According to the
author, the ligamentum capitis femoris (LCF) is a tendon of the pectineus
muscle, separated from it in consequence of skeletal modifications.
THE LIGAMENTUM TERES
By J. B. SUTTON,
Demonstrator of Anatomy, Middlesex Hospital. (PLATE VIII.)
The round
ligament of the coxo-femoral articulation has long been an anatomical puzzle,
consequently many diverse notions exist concerning it. Some anatomists ascribe
to this hollow band of fibrous tissue very important functions in the mechanism
of the hip-joint; others deprive it of all glory, simply assigning to it the
menial duty of conveying blood-vessels to the head of the femur.
Certain authors
content themselves with a brief description of its attachments; others give
elaborate and detailed accounts, extending over several pages, of its anatomy
and supposed function. My object in the present communication is to show that this
singular ligament is nothing more than the tendon of the pectineus muscle,
separated from it in consequence of skeletal modifications.
Careful attention
to the mode of development of the ligamentous bonds of diarthrodial
articulations has led me to formulate two rules with regard to them-viz.,
1. Many ligaments
arise as thickenings in a capsule, due to prolonged tension in definite
directions, the capsular ligament itself being merely the perichondrium passing
from one cartilage to another.
In this manner
distinct bands of tissue form on the sides, and other aspects of joints which
afterwards differentiate into distinct ligaments.
2. Many ligaments
are the tendons of muscles which were originally in relation with the joint;
but the parent muscle has either formed new attachments or become obsolete,
whilst its tendon remains as a passive element in the articulation.
To this group
belongs the lig. teres, a structure fairly constant throughout Mammalia, though
absent in the elephant, seal, &c. (sometimes wanting in man, says Meckel).
It is almost
universal among birds; indeed, among these highly specialised and beautiful
creatures it reaches a high standard of development.
The attachments
and relations of the ligament in man are so well known that description is
needless here, merely noting that in the foetus at birth it is very strong and
dense.
In the horse one
gets the first glimpse of its true nature.
In this animal
the ligament consists of two bands-one hidden within the joint, termed the
cotyloid portion; the other passes out of the cavity to join the linea alba at
its junction with the pubes, hence termed the pubio femoral portion. From this band
the pectineus takes part of its origin.
These facts led
me to investigate the ligament in the ostrich, holding as it does a
corresponding position among birds as the horse does among mammals, for
cursorial powers.
In the ostrich
(Struthio camels) the ligamentum teres has a true tendinous structure. It is
dense and strong, contains a large quantity of elastic tissue, and has its
individual fasciculi arranged regularly, corresponding to the arrangement
encountered in the rounded tendons of limb muscles. In my specimen the ligament
was three-fifths of an inch in thickness.
On making a
section horizontally through the acetabulum, so as to include the ambiens
muscle at its origin, and the ligament (see fig. 1), it may be clearly seen
that they are continuous with one another across the cotyloid cavity by fibrous
tissue.
The ambient is a
muscle of considerable interest, partly on account of its variability, but also
on account of its curious course and relations.
It is fusiform,
and arises from the tip of the short, anteriorly directed spine, which is
situated above the anterior border of the acetabulum, and runs along the inner
border of the thigh to the knee, where it is covered by the sartorius. Here it
degenerates into a round and polished tendon, crossing in front of the knee, running
in the substance of the fascia of the extensor tendon, immediately in front of
the patella, to the outer side, where it joins the fibres of origin of the flexor
perforatus digitorum.
Remembering that
birds and mammals had a common origin, one turned for farther information to
that curious lizard, Sphenodon. In this remarkable creature the hip-joint is of
simple character, and the muscle corresponding to the ambiens of birds and the
pectineus of man arises by two heads-one from the lateral spine of the pubes;
the other is reflected from the muscle to the inside of the capsule, so as to gain
an attachment to the head of the femur; thus holding a corresponding relation
to the joint as does the ligamentum teres of man and birds (see fig. 2).
The varying
relations of muscle and ligament may be arranged in a tabular form, thus: -
1. Sphenodon. - Tendon
of ambiens (pectineus) passes inside the capsule to the head of femur.
2. Struthio. - Lig.
teres continuous with ambiens (pect.) across the cotyloid cavity by fibrous
tissue.
3. Equus. - Lig.
teres in two parts-one continuous with pectineus outside the joint.
4. Homo. - Lig.
teres a fibrous band, carrying blood-vessels to the head of femur.
Besides the
direct evidence, other facts may be mentioned respecting the ambiens to show
that it is a muscle of great variability.
In comparing it
with pectineus, it would seem that the crural portion alone persists in
mammals.
Its crural and
lower parts in birds; but all parts, upper, crural, and lower-luxuriate in full
perfection among lizards and crocodiles.
For more detailed accounts of this peculiar muscle, the reader must refer to papers by Garrod, published in the Proc. of Zoolog. Society, 1873, "On certain Muscles of the Thigh in Birds," and an extremely valuable paper by Dr. Hans Gadow, in Journal of Anatomy and Physiology for July 1882.
External links
Sutton JB. The
Ligamentum Teres. J Anat Physiol. 1883;17(2)190.1-193. [ncbi.nlm.nih.gov]
Authors &
Affiliations
John Bland Sutton or John Bland-Sutton (1855-1936), was a British surgeon [wikipedia.org]. In 1881 became a prosector at the Regent’s Park Zoological Gardens. In 1896, Bland-Sutton was appointed Surgeon to the Chelsea Hospital for Women. In 1905, he became Surgeon to the Middlesex Hospital (Burke PF. Sir John Bland-Sutton: ‘A Great Surgeon’, Surgical News, 2021;22(4)48-49. issuu.com).
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| Sir John Bland-Sutton Bain News Service (publisher), unknown date; original in the wikimedia.org collection (CC0 – Public Domain, no changes). |
Keywords
ligamentum capitis femoris, ligamentum
teres, ligament of head of femur, anatomy, animals, Sphenodon, Struthio,
evolution
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