Imaging of the hip in patients with rheumatic disorders

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.

Ultrasound in Arthritis

Ultrasound is currently performed in everyday rheumatologic practice. It is used for early diagnosis, to monitor treatment results, and to diagnose remission. The spectrum of pathologies seen in arthritis with ultrasound includes early inflammatory features and associated complications. This article discusses the spectrum of ultrasound features of arthritides seen in rheumatoid arthritis and other connective tissue diseases in adults, such as Sjögren syndrome, lupus erythematosus, dermatomyositis, polymyositis, and juvenile idiopathic arthritis. Ultrasound findings in spondyloarthritis, osteoarthritis, and crystal-induced diseases are presented. Ultrasound-guided interventions in patients with arthritis are listed, and the advantages and disadvantages of ultrasound are discussed.

Novel imaging modalities in spondyloarthritis

Novel imaging techniques have emerged in the field of spondyloarthritis. This article will cover the role of, and the sensitivity and specificity of magnetic resonance imaging (MRI) and ultrasound in the diagnosis and monitoring of axial and peripheral SpA. It will discuss how the definition of a 'positive MRI' of the sacroiliac joints and spine is evolving. Differential diagnoses of inflammatory lesions of both the sacroiliac joints and the spine are addressed due to their importance in image interpretation. The article will also discuss the role of sonography in assessing peripheral entheses, joints, tendon sheaths, nails and soft tissues. The utility for clinical as well as an outcome measure will be discussed. We finally aim to give guidance on when and how to use these new modalities and on how to analyse and interpret the imaging findings in daily practice.

MR imaging of transient osteoporosis of the hip: an update on 155 hip joints

PURPOSE

Transient osteoporosis of the hip (TOH) presents with acute onset pain and bone marrow edema (BMe) on MR imaging. The purpose of this study is to revise the MR imaging characteristics of TOH by analyzing the data derived from 155 hip examinations. We also sought to explore the relationship between the duration of symptoms and the presence of sparing and subchondral fractures.

MATERIALS AND METHODS

MR images of 155 hips (141 TOH patients) were retrospectively evaluated for the presence of insufficiency fractures and the morphology of BMe. Sparing of the medial bone marrow of the femoral head was recorded together with demographic and clinical data. Progression to regional migratory osteoporosis (RMO) and postpartum cases were also recorded.

RESULTS

Our population consisted of 76.4% male and 23.6% female patients. RMO progression was recorded in 19.4% and 4 postpartum cases displayed bilateral disease. Sparing of the medial bone marrow was present at 87.7% of patients and disappeared as the disease progressed (P=0.005). BMe was restricted within the femoral head in 11.0%, extended to the femoral neck in 40% and to the femoral shaft in 49% of the cases studied. Subchondral fractures were present at 48.7% of the hips.

CONCLUSION

This study describes TOH patient characteristics, the MR imaging findings (BMe pattern, microfractures), their association with symptom duration and the chance of progressing to RMO.

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.

Radiographic Hip Involvement in Ankylosing Spondylitis: Factors Associated with Severe Hip Diseases

Objective.

To determine the factors associated with severe radiographic hip involvement in patients with ankylosing spondylitis (AS).

Methods.

A cross-sectional retrospective study was performed. The patients were classified into 3 groups based on the Bath Ankylosing Spondylitis Radiology Hip Index (BASRI-hip): minimal hip disease, moderate hip disease, and severe hip disease. Demographic, clinical, radiographic, and laboratory data were collected and analyzed. To identify factors associated with severe hip disease, ordinal regression analyses were performed.

Results.

A total of 256 patients were involved in the study. There were differences in the age at onset, delay in diagnosis, bilateral hip involvement, sacroiliitis, Schober’s index, and occiput-to-wall distance among the 3 groups (p < 0.05). The patients with severe hip disease had lower C-reactive protein and erythrocyte sedimentation rate levels than did the minimal group (p < 0.05). The functional status based on the Bath Ankylosing Spondylitis Functional Index and the Harris Hip Score showed significant differences (p < 0.05). The results of the ordinal regression analyses showed that bilateral hip involvement, sacroiliitis, delay in diagnosis, age at onset, and spinal involvement were associated with a higher BASRI-hip (p < 0.05).

Conclusion.

Bilateral hip involvement, severe sacroiliitis, longer delay in diagnosis, early disease onset, and spinal involvement are associated with severe hip disease in patients with AS. The severity of hip involvement is associated with the functional status in AS.

Greater trochanter pain syndrome: a descriptive MR imaging study

OBJECTIVE

Greater trochanter pain syndrome (GTPS) is a diverse clinical entity caused by a variety of underlying conditions. We sought to explore the impact of (1) hip morphology, namely the center-edge angle (CEa) and femoral neck-shaft (NSa) angle, (2) hip abductor tendon degeneration, (3) the dimensions of peritrochanteric edema and (4) bursitis, on the presence of GTPS, using MR imaging.

MATERIALS AND METHODS

The presence of pain was prospectively assessed blindly by the senior author. CEa and NSa were blindly measured in 174 hip MR examinations, after completion of the clinical evaluation by another evaluator. The existence and dimensions of T2 hyperintensity of the peritrochanteric soft tissues, the existence and dimensions of bursae, as well as degeneration and tearing of gluteus tendons were also recorded.

RESULTS

Out of 174 examinations, 91 displayed peritrochanteric edema (group A) and 34 bursitis, all with peritrochanteric edema (group B). A number of 78 patients from both A and B groups, showed gluteus medius tendon degeneration and one tendon tear. CEa of groups A and B were 6° higher than those of normals (group C, P=0.0038). The mean age of normals was 16.6 years less than in group A and 19.8 years less than in group B (P<0.0001). Bursitis was associated with pain with a negative predictive value of 97% (P=0.0003).

CONCLUSION

Acetabular morphology is associated with GTPS and the absence of bursitis was proved to be clinically relevant. Peritrochanteric edema alone was not associated with local pain.

Evaluation of the novel ultrasound score for large joints in psoriatic arthritis and ankylosing spondylitis: six month experience in daily clinical practice

Background

To evaluate the utility of the recently introduced SOLAR score (sonography of large joints in Rheumatology), which has been validated in RA patients, in a cohort of patients with Psoriatic Arthritis (PsA) and Ankylosing Spondylitis (AS) presenting with involvement of large peripheral joints.

Methods

The recently established SOLAR score has been designed to determine the degree of inflammation in the shoulder, the elbow, the hip and the knee joint in patients suffering from RA. Since large joints are frequently involved in PsA and AS, synovitis and synovial vascularity were scored semiquantitatively (grade 0–3) by grey scale (GSUS) and power Doppler ultrasound (PDUS) utilizing the validated scoring system. Each joint was scanned from different angles, the knee joint for example was divided into four areas to score for synovitis: the suprapatellar longitudinal, the medial longitudinal, the lateral longitudinal, and the posterior region. Each area was scored from 0–3, so a maximum score of 12 could be achieved. PsA and AS patients presenting with peripheral joint disease involving large joints were examined at baseline, 3 and 6 months after initiation of local or systemic therapy (DMARDs/Biologics). For evaluation of the inflammatory status, the erythrocyte sedimentation rate (ESR) was determined.

Results

A cohort of 126 patients were enclosed, and 83 of these were followed for 6 months. At baseline before modification of the therapy, patients received DMARDs (n = 83), DMARDs plus biologics (n = 30), or biologic monotherapy (n = 29). Following intervention, all US scores demonstrated a marked improvement. The GSUS and the PDUS scores for all joint areas, except the PDUS score of the hip, exhibited a significant improvement (p < 0.05), while the GSUS of the knee showed even a highly significant (p < 0.001) change. The ESR displayed a significant decrease from 27 to 19 mm (p < 0.002) representing good treatment response.

Conclusion

The SOLAR score, which has been recently introduced for RA patients, is a very suitable instrument for the qualitative and quantitative evaluation of large joint involvement in PsA and AS patients and allows for treatment monitoring.

Prevalence study of iliopsoas bursitis in a cohort of 860 patients affected by symptomatic hip osteoarthritis

We used ultrasound to evaluate iliopsoas bursitis (IB) prevalence in 860 patients (568 males, 292 females, 62 ± 7 years) suffering from symptomatic Kellgren-Lawrence grade II-III-IV hip osteoarthritis. Lequesne index and visual analogue scale (VAS) were recorded. Anterior hip was scanned and images recorded. Maximum IB diameter was measured and drained (volume recorded). Two radiologists evaluated the presence of IB, joint effusion, synovial hypertrophy, communication between bursa and articular space. IB was found in 19/860 (2.2%) patients (16 males, 3 females, 65 ± 11 years; grade II osteoarthritis = 4; III = 9; IV = 6). Mean bursa diameter = 2.9 ± 0.9 cm, volume = 35 ± 34 mL. Effusion was present in 9/19 patients, hypertrophy in 6/19 and communication in 9/19. In patients with no IB, effusion was detected in 27/860 and hypertrophy in 25/860 (p < 0.001 compared with IB patients). κ = 1 for all. VAS index and Lequesne index were not significantly different between patients with or without IB (p ≥ 0.468). Ultrasound can detect associate findings in grade II-IV hip osteoarthritis patients with high reproducibility.