46 
sixth of an inch, at the outer margin or thickest 
~ They are both com of concentric 
bres, the extremities of which are fixed to the 
central parts of the head of the tibia, before and 
behind the crucial ligaments, with whose fibres 
they intermingle; the anterior extremities are 
usually joined together by a transverse liga- 
ment, but this is sometimes wanting. 
The ligamentum patelle, of vast importance 
in the actions of the knee-joint, is yet the most 
distant from its articular surfaces; it extends, 
broad and flat, from the lower somewhat point- 
ed portion of the patella to the inferior part of 
the tubercle of the tibia, being in the adult 
about two inches in length. It forms a strong 
inelastic but inflexible bond of union of the 
— with the tibia, and may with propriety 
looked upon as a continuation of the ex- 
tensor tendons which are inserted into the 
upper and lateral margins of the former bone; 
some fibres indeed pass over its anterior sur- 
face, but it is only through this bone and its 
ligament that the extensor muscles can act 
upon the leg. The patella is thus seen to be 
placed in a situation analogous to that of the 
sesamoid bones, in the tendons which play 
over bony surfaces, in the hands and feet. The 
ligament of the patella is covered anteriorly by 
dense integument, and the fascia of the leg: 
posteriorly a cushion of fat is interposed be- 
tween it and the joint at the upper part, while 
below it is separated from the bene by a bursa, 
whose situation was pointed out in the descrip- 
tion of the tibia. (See fig. 111, 6, vol. i. p. 252.) 
More closely applied to the joint are the lateral 
ligaments, the posterior and the crucial liga- 
ments ;and port 3 of the synovialcapsule which 
are described by some anatomists as alar and 
mucous ligaments. The lateral ligaments have 
a vertical direction at each side of the knee, and 
are placed nearer to the posterior than the ante- 
rior boundary of the joint; the upper attach- 
ment is in fact to the tuberosity at the centre 
of the smaller curve which the articular sur- 
faces of the condyles form at their back part. 
The internal lateral ligament descends from 
the tuberosity of the internal condyle of the os 
femoris to beneath the head of the tibia; it is 
nearly three inches in length, of a flattened 
form, narrow at its commencement, but en- 
larging considerably opposite the joint, to the 
synovial membrane of which as well as to the 
internal semilunar cartilage it adheres; infe- 
riorly it again contracts in width. Its upper 
attachment is covered by the fascia lata; below, 
it is inserted into the shaft of the tibia just 
beneath the head of the bone, and anterior to 
its inner angle; and the tendons of the sarto- 
rius, gracilis, and semitendinosus cross over it. 
The external lateral ligament (lig. laterale 
externum ) arises from the tuberosity on the 
external condyle of the femur, and descends, 
inclining backwards, partly covered by the 
tendon of the biceps, to be inserted with it 
into the head of the fibula; the attachment of 
its upper extremity is immediately above the 
origin of the popliteus tendon, which it crosses 
in its descent, so that this tendon enveloped by 
its synovial sheath is situated between the liga- 
NORMAL ANATOMY OF THE KNEE-JOINT. 4 
ment and the joint. The deviation of t 
ligament from the perpendicular direction” 
perceived most distinctly in the state of exte 
sion ; when the joint is flexed, the upper: 
tachment of the hgament is brought more it 
the perpendicular over its fibular attachme’ 
the ligament is relaxed and assumes the pi 
pendicular direction ; hence, in the flexed ee 
dition of the joint, the external condyle of 
femur, or the tibia on it, admits of a more fi 
motion. This ligament is contrasted by il 
less length and more rounded form with | 
internal lateral, and is composed like it 
shining tendinous fibres; a still shorter 
fibres sometimes passes more posteriorly fro 
the condyle to the head of the fibula, 
from the sheath of the popliteus tendon, at 
has been called the short external lateral lig 
ment. ‘y 
The posterior ligament (lig. posticum Wi 
slowii i a irtian of the eae of the semi 
membranosus muscle which is given off nea 
its insertion at the posterior and inner margt 
of the head of the tibia; the portion under co 
sideration forms a flat and dense fascia whi¢ 
passes upwards and outwards to the extern 
condyle, where it becomes adherent to the s) 
novial capsule and mingling with the tendine 
origin of the outer head of the gastrocnemius: 
posterior to it lie the popliteal vessels, and it 
front of it there is a quantity of firm granulates 
fat, into which some of its fibres penetrate. 
When the posterior ligament and the fat ju 
spoken of are removed, and the joint is ex- 
tended, the two crucial ligaments (ligament 
cruciata* ) are brought into view ; they may b 
seen on the anterior aspect by dissecting dow! 
the patella from the fore part of the na and 
putting it in a state of flexion; in the forme 
view, the posterior crucial ligament is be: 
seen; in the latter, the anterior: the uppe 
extremities of both are fixed in the fossa be 
tween the condyles of the os femoris; thei 
lower extremities are attached to the head « 
the tibia between the two articular surfaces. 
The anterior crucial ligament passes fre 
the inner and back part of the outer condyle 
downwards and forwards to the depression ii 
frontof the spine of the tibia, where some portion 
becomes continuous with the anterior extr 
mity of the internal semilunar cartilage. Th 
posterior extends from the fore and outer. par 
of the internal condyle downwards and back 
wards to the notch at the posterior margin 6 
the head of the tibia, where it becomes like 
wise attached to the posterior extremity of thi 
external semilunar cartilage. The crucial liga 
ments thus derive their name from decussatin 
one another like the strokes of the letter X; 
the crossing is, however, considerably abov 
their centre: the anterior passes to the oute 
side of the posterior. 7 
The synovial capsulet entirely surrounds t 
* [It is useful to bear in mind that these ligaments 
are called anterior and posterior with reference 
their insertions into the tibia, the one in front o 
the other behind, the spine of that bone.— Ed.] 
+ [Weber recommends as a good way of deme 
strating the full extent and connexions of the 
