bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poster 228: Hamstring Muscle Injuries in Major League Soccer: An Analysis of Injury Rate, Associated Factors, and Return to Play
Authors: Gamsarian Vahram , Mirle Vikranth , Krishnan Aditya , Levine Zachary , Berlinberg Elyse , Giza Eric , Putukian Margot , Silvers Holly , Mandelbaum Bert , Group Forsythe 
Published: August 2023

Objectives: To examine (1) the rate and time to return to play (RTP) after hamstring muscle injury, (2) investigate the rate of reinjury after RTP, and (3) investigate conditions that are associated with increased severity of injury or increased time to RTP. Methods: MLS Injury Surveillance database was queried for all athletes with hamstring injuries from 2010-2021 were included and categorized by severity. A hamstring injury was defined as an incident that required medical attention and involved the biceps femoris, semimembranosus, or semitendinosus. Demographic characteristics and injury characteristics (setting of injury, activity during onset, severity, management, RTS, and re-injury) were collected and used for descriptive analysis. Results: A total of 2865 injuries were recorded between 2010 and 2021, from 1227 individual players. The average injured player age was 26.2 +/- 4.4 years, with an isolated biceps femoris injury (75.2%), occurring during a match (47.3%). The median time missed per injury was 11.0 days, with 28.2% of injuries resulting in no days missed, 52.7% were classified mild to moderate (4-28 days), and 19.2% severe (29-744 days). Average number of games missed, and practices missed per injury, were 1.3 +/- 2.3 and 4.0 +/- 7.5, respectively. Mean days missed increased significantly from 17.6 days for a hamstring injury occuring during 2010-2015 to 23.9 days for an injury occuring during 2016-2021 (p < 0.001). Overall hamstring re-injury rate was 52.4% (643), following a previously recorded index hamstring injury. Reinjury rate between 2010-2015 and 2016-2021 did not change significantly (50.2% vs. 51.6%, p = 0.4506). Factors associated with prolonged return to sport included acute injury onset (27.8 vs 21.9, p = 0.023), and match injury (24.9 vs 13.2, p <0.001). Position, field type, weather conditions, and in-game time of injury were not statistically significant. Conclusions: Between 2010 and 2021, hamstring injuries were one of the most common causes of missed time in MLS athletes. Acute onset and match injuries increased time to RTP by 27% (P = 0.023) and 89% (P < 0.0001), respectively. Furthermore, days missed increased for injuries during the 2010- 2015 and 2016-2021 seasons by 35.7% (p<0.001). The current findings emphasize the need for continued prevention and post-injury rehabilitation protocols and expectations. A reinjury rate as high as 50% likely contributes to longer rehabilitation timelines before RTP, however, further study is warranted given that reinjury rates did not decrease. [Table: see text]
Poster 241: Outcomes of Trochleoplasty for Recurrent Patellar Dislocation in Adolescents with Open Physes
Authors: Barras Laurel , Diduch David , Blanchard Neil 
Published: August 2023

Objectives: Patellofemoral dislocation, the most severe presentation on the spectrum of patellar instability, is most common in adolescent populations. Trochlear dysplasia is an integral component of the disorder, and procedures aimed at correcting instability by addressing this dysplasia are often necessary. A theoretical risk of injury to the distal femoral physis exists in these surgeries. At our institution, a thick-flap sulcus deepening technique is used to re-shape the trochlear groove. The risk of injury to the physis in this procedure is not clearly delineated in the current literature. We investigated the outcomes in adolescent patients undergoing this procedure, hypothesizing that patients with open distal femoral physes and less than 2 years of remaining growth can safely and successfully undergo thick-flap sulcus deepening trochleoplasty. Methods: Seventeen adolescents (21 knees) with open physes underwent thick-flap trochleoplasty at our institution. Preoperative radiographs were used to evaluate leg axis and patella alta. Preoperative MRI was used to determine trochlear dysplasia (sulcus depth, spur height, patellofemoral index) and tibial tuberosity to trochlear groove distance (TTTG) distance. Preoperative and postoperative AP and lateral radiographs were used to evaluate and compare the lateral distal femoral angle (LDFA) and Blumensaat’s angle (BA). Preoperative and postoperative IKDC and Kujala outcome scores were measured to evaluate clinical improvement. Results: Median age at time of operation was 14.9 years for girls and 15.5 for boys. Mean follow up was 5.4 years from surgery. At two-year follow up, growth plates were closed in all but one knee. No clinical differences to the leg length or alignment were appreciated. There was no statistically significant change in lateral distal femoral angle (mean change 0.74 degrees, p = 0.1074). There was a statistically significant change in Blumensaat’s angle (mean change 0.89 degrees, p = 0.0477). Mean Kujala score improved significantly from 60.19 preoperatively to 90.36 postoperatively, p= 0.0008. Mean IKDC score improved significantly from 59.37 preoperatively to 87.21 postoperatively, p = 0.00064. There was recurrent instability in one knee, requiring revision surgery with distal femur and Fulkerson osteotomies. Conclusions: Adolescent patients nearing skeletal maturity can safely and successfully undergo thick- flap sulcus deepening trochleoplasty for patellar instability resulting from trochlear dysplasia. At follow- up, there was no clinical evidence of growth disturbances, and postoperative imaging demonstrated less than 1 degree difference in LDFA and BA at skeletal maturity, which are unlikely to be of clinical significance. These findings should be interpreted very carefully, as specific patient selection, trochleoplasty expertise, and extreme caution are still necessary to prevent iatrogenic injury to the distal femoral physis.
Poster 260: Influence of Donor Demographics on Graft Survival following Knee Osteochondral Allograft Transplantation
Authors: Hevesi Mario , Wagner Kyle , Frazier Landon , Meeker Zachary , Kaiser Joshua , Yanke Adam , Cole Brian , Quigley Ryan 
Published: August 2023

Objectives: To evaluate whether donor and recipient factors such as donor age, sex mismatch, and time from death to graft implantation affect graft survival following knee osteochondral allograft (OCA) transplantation. Methods: Patients undergoing OCA transplantation in the knee from 2003-2016 were prospectively followed. Inclusion criteria consisted of primary OCA transplantation and minimum 2-year follow-up. Patient and donor demographic data were collected. Patients were evaluated for failure, defined as (1) subchondral collapse of the OCA as confirmed on postoperative MRI scans, or via second-look arthroscopy in the setting of persistent symptoms, (2) removal or revision of the primary OCA, or (3) conversion to arthroplasty. Multivariate cox proportional hazards modelling was utilized to evaluate associations between demographic variables and graft failure. Results: A total of 220 patients undergoing OCA transplantation met inclusion criteria and were followed for a mean of 5.9 ± 2.8 years (range: 2.0 – 16.3, Table 1). The most common concomitant procedure was meniscal allograft transplantation (Table 2). A mismatch in donor and recipient sex was present for significantly more female patients (65%) than male patients (10%, p < 0.001). The mean days from donor death until implantation was 24.1 days (range: 15 – 28). Thirty-nine patients (18%) met criteria for graft failure at a mean of 4.3 ± 3.2 years (Table 3). Log-rank testing did not determine a difference in survivability between those with a donor-recipient sex mismatch for female or male patients (P = .130 and .831, respectively). Upon multivariate cox regression, no association existed between donor-recipient sex mismatch or time from donor death to implantation with graft survival. Of note, increased donor age was associated with failure for female patients (P = .020) and trended towards significance in males (P = .166). Conclusions: OCA graft survival appears to be most strongly influenced by donor age. In contrast to previous historic data, no substantial survival difference was noted for sex mismatched donors and recipients. These data can help inform graft selection and outcome optimization following OCA. [Table: see text][Table: see text][Table: see text]
Poster 279: A NOVEL MAGNETIC RESONANCE IMAGING MARKER FOR ANTERIOR INSTABILITY OF THE LATERAL MENISCUS
Authors: Kinnard Matthew , Hoyt Benjamin , Murphy Timothy , Niu Emily 
Published: August 2023

Objectives: Anterior instability (AI) of the lateral meniscus is potentially debilitating in young patients. The lack of reliable and accurate Magnetic Resonance Imaging (MRI) findings limits the ability to preoperatively recognize AI. The goal of this study is to present a novel MRI finding (phantom sign) for AI of the lateral meniscus. Methods: Two independent blinded reviewers performed retrospective review of preoperative MRI for all patients who underwent lateral meniscus repair between 7/1/2019 and 3/31/2022 by a single fellowship trained surgeon. Positive phantom sign was defined as attenuated or decreased signal intensity along the anterior horn of the lateral meniscus on a single coronal cut at the anterior tibial insertion of the ACL. The lateral meniscus was also evaluated on coronal MRI for lateral extrusion, posterior displacement and posterior “megahorn” on sagittal cuts, and increased fluid signal adjacent to the anterior horn or a radial tear at the anterior root on axial cuts. Intraclass Pearson correlations were calculated for inter and intra-rater reliability in assessment for presence of pathology on MRI. Predictive ability of each imaging finding with at least good (ICC 0.6 or above) reliability was also evaluated by comparing MRI and documented intraoperative findings. Results: 55 patients with preoperative MRIs of arthroscopically repaired lateral meniscus tears were included. 21 patients (38.2%) were female with median age 15.0 years (range 10.5-16.0). 26 patients (47.3%) had a discoid lateral meniscus (DLM). Lateral meniscus AI was present on arthroscopy for 25 knees (45.5%) and among these 18 had concurrent DLM. Intraclass correlation was good for phantom sign (ICC 0.75, 95% CI 0.60-0.84), lateral extrusion (ICC 0.60 95% CI 0.41-0.75), posterior displacement (ICC 0.71, 95% CI 0.55-0.82), and posterior “megahorn” (ICC 0.76, 95% CI 0.62-0.85). On predictive analysis, phantom sign was 95.0% sensitive and 74.2% specific for lateral meniscal anterior instability. Posterior displacement and posterior megahorn were specific for anterior instability (both 93.3%) though with limited sensitivity (32.0% and 28.6%, respectively). Conclusions: Phantom sign is a reliable and sensitive MRI finding for AI, even in the absence of frank displacement of the meniscus, and should prompt thorough arthroscopic evaluation for this pathology. It may help guide treatment decision-making and preoperative planning, which may in turn improve patient outcomes and reduce complications of untreated anterior instability. [Table: see text][Table: see text][Table: see text]
Poster 291: Ultrasound-based patellar glide test: A new dynamic assessment of patellar instability
Authors: Hammerle Maria Virginia Velasquez , Rangaswamy Dharsini , Berkson Eric , Babu Ashwin , Tanaka Miho 
Published: August 2023

Objectives: Patellar instability can be difficult to assess due to the dynamic nature of this condition. While MRI and CT can demonstrate the morphology of the patellofemoral joint, the assessment of instability relies on dynamic testing. The patellar glide test is commonly utilized as a method of dynamic assessment on physical examination, yet precise quantification with this method remains difficult. Recently, cadaveric studies have demonstrated the utility of ultrasound in quantifying patellar translation. Therefore, our study aimed to apply the ultrasound-based patellar glide test to determine its utility in differentiating between knees with and without patellar instability in a clinical population. Methods: Patients with recurrent patellar instability were included in this study. Using a portable device, the ultrasound-based patellar glide test was performed with the knee in extension, and patellar position was visualized with and without a manual lateralizing force. The ultrasound probe was placed at the medial patellofemoral joint to visualize the relation of the medial patellar facet to the medial trochlea. Descriptive statistics were used to describe patellar position in the unloaded and loaded states, and patellar translation was calculated as the difference between the loaded and unloaded positions. Values were compared between symptomatic and asymptomatic knees. For each measurement of translation, receiver operating characteristic (ROC) curve analysis was performed. Youden’s J statistic was calculated to determine the optimal cutoff values to distinguish between asymptomatic vs symptomatic knees. Results: 50 knees from 25 patients (17F, 8M, mean age 26.9+/-9.4) were included in this study, of which 29 knees were unstable and 21 were stable and asymptomatic. When comparing symptomatic and asymptomatic knees, patellar position in the unloaded (4.6+/-2.8mm vs 3.8+/-2.3mm, p=0.277) and loaded states (1.1+/-3.24mm, 2.1+/-2.5mm, p=0.252) were not significantly different. Patellar translation was found to be significantly different between the symptomatic and asymptomatic states (3.5+/-2.2mm vs 1.7+/-1.5mm, p=0.002). ROC curve analysis demonstrated that patellar translation >3mm detected the presence of patellar instability with AUC 0.88 (95% CI 0.77, 0.98). 3mm translation was found to identify patellar instability with sensitivity 43.4%, specificity 95.2%, PPV 90.9%, and NPV 60.6%. Conclusions: The ultrasound-based patellar glide test was found to differentiate between symptomatic and asymptomatic knees in patients with patellar instability with high accuracy. Given the increasing availability of portable ultrasound devices and the need for quantification of patellar laxity, further studies are recommended to evaluate the role of this method of assessment in the diagnosis and management of patellar instability.
Poster 296: Incidence and Risk Factors for Contralateral Patellofemoral Instability
Authors: Duchman Kyle , Pennock Cole , an qiang , Westermann Robert 
Published: August 2023

Objectives: Background: Patellofemoral joint instability is common in young athletes and often requires surgical intervention. Incidence and risk factors for ipsilateral instability recurrence have been more discussed in the literature than contralateral instability events. Purpose: To evaluate the incidence and risk factors for contralateral patellofemoral instability in patients who have undergone patellar stabilization surgery. Methods: This retrospective study included 543 patients who had undergone medial patellofemoral ligament reconstruction and/or Fulkerson osteotomy as surgical management for lateral patellofemoral instability. The medical records of these patients were examined to evaluate the non-surgical knee. Available imaging of each affected knee was examined to evaluate for patella alta, skeletal maturity, trochlear dysplasia, tibial tubercle to trochlear groove (TT-TG) distance, and tibial tubercle to posterior collateral ligament (TT-PCL) distance. Demographic factors such as BMI, age, and sex were also examined. A second arm was done excluding patients with previous history of bilateral instability, assessing risk factors using the same methods. This yielded information about incidence and risk factors of “new onset” contralateral instability post-stabilization surgery. Results: Of the 543 patients examined, 205 (37.8%) had evidence of contralateral instability. Patella alta (OR, 2.4), skeletal immaturity (OR, 2.67), and younger age (p<0.0001) were associated with increased risk of bilateral instability. Sex, BMI, TT-TG distance, and TT-PCL distance, and trochlear dysplasia were not associated with increased risk of bilateral instability. In the second study, 63 out of 401 (15.71%) of patients had evidence of new onset contralateral instability post-surgery. Skeletal immaturity (OR, 3.65) was found to be associated with increased risk of instability. Conclusions: The incidence of bilateral patellofemoral instability was found to be 37.8%. Lower age, skeletal immaturity, and patella alta were found to be associated with increased risk of bilateral instability. Incidence of new-onset contralateral instability was found to be 15.71% and was only associated with skeletal immaturity.
Poster 299: Body mass index does not affect outcomes following isolated medial patellofemoral ligament reconstruction
Authors: Gibbs David , Kirven James , Abouljoud Moneer , Gonzalez Roberto , Ward Spencer , Flanigan David , Qin Charles , Magnussen Robert 
Published: August 2023

Objectives: Patellar instability may cause significant pain and disability and recurrent dislocations are often treated with reconstruction of the medial patellofemoral ligament (MPFL). Obesity is a known risk factor for complications following numerous surgical procedures, yet there exists a lack of data regarding the influence of body mass index (BMI) on outcomes following MPFL reconstruction. The purpose of this study was to evaluate complications and outcomes following isolated MPFL reconstruction in obese and non-obese patients. We hypothesized that patients with a BMI ≥ 30 would exhibit increased complication risk and worse patient-reported outcomes. Methods: A billing query identified all patients at one academic medical center who underwent isolated MPFL reconstruction over an 8 year period. Chart review extracted demographic, physical exam, radiographic, surgical, and complication data. Patients were contacted and outcomes were assessed with the Norwich Patellar Instability (NPI) score, Marx activity rating, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Complications and outcomes were compared based on the presence of a BMI ≥ 30 kg/m2. Results: A total of 161 patients who underwent isolated MPFL reconstruction were included. Of this cohort, there were115 with BMI < 30 and 46 with BMI ≥ 30. Early outcomes (time in brace, time to weight bearing) and postop complications (deep vein thrombosis, infection, pain, repeat dislocation/instability) were similar between groups (p>0.50). A total of 97 patients (60%) completed patient-reported outcomes at a mean of 5 years post-operative, with no differences noted in patient- reported outcomes based on BMI (Table). Conclusions: Obesity (defined as BMI ≥ 30) was not associated with increased complications of poorer patient- reported outcomes 5 years following isolated MPFL reconstruction. [Table: see text]
Poster 303: Radiographs Demonstrate Poor Interrater Reliability and Accuracy for Evaluation of Postoperative Healing for Osteochondral Allograft Transplants of the Knee
Authors: Dandu Navya , Elias Tristan , Allahabadi Sachin , Brusalis Christopher , Beals Corey , Trasolini Nicholas , Bodendorfer Blake , Haneberg Erik , Cole Brian , Yanke Adam 
Published: August 2023

Objectives: To evaluate the reliability of radiographs to evaluate healing of osteochondral allografts in the knee compared to CT scans as gold standard imaging. Methods: A retrospective review of prospectively enrolled patients who underwent osteochondral allograft transplantation for focal chondral defects of the knee was performed. At 6 months, all patients prospectively underwent CT scan of the knee. A retrospective review was performed to assess knee radiographs obtained in clinic at 3 and 6 months postoperatively. Three board-eligible orthopaedic sports fellows independently graded available radiographs while remaining blinded to the CT scan results. Separately, two board-eligible orthopaedic sports fellows graded CT scans utilizing the ACTOCA system, and their consensus measurements served as the gold standard for this study. Intraclass correlation (ICC) with a two-way random effects model and kappa coefficients were calculated for grades between the three raters. Results: Among the 44 grafts prospectively imaged, 13 (29.5%) grafts had radiographs at 3 months and 28 (63.6%) grafts had radiographs available for evaluation at 6 months. Among three graders, assessment of integration demonstrated low to moderate reliability (ICC: 0.25-0.41). Contrary to this, assessment of qualities such as graft sclerosis and cyst formation on radiographs demonstrated poor interrater reliability with inability to reject the null hypothesis that all grades were assigned randomly (p>0.05) (Table 1). At 6 months, in patients with large cysts (> 3 mm) on CT, only 2/18 (11%) were accurately detected on radiographs and 5/18 (27.8%) were underestimated as small cysts. In patients with small cysts (< 3 mm) on CT, only 4/42 grafts (9.5%) were accurately graded, and 3/42 (7.1%) evaluated grafts were overestimated to have large cysts (Figure 1). Among patients who had small or large cysts at 6 months, only 1/21 (4.8%) and 1/3 (33.3%) radiographic assessments detected this cystic change at 3 months, respectively. Patients with crossing trabeculae on CT were associated with a mean radiographic integration score of 81.0 ± 15.7, which was significantly greater than those with a discernible cleft < 3 mm (mean 68.7 ± 19.3, p=0.01). However, these groups were not significantly different than radiographic scores for grafts that had discernible clefts > 3 mm (80.0 ± 19.7, p>0.05). Among the 23 patients with a 6-month radiograph available, 4 required subsequent surgery for symptomatic failure. Three (75%) of these patients demonstrated large cyst formation on CT scan at 6 months. Conclusions: Evaluation of osteochondral allograft healing by radiographs alone may be inaccurate and associated with missed abnormalities such as cyst formation. [Table: see text]