Age-dependent arthrosonographic reference values of the hip joint in healthy children and adolescents - a cross-sectional multicenter ultrasound study

Ultrasound-guided determination demonstrates influence of age, sex and type of sport on medial femoral condyle cartilage thickness in children and adolescents

PURPOSE

To analyse the reliability of ultrasound-guided measurement of the cartilage thickness at the medial femoral condyle in athletically active children and adolescents before and after mechanical load in relation to age, sex and type of sport.

METHODS

Three successive measurements were performed in 157 participants (median/min-max age: 13.1/6.0-18.0 years, 106 males) before and after mechanical load by squats at the same site of the medial femoral condyle by defined transducer positioning. Test-retest reliability was examined using Cronbach'sα $\alpha $ calculation. Differences in cartilage thickness were analysed with respect to age, sex and type of practiced sports, respectively.

RESULTS

Excellent reliability was achieved both before and after mechanical load by 30 squats with a median cartilage thickness of 1.9 mm (range: 0.5-4.8 mm) before and 1.9 mm (0.4-4.6 mm) after mechanical load. Male cartilages were thicker (p < 0.01) before (median: 2.0 mm) and after (2.0 mm) load when compared to female cartilage (before: 1.6 mm; after: 1.7 mm). Median cartilage thickness was about three times higher in karate athletes (before: 2.3 mm; after: 2.4 mm) than in sports shooters (0.7; 0.7 mm). Cartilage thickness in track and field athletes, handball players and soccer players were found to lay in-between. Sport type related thickness changes after mechanical load were not significant.

CONCLUSION

Medial femoral condyle cartilage thickness in childhood correlates with age, sex and practiced type of sports. Ultrasound is a reliable and simple, pain-free approach to evaluate the cartilage thickness in children and adolescents.

LEVEL OF EVIDENCE

Level III.

Structural ultrasound of joints and tendons in healthy children: development of normative data

BACKGROUND

Musculoskeletal ultrasound is a well accessible technique to assess disease activity in children with juvenile idiopathic arthritis. Knowledge of reference values of joint structures is indispensable to differentiate between physiological and pathological finding. The aim of this study was to assess the structural sonographic features of joints and tendons in healthy children from several age groups (0.2-18 year), and develop a set of normative data.

METHODS

Greyscale ultrasound was performed in 500 healthy children (age 0.2-18 years) according to a predefined scanning protocol (Additional file 1) including the shoulder, elbow, wrist, second metacarpophalangeal joint, hip, knee, ankle, and first metatarsophalangeal joint). Demographic data and values of cartilage thickness, tendon diameters, and the degree of capsular distention measured by bone-capsular distance (BCD) were collected. Differences according to the sex were assessed by unpaired t-test. Single and multiple regression analyses were performed between the ultrasound outcomes and covariates such as age, height, weight and body mass index. Growth charts and tables were developed with respect to age. Nonparametric quantile regression was applied using the R-packages quantreg and quantregGrowth.

RESULTS

A total of 195 male and 305 female volunteers were included between the age of 0 and 18 years (mean age 8.9; range: 0.2-17.9 years). Cartilage diminished markedly as children aged, and cartilage of the boys was significantly thicker compared to the girls in all joints (p < 0.001). In addition, cartilage became thinner as children's height and weight increased (beta regression coefficients between - 0.27 and - 0.01, p < 0.0001). Capsular distention (i.e., BCD > 0 mm) was uncommon in the ankle, wrist and MCP2 (resp. in 3, 6, and 3% of cases). It was more common in the suprapatellar and parapatellar knee, MTP1 and posterior recess of the elbow (resp. in 34, 32, 46, and 39% of cases). In the hip, some capsular distention was always present. Age was found to be the best predictor for BCD (beta regression coefficients between 0.05 and 0.13, p < 0.0001). Height was, in addition to age, a good predictor of tendon diameter (beta regression coefficients between 0.03 and 0.14, p < 0.0001). Growth curves and tables for each variable were developed.

CONCLUSIONS

Reference values of sonographic cartilage thickness, BCD and diameters of tendons at several joints were established from 500 healthy children, aged between 0.2 and 18 years. Growth charts and tables were developed to distinguish normal findings from pathology in children with complaints suspicious of arthritis.

Contribution of Ultrasound in Current Practice for Managing Juvenile Idiopathic Arthritis

The interest and application of musculoskeletal ultrasound (MSUS) in juvenile idiopathic arthritis (JIA) are increasing. Numerous studies have shown that MSUS is more sensitive than clinical examination for detecting subclinical synovitis. MSUS is a well-accepted tool, easily accessible and non-irradiating. Therefore, it is a useful technique throughout JIA management. In the diagnostic work-up, MSUS allows for better characterizing the inflammatory involvement. It helps to define the disease extension, improving the classification of patients into JIA subtypes. Moreover, it is an essential tool for guiding intra-articular and peritendinous procedures. Finally, during the follow-up, in detecting subclinical disease activity, MSUS can be helpful in therapeutic decision-making. Because of several peculiarities related to the growing skeleton, the MSUS standards defined for adults do not apply to children. During the last decade, many teams have made large efforts to define normal and pathological US features in children in different age groups, which should be considered during the US examination. This review describes the specificities of MSUS in children, its applications in clinical practice, and its integration into the new JIA treat-to-target therapeutic approach.

Procedures for the content, conduct and format of EULAR/PReS paediatric musculoskeletal ultrasound courses

Background

Despite the worldwide increasing request of education on paediatric musculoskeletal ultrasound (PedMSUS), content, conduct and format of PedMSUS courses have never been internationally agreed.

Objectives

To produce educational procedures for the conduct, content and format of EULAR/PReS PedMSUS courses.

Methods

After a systemic literature review and expert opinion collection, a panel of items for the development of procedures on PedMSUS courses was identified. Agreement on the items was assessed through Delphi surveys among a taskforce of 24 members, which included 18 experts in PedMSUS (8 rheumatologists, 1 radiologist, 9 paediatric rheumatologists), 1 methodologist and rheumatologist expert in MSUS, 2 patient research partners, 1 health professional in rheumatology and 2 EMEUNET/EMERGE members, from 8 different European countries. Each item was assessed through a 5-point Likert scale (0, full disagreement; 5, full agreement); agreement was reached for >75% of answers rating 4–5. All items with agreement were included in the preliminary core set of educational procedures, which underwent external assessment by a broader Consensus group (Faculty and Tutors of previous EULAR PedMSUS courses and PReS Imaging Working Party members), through Delphi survey.

Results

Two Delphi surveys produced the preliminary core set of procedures for basic, intermediate, advanced and teach-the-teachers (TTT) PedMSUS courses. A Delphi survey within the Consensus group produced agreement on the proposed procedures.

Conclusions

Shared EULAR/PReS procedures for the conduct, content and format of basic, intermediate, advanced and TTT PedMSUS courses were identified on international basis.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Ultraschalldiagnostik in der Kinderrheumatologie

Der Artikel gibt einen Überblick zum aktuellen Stand der Ultraschallbefundung in der Kinderrheumatologie und geht insbesondere auf den praktischen Einsatz und die technischen Aspekte der Gelenksonografie ein. Dabei werden auch die wissenschaftlichen Entwicklungen der letzten Jahre zusammengefasst und berücksichtigt. Neben der Gelenksonografie wird die Ultraschalltechnik in der Kinderrheumatologie zunehmend auch auf weitere Körperregionen und -organe ausgeweitet, die für die kinderrheumatologische Diagnostik relevant sind.

Ultrasonography in Pediatric Rheumatology

This review highlights the increasing evidence from the last few years supporting the use of musculoskeletal ultrasonography (MSUS) in the evaluation and management of patients with pediatric rheumatic diseases, particularly focusing on juvenile idiopathic arthritis. Recently developed definitions for the sonographic appearance of healthy and pathologic joints in children are discussed. Further topics explored include how MSUS enhances the diagnosis of inflammatory joint disease (synovitis, enthesitis, tenosynovitis), including the detection of subclinical synovitis. There is a brief summary on the use of ultrasonography in the evaluations of myositis, Sjögren syndrome, and scleroderma.

The new role of musculoskeletal ultrasound in the treat-to-target management of juvenile idiopathic arthritis

This article reviews the role of musculoskeletal ultrasound (MSUS) for the diagnosis, monitoring and treat-to-target management of JIA. Technological advancements in MSUS allow more precise evaluation of arthritis, tenosynovitis and enthesitis versus clinical examination alone, which may assist treatment decisions. In adult studies, serum and synovial biomarkers have correlated with MSUS findings. Within paediatric rheumatology, significant developments in the definition of normal and pathology, a necessity for the future integration of MSUS into treat-to-target management, have already been reached or are underway, which in turn could allow tighter control of disease activity and earlier identification of treatment response and failure, bringing the goal of 'precision medicine' closer. Additionally, the utility of MSUS for the evaluation of subclinical disease remains an unexamined area of interest. 'Ultrasound remission' combined with clinical assessment and immunological markers could therefore potentially improve the treat-to-target management of JIA.

Age, gender, height and weight in relation to joint cartilage thickness among school-aged children from ultrasonographic measurement

BACKGROUND

Among school-age children, the decrease of cartilage thickness (Cth) with increasing age is well known. However, the influence of body mass index (BMI), height or weight on Cth has not been revealed. Here in, we aim to establish an age- and gender-specific Cth standard reference among Asians and investigate the possible prestige of BMI, height and weight.

METHODS

A cross-sectional study was performed in healthy Asian children. Bilateral knees, ankles, wrists, second metacarpophalangeals (MCPs) and proximal interphalangeals (PIPs) were measured using ultrasound. The children's height, weight and BMI were also recorded for later adjustment.

RESULTS

A total of 200 school age Asian children (including 86 girls and 114 boys, aged between 5 to 13 years-old) were investigated. Cth differences were observed in the knees, ankles, wrists, MCPs and PIPs between sexes (p < 0.05), with girls having thinner cartilage thickness. While Cth decreases with increasing age (p < 0.0001, 0.039, 0.001, 0.023, 0.091 in girls' knees, ankles, wrists, MCPs and PIPs and p = 0.002, 0.001, < 0.0001, 0.001, 0.045 in boys', respectively). Our data showed that weight, height and BMI are not the main factors contributing to Cth. A formula to calculate gender-specific cartilage thickness for Asian school age children is suggested. There was no difference in Cth after adjusting for height or weight between Asian or Caucasian group.

CONCLUSIONS

A formula to calculate gender-specific cartilage thickness for Asian school age children is suggested. Height, weight and BMI were not the major contributor for Cth among school age children.

Ultrasound imaging in paediatric rheumatology

The role of ultrasound imaging in the diagnosis and monitoring of paediatric rheumatic diseases with special emphasis on recent scientific work regarding the evidence base and standardization of this technique is being reviewed. An overview of the most important practical aspects for the use of musculoskeletal ultrasound in a clinical setting is also provided. Huge scientific efforts and advances in recent years illustrate the increasing importance of musculoskeletal ultrasound in pediatric rheumatology. Several studies focused on setting an evidence-based standard for the ultrasound appearance of healthy and normal joints in children of all age groups. Physiologic vascularization and ossification were two main aspects of these studies. Other publications demonstrate that ultrasound imaging is also an important and useful tool to detect pathology as synovitis, tenosynovitis or enthesitis in children and to monitor pediatric patients with rheumatic conditions. Important practical aspects include training in the use of correct ultrasound techniques, as well as knowledge and experience of normal pediatric sonoanatomy and the appearance of pathological findings on ultrasound.

Emergence of Musculoskeletal Ultrasound Use in Pediatric Rheumatology

PURPOSE OF REVIEW

To summarize recent international efforts on standardization and validation of pediatric musculoskeletal ultrasound and determine its role in diagnosis and monitoring of disease in pediatric rheumatology.

RECENT FINDINGS

Over the past decade, significant progress has been made on building the evidence base for musculoskeletal ultrasound in pediatric rheumatology. This includes the clear definition of the sonographic appearance of the normal pediatric joint and enthesis on ultrasonography, definitions for pathology, and the establishment of a specific scoring system for the pediatric knee. Ultrasonography has been shown to have an important role in the detection of subclinical synovitis and can predict flares in children considered to be in remission clinically. Musculoskeletal ultrasound is likely going to play an important role in complementing the clinical exam especially in juvenile idiopathic arthritis. Given the powerful therapeutic tools available, it will support early diagnosis and precisely determine remission status. In a treat to target approach, it will greatly help to define the targets that need to be reached.

Age dependent ultrasound B-mode findings of the elbow joint in healthy children and adolescents

Due to maturation of joints, various changes take place, not only in the field of paediatric rheumatology but also in paediatric orthopaedics musculoskeletal ultrasound plays an important role in both the diagnosis and the follow-up of diseases in this field. To differentiate between physiological and pathological findings, the knowledge of reference values of joint structures is indispensable. The objective was to define B-mode ultrasound age- and sex-related reference values for the elbow joint in healthy children and adolescents during maturation. In a cross-sectional, multicentre ultrasound study we examined both sides of the elbow joints of 437 healthy children and adolescents (194 boys/243 girls) being between one and less than 18 years old. The children were classified into six equal age groups and divided according to their gender. We measured the distance between the outer margin of the joint capsule and the bone surface to define the bone-capsule distance (BCD), the thickness of the joint cartilage as well as the thickness of the joint capsule. The bone-capsule junction zone and the shape of the joint capsule were analysed qualitatively. The bone capsule distance and the capsule thickness increased with age. In contrast, the joint cartilage thickness decreased. In most cases the junction zone was peaked. The joint capsule showed mostly a concave shape. Intra- and interobserver reliabilities were good. We propose B-mode ultrasound age- and sex-related reference values for the elbow joint in a large number of healthy children and adolescents for the first time. By applying these standard values to the ultrasound examination of the elbow joint, it may be possible to achieve greater certainty in the diagnosis of pathological processes.