Association between time from anterior cruciate ligament injury to reconstruction and morphological changes of the intercondylar notch using MRI and arthroscopy

High-resolution oblique coronal MRI at optimal flexed-knee angle: a novel imaging method for enhanced anterior cruciate ligament tear diagnosis

BACKGROUND

The accuracy of traditional knee MR imaging in diagnosing anterior cruciate ligament tears, especially partial tears, is relatively low, which may lead to misdiagnosis and missed diagnosis. This study aimed to assess the diagnostic performance of a novel imaging method, high-resolution oblique coronal MRI at an optimal flexed-knee Angle, for ACL tears.

METHODS

50 healthy volunteers were scanned with a scan-assisted device for the optimal flexion angle of ACL. For 92 knee trauma patients selected strictly according to inclusion and exclusion criteria, conventional extended-knee scans (control group) and high-resolution oblique coronal scans based on the optimal flexed-knee angle (experimental group) were conducted. Two observers rated ACL visibility blindly on a 5-point scale. Arthroscopy-defined outcomes determined diagnostic metrics for each method and sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated.

RESULTS

The average optimal flexion angle for healthy volunteers was approximately 30° (30.3° ± 5.0°). Imaging demonstrated complete visualization of the ACL in 96.7% of images in the experimental group versus 12.0% in the control group. The diagnostic indicators of the experimental group surpassed those of the control group: sensitivity (94.9% vs. 76.3%), specificity (97.0% vs. 81.8%), positive predictive value (98.2% vs. 88.2%), negative predictive value(91.4% vs. 65.9%), and accuracy (95.7% vs. 78.3%). ROC analysis indicated superior diagnostic performance in the experimental group, with an AUC of 0.945 compared with 0.776 for the control group (p < 0.0001).

CONCLUSIONS

High-resolution oblique coronal imaging at the optimal 30° flexed-knee angle improved ACL visualization and diagnostic performance compared with conventional techniques.

Predictors of lower knee function improvement two years after anterior cruciate ligament reconstruction

OBJECTIVES

The extent to which knee functions improve after anterior cruciate ligament reconstruction (ACLR) varies. This study aimed to determine the factors that affect lower knee function improvement after two years of ACLR.

METHODS

The study included 159 patients who underwent ACLR in the Indonesian ACL community between August 2018 and April 2020. The concomitant injury and graft types of ACLR were determined using patients' pre-surgical MRI and medical records. The five subscales of the knee injury and osteoarthritis outcome score (KOOS) were used to evaluate the patient at baseline, first year, and second year following ACLR. A linear mixed-effect model (LMEM) was used to predict the longitudinal improvement models for the five-subscales KOOS score after ACLR.

RESULTS

The LMEM predicted lower KOOS subscales scores improvements by 0.5 for QOL, 0.1 for symptom, ADL, and QOL, and 0.2 for sports/recreation, respectively, for a one score increase of age and time from injury to surgery. Male patients had higher KOOS subscale scores with the improvement of pain, symptom, and ADL by 5.7, 5.9, and 6.3 compared to female patients, respectively, while patients with patellar tendon grafts had lower improvement of KOOS score pain by 6.5 compared to hamstring tendon grafts.

CONCLUSION

As the age and time from injury to surgery increased, the KOOS subscales scores of QOL and symptoms, ADL, sports/recreation, and QOL decreased. Male patients reported higher KOOS subscales scores for pain, symptoms, and ADL, while patients with patella tendon grafts had a lower improvement in pain score.

The Risk Factors and Preventive Strategies of Poor Knee Functions and Osteoarthritis after Anterior Cruciate Ligament Reconstruction: A Narrative Review

Anterior cruciate ligament reconstruction (ACLR) is the standard surgical treatment for ACL injury, which typically uses a graft to replace the torn ligament in the knee that uses small incisions with minimally invasive surgery. The optimal knee functions following ACLR depend on rehabilitation processes before and after the surgery. Knee function is the ability of the knee to perform various types of functional movements like walking, squatting, running, jumping, and pivoting where patients expect to achieve maximum knee function or at least more than 80% of its initial condition before the injury to avoid being categorized as poor knee function after ACLR. Patients use patient-reported outcome measures to collect data on their health status and quality of life after ACLR. Post-traumatic osteoarthritis (PTOA) is a type of OA that manifests in local cartilage injury caused by chondrocyte death, and matrix dispersion occurs following a joint injury like ACL injury. Gender, time from injury to surgery, and graft type were considered as risk factors for poor knee function after ACLR, while overweight, meniscus tear, and cartilage defect as risk factors for PTOA. However, age is an internal risk factor for both poor knee function and PTOA following ACLR. This review suggests several strategies to prevent both conditions, including a pre-operative program, comprehensive rehabilitation, body weight control, and return to sport (RTS) consideration based on physical capacity, proper time, and psychological readiness.

Medial meniscus tears are most prevalent in type I ACL tears, while type I ACL tears only account for 8% of all ACL tears

PURPOSE

This study aimed to assess the distribution of different anterior cruciate ligament (ACL) tear locations in different magnetic resonance imaging (MRI) planes, and to explore the relationships of ACL tear types with both meniscus injuries and bone bruising.

METHODS

A retrospective study was performed in patients under 60 years old who underwent MRI scans in the sagittal and coronal oblique planes of the knee for ACL tears between 2014 and 2020. Patients with reports of chronic tears, partial tears, or prior surgeries were excluded. Tear locations were classified into five types, and the meniscus tear measurement variables included the presence of ramp, root, bucket-handle, and other types of tears. All injuries were confirmed by arthroscopy. Meanwhile, the presence and location of bone bruising were analysed and scored with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) bone bruising subscale.

RESULTS

A total of 291 patients were included. The prevalence rates of type I and type III injuries were 23/291 (7.9%) and 145/291 (49.8%) in the sagittal plane and 22/291 (7.6%) and 179/291 (61.5%) in the oblique coronal plane, respectively. The prevalence of medial meniscus tears with ACL tears was 126/291 (43.3%), while that of lateral meniscus tears with ACL tears was 77/291 (26.5%). The highest prevalence of medial meniscus injury with ACL tears was 15/22 (68.2%) for type I injuries. Bone bruises were located on the lateral femoral center in 125 patients (46%) and on the lateral tibia posterior in 132 patients (48%); the common areas of bone bruising were slightly correlated with type III ACL tears but not correlated with type I ACL tears.

CONCLUSION

The plane in which an MRI scan is performed affects the classification of ACL tears. The tear type is associated with the prevalence of medial meniscus injuries, and medial meniscus tears are most prevalent in type I ACL tears.

LEVEL OF EVIDENCE

IV.

The intercondylar fossa-A narrative review

The intercondylar fossa (“intercondylar notch,” IN) is a groove at the distal end of the femur, housing important stabilizing structures: cruciate ligaments and meniscofemoral ligaments. As the risk for injury to these structures correlates with changes to the IN, exact knowledge of its morphology, possible physiological and pathological changes and different approaches for evaluating it are important. The divergent ways of assessing the IN and the corresponding measurement methods have led to various descriptions of its possible shapes. Ridges at the medial and lateral wall are considered clinically important because they can help with orientation during arthroscopy, whereas ridges at the osteochondral border could affect the risk of ligament injury. Changes related to aging and sex differences have been documented, further emphasizing the importance of individual assessment of the knee joint. Overall, it is of the utmost importance to remember the interactions between the osseous housing and the structures within.