ACL Injuries and Meniscal Lesion: Hand in Hand?

Objective: To assess the incidence, nature and pattern of meniscal tear in ACL injury. Methodology: A retrospective study was conducted among the patients who were admitted and treated for ACL tear in Saveetha Medical And College And Hospital over a 2-year period from August 2019-August 2021. There were 52 patients admitted and treated for the same. The case records of each of the patients were reviewed to find the incidence of meniscal lesion in ACL tear and were then analyzed using appropriate statistical tests. Results: 52 patients with ACL tear were reviewed in this study. ACL tear was most commonly reported in younger age group of 20-29 (46.15%). Out of which, 19(36.54%) patients had meniscal tears. About 9(47.37%) patients had lateral meniscus tear, 6(31.58%) had medial meniscus tear and 4(21.05%) had bilateral meniscal tear. It was seen that bucket handle injury (n=12) was the most common meniscus tear overall. Radial tear was most specifically common in bilateral meniscus injury (N=4). Conclusion: Meniscal tears are the most common intra articular lesions associated with ACL tear. It was most commonly reported in the age group of 20-29. We found that the incidence of lateral meniscal tear was significantly higher in the patients rather than medial meniscal tear. Bucket handle injury was the most commonly reported tear in meniscal injury. Therefore, the surgeon needs to equip himself with the necessary meniscal repair instruments in his armamentarium

Improved Deep Convolutional Neural Network to Classify Osteoarthritis from Anterior Cruciate Ligament Tear Using Magnetic Resonance Imaging

Anterior cruciate ligament (ACL) tear is caused by partially or completely torn ACL ligament in the knee, especially in sportsmen. There is a need to classify the ACL tear before it fully ruptures to avoid osteoarthritis. This research aims to identify ACL tears automatically and efficiently with a deep learning approach. A dataset was gathered, consisting of 917 knee magnetic resonance images (MRI) from Clinical Hospital Centre Rijeka, Croatia. The dataset we used consists of three classes: non-injured, partial tears, and fully ruptured knee MRI. The study compares and evaluates two variants of convolutional neural networks (CNN). We first tested the standard CNN model of five layers and then a customized CNN model of eleven layers. Eight different hyper-parameters were adjusted and tested on both variants. Our customized CNN model showed good results after a 25% random split using RMSprop and a learning rate of 0.001. The average evaluations are measured by accuracy, precision, sensitivity, specificity, and F1-score in the case of the standard CNN using the Adam optimizer with a learning rate of 0.001, i.e., 96.3%, 95%, 96%, 96.9%, and 95.6%, respectively. In the case of the customized CNN model, using the same evaluation measures, the model performed at 98.6%, 98%, 98%, 98.5%, and 98%, respectively, using an RMSprop optimizer with a learning rate of 0.001. Moreover, we also present our results on the receiver operating curve and area under the curve (ROC AUC). The customized CNN model with the Adam optimizer and a learning rate of 0.001 achieved 0.99 over three classes was highest among all. The model showed good results overall, and in the future, we can improve it to apply other CNN architectures to detect and segment other ligament parts like meniscus and cartilages.

Lesões do Joelho associadas à Rotura do Ligamento Cruzado Anterior em População Pediátrica

Our goal was to assess the type and frequency of injuries associated with torn anterior cruciate ligament (ACL) in the pediatric population, as well as to compare patterns of associated injuries between children/adolescents and adults. We included all children and adolescents undergoing ACL reconstruction at our institution between 2013-2019. We analyzed the type and frequency of knee injuries associated (meniscus, cartilage and collateral ligaments) with ACL tears. We included 84 adolescents, with a mean age of 15.9 years. In total, 69% had associated injuries, with meniscal injuries being the most frequent (66.7%). The lateral meniscus was more frequently involved than the medial (48.8% vs 35.7%). Chondral lesions were only detected in 6% of children/adolescents. In adults, unlike what was seen in adolescents, the association of ACL tear with medial meniscus injury is more frequent than in the lateral meniscus. It is concluded that the main knee injury associated with ACL tear in children and adolescents is indisputably the meniscal injury and that only a small part (31%) has isolated ACL injury.

Femur-tibia Angle and Patella-tibia Angle: New Indicators for Diagnosing Anterior Cruciate Ligament Tears in Magnetic Resonance Imaging

Background: Torn anterior cruciate ligament (ACL) contributes to internal rotation of tibia. However, there is no indicator in MRI to reflect the rotation of knee joint. So the purpose of this study is to introduce two new measurements in MRI, femur-tibia angle (FTA) and patella-tibia angle (PTA), which reflect the rotation of knee joint and assess their role in diagnosing ACL tears.Methods: Present study retrospectively reviewed the cases of primary arthroscopic knee surgery from January 2018 to December 2019 from the Arthroscopy Database at Guangdong Provincial People's Hospital. Firstly, comparisons of different measurements were conducted between the ACL tears group and isolated meniscus injury group. Then, the measurements were tested in diagnosing complete or partial ACL tears. Diagnostic performance of different measurements was assessed by area under the curve (AUC) of receiver operating characteristic (ROC) curve and cutoff values were determined by Youden index. Results: FTA and PTA in ACL tears group had 4.79 and 7.36 degrees more than that of control group (p = 0.022 and < 0.001, respectively). Besides, ACL angle and distance of anterior tibial subluxation (D) also showed significant differences (p<0.05). In distinguishing complete ACL tear with intact ACL, the ROC curves indicated that ACL angle had the highest AUC of 0.906 (95% CI: 0.833-0.978) while AUC of PTA was 0.849 (95% CI: 0.763-0.936) and AUC of FTA was 0.809 (95% CI: 0.710-0.908). In distinguishing partial ACL tear with intact ACL, the ROC curves showed that FTA and PTA had the highest AUCs of 0.847 and 0.813 with 95% CI of 0.737-0.957 and 0.680-0.947, respectively. In contrast, the AUCs of ACL angle and D were only 0.519 and 0.387 with 95% CI of 0.292-0.745 and 0.227-0.546.Conclusion: Present study introduced two new quantitative parameters, FTA and PTA, to assess the rotation of knee joint. FTA and PTA increased when ACL tears and they might be valuable in diagnosing ACL tears, especially in distinguishing partial ACL tear with intact ACL which was poorly diagnosed in MRI.

ANTERIOR CRUCIATE LIGAMENT TEAR FOLLOWING SURGICAL TREATMENT OF PEDIATRIC TIBIAL EMINENCE FRACTURE IN A MULTICENTER COHORT

Background: While operative treatment of displaced pediatric tibial eminence fractures has generally been shown to be safe, post-operative complications including arthrofibrosis, infection, fixation failure, and postoperative ipsilateral ACL injuries remain prevalent. The purpose of this study was to describe the prevalence of and risk factors for post-operative ACL tears in a cohort of patients surgically treated for tibial eminence fracture. Methods: We performed a retrospective review of children undergoing treatment of a tibial eminence fracture at 10 tertiary children’s hospitals.. The primary outcome was subsequent ACL rupture. Patients with 2 year follow up data and those that had met the primary outcome within the 2 year period, were analyzed for demographics, risk factors and survival analyses Results: 385 pediatric patients were reviewed. Overall, 46 patients had either 2 year follow up data or met the primary outcome measure of an ACL tear prior to the 2 year mark. Mean age was 11.2 years old (SD 2.8), and the median follow time was 36.4 months (SD 17.7 months) There was a 21.7% incidence of subsequent ACL tear in the cohort analyzed. Subsequent ACL tears occurred at a median of 10.2 months (SD 19.5 months) postoperatively. There was a statistically significant association with higher Myers & McKeever grade tibial spine fractures (Type III and IV) and subsequent ACL rupture ( p=0.006). Subsequent ACL tears occurred in patients who were older when they had their original tibial eminence fracture, 13.4 years old versus 11.3 years old ( p=0.035). There was no statistically significant relationship between ipsilateral ACL tear and body mass index, operative time, fixation method used, postoperative weight bearing status, type of postoperative immobilization, contact versus non-contact injury mechanism, type of post-operative physical therapy protocol based on chi-squared or t-test ( p>0.05). Conclusion: Subsequent ipsilateral ACL tears following operatively treated pediatric tibial eminence fractures in a large multicenter cohort occurred at a rate of 21.7%. They were associated with completely displaced (Type III or IV) tibial eminence fractures, and older patients. Clinicians should therefore continue to follow patients for at least 2 years after treatment of pediatric tibial eminence fractures in order to track this potential complication. [Table: see text]

MAGNETIC RESONANCE IMAGING OF LATERAL MENISCAL POSTERIOR ROOT TEARS IN THE ADOLESCENT KNEE: IS THE DIAGNOSIS MISSED, MENTIONED, OR MADE?

Background: The meniscal roots play a vital role in maintaining proper knee kinematics. Neglected meniscal root tears place excess stress on the articular cartilage and increase the risk of premature osteoarthritis. As opposed to medial meniscal root tears, lateral meniscal posterior root tears (LMPRTs) are more likely to be associated with anterior cruciate ligament (ACL) pathology. Failure to identify and address meniscal root tears may place undue loads on ACL grafts and lead to inferior post-surgical outcomes. Purpose: To examine preoperative knee magnetic resonance imaging (MRI) radiologist interpretations for the identification of lateral meniscal root pathology in children and adolescents. Methods: We performed a retrospective review of children and adolescents that underwnent knee arthroscopy between 3/1/2010 and 4/1/2020 and had an arthroscopically confirmed LMPRT. Arthroscopic findings were compared to the reading radiologist’s preoperative MRI interpretations. LMPRTs were graded using the LaPrade classification. ANOVA was performed to assess if body mass index (BMI), open physes, time from injury to MRI, time from MRI to surgery, MRI magnet field strength, musculoskeletal radiologist designation, insurance type and tear grade were associated with the preoperative MRI identification of a LMPRT. Results: During the study period, 1285 knee arthroscopies were performed. 607 of which were ACL reconstructions. 54 children were found to have a LMPRT arthroscopically and all were associated with an ACL tear 54/607 (9%). One patient had 2 preoperative MRIs for a total of 55 MRIs in 54 pateints. Average age was 16 years (range 14-21). Preoperative MRI diagnosis of a LMPRT was made in only 14/55 (25%) and missed in 22/55 (40%). In 19/55 (35%), pathology of the lateral meniscus nonspecific to the root was mentioned. Lateral joint line tenderness was present in 23/54 (46%). There was no statistical significance found in regards to patient BMI, skeletal maturity, time from injury to MRI, time from MRI to surgery, MRI magnet strength, if the radiologist was musculoskeletal fellowship-trained, or insurance type, with a reliable diagnosis. (Table) Conclusion: The final interpretation of preoperative MRIs did not provide a clear definitive diagnosis of a LMPRT in 75 % in patients. As the intraoperative management of LMPRTs can be involved and diverge from standard meniscal work, preoperative diagnosis would be advantageous. All LMPRTs in this study were associated with a concomitant ACL tear. Surgeons caring for ACL tears in children and adolescents should be prepared to treat a LMPRT regardless of a inconclusive MRI interpretation for meniscal root pathology. [Table: see text]

LCL IN A SINGLE CORONAL SLICE – A NOVEL SIGN FOR IDENTIFYING ACL DEFICIENT PATIENTS AND PREDICTING RISK OF FUTURE GRAFT FAILURE

Background: The ACL deficient knee is predisposed to anterior translation and internal rotation of the tibia. Hypothesis/Purpose: To show that knee deformity in an ACL deficient knee will produce a more vertical orientation of the lateral collateral ligament (LCL), allowing for the entire length of the LCL to be visualized on a single coronal slice (coronal LCL sign) on MRI, and that this sign is indicative of a greater risk for graft failure after ACL reconstruction. Methods: Charts were retrospectively reviewed to create 3 separate cohorts: normal ACL and no pathology involving the collateral ligaments (control cohort), ACL reconstruction without evidence for graft rupture, and ACL reconstruction with graft failure. Tibial translation and femorotibial rotation were measured on MRI, and posterior tibial slope was measured on lateral knee radiographs. Imaging was reviewed for the presence of the coronal LCL sign. Results: Deficient ACL (n=153) compared with intact ACL (n=70) was associated with significantly greater displacement regarding anterior translation (5.8mm internal rotation vs 0.3mm external rotation, p<0.001, respectively) and internal rotation (5.2 degrees vs. -2.4 degrees, p<0.001, respectively). The coronal LCL sign was present in a greater percentage of ACL deficient patients than intact ACL controls (68.6% vs. 18.6%, p<0.001, respectively) and associated with greater anterior tibial translation (7.2mm vs. 0.2mm vs., p<0.001) and internal tibial rotation (7.5 degrees vs 2.4 degrees, p=0.074). Multivariate analysis revealed the coronal LCL sign was significantly associated with an ACL tear (OR 12.8, p<0.001). Of the 153 ACL deficient cohort, 114 had no graft failure patients and 39 experienced graft failure. Mean follow-up time was 3.5 years (2 – 9.4 years). Coronal LCL sign was associated with graft failure (p=0.013), with an odds ratio of 4.3 for graft failure (p=0.003). Comparison of pre- and post-ACL reconstruction MRI in the graft failure cohort demonstrated reduced internal rotation, p= 0.00, but no change in coronal LCL sign (p=0.922). Conclusion: Our study shows that the coronal LCL sign correlates with the presence of an ACL tear and functions as a surrogate for the extent of axial and sagittal deformity. Further, we show that tibia internal rotation and posterior slope are independent predictors of ACL graft failure in adolescents. Whereas, the value of internal rotation could be improved with ACL reconstruction, the presence of the coronal LCL sign persisted over time and was predictive of graft rupture (without the need to make measurements or memorize values of significant risk). [Table: see text][Figure: see text]