Multifid Iliopsoas Tendons Are More Common in Patients With Painful Snapping Iliopsoas Tendons

Purpose

To retrospectively determine the prevalence of multifid tendons in a population of patients who underwent iliopsoas release for painful snapping iliopsoas tendons.

Methods

Patients who underwent iliopsoas release for painful snapping iliopsoas tendons were retrospectively identified from a database of patients who had undergone arthroscopic hip surgery performed by a single surgeon between 2011 and 2020. Patients who had incomplete data or who underwent prior fracture fixation, joint arthroplasty, pelvic surgery, or other interventions for snapping hip were excluded. Magnetic resonance imaging (MRI) and operative reports were reviewed and compared with those of an age-matched control group of patients who had undergone hip or pelvic MRI examinations in the past year for different indications.

Results

This study included 91 patients (78 female and 13 male patients; mean age, 23.3 years) who were treated operatively for painful snapping hip and 78 controls (54 female and 24 male patients; mean age, 28.4 years) who received hip or pelvic MRI for other indications. Among the patients who underwent iliopsoas release, there were 5 unifid iliopsoas tendons (5.5%) compared with 86 multifid iliopsoas tendons (94.5%) when classified with MRI whereas operative examination showed 19 unifid tendons (20.9%) compared with 72 multifid tendons (79.1%, P < .001). When the MRI scans of the operative group were compared with the MRI scans of the control group, the patients who underwent surgery for painful snapping hip had a higher rate of multifid tendons (94.5% of operative hips compared with 69.2% of control right hips [P < .001] and 74.4% of control left hips [P < .001]). However, when the operative reports were used to classify the iliopsoas tendon, there was no significance between the operative and control groups (79.1% of operative hips had multifid tendons compared with 69.2% of control right hips [P = .141] and 74.4% of control left hips [P = .464]).

Conclusions

For patients with symptomatic snapping hip undergoing iliopsoas lengthening, multifid iliopsoas tendons are more prevalent than in a control population.

Level of Evidence

Level IV, prognostic case series.

Hearing and Seeing Nerve/Tendon Snapping: A Systematic Review on Dynamic Ultrasound Examination

Nerve/tendon snapping can occur due to their sudden displacement during the movement of an adjacent joint, and the clinical condition can really be painful. It can actually be challenging to determine the specific anatomic structure causing the snapping in various body regions. In this sense, ultrasound examination, with all its advantages (especially providing dynamic imaging), appears to be quite promising. To date, there are no comprehensive reviews reporting on the use of dynamic ultrasound examination in the diagnosis of nerve/tendon snapping. Accordingly, this article aims to provide a substantial discussion as to how US examination would contribute to 'seeing' and 'hearing' these pathologies' different maneuvers/movements.

Dynamic musculoskeletal ultrasound: slipping rib, muscle hernia, snapping hip, and peroneal tendon pathology

Dynamic musculoskeletal ultrasound is an important diagnostic tool that allows the practitioner to observe soft tissue structures over a range of motion and identify pathology not diagnosed on other modalities. Familiarity with this modality allows health care practitioners to appropriately refer patients for this type of examination. This article will review several indications for dynamic ultrasound imaging, including slipping rib, muscle hernia, snapping hip, and peroneal tendon pathology. The examination technique and expected findings for common pathology in each location are discussed.

ACR Appropriateness Criteria® Chronic Hip Pain: 2022 Update

Chronic hip pain is a frequent chief complaint for adult patients who present for evaluation in a variety of clinical practice settings. Following a targeted history and physical examination, imaging plays a vital role in elucidating the etiologies of a patient's symptoms, as a wide spectrum of pathological entities may cause chronic hip pain. Radiography is usually the appropriate initial imaging test following a clinical examination. Depending on the clinical picture, advanced cross-sectional imaging may be subsequently performed for further evaluation. This documents provides best practice for the imaging workup of chronic hip pain in patients presenting with a variety of clinical scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Imaging of Anatomical Variants Around the Hip

Considering the current widespread use of imaging as an integral part of managing hip pain, variable hip geometries and anatomical variants are increasingly being detected. These variants are commonly found in the acetabulum and proximal femur, as well as the surrounding capsule-labral tissues. The morphology of specific anatomical spaces confined by the proximal femur and the bony pelvis may also vary significantly among individuals. Familiarity with the spectrum of imaging appearances of the hip is necessary to identify variant hip morphologies with or without potential clinical relevance and reduce an unnecessary work-up and overdiagnosis. We describe anatomical variations and variable morphologies of the bony structures comprising the hip joint and the soft tissues, around the hip. The potential clinical significance of these findings is further analyzed in conjunction with the patient's profile.

Localized tenosynovial giant cell tumor: a rare case of snapping hip

We report on a 40-year-old male with a 9-month-long history of snapping of his right hip caused by a previously undescribed etiology of internal extra-articular snapping hip, namely due to a localized tenosynovial giant cell tumor. Both dynamic ultrasound evaluation and MRI proved to be crucial in the diagnosis of this rare entity. Auto-provocation of the snapping showed an anterior hip mass moving posteriorly to the psoas tendon which elucidated the pain and clicking sensation. Subsequent MRI demonstrated a peripheral low-intensity rim due to hemosiderin deposition around the synovial mass which is indicative for pigmented villonodular tenosynovitis. Treatment consisted of arthroscopic shaver burr resection. Immediately postoperatively, the snapping sensation could not be provoked anymore by the patient. The purpose of reporting on this case report is to emphasize several successive learning points. First, dynamic ultrasound aids in diagnosis and differentiation of the types of snapping hip. Second, specific MRI features are suggestive of tenosynovial giant cell tumor, recognizing these traits may prevent delayed diagnosis and subsequent aggravated clinical course. Third, localized pigmented villonodular tenosynovitis around the hip may present as an internal extra-articular snapping hip and is of consideration in the differential diagnosis of recurrent snapping hip.

US and MRI of Pelvic Tendon Anatomy and Pathologic Conditions

The bony pelvis serves as the attachment site for a large number of powerful muscles and tendons that drive lower extremity movement. Organizing the pelvic tendons into groups that share a common function and anatomic location helps the radiologist systematically evaluate these structures for injury, which can be caused by repetitive stress, acute trauma, or failure of degenerated tissues. Tears of the anteromedial adductors around the pubic symphysis and anterior flexors traversing anterior to the hip principally affect younger male athletes. Tears of the lateral abductors and posterior extensors are more common in older individuals with senescent tendinosis. The deep external rotators are protected and rarely injured, although they can be impinged. Imaging of the pelvic tendons relies primarily on US and MRI; both provide high spatial and contrast resolution for soft tissues. US offers affordable point-of-care service and dynamic assessment, while MRI allows simultaneous osseous and articular evaluation and is less operator dependent. While the imaging findings of pelvic tendon injury mirror those at appendicular body sites, radiologists may be less familiar with tendon anatomy and pathologic conditions at the pelvis. The authors review pertinent anatomy and imaging considerations and illustrate common injuries affecting the pelvic tendons. Online supplemental material is available for this article. ^©RSNA, 2022.

Female Athlete Hip Injuries: A Narrative Review

OBJECTIVE

In this narrative review, we highlight sex-specific anatomic and biomechanical features of the hip region in female athletes, as well as the potential impact of these characteristics on observed disparities in both intra-articular and extra-articular injury patterns between female and male athletes. It is our goal to broaden the scope of knowledge related to hip pathology in active female athletes among sports medicine providers with the hope of better optimizing sport participation and performance in female athletes.

DATA SOURCES

A literature review was conducted using PubMed database and Google Scholar search engine. Search terms included sport, female, athlete, sex differences, injury, hip, and all diagnoses discussed in this review. Cross-reference of these articles identified additional resources.

MAIN RESULTS

Sex-specific differences in both static design and dynamic function contribute to disparities in hip injury patterns between female and male athletes. Intra-articular injuries, including labral and ligamentum teres pathology, as well as extra-articular injuries, including iliopsoas tendon dysfunction, gluteal and proximal hamstring tendinopathy, ischiofemoral impingement, bone stress injuries, and certain nerve entrapment syndromes, seem to affect female athletes more commonly than male counterparts.

CONCLUSIONS

Given unique anatomic and functional considerations, the growing population of female athletes worldwide warrants specialized care and consideration. Potential predisposition to specific hip injuries should be taken into consideration during diagnostic evaluation of hip pain in the female athlete.

Hip Pain: Imaging of Intra-articular and Extra-articular Causes

Hip pain is a common and complex clinical entity. The causes of hip injuries in athletes are many and diverse, requiring efficient, accurate diagnosis for proper management. Imaging is an important step in the clinical evaluation of hip pain, and familiarity with multiple imaging modalities as well as characteristic imaging findings is a helpful tool for sports medicine clinicians. This article discusses imaging recommendations and gives imaging examples of common causes of intra-articular and extra-articular hip pain including femoroacetabular impingement, labral tears, cartilage defects, ligamentum teres injuries, snapping hip syndrome, femoral stress injuries, thigh splints, athletic pubalgia, avulsion injuries, and hip dislocation.

Hip Flexor Injuries in the Athlete

Athletic injuries to the hip flexors and iliopsoas have been described in populations across all levels of competitive sports. Overall estimates of hip flexor pathology have ranged from 5% to 28% of injuries among high-risk sport specific groups. Although most of these injuries are successfully treated with conservative management, and high rates of return to play are observed, significant rehabilitation time can be involved. As the understanding of hip pathology with imaging modalities such as MRI has advanced, greater importance has been placed on accurately diagnosing hip flexor injuries and initiating rehabilitation protocols early to minimize time loss from sport.

Hip Imaging and Injections

Athletic injuries of the hip often require radiographs and advanced imaging for diagnosis. Plain radiographs evaluate for osseous injury, provide a structural context behind an athlete's symptoms and examination, and offer a backdrop for interpretation of advanced imaging. An understanding of normal anatomy, imaging findings, and radiographic measurements allows for recognition of pathoanatomy and ability to diagnose accurately. Advanced imaging modalities, including magnetic resonance imaging, computed tomography, and ultrasonography, each play a role in evaluation of the athlete's hip. Although MRI and CT provide high-resolution imaging of the hip, ultrasonography offers the unique ability to perform dynamic imaging and guided injections.

Iliopsoas Muscle/Tendon Proportions at Three Levels of Described Arthroscopic Tenotomy: An Anatomic Study in Fresh Cadaveric Specimens

Purpose

To calculate the iliopsoas muscle/tendon ratio at 3 levels of arthroscopic iliopsoas tenotomy sites in fresh cadaveric specimens.

Methods

An anatomic study design was performed using 16 iliopsoas musculotendinous units from the level of the hip joint to their insertion on the lesser trochanter. All specimens came from 16 fresh cadaveric specimens (10 male, 6 female), with a median age of 41 years (range 31-55.25 years). Circumferential measurements of the composite musculotendinous unit and the iliopsoas tendon were then made at the lesser trochanter insertion, the site of transcapsular tenotomy, and the site of tenotomy at the level of the labrum. Anatomical variance of the iliopsoas tendon at the insertion on the lesser trochanter and muscular extension below the lesser trochanter level also were described. The difference between the median circumference of the iliopsoas musculotendinous units or the isolated tendons at the 3 levels was calculated.

Results

The median circumference of the iliopsoas musculotendinous unit at the level of the labrum, orbicularis zone (transcapsular tenotomy site), and the lesser trochanter was 140.9 mm (range 137.9-148.9), 136.7 mm (range 132.9-140), and 99.5 mm (range 96.5-104.8), respectively. The median circumference of the iliopsoas tendon at these same levels was 25.6 mm (range 22.7-33.7), 28.9 mm (range 25.1-32.2), and 30.9 mm (range 27.9-36.1), respectively. Accordingly, the proportions of the iliopsoas muscle/tendon at the level of the labrum, the transcapsular tenotomy site, and the lesser trochanter insertion were 18% tendon/82% muscle, 21% tendon/79% muscle, and 31% tendon/69% muscle, respectively.

Conclusions

The proportions of the iliopsoas muscle/tendon at the level of the labrum, the transcapsular tenotomy site and the lesser trochanter insertion were 18% tendon/82% muscle, 21% tendon/79% muscle, and 31% tendon/69% muscle, respectively. The distal muscular projection below the tendinous insertion on the lesser trochanter may maintain the functional connection of the iliopsoas between origin and insertion even after releasing the tendon.

Clinical relevance

This finding may have implications for a new understanding of arthroscopic tenotomy of the iliopsoas around the hip, as previously described muscle/tendon proportions were not calculated in fresh cadavers.

Sonographic 'flash': A case report of a new sign in dynamic ultrasound of extra-articular snapping hip and knee

Snapping phenomena at the hip and knee are common clinical presentations in the general population and athletes. Dynamic ultrasound is a useful tool in the evaluation of these syndromes, especially when intra-articular pathology has been excluded. We report on a new ultrasound sign, the 'sonographic flash', which identified the source of audible snapping in two cases where snapping phenomena were present.

Bifid iliopsoas tendon as a cause for internal snapping hip syndrome: A case report

Snapping hip syndrome, or coxa saltans, can result in significant clinical manifestations in patients including pain and limited mobility. A variety of both intra- and extra-articular pathologies have been implicated in snapping hip, including an anatomic variant known as the bifid iliopsoas tendon which has been briefly described in the literature. We report a case of a bifid iliopsoas tendon leading to internal snapping hip syndrome which was ultimately successfully treated with surgical release, including review of the clinical presentation, pathophysiology, and dynamic sonographic findings.

Ultrasound-Guided Iliopsoas Tendon Release: A Cadaveric Investigation

BACKGROUND

The iliopsoas is a common source of anterior hip pain. Refractory cases may require surgical intervention, with reported complication rates ranging from 3% to 50%. Development of a minimally invasive, outpatient method of iliopsoas tendon release is desirable and may reduce costs, lower complications, and improve recovery time.

OBJECTIVE

To describe and evaluate the safety and reproducibility of an ultrasound-guided (USG) iliopsoas tendon release using a spinal needle in a cadaveric model.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Academic Institution Procedural Skills Laboratory.

PARTICIPANTS

Five unembalmed cadaveric specimens (three female, two male), 69 to 93 years of age (mean 83.2 years), with a mean body mass index (BMI) of 24.5 kg/m² (range 19.2 to 30.3 kg/m² ).

INTERVENTIONS

Two operators each performed five USG iliopsoas tendon releases. Three additional investigators dissected the pelves to assess completeness of tendon release and damage to adjacent structures.

MAIN OUTCOME MEASURES

Successful transection, completeness (%) of the tendon transection, damage to adjacent structures, and procedural time.

RESULTS

Nine of 10 releases achieved the target release of ≥75% tendon transection. One procedure achieved 50% tendon release. No injury to adjacent structures was identified. The mean duration of the procedure was 6.19 minutes.

CONCLUSIONS

USG iliopsoas tendon release can be performed in a cadaveric model, consistently achieve the desired percentage of tendon release, does not result in injury to adjacent neurovascular structures, and takes approximately 6 minutes to perform. Although results cannot be generalized to a clinical setting, due to the minimally invasive nature of the procedure, it is likely that this procedure can be performed safely in an outpatient setting under local anesthesia, will cost less, and will facilitate a more rapid recovery when compared to standard surgical procedures. Further research is warranted for clinical application.

Mechanics of Psoas Tendon Snapping. A Virtual Population Study

Internal snapping of the psoas tendon is a frequently reported condition, especially in young adolescents involved in sports. It is defined as an increased tendon excursion over bony or soft tissue prominence causing local irritation and inflammation of the tendon leading to groin pain and often is accompanied by an audible snap. Due to the lack of detailed dynamic visualization means, the exact mechanism of the condition remains poorly understood and different theories have been postulated related to the etiology and its location about the hip. In the present study we simulated psoas tendon behavior in a virtual population of 40,000 anatomies and compared tendon movement during combined abduction, flexion and external rotation and back to neutral extension and adduction. At risk phenotyopes for tendon snapping were defined as the morphologies presenting with excess tendon movement. There were little differences in tendon movement between the male and female models. In both populations, abnormal tendon excursion correlated with changes in mainly the femoral anatomy (male r = 0.72, p < 0.001, female r = 0.66, p < 0.001): increased anteversion and valgus as well as a decreasing femoral offset and ischiofemoral distance. The observed combination of shape components correlating with excess tendon movement in essence presented with a medial positioning of the minor trochanter. This finding suggest that psoas snapping and ischiofemoral impingement are possibly two presentations of a similar underlying rotational dysplasia of the femur.

Imaging Methods for Ultrasound Contrast Agents

Microbubble contrast agents were introduced more than 25 years ago with the objective of enhancing blood echoes and enabling diagnostic ultrasound to image the microcirculation. Cardiology and oncology waited anxiously for the fulfillment of that objective with one clinical application each: myocardial perfusion, tumor perfusion and angiogenesis imaging. What was necessary though at first was the scientific understanding of microbubble behavior in vivo and the development of imaging technology to deliver the original objective. And indeed, for more than 25 years bubble science and imaging technology have evolved methodically to deliver contrast-enhanced ultrasound. Realization of the basic bubbles properties, non-linear response and ultrasound-induced destruction, has led to a plethora of methods; algorithms and techniques for contrast-enhanced ultrasound (CEUS) and imaging modes such as harmonic imaging, harmonic power Doppler, pulse inversion, amplitude modulation, maximum intensity projection and many others were invented, developed and validated. Today, CEUS is used everywhere in the world with clinical indications both in cardiology and in radiology, and it continues to mature and evolve and has become a basic clinical tool that transforms diagnostic ultrasound into a functional imaging modality. In this review article, we present and explain in detail bubble imaging methods and associated artifacts, perfusion quantification approaches, and implementation considerations and regulatory aspects.

Iliopsoas snapping hip: improving the diagnostic value of magnetic resonance imaging with a novel parameter

OBJECTIVE

To illustrate an advanced imaging parameter that describes the course of the iliopsoas tendon, and evaluate its correlations with iliopsoas internal hip snapping syndrome.

METHODS

This retrospective cohort study reviewed hip MRI images of all patients seen by a single surgeon between January 2015 and March 2016. The comparison group included all patients with clinical internal hip snapping, versus the control group that did not. MRI images were processed using minimum intensity projection. Measurements obtained of the pelvis and course of the iliopsoas tendon included: pelvic incidence, coronal angle, and sagittal opening angle (SOA). Comparison of measurements between the groups was performed with Mann-Whitney U analysis and receiver operator curve (ROC) plotting, with a significance cutoff of p = 0.05.

RESULTS

The control group (n = 85) and comparison group (n = 48) demonstrated no difference in age or gender. Pelvic incidence was similar [51.3 (± 10.7) degrees control versus 52.2 (± 7.7) degrees comparison (p = 0.36)], as was coronal angle [13.9 (± 4.6) degrees control versus 14.8 (±4.8) degrees comparison (p = 0.15)]. There was a significant difference in SOA [137.0 (± 5.9) degrees control versus 141.9 (± 6.5) degrees comparison (p < 0.01)]. ROC analysis revealed SOA threshold of 140 degrees for clinical IP hip snapping (p < 0.01), with odds ratio 5.2 (2.4-11.3) for SOA > 140 degrees.

CONCLUSIONS

Iliopsoas hip snapping is often part of a more complex disease process. While challenging to diagnose, advanced imaging parameters, like the sagittal opening angle, relate with clinical pathology. The SOA offers diagnostic value, with a threshold of greater than 140 degrees significantly correlating with clinical presentation.

US Assessment of Sports-related Hip Injuries

Traumatic and overuse hip injuries occur frequently in amateur and professional athletes. After clinical assessment, imaging plays an important role in diagnosis and in defining care management of these injuries. Ultrasonography (US) is being increasingly used in assessment of hip injuries because of the wide availability of US machines, the lower cost, and the unique real-time imaging capability, which allows both static and dynamic evaluation as well as guidance of point-of-care interventions such as fluid aspiration and steroid injection. Accurate diagnosis of hip injuries is often challenging, given the complex soft-tissue anatomy of the hip and the wide spectrum of injuries that can occur. To conduct a skillful US evaluation of hip injuries, physicians must have pertinent knowledge of the normal anatomy and should make judicious use of surface anatomy landmarks while using a compartmentalized diagnostic approach. In this article, common sports-related injuries of the anterior, lateral, and posterior hip compartments are discussed. This review includes assessment of joint effusion, acetabular labral tear, acute and chronic tendon injuries including tendinopathy, partial and full-thickness tears, snapping hip syndromes, relevant US-guided procedures, and some other conditions such as Morel-Lavallée lesion and perineal nodular induration. Principles of care management and current knowledge on imaging findings that may affect return to activity are also presented. Using an oriented US examination technique and having knowledge of the normal hip anatomy will help physicians characterize US findings of common sports-related hip injuries and make accurate diagnoses. Online supplemental material is available for this article. ^©RSNA, 2018.

Musculoskeletal ultrasound: athletic injuries of the lower extremity

Athletic injuries of the lower extremities are commonly encountered in clinical practice. While some pathology can be diagnosed on physical exam, others are a clinical dilemma with nonspecific symptomatology. In these situations, ultrasound imaging can be utilized as an exceptional diagnostic tool, offering unique advantages over other imaging modalities. This article will review the imaging characteristics of commonly encountered athletic injuries of the lower extremity.

[Arthroscopic treatment of psoas impingement]

OBJECTIVE

Tenotomy of the psoas tendon in symptomatic internal coxa saltans or psoas impingement should relieve pain.

INDICATIONS

Indicated in conservative treatment-resistant internal coxa saltans and in psoas impingement.

CONTRAINDICATIONS

Contraindications are symptomatic psoas pathologies in hip dysplasia patients.

SURGICAL TECHNIQUE

Three different procedures exist with the arthroscopic technique, in which the psoas tenotomy can be performed at one of three different levels. These are the arthroscopic transcapsular, the endoscopic extra-articular, and the arthroscopic central techniques.

POSTOPERATIVE MANAGEMENT

Forearm crutches are recommended for approximately 2-4 weeks as well as physiotherapy to strengthen the hip flexors.

RESULTS

A literature-based comparison could reveal no difference between the extra-articular and transcapsular techniques. Particularly in the long term was no loss of strength evident. Various different authors describe the techniques as good, finding neither complications nor recurrence of internal snapping hip.

Sports Injuries about the Hip: What the Radiologist Should Know

Injuries of the hip and surrounding structures represent a complex and commonly encountered scenario in athletes, with improper diagnosis serving as a cause of delayed return to play or progression to a more serious injury. As such, radiologists play an essential role in guiding management of athletic injuries. Familiarity with hip anatomy and the advantages and limitations of various imaging modalities is of paramount importance for accurate and timely diagnosis. Magnetic resonance (MR) imaging is often the modality of choice for evaluating many of the injuries discussed, although preliminary evaluation with conventional radiography and use of other imaging modalities such as ultrasonography (US), computed tomography, and bone scintigraphy may be supplementary or preferred in certain situations. Stress fractures, thigh splints, and posterior hip dislocations are important structural injuries to consider in the athlete, initially imaged with radiographs and often best diagnosed with MR imaging. Apophyseal injuries are particularly important to consider in young athletes and may be acute or related to chronic repetitive microtrauma. Femoroacetabular impingement has been implicated in development of labral tears and cartilage abnormalities. Tear of the ligamentum teres is now recognized as a potential cause of hip pain and instability, best evaluated with MR arthrography. Greater trochanteric pain syndrome encompasses a group of conditions leading to lateral hip pain, with US playing an increasingly important role for both evaluation and image-guided treatment. Muscle injuries and athletic pubalgia are common in athletes. Lastly, snapping hip syndrome and Morel-Lavallée lesions are two less common but nonetheless important considerations. ^©RSNA, 2016.

Pediatric musculoskeletal ultrasound

The expanding applications of musculoskeletal ultrasound include many examinations that are new to pediatric radiologists but are well known to our adult colleagues. In this review we present an introduction and guide to some of these entities for pediatric radiologists making inroads into the world of musculoskeletal ultrasound.

Imaging of impingement syndromes around the hip joint

Impingement syndromes are increasingly recognised as significant causes of hip pain and dysfunction. A broad spectrum of intraarticular and extraarticular conditions has been implicated in their pathophysiology. Physical examination is often inconclusive as clinical findings may be unclear or misleading, often simulating other disorders. With current improvements in imaging techniques and better understanding of hip impingement related pathomechanisms, these entities can be accurately diagnosed. In addition, preoperative imaging has allowed for targeted treatment planning. This article provides an overview of the various types of hip impingement, including femoroacetabular impingement, ischiofemoral impingement, snapping hip syndrome, greater trochanteric-pelvic and subspine impingement. Current literature data regarding their pathogenesis, clinical manifestation and imaging work-up are discussed.

Magnetic Resonance Imaging of Nonneoplastic Musculoskeletal Pathologies in the Pelvis

Musculoskeletal pathologies in the pelvis encompass a wide variety of lesions including femoroacetabular impingement, athletic pubalgia, ischiofemoral impingement, and apophyseal avulsion injuries. Magnetic resonance imaging is the noninvasive imaging modality of choice for the diagnosis and management of these lesions. In this article, the authors discuss the nonneoplastic musculoskeletal lesions in the pelvis, with illustrations and relevant case examples.

Indications for Hip Arthroscopy

CONTEXT

Hip arthroscopy is gaining popularity within the field of orthopaedic surgery. The development and innovation of hip-specific arthroscopic instrumentation and improved techniques has resulted in improved access to the hip joint and ability to treat various hip pathologies.

EVIDENCE ACQUISITION

Electronic databases, including PubMed and MEDLINE, were queried for articles relating to hip arthroscopy indications (1930-2017).

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Initially used as a technique for loose body removal, drainage/debridement of septic arthritis, and treatment of pediatric hip disorders, hip arthroscopy is currently used to treat various hip conditions. The recognition of femoroacetabular impingement (FAI) as a source of hip pain in young adults has rapidly expanded hip arthroscopy by applying the principles of osseous correction that were previously described and demonstrated via an open surgical dislocation approach. Hip pathologies can be divided into central compartment, peripheral compartment, peritrochanteric space, and subgluteal space disorders.

CONCLUSION

Although hip arthroscopy is a minimally invasive procedure that may offer decreased morbidity, diminished risk of neurovascular injury, and shorter recovery periods compared with traditional open exposures to the hip, it is important to understand the appropriate patient selection and indications.

Hip Imaging in Athletes: Sports Imaging Series

Hip or groin pain in athletes is common and clinical presentation is often nonspecific. Imaging is a very important diagnostic step in the work-up of athletes with hip pain. This review article provides an overview on hip biomechanics and discusses strategies for hip imaging modalities such as radiography, ultrasonography, computed tomography, and magnetic resonance (MR) imaging (MR arthrography and traction MR arthrography). The authors explain current concepts of femoroacetabular impingement and the problem of high prevalence of cam- and pincer-type morphology in asymptomatic persons. With the main focus on MR imaging, the authors present abnormalities of the hip joint and the surrounding soft tissues that can occur in athletes: intraarticular and extraarticular hip impingement syndromes, labral and cartilage disease, microinstability of the hip, myotendinous injuries, and athletic pubalgia. (©) RSNA, 2016.

The iliotibial tract: imaging, anatomy, injuries, and other pathology

The iliotibial tract, also known as Maissiat's band or the iliotibial band, and its associated muscles function to extend, abduct, and laterally rotate the hip, as well as aid in the stabilization of the knee. A select group of associated injuries and pathologies of the iliotibial tract are seen as sequela of repetitive stress and direct trauma. This article intends to educate the radiologist, orthopedist, and other clinicians about iliotibial tract anatomy and function and the clinical presentation, pathophysiology, and imaging findings of associated pathologies. Specifically, this article will review proximal iliotibial band syndrome, Morel-Lavallée lesions, external snapping hip syndrome, iliotibial band syndrome and bursitis, traumatic tears, iliotibial insertional tendinosis and peritendonitis, avulsion fractures at Gerdy's tubercle, and Segond fractures. The clinical management of these pathologies will also be discussed in brief.

Imaging of the hip: a systematic approach to the young adult hip

BACKGROUND

Great advances in knowledge and understanding of the biomechanics of the hip, both in arthroscopic procedures and imaging techniques, have expanded and improved the diagnosis of pathologies of the young adult hip. The anatomy of the hip joint is complex due to its morphology and orientation. The inter-pretation of the images requires deep knowledge of the osseous and soft tissue anatomy: muscles, tendons, ligaments, vessels and nerves. There are multiple imaging tools. Diagnostic techniques have different utilities and often are complementary.

METHODS

In this article the various diagnostic imaging techniques for evaluation of hip pathologies are discussed, their indications and usefulness, with emphasis on those resolved arthroscopically.

CONCLUSION

Young adult hip disorders are increasingly diagnosed and treated as arthroscopic procedures improved. Radiology is a fundamental contribution in the diagnostic process. Plain radiography (X-ray) is always the initial examination.

LEVEL OF EVIDENCE

V.

Internal snapping hip syndrome in dynamic ultrasonography

Snapping hip syndrome is an audible or palpable snap in a hip joint during movement which may be accompanied by pain or locking. It is typically seen in young athletes performing activities requiring repeated extreme movements of the hip. It may also follow a physical trauma, intramuscular injections or surgeries. There are two main forms of snapping hip: extra- or intra-articular. Extra-articular snapping hip is elicited by an abnormal movement of specific tendons and is divided into two forms: internal and external. The internal form of snapping hip syndrome is attributed to an abrupt movement of an iliopsoas tendon against an iliopectineal eminence. Radiograph results in patients with this form of snapping tend to be normal. Dynamic ultrasound is the gold standard diagnostic technique in both forms of extra-articular snapping hip syndrome. The objective of the following text is to describe a step-by-step dynamic ultrasonography examination in internal extra-articular snapping hip syndrome in accordance to the proposed checklist protocol. To evaluate abrupt movement of an involved tendon, the patient needs to perform specific provocation tests during the examination. With its real-time imaging capabilities, dynamic ultrasonography detects the exact mechanism of the abnormal tendon friction during hip movement in a noninvasive way. It also allows for a diagnosis of additional hip tissue changes which may be causing the pain.

Core Injuries Remote from the Pubic Symphysis

The core, or central musculoskeletal system of the torso, is essential for participating in sports and other physical activities. Core injuries are commonly encountered in athletes and active individuals. The importance of the midline pubic plate and rectus abdominis-adductor aponeurosis for core stability and function is discussed in the literature. This review article examines other important core injuries remote from the pubic symphysis, relevant clinical features, and preferred approaches to imaging. Several specific syndromes encountered in the core are reviewed. By protocoling imaging studies and identifying pathology, radiologists can add value to the clinical decision-making process and help guide therapeutic options.

Understanding and Treating the Snapping Hip

Snapping hip, or coxa saltans is a palpable or auditory snapping with movement of the hip joint. Extra-articular snapping is divided into external and internal types, and is caused laterally by the iliotibial band and anteriorly by the iliopsoas tendon. Snapping of the iliopsoas usually requires contraction of the hip flexors and may be difficult to distinguish from intra-articular coxa saltans. Ultrasound can be a useful modality to dynamically detect tendon translation during hip movement to support the diagnosis of extra-articular snapping. Coxa saltans is typically treated with conservative measures including anti-inflammatories, stretching, and avoidance of inciting activities. Recalcitrant cases are treated with surgery to lengthen the iliopsoas or the iliotibial band.

Endoscopic release of internal snapping hip: a review of literature

BACKGROUND

Internal snapping hip is a common clinical condition, characterized by an audible or palpable snap of the medial compartment of the hip. In most cases it is asymptomatic, while in a few patients, mostly in athletes who participate in activities requiring extremes of hip range of motion, the snap may become painful (internal snapping hip syndrome - ISHS).

MATERIALS AND METHODS

This is a review of current literature, focused on the pathogenesis, diagnosis and treatment of ISHS.

CONCLUSION

The pathogenesis of ISHS is multifactorial, and it is traditionally believed to be caused by the tendon snapping over the anterior femoral head or the iliopectineal ridge. Most cases of ISHS resolve with conservative treatment, which includes avoidance of aggravating activities, stretching, and NSAIDs. In recalcitrant cases, surgery may be indicated. Better results have been reported with endoscopic iliopsoas tendon release compared with open techniques, which may be related to the treatment of concomitant intra-articular pathologies. Furthermore, endoscopic treatment showed fewer complications, decreased failure rate and postop erative pain. It is important to remember that in most cases, a multiple iliopsoas tendon may exist, and that the incomplete release of the iliopsoas tendon can be a reason for refractory pain and poor results. Then, even if of not clinical relevance at long term follow-up, patients should be told about the inevitable loss of flexion strength after iliopsoas tenotomy.

LEVEL OF EVIDENCE

II.

US for diagnosis of musculoskeletal conditions in the young athlete: emphasis on dynamic assessment

Ultrasonography (US) is increasingly recognized as an important tool for diagnosis and therapeutic management of a variety of musculoskeletal conditions. Advantages of US use in the young athlete include the ability to diagnose dynamic conditions that are occult with other modalities, provide additional diagnostic information, and aid in treatment. Uses of US in young patients include evaluation of acquired musculoskeletal conditions that manifest with symptoms and assessment of congenital variants that may manifest with pain or limitations in activity. Acquired conditions in the young athlete include tendon disorders, such as proximal tendinosis, and ligament disorders, such as anterior talofibular ligament or ulnar collateral ligament tears. While static images are frequently able to depict these disorders without difficulty, a dynamic examination that provides stress to the joint of interest may be able to uncover a ligament tear or insufficiency and concurrently provide the clinician with information regarding joint stability. Numerous congenital variants that occur throughout the musculoskeletal system can be associated with awkward sensations such as snapping, popping, and clunking and occasionally with pain. Pathologic processes associated with congenital variants in the upper extremities include slipping rib syndrome, atraumatic anterior subluxation of the sternoclavicular joint, and snapping triceps syndrome. Conditions that affect the lower extremities include internal and external snapping hip syndrome, snapping knee syndrome, and medial plica syndrome. The dynamic capability of US is ideal for diagnosis of many conditions that affect the musculoskeletal system of the young athlete, many of which would be difficult or impossible to identify with use of other imaging modalities.

Internal Snapping Hip Syndrome: Incidence of Multiple-Tendon Existence and Outcome After Endoscopic Transcapsular Release

PURPOSE

To report the frequency of presentation of bifid or multiple iliopsoas tendons in patients who underwent endoscopic release for internal snapping hip syndrome (ISHS) and to compare both groups.

METHODS

A consecutive series of patients with ISHS were treated with endoscopic transcapsular release of the iliopsoas tendon at the central compartment and prospectively followed up. The inclusion criteria were patients with a diagnosis of ISHS with failure of conservative treatment. During the procedure, the presence of a bifid tendon was intentionally looked for. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were evaluated preoperatively and at last follow-up. Four patients presented with a bifid tendon and one patient had 3 tendons. At a minimum of 12 months' follow-up, the presence of snapping recurrence was evaluated and the WOMAC scores were compared between both groups.

RESULTS

Among 279 hip arthroscopies, 28 patients underwent central transcapsular iliopsoas tendon release. The mean age was 29.25 years (range, 16 to 65 years; 6 left and 22 right hips). Group 1 included 5 patients with multiple tendons; the remaining patients formed group 2 (n = 23). None of the patients presented with ISHS recurrence. The mean WOMAC score in group 1 was 39 points (95% confidence interval [CI], 26.2 to 55.4 points) preoperatively and 73.6 points (95% CI, 68.4 to 79.6 points) at last follow-up. In group 2 the mean WOMAC score was 47.21 points (95% CI, 44.4 to 58.2 points) preoperatively and 77.91 points (95% CI, 67.8 to 83.4 points) at last follow-up. We identified a bifid tendon retrospectively on magnetic resonance arthrograms in 3 of the 5 cases that were found to have multiple tendons during surgery. None of these were recognized before the procedures.

CONCLUSIONS

In this series the surgeon intentionally looked for multiple tendons, which were found in 17.85% of the cases. Clinical results in patients with single- and multiple-tendon snapping seem to be similarly adequate. However, the possibility of a type II error should be considered given the small number of patients.

LEVEL OF EVIDENCE

Level IV.

Hip Pain in Athletes - When It is Not the Labrum

Hip pain is a relatively common complaint in sports. It is tempting to blame the athlete's symptoms on labral pathology. However, there is a high incidence of asymptomatic labral disease. Therefore, even when a labral tear is present, it may not be the underlying cause of the patient's pain. Clinicians should familiarize themselves with the large differential diagnosis for hip and pelvis pain to include nonmusculoskeletal pathology. This article reviews nonlabral causes of hip pain in athletes. For ease of classification, the hip is divided into anterior, lateral, and posterior regions.

Painful snapping hip owing to bifid iliopsoas tendon and concurrent labral tear

A case of internal snapping hip owing to a bifid iliopsoas tendon is described with a concurrent labral tear in a young active female. The labral tear was identified on magnetic resonance imaging, and the snapping bifid tendon on dynamic ultrasound. The patient was administered bupivicaine and steroid around the tendon and symptoms resolved. A snapping bifid tendon must be identified pre-operatively to avoid incomplete release. Labral repair may be accompanied by psoas release when psoas impingement is suspected owing to a labral tear at the 3 o’clock position in an otherwise normal hip.

Optimal Elbow Angle for Sonographic Visualization of the Ulnar Collateral Ligament

OBJECTIVE

To formally examine the sonographic appearance of the elbow ulnar collateral ligament (UCL) at 30° versus 70° of elbow flexion in asymptomatic baseball pitchers.

DESIGN

A prospective, cross-sectional design.

SETTING

Sports medicine clinic in a tertiary academic medical center.

PARTICIPANTS

Thirty asymptomatic adolescent baseball pitchers 13-18 years of age (mean 15.8 years), with at least 3 years of continuous pitching experience and no significant history of elbow pain or injury.

METHODS

Static sonographic images of the bilateral UCLs were obtained at 30° and 70° of elbow flexion by a single experienced examiner. Images were anonymized and randomized into a slide set. Three clinicians with different levels of ultrasound experience reviewed the static 30° and 70° images for each elbow and chose their preferred image based on UCL conspicuity. The clinicians reviewed a re-randomized slide set 1 week later. A different study co-investigator measured UCL cross-sectional area (CSA) on all images using ultrasound machine electronic calipers.

MAIN OUTCOME MEASURES

Preference for the sonographic conspicuity of the UCL at 30° versus 70° of elbow flexion, and UCL CSA at 30° versus 70° of flexion.

RESULTS

Each clinician demonstrated a significant preference for UCL images obtained at 70° of flexion when compared to those obtained at 30° (80.3% overall preference for 70°, P < .001). There was no statistically significant effect of clinician experience or arm dominance on image preference. The sonographically determined CSA of the UCLs were on average 1.4 mm(2) greater at 70° than at 30° of flexion (P < .001) when combining dominant and nondominant arms.

CONCLUSIONS

Static sonographic evaluation of the UCL at 70° of elbow flexion should be integrated into UCL imaging protocols. Furthermore, when performing sonographically guided procedures targeting the UCL, clinicians should consider positioning the elbow at >30° of flexion to optimize UCL conspicuity and CSA.

Sonography of sports injuries of the hip

CONTEXT

Sports-related injuries of the hip are a common complaint of both competitive and recreational athletes of all ages. The anatomic and biomechanical complexity of the hip region often cause diagnostic uncertainty for the clinicians evaluating these injuries. Therefore, obtaining additional diagnostic information is often crucial for providing injured athletes with a prompt and accurate diagnosis so they can return to activity as soon as possible. Musculoskeletal ultrasound is becoming increasingly important in evaluating and treating sports-related injuries of the hip.

EVIDENCE ACQUISITION

The PubMed database was searched in May of 2013 for English-language articles pertaining to sonography of sports injuries of the hip using the following keywords in various combinations: musculoskeletal, ultrasound, hip, hip sonography, and sports.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Musculoskeletal ultrasound is currently being used for both diagnosis and treatment in a wide range of acute and chronic conditions affecting the hip, including tendinosis, tendon/muscle strains, ligamentous sprains, enthesopathies, growth plate injuries, fractures, bursitis, effusions, synovitis, labral tears, and snapping hip. Therapeutically, it is used to guide injections, aspirations, and biopsies.

CONCLUSION

Musculoskeletal ultrasound use is expanding and will likely continue to do so as more clinicians realize its capabilities. Characteristics, including accessibility, portability, noninvasiveness, dynamic examination, power Doppler examination, and low cost highlight the potential of ultrasound.