Background: As regards anterior cruciate ligament (ACL) reconstruction (ACLR), graft diameter has been identified as a major predictor of failure in skeletally mature patients; however, this topic has not been well-studied in the higher risk pediatric population. Hamstring tendon autograft configuration can be adjusted to increase graft diameter, but tendon length must be adequate for ACLR. Historical parameters of expected tendon length have been variable, and no study has quantified pediatric ACL morphology with other osseous parameters. Purpose: To develop magnetic resonance imaging (MRI)–derived predictors of native ACL graft length in pediatric patients so as to enhance preoperative planning for graft preparation in this skeletally immature patient population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: MRI scans of 110 patients were included (64 girls, 46 boys; median age, 10 years; range, 1-13 years). Patients with musculoskeletal diseases or prior knee injuries were excluded. The following measurements were taken on MRI: ACL length; sagittal and coronal ACL inclination; intercondylar notch width and inclination; and femoral condyle depth and width. Associations between these measurements and patient sex and age were investigated. Univariate linear regression and multivariable regression models were created for each radiographic ACL measure to compare R 2. Results: Female ACL length was most strongly associated with the depth of the lateral femoral condyle as viewed in the sagittal plane ( R 2 = 0.65; P < .001). Other statistically significant covariates of interest included distal femoral condylar width, age, and coronal notch width ( P < .05). For males, the ACL length was most strongly associated with the distal femoral condyle width as viewed in the coronal plane ( R 2 = 0.70; P < .001). Other statistically significant covariates of interest for male ACL lengths were lateral femoral condyle depth, age, and coronal notch width ( P < .05). Conclusion: In pediatric populations, femoral condylar depth/width and patient age may be valuable in assessing ACL size and determining appropriate graft dimensions and configuration for ACLRs. The use of this information to optimize graft diameter may lower the rates of ACL graft failure in this high-risk group.

To better define the epidemiology of discoid meniscus by analyzing a large, national database for incidence rates and associations with demographic variables. MethodsFrom Optum's Clinformatics® Data Mart Database, incidence rates and proportions of reported racial categories -Asian, Black, Hispanic, and Caucasian -of diagnosed discoid meniscus cases (n = 198) in the study population of patients receiving arthroscopic meniscectomy or repair procedures (n = 60,042) were calculated and compared via chi-square tests to the total population. To control for age, sex, and socioeconomic factors such as income, multivariable logistic regression analysis was performed. ResultsProportions of discoid meniscus patients who were Asian, Black, Hispanic, or Caucasian were <6%, <7%, 15.7%, and 73.7%, respectively; proportions of each racial category in the study population were 2.2%, 7.4%, 9.9%, and 80.5%, respectively. Incidence rates per 1000 for these were 5.95, 2.92, 5.19, and 3.01, respectively. After adjusting for age, sex, and income, race was not a statistically significant predictor. Odds of a discoid meniscus diagnosis decreased by 6% for each increment in age (p <0.001) and by 40% if male (p <0.001) in our total study population. In patients <=20 years old, sex was not a significant risk factor. ConclusionsYounger age and female sex were identified as significant predictors for symptomatic discoid meniscus in the total study population. Unlike prior studies, this investigation did not show a significant association between this condition and race in the US, potentially increasing the diagnostic accuracy and estimated pretest probabilities for this condition based on patient demographics. What this study adds to existing knowledgeThis study provides new data on the role racial category plays in estimating the risk of having a symptomatic discoid meniscus requiring arthroscopic management, finding that it is unlikely to be a significant factor when controlling for other demographic variables. Furthermore, we report incidence statistics for this pathology in Black and Latinx populations, which so far have had little representation in peer-reviewed published literature on discoid meniscus epidemiology. In addition, this study suggests that age and sex possess statistically significant associations with a diagnosis of discoid meniscus requiring arthroscopic management, with the risk of diagnosis decreasing with age and increasing if female.

Background: Arthroscopy may be utilized for treatment of septic arthritis of the pediatric knee, with success reported in ages from 3 months to 12 years. There is limited data on the ability to arthroscopically assess articular structures and ensure adequate evaluation without arthrotomy. Hypothesis/Purpose: The purpose of this study is: (1) utilize arthroscopy in small cadaveric knees to improve qualitative and quantitative knowledge of pediatric articular structures and (2) to obtain pilot data for common procedures performed in pediatric patients Methods: Five small pediatric cadaveric specimens (1-4 years) underwent arthroscopy (2.7 mm Stryker arthroscope). Medial and lateral compartments were assessed for meniscus size/mobility/height, compartmental joint space, ACL insertion, patellar chondral height and length, and position of the medial patellofemoral ligament were recorded. Utilizing standard anterior medial and lateral portals, the ability to visualize the structures of the posteromedial and posterolateral compartments was recorded. Procedures pertinent to immature ACL reconstruction and meniscal repair (unstable discoid) were critically evaluated to provide source data for future work. Results: Prior to arthroscopy, all specimens underwent volume-assessed knee insufflation (average 11.4 cc normal saline). Arthroscopic visualization of the menisco-capsular attachment was possible posteromedially in 4/6, and posterolaterally in 5/6 knees. Qualitative arthroscopic relationships were similar to adult references; including patellar-trochlear articulation and lateral meniscal positional relationship to the ACL insertion (see Figure 1). The ACL center was within 2 mm of the posterior aspect of the anterior horn of the lateral meniscus in all specimens. The average height of the medial compartment space under valgus load was 1.5 mm (1 – 2 mm), and lateral space under varus was 2.2 mm (2-3 mm); further emphasizing the need for small joint instruments. The width of the medial and lateral menisci are noted in Table 1. All-inside meniscal devices designed for skeletally mature specimens should be used with caution (Figure 1). Traditionally described inside-out technique for immature ACL reconstruction with an iliotibial band demonstrated significant proximity of the passing device to the neurovascular bundle (Figure 1). Conclusion: The entirety of the small knee is assessable via standard diagnostic arthroscopy, when a 2.7mm arthroscope is utilized. These findings suggest that intra-articular pathology can be reliably identified utilizing this surgical technique. However, the ability to work on the infant meniscus and cartilage with standard arthroscopic instruments is likely limited given the constraints of joint height. [Table: see text][Figure: see text]

Background: Discoid meniscus epidemiology remains poorly defined for race and sex, in part, due to limitations of retrospective studies and small case series. A better understanding of epidemiology may improve clinical care and diagnostic precision. Purpose: Our purpose is to better define the epidemiology of discoid meniscus by analyzing a large, national database for incidence rates by sex and race. Methods: Analysis was conducted on the national-scale Clinformatics Data Mart Database by Optum. Proportions of the database’s racial categories (Asian, Black, Hispanic, White, and Unknown) in the total population of diagnosed discoid meniscus cases (n = 1,006) were calculated and compared via chi-squared tests to the total database population (n = 65,759,970). This analysis was repeated for the population of patients who received knee arthroscopies (81,205). Incidence rates were calculated from these populations as well. Finally, a multivariable logistic regression analysis based on the population of arthroscopy-receiving patients was performed to control for age, reported gender, and income. Results: Proportions of Asian, Black, Hispanic, and White racial categories in the discoid meniscus group were 5.7%, 7.3%, 20.6%, 66.4%, respectively; the proportions of each racial category in the total population were 5.2%, 10.3%, 13.5%, 71.0%, respectively. Incidence rates (per 10,000) for these groups in the arthroscopy population were 72.9, 25.6, 49.2, 25.6, respectively. Our logistic regression model indicated that race was not a statistically significant predictor for our dataset after income adjusting. Adjusting for other covariates, the odds of a discoid meniscus diagnosis decreased by 6% for each increase in age (p < 0.001) and were 41% lower for males compared to females (p < 0.001). Conclusion: Prior studies have suggested that race (Asian and Hispanic, is a predictor of higher incidence of discoid meniscus – this study did not show a difference in incidence based upon race. Patient sex and age was identified as significant predictors for discoid meniscus, and increasing age showed a decreasing incidence of this condition. This study’s analysis of a large, national claims database allows for a comprehensive epidemiological study on this topic, offering proportions and incidence rates by race appropriate for application to the US population. Its conclusions promote patient sex and age as significant predictors and question the beliefs on race-associated incidence often based on comparing results from the corpus of single-site cohort studies. Tables/Figures: [Table: see text]