How Many Radiographs Does It Take to Screen for Femoral Cam Morphology?: A Noninferiority Study.

PURPOSE: To compare a 2-view radiograph series (AP of the pelvis and 45° Dunn of the hip) with a 5-view radiograph series for sensitivity in identifying femoral cam morphology. MATERIALS AND METHODS: This is a retrospective review of consecutive patients with a 5-view radiograph series (AP pelvis and AP, 45° Dunn, frog lateral, and false profile of the affected hip) from 2016 to 2017. Three fellowship trained radiologists blindly and independently evaluated 2 views (AP pelvis and Dunn) for a femoral cam lesion, acetabular rim calcification, Tonnis grade, and important incidental findings. Two weeks later, the same assessment was made on all 5 views. A noninferiority test of the 2-view series vs the 5-view series for sensitivity in identifying femoral cam morphology was conducted. Individual reader sensitivity calculations were performed and agreement was determined with the kappa statistic. RESULTS: The 2-view series was noninferior to the 5-view series for cam identification (P value = 0.010). In comparing the 2-view vs 5-view series for individual readers, there was no difference in the sensitivities (84%-100% vs 85%-98%, P = 0.85-1.0) or specificities (11%-56% vs 7%-56%, P = 0.58-1.0) for cam identification. There was fair to excellent 2-view intrareader agreement (k = 0.38-0.93) and similar inter-reader agreement between the 2-view and 5-view (k = 0.33 vs 0.37). CONCLUSIONS: A 2-view radiograph series (AP pelvis and Dunn hip) is noninferior to a 5-view radiograph series for sensitivity in identifying femoral cam morphology.

Evaluation and Management of Hand, Wrist and Elbow Injuries in Ice Hockey.

Ice hockey continues to be a popular, fast-paced, contact sport enjoyed internationally. Due to the physicality of the game, players are at a higher risk of injury. In the 2010 Winter Olympics, men's ice hockey had the highest injury rate compared to any other sport. In this review, we present a comprehensive analysis of evaluation and management strategies of common hand, wrist, and elbow injuries in ice hockey players. Future reseach focusing on the incidence and outcomes of these hand, wrist and elbow injuries in ice hockey players is warranted.

Trends of Follow-Up Recommendations Made on Musculoskeletal MRI Reports.

OBJECTIVE. The purpose of this article was to analyze trends in follow-up recommendations made on musculoskeletal MRI reports. MATERIALS AND METHODS. An IRB-approved retrospective study identified 790 musculoskeletal MRI reports from our database between January 1, 2016, and January 1, 2018, containing follow-up recommendations made by the interpreting radiologist. Metadata were automatically extracted and classification of the recommendations was performed by manual review. Clinical outcome data were collected from the electronic health record. After exclusion criteria were applied, 654 reports were included in the study. Descriptive statistics, Fisher exact tests, and chi-square tests were used for analysis. RESULTS. Clinicians acknowledged 83% and followed 73% of the recommendations. Follow-up compliance varied with the type of recommendation made: 98% for clinical intervention versus 67% for additional imaging (p < 0.001). Subspecialties acknowledged and followed recommendations at different rates: 92% and 85% for internists versus 76% and 64% for orthopedists (p < 0.001 and p < 0.001), respectively. Patient age, practice setting, radiologist experience, recommendation conditionality, and specified follow-up time intervals made no difference in compliance rate (all p > 0.05). There was no difference in compliance rate among various pathologic findings of concern (p = 0.995). Compliance rate increased significantly after direct communication between the radiologist and clinician compared with when there was no direct communication (93% vs 71%, p < 0.001). Concern for neoplasm comprised the greatest number of unacknowledged recommendations (73%). CONCLUSION. Musculoskeletal MRI recommendations are followed independent of the finding of concern and compliance is lowest for requests of additional imaging. Direct communication improves compliance and may be particularly helpful for orthopedic referrers.

Bennett lesions in overhead athletes and associated shoulder abnormalities on MRI.

OBJECTIVE: To determine if a Bennett lesion and its size are associated with additional MRI shoulder abnormalities in an overhead athlete. MATERIALS AND METHODS: An IRB-approved retrospective review of our database from 1 January 2012 to 1 April 2018 identified 35 overhead athletes with a Bennett lesion on MRI. A control group consisting of 35 overhead athletes without a Bennett lesion were matched for age, level of play (professional vs non-professional), and type of study (arthrogram vs non-arthrogram). Each study was assessed independently by two MSK fellowship trained radiologists. The sizes of the Bennett lesions were measured. Each MRI was assessed for the presence of a labral tear, posterior glenoid cartilage abnormality, humeral head notching or cysts, and fraying or tear of the supraspinatus or infraspinatus tendons. Statistical analyses were performed using Student's t test, Fisher's exact test, and Chi-squared test. RESULTS: There was an increased incidence of posterior glenoid cartilage abnormalities in athletes with Bennett lesions vs those without (23% vs 3%, p value = 0.01). There was no difference in any other MRI abnormalities, including labral tears and findings of internal impingement between these two groups (p value range = 0.09-0.46). There was no association between the size of a Bennett lesion and the presence of glenoid cartilage lesions, labral tears, internal impingement, age, professional status, or need for surgery (p value range = 0.08-0.96). CONCLUSION: Symptomatic overhead athletes with Bennett lesions have an increased frequency of posterior glenoid cartilage abnormalities, but not labral tears or findings of internal impingement compared to those without Bennett lesions.

Effect of Analytics-Driven Worklists on Musculoskeletal MRI Interpretation Times in an Academic Setting.

OBJECTIVE. The objective of this study was to determine how use of analytics-driven worklists for MRI based on relative individual interpretation time affects the overall group interpretation time in an academic musculoskeletal practice. SUBJECTS AND METHODS. In this prospective study, interpretation times for all MRI studies signed by three musculoskeletal fellowship-trained radiologists during 2016 were calculated from initial study view and report signing times. Custom worklists were made for each radiologist with body parts ordered from the fastest to the slowest based on relative interpretation time. These worklists were then used for a trial period of 7 consecutive days. The difference in mean interpretation times between the trial period and baseline and the differences in volume distribution were calculated. Changes in individual interpretation time were assessed by z-score with statistical significance set at ≤ 0.05. RESULTS. Across all readers, total interpretation time decreased by a mean of 29.5 minutes per day during the trial period. Only two types of studies were read with an individual interpretation time significantly different from baseline (wrist studies for reader 1 were 10 minutes slower [p = 0.01] and cervical spine studies for reader 3 were 9 minutes faster [p < 0.01]). Volume distributions changed across various body parts (-3% to 4% for reader 1, -13% to 14% for reader 2, and -24% to 10% for reader 3). CONCLUSION. Analytics-driven worklists for MRI may decrease overall group interpretation time without significant alteration in individual speed, though a change in volume distribution is required.

Ulnar Collateral Ligament Insertional Injuries in Pediatric Overhead Athletes: Are MRI Findings Predictive of Symptoms or Need for Surgery?

OBJECTIVE: The purpose of this study was to determine whether ulnar collateral ligament (UCL) insertion below the articular margin (so-called T sign) exists in the pediatric population and whether MRI features can be used to identify insertional UCL injuries in overhead athletes that are symptomatic or require surgery. MATERIALS AND METHODS: Retrospective review of elbow MR images of patients younger than 21 years from 2011 to 2017 yielded 26 control subjects who were not overhead athletes and 97 overhead athletes. According to the clinical diagnosis, 50 of the overhead athletes had symptoms. Two radiologists evaluated the UCL for thickness, abnormal insertional signal intensity, insertion distance, and adjacent marrow or soft-tissue edema. Insertion distance was defined as the coronal length of any T sign measured from the articular margin. RESULTS: Mean insertion distance was greater in overhead athletes than in control subjects (1.42 vs 0.23 mm, p = 0.001) but not significantly different in athletes with symptoms compared with those without symptoms or in those who underwent operative treatment compared with those who did not. Mean UCL thickness was greater in overhead athletes than in control subjects (2.64 vs 1.74 mm, p < 0.0001), athletes with than those without symptoms (2.84 vs 2.41 mm, p = 0.005), and athletes who did versus those who did not undergo operative treatment (3.40 vs 2.73 mm, p = 0.011). Marrow (p = 0.002) and soft-tissue (p = 0.016) edema were found more frequently in athletes with symptoms. ROC analysis of UCL thickness and insertion distance as predictors of symptoms showed AUCs of 0.69 and 0.49, respectively. CONCLUSION: The T sign is likely not an anatomic variation but is a poor predictor of symptoms and need for surgery. Soft-tissue and marrow edema are more frequently seen in overhead athletes with symptomatic injuries and can aid in the diagnosis of clinically relevant injury.

Anterior Inferior Iliac Spine Morphology: Comparison of Symptomatic Hips With Femoroacetabular Impingement and Asymptomatic Hips.

OBJECTIVE: The objective of our study was to compare anterior inferior iliac spine (AIIS) morphology in symptomatic hips with femoroacetabular impingement (FAI) and in asymptomatic hips, determine the prevalence of impingement morphology in patients with a radiographic "crossover" sign, and identify potential risk factors for having impingement morphology. MATERIALS AND METHODS: For this retrospective study, we identified consecutive symptomatic hips with FAI (n = 54) and asymptomatic hips (n = 35) in patients who underwent CT from 2015 to 2017. Two radiologists blindly and independently evaluated 3D CT images of each hip and graded the AIIS morphology according to the Hetsroni classification scheme. The prevalence of AIIS morphology types was calculated. Associations of AIIS morphology types with symptoms and the crossover sign were evaluated with a chi-square test. A multivariable logistic regression determined risk factors for abnormal AIIS morphology (i.e., type 2 or 3). RESULTS: There was no difference in the prevalence of AIIS morphology types for symptomatic hips with FAI versus asymptomatic hips (p = 0.44) or for hips with a positive versus those with a negative crossover sign (p = 0.21). There was moderate interobserver agreement (κ = 0.44) and good-to-excellent intraobserver agreement (κ = 0.67 and 0.90) for grading AIIS morphology. Age, sex, femoral version, acetabular version, alpha angle, lateral center edge angle, and the crossover sign were not significant risk factors for abnormal AIIS morphology in patients with FAI (p = 0.11-0.79). CONCLUSION: There is no difference in AIIS morphology between symptomatic hips with FAI versus asymptomatic hips or between hips with and those without the radiographic crossover sign. Age, sex, and other FAI parameters are not risk factors for developing AIIS impingement morphology.

Preoperative Use of a 3D Printed Model for Femoroacetabular Impingement Surgery and Its Effect on Planned Osteoplasty.

OBJECTIVE: The purpose of this study was to determine the effect that preoperative use of 3D printed models has on planned osteoplasty for femoroacetabular impingement (FAI) surgery. MATERIALS AND METHODS: This experimental study utilizing retrospective data included 10 consecutive patients from July 1, 2013, to January 1, 2015, with a clinical diagnosis of FAI and imaging consisting of radiographs, CT scans, and MR images. Three-dimensional models of each patient's affected hip were printed to scale from CT data. Two orthopedic surgeons evaluated each patient in a routine preoperative manner. The effect of the 3D models in altering the planned osteoplasty was then determined. Proportions of osteoplasty change were calculated at various positions, and categoric variables were assessed with the chi-square test for independence. RESULTS: Proportions of osteoplasty changes ranged from 20% to 55% at femoral positions (greatest at lateral and depth positions) and 35-75% at acetabular positions (greatest at anterior and depth positions). More osteoplasty changes occurred in patients with alpha angles of 60° or more (p = 0.00030) and without a radiographic crossover sign (p = 0.0075). We found no difference in the proportion of osteoplasty changes when stratifying by lateral center edge angle and coxa profunda (p = 0.190 and 0.109, respectively). The planned osteoplasty was changed for at least one reader in 9/10 (90%) femurs and 10/10 (100%) acetabula. CONCLUSION: Use of 3D models in preoperative planning can change both the extent and location of planned osteoplasty for FAI surgery and is particularly influential in patients with alpha angles of 60° or more and without a radiographic crossover.

Shoulder Injuries in the Overhead-Throwing Athlete: Epidemiology, Mechanisms of Injury, and Imaging Findings.

The unparalleled velocity achieved by overhead throwers subjects the shoulder to extreme forces, resulting in both adaptive changes and pathologic findings that can be detected at imaging. A key biomechanical principle of throwing is achieving maximum external rotation, which initially leads to adaptive changes that may result in a pathologic cascade of injuries. In addition to the well-established concepts of glenohumeral internal rotation deficit and internal impingement, osseous and soft-tissue injuries of the shoulder unique to overhead athletes are illustrated. The epidemiology and biomechanics of throwing injuries are reviewed, and examples from the authors' institutional experience with competitive, collegiate, and professional baseball players are provided to demonstrate the constellation of unique imaging findings seen in overhead throwing athletes. Given the widespread popularity of baseball, and other sports relying on overhead throwing motions at all playing levels from recreational to professional, it is important for radiologists in various practice settings to be familiar with the special mechanisms, locations, and types of shoulder injuries seen in the overhead throwing population. © RSNA, 2018.

Adventures and Misadventures in Plastic Surgery and Soft-Tissue Implants.

Soft-tissue augmentation and implants are increasingly seen by the radiologist as more techniques emerge for a variety of indications and locations. Some surgical and implant procedures are performed for purely cosmetic reasons in otherwise healthy patients seeking to improve their body image, and some are performed for reconstruction after cancer or other chronic illnesses. Abdominoplasty, liposuction, and autologous fat grafting can be performed for abdominal and gluteal contouring. Injection of liquid injectable silicone has historically been fraught with legal issues, although it continues to be used for augmentation in a variety of anatomic locations. Newer solid silicone implants have revolutionized cosmetic and reconstructive muscular contouring. Subdermal implants placed by nonmedical professionals are relatively new and unrecognized within the medical establishment, although such implants have been described in the popular culture. Perhaps the most rapidly increasing segment of cosmetic procedures, however, is minimally invasive cosmesis in the form of soft-tissue fillers in the hands and face. Finally, the major principles of breast augmentation and penile implants are also reviewed. Regardless of the location and the type of implant, complications of plastic surgery and soft-tissue implants can generally be classified into the following categories: seroma, hematoma, infection, migration, vascular or nerve compression, fibrosis, foreign-body reaction, and rupture or breakdown. Key concepts include knowing the appropriate anatomic location and the normal postoperative appearance so that complications can be properly detected. A broad range of approved, off-label, and illicit plastic surgical and implant procedures are described and their complications illustrated with cases with classic imaging findings. ©RSNA, 2017.

Elbow Injuries in Pediatric Overhead Athletes.

OBJECTIVE: The purpose of this article is to discuss common elbow injuries found in pediatric athletes who participate in sports that entail overhead movements with focus on mechanism, clinical features, imaging appearance, and treatment options. CONCLUSION: Elbow injuries are commonly seen in pediatric overhead athletes and have been on the rise owing to the increased participation in and demand of youth sports. Imaging plays a critical role in identifying the type and severity of injury, which helps to determine appropriate treatment options.

Elbow Injuries in Adult Overhead Athletes.

OBJECTIVE: The purpose of this article is to review common elbow injuries found in overhead athletes with focus on mechanism, clinical features, imaging appearance, and treatment options. CONCLUSION: The overhead throwing motion subjects the elbow to a variety of complex forces, which places both osseous and soft-tissue structures at high risk for injury.

The Combination of the Tunnel View and Weight-Bearing Anteroposterior Radiographs Improves the Detection of Knee Arthritis.

Imaging used for the evaluation of knee pain has historically included weight-bearing anteroposterior (AP), lateral, and sunrise radiographs. We wished to evaluate the utility of adding the weight-bearing (WB) posteroanterior (PA) view of the knee in flexion. We hypothesize that (1) the WB tunnel view can detect radiographic osteoarthritis (OA) not visualized on the WB AP, (2) the combination of the AP and tunnel view increases the radiographic detection of OA, and (3) this may provide additional information to the clinician evaluating knee pain. We retrospectively reviewed the WB AP and tunnel view radiographs of 100 knees (74 patients) presenting with knee pain and analyzed for evidence of arthritis. The combination of the WB tunnel view and WB AP significantly increased the detection of joint space narrowing in the lateral (p < 0.001) and medial (p = 0.006) compartments over the AP view alone. The combined views significantly improved the identification of medial subchondral cysts (p = 0.022), sclerosis of the lateral tibial plateau (p = 0.041), and moderate-to-large osteophytes in the medial compartment (p = 0.012), intercondylar notch (p < 0.001), and tibial spine (p < 0.001). The WB tunnel view is an effective tool to provide additional information on affected compartments in the painful knee, not provided by the AP image alone.

Shoulder Arthroplasty, from Indications to Complications: What the Radiologist Needs to Know.

The replaced shoulder is increasingly encountered by the radiologist, both on a dedicated and incidental basis, in this era of the growing population of aging patients wishing to preserve their mobility and function. Knowledge of the normal biomechanics of the glenohumeral joint-particularly the function of the rotator cuff and the unique relationship of the humeral head to the glenoid-is essential for understanding the need for shoulder replacement and its subsequent complications, because the intent of shoulder arthroplasty is to approximate the normal joint as closely as possible. The most common indications for shoulder arthroplasty are osteoarthritis, inflammatory arthritis, proximal humerus fractures, irreparable rotator cuff tears, rotator cuff arthropathy, and avascular necrosis of the humeral head. Knowledge of the key imaging features of these indications helps facilitate a correlative understanding between the initial diagnosis and the choice of which type of arthroplasty is used-total shoulder arthroplasty, reverse total shoulder arthroplasty, or partial joint replacement (humeral head resurfacing arthroplasty or hemiarthroplasty). The preoperative requirements and usual postoperative appearance of each arthroplasty type are summarized, as well as the complications of shoulder arthroplasty, including those unique to or closely associated with each type of arthroplasty and those that can be encountered with any type of shoulder arthroplasty.

Diagnostic accuracy of noncontrast MRI for detection of glenohumeral cartilage lesions: a prospective comparison to arthroscopy.

BACKGROUND: The purpose of this study was to determine the prevalence of glenohumeral articular cartilage lesions in patients with rotator cuff tendinopathy and to assess the accuracy of noncontrast magnetic resonance imaging (MRI) in detecting these defects compared with the "gold standard" of arthroscopy. METHODS: Noncontrast MRI studies obtained in 84 consecutive patients undergoing shoulder arthroscopy for rotator cuff tendinopathy (mean age, 54.8 years; range, 17-82 years) were prospectively evaluated for glenohumeral cartilage lesions. Two fellowship-trained, experienced musculoskeletal radiologists were blinded from the arthroscopic findings and independently evaluated the glenoid and humeral head cartilage on 2 separate occasions. RESULTS: At arthroscopy, cartilage lesions of the humeral head were detected in 23 patients (frequency, 27.4%), and glenoid cartilage lesions were found in 20 patients (frequency, 23.8%). For detection of a humeral lesion on MRI, the radiologists' combined accuracy was 78%, sensitivity was 43%, and specificity was 91%. The combined accuracy for detection of glenoid lesions on MRI was 84%, sensitivity was 53%, and specificity was 93%. Combining the readers, low-grade lesions (International Cartilage Repair Society grades 1 and 2) of the glenoid and humerus were read as negative on MRI in 63% and 86% of cases, respectively. CONCLUSION: Overall accuracy of noncontrast MRI for detection of glenohumeral articular cartilage lesions is good; however, interpretation is reader dependent, and accuracy is significantly reduced for detection of low-grade lesions. On the basis of these findings, we recommend that patients with rotator cuff tendinopathy undergoing arthroscopy be informed that the presence and severity of cartilage lesions may be underestimated on MRI.

Sonographic evaluation of femoral trochlear cartilage in patients with knee pain.

OBJECTIVES: The purpose of this study was to investigate whether routine clinical sonographic evaluation of femoral trochlear cartilage can identify abnormalities in patients with knee pain. METHODS: Short-axis sonograms of the femoral trochlear cartilage were obtained from 20 symptomatic knees in 20 consecutive patients (16 women and 4 men; mean age, 54 years; range, 35-75 years) and 20 knees in 10 asymptomatic control participants (7 women and 3 men; mean age, 52 years; range, 31-74 years). Articular cartilage thickness was measured at 3 locations in each knee, and thickness at each site was compared between patients and controls. Subsequently, images from patients and controls were randomly assorted and evaluated by 3 blinded musculoskeletal radiologists, who independently evaluated the femoral trochlear cartilage in each sonogram for cartilage clarity, grade, and presence or absence of cartilage calcifications, osteophytes, and subchondral bony irregularity. The radiologists were instructed to rate the most severe lesion in each evaluated region (medial trochlea, trochlear notch, and lateral trochlea). Cartilage clarity was defined as how well the cartilage borders could be distinguished from the overlying intra-articular soft tissues, and grade was defined as the severity of focal cartilaginous lesions. RESULTS: Using the Student t test, there was no significant difference (P > .05) between cartilage thickness in patients and controls for any location measured. However, using repeated measures analysis of variance, there were significant differences (P = .02) for both decreased cartilage clarity (df = 1/28; F = 5.76) and increased grade (df = 1/28; F = 5.77) in patients. There was also a nonsignificant (P > .05) trend toward more frequent calcifications, osteophytes, and bony irregularity in patients. CONCLUSIONS: Routine clinical sonography can identify femoral trochlear cartilage abnormalities in patients with knee pain and therefore can be a useful adjunct to other imaging tests for identifying arthritic changes in the knee.