CI = 0.85, 1.82). Half (56.0%) of injury participants and 66% of controls were satisfied with their MVPA; 81.6% of injury participants believed they had increased knee OA risk compared with someone who had never had a knee injury.

CONCLUSION

In the 2 to 3 years after ACLR, 1 in 5 young female athletes had a new or recurrent knee injury. Based on the point estimate, injured participants were more likely to suffer a traumatic knee injury than matched control participants. MVPA and BMI were not associated with increased odds of knee injury.

CLINICAL RELEVANCE

Clinicians should be encouraged to have in-depth conversations with female athletes with previous ACLR regarding enjoyable and sustainable MVPA participation to promote long-term joint health.

Meniscal repair at the time of primary ACLR does not negatively influence short term knee stability, graft rupture rates, or patient-reported outcome measures: the STABILITY experience

PURPOSE

To assess how meniscal repair and excision impact short term patient-reported outcome measures (PROMs), knee stability, and early graft rupture rates following primary hamstring anterior cruciate ligament reconstruction (ACLR) with or without lateral extra-articular tenodesis (LET) in a group of young active patients where meniscal repair is commonly advocated.

METHODS

Six hundred and eighteen patients under 25 years of age at high-risk of graft failure following ACLR were recruited to the Stability 1 study. Multivariable regression models were developed to identify statistically and clinically significant surgical and demographic predictors of Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee Subjective Knee Form (IKDC), ACL Quality of Life Questionnaire (ACL-QOL) and Marx Activity Rating Scale (MARS) scores. Chi-Square tests of independence were used to explore the association between meniscal status (torn, not torn), meniscal treatment (excision or repair), graft rupture, and rotatory knee laxity.

RESULTS

Medial meniscus repair was associated with worse outcomes on the KOOS (β = -1.32, 95% CI: -1.57 to -1.10, p = 0.003), IKDC (β = -1.66, 95% CI: -1.53 to -1.02, p = 0.031) and ACL-QOL (β = -1.25, 95% CI: -1.61 to 1.02, p = n.s.). However, these associations indicated small, clinically insignificant changes based on reported measures of clinical relevance. Other important predictors of post-operative PROMs included age, sex, and baseline scores. Medial meniscus excision and lateral meniscus treatment (repair or excision) did not have an important influence on PROMs. There was no significant association between meniscal treatment and graft rupture or rotatory knee laxity.

CONCLUSION

While repairing the medial meniscus may result in a small reduction in PROM scores at two-year follow-up, these differences are not likely to be important to patients or clinicians. Any surgical morbidity associated with meniscal repair appears negligible in terms of PROMs. Meniscal repair does not affect rotatory laxity or graft failure rates in the short term. Therefore, meniscal repair should likely be maintained as the standard of care for concomitant meniscal tears with ACLR.

LEVEL OF EVIDENCE

III.

Post-traumatic knee osteoarthritis; the role of inflammation and hemarthrosis on disease progression

Knee injuries such as anterior cruciate ligament ruptures and meniscal injury are common and are most frequently sustained by young and active individuals. Knee injuries will lead to post-traumatic osteoarthritis (PTOA) in 25–50% of patients. Mechanical processes where historically believed to cause cartilage breakdown in PTOA patients. But there is increasing evidence suggesting a key role for inflammation in PTOA development. Inflammation in PTOA might be aggravated by hemarthrosis which frequently occurs in injured knees. Whereas mechanical symptoms (joint instability and locking of the knee) can be successfully treated by surgery, there still is an unmet need for anti-inflammatory therapies that prevent PTOA progression. In order to develop anti-inflammatory therapies for PTOA, more knowledge about the exact pathophysiological mechanisms and exact course of post-traumatic inflammation is needed to determine possible targets and timing of future therapies.

Concurrent validity and reliability of a semi-automated approach to measuring the magnetic resonance imaging morphology of the knee joint in active youth

Post-traumatic knee osteoarthritis is attributed to alterations in joint morphology, alignment, and biomechanics triggered by injury. While magnetic resonance (MR) imaging-based measures of joint morphology and alignment are relevant to understanding osteoarthritis risk, time consuming manual data extraction and measurement limit the number of outcomes that can be considered and deter widespread use. This paper describes the development and evaluation of a semi-automated software for measuring tibiofemoral and patellofemoral joint architecture using MR images from youth with and without a previous sport-related knee injury. After prompting users to identify and select key anatomical landmarks, the software can calculate 37 (14 tibiofemoral, 23 patellofemoral) relevant geometric features (morphology and alignment) based on established methods. To assess validity and reliability, 11 common geometric features were calculated from the knee MR images (proton density and proton density fat saturation sequences; 1.5 T) of 76 individuals with a 3–10-year history of youth sport-related knee injury and 76 uninjured controls. Spearman’s or Pearson’s correlation coefficients (95% CI) and Bland-Altman plots were used to assess the concurrent validity of the semi-automated software (novice rater) versus expert manual measurements, while intra-class correlation coefficients (ICC2,1; 95%CI), standard error of measurement (95%CI), 95% minimal detectable change, and Bland-Altman plots were used to assess the inter-rater reliability of the semi-automated software (novice vs resident radiologist rater). Correlation coefficients ranged between 0.89 (0.84, 0.92; Lateral Trochlear Inclination) and 0.97 (0.96, 0.98; Patellar Tilt Angle). ICC estimates ranged between 0.79 (0.63, 0.88; Lateral Patellar Tilt Angle) and 0.98 (0.95, 0.99; Bisect Offset). Bland-Altman plots did not reveal systematic bias. These measurement properties estimates are equal, if not better than previously reported methods suggesting that this novel semi-automated software is an accurate, reliable, and efficient alternative method for measuring large numbers of geometric features of the tibiofemoral and patellofemoral joints from MR studies.

Efficacy of the SOAR knee health program: protocol for a two-arm stepped-wedge randomized delayed-controlled trial

BACKGROUND

Knee trauma permanently elevates one's risk for knee osteoarthritis. Despite this, people at-risk of post-traumatic knee osteoarthritis rarely seek or receive care, and accessible and efficacious interventions to promote knee health after injury are lacking. Exercise can ameliorate some mechanisms and independent risk factors for osteoarthritis and, education and action-planning improve adherence to exercise and promote healthy behaviours.

METHODS

To assess the efficacy of a virtually-delivered, physiotherapist-guided exercise-based program (SOAR) to improve knee health in persons discharged from care after an activity-related knee injury, 70 people (16-35 years of age, 12-48 months post-injury) in Vancouver Canada will be recruited for a two-arm step-wedged assessor-blinded delayed-control randomized trial. Participants will be randomly allocated to receive the intervention immediately or after a 10-week delay. The program consists of 1) one-time Knee Camp (group education, 1:1 individualized exercise and activity goal-setting); 2) weekly individualized home-based exercise and activity program with tracking, and; 3) weekly 1:1 physiotherapy-guided action-planning with optional group exercise class. Outcomes will be measured at baseline, 9- (primary endpoint), and 18-weeks. The primary outcome is 9-week change in knee extension strength (normalized peak concentric torque; isokinetic dynamometer). Secondary outcomes include 9-week change in moderate-to-vigorous physical activity (accelerometer) and self-reported knee-related quality-of-life (Knee injury and OA Outcome Score subscale) and self-efficacy (Knee Self Efficacy Scale). Exploratory outcomes include 18-week change in primary and secondary outcomes, and 9- and 18- week change in other components of knee extensor and flexor muscle function, hop function, and self-reported symptoms, function, physical activity, social support, perceived self-care and kinesiophobia. Secondary study objectives will assess the feasibility of a future hybrid effectiveness-implementation trial protocol, determine the optimal intervention length, and explore stakeholder experiences.

DISCUSSION

This study will assess the efficacy of a novel, virtually-delivered, physiotherapist-guided exercise-based program to optimize knee health in persons at increased risk of osteoarthritis due to a past knee injury. Findings will provide valuable information to inform the management of osteoarthritis risk after knee trauma and the conduct of a future effectiveness-implementation trial.

TRIAL REGISTRATION

Clinicaltrials.gov reference: NTC04956393. Registered August 5, 2021, https://clinicaltrials.gov/ct2/show/NCT04956393?term=SOAR&cond=osteoarthritis&cntry=CA&city=Vancouver&draw=2&rank=1.

Balance, reframe, and overcome: The attitudes, priorities, and perceptions of exercise-based activities in youth 12-24 months after a sport-related ACL injury

Attitudes, priorities, and perceptions of exercise directly influence exercise behaviors. Despite the benefits of exercise-based activities for future health, little is known about how youth who experience an ACL injury view exercise-based activity beyond the immediate recovery period. A qualitative (interpretative description) approach with one-to-one semistructured interviews was used to probe the current attitudes, priorities, and perceptions of exercise-therapy, physical activity, and sport participation with a purposive sample of youth from an ongoing inception cohort study who experienced an ACL tear or reconstruction in the past 12-24 months. Analyses followed an inductive approach guided by an analytic interpretative description process. Reflexive journaling, memoing, and a detailed audit trail promoted data trustworthiness. A patient-partner was involved throughout. Ten youth (six women, four men), 15-19 years of age, and a median of 20-months (16-26) from injury were interviewed. Three overarching themes were identified. 'Balancing physical activity and future knee health' highlighted ongoing negotiations between what were perceived to be competing priorities for return-to-sport and future knee health. 'Reframing the value of exercise-therapy and physical activity' reflected the importance of reshaping attitudes toward exercise as positive and was linked to exercise adherence. 'Overcoming unforeseen exercise challenges' encompassed persisting psychological and physical challenges perceived to limit exercise-based activities. Clinical significance: reframing exercise-based activities in a positive light and leveraging motivation for return-to-sport and life-long knee health may be important strategies for encouraging ongoing exercise therapy and physical activity following a youth ACL injury.

Health-Related Outcomes 3-15 Years Following Ankle Sprain Injury in Youth Sport: What Does the Future Hold?

BACKGROUND

This study examined the association between youth sport-related ankle sprain injury and health-related outcomes, 3-15 years postinjury.

METHODS

A historical cohort study in which uninjured controls were cluster-matched with injured cases. The primary outcome was self-reported Foot and Ankle Outcome Score (FAOS). Secondary outcomes included measures of adiposity, validated questionnaires for physical activity, athletic identity, fear of pain, and tests of strength, balance, and function.

RESULTS

We recruited 86 participants (median age of 23 years; 77% female); 50 with a time-loss ankle sprain, median of 8 years postinjury, and 36 uninjured controls cluster-matched by sex and sport. Based on mixed effects multivariable regression models, previously injured participants demonstrated poorer outcomes than controls on all 5 FAOS subscales regardless of sex and time since injury, with the largest differences observed in symptoms (-20.9, 99% CI: -29.5 to -12.3) and ankle-related quality of life (-25.3, 99% CI: -34.7 to -15.9) subscales. Injured participants also had poorer unipedal dynamic balance (-1.9, 99% CI: 3.5 to -0.2) and greater fear of pain (7.2, 99% CI: 0.9-13.4) compared with controls. No statistically significant differences were found for other secondary outcomes.

CONCLUSION

At 3-15 years following time-loss ankle sprain injury in youth sport, previously injured participants had more pain and symptoms, poorer self-reported function, ankle-related quality of life, reduced sport participation, balance, and greater fear of pain than controls. This underlines the need to promote the primary prevention of ankle sprains and secondary prevention of potential health consequences, including posttraumatic osteoarthritis.

LEVEL OF EVIDENCE

Level III, historical cohort study.

Vertical Drop Jump Biomechanics of Patients With a 3- to 10-Year History of Youth Sport-Related Anterior Cruciate Ligament Reconstruction

Background

A better understanding of movement biomechanics after anterior cruciate ligament reconstruction (ACLR) could inform injury prevention, knee injury rehabilitation, and osteoarthritis prevention strategies.

Purpose

To investigate differences in vertical drop jump (VDJ) biomechanics between patients with a 3- to 10-year history of youth sport-related ACLR and uninjured peers of a similar age, sex, and sport.

Study Design

Cross-sectional study. Level of evidence III.

Methods

Lower limb kinematics and bilateral ground-reaction forces (GRFs) were recorded for participants performing 10 VDJs. Joint angles and GRF data were analyzed, and statistical analysis was performed using 2 multivariate models. Dependent variables included sagittal (ankle, knee, and hip) and coronal (knee and hip) angles at initial contact and maximum knee flexion, the rate of change of coronal knee angles (35%-90% of the support phase; ie, slopes of linear regression lines), and vertical and mediolateral GRFs (normalized to body weight [BW]). Fixed effects included group, sex, and time since injury. Participant clusters, defined by sex and sport, were considered as random effects.

Results

Participants included 48 patients with a history of ACLR and 48 uninjured age-, sex-, and sport-matched controls (median age, 22 years [range, 18-26 years]; 67% female). Patients with ACLR demonstrated steeper negative coronal knee angle slopes (β = -0.04 deg/% [95% CI, -0.07 to -0.00 deg/%]; P = .025). A longer time since injury was associated with reduced knee flexion (β = -0.2° [95% CI, -0.3° to -0.0°]; P = .014) and hip flexion (β = -0.1° [95% CI, -0.2° to -0.0°]; P = .018). Regardless of ACLR history, women displayed greater knee valgus at initial contact (β = 2.1° [95% CI, 0.4° to 3.8°]; P = .017), greater coronal knee angle slopes (β = 0.05 deg/% [95% CI, 0.02 to 0.09 deg/%]; P = .004), and larger vertical GRFs (landing: β = -0.34 BW [95% CI, -0.61 to -0.07 BW]; P = .014) (pushoff: β = -0.20 BW [95% CI, -0.32 to -0.08 BW]; P = .001).

Conclusion

Women and patients with a 3- to 10-year history of ACLR demonstrated VDJ biomechanics that may be associated with knee motion control challenges.

Clinical Relevance

It is important to consider knee motion control during activities such as VDJs when developing injury prevention and rehabilitation interventions aimed at improving joint health after youth sport-related ACLR.

A lifespan approach to osteoarthritis prevention

Prevention is an attractive solution for the staggering and increasingly unmanageable burden of osteoarthritis. Despite this, the field of osteoarthritis prevention is relatively immature. To date, most of what is known about preventing osteoarthritis and risk factors for osteoarthritis is relative to the disease (underlying biology and pathophysiology) of osteoarthritis, with few studies considering risk factors for osteoarthritis illness, the force driving the personal, financial and societal burden. In this narrative review we will discuss what is known about osteoarthritis prevention, propose actionable prevention strategies related to obesity and joint injury which have emerged as important modifiable risk factors, identify where evidence is lacking, and give insight into what might be possible in terms of prevention by focussing on a lifespan approach to the illness of osteoarthritis, as opposed to a structural disease of the elderly. By targeting a non-specialist audience including scientists, clinicians, students, industry employees and others that are interested in osteoarthritis but who do not necessarily focus on osteoarthritis, the goal is to generate discourse and motivate inquiry which propel the field of osteoarthritis prevention into the mainstream.

Change of Direction Biomechanics in a 180-Degree Pivot Turn and the Risk for Noncontact Knee Injuries in Youth Basketball and Floorball Players

BACKGROUND

Studies investigating biomechanical risk factors for knee injuries in sport-specific tasks are needed.

PURPOSE

To investigate the association between change of direction (COD) biomechanics in a 180-degree pivot turn and knee injury risk among youth team sport players.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A total of 258 female and male basketball and floorball players (age range, 12-21 years) participated in the baseline COD test and follow-up. Complete data were obtained from 489 player-legs. Injuries, practice, and game exposure were registered for 12 months. The COD test consisted of a quick ball pass before and after a high-speed 180-degree pivot turn on the force plates. The following variables were analyzed: peak vertical ground-reaction force (N/kg); peak trunk lateral flexion angle (degree); peak knee flexion angle (degree); peak knee valgus angle (degree); peak knee flexion moment (N·m/kg); peak knee abduction moment (N·m/kg); and peak knee internal and external rotation moments (N·m/kg). Legs were analyzed separately and the mean of 3 trials was used in the analysis. Main outcome measure was a new acute noncontact knee injury.

RESULTS

A total of 18 new noncontact knee injuries were registered (0.3 injuries/1000 hours of exposure). Female players sustained 14 knee injuries and male players 4. A higher rate of knee injuries was observed in female players compared with male players (incidence rate ratio, 6.2; 95% CI, 2.1-21.7). Of all knee injuries, 8 were anterior cruciate ligament (ACL) injuries, all in female players. Female players displayed significantly larger peak knee valgus angles compared with male players (mean for female and male players, respectively: 13.9°± 9.4° and 2.0°± 8.5°). No significant associations between biomechanical variables and knee injury risk were found.

CONCLUSION

Female players were at increased risk of knee and ACL injury compared with male players. Female players performed the 180-degree pivot turn with significantly larger knee valgus compared with male players. However, none of the investigated variables was associated with knee injury risk in youth basketball and floorball players.

What Does the Future Hold? Health-Related Quality of Life 3-12 Years Following a Youth Sport-Related Knee Injury

Knee trauma can lead to poor health-related quality of life (HRQoL) and osteoarthritis. We aimed to assess HRQoL 3–12 years following youth sport-related knee injury considering HRQoL and osteoarthritis determinants. Generic (EQ-5D-5L index, EQ-VAS) and condition-specific (Knee injury and Osteoarthritis Outcome Score quality of life subscale, KOOS QOL) HRQoL were assessed in 124 individuals 3–12 years following youth sport-related knee injury and 129 uninjured controls of similar age, sex, and sport. Linear regression examined differences in HRQoL outcomes by injury group. Multivariable linear regression explored the influence of sex, time-since-injury, injury type, body mass index, knee muscle strength, Intermittent and Constant Osteoarthritis Pain (ICOAP) score, and Godin Leisure-Time Exercise Questionnaire (GLTEQ) moderate-to-strenuous physical activity. Participant median (range) age was 23 years (14–29) and 55% were female. Injury history was associated with poorer KOOS QOL (−8.41; 95%CI −10.76, −6.06) but not EQ-5D-5L (−0.0074; −0.0238, 0.0089) or EQ-VAS (−3.82; −8.77, 1.14). Injury history (−5.14; −6.90, −3.38), worse ICOAP score (−0.40; −0.45, −0.36), and anterior cruciate ligament tear (−1.41; −2.77, −0.06) contributed to poorer KOOS QOL. Worse ICOAP score contributed to poorer EQ-5D-5L (−0.0024; −0.0034, −0.0015) and higher GLTEQ moderate-to-strenuous physical activity to better EQ-VAS (0.10; 0.03, 0.17). Knee trauma is associated with poorer condition-specific but not generic HRQoL 3–12 years post-injury.

Narrative Review - Knee Pain in the Pediatric Athlete

PURPOSE OF REVIEW

This review article seeks to highlight common youth athlete knee conditions due to overuse or trauma and elucidate differences from the adult populations.

RECENT FINDINGS

Overuse conditions presented include apophysitis, osteochondritis dissecans plica syndrome, and discoid meniscus. Traumatic conditions presented include patellar instability, patellar sleeve fracture, and patellofemoral osteochondral fractures. Knee injuries affect a significant proportion of youth athletes. These injuries place athletes at higher risk of chronic pain and potentially osteoarthritis. We have reviewed common overuse and traumatic knee injuries and differentiating factors between the adult population to improve and expedite the diagnosis, treatment, and prognosis for youth athletes with knee injuries.

Does sex affect second ACL injury risk? A systematic review with meta-analysis

OBJECTIVE

To determine sex-based differences in risk of a second ACL injury (overall and by laterality) following primary ACL reconstruction in athletes who are attempting to return to sport.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Systematic search of five databases conducted in August 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies reporting sex-based differences in the incidence of second ACL injury in athletes attempting to return-to-sports and who were followed for at least 1 year following primary ACL reconstruction.

RESULTS

Nineteen studies were included in this review, with seven studies excluded from the primary meta-analysis due to high risk of bias. The remaining 12 studies (n=1431 females, n=1513 males) underwent meta-analysis, with all 19 studies included in a sensitivity analysis. Total second ACL injury risk was 21.9% (females: 22.8%, males: 20.3%). Females were found to have 10.7% risk of an ipsilateral ACL injury and 11.8% risk of a contralateral ACL injury. Males were found to have 12.0% risk of an ipsilateral ACL injury and 8.7% risk of a contralateral ACL injury. No statistically significant differences were observed for total second ACL injury risk (risk difference=-0.6%, 95% CI -4.9 to 3.7, p=0.783, I²=41%) or contralateral ACL injury risk (risk difference=1.9%, 95% CI -0.5% to 4.4%, p=0.113, I²=15%) between sexes. Females were found to have a 3.4% absolute risk reduction in subsequent ipsilateral ACL injury risk compared with males (risk difference=-3.4%, 95% CI -6.7% to -0.02%, p=0.037, I²=35%).

CONCLUSION

Both sexes have >20% increased risk of experiencing a second ACL injury. Any difference in the absolute risk of either a subsequent ipsilateral or contralateral ACL injury between sexes appears to be small.

REGISTRATION

PROSPERO (CRD42020148369).

Effect of Anterior Cruciate Ligament Rupture on Physical Activity, Sports Participation, Patient-Reported Health Outcomes, and Physical Function in Young Female Athletes

BACKGROUND

Return to sports (RTS) is frequently considered an indicator of successful recovery after anterior cruciate ligament reconstruction (ACLR). However, despite the well-recognized health benefits of physical activity (PA), little is known about objectively measured PA in the 1 to 2 years after ACLR. Given that young female athletes have a high prevalence of ACLR and lower RTS rates as compared with their male counterparts, an in-depth examination of PA in this subgroup is warranted.

HYPOTHESIS

We hypothesized that female youth and young adults who have had ACLR in the previous 1 to 2 years would have less moderate or vigorous PA (MVPA) compared with healthy matched controls. We also hypothesized that the ACLR group would report lower levels of sports participation, patient-reported health outcomes, and physical function.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Participants included 51 female athletes with primary unilateral ACLR for a sports-related injury in the previous 1 to 2 years and 51 age- and sports-matched controls. Outcomes included objectively measured PA (GT3X accelerometers), previous and current sports participation and RTS, body mass index, Knee injury and Osteoarthritis Outcome Score (KOOS), triple single-leg hop, and one-leg rise. Mean within-pair differences with 95% CIs were used to assess differences between groups across all outcomes. Multivariable linear regression (clustered by pair) was used to examine whether the ACLR group had less MVPA than did the age- and sports-matched control group, adjusting for total wear time, age, time since injury, and body mass index.

RESULTS

Median age was 17.8 years (range, 14.6-22.6 years). There was no significant difference between groups in MVPA. However, the injury group had fewer mean minutes per day of vigorous PA (-1.22; 95% CI, -2.40 to -0.04), poorer KOOS values on all subscales, and shorter triple single-leg hop distance. In the injury group, 28 (55%) returned to sports, including 14 (27.5%) who returned at preinjury performance level. Across both groups, over one-third changed their most important sport, shifting toward an individual-based sport.

CONCLUSION

At 1 to 2 years after ACLR, female athletes demonstrated no differences in combined MVPA and only a very small reduction in vigorous PA, yet they had higher levels of self-reported knee pain and symptoms, reduced knee function in sports, lower quality of life, and poorer objective knee function compared with matched controls.

Sports injuries and illnesses at the Lausanne 2020 Youth Olympic Winter Games: a prospective study of 1783 athletes from 79 countries

OBJECTIVE

To describe the injury and illness characteristics among participating athletes during the Lausanne 2020 Youth Olympic Winter Games (YOG 2020), 9-22 January 2020.

METHODS

The daily number of athlete injuries and illnesses were recorded (1) through the reporting of all National Olympic Committee (NOC) medical teams and (2) in the polyclinic and medical venues by the Lausanne 2020 medical staff.

RESULTS

In total, 1783 athletes from 79 NOCs were observed. NOC and Lausanne 2020 medical staff reported 228 injuries and 167 illnesses, equating 11.7 injuries and 8.6 illnesses per 100 athletes over the 14-day period. Injury incidence was highest for snowboard slopestyle (39%), bobsleigh (36%), snowboard big air (29%), ski slopestyle (29%), snowboard cross (24%) and ski cross (21%), and lowest for speed skating, snowboard halfpipe and curling (2%-4%). The highest incidence of illness was recorded for curling (21%), ski mountaineering (15%), snowboard halfpipe (13%), bobsleigh (11%), cross-country skiing (10%) and figure skating (10%). Almost one-third of injuries were expected to result in time loss and 17% of illnesses. Most injuries occurred to the knee (12%) and head (11%), and 64% of illnesses affected the respiratory system. Overall, women suffered more injuries and illness than males.

CONCLUSION

Overall, injury and illness rates were similar compared with recent YOG. While the rate and characteristics of injury and illness varied between sports, consistent patterns across YOG are emerging. If addressed, changes in highlighted areas of risk could have a positive impact on the health and well-being of these young athletes.

Knee Injury and Osteoarthritis Outcome Score (KOOS) Responder Criteria and Minimal Detectable Change 3-12 Years Following a Youth Sport-Related Knee Injury

The applicability of thresholds that constitute an acceptable score or meaningful change on the Knee injury and Osteoarthritis Outcome Score (KOOS) in cohorts ≥ 5 years following knee injury is not well understood. The primary objective of this study was to evaluate the association between intra-articular knee injury type and two different KOOS pain thresholds (patient acceptable symptom state (PASS) and Englund symptomatic knee criteria) in the Alberta Youth Prevention of Osteoarthritis (PrE-OA) cohort, which includes participants 3–12 years following a youth sport-related knee injury and uninjured controls with similar age, sex and sport characteristics. Analyses accounted for sex, time since injury and the interaction between time since injury and injury type. Secondary objectives were to report proportions meeting thresholds for KOOS outcomes and minimal detectable change (MDC) from published test–retest reliability data, over a 1–4-year follow-up. Two hundred and fifty-three (253) participants (124 injured, 129 controls) were included in analyses, of which 153 (77 injured, 76 controls) had follow-up data. Similar odds were observed for presence of pain (below PASS threshold) in participants with anterior cruciate ligament (ACL)/meniscus injury (odds ratio (OR) 4.2 (97.5% confidence interval (CI): 1.8, 9.9)) and other knee injuries (OR 4.9 (97.5% CI: 1.2, 21.0)), while there were higher odds for presence of Englund “symptomatic knee” criteria in participants with ACL/meniscus injury (OR 13.6 (97.5% CI: 2.9, 63.4)) than other knee injuries (OR 7.3 (97.5% CI: 0.8, 63.7)) compared to controls. After a median 23.4 (8 to 42) month follow-up, 35% of previously injured participants had at least one KOOS sub-scale score that worsened by more than the MDC published threshold. Despite limited research, this study shows that individuals with youth sport knee injuries other than ACL or meniscus injury may also experience significant pain and symptoms 3–12 years following injury. Replication and further follow-up are needed to identify a possible clinical trajectory towards osteoarthritis.

Linear Discriminant Analysis Successfully Predicts Knee Injury Outcome From Biomechanical Variables

BACKGROUND

The most commonly damaged structures of the knee are the anterior cruciate ligament (ACL), medial collateral ligament (MCL), and menisci. Given that these injuries present as either isolated or concomitant, it follows that these events are driven by specific mechanics versus coincidence. This study was designed to investigate the multiplanar mechanisms and determine the important biomechanical and demographic factors that contribute to classification of the injury outcome.

HYPOTHESIS

Linear discriminant analysis (LDA) would accurately classify each injury type generated by the mechanical impact simulator based on biomechanical input variables (ie, ligament strain and knee kinetics).

STUDY DESIGN

Controlled laboratory study.

METHODS

In vivo kinetics and kinematics of 42 healthy, athletic participants were measured to determine stratification of injury risk (ie, low, medium, and high) in 3 degrees of knee forces/moments (knee abduction moment, anterior tibial shear, and internal tibial rotation). These stratified kinetic values were input into a cadaveric impact simulator to assess ligamentous strain and knee kinetics during a simulated landing task. Uniaxial and multiaxial load cells and implanted strain sensors were used to collect mechanical data for analysis. LDA was used to determine the ability to classify injury outcome by demographic and biomechanical input variables.

RESULTS

From LDA, a 5-factor model (Entropy R2 = 0.26) demonstrated an area under the receiver operating characteristic curve (AUC) for all 5 injury outcomes (ACL, MCL, ACL+MCL, ACL+MCL+meniscus, ACL+meniscus) of 0.74 or higher, with "good" prediction for 4 of 5 injury classifications. A 10-factor model (Entropy R2 = 0.66) improved the AUC to 0.86 or higher, with "excellent" prediction for 5 injury classifications. The 15-factor model (Entropy R2 = 0.85), produced 94.1% accuracy with the AUC 0.98 or higher for all 5 injury classifications.

CONCLUSION

Use of LDA accurately predicted the outcome of knee injury from kinetic data from cadaveric simulations with the use of a mechanical impact simulator at 25° of knee flexion. Thus, with clinically relevant kinetics, it is possible to determine clinical risk of injury and also the likely presentation of singular or concomitant knee injury.

CLINICAL RELEVANCE

LDA demonstrates that injury outcomes are largely characterized by specific mechanics that can distinguish ACL, MCL, and medial meniscal injury. Furthermore, as the mechanics of injury are better understood, improved interventional prehabilitation can be designed to reduce these injuries.

Towards improving the identification of anterior cruciate ligament tears in primary point-of-care settings

Background

Only a small proportion of anterior cruciate ligament (ACL) tears are diagnosed on initial healthcare consultation. Current clinical guidelines do not acknowledge that primary point-of-care practitioners rely more heavily on a clinical history than special clinical tests for diagnosis of an ACL tear. This research will assess the accuracy of combinations of patient-reported variables alone, and in combination with clinician-generated variables to identify an ACL tear as a preliminary step to designing a primary point-of-care clinical decision support tool.

Methods

Electronic medical records (EMRs) of individuals aged 15–45 years, with ICD-9 codes corresponding to a knee condition, and confirmed (ACL⁺) or denied (ACL⁻) first-time ACL tear seen at a University-based Clinic between 2014 and 2016 were eligible for inclusion. Demographics, relevant diagnostic indicators and ACL status based on orthopaedic surgeon assessment and/or MRI reports were manually extracted. Descriptive statistics calculated for all variables by ACL status. Univariate between group comparisons, clinician surveys (n = 17), availability of data and univariable logistic regression (95%CI) were used to select variables for inclusion into multivariable logistic regression models that assessed the odds (95%CI) of an ACL-tear based on patient-reported variables alone (consistent with primary point-of-care practice), or in combination with clinician-generated variables. Model performance was assessed by accuracy, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios (95%CI).

Results

Of 1512 potentially relevant EMRs, 725 were included. Participant median age was 26 years (range 15–45), 48% were female and 60% had an ACL tear. A combination of patient-reported (age, sport-related injury, immediate swelling, family history of ACL tear) and clinician-generated (Lachman test result) variables were superior for ACL tear diagnosis [accuracy; 0.95 (90,98), sensitivity; 0.97 (0.88,0.98), specificity; 0.95 (0.82,0.99)] compared to the patient-reported variables alone [accuracy; 84% (77,89), sensitivity; 0.60 (0.44,0.74), specificity; 0.95 (0.89,0.98)].

Conclusions

A high proportion of individuals without an ACL tear can be accurately identified by considering patient-reported age, injury setting, immediate swelling and family history of ACL tear. These findings directly inform the development of a clinical decision support tool to facilitate timely and accurate ACL tear diagnosis in primary care settings.

Implementing a junior high school-based programme to reduce sports injuries through neuromuscular training (iSPRINT): a cluster randomised controlled trial (RCT)

Objective

To evaluate the effectiveness of a junior high school-based sports injury prevention programme to reduce injuries through neuromuscular training (NMT).

Methods

This was a cluster randomised controlled trial. Students were recruited from 12 Calgary junior high schools (2014–2017). iSPRINT is a 15 min NMT warm-up including aerobic, agility, strength and balance exercises. Following a workshop, teachers delivered a 12-week iSPRINT NMT (six schools) or a standard-of-practice warm-up (six schools) in physical education classes. The definition of all recorded injuries included injuries that resulted in participants being unable to complete a sport and recreation (S&R) session, lost time from sport and/or seek medical attention. Incidence rate ratios (IRRs) were estimated based on multiple multilevel Poisson regression analyses (adjusting for sex (considering effect modification) and previous injury, offset by S&R participation hours, and school-level and class-level random effects were examined) for intent-to-treat analyses.

Results

1067 students (aged 11–16) were recruited across 12 schools (6 intervention schools (22 classes), 6 control schools (27 classes); 53.7% female, 46.3% male). The iSPRINT programme was protective of all recorded S&R injuries for girls (IRR=0.543, 95% CI 0.295 to 0.998), but not for boys (IRR=0.866, 95% CI 0.425 to 1.766). The iSPRINT programme was also protective of each of lower extremity injuries (IRR=0.357, 95% CI 0.159 to 0.799) and medical attention injuries (IRR=0.289, 95% CI 0.135 to 0.619) for girls, but not for boys (IRR=1.055, 95% CI 0.404 to 2.753 and IRR=0.639, 95% CI 0.266 to 1.532, respectively).

Conclusion

The iSPRINT NMT warm-up was effective in preventing each of all recorded injuries, lower extremity injuries and medically treated S&R injuries in female junior high school students.

Trial registration number

NCT03312504

Establishing outcome measures in early knee osteoarthritis

The classification and monitoring of individuals with early knee osteoarthritis (OA) are important considerations for the design and evaluation of therapeutic interventions and require the identification of appropriate outcome measures. Potential outcome domains to assess for early OA include patient-reported outcomes (such as pain, function and quality of life), features of clinical examination (such as joint line tenderness and crepitus), objective measures of physical function, levels of physical activity, features of imaging modalities (such as of magnetic resonance imaging) and biochemical markers in body fluid. Patient characteristics such as adiposity and biomechanics of the knee could also have relevance to the assessment of early OA. Importantly, research is needed to enable the selection of outcome measures that are feasible, reliable and validated in individuals at risk of knee OA or with early knee OA. In this Perspectives article, potential outcome measures for early symptomatic knee OA are discussed, including those measures that could be of use in clinical practice and/or the research setting.

A pragmatic approach to prevent post-traumatic osteoarthritis after sport or exercise-related joint injury

Lower extremity musculoskeletal injuries are common in sport and exercise, and associated with increased risk of obesity and post-traumatic osteoarthritis (PTOA). Unlike other forms of osteoarthritis, PTOA is common at a younger age and associated with more rapid progression, which may impact career choices, long-term general health and reduce quality of life. Individuals who suffer an activity-related joint injury and present with abnormal joint morphology, elevated adiposity, weak musculature, or become physically inactive are at increased risk of PTOA. Insufficient exercise therapy or incomplete rehabilitation, premature return-to-sport and re-injury, unrealistic expectations, or poor nutrition may further elevate this risk. Delay in surgical interventions in lieu of exercise therapy to optimize muscle strength and neuromuscular control while addressing fear of movement to guarantee resumption of physical activity, completeness of rehabilitation before return-to-sport, education that promotes realistic expectations and self-management, and nutritional counseling are the best approaches for delaying or preventing PTOA.

Motivation for sports participation, injury prevention expectations, injury risk perceptions and health problems in youth floorball players

PURPOSE

Describe the motivation for floorball participation, injury prevention expectations, injury risk perceptions and prevalence of health problems in youth floorball players at the start of the season.

METHODS

This cross-sectional survey is part of a larger Sport Without Injury ProgrammE (SWIPE) project and provides baseline data before a cluster randomised controlled trial of an injury prevention program (Knee Control). A baseline survey (online and paper based) was collected from 47 teams with 471 youth floorball players from two provinces of Sweden before the start of the 2017 season.

RESULTS

The mean age for 140 females and 331 males was 13.7 (± 1.5) and 13.3 (± 1.0) years, respectively. The two most significant motivators for floorball participation were being part of the team (82% females, 75% males) and friends (65% females, 70% males). Fractures (84% females, 90% males), eye injuries (90% females, 83% males) and concussion (82% females, 83% males) were perceived as the most severe injuries. 93% of players believed that sports injuries can be prevented, while 74% believed it is unlikely that they will sustain an injury. Existing health problems at the beginning of the season were prevalent in 33% of players, with 65% being injuries and 35% illnesses. 17% of existing injuries at the start of the season caused time-loss from play and 17% required medical attention.

CONCLUSION

Social aspects were the greatest motivators for floorball participation in youths, suggesting that these factors are important to retain sports participants. The high number of health problems in youth is a concern; as such more effort, resources and priority should be given to sports safety programs. Many players believed that sports injuries can be prevented, possibly providing a fertile ground for implementation of such programs.

LEVEL OF EVIDENCE

IV.