Anatomic Relationship and Imaging Relevance of the Perforating Branches of the Peroneal Vessels to the Anterior Talofibular Ligament

Background

Patients frequently present to the emergency department after ankle injuries, and the anterior talofibular ligament (ATFL) is commonly damaged. Musculoskeletal ultrasound (US) can help to make a rapid diagnosis. There is a paucity of literature describing techniques to image the ATFL with US, and the complex ankle anatomy and potential pitfalls make imaging challenging.

Sonographic Findings of Chondral Avulsion Fractures of the Lateral Ankle Ligaments in Children

In this series, we aimed to describe the sonographic findings of chondral avulsion fractures that develop concomitant with lateral ankle ligament injury in children. We performed stress sonography during a manual anterior drawer stress procedure of the ankle in 9 skeletally immature patients who had recently had a lateral ankle sprain. Echo videos were obtained through the course of treatment, and all videos were reviewed. We elucidated the common features of chondral avulsion fractures of the lateral ankle ligaments in the children. The features of avulsion fractures on conventional sonography included absence of a fracture with hyperechoic spots (sonographic occult fracture type), cortical discontinuity with hyperechoic spots (cortical disruption fracture type), fracture line in the cortical bone (double‐line fracture type), and a step‐off deformity of the cortical bone with cartilage (displaced fracture type). In contrast, the features of chondral fractures on stress sonography included abnormal motion of the chondral lesions and mobility/fluidity of hyperechoic spots along the chondral fracture site. The presence of hyperechoic spots around the chondral lesion is an important sonographic sign for diagnosing chondral fractures concomitant with ankle lateral ligament injury. Hence, we believe that stress sonography should be considered for the detection of chondral fractures concomitant with radiographically negative ankle lateral ligament injuries in skeletally immature patients with lateral ankle pain and ankle sprains, if hyperechoic spots are present in the cartilage of the distal fibula.     

高频超声诊断距腓前韧带损伤的临床价值

目的 分析不同分型距腓前韧带损伤的影像特征,探讨高频超声对距腓前韧带损伤的诊断价值。方法 收集我院疑似单侧距腓前韧带损伤患者152例,均行高频超声检查并进行分型,测量并比较健侧与患侧距腓前韧带厚度,以MRI检查结果为金标准,绘制高频超声诊断距腓前韧带损伤的受试者工作特征（ROC）曲线,并计算其诊断效能;采用Kappa检验分析高频超声与MRI检查结果的一致性;Spearman相关分析法分析患侧距腓前韧带厚度与距腓前韧带损伤分型的相关性。结果 152例患者中,MRI诊断距腓前韧带损伤82例,其中Ⅰ级47例、Ⅱ级24例、Ⅲ级11例。高频超声诊断距腓前韧带损伤84例,其中Ⅰ型44例、Ⅱ型26例、Ⅲ型14例。ROC曲线分析显示,高频超声诊断距腓前韧带损伤的敏感性为95.12%,特异性为91.43%,阳性预测值为92.86%,阴性预测值为94.12%,ROC曲线下面积为0.933(95%可信区间0.886～0.979)。高频超声测得患侧距腓前韧带厚度为（2.77±0.85）mm,高于健侧（2.00±0.44）mm,差异有统计学意义（P<0.05）;其中Ⅰ型、Ⅱ型、Ⅲ型损伤的患侧距腓前韧带厚度...     

Diagnosis of Simultaneous Acute Ruptures of the Anterior Cruciate Ligament and Posterior Cruciate Ligament Using Point-of-Care Ultrasound in the Emergency Department

Background

Patients with acute anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries from sport-related activities are frequently seen in the emergency department (ED). However, knee instability tests are known to show variable sensitivity and specificity. These tests would also have limited functionality in patients with severe pain and swelling in the knee.

Sonography of the Pronator Teres: Normal and Pathologic Appearances

The pronator teres muscle is rarely examined during a routine sonographic examination of the elbow joint. Nevertheless, it can be affected by a variety of conditions, including trauma and tumors, and can be implicated in compression of the median nerve. This pictorial essay first illustrates the anatomy and biomechanics of the pronator teres. Then we present the sonographic technique for examination, normal sonographic appearance, and anatomic variations of the pronator teres and adjacent structures as well as sonography of their main disorders. Normal and pathologic sonographic appearances are correlated with magnetic resonance imaging and radiographic results.     

Considerations of the Posterior Tibial Slope in Anterior Cruciate Ligament Reconstruction: a Scoping Review

Purpose of ReviewThe significance of posterior tibial slope (PTS) in the setting of anterior cruciate ligament (ACL) injury and reconstruction has been increasingly recognized in recent years. The purpose of this article is to review the biomechanical and clinical studies of PTS in conjunction with ACL injuries, providing an evidence-based approach for the evaluation and management of this patient population.Recent FindingsSeveral biomechanical and clinical studies suggest that PTS > 12° may be considered with increased strain on the native ACL fibers (or reconstructed graft) and greater anterior tibial translation, predisposing patients to a recurrent ACL injury. The increased rates of ACL injury and graft failure seen in those with increased PTS have garnered attention to diagnose and surgically address increased PTS in the revision ACL setting; however, the role of a slope-reducing high tibial osteotomy (HTO) in primary ACL reconstruction (ACL-R) has yet to be defined. Various HTO techniques to decrease PTS during revision ACL-R have demonstrated promising outcomes, though conclusions are limited by the multifactorial nature of revision surgery and concomitant procedures performed.SummaryRecent evidence suggests that increased PTS is a risk factor for failure following ACL-R, which may be mitigated by a slope-reducing HTO. Further investigation is needed to elucidate abnormal PTS values and to determine appropriate indications for a slope-reducing HTO in primary ACL-R.     

The Role of the RNFA in Anterior Cruciate Ligament Graft Preparation

Anterior cruciate ligament (ACL) reconstruction is one of the most commonly performed orthopedic procedures in the United States. Repair of the ACL often requires the use of autografts or allografts, and the RN first assistant (RNFA) often is the team member responsible for preparing the graft. Common grafts used in ACL repair include bone-patellar tendon-bone, hamstring, Achilles tendon, quadriceps tendon, and tibialis anterior tendon. The RNFA must be competent in preparing all of these grafts and in understanding the advantages and disadvantages of using each graft, such as the reasons for graft choice, and must ensure that all graft-related supplies and equipment are available and ready for use. The ability to prepare all graft types expands treatment options, reduces surgical time, and enhances the role of the RNFA.     

A Novel Approach to Measure Variability in the Anterior Cruciate Ligament Deficient Knee During Walking: The Use of the Approximate Entropy in Orthopaedics

Objective. The evaluation of variability of biological rhythmic activities through measures such as Approximate Entropy (ApEn) has provided important information regarding pathology in disciplines such as cardiology and neurology. This research lead to the “loss of complexity hypothesis” where decreased variability is associated with loss of healthy flexibility rendering the system more rigid and unable to adapt to stresses. ApEn as a measure of variability and complexity, correlates well with pathology while, in some cases, it is predictive of subsequent clinical changes. The study of human gait could benefit from the application of ApEn since it is also a rhythmical oscillation. Our aim was to assess the variability of the ACL deficient knee, since ACL rupture is a common musculoskeletal injury and is accompanied by altered gait patterns and future pathology in the joint. We hypothesized that the ACL deficient knee will exhibit more regular and less variable walking patterns than the contralateral intact knee. Methods. Ten subjects with unilateral deficiency walked on a treadmill at their self-selected speed, 20% faster, and 20% slower, while kinematics were collected (50 Hz) from 80 consecutive strides for each condition. The ApEn of the resulted knee joint flexion-extension time series was calculated. Results. Significantly smaller ApEn values were found in the ACL deficient knee when compared with the contralateral intact (F = 5.57, p = 0.022), for all speeds. ApEn values significantly increased (F = 5.79, p = 0.005) with increases in walking speed. Conclusions. The altered properties of the ACL deficient knee, which exhibits more regular and less variable patterns than the contralateral intact knee, may decrease the adaptability of the system rendering it less able to adjust to perturbations. This could explain the increased future pathology found in the deficient knee. ApEn can be an important tool in assessing pathology and therapeutic interventions in orthopaedics.     

Role of Sonography in the Diagnosis and Treatment of Common Peroneal Neuropathy Secondary to Fabellae

The fabella is a sesamoid bone situated in the posterolateral knee, which may contribute to posterolateral knee pain by impinging on the adjacent common peroneal nerve (CPN). Although anatomic studies have established an relationship between the fabella and CPN, we present 4 cases of posterolateral knee pain radiating into the anterolateral leg in which sonography was able to determine the source of the pain as CPN compression by an adjacent fabella. In 2 of these cases, resolution of symptoms was achieved with ultrasound‐guided CPN blocks, whereas 1 case was surgically treated, and another was managed with oral analgesics. These cases illustrate the utility of diagnostic and interventional sonography in the evaluation and treatment of posterolateral knee pain secondary to fabellar impingement of the CPN.     

Ultrasonography of the Sural Nerve: Normal and Pathologic Appearances

Ultrasonography (US) of peripheral nerves has gained wide popularity because of the increased definition of modern high‐frequency electronic transducers, as well as the well‐known advantages of US, which include easy availability, low cost, and the possibility of realizing a dynamic examination. Traditionally, US has been deployed to assess the major nerves of the limbs. More recently, US has also been used to assess the normal appearance and pathologic changes of smaller subcutaneous nerves. The sural nerve is a small sensory nerve in the subcutaneous tissues of the calf that can be affected by a variety of disorders. This pictorial essay illustrates the normal anatomy of the sural nerve, the technique for its examination by US, as well as the US appearance of its main pathologic changes.     

Quantitative Ultrasound Assessment of the Achilles Tendon Under Varied Loads

This Institutional Review Board–approved pilot study attempted to detect the correlation between ultrasound shear wave elastographic measures and tendon loads. Five male fresh‐frozen cadaveric Achilles tendons were loaded in 10‐N increments from 0 to 60 N. Shear wave velocity measurements within each Achilles tendon were obtained at each load in longitudinal and transverse orientations. Shear wave velocity measurements were correlated with tendon tension on both longitudinal and transverse plane imaging and showed moderate and strong positive correlation coefficients, respectively. Of note, limitations of the clinically available shear wave elastographic technology for measuring high velocities exist.