MR imaging of overuse injuries of the hip

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 Overuse Injuries of the Hip

Overuse injuries of the hip are common, and clinical diagnosis may be difficult because of overlapping and nonspecific clinical symptoms. Imaging can play an essential role in guiding diagnosis and management. Femoroacetabular joint structural abnormalities result in various conditions that can predispose patients to early development of osteoarthritis. Repetitive stress on the skeletally immature hip can result in apophyseal injuries. Notable nonosseous overuse hip pathologies include athletic pubalgia, trochanteric bursitis, and injuries involving the iliopsoas myotendinous unit. Timely diagnosis of overuse injuries of the hip can facilitate improved response to conservative measures and prevent irreversible damage.

External snapping hip: classification based on magnetic resonance imaging features and clinical correlation

BACKGROUND

With the increasing sport population, the number of patients with external snapping hip (ESH) has also increased. To detect and visualise pathological soft tissue changes, magnetic resonance imaging (MRI) has been 1 of the most useful modalities. However, only limited studies have investigated MRI and its clinical value in the treatment of ESH in the past.

MATERIALS AND METHODS

Between May 2017 and November 2018, 104 patients were diagnosed with ESH at our institution. We excluded patients who did not undergo an MRI (n = 11), had complaint of bilateral symptom (n = 17), were not diagnosed hip problems previously (n = 2), and were lost-follow-up within 6 months (n = 19). After applying the exclusion criteria, 55 patients remained. We classified the patients into 2 groups according-MRI findings: tensed iliotibial band (ITB) and hypertrophied gluteus maximus (GM). We investigated the clinical findings, such as mean age, symptom duration, pain score, grading based on symptom severity, and other radiological findings such as soft tissue signal change and ITB thickness. The variables were compared between the groups.

RESULTS

Between the 2 groups defined by MRI findings, the group characterised by tense ITB showed a relatively short symptom duration than the hypertrophied GM group (p < 0.001). No significant differences in the other variables were found between the groups.

CONCLUSIONS

ESH has 2 types of MRI features. Compared with the hypertrophied GM group, the tense ITB group showed a shorter symptom duration and a more reversible status.

A Perspective on Reversibility of Tendinosis-Induced Multi-Level Adaptations

Achilles tendinopathy is a well-known pathology that can display interindividual variations in chronicity, symptom presentation, and tendon morphology. Furthermore, symptoms may fluctuate within an individual throughout the stages of the pathology. Although pain is often used as a marker of condition severity, individuals may not consistently report pain due to periods of remission. Persons with tendinosis, which is characterized by advanced morphological alterations, have shown consistent changes in neuromechanics that indicate adaptations in the sensory-motor and the central nervous systems. The current treatment strategy involves repetitive resistance exercise aiming to achieve recovery of lost function. This treatment approach, however, has gauged such functional recovery through symptom relief and return to sport, which, in our opinion, may not suffice and may not prevent symptom recurrence or tendon rupture. In this physiologically informed perspective, we briefly review what is currently known about the consequences of Achilles tendon degeneration and examine the topic of reversing these changes. Shortcomings of contemporary treatment strategies are discussed and we therefore call for a new paradigm to focus on the whole-body level, targeting not only the tendon but also the reversal of the neuromotor control system adaptations.

Twenty-Year Systematic Review of the Hip Pathology, Risk Factors, Treatment, and Clinical Outcomes in Artistic Athletes-Dancers, Figure Skaters, and Gymnasts

OBJECTIVE

To identify (1) the predominant level of evidence of the clinical studies regarding the hip pathology, risk factors, treatment, and clinical outcomes in artistic athletes (dancers, figure skaters, and gymnasts) (2) the most commonly reported hip pathology, risk factors, treatments, and clinical outcomes in dancers, figure skaters, and gymnasts.

METHODS

To conduct this systematic review PubMed, EMBASE, and Scopus databases were searched for relevant studies and pertinent data were collected from the eligible articles. Included were studies which reported hip injuries in artistic athletes, the risk factors, treatment, and/or the clinical outcomes. We excluded case reports or irrelevant studies. No meta-analysis was performed because of study heterogeneity. The methodical index for nonrandomized studies (MINORS) criteria were used for quality control.

MAIN RESULTS

Thirty-eight studies were included in the analysis. The mean MINORS score was 13.6 ± 4.6 points indicating fair quality of evidence of the included articles. The predominant level of evidence was level IV. Chondrolabral pathology and muscle injuries were the most commonly reported pathologies. We found only 2 risk factor analysis studies; however, many studies reported risk correlation between artistic sports or imaging findings and hip pathology. Treatment strategies were reported in only 7 studies, clinical outcomes are significantly underreported.

CONCLUSION

Chondrolabral pathology was the most commonly reported hip pathology in artistic athletes, however, prospective cohort studies are necessary to really understand these injuries and their associated risk factors. The lack of clinical outcomes is significant and future data collection is required to assess the effectiveness of the various treatments.

MRI of the hip: current concepts on bone marrow oedema

Bone marrow oedema (BME) is commonly found in hip MR imaging. BME is a nonspecific finding which can be related to a wide variety of diseases. However, there are cases where its existence or its pattern can narrow the differential or even point to a specific diagnosis. Therefore, deep understanding of its pathophysiology is of utmost importance for clinicians and radiologists in order to avoid diagnostic pitfalls. We hereby present currently established knowledge on BME related to adult hip pathology, aiming to raise physicians' suspicion and to highlight that it is mandatory to combine specific imaging patterns with the history, clinical and laboratory findings in order to achieve accurate diagnosis.

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.

Snapping hip syndrome: systematic review of surgical treatment

The snapping hip (SH) syndrome is characterised by an audible snapping, often accompanied by pain, which usually occurs with the flexion and extension of the hip during exercise or ordinary daily activities.The causes of SH can be classified as external, internal and intraarticular. The prevalence of asymptomatic SH in the population is unknown and the incidence of symptomatic cases is not well-defined. The painless snapping in the hip is common in the general population; the symptomatic SH with debilitating pain and weakness is often seen in those who take part in activities such as ballet and running hurdles.The clinician's goal is to determine the cause and treat patients who have symptomatic SH so that they may return to their activities or to athletic peak performance.Most patients with SH can be treated conservatively. However, surgery may be indicated if the condition becomes chronically symptomatic. Arthroscopy may prove useful in the treatment of intraarticular lesions that are causing discomfort. Various techniques have been described with different grades of success. The aim is to achieve the least invasive procedure with the lowest potential complications that corrects the painful snapping, according to the patient's characteristics.The purpose of this systematic review is to clarify the results of the surgical treatment of SH, after the failure of the conservative treatment.

Prevalence of the acetabular sublabral sulcus at MR arthrography in patients under 17 years of age: does it exist?

PURPOSE

To retrospectively determine characteristics of contrast-filled acetabular labral clefts in patients under the age of 17 years at MR arthrography (Mra) correlated with arthroscopy, which may impact the thinking regarding the existence of a sublabral sulcus.

MATERIALS AND METHODS

After IRB approval, 41 patients under the age of 17 who had MRa were identified. The following observations of contrast-filled clefts were assessed: (1) presence/absence, (2) location, (3) depth, (4) abnormal signal within the labrum and (5) shape (linear, gaping, complex). Fisher's exact and the Wilcoxon matched-pairs signed-rank test were performed. Interreader agreement was calculated with Cohen's k.

RESULTS

Reader 1 found clefts in 41 %. Depth was less than half in 6%, more than half in 65% and full thickness in 29%. Shape was linear in 53%, gaping in 18% and complex in 29%. Signal changes occurred in 88%. Reader 2 found clefts in 29%. Depth was less than half in 17%, more than half in 58% and full thickness in 25%. Shape was linear in 50%, gaping in 42% and complex in 17%. Signal changes occurred in 50%. None of the clefts fulfilled the criteria for a sublabral sulcus at MRa and arthroscopy.

CONCLUSION

None of the clefts found in our subjects under the age of 17 years met the MRa and arthroscopy criteria for a sublabral sulcus, which supports the theory that such clefts represent labral tears.

Acute calcific tendinitis of the gluteus medius: an uncommon source for back, buttock, and thigh pain

OBJECTIVE

This study was conducted to describe the imaging features and clinical manifestations in acute calcific tendinitis (CaT) of the gluteus medius muscle (GMe).

METHODS

A retrospective analysis was conducted, aimed at six patients with acute calcific tendinitis of the gluteus medius muscle (CaT-GMe), who were seen between January 2011 and December 2012. Clinical presentations, radiologic data (radiography, CT, and MRI), and laboratory reports were all subject to review.

RESULTS

All patients presented with pain and decreased range of motion (ROM) at the hip. Two of the six patients experienced pain in the anterolateral thigh and groin, with antalgic gait (anterior group). The other four complained of low back, buttock, and posterolateral thigh pain, accompanied by difficulty in standing and antalgic gait (posterior group). Edema within the GMe or effusion surrounding the muscle was regularly identified on MRIs. Calcific deposits were conspicuous in the gluteus medius tendon attachments to the lateral (anterior group) and superoposterior (posterior group) facets of the greater trochanter on radiography, CT, or MRI. Complete resolution of symptoms was uniformly achieved in 5-10 days with conservative management.

CONCLUSIONS

Acute CaT-GMe should be considered in any patient suffering lateral hip pain (with either groin or low back pain) and ROM limitation. Images of the hip characteristically show edema of the gluteus medius and calcifications lateral or superior to the greater trochanter.

Iliopsoas tendon tear: clinical and imaging findings in 4 elderly patients

Hip pain is a common clinical presentation of elderly patients in the emergency department. We report the clinical and imaging findings in 4 elderly patients with iliopsoas tendon tears who presented at our institution between October 2009 and June 2010. In 2 patients, the imaging diagnosis was significantly delayed. This injury is uncommon, and the clinical presentation in these patients may be misleading. Magnetic resonance is the imaging modality of choice after radiographs to assess these patients, and knowledge of the complex anatomy of the iliopsoas myotendinous unit helps in making the correct diagnosis. With aging of the population, the incidence of iliopsoas tendon tear is likely to increase.

Paralabral cysts in the hip joint: findings at MR arthrography

PURPOSE

The purpose of this research was to retrospectively characterize paralabral cysts of the hip as seen at MR arthrography.

MATERIALS AND METHODS

After Institutional Review Board approval, 704 patients who had MR arthrography were identified over a 3-year period and 40 patients were identified as having a cyst or fluid collection at the hip by MR report. MR images from these 40 patients were retrospectively reviewed by three radiologists where 18 were found to have a paralabral cyst, which were characterized as follows: location, configuration, contrast filling, size of the cyst, extent, direction, and whether associated osseous changes were present. In addition, the acetabular labrum was assessed for tears and, if present, the location and pattern were characterized.

RESULTS

Paralabral cysts were located anterosuperiorly in 56%, anteriorly in 22%, posterosuperiorly in 17%, and anteroinferiorly in 6% of cases. The vast majority (94%) were multilocular and filled with intra-articular contrast medium. The average dimensions were 8 × 7 × 11 mm. The paralabral cyst demonstrated extracapsular extension in 72% of cases, with 39% located between the ilium and gluteus minimus, and 22% between the ilium and iliopsoas. Remodeling of the ilium adjacent to the cyst was observed in 50% of these cases. A labral tear was at the base of the labrum adjacent to the cyst in 78% of cases, while the tear was isolated to the body of the labrum in 22%. Tears were most commonly anterosuperior (55%) or anterior (28%) in location.

CONCLUSION

Our results show that paralabral cysts of the hip are most commonly located anterosuperiorly, are multilocular, fill with intra-articular contrast medium, have average dimensions up to 11 mm, and often extend extracapsularly between muscle and bone where they may remodel the adjacent ilium.