Ultrasound Imaging of the Anterior Cruciate Ligament: A Pictorial Essay and Narrative Review

Ultrasound imaging of the posterior lateral corner of the knee: a pictorial review of anatomy and pathologies

Assessment of the posterior lateral knee pain poses diagnostic challenges, requiring accurate evaluation of various structures in light of the medical history and physical examination. Despite substantial progress in the ultrasonographic diagnosis of musculoskeletal disorders, the current protocol (EURO-MUSCULUS/USPRM. Basic scanning protocols for knee) fails to conduct a comprehensive investigation into the intricate, tendons, and ligaments of the posterior lateral knee. This pictorial review aims to bridge this gap by offering a systematic approach to utilize ultrasound examination of the less-discussed structures in this specific region. Providing cadaveric and magnetic resonance images, this essay demonstrates the efficacy of ultrasound in diagnosing posterior lateral knee pain. Notably, pathologies such as ligamentous sprains and tears are clearly discernible. Moreover, the integration of ultrasound guidance plays a vital role in reducing the risk of inadvertent neurovascular injury during injection, such as the common peroneal nerve and lateral genicular artery. This comprehensive approach will enhance clinicians' understanding and equip them with effective management strategies for posterior lateral knee pain.Critical relevance statement In this visual exposition, we delve into the intricacies of the posterior lateral corner of the knee. Offering a methodical approach to employ ultrasound for visualization of the less-explored structures within this region, the authors aim to enhance the diagnosis in posterior lateral knee pain.Key points1. Ultrasound excels at revealing intricate structures in the posterior lateral knee.2. Due to proximity of vital structures, extreme caution is crucial during injections.3. Employing dynamic scan and understanding ligaments enables a comprehensive exploration of pathologies.

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.

Ultrasound guided arthroscopic meniscus surgery

Ultrasound is a useful adjunctive intra-operative imaging modality for soft tissue pathologies. It is readily available in the operating theater and has the distinct advantage of being more portable than an MRI, with no harmful radiation. It is especially useful for determining if any extra articular cysts have been decompressed through arthroscopic surgery, if a parameniscal cyst has been removed completely or if extrusion has been reduced adequately in a meniscus root repair. In our series, intra-operative ultrasound was used for two cases of medial meniscus horizontal tear with meniscus cyst excision, one case of lateral parameniscal cyst without a communicating tear, and five cases of meniscus root repairs. Ultrasound has the potential to be an important intra-operative diagnostic modality not only in diagnosing pathologies but also accurately localizing the soft tissue pathology, which is critical in arthroscopic surgery where the incisions are small. It also has the added advantage of guiding portal placements, especially in areas where there are neurovascular structures, to avoid injuring them. However, training in its effective use by the surgeon is important.

EURO-MUSCULUS/USPRM Dynamic Ultrasound Protocols for Knee

ABSTRACT

In this dynamic scanning protocol, ultrasound examination of the knee is described using various maneuvers to assess different conditions. Real-time patient examination and scanning videos are used for better simulation of the daily clinical practice. The protocol is prepared by several/international experts in the field of musculoskeletal ultrasound and within the umbrella of European Musculoskeletal Ultrasound Study Group in Physical and Rehabilitation Medicine/Ultrasound Study Group of the International Society of Physical and Rehabilitation Medicine.

Ultrasound Imaging in Predicting the Autograft Size in Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-Analysis

Anterior cruciate ligament (ACL) reconstruction is widely used to restore knee stability after injury, but the risk of revision surgery increases when the autograft size is inadequate. Ultrasound (US) measurements of preoperative target tendons have been applied to predict the intraoperative autograft size, with various outcomes across different studies. This systematic review and meta-analysis aimed to summarize the evidence and investigate the usefulness of US in predicting autograft size. Electronic databases were searched for relevant studies from inception to 19 January 2022. The primary outcome was the correlation between the preoperative US measurements of donor tendons and intraoperative autograft size. The secondary outcomes encompassed the predictive performance of US for autograft size and the comparison between US and magnetic resonance imaging (MRI) for preoperative tendon measurements. Nine studies, comprising 249 patients, were enrolled. The preoperative US measurements of the donor tendons demonstrated a significant positive correlation with their intraoperative autograft diameter, with a pooled correlation coefficient of 0.443 (95% confidence interval [CI], 0.266−0.591, p < 0.001) for the gracilis and semitendinosus autograft, 0.525 (95% CI, 0.114−0.783, p = 0.015) for the semitendinosus autograft, and 0.475 (95% CI, 0.187−0.687, p = 0.002) for the gracilis autograft. The pooled sensitivity and specificity of US imaging in predicting the autograft diameter were 0.83 (95% CI 0.57−0.95) and 0.70 (95% CI, 0.36−0.91), respectively. Moreover, no significant differences were observed between US and MRI measurements in predicting the sizes of the gracilis and semitendinosus autografts. Preoperative US measurements of the target tendons were moderately correlated with the intraoperative autograft size. US imaging has a discriminative performance similar to that of MRI in predicting the autograft size. A standardized US scanning protocol is needed for future studies to minimize the variations in tendon measurements across different investigators and increase the comparability of US imaging with intraoperative findings.

Dynamic Ultrasound Assessment of the Anterior Tibial Translation for Anterior Cruciate Ligament Tears Diagnostic

The aim of our study was to investigate the accuracy of dynamic ultrasound assessment of the anterior tibial translation, in diagnosing anterior cruciate ligament tears, and to assess its test−retest reliability. Twenty-three patients (32 ± 8.42 years; 69.56% males) with a history of knee trauma and knee instability participated in the study. Knee ultrasound was performed by an experienced orthopedic surgeon. The anterior tibial translation was measured in both knees and differences between the injured and uninjured knee were calculated. Side-to-side differences > 1 mm were considered a positive diagnosis of an ACL tear. The anterior tibial translation values were 3.34 ± 1.48 mm in injured knees and 0.86 ± 0.78 mm in uninjured knees. Side-to-side differences > 1 mm were found in 22 cases (95.65%). The diagnosis accuracy was 91.30% (95%CI: 71.96−98.92%) and sensitivity 95.45% (95%CI: 77.15−99.88%). The intraclass correlation coefficient showed an excellent test−retest reliability (ICC3,1 = 0.97 for the side-to-side difference in anterior tibial translation). The study highlights the accuracy and reliability of the dynamic ultrasound assessment of the anterior tibial translation in the diagnosis of unilateral anterior cruciate ligament tears. Ultrasound assessment is an accessible imaging tool that can provide valuable information and should be used together with physical examination in suspected cases of ACL injuries.