Diagnostic accuracy of dynamic ultrasound imaging in partial and complete anterior cruciate ligament tears: a retrospective study in 247 patients

Return to Play in the Professional Athlete

The management of any injury in elite athletes poses unique challenges distinct from the general population because the goal is rapid recovery and return to play (RTP) while simultaneously managing residual symptoms and minimizing risk of reinjury. The time required for treatment, recovery, and return to peak performance can have consequences for both the athlete and his or her team: financial implications, psychological stressors, team dynamics, and future performance. RTP after an injury in the professional athlete requires a complex decision-making process with many stakeholders. Several factors influence this decision, not the least of which is the type and mechanism of injury. This article provides an overview of the RTP process including nonmedical factors that may influence this decision, common injuries seen in professional athletes, injury patterns particular to certain popular sports, and imaging guidelines for such injuries.

The use of ultrasonography as an effective screening tool for chronic posterior cruciate ligament injuries

PURPOSE

We aimed to explore the applicability and validity of ultrasonography for diagnosing chronic posterior cruciate ligament (PCL) injuries.

METHODS

PCL thickness was measured at 2 cm proximal to the tibia insertion site. Using the same ultrasonography image, the angle tangent to the PCL from the tibia insertion site was also measured. These data were analyzed by plotting the receiver operating curve (ROC), and the sensitivity and specificity were calculated according to the optimal cut-off point. Ultrasonography data from the PCLinjured knee were compared with those from the contralateral uninjured knee of the same patient.

RESULTS

Twelve men and six women, with a mean age of 28.8 ± 14.0 years, were included in this study. The mean time from injury to medical examination was 10.0 ± 6.7 months. The mean thickness of the PCL was 8.1 ± 1.9 mm on the affected side and 5.8 ± 1.2 mm on the uninjured side, with the affected side being significantly thicker. ROC analysis revealed that the optimal cut-off value for the thickness of chronic PCL injuries was 6.5 mm (sensitivity 83.3%, specificity 77.8%, area under the curve [AUC] = 0.87). The optimal cut-off value for the angle was 20° (sensitivity 88.9%, specificity 94.4%, AUC = 0.96).

CONCLUSION

Ultrasonography is useful as a screening tool for chronic PCL injuries. The optimal cut-off point was 6.5 mm for thickness and 20° for angle.

LEVEL OF EVIDENCE

IV.

Evaluation of the knee joint with ultrasound and magnetic resonance imaging

The knee joint relies on a combination of deep and superficial structures for stability and function. Both ultrasound and high-resolution magnetic resonance imaging are extremely useful in evaluating these structures and associated pathology. This article reviews a combination of critical anatomic structures, joint abnormalities, and pathologic conditions at the knee joint, while highlighting the merits, limitations, and pitfalls of the two imaging modalities. A clear appreciation of each method paired with its relative strengths will aid in expediting diagnosis and appropriate treatment for a wide range of knee joint conditions.

Prone Lachman with Ultrasound: A Literature Review and Description of the Technique

ABSTRACT

Magnetic resonance imaging is the current gold standard imaging modality for diagnosing anterior cruciate ligament (ACL) tears. However, ultrasound has grown in popularity for detecting ACL injuries because of its low cost, portability, and dynamic assessment capabilities. Recent studies demonstrate high sensitivity and specificity for diagnosing isolated ACL tears via ultrasound, but tremendous heterogeneity remains for optimal technique including patient positioning, transducer placement, and dynamic versus static ultrasound usage. As ultrasound becomes ubiquitous in clinics, training rooms, and on the sidelines, identifying objective and sensitive measurements to appropriately screen athletes for significant knee injuries is imperative. This article aims to review the current role of diagnostic ultrasound in ACL injuries and propose a standardized version of the Prone Lachman with Ultrasound test, which is an objective, reliable, and easily reproducible technique to evaluate ACL competency. Developing a standardized protocol will expand the use of point-of-care ultrasound, which may reduce cost and improve efficiency in care.

Superb microvascular imaging (SMI) detects increased vascularity of the torn anterior cruciate ligament

PURPOSE

Ultrasound with superb microvascular imaging (SMI) is a novel microvascular imaging technology which may be useful to assess the vascularity of the torn anterior cruciate ligament (ACL) as a potential measure of healing potential following surgery. This study aimed to quantify the vascularity of the torn and intact ACL using ultrasound with SMI.

METHODS

23 patients (mean age ± standard deviation, 27.1 ± 12.8 years), who were diagnosed with an ACL tear with an intact contralateral ACL were enrolled (ACL injury group). Ten healthy volunteers (36.1 ± 4.9 years) who had intact ACLs in both knees were also recruited (ACL healthy controls). The vascularity of the ACL was assessed using SMI within 15 mm from the tibial insertion in both knees. The amount of the vascular signal was assessed using a semi-quantitative grading scale (vascularity grade: grade 0-3) and a quantified ratio of vascularized area with respect to total area of the region of interest (vascularity ratio).

RESULTS

In the ACL injury group, a significantly higher vascularity grade and ratio were observed in the torn ACL (vascularity grade 0-3: 1, 8, 7, and 7 patients, respectively; vascularity ratio: 1.3 ± 1.4%) than the contralateral intact ACL (vascularity grade 0-3: 21, 1, 1, and 0 patients, respectively; vascularity ratio: 0.1 ± 0.5%) (P < 0.001), whereas no significant difference was observed between both ACLs in the ACL healthy control group.

CONCLUSIONS

SMI was useful to assess the increased vascularity in torn ACL, which may reflect the potential for, or state of, ACL maturation following reconstruction or repair.

LEVEL OF EVIDENCE

Level III.

Dynamic ultrasonography in the diagnosis of acute anterior cruciate ligament injury - a case report

In the reported case of acute grade 3 anterior cruciate ligament injury, clinical examination and magnetic resonance imaging findings were in conflict, leading to confusion. Ultimately, dynamic ultrasound imaging proved to be the decisive test. The article describes the steps taken to reach the diagnosis. In addition, possible future diagnostic improvements are discussed. Dynamic ultrasound imaging, performed as part of the physical examination, is a valuable supplement to medical documentation. It provides appreciable diagnostic performance for the detection of anterior cruciate ligament insufficiency. Physical examination combined with magnetic resonance imaging, even though they represent the current diagnostic standard, have their limitations.

A Reliable, Ultrasound-Based Method for the Diagnosis of Discoid Lateral Meniscus

PURPOSE

To explore the feasibility and validity of ultrasound in the diagnosis of discoid lateral meniscus (DLM) by comparing quantitatively the morphologic difference between DLM and normal lateral meniscus.

METHODS

This study was designed to develop and validate the ultrasound diagnostic criterion for DLM. In the development stage (July 2018 to June 2019), data from 180 subjects were used to derive the ultrasound diagnostic criterion, including 90 patients diagnosed as DLM by magnetic resonance imaging (DLM group) and 90 matched controls diagnosed as normal lateral meniscus diagnosed by magnetic resonance imaging (control group). Twelve distinct parameters of meniscus thickness, width, 0.5∗thickness/width, and angle were obtained through anterior, lateral, and posterior views with the probe oriented perpendicular to the lateral tibiofemoral joint line. In the validation stage (July 2019 to December 2019), data from 324 additional participants were used to validate the criterion derived from the development stage. Differences of the continuous variables and categorical variables between the 2 groups were analyzed by an independent t test and χ² test, respectively. The diagnostic value of parameters was analyzed by the receiver operating characteristic curve.

RESULTS

In the development stage, significant differences were found in the above 12 parameters between the 2 groups (P < .05 for all). Cut-off values of anterior meniscus angle, meniscus body angle, and posterior meniscus angle were 28.45°, 27.85°, and 29.15°, respectively. The area under the curve, sensitivity, and specificity of anterior meniscus angle (0.953, 95.6%, 91.1%), meniscus body angle (0.980, 95.6%, 95.6%), and posterior meniscus angle (0.942, 80.0%, 97.8%) were greater than other parameters. In the validation stage, the sensitivity, specificity, and accuracy of anterior meniscus angle, meniscus body angle, and posterior meniscus angle in diagnosing DLM were as high as 91.3%, 88.6%, and 89.2%; 94.2%, 93.3%, and 93.5%; and 76.8%, 95.7%, and 91.7%.

CONCLUSIONS

DLM can be reliably diagnosed by ultrasound measurements of anterior meniscus angle, meniscal body angle, and posterior meniscus angle.

LEVEL OF EVIDENCE

Level III, case-control study.