Normal sonoanatomy of small joints in healthy children: changes in cartilage and vascularisation according to age and gender.

OBJECTIVES: The metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints may be involved in juvenile idiopathic arthritis. Our goal was to describe their normal sonoanatomy in healthy children, according to age and gender. METHODS: We studied 41 consecutive healthy children (20 girls, 21 boys; age 2-15 years) divided into four age groups: 2-4 years (n=9), 5-7 years (n=11), 8-12 years (n=12), and 13-15 years (n=9). Longitudinal ultrasound axis of the MCP and MTP joints were obtained. The evolution of the cartilage thickness and vascularisation of these joints were studied according to age and gender. The MCP or MTP joints were the statistical unit. RESULTS: At all sites, on B-mode images, cartilage thickness was associated with age (p<0.0001). Cartilage thickness at different sites was significantly greater in boys than in girls (p≤0.05). Blood vessels were seen within the cartilage, with differences across age groups. CONCLUSIONS: This study provides children's age- and gender-specific sonoanatomy data of MCP and MTP and confirms the importance of using colour Doppler or Power Doppler to study cartilage vascularisation.

Changes in collagen fibril network organization and proteoglycan distribution in equine articular cartilage during maturation and growth.

The aim of this study was to record growth-related changes in collagen network organization and proteoglycan distribution in intermittently peak-loaded and continuously lower-level-loaded articular cartilage. Cartilage from the proximal phalangeal bone of the equine metacarpophalangeal joint at birth, at 5, 11 and 18 months, and at 6-10 years of age was collected from two sites. Site 1, at the joint margin, is unloaded at slow gaits but is subjected to high-intensity loading during athletic activity; site 2 is a continuously but less intensively loaded site in the centre of the joint. The degree of collagen parallelism was determined with quantitative polarized light microscopy and the parallelism index for collagen fibrils was computed from the cartilage surface to the osteochondral junction. Concurrent changes in the proteoglycan distribution were quantified with digital densitometry. We found that the parallelism index increased significantly with age (up to 90%). At birth, site 2 exhibited a more organized collagen network than site 1. In adult horses this situation was reversed. The superficial and intermediate zones exhibited the greatest reorganization of collagen. Site 1 had a higher proteoglycan content than site 2 at birth but here too the situation was reversed in adult horses. We conclude that large changes in joint loading during growth and maturation in the period from birth to adulthood profoundly affect the architecture of the collagen network in equine cartilage. In addition, the distribution and content of proteoglycans are modified significantly by altered joint use. Intermittent peak-loading with shear seems to induce higher collagen parallelism and a lower proteoglycan content in cartilage than more constant weight-bearing. Therefore, we hypothesize that the formation of mature articular cartilage with a highly parallel collagen network and relatively low proteoglycan content in the peak-loaded area of a joint is needed to withstand intermittent stress and shear, whereas a constantly weight-bearing joint area benefits from lower collagen parallelism and a higher proteoglycan content.

Swedish metacarpophalangeal standards compared with previously published norms.

PURPOSE: Metacarpophalangeal lengths are used to create pattern profiles that are useful for assessment of skeletal dysplasias and malformation syndromes. The purpose of this study was to establish Swedish standards and compare them with previously published norms. MATERIAL AND METHODS: A group of healthy Swedish children was followed longitudinally from the age of 1 month to 18 years. The length of the tubular bones of the hand was measured on radiographs. In addition to the conventional measurements including epiphyses, diaphyseal lengths alone were recorded. RESULTS: Means and standard deviations of the metacarpophalangeal lengths are presented by gender and age. CONCLUSION: In spite of reasonably good correlation to previously published norms, demonstrated deviations encourage us to recommend the use of local standards whenever available.

The potential of digital dental radiography in recording the adductor sesamoid and the MP3 stages.

The current study was undertaken to evaluate the reliability of using a recent advance in clinical radiographic technique, digital dental radiography, in recording two growth indicators: the adductor sesamoid and MP3 stages. With an exposure time five times less than that used in the conventional approach, this method shows greatest flexibility in providing a high quality digitized radiographic images of the two growth indicators under investigation. Refereed Paper

The suspensory apparatus and digital flexor muscles of the llama (Lama glama) 2: The pelvic limb / El aparato suspensorio y los músculos flexores digitales de la llama (Lama glama) 2: El miembro pélvico

This paper provides data (text and illustrations) about the digital flexor muscles of the pelvic limb and the / metatarsophalangeal joint, evaluating the suspensory (support) apparatus and weight bearing structures. Similar to the above mentioned paper, a literature search provided incomplete information about these anatomical structures. As in the thoracic limb, unique anatomically variations exist in the pelvic limb of the llama. The caudal tibial muscle is fused with the lateral head of the deep digital flexor muscle (DDF), and the soleus muscle is missing. A symmetrical unexpected lumbricalis pedis muscle was found; the tendons are fusing with the axial branches of the lateral tendon of the long digital extensor muscle. A quadratus plantae muscle, also unexpected is present on the medial aspect of the tarsal region. The superficial digital flexor muscle (SDF) resembles that of the domestic ruminants. The metacarpo/ metatarsophalangeal joints, referred to as the fetlock joints (FJ) are very different from those of the domestic ruminants. Particular structures were found and they will be described and illustrated in the text. The anatomy of the suspensory (support) apparatus in the pelvic limb is evaluated in this paper.

El presente artículo ofrece datos (texto e ilustraciones) sobre el músculo flexor digital del miembro pélvico y la articulación metatarsofalángica, evaluando el aparato suspensorio (de apoyo) y el peso que soportan estas estructuras. La literatura proporciona información incompleta acerca de estas estructuras anatómicas. Al igual que en el miembro torácico, existen variaciones anatómicamente únicas en el miembro pélvico de la llama. El músculo tibial caudal se fusiona con la cabeza lateral del músculo flexor digital profundo (FDP), y el músculo soleo no existía. Fue encontrada una simetría inesperada del músculo lumbrical del pie; los tendones se encontraban fusionados con las ramas axiales del tendón lateral del músculo extensor digital largo. Un músculo cuadrado plantar, se encontraba presente en la cara medial de la región tarsal. El músculo flexor digital superficial (FDS) se asemeja al de rumiantes domésticos. Las articulaciones metacarpo/metatarsofalángicas, denominadas articulaciones del nudillo (AN) son muy diferentes de las de rumiantes domésticos. Fueron encontradas estructuras particulares que se describen e ilustran en el texto. Se evalúa la anatomía del aparato suspensorio (de apoyo) en el miembro pélvico.