Supplemental Material: Ultrahigh-temperature granulite-facies metamorphism and exhumation of deep crust in a migmatite dome during late- to post-orogenic collapse and extension in the central Adirondack Highlands (New York, USA)

<div>Text S1: Supplemental text. Figure S1: Cathodoluminescence images for all analyzed zircon grains. Figure S2: REE spider plots for zircon. Figure S3: Tukey honestly significant difference (HSD) for the timing of anatexis. Table S1: Cathodoluminescence images for all analyzed zircon grains. Table S2. Grossular content of garnet used to calculate the 95% confidence intervals for isopleth modeling in Figure 13. <br></div>

Supplemental Material: Ultrahigh-temperature granulite-facies metamorphism and exhumation of deep crust in a migmatite dome during late- to post-orogenic collapse and extension in the central Adirondack Highlands (New York, USA)

<div>Text S1: Supplemental text. Figure S1: Cathodoluminescence images for all analyzed zircon grains. Figure S2: REE spider plots for zircon. Figure S3: Tukey honestly significant difference (HSD) for the timing of anatexis. Table S1: Cathodoluminescence images for all analyzed zircon grains. Table S2. Grossular content of garnet used to calculate the 95% confidence intervals for isopleth modeling in Figure 13. <br></div>

Supplemental Material: Ultrahigh-temperature granulite-facies metamorphism and exhumation of deep crust in a migmatite dome during late- to post-orogenic collapse and extension in the central Adirondack Highlands (New York, USA)

<div>Text S1: Supplemental text. Figure S1: Cathodoluminescence images for all analyzed zircon grains. Figure S2: REE spider plots for zircon. Figure S3: Tukey honestly significant difference (HSD) for the timing of anatexis. Table S1: Cathodoluminescence images for all analyzed zircon grains. Table S2. Grossular content of garnet used to calculate the 95% confidence intervals for isopleth modeling in Figure 13. <br></div>

AEROBIC EXERCISE VOLUME, NOT PRESCRIPTION, INFLUENCES POST-CONCUSSION SYMPTOMS: A RANDOMIZED CLINICAL TRIAL

Background: Current recommendations for sport-related concussion uniformly emphasize the importance of physical activity. However, specifics of this recommendation remain vague and do not account for an exercise dosage or compliance. Purposes: First, we examined if an 8-week individualized sub-symptom threshold aerobic exercise prescription, initiated within the first two weeks of concussion, alleviates symptom severity or affects the amount of exercise performed during the study. Second, we examined whether prescription adherence, rather than randomized group assignment, reflects the actual impact of aerobic exercise in post-concussion recovery. Methods: For this single-site prospective randomized clinical trial, participants completed an aerobic exercise test within 14 days of injury, and were randomized to an individualized aerobic exercise program or standard-of-care, and returned for assessments 1 month and 2 months after the initial visit (Table 1). The aerobic exercise group was instructed to exercise 5 days/week, 20 minutes/day, at a target heart rate based on an exercise test at the initial visit. Participants reported their symptom exercise volume each week over the 8-week study period, and reported symptoms at each study visit (initial, 1 month, 2 month). Results: Initial symptom severity was not different between randomized groups (Figure 1A), and no significant differences in symptom severity were found at the 4-week (Figure 1B) or 8-week (Figure 1C) assessment. In addition, there was no significant differences between groups for average weekly exercise volume during the first four weeks (Figure 2A) or second four weeks (Figure 2B) of the study. During the first four weeks of the study, 65% (n=11/17) of the exercise intervention participants were compliant with their exercise recommendation (≥100 min/week), compared to 45% (n=9/20) of the standard-of-care group (p=0.33). During the second four weeks of the study, 71% (n=12/17) of the exercise prescription group exercised ≥100 min/week, compared to 55% (n=11/20) of the standard-of-care group (p=0.50). When grouped by exercise volume, the group who exercised ≥100 minutes/week during the first month of the study reported significantly lower symptom severity scores than those who exercised <100 minutes/week (Figure 3B), despite similar initial symptom severity scores (Figure 3A). Conclusion: Participant randomization within 14 days of concussion did not lead to a significant reduction in symptoms, or greater exercise volume. Given that greater exercise volume was associated with lower symptoms after one month of the study, researchers and clinicians should pay particular attention to adherence to aerobic exercise programs for the treatment of concussion. [Table: see text][Figure: see text][Figure: see text][Figure: see text]

DELAY TO ACL RECONSTRUCTION IN PEDIATRIC AND ADOLESCENT PATIENTS IS ASSOCIATED WITH A LINEAR INCREASE IN THE RISK OF MEDIAL MENISCAL TEARS

Background: Anterior cruciate ligament (ACL) tears are frequently associated with meniscal tears. Previous studies have shown that secondary meniscal tears—occurring after the initial ACL injury—are associated with greater delays from injury to ACL reconstruction (ACLR), but frequently use dichotomous categories of acute versus delayed ACLR. Purpose: As meniscal damage is likely accrued constantly over time, we investigated the variability of concurrent meniscal injuries as a function of time from injury to ACLR in a pediatric and adolescent population. Methods: We performed a retrospective review of all patients ≤18 years who underwent an ACLR between 2014 and 2018 at one of two tertiary academic hospitals. Outliers were excluded if time from injury to ACLR was greater than 78 weeks. Records were reviewed to assess patients’ dates of injury and surgery. The prevalence of concurrent medial and/or lateral meniscal injury was evaluated at the time of surgery for each patient. Adjusted relative risks (ARRs) of meniscal injury were calculated using Poisson regression models adjusted for age, sex, and body-mass index. Logistic regression was used to model the predicted probability of medial meniscal tears. Results: 546 patients met inclusion criteria. The mean age of participants was 15.3 years (S.D., 1.6), and 277 (50.7%) patients were male. Overall, 344 (63.0%) patients had a meniscal tear. 169 (49.1%) tears occurred at the medial meniscus, and 257 (74.7%) occurred at the lateral meniscus (Table 1). Compared to females, males had a greater risk of lateral meniscal injury (ARR, 1.46; 95% CI, 1.20-1.77) but not medial meniscal injury (ARR, 1.01; 95% CI, 0.77-1.31) (Figure 1). When considering all meniscal tears, time from injury to ACLR was not associated with increased risk of a tear (ARR, 1.01; 95% CI, 1.00-1.01). However, for medial meniscal tears, there was a significant association between time from injury to ACLR, in weeks, and meniscal tears (ARR, 1.02; 95% CI, 1.01-1.03, P = 0.003). A ten-week delay was associated with a 20% increased risk of medial meniscal injury (Figure 2). Conclusion: In pediatric and adolescent ACLR patients, the risk of any meniscal injury was not associated with delay from injury to surgery. However, the risk of medial meniscal injury increased by 2% each week from injury to surgery. [Table: see text][Figure: see text][Figure: see text]

Hybrid Transtibial Femoral Preparation for Transphyseal Anterior Cruciate Ligament Reconstruction: A Radiographic Comparison to Transtibial and Anteromedial Portal Techniques

Background: Transphyseal anterior cruciate ligament (ACL) reconstruction remains the most commonly used technique for pubescent patients. The principles of creating vertical and central femoral tunnels are well accepted to minimize physeal area of injury and are typically accomplished with a transtibial (TT) technique. This, however, may come at the expense of a non-anatomic tunnel. The hybrid transtibial (HTT) technique offers the potential of combining an anatomic femoral position with tunnel geometry similar to the TT technique but has never been assessed in a clinical cohort. Hypothesis/Purpose: We hypothesized that tunnels created by a HTT technique would be similar in orientation and physeal location to TT tunnels, but significantly more vertical and central than tunnels created with an anteromedial portal (AM). Methods: We retrospectively screened all ACL reconstructions performed in children aged 10 to 16 years, at our institution between 2013 to 2019, with the requirements of having a transphyseal reconstruction and an available post-operative radiographs. Radiographs were then assessed for the coronal femoral tunnel angle (FTA), as well as the location of the tunnel-physis penetration on the AP (LTAP) and lateral (LTL) views. Physeal lesion surface area was calculated. Data were compared between the three groups using ANOVA. Results: Forty-seven patients met eligibility criteria with 9 TT, 18 AM, and 20 HTT patients. Mean patient age was 14.3 +/- 1.2 years. The FTA was significantly more vertical in the TT (60.7o +/-7.2) and HTT (54.4o +/- 5.7) groups as compared to the AM group (48.8o +/- 5.9); p = 0.0037 and p = 0.02 respectively. There was no significant difference between the TT and HTT groups ( p = 0.066). The LTAP was not significantly different between groups (p = 0.097). The LTL demonstrated that the HTT tunnels penetrated the physis at a more central location in the sagittal plane (28.9% +/- 4.8%) than the AM tunnels (20.0% +/- 5.1%, p = 0.00002), but was statistically indistinguishable from the TT (24.4%+/- 4.0%, p= 0.066) tunnels. Conclusion: The hybrid transtibial technique presents an option for transphyseal ACL reconstruction, with femoral tunnel obliquity and estimated physeal disruption similar to the TT technique, significantly less than the AM technique. The HTT also results in the most central physeal perforation of all techniques, predominantly in the sagittal plane. With the known ability of the HTT technique to recreate an anatomic femoral footprint, this may represent the “best of both worlds” for transphyseal ACL reconstruction. Tables/Figures: [Figure: see text][Figure: see text][Figure: see text][Figure: see text]

ISOKINETIC STRENGTH IS COMPARABLE AMONG ADOLESCENT PATIENTS WHO HAD EITHER A SINGLE INJECTION FEMORAL NERVE BLOCK OR CONTINUOUS FEMORAL NERVE CATHETER DURING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Background: Single injection femoral nerve blocks or continuous femoral nerve catheters are commonly used during anterior cruciate ligament reconstruction (ACLR). However, both single injection and continuous femoral nerve catheters have been associated with decreased quadriceps strength and function up to 6 months postoperative compared to no regional anesthesia Purpose/Hypothesis: We compared isokinetic limb asymmetry 5-10 months post-surgery between patients who received either single injection or continuous femoral nerve block during ACLR. We also assessed patient characteristics potentially associated with strength deficits. We hypothesized that patients with continuous femoral nerve catheters would demonstrate decreased quadriceps function due to increased local anesthetic. Methods: We reviewed medical records of patients ages 10-19 years who completed isokinetic testing 5-10 months following quadricep tendon ACLR by a single surgeon. Patients were excluded for previous lower limb surgery. We grouped patients based on whether they received a single injection femoral nerve block (FNB group) or a continuous femoral nerve catheter (FNC group) intraoperatively. Using isokinetic data at 60, 180, and 300 degrees per second, we calculated maximum torque percent deficit of the involved compared to the uninvolved leg, as well as compared peak torque extensor and flexor deficits (% difference between operative/non-operative sides) between groups. Results: Sixty-two patients were included: 50 who received FNC and 12 who received FNB (Table 1). There were no significant differences between continuous femoral nerve block and single-shot femoral nerve block groups for extensor deficits at any speed (Figure 1) or for flexor deficits at any speed (Figure 2). At 60 degrees/s (p=0.006) and 180 degrees/s (p=0.017), longer time since surgery was associated with smaller extensor deficits (Table 2). At 180 degrees/s (p=0.008) older age was associated with greater extensor deficits (Table 2). At 60 degrees/s (p=0.017) skeletal maturity was associated with greater extensor deficits (Table 2). At all speeds, an injured dominant limb was associated with smaller flexor deficits (Table 3). Older age was associated with greater flexor deficits at 60 deg/s (Table 3). Conclusion: No apparent significant isokinetic strength differences were found between groups 5-10 months postoperatively. Longer time from surgery was significantly associated with decreased extensor deficits among both groups at slower isokinetic test speeds. Our data suggest increased isokinetic strength recovery over the 5-10-month timeframe. The surgeon, anesthesia team, and patient should choose the pain management protocol based on resource and patient factors. Tables and Figures: [Table: see text][Table: see text][Table: see text][Figure: see text][Figure: see text]

Trends in Adolescent Hip Arthroscopy From the PHIS Database: 2008 to 2018

Background: Previous studies have suggested that hip arthroscopy has been performed with increasing frequency. Few studies have examined this trend in the adolescent population. Purpose: The purpose of this study was to evaluate the trend in the frequency of hip arthroscopy in adolescents standardized by total orthopaedic surgeries in adolescents at pediatric hospitals in the United States. Methods: The Pediatric Health Information System (PHIS) database was queried for patients aged 10 to 19 years who underwent orthopaedic surgery at any of the PHIS-participating hospitals from 2008 to 2018. The subgroup of patients in this age cohort who underwent hip arthroscopy was identified using Current Procedural Terminology (CPT) procedure codes. The yearly rate was expressed as the number of hip arthroscopies per 1000 orthopaedic surgeries. A linear model was used to fit the data and illustrate the relative trend. Results: A total of 432309 orthopaedic surgeries including 9491 hip arthroscopies were performed for patients 10 to 19 years of age. Hip arthroscopies were performed at a yearly rate of 22 per 1000 orthopaedic surgeries. Over the 10-year period, the number of hip arthroscopies increased 6.2-fold, whereas the number of orthopaedic procedures increased 1.6-fold. There was a 3.9-fold increase in hip arthroscopies relative to total orthopaedic surgeries. Conclusion: The number of hip arthroscopic procedures in adolescent patients has increased by 3.9-fold times relative to total orthopaedic surgeries in adolescents over a 10-year span. This finding mirrors the trends in the adult population over similar time periods. This may be due to increasing participation in sports in the adolescent population as well as a better understanding of the diagnosis and treatment of femoroacetabular impingement and other sports-related hip pathologies. [Table: see text][Figure: see text]

CHANGES IN SUPERIOR DISPLACEMENT, ANGULATION, AND SHORTENING IN THE EARLY PHASE OF HEALING FOR COMPLETELY DISPLACED MIDSHAFT CLAVICLE FRACTURES IN ADOLESCENTS: RESULTS FROM A PROSPECTIVE, MULTICENTER STUDY

Background: Progressive displacement of diaphyseal clavicle fractures has been observed in adult patients, at times necessitating a change from non-operative to operative treatment. Whether this occurs in adolescent patients has not been well investigated. Purpose: The purpose of this study was to assess the rate and extent of progressive clavicle fracture displacement in adolescent patients following injury and during the early stages of healing. Methods: This was an IRB approved multi-center study evaluating prospective data that had previously been collected as part of a larger study evaluating the functional outcomes of adolescent clavicle fractures. A consecutive series of completely displaced diaphyseal clavicle fractures in patients age 10-18 years treated at one of three tertiary care pediatric trauma centers were included; all of which had standardized imaging within 2 weeks of the date of injury and throughout the course of healing (5-20 weeks post-injury). Measurements of clavicle shortening, superior displacement, and angulation were performed using validated techniques. Progressive displacement and/or interval improvement in fracture alignment were noted, as well as the subsequent need for surgical intervention. Patient demographic and radiographic parameters were assessed as possible risk factors for interval displacement. Results: One hundred patients met the inclusion criteria. The mean shortening, superior displacement, and angulation at the time of injury were 24 mm, 15 mm, and 7°, respectively. At a mean of 10 weeks post-injury, the fracture alignment improved across all three measurements for the overall cohort, with mean improvements in shortening of 15%, superior displacement of 15%, and angulation of 21% (Figures 1,2,3) Using a clinical threshold of a change in shortening or displacement of 10 mm or angulation of 10 degrees, 21% of fractures improved, 4% worsened, and 75% remain unchanged. Patients with more severe fractures were more likely to have improved alignment than less displaced fractures (p<0.001). No patient underwent surgical intervention for progressive displacement. Conclusions: Significant early improvements in fracture alignment were observed in a substantial percentage of adolescent patients with completely displaced clavicle fractures. Among the most severely displaced fractures, a 20% improvement in shortening and 50% improvement in angulation was identified. In 4% of cases, increased displacement was observed, but this tended to be mild, and in no cases did it prompt surgical intervention. This finding indicates that the true final deformity after an adolescent clavicle fracture is commonly less than that present at the time of injury. Figures: [Figure: see text][Figure: see text][Figure: see text]

ANXIETY, FEAR, AND MOVEMENT FOLLOWING SPORTS-RELATED CONCUSSION: HOW DOES KINESIOPHOBIA CORRELATE TO SYMPTOMS AND REACTION TIME?

Background: Fear of pain with movement, also known as kinesiophobia, has been widely studied in various musculoskeletal injuries, yet little is known about its relationship to concussion. Given that concussion can negatively affect neuromuscular control and anxiety, re-integration into sports following a concussion may be associated with kinesiophobia. Hypothesis/Purpose: Our primary purpose was to examine kinesiophobia, among youth athletes with concussion compared to uninjured controls. Secondarily, we sought to examine correlations between kinesiophobia with concussion symptom severity and reaction time. We hypothesized adolescents with concussion would demonstrate greater kinesiophobia compared to controls. Additionally, we hypothesized that greater kinesiophobia would be correlated with higher symptom severity and slower reaction times. Methods: We conducted a repeated measures study of 48 youth athletes. Participants were evaluated at two time points. The concussion group was assessed within 14 days of injury and once cleared for return to play (RTP) by physician. The control group was tested initially and again approximately 28 days later. Participants completed Tampa Scale of Kinesiophobia (TSK), Post-Concussion Symptom Inventory (PCSI), and clinical reaction time (CRT) assessments. We compared mean group differences and assessed the correlation of TSK with PCSI and CRT, at each assessment. Results: We included 26 participants with a concussion and 16 controls (Table 1). The concussion group reported significantly greater TSK scores at the initial assessment (38.0±5.6 vs. 29.3±6.9; p<0.001; Figure 1) and a significantly greater proportion of “high” TSK scores (>36) compared to controls (69% vs. 19%; p = 0.004; Table 1). At the follow-up assessment, there were no significant between group differences in TSK scores (32.8±7.0 vs. 30.4±7.5; p=0.35; Figure 1), or the proportion of “high” TSK scores (38% vs. 25%; p=0.51; Figure 1). TSK scores were significantly and moderately correlated with PCSI for the concussion group at both assessments (r=0.53; p=0.006 at visit 1, r=0.47; p=0.01 at visit 2; Figure 2), but not for controls (Figure 2). Furthermore, TSK scores were significantly and moderately correlated with CRT for the concussion group (r=0.50; p=0.01; Figure 2), but not controls (r= -0.26; p=0.37; Figure 2) at the follow-up assessment. Conclusion: Adolescents recovering from concussion commonly reported high kinesiophobia at initial concussion assessment, while many no longer reported high kinesiophobia when given RTP clearance. Furthermore, kinesiophobia was significantly correlated with self-reported concussion symptoms and clinical reaction time scores. The correlation between kinesiophobia and reaction time suggests a perception-behavior relationship with post-concussion movement deficits may exist. Tables/Figures: [Table: see text][Figure: see text][Figure: see text]