NORMAL ANATOMY OF THE HIP-JOINT. 



777 



concavity superiorly, corresponding to the 

 junction of the pubis and ilium, and a similar 

 one inferiorly and externally, corresponding to 

 the junction of the ilium and ischium. These 

 concavities are separated by intervening con- 

 vexities, and hence the margin of the acetabu- 

 lum has the appearance of a waving line. 

 Immediately within the margin of the acetabu- 

 lum we perceive a broad band of smooth 

 bone (fades lunata) covered in the recent 

 state by articular cartilage, about seven-eighths 

 of an inch wide at its lower portion, or oppo- 

 site the ischium, an inch and a quarter to an 

 inch and a half superiorly and externally, 

 where it corresponds to the ilium, and from a 

 quarter to half an inch internally and superiorly 

 at the pubis. This band terminates at each 

 extremity of the notch already described in a 

 process (cornu), the superior of which looks 

 downwards, outwards, and backwards, whilst 

 the inferior, more prominent than the superior, 

 projects towards the notch, forming a kind of 

 gutter between its superior margin, and the 

 deepest part of the notch. Internal to this 

 band, there is a depression, as it were a cavity 

 within the acetabulum, rough and uneven, 

 uninvested by cartilage in the recent state, 

 being continuous with the notch leading 

 towards the obturator foramen. This is the 

 Jbvea or sinus, and lodges a quantity of fatty 

 cellular tissue formerly termed glands of Havers, 

 from their having been first described by that 

 anatomist. On the upper and lower portions 

 of this inner cavity, various inequalities and 

 foramina are seen, the latter being for the pas- 

 sage of the nutritious vessels of the bone, 

 which is very thin at this point, so much so in- 

 deed, that if held up to the light, it will be 

 found transparent. The depth of the acetabu- 

 lum is not uniform in its different regions. 

 This variety corresponds in a great measure to 

 the breadth of the smooth band of bone 

 (fades lunata) already described. Where 

 this is broadest, the cavity possesses the great- 

 est depth, and where it is entirely absent, the 

 cavity is very superficial, as opposite the notch. 



The non-articular circumference of the lip 

 of the acetabulum is rough and marked by 

 foramina for the passage of nutritious vessels, 

 and also for the attachment of the capsular 

 ligament. 



The head of the femur, representing about 

 three-fourths of a sphere, is supported and con- 

 nected to the shaft of that bone at an angle 

 varying with age, by a constricted and flattened 

 process termed the neck. A waving prominent 

 line surrounds the head at its junction with the 

 neck, and may be regarded as the boundary 

 line between these two parts, leaving on its 

 inner side the articular surface of the head of 

 the femur, which is smooth, having in the 

 adult its greater convexity directed upwards 

 and inwards. At one point, however, the ar- 

 ticular character of this surface is interrupted 

 by a depression, which is not covered with carti- 

 lage in the recent state. This depression, situ- 

 ated immediately behind and below the point 

 through which the axis of the head of the bone 



would pass, gives insertion to the ligamentum 

 teres. 



2. The cartilage. That portion of the sur- 

 face of the acetabulum which corresponds 

 to the facies lunata is alone invested by articu- 

 lar cartilage. This cartilaginous layer is thick- 

 est at its external circumference, becoming 

 gradually thinner as it proceeds internally. 

 The head of the femur, on the other hand, is 

 nearly entirely incrusted with cartilage, which, 

 as is usual on convex surfaces, is thickest 

 towards its centre, where it is interrupted by the 

 depression for the ligamentum teres, and be- 

 comes progressively thinner towards the circum- 

 ference. 



3. Fibro-cartilage. Immediately surround- 

 ing the margin of the acetabulum is a fibro- 

 cartilaginous ring about three lines broad, tri- 

 angular in shape, having its base attached to 

 the brim of the cavity, whilst its apex is free. 

 This is the so-called cotyloid ligament (ligamen- 

 tum cotyloideum, fibro-cartilagineum, labium 

 cartilagineum acetabuli.) It clearly belongs to 

 the fibre-cartilages of circumference, and is 

 the counterpart of the glenoid ligament in the 

 shoulder-joint (see FIBRO-CARTILAGE), and as 

 it completely removes the irregular character 

 of the margin of the acetabulum, it will be 

 found to be deepest where it corresponds to the 

 concavities of the acetabular border. Its free 

 border is sharp, and directed inwards, i. e., 

 towards the centre of the joint, narrowing the 

 orifice of the acetabulum, at the same time that 

 it increases the depth of that cavity. Its fixed 

 margin constitutes its base, and is connected to 

 the brim of the acetabulum ; its external sur- 

 face covered by synovial membrane corres- 

 ponds to the capsular ligament, whilst its inter- 

 nal, also covered by synovial membrane, em- 

 braces the head of the femur. Having arrived 

 at the notch, it is continued over each cornu of 

 the facies lunata, retaining somewhat of its 

 form, but much diminished in dimensions, and 

 having assumed much more the appearance of 

 pure cartilage than of fibro-cartilage. It ceases 

 at the point at which the concave margin of the 

 facies lunata becomes blended with the con- 

 vexity of each cornu. It is not stretched 

 across the notch as some anatomists erroneously 

 describe it. The whole extent of this fibro- 

 cartilage, then, corresponds exactly to the con- 

 vex margin of the facies lunata. 



4. Ligaments. The notch of the acetabu- 

 lum is converted into a foramen, strengthened 

 and in a great degree closed by ligamentous 

 fibres arranged in two layers, and extended 

 from the superior to the inferior cornu. The 

 whole forms the ligamentum transversale aceta- 

 buli of Winslow. Of these the external and 

 deepest arises from the superior, and is inserted 

 into the inferior cornu of the acetabulum. The 

 external surface of this layer, directed obliquely 

 backwards towards the cavity of the acetabulum, 

 corresponds and gives attachment to the liga- 

 mentum teres. Its internal surface is applied 

 to the external layer ; its external margin is 

 attached to the capsular ligament, and its inter- 

 nal superiorly to the pubis, but inferiorly it is 



