Advanced Search Abstract Despite its relatively high prevalence, polyarticular nature, limited treatment options and recognized genetic contribution, the study of generalized OA GOA has lagged behind that of isolated knee OA. Whilst the pathogenesis of OA has been viewed in relation to either articular cartilage or bone disease, this article offers a viewpoint on why GOA may, in fact, be primarily a disorder of ligaments, and to a lesser extent tendon and joint capsule dysfunction. A relatively fast presentation of GOA, typically in the perimenopausal period, and its recognition on clinical grounds alone makes this type of OA potentially useful for pathogenic studies in OA, in general.
In addition, the deep crural and plantar fasciae contribute to Achilles stress dissipation and could also be regarded as components. Here we describe the sequence in which these various tissues differentiate.
Serial sections of feet from spontaneously aborted foetuses crown rump lengths 22— mm were examined. All slides formed part of an existing collection of histologically sectioned embryological material, obtained under Spanish law and housed in the Universidad Complutense, Madrid.
From the earliest stages, it was evident that the Achilles tendon and plantar fascia had a mutual attachment to the calcaneal perichondrium.
Anatomy of the achilles enthesis and retrocalcaneal bursa The Achilles tendon is the largest in the body. It has a distal insertion of approximately 1 × 2 cm and inserts approximately 2 cm distal to posterosuperior edge of the calcaneal tuberosity. Enthesis Organ concept. Their central principle is that all of the tissues surrounding a ligament attachment site in a joint (an enthesis) participate in the task of shock attenuation and can be considered a functional unit, which they termed an enthesis organ. The enthesis organ is composed of the enthesis insertion and adjacent tissues. Whilst the insertion provides firm anchorage to the underlying bone the enthesis organ comprises several other tissues.
The first components of the enthesis organ to appear in the mm foetus were the retrocalcaneal bursa and the crural fascia. The tip of the putative fat pad protruded into the developing bursa in the mm foetus and fully differentiated adipocytes were apparent in the mm foetus. All three fibrocartilages were first recognisable in the mm foetus — at which time adipogenesis had commenced in the heel fat pad.
The sequence in which the various elements became apparent suggests that bursal formation and the appearance of the crural fascia may be necessary to facilitate the foot movements that subsequently lead to fibrocartilage differentiation.
The direct continuity between plantar fascia and Achilles tendon that is characteristic of the adult reflects the initial attachment of both structures to the calcaneal perichondrium Enthesis organ anatomy than to the skeletal anlagen itself.
The archetypal enthesis organ in man is that of the Achilles tendon. These may be regarded as ancillary fibrocartilages that are adaptations allowing the tendon to be compressed against the calcaneus, as the superior tuberosity serves as a pulley during foot movements.
The sesamoid and periosteal fibrocartilages form the walls of the distal part of the retrocalcaneal bursa. This has a wide variety of functions that have been considered previously Theobald et al. Briefly, the fat pad is thought to facilitate the movement of tendon relative to bone, prevent tendon—bone adhesion, aid in the spread of bursal fluid and act as a space filler and immune organ Theobald et al.
Although it is known that the periosteal and sesamoid fibrocartilages develop postnatally in the rat Rufai et al. Neither do we know the relationship between the development of the Achilles tendon enthesis organ and that of the plantar fascia.
As several authors have commented on the continuity of these two structures Wood Jones, ; Snow et al. The purpose of the present paper is to address these issues by examining a rare collection of histological sections of embryonic feet that are housed in the Department of Human Anatomy and Embryology at the Universidad Complutense in Madrid.
Materials and methods Routine histology The material examined in this study is part of a long-established collection of histologically sectioned, human embryonic material housed in the Department of Human Anatomy and Embryology at the Universidad Complutense, Madrid. All tissue was donated to the University with parental consent following spontaneous miscarriage and in accordance with Spanish law.
A complete set of serial sections from foetuses of 17 different crown rump lengths were available for study. The crown rump lengths with corresponding gestational ages given in brackets — based on Patten were 21 mm 51 days22 mm 52 days24 mm 54 days ; 32 mm and 34 mm 8 weeks37 mm, 41 mm and 42 mm 9 weeks45 mm 9.
All sections had been cut in the sagittal plane, except for the mm fetus, where the sections had been cut coronally.
MRI With Institutional Review Board approval, magnetic resonance imaging MRI was performed at 3T in six normal adult volunteers two females, four males; ages 22—63 years with a circular receiver coil.
MR images show that the distal part of the tendon is often directly continuous with the plantar fascia via a thickened periosteum Fig. Additionally, a network of fibrous septa within the heel fat pad is evident that is functionally important for compression tolerance of the pad.
This network is anchored to the posterior aspect of the distal Achilles tendon attachment, indicating a close functional integration between the heel pad and the Achilles enthesis organ in the adult Fig.Enthesis Anatomy & Physiology Historically, all entheses have long been considered as focal attachments to bone.
However, it is increasingly recognised that in many cases the enthesis is really just part of an enthesis organ. An organ is a group of related tissues that function together to .
We examined the structure and histopathology of the insertional region in 50 tendons from cadavers (age at time of death, years).
The enthesis contained fibrocartilage typical of attachment sites. Immunohistochemistry of the enthesis organ of the human Achilles tendon. Clinical anatomy of the retrocalcaneal bursa.
organ”, where closely associated fibrocartilaginous structures contribute to reduction of mechanical stress. Based on the anatomy of the enthesis organ, three different types of fibrocartilaginous entheses have been identified: 1.
The classical enthesis, 2. The ‘functional’ enthesis and 3. The function of the enthesis organ is to provide a stable anchorage to the skeleton and to minimise damage at the insertion site which is subject to high levels of physical stress. The enthesis organ. The enthesis organ is composed of the enthesis insertion and adjacent tissues.
The enthesis organ is composed of the enthesis insertion and adjacent tissues. Whilst the insertion provides firm anchorage to the underlying bone the enthesis organ comprises several other tissues. The enthesis, attachment site of ligaments, tendons, and joint capsules to bone, has emerged as a complex structure or entheseal organ that dissipates stress to maintain homeostasis.
Entheses are also anatomically and functionally integrated with adjacent bursa, fibrocartilage, and synovium in a.