Zachariassenlist5863

The capsular and ligamentous structures of the glenohumeral joint are important for stability of the shoulder. These structures are best evaluated by MR imaging. Familiarity with normal and abnormal appearance of the capsular structures of the shoulder is important to ensure that important pathology is not overlooked. Injury to the capsular structures can occur in the setting of trauma and most commonly involves the inferior glenohumeral ligament and axillary pouch. Adhesive capsulitis is a common inflammatory condition with characteristic imaging features that should be considered in the absence of alternative diagnoses. In this article, the authors aim to focus on the challenges of interpreting shoulder MR imaging in the throwing athlete with an approach formed by evidence-based literature and clinical experience, with a particular focus on superior labrum tears. MR imaging of the postoperative shoulder after instability surgery is challenging. The radiologist must be familiar with surgical procedures, altered anatomy, and expected postoperative findings for correct interpretation of normal findings versus a true pathology. Artifacts from metallic hardware or abrasions further complicate MR image interpretation, but are reduced with metal artifact reduction techniques. This article focuses on capsulolabral surgery, bone block transfers, and humeral bone loss procedures in patients with shoulder instability and their postoperative imaging evaluation. Surgical procedures and common complications are explained, and normal and pathologic postoperative imaging findings are presented. Posterior shoulder instability is often hard to diagnose with clinical examination. Patients generally present with vague pain, weakness, and/or joint clicking but less frequently complaining of frank sensation of instability. Imaging examinations, especially MR imaging and magnetic resonance arthrography, have a pivotal role in the identification and management of this condition. This review describes the pathologic micro/macrotraumatic magnetic resonance features of posterior shoulder instability as well as the underlying joint abnormalities predisposing to this condition, including developmental anomalies of the glenoid fossa, humeral head, posterior labrum, and capsular and ligamentous structures. Most first-time anterior glenohumeral dislocations occur as the result of trauma. Many patients suffer recurrent episodes of anterior shoulder instability (ASI). The anatomy and biomechanics of ASI is addressed, as is the pathophysiology of capsulolabral injury. The roles of imaging modalities are described, including computed tomography (CT) and MR imaging with the additional value of arthrography and specialized imaging positions. Advances in 3D CT and MR imaging particularly with respect to the quantification of humeral and glenoid bone loss is discussed. The concepts of engaging and nonengaging lesions as well as on-track and off-track lesions are examined. learn more MR imaging interpretation following rotator cuff repair can be challenging and requires familiarity with various types of rotator cuff tear, their surgical treatments, normal postoperative MR imaging appearance, and complications. This article reviews the common surgical procedures for the reparable and nonreparable massive rotator cuff tears, their expected postoperative MR imaging findings, and imaging appearance of a range of complications. The cause of rotator cuff tears is multifactorial with both intrinsic and extrinsic contributing factors. Understanding the normal MR anatomy of the rotator cuff and using an appropriate search pattern can help readers identify common pathologic conditions. Accurate designation using classification systems for tear thickness, size, and degree of retraction and muscle fatty infiltration and atrophy are important in guiding surgical management. Knowledge of common disease locations for the rotator cuff tendons can help focus reader searches and increase sensitivity. MR imaging is the standard diagnostic modality that provides a comprehensive and accurate assessment for both osseous and soft-tissue pathologic conditions of the shoulder. This article discusses standard MR imaging and arthrography protocols used routinely in clinical practice, as well as more innovative sequences and reconstruction techniques, facilitated by the increasing availability of high-field-strength magnets and multichannel phased array surface coils and incorporation of artificial intelligence. These exciting innovations allow for a more detailed and diagnostic imaging assessment, improvements in image quality, and more rapid image acquisition. BACKGROUND Periacetabular osteotomy (PAO) is a hip preserving procedure performed often in younger, highly active patients. However, counseling patients is difficult, as there are limited data regarding activity level after PAO. The purpose of this study is to analyze the physical activity levels after PAO in a large, prospective multicenter cohort. METHODS Prospectively collected data from a multicenter study group included 359 hips treated by PAO for hip dysplasia at a mean age of 25.1 years. Patient demographics, radiographic measures, operative data, and clinical outcomes were evaluated preoperatively, at 1 year, and at minimum 2 years postoperatively. Activity level was assessed with the University of California Los Angeles (UCLA) activity score, and patients were stratified into low activity, moderate activity, and high activity groups based on preoperative function. RESULTS Compared to preoperative scores across the complete cohort, postoperative UCLA scores were improved on average 0.6 points at final follow-up (P = .001). The low activity and moderate activity groups had significant improvement in UCLA scores (P less then .001 and P = .0007, respectively), while the high activity groups saw a significant decrease in UCLA activity scores (P less then .0001). Modified Harris Hip Score, Hip Disability and Osteoarthritis Score Pain, and Hip Disability and Osteoarthritis Score Sports and Recreation scores were significantly improved across all preoperative activity levels. Multivariable linear regression (r2 = 0.45) confirmed prior ipsilateral surgery as a predictor for change in UCLA score (P = .002). CONCLUSION Overall, these data suggest that consistent improvements in activity level and function can be expected following PAO surgery, with greater gains experienced by patients with lower preoperative levels of activity.