Bruise Patterns Research Articles

Effect of the Material Properties and Knee Position to the Bone Bruise Pattern in Skeletally Mature and Immature Subjects.

A bone bruise is generated by a bony collision that could occur when the ACL is injured, and its pattern supposedly depends on the injury mechanism and level of skeletal maturity. The objective of this study was to determine the effect of material properties and knee position on the bone bruise pattern in skeletally mature and immature subjects using finite element analysis. Finite element models were created from an MR image in the sagittal plane of a skeletally mature and immature male subject. The femur and tibia were collided at 2 m/s to simulate the impact and determine the maximum principal stress. The analysis was performed at 15, 30 and 45 degrees of knee flexion, and neutral, 10 mm anterior and posterior translated position at each flexion angle. Although high stress was distributed toward the metaphysis area in the mature model, the stress did not cross the growth plate in the immature model. The size of the stress area was larger in the mature model than those in the immature model. The location of the stress area was dependent on the joint position as well as Young's modulus of cartilage and trabecular bone. Thus, the bone bruise pattern was affected by the knee position and tissue quality. In conclusion, although the bone bruise distribution was generally called footprint of the injury, the combined evaluation of the quality of the structure and the bone bruise distribution is necessary for properly diagnosing tissue injury based on the MR imaging.

Investigating the Bone Bruise Patterns in Pediatric Patients With Contact and Noncontact Acute Anterior Cruciate Ligament Tears: A Multicenter Study

Background: In adults with anterior cruciate ligament (ACL) tears, bone bruises on magnetic resonance imaging (MRI) scans provide insight into the underlying mechanism of injury. There is a paucity of literature that has investigated these relationships in children with ACL tears. Purpose: To examine and compare the number and location of bone bruises between contact and noncontact ACL tears in pediatric patients. Study Design: Cohort study; Level of evidence, 3. Methods: Boys ≤14 years and girls ≤12 years of age who underwent primary ACL reconstruction surgery between 2018 and 2022 were identified at 3 separate institutions. Eligibility criteria required detailed documentation of the mechanism of injury and MRI performed within 30 days of the initial ACL tear. Patients with congenital lower extremity abnormalities, concomitant fractures, injuries to the posterolateral corner and/or posterior cruciate ligament, previous ipsilateral knee injuries or surgeries, or closed physes evident on MRI scans were excluded. Patients were stratified into 2 groups based on a contact or noncontact mechanism of injury. Preoperative MRI scans were retrospectively reviewed for the presence of bone bruises in the coronal and sagittal planes using fat-suppressed T2-weighted images and a grid-based mapping technique of the tibiofemoral joint. Results: A total of 109 patients were included, with 76 (69.7%) patients sustaining noncontact injuries and 33 (30.3%) patients sustaining contact injuries. There were no significant differences between the contact and noncontact groups in terms of age (11.8 ± 2.0 vs 12.4 ± 1.3 years; P = .12), male sex (90.9% vs 88.2%; P > .99), time from initial injury to MRI (10.3 ± 8.1 vs 10.4 ± 8.9 days; P = .84), the presence of a concomitant medial meniscus tear (18.2% vs 14.5%; P = .62) or lateral meniscus tear (69.7% vs 52.6%; P = .097), and sport-related injuries (82.9% vs 81.8%; P = .89). No significant differences were observed in the frequency of combined lateral tibiofemoral (lateral femoral condyle + lateral tibial plateau) bone bruises (87.9% contact vs 78.9% noncontact; P = .41) or combined medial tibiofemoral (medial femoral condyle [MFC] + medial tibial plateau) bone bruises (54.5% contact vs 35.5% noncontact; P = .064). Patients with contact ACL tears were significantly more likely to have centrally located MFC bruising (odds ratio, 4.3; 95% CI, 1.6-11; P = .0038) and less likely to have bruising on the anterior aspect of the lateral tibial plateau (odds ratio, 0.27; 95% CI, 0.097-0.76; P = .013). Conclusion: Children with contact ACL tears were 4 times more likely to present with centrally located MFC bone bruises on preoperative MRI scans compared with children who sustained noncontact ACL tears. Future studies should investigate the relationship between these bone bruise patterns and the potential risk of articular cartilage damage in pediatric patients with contact ACL tears.

A Systematic Review of Bone Bruise Patterns following Acute Anterior Cruciate Ligament Tears: Insights into the Mechanism of Injury.

(1) Background: The purpose of this systematic review was to determine the prevalence of bone bruises in patients with anterior cruciate ligament (ACL) injuries and the location of the bruises relative to the tibia and femur. Understanding the relative positions of these bone bruises could enhance our comprehension of the knee loading patterns that occur during an ACL injury. (2) Methods: The MEDLINE, EMBASE, and the Cochrane Library databases were searched for studies that evaluated the presence of bone bruises following ACL injuries. Study selection, data extraction, and a systematic review were performed. (3) Results: Bone bruises were observed in 3207 cases (82.8%) at the lateral tibia plateau (LTP), 1608 cases (41.5%) at the medial tibia plateau (MTP), 2765 cases (71.4%) at the lateral femoral condyle (LFC), and 1257 cases (32.4%) at the medial femoral condyle (MFC). Of the 30 studies, 11 were able to assess the anterior to posterior direction. The posterior LTP and center LFC were the most common areas of bone bruises. Among the 30 studies, 14 documented bone bruises across all four sites (LTP, MTP, LFC, and MFC). The most common pattern was bone bruises appearing at the LTP and LFC. (4) Conclusions: The most frequently observed pattern of bone bruises was restricted to the lateral aspects of both the tibia and femur. In cases where bone bruises were present on both the lateral and medial sides, those on the lateral side exhibited greater severity. The positioning of bone bruises along the front-back axis indicated a forward shift of the tibia in relation to the femur during ACL injuries.

The anteromedial retinaculum in ACL-injured knees: An overlooked injury?

The purpose of this study was to retrospectively analyse the pattern of injury to the medial knee structures in anterior cruciate ligament (ACL) injured patients. It was hypothesised that anteromedial injuries would be more common than posteromedial lesions. One hundred and twenty subjects aged 18-25 years with a primary ACL injury were included. Patients were excluded if the time between injury and magnetic resonance imaging (MRI) was more than 28 days or if a knee dislocation or fracture was present. The MRIs were analysed with particular emphasis on injuries to the medial knee structures, menisci and bone bruise patterns. Injuries to the ligaments and anteromedial retinaculum (AMR) were graded according to severity, ranging from periligamentous oedema (grade I), partial fibre disruption of less or more than 50% (grade IIa or IIb) to complete tears (grade III). AMR injury was seen in 87 subjects (72.5%) on the coronal plane and in 88 (73.3%) on the axial plane, with grade III lesions observed in 27 (22.5%) and 29 knees (24.2%). Injuries to the superficial medial collateral ligament (sMCL), deep MCL (dMCL) and posterior oblique ligament (POL) were detected in 60 patients (50%), 93 patients (77.5%)and 38 patients (31.6%). However, grade III injuries to the POL were observed in only seven knees (5.8%). Medial meniscus injuries were associated with lesions of the sMCL and AMR (p < 0.05), while lateral meniscus injuries were significantly more common in patients with dMCL rupture (p < 0.05). Data from this study suggest that injuries to the AMR are much more common than posteromedial lesions in subjects with ACL injuries. Level IV.

Comparison of Bone Bruise Pattern Epidemiology between Anterior Cruciate Ligament Rupture and Patellar Dislocation Patients-Implications of Injury Mechanism.

Different bone bruise patterns observed using magnetic resonance imaging (MRI) after non-contact anterior cruciate ligament (ACL) rupture and lateral patellar dislocation may indicate different knee injury mechanisms. In this study, 77 ACL ruptures and 77 patellar dislocations in knee MR images taken from patients with bone bruises at our institution between August 2020 and March 2022 were selected and analyzed. In order to determine typical bone bruising patterns following by ACL rupture and patellar dislocation, sagittal- and transverse-plane images were used to determine bone bruise locations in the directions of medial-lateral and superior-inferior with MR images. The presence, intensity, and location of the bone bruises in specific areas of the femur and tibial after ACL rupture and patellar dislocation were recorded. Relative bone bruise patterns after ACL rupture and patellar dislocation were classified. The results showed that there were four kinds of bone bruise patterns (1-, 2-, 3-, and 4- bone bruises) after ACL rupture. The most common two patterns after ACL rupture were 3- bone bruises (including the lateral femoral condyle and both the lateral-medial tibial plateau, LF + BT; both the lateral-medial femoral condyle and the lateral tibial plateau, BF + LT; and the medial femoral condyle and both the medial and lateral tibial plateau, MF + BT) followed by 4- bone bruises (both the lateral-medial femoral condyle and the tibial plateau, BF + BT), 2- bone bruises (the lateral femoral condyle and tibial plateau, LF + LT; the medial femoral condyle and the lateral tibial plateau, MF + LT; the lateral femoral condyle and the medial tibial plateau, LF + MT; the medial femoral condyle and the tibial plateau, MF + MT; both the lateral-medial tibial plateau, 0 + BT), and 1- bone bruise (only the lateral tibial plateau, 0 + LT). There was only a 1- bone bruise (the latera femoral condyle and medial patella bone bruise) for patellar dislocation, and the most common pattern of patellar dislocation was in the inferior medial patella and the lateral anterior inferior femur. The results suggested that bone bruise patterns after ACL rupture and patellar dislocation are completely different. There were four kinds of bone bruise patterns after non-contact ACL rupture, while there was only one kind of bone bruise pattern after patellar dislocation in patients, which was in the inferior medial patella and lateral anterior inferior femur.

Poster 306: Examining Preoperative Magnetic Resonance Imaging for Medial Meniscal Ramp Lesions in Patients Surgically Treated for Acute Grade III Combined Posterolateral Corner Knee Injuries

Objectives: While medial meniscocapsular tears ( ramp lesions) are commonly associated with isolated anterior cruciate ligament (ACL) injuries, there are limited descriptions of these meniscal injuries in multi-ligament knee injuries (MLKIs). The purposes of this study were: (1) To retrospectively evaluate preoperative MRIs for the presence of ramp lesions in patients surgically treated for acute grade III combined posterolateral corner knee injuries and (2) To determine if a preoperative posteromedial tibia plateau (PMTP) bone bruise is associated with the presence of preoperative ramp lesions on MRI in these same patients. Methods: Data on consecutive patients at a Level I trauma center with MLKIs between 2001 and 2021 were retrospectively reviewed. Only patients with acute grade III combined PLC injuries who received a magnetic resonance imaging (MRI) scan within 30 days of injury were assessed. Two musculoskeletal radiologists retrospectively reviewed each patient’s preoperative MRI for evidence of ramp lesions and bone bruises (Figure 1). Intra-class correlation coefficients (ICCs) were used to calculate reliability among the reviewers. Multivariate analysis was used to evaluate the relationship between bone bruising patterns and the presence of a ramp lesion on MRI. Results: Sixty-eight patients (79.4% male; mean age, 36.2 ± 13.7 years) with an acute grade III combined PLC injury were included in the study (Table 1). On MRI, the ICC for detection of ramp lesions and PMTP bone bruising were 0.921 and 0.938, respectively. Medial meniscal ramp lesions were diagnosed in 18/68 (26.5%). 11/18 (61.1%) patients with ramp lesions also showed evidence of PMTP bruising, while 13/50 (26.0%) patients without ramp lesions had PMTP bruising (P=0.008) (Table 2). When controlling for age and sex, PTMP bruising was significantly associated with the presence of a ramp lesion in combined PLC injuries (OR, 4.62; P=0.012) (Table 3). Conclusions: Preoperative medial meniscal ramp lesions were diagnosed on MRI in 26.5% of patients with acute grade III combined PLC injuries. In addition, PMTP bone bruising was significantly associated with the presence of a ramp lesion in patients with a grade III combined PLC injury. These findings demonstrate the need to assess for potential ramp lesions at the time of multi-ligament reconstruction. [Table: see text][Table: see text][Table: see text]

Poster 272: The Significance Of Posterior Tibial Slope And Rate Of Concomitant Pathology In Pediatric Tibia Spine Avulsion And Anterior Cruciate Ligament Injuries

Objectives: Fractures of the tibial spine (TSF) occur as a result of an anterior cruciate ligament (ACL) avulsion fracture from the proximal tibia. Both TSF and ACL injuries are associated with concomitant intraarticular pathology seen on Magnetic Resonance Imaging (MRI) and intraoperatively. In addition, posterior tibial slope (PTS) has been identified as a potential risk factor for ACL injury. The purpose of this study is to describe concomitant injuries seen on MRI and at time of surgery for TSF and ACL patients, and to characterize posterior tibial slope in patients who sustain these injuries. Our hypothesis is that ACL and TSF injuries have similar rates of meniscal injury, and that posterior tibial slope is increased in patients with TSF and ACL injuries compared to matched controls. Methods: Utilizing an institutional review board approved retrospective study, we identified patients under 18 years of age who underwent arthroscopic management of a TSF from December 31st 2008 to December 31st 2021. Exclusion criteria were patients with a concomitant lower extremity fracture or posterior cruciate ligament injuries, poor imaging quality, and incomplete medical records. TSF patients were compared to an age and gender matched cohort of patients who underwent surgery for a mid- substance ACL rupture, and a similar control group. We evaluated concomitant injuries based on radiology and operative reports and measured PTS on radiographs as well as medial (MTS) and lateral (LTS) posterior slope on MRI for all groups. We compared tibial slope amongst the groups using a one- way analysis of variance test, and the Fisher’s exact test was used to compare concomitant injuries between the ACL and TSF groups. Results: 85 TSF patients met inclusion criteria, of which 44 had an MRI. There were 41 patients in the ACL group and 44 in the control group. The average age was 11.8 years. Concomitant injuries were identified on MRI in 59.1% of TSF and 51.2% of ACL patients, and intraoperatively in 36.5% of TSF and 37% of ACL patients. The most common concomitant injury was lateral meniscus tears. There was no significant differnce between the TSF and ACL groups in terms of lateral meniscus tears seen on MRI (29.5% TSF vs 31.7 ACL, p=1.0) and seen on arthroscopy (18.2% TSF vs 31.7% ACL, p=0.21). Similarly there were no significant differences between the TSF and ACL group in terms of medial meniscus tears seen on MRI (13.6% vs 17.1%, p = 0.77) and on arthroscopy (9% vs 5%, p=0.19). There was a significant difference between groups when comparing the pivot-shift bone bruise pattern seen on MRI (63.6% TSF vs 90.2% ACL, P= &lt;0.01). There was significantly increased radiographic PTS in the TSF and ACL groups (Radiographs 8.7°+/-3.0° TSF vs 9.5°+/-3.3° ACL vs 6.6°+/-2.3° Control, p= &lt;0.01). This was also seen in the MTS mesured on MRI (MTS 5.3°+/-3.1° TSF vs 4.9°+/-2.7° ACL vs 3.7°+/-2.3° Control p= 0.02). There was no significant difference in LTS between TSF and Controls, but there was between ACL and Controls (LTS 4.1°+/-2.8° TSF vs 6.8°+/- 3.9°ACL vs 4.3°+/- 2.3° Control, p=&lt;0.01). Conclusions: This study is the first to depict tibial slope and bone contusion patterns seen in tibial spine injuries, as well as compare rates of meniscal injury and tibial slope between ACL and control patients. Posterior tibial slope is significantly increased in patients who sustain a TSF or ACL injury, suggesting that it may be a risk factor for injury. Similar rates of concomitant meniscal pathology are seen in both TSF and ACL injured patients, which may reflect similar mechanisms of injury. This also highlights that care must be taken to evaluate for additional pathology when treating TSF and ACL injuries. Future study is needed to determine the role, if any, that tibial slope plays in tibial spine fractures as well as to determine if intraarticular pathology identified on MRI influences longer term patient outcomes.

Examining the Distribution of Bone Bruise Patterns in Contact and Noncontact Acute Anterior Cruciate Ligament Injuries

Background: Bone bruises are commonly seen on magnetic resonance imaging (MRI) in acute anterior cruciate ligament (ACL) injuries and can provide insight into the underlying mechanism of injury. There are limited reports that have compared the bone bruise patterns between contact and noncontact mechanisms of ACL injury. Purpose: To examine and compare the number and location of bone bruises in contact and noncontact ACL injuries. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Three hundred twenty patients who underwent ACL reconstruction surgery between 2015 and 2021 were identified. Inclusion criteria were clear documentation of the mechanism of injury and MRI within 30 days of the injury on a 3-T scanner. Patients with concomitant fractures, injuries to the posterolateral corner or posterior cruciate ligament, and/or previous ipsilateral knee injury were excluded. Patients were stratified into 2 cohorts based on a contact or noncontact mechanism. Preoperative MRI scans were retrospectively reviewed by 2 musculoskeletal radiologists for bone bruises. The number and location of the bone bruises were recorded in the coronal and sagittal planes using fat-suppressed T2-weighted images and a standardized mapping technique. Lateral and medial meniscal tears were recorded from the operative notes, while medial collateral ligament (MCL) injuries were graded on MRI. Results: A total of 220 patients were included, with 142 (64.5%) noncontact injuries and 78 (35.5%) contact injuries. There was a significantly higher frequency of men in the contact cohort compared with the noncontact cohort (69.2% vs 54.2%, P = .030), while age and body mass index were comparable between the 2 cohorts. The bivariate analysis demonstrated a significantly higher rate of combined lateral tibiofemoral (lateral femoral condyle [LFC] + lateral tibial plateau [LTP]) bone bruises (82.1% vs 48.6%, P < .001) and a lower rate of combined medial tibiofemoral (medial femoral condyle [MFC] + medial tibial plateau [MTP]) bone bruises (39.7% vs 66.2%, P < .001) in knees with contact injuries. Similarly, noncontact injuries had a significantly higher rate of centrally located MFC bone bruises (80.3% vs 61.5%, P = .003) and posteriorly located MTP bruises (66.2% vs 52.6%, P = .047). When controlling for age and sex, the multivariate logistical regression model demonstrated that knees with contact injuries were more likely to have LTP bone bruises (OR, 4.721 [95% CI, 1.147-19.433], P = .032) and less likely to have combined medial tibiofemoral (MFC + MTP) bone bruises (OR, 0.331 [95% CI, 0.144-0.762], P = .009) compared with those with noncontact injuries. Conclusion: Significantly different bone bruise patterns were observed on MRI based on ACL injury mechanism, with contact and noncontact injuries demonstrating characteristic findings in the lateral tibiofemoral and medial tibiofemoral compartments, respectively.

Classification of Bone Bruises in Pediatric Patients With Anterior Cruciate Ligament Injuries

Bone bruises are frequently found on magnetic resonance imaging (MRI) after an anterior cruciate ligament (ACL) tear in pediatric patients. To establish a classification system for different bone bruise patterns to estimate the severity of a knee injury in pediatric patients with ACL tears. Cross-sectional study; Level of evidence, 3. A medical database was retrospectively reviewed to identify all cases of primary ACL tears in patients who were aged ≤17 years at the time of the injury and underwent MRI at our institution within 4 weeks of the injury between January 2011 and December 2020. A total of 188 patients were identified (67 male, 121 female; mean age, 15.1 ± 1.4 years). Bone bruises were classified according to their depth and location on MRI in the sagittal and coronal planes. The new classification system identified 3 grades of depth: grade I, the bone bruise was located within the epiphysis but did not reach the epiphyseal plate (n = 54 [35.3%]); grade II, the bone bruise was within the epiphysis that reached the epiphyseal plate (n = 55 [35.9%]); and grade III, the bone bruise was in both the epiphysis and metaphysis (n = 44 [28.8%]). The bone bruise location was classified into 4 types: type a, the deepest bone bruise area was in the lateral tibial plateau (n = 66 [43.1%]); type b, the deepest bone bruise area was in the lateral femoral condyle, commonly occurring in the lateral one-third to two-thirds of the lateral femoral condyle (n = 22 [14.4%]); type c, the bone bruise area had a similar depth in both the lateral femoral condyle and lateral tibial plateau (n = 54 [35.3%]); and type d, the bone bruise area was in the lateral tibial plateau and lateral femoral condyle and extended to the fibular head (n = 11 [7.2%]). The prevalence of collateral ligament injuries increased from grade I to III. All patients with grade III type c bone bruises had meniscal lesions. This new classification system provides a basis for estimating associated lesions of the knee before surgery.

Bone Bruise Patterns Associated With Pediatric and Adult Anterior Cruciate Ligament Tears Are Different

To describe differences in radiographic and magnetic resonance imaging (MRI) findings between adult and pediatric patients with known primary anterior cruciate ligament (ACL) injuries. We performed a retrospective analysis of surgical patients with a history of ACL tears treated at our institution over a 7-year period. Patients were divided into 2 cohorts based on age (≤15 years and ≥21 years). Patients' radiographs and MRI studies were used to compare features including fracture incidence, bone bruise pattern, associated ligamentous injuries, and meniscal injuries between the 2 groups. Proportions of associated findings were analyzed using the 2-proportion z test. Within our cohorts of 52 sex-matched pediatric and adult patients, we found that pediatric patients were more likely to have radiographic evidence of fracture (P= .001) and MRI evidence of lateral femoral condylar bone bruising (P= .012). Adult patients had higher rates of medial femoral condylar bruising (P= .016) and medial proximal tibial bruising (P= .005), as well as popliteal fibular ligament injuries (P= .037), identified on MRI. In this study, we identified differences in bone bruise patterns between pediatric and adult patients with primary ACL tears. Pediatric patients were more likely to have radiographic evidence of fracture and MRI evidence of lateral femoral condylar bone bruising. Adult patients were more likely to show medial femoral condylar and medial proximal tibial bone bruising, as well as popliteal fibular ligament injuries. Level IV, prognostic case series.

Bone Bruise Patterns in Ligamentous Injuries of the Knee With Focus on Anterior Cruciate Ligament.

Introduction After sustaining an anterior cruciate ligament (ACL) injury, the bone bruises seen on magnetic resonance imaging (MRI) could reveal plenty of information regarding the loading mechanisms causing injury to the ACL. The current study was conducted to evaluate the common distribution patterns of bone bruises following an ACL injury and understand the loading mechanisms. Methods The knee MRI sequences of the patients operated arthroscopically for an injured ACL between August 2016 to August 2018 were selected for the study. The distribution pattern of the bone bruises was determined using the sagittal and coronal sections of MRI. The pattern of distribution of the bone bruises was categorized and analyzed by two independent observers. Results Twenty-two patients were found to have bone bruises diagnosed in the MRI scans. The mean age of the patients was 27.8 ± 8.7 years. The pattern of a bone bruises in only the lateral femoral and tibial compartments was the most typical pattern observed in this study. The study pattern has a significant anterior distribution of bone bruises on the outer (lateral) compartment of both the femur and tibia as compared to the inner (medial) compartment (p< .05 and p > .05, respectively). The inter-rater reliability between the two observers by Cronbach's Alpha was 93.2%. Conclusion Having the appropriate information regarding the pattern distribution of bone bruises and the concomitant injuries associated with it furthers our knowledge and helps us understand the loading mechanisms of ACL tears. A combination of coup forces acting on the lateral compartment and the contrecoup varus force on the medial compartment of the knee during the primary pivot-shift injury suggests an an involvement of multiplanar loading patterns at the point of sustaining ACL tear.

Patterns of Associated Knee Ligament and Chondral Injuries in First-Time Traumatic Patellar Dislocation: A Retrospective Magnetic Resonance Imaging (MRI) -Based Study.

Introduction First-time acute traumatic patellar dislocation, when managed without a knee magnetic resonance imaging (MRI) scan, may lead to missed diagnoses of important associated knee injuries. The aim of this study was to ascertain the incidence of associated ligamentous and cartilaginous injuries in first-time traumatic patella dislocation. Methods This was a five-year retrospective study on patients aged 16-45 who had knee MRI scans showing the characteristic bone bruise patterns seen in traumatic lateral patellar dislocation. Anonymized data from the hospital picture archiving and communication system (PACS) was obtained with each scan reviewed by a consultant radiologist, a fellowship-trained orthopaedic knee specialist, and an orthopaedic registrar or resident. Results A total of 200 knee MRI scans were screened. 61 eligible knee MRI scans were included in the study. The patients' ages ranged from 16 to 42 years old, with a mean of 25 years. 73.8% were male. A medial patellofemoral ligament (MPFL) tear or rupture occurred in 58 of 61 knees (95%) with MPFL attenuation in three (5%) injured knees. Meniscal injuries were identified in 5 of 61 knees (8.2%), medial collateral ligament (MCL) injuries in 11 of 61 knees (18%), osteochondral injuries and loose bodies in 17 of 61 knees (27.9%), and anterior cruciate ligament (ACL) injury in one knee (1.6%). Conclusions This single-centre MRI-based study has provided information on the incidence of associated chondral and ligamentous injuries in patients with first-time acute traumatic patellar dislocation. This information will be useful for clinicians when counselling patients and will add to the available literature on this injury. An MRI scan should be obtained in cases of suspected first-time traumatic patellar dislocations, especially in active young patients, due to the incidence of other associated traumatic knee lesions that might need surgical treatment and lead to persisting knee symptoms if neglected.

Posteromedial Tibial Bone Bruise After Anterior Cruciate Ligament Injury: An MRI Study of Bone Bruise Patterns in 208 Patients.

Background:Bone bruise patterns after anterior cruciate ligament (ACL) rupture may predict the presence of intra-articular pathology and help explain the mechanism of injury. Lateral femoral condyle (LFC) and lateral tibial plateau (LTP) bone bruises are pathognomic to ACL rupture. There is a lack of information regarding medial tibial plateau (MTP) and medial femoral condyle (MFC) bone bruises.Purpose:To summarize the prevalence and location of MTP bone bruises with acute ACL rupture and to determine the predictors of MTP bone bruises.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Inclusion criteria were patients who underwent ACL reconstruction between February 2015 and November 2017, magnetic resonance imaging (MRI) within 90 days of injury, and participation in the database. Exclusion criteria included previous ipsilateral surgery, multiligamentous injuries, and incomplete imaging. Due to the large number of cases remaining (n = 600), 150 patients were selected randomly from each year included in the study, for a total of 300 patients. Two readers independently reviewed injury MRI scans using the Costa-Paz bone bruise grading system. Logistic regression was used to identify factors associated with MTP bone bruises.Results:Included were 208 patients (mean age, 23.8 years; mean body mass index, 25.6). The mechanism of injury was noncontact in 59% of injuries, with over half from soccer, basketball, and football. The median time from injury to MRI scan was 12 days. Of the 208 patients, 98% (203/208) had a bone bruise, 79% (164/208) had an MTP bone bruise, and 83% (172/208) had bruises in both medial and lateral compartments. The most common pattern, representing 46.6% of patients (97/208), was a bruise in all 4 locations (MFC, LFC, MTP, and LTP). Of the 164 MTP bruises, 160 (98%) involved the posterior third of the plateau, and 161 were grade 1. The presence of an MFC bruise was the only independent risk factor for an MTP bruise (odds ratio, 3.71). The resulting nomogram demonstrated MFC bruise, sport, and mechanism of injury were the most important predictors of an MTP bruise.Conclusion:MTP bruise after acute ACL rupture was as prevalent as lateral bruises. The presence of a posterior MTP bruise suggested anterior tibial translation at the time of injury and could portend more medial compartment pathology at the time of injury than previously recognized.

Skeletally Immature Patients With Classic Anterior Cruciate Ligament Bone Bruise Patterns Have a Higher Likelihood of Having an Intact Anterior Cruciate Ligament Compared With Skeletally Mature Patients.

The incidence of anterior cruciate ligament (ACL) tears in skeletally immature patients with an ACL bone contusion pattern has been sparsely investigated. The purpose of this study is to investigate whether physeal status has an influence on the likelihood of sustaining an ACL tear when classic bipolar ACL bone bruising pattern is present. Magnetic resonance imaging reports were queried for "contusion" on all patients between 6 and 22 years between 2015 and 2019. Images were reviewed to denote all intra-articular pathology and the physeal status of the femur and tibia. The primary outcome was the incidence of ACL tears in patients with the presence of bipolar bone contusions. Fischer exact testing was used to determine associations. Of 499 patients included, 269 of those had bipolar bone contusions. Patients with bipolar bone contusions and ACL tears had a shorter duration between injury and imaging date compared with patients with ACL tears without bipolar bone contusions (6.9 vs. 38.6d, P =0.05). Patients with an open femoral physis had a higher likelihood of having an intact ACL despite the presence of bipolar bone contusions than patients with a closed femoral physis (10.8% vs. 1.0%, P <0.001). Of patients with bipolar bone contusions, those with an intact ACL were younger than patients with an ACL tear (14.6 vs. 16.4, P =0.017). Although bipolar bone contusions of the central lateral femoral condyle and posterior lateral tibial plateau are typically found after ACL injury, these bipolar contusions can be found concomitantly with an intact ACL and were more often found in relatively younger patients. Patients who have an open femoral physis have a higher likelihood to have an intact ACL despite the presence of bipolar bone contusions compared with patients who have a closed femoral physis. Level IV-cross-sectional.

Proteomic Profile Analysis of Synovial Fluid in Patients With Anterior Cruciate Ligament Tears

Background: Anterior cruciate ligament (ACL) tears are associated with posttraumatic osteoarthritis, but the early biological changes that initiate joint degeneration after this injury are not well characterized. ACL tears typically result in effusion in the knee, which may provide insight into the initial response of the joint to injuries. Hypothesis: Patient- and injury-specific factors are associated with the proteomics of synovial fluid in knees with ACL tears. Study Design: Descriptive laboratory study. Methods: Synovial fluid was collected from 105 patients (38 male, 67 female) with an acute traumatic ACL tear. Patient- and injury-specific factors such as age, sex, body mass index, time from injury, presence/absence of concomitant meniscal tears, and location of concomitant bone bruises (if present) were recorded. The protein concentration of synovial fluid was measured, followed by benchmarking of samples for multi-affinity high-abundance protein depletion. An isotropically labeled high-resolution nano-liquid chromatography with tandem mass spectrometry–based proteomic approach was used to determine the synovial fluid protein profile. Data were processed, quality controlled, and analyzed computationally for each patient and injury factor. Results: The proteomics of synovial fluid from ACL tears was associated with patient sex, injury pattern, and location of bone bruises but not with patient age, body mass index, or time from injury. Knees with an isolated ACL tear had higher glutathione peroxidase 1 (GPX1) and plastin 3 levels than knees with an ACL tear and meniscal tear. A bone bruise on the lateral femoral condyle was associated with elevated leptin and glucose-6-phosphate dehydrogenase (G6PD) levels. A bone bruise on the lateral tibial plateau was associated with decreased GPX1 levels. Male patients had higher matrix metalloproteinase 9 and lower G6PD levels than female patients. Conclusion: Patient sex, injury pattern, and bone bruise location were important determinants of the proteomic profile of effusion resulting from ACL tears. Clinical Relevance: Longitudinal follow-ups to see if and how proteomic differences relate to clinical outcomes and mechanistic studies to assess the role that specific proteins play in the joint are warranted. Ultimately, these investigations could lead to better approaches to predict clinical outcomes and identify possible interventions to optimize outcomes in these patients.

Bruising in Infants: An Approach to the Recognition of Child Physical Abuse.

Infants (children <12 months of age) are maltreated at more than twice the rate of any other child age group, and infants die because of maltreatment at 3 times the rate of any other age group in childhood. The incidence of hospitalization for serious physical abuse in children also is highest for infants. Successful recognition of medically mild signs of physical abuse in infants, such as certain bruising patterns, can, therefore, lead to lifesaving interventions. The importance of the recognition of medically mild injuries due to physical abuse is underscored by the finding that a high percentage of infants (27.5%) hospitalized with serious physical abuse were found to have previously sustained milder injuries, such as bruising. Clinicians must be aware of patterns of bruising suggestive of abuse to distinguish between infants who have been abused and those who have been accidentally injured. To maximize the likelihood that abused infants will be identified and protected, as well to minimize the likelihood that an accidentally injured infant will be mischaracterized as abused, the application of an evidence-based approach to the evaluation of bruised infants should be applied. A consistent, evidence-based practice in this setting also may reduce the influence of racial and socioeconomic bias and decrease disparities in care.

The injury mechanism correlation between MRI and video-analysis in professional football players with an acute ACL knee injury reveals consistent bone bruise patterns

PurposeTo analyze the MRI features, in particular bone bruises pattern, of Anterior Cruciate Ligament (ACL) injured footballers, and to correlate them with the characteristics of injury mechanism and situation obtained from direct video footage.MethodsNineteen professional football (soccer) players that sustained ACL injury while playing during an official match of First League Championship were included in the study. The video of injury was obtained from the Television broadcast. Knee Magnetic Resonance (MRI) was obtained within 7 days from the injury. BB and meniscal lesions were analyzed on MRI, while a video-analysis of mechanisms of ACL injury and injury dynamic were assessed from the videos.ResultsThe most commonly involved Bone Bruise areas in the knee were the Posterior Lateral Tibial Plateau (LTp) in 16 cases (84%) and the Central Lateral Femoral Condyle (LFc) in 11 cases (58%). Three patients (16%) had bone bruise in the Posterior Medial Tibial Plateau (MTp) while none (0%) had bone bruise in the Medial Femoral Condyle. Based on the bone bruise pattern, 11 (58%) had simultaneous LFc and LTp and were defined “Typical” while 8 (42%) had other locations or no bone bruise and were defined “Atypical”. 9 out of 11 injuries (82%) of athletes with “Typical” pattern occurred with a “Pivoting” action”, in contrast to only 1 case (12%) in those with “Atypical” bone bruise pattern (p = 0.0055).The most common situational mechanism pattern on video analysis was “pressing” (n = 7) accounting for the 47% of the “indirect” ACL injuries. In terms of movement pattern, ten injuries (52%) occurred during a “Pivoting” movement (7 pressing, 1 dribbling, 1 tackled, 1 goalkeeping), whereas the remaining were classified as “Planting” in four cases, “Direct Blow” in four cases and “Landing”.ConclusionA well-defined and consistent bone bruise pattern involving the posterior tibial plateau and central femoral condyle of lateral compartment is present in footballers that sustained non-contact and indirect ACL injuries during pivoting with sudden change of direction/deceleration, while heterogeneous patterns were present in those with direct contact or injury mechanisms involving high horizontal velocity.Level of evidenceLevel IV.

Examining the Bone Bruise Patterns in Multiligament Knee Injuries With Peroneal Nerve Injury

Background: Tibiofemoral bone bruise patterns seen on magnetic resonance imaging (MRI) are associated with ligamentous injuries in the acutely injured knee. Bone bruise patterns in multiligament knee injuries (MLKIs) and particularly their association with common peroneal nerve (CPN) injuries are not well described. Purpose: To analyze the tibiofemoral bone bruise patterns in MLKIs with and without peroneal nerve injury. Study Design: Case series; Level of evidence, 4. Methods: We retrospectively identified 123 patients treated for an acute MLKI at a level 1 trauma center between January 2001 and March 2021. Patients were grouped into injury subtypes using the Schenck classification. Within this cohort, patients with clinically documented complete (motor and sensory loss) and/or partial CPN palsies on physical examination were identified. Imaging criteria required an MRI scan on a 1.5 or 3 Tesla scanner within 30 days of the initial MLKI. Images were retrospectively interpreted for bone bruising patterns by 2 board-certified musculoskeletal radiologists. The location of the bone bruises was mapped on fat-suppressed T2-weighted coronal and sagittal images. Bruise patterns were compared among patients with and without CPN injury. Results: Of the 108 patients with a MLKI who met the a priori inclusion criteria, 26 (24.1%) were found to have a CPN injury (N = 20 complete; N = 6 partial) on physical examination. For CPN-injured patients, the most common mechanism of injury was high-energy trauma (N = 19 [73%]). The presence of a grade 3 posterolateral corner (PLC) injury (N = 25; odds ratio [OR], 23.81 [95% CI, 3.08-184.1]; P = .0024), anteromedial femoral condyle bone bruising (N = 24; OR, 21.9 [95% CI, 3.40-202.9]; P < .001), or a documented knee dislocation (N = 16; OR, 3.45 [95% CI, 1.38-8.62]; P = .007) was significantly associated with the presence of a CPN injury. Of the 26 patients with CPN injury, 24 (92.3%) had at least 1 anteromedial femoral condyle bone bruise. All 20 (100%) patients with complete CPN injury also had at least 1 anteromedial femoral condyle bone bruise on MRI. In our MLKI cohort, the presence of anteromedial femoral condyle bone bruising had a sensitivity of 92.3% and a specificity of 64.6% for the presence of CPN injury on physical examination. Conclusion: In our MLKI cohort, the presence of a grade 3 PLC injury had the greatest association with CPN injury. Additionally, anteromedial femoral condyle bone bruising on MRI was a highly sensitive finding that was significantly correlated with CPN injury on physical examination. The high prevalence of grade 3 PLC injuries and anteromedial tibiofemoral bone bruising suggests that these MLKIs with CPN injuries most commonly occurred from a hyperextension-varus mechanism caused by a high-energy blow to the anteromedial knee.

A Novel MRI Mapping Technique for Evaluating Bone Bruising Patterns Associated With Noncontact ACL Ruptures

Background:Bone bruise patterns in the knee can aid in understanding the mechanism of injury in anterior cruciate ligament (ACL) ruptures. There is no universally accepted magnetic resonance imaging (MRI) mapping technique to describe the specific locations of bone bruises.Hypothesis:The authors hypothesized that (1) our novel mapping technique would show high interrater and intrarater reliability for the location of bone bruises in noncontact ACL-injured knees and (2) the bone bruise patterns reported from this technique would support the most common mechanisms of noncontact ACL injury, including valgus stress, anterior tibial translation, and internal tibial rotation.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Included were 43 patients who underwent ACL reconstruction between 2018 and 2020, with MRI within 30 days of the injury on a 3.0-T scanner, documentation of a noncontact mechanism of injury, and no concomitant or previous knee injuries. Images were retrospectively reviewed by 2 radiologists blinded to all clinical data. The locations of bone bruises were mapped on fat-suppressed T2-weighted coronal and sagittal images using a novel technique that combined the International Cartilage Repair Society (ICRS) tibiofemoral articular cartilage surgical lesions diagram and the Whole-Organ Magnetic Resonance Imaging Scoring (WORMS) mapping system. Reliability between the reviewers was assessed using the intraclass correlation coefficient (ICC), where ICC >0.90 indicated excellent agreement.Results:The interrater and intrarater ICCs were 0.918 and 0.974, respectively, for femoral edema mapping and 0.979 and 0.978, respectively, for tibial edema mapping. Significantly more bone bruises were seen within the lateral femoral condyle compared with the medial femoral condyle (67% vs 33%; P < .0001), and more bruises were seen within the lateral tibial plateau compared with the medial tibial plateau (65% vs 35%; P < .0001). Femoral bruises were almost exclusively located in the anterior/central regions (98%) of the condyles as opposed to the posterior region (2%; P < .0001). Tibial bruises were localized to the posterior region (78%) of both plateaus as opposed to the anterior/central regions (22%; P < .0001).Conclusion:The combined mapping technique offered a standardized and reliable method for reporting bone bruises in noncontact ACL injuries. The contusion patterns identified using this technique were indicative of the most commonly reported mechanisms for noncontact ACL injuries.

A STUDY OF DIFFERENT BONE BRUISING PATTERNS ON MAGNETIC RESONANCE IMAGING IN PATIENTS WITH ANTERIOR CRUCIATE LIGAMENT INJURY

Anterior cruciate ligament (ACL) is the primary stabilizing structure of the knee which offers primary resistance to anterior tibial translation and also limits its internal rotation. Sports related injuries are the most common cause of ACL injury and non-contact type mechanism accounts for majority of these cases. Different injury mechanisms that cause ACLinjuries most often also results in osseous injuries of distal femur and proximal tibia and produce different patterns of bone bruise or edema which can be well identied on MRI. The present study aims to nd out the different bone bruise patterns in ACLinjury and also to nd the association between different mechanism of injury and the bone bruise pattern. In this cross sectional, prospective study, 40 patients fullling the inclusion criteria are included over a period of 18 months in a tertiary care hospital. Diagnosis of ACL injury and bone bruise is conrmed on MRI. In our study it was found that the most common bone bruise pattern was over lateral side of both femur and tibia in ACL injury. Among different mechanisms of injury, valgus component at knee and pivoting mechanisms resulted in maximum injuries. There is no statistically signicant association between different mechanism of injury and bone bruise patterns in ACL injury (p-value &gt;0.05). However, in conclusion since a particular mechanism of injury has got more tendency towards a specic bone bruise pattern it is possible that by identifying specic bone bruise pattern on MRI we can have an idea about the mechanism of injury and can also look for other associated injuries along with ACLinjury caused by that particular mechanism.