Background: Bone bruise characteristics after anterior cruciate ligament (ACL) injury have been correlated with the level of joint derangement in adults. However, the literature lacks information about younger patients, whose higher ligamentous laxity may lead to different lesion patterns. Purpose: To investigate the prevalence, size, location, and role of bone bruise associated with ACL rupture in the pediatric population. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Knee magnetic resonance imaging scans (MRIs) of patients aged 8 to 16 years with ACL tears from 2010 to 2018 were selected from the institution database. Inclusion criteria were open or partially open physes, less than 90 days between trauma and MRI, and no history of injury or surgery. Presence, localization, and size of bone bruise were analyzed by 2 blinded researchers and scored with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) bone bruise subscale. Ligamentous, cartilaginous, meniscal, and other lesions were documented. Results: Of the 78 pediatric patients selected from the database, 54 (69%) had bone bruise. The mean area of bone bruise was larger in males than in females (femur, 3.8 ± 2.8 vs 2.2 ± 1.4 cm2, respectively, P = .006; tibia, 2.6 ± 1.6 vs 1.5 ± 0.8 cm2, respectively, P = .007). The subregions most affected by bone bruise were the lateral posterior tibia and the lateral central femur (in 83% and 80% of the knees affected, respectively). A low correlation was found between age and bone bruise area (biggest areas r = 0.30, P = .03, and sum of areas r = 0.27, P = .04), but no correlation was found between age and WORMS (femur, r = −0.03, P = .85; tibia, r = −0.04, P = .76). The injuries most associated with bone bruise were 23 meniscal lesions (43%), 10 lesions of other ligaments (19.0%), 2 cartilage lesions (3.7%), and 2 patellar fractures (3.7%). Conclusion: The prevalence of bone bruises in pediatric patients with ACL tears is high, although it seems slightly lower than the prevalence documented in adults but with similar localization. The area and the distribution pattern of bone bruises are similar among different ages. The pediatric patients had a lower presence of cartilage and meniscal lesions compared with that reported in adults, which suggests a different effect of this trauma on the knee of pediatric patients.

Background Health care workers (HCWs) are at high risk of contracting an infection by SARS CoV-2 and thus they are a priority for vaccination. We hereby aim to investigate whether the risk of severe and moderate systemic symptoms (MSS) after vaccination is higher in HCWs with a history of previous COVID-19. Methods An online questionnaire was offered to the cohort all HCWs undergoing anti-SARS CoV-2 mRNA BNT162b2 vaccination between January 4th and February 9th 2021 in two large tertiary hospitals (ASST Santi Paolo and Carlo) in Milan, Italy. Previous SARS-CoV-2 infection/COVID-19 was recorded. Local and systemic symptoms after each of the two doses were reported. MSS were those either interfering with daily activities or resulting in time off-work. Factors associated to MSS were identified by logistic regression. Findings 3,078 HCW were included. Previous SARS-CoV-2 infection/COVID-19 occurred in 396 subjects (12·9%). 59·6% suffered from ≥ 1 local or systemic symptom after the first and 73·4% after the second dose. MSS occurred in 6·3% of cases (14·4% with previous vs 5·1% with no COVID-19 p <0·001) and in 28·3% (24·5% in COVID-19 vs 28·3% no COVID, p = 0·074) after the first and second dose, respectively. Subjects already experiencing COVID-19 had an independent 3-fold higher risk of MSS after the first and a 30% lower risk after the second dose. No severe adverse events were reported. Interpretation Our data confirm in a real-world setting, the lack of severe adverse events and the short duration of reactogenicity in already infected HCWs. Possible differences in immune reactivity are drivers of MSS among this group of HCWs, as well as among females and younger individuals. Funding None.

Background Careful pre- and post-operative management can allow surgeons to perform outpatient TKA, making this a more affordable procedure. The aim of the present meta-analysis is to compare outpatient and inpatient TKA. Methods A systematic search of the literature was performed in July 2020 on PubMed, Web of Science, Cochrane library, and on the grey literature databases. The papers collected were used for a meta-analysis comparing outpatient and inpatient TKA in terms of complication and readmission rates. Risk of bias and quality of evidence were defined according to Cochrane guidelines. Results The literature search resulted in 4107 articles; of these, 8 articles were used for the meta-analysis. A total of 212,632 patients were included, 6607 of whom were TKA outpatients. The overall complication rate for outpatient TKAs was 16.1%, while inpatient TKAs had an overall lower complication rate of 10.5% (p = 0.003). The readmission rate was 4.9% in outpatient TKAs and 5.9% in inpatient TKAs. Only 3 studies reported the number of deaths, which accounted for 0%. The included studies presented a moderate risk of bias, and according to GRADE guidelines, the level of evidence for complications and readmissions was very low. Conclusions This meta-analysis documented that outpatient TKA led to an increased number of complications although there were no differences in the number of readmissions. However, future high-level studies are needed to confirm results and indications for the outpatient approach, since the studies currently available have a moderate risk of bias and a very low quality of evidence.

Background: There is no consensus about the safety of outpatient total hip arthroplasty (THA). Therefore, the purpose of this meta-analysis was to quantitatively evaluate and compare outpatient and inpatient THA studies in terms of complication and readmission rates. Methods: A systematic search of the literature was performed on 26 July 2019 on PubMed, Web of Science, Cochrane library, and on the grey literature databases. The papers thus collected were used for a meta-analysis comparing outpatient and inpatient THA in terms of complication and readmission rates. Risk of bias and quality of evidence were defined according to Cochrane guidelines. The PRISMA guidelines were used to determine which papers to include in this study. Results: The literature search resulted in 2317 articles; of these, 8 articles were used for the meta-analysis. A total of 66,971 patients were included, of which 1428 were THA outpatients. The overall complication rate for outpatient THAs was 3.0%, while inpatient THAs had an overall complication rate of 4.7%. The readmission rate was 1.4% in outpatient THAs and 3.0% in inpatient THAs. Only 6 studies reported the number of deaths, which ranged from 0% to 0.01%. The included studies present a moderate risk of bias and, according to GRADE guidelines, the level of evidence for complications and readmissions is very low. Conclusions: This meta-analysis documented that outpatient THA is a feasible approach since it does not increase complications or readmissions with respect to inpatient THA, but the available studies present a moderate risk of bias and the quality of evidence of these findings is very low. Future high-level studies are needed to confirm results and indications for outpatient THA.