Biomechanical and Functional Outcomes After Medial Patellofemoral Ligament Reconstruction: A Pilot Study.

BACKGROUND: Previous studies have acknowledged the medial patellofemoral ligament (MPFL) as the primary stabilizer of the patella, preventing lateral displacement. MPFL reconstruction (MPFL-R) restores stability and functionality to the patellofemoral joint and has emerged as a preferred treatment option for recurrent lateral patellar instability. PURPOSE: To objectively measure biomechanical characteristics of athletes cleared for return to sport after MPFL-R compared with healthy controls. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A prospective case-control study design was employed on 31 total athletes. Sixteen athletes (6 male, 10 female; mean age, 16.1 ± 2.74 years; 385 ± 189 days after surgery and 235 ± 157 days after return to sport) underwent MPFL-R and were medically cleared to return to sport. This group was matched by age, sex, and activity level to 15 healthy athletes with no history of lower extremity injuries. Athletes and controls completed validated questionnaires as well as hopping, jumping, and cutting tests with 3-dimensional motion analysis and underwent strength, flexibility, laxity, and balance assessments. RESULTS: Participants in the MPFL-R group scored significantly lower (worse) on the International Knee Documentation Committee (IKDC) (89.2 ± 7.6 vs 98.1 ± 2.0, respectively; P = .0005) and significantly higher (worse) on the Tampa Scale for Kinesiophobia (TSK) (32.4 ± 5.0 vs 25.4 ± 6.5, respectively; P = .006) than those in the control group, but there was no difference in the Kujala score (95.6 ± 5.3 vs 98.8 ± 3.0, respectively; P = .06). Participants in the MPFL-R group demonstrated reduced hip and ankle flexion relative to those in the control group (P < .05). Participants in the MPFL-R group also took significantly longer to complete the 6-m timed hop test relative to those in the control group (P < .05). No statistically significant differences were found in anthropometrics, knee extension or flexion strength, hamstring flexibility, hip abduction strength, or joint laxity between the MPFL-R and control groups. CONCLUSION: The current data indicate that MPFL-R generally restores functional symmetry, while subtle deficits in global power may remain after being released to full activity. Clinicians should ensure that athletes are fully rehabilitated before returning to sport after MPFL-R by emphasizing functional multijoint exercises.

Less efficient oculomotor performance is associated with increased incidence of head impacts in high school ice hockey.

OBJECTIVES: To evaluate associations between pre-season oculomotor performance on visual tracking tasks and in-season head impact incidence during high school boys ice hockey. DESIGN: Prospective observational study design. METHODS: Fifteen healthy high school aged male hockey athletes (M=16.50±1.17years) performed two 30s blocks each of a prosaccade and self-paced saccade task, and two trials each of a slow, medium, and fast smooth pursuit task (90°s-1; 180°s-1; 360°s-1) during the pre-season. Regular season in-game collision data were collected via helmet-mounted accelerometers. Simple linear regressions were used to examine relations between oculomotor performance measures and collision incidence at various impact thresholds. RESULTS: The variability of prosaccade latency was positively related to total collisions for the 20g force cutoff (p=0.046, adjusted R2=0.28). The average self-paced saccade velocity (p=0.020, adjusted R2=0.37) and variability of smooth pursuit gaze velocity (p=0.012, adjusted R2=0.47) were also positively associated with total collisions for the 50g force cutoff. CONCLUSIONS: These results provide preliminary evidence that less efficient oculomotor performance on three different oculomotor tasks is associated with increased incidence of head impacts during a competitive ice hockey season. The variability of prosaccade latency, the average self-paced saccade velocity and the variability of gaze velocity during predictable smooth pursuit all related to increased head impacts. Future work is needed to further understand player initiated collisions, but this is an important first step toward understanding strategies to reduce incidence of injury risk in ice hockey, and potentially contact sports more generally.

Injury initiates unfavourable weight gain and obesity markers in youth.

OBJECTIVE: The purpose of this study was to examine the association of knee injuries with subsequent changes in body mass index and body composition during maturation in young females. METHODS: A prospective longitudinal study design was employed to evaluate young females active in soccer or basketball (N=862). Participants who completed at least 1-year follow-up to provide consecutive annual measures of BMIZ and %fat were included in the study analysis to determine the effect of knee injuries on the trajectory of these obesity markers in youth. RESULTS: Of the 71 reported knee injuries, 12 (17%) occurred in athletes at the prepubertal stage, 24 (34%) in athletes at the pubertal stage, and 35 (49%) in postpubertal athletes. Controlling for the effects of maturation, female athletes who reported knee injury demonstrated a greater yearly increase in BMIZ (LS means and 95% CI for the injured group=0.039 (-0.012 to 0.089), for the non-injured group=-0.019 (-0.066 to 0.029), and group difference=0.057 (0.005 to 0.11), p=0.03) and in %body fat (LS means and 95% CI for the injured group=1.05 (0.45 to 1.65), for the non-injured group=0.22 (-0.21 to 0.064), and group difference=0.83 (0.21 to 1.45), p=0.009), compared to those without knee injuries. This indicates that the athletes with knee injuries will increase their body mass index percentile by up to 5 units more than someone of the same age without an injury, and in body fat by up to 1.5%, compared to their non-injured peers. CONCLUSIONS: The present findings indicate that knee injury during the growing years may be associated with unfavourable changes in body composition.

Sex-specific differences in the severity of symptoms and recovery rate following sports-related concussion in young athletes.

INTRODUCTION: While research on adult recovery from concussion indicates sex-specific symptoms and recovery rates, there is little existing data on younger patient populations. OBJECTIVE: To determine sex-specific differences in the severity of presenting symptoms and recovery rate between groups of young athletes who presented ≤ 7 or > 7 days after sports-related concussion. METHODS: This study was a retrospective review of athletes aged 9 to 17 years who were referred for evaluation of a sports-related concussion over a 24-month period. The study groups were divided by sex and post-injury presentation to the clinic at ≤ 7 days and > 7 days from the date of injury. Athletes with learning disabilities were excluded from the study and data analysis. Age, height, and weight were recorded for each subject. Each subject also reported their initial degree of confusion, amnesia, or loss of consciousness, and whether a helmet was worn when the injury was sustained. A 22-item post-concussion symptom score (SS) scale was completed by both groups on initial assessment (SS1) and follow-up visit (SS2). The recovery rate (SSR) was calculated as (SS2-SS1)/days between SS2 and SS1. Sex and group comparisons for SS1 and SSR were performed using 2 × 2 analysis of variance. A similar analysis was also performed for effects of sex on SS1 and SSR in patients who were not wearing a helmet. RESULTS: Thirty-seven athletes aged 15.0 ± 1.9 years were evaluated. Males, regardless of day of presentation, had a lower SS1 evaluation than females (15.8 vs 30.9; P < 0.05). Males without helmets did not differ from females without helmets, but this was not significantly different (14.1 vs 29.6; P = 0.1). There was not a significant difference in SS1 evaluation between the groups who presented at ≤ 7 or > 7 days. The overall mean SSR was -1.2/day, with no significant difference seen between groups or sex. There were no significant differences in degree of loss of consciousness, amnesia, confusion, or age between the sexes or groups. CONCLUSION: Whether presenting at ≤ 7 or > 7 days following a sports-related concussion, female athletes reported a higher SS1 evaluation. With SSR being similar between sexes, the current data suggest that young, female athletes may take longer to become symptom free following sports-related concussion. This information may be an important factor in returning a young athlete to sport after sports-related concussion.

Juvenile idiopathic arthritis and athletic participation: are we adequately preparing for sports integration?

Children with juvenile idiopathic arthritis (JIA) now have well-controlled disease due to improved therapies and management strategies. Children with JIA are more active than in the past and often participate in dynamic, high-loading sports. Standard measures of disease control include examination findings, laboratory values, and patient-directed surveys. However, these standards do not address the subtle deficits in biomechanics and neuromuscular control, which could place affected joints at higher risk for injury. Currently, there are limited evidence-based guidelines to structure conditioning recommendations as to the fitness and mechanics needed to provide safe integration into sports in this population; therefore, tools that objectively measure function with high accuracy and precision may be warranted. Previous work using 3-dimensional motion analysis demonstrated usefulness in guiding physical therapy treatment to correct these deficits. The use of a multidisciplinary team, including physical therapy, rheumatology, and sports medicine, is crucial for preparing these children to return to play. We suggest that the child transition into a sport preparatory-conditioning program to address any underlying deficits. A pediatric exercise specialist who is sensitive to the needs of this population can work with a physical therapist to then appropriately integrate the child safely into sport. Encouraging an active lifestyle is vital to the management of JIA and does not worsen the symptoms associated with childhood arthritis.