246 THE ARTICULATIOXS 



THE ARTICULATIONS OF THE LOWER LI3IB 



The articulations of the lower limb are the following: — 



1. The hip-joint. 



2. Tlie knee-joint. 



3. The tibio-fibular union. 



4. The ankle-joint. 



5. The tarsal joints. 



6. The tarso-metatarsal joints. 



7. The intermetatarsal joints. 



8. The metatarso-phalangeal joints. 



9. The interphalangeal joints. 



1. THE HIP-JOINT 

 Class. — Diarthrosis. Subdivision. — Enarthrodia. 



The hip is the most typical example of a ball-and-socket joint in the body, the 

 round head of the femur being received into the cup-shaped cavity of the aceta- 

 bulum. Both articular surfaces are coated with cartilage, that covering the head 

 of the femur being thicker above where it has to l)ear the weight of the body, 

 and thinning out to a mere edge below; the pit for the ligamentum teres is the 

 only part uncoated, but the cartilage is somewhat heaped up around its margin. 

 Covering the acetal)ulum, the cartilage is horseshoe-shaped, and thicker above than 

 }>elow, being deficient over the depression at the bottom of the acetabulum, Avhere 

 a mass of fatty tissue — the so-called synovial or Haversian gland — is lodged. 



The ligaments of the joint are:^ 



Capsular. Ligamentum teres. 



Transverse. Cotyloid cartilage. 



Tlie capsular ligament is one of the strongest ligaments in the body. It is 

 large and somewhat loose, so that in every position of the body some portion of it 

 is relaxed. At the pelvis it is attached, superiorly, to the base of the anterior 

 inferior iliac spine; curving backwards, it becomes blended Avith the deep surface 

 of the reflected tendon of the rectus femoris ; posteriorly, it is attached a few lines 

 from the acetabular rim; and below, to the upper edge of the groove between the 

 acetabulum and tuberosity of the ischium. Thus it reaches the transverse liga- 

 ment, being firmly l)len(led with its outer surface, and frequently sends fibres 

 beyond the notch to blend with the obturator membrane. Anteriorly it is attached 

 to the pubes near the notch, to the pectineal eminence, and thence backwards to 

 the base of the iliac spine. A thin strong stratum is given ofif from its superficial 

 aspect behind; this extends beneath the gluteus minimus, and small rotators, to 

 l)e attached above to the dorsum of the ilium higher than the reflected tendon of 

 the rectus, and posteriorly to the ilium and ischium nearly as far as the sciatic 

 notch. As this expansion passes over the long tendon of the rectus, the tendon 

 may be described as l)eing in part contained witliin the substance of the capsule. 



At the femur, the capsular ligament is fixed to the anterior portion of the upper 

 border of the great trochanter, and to the superior cervical tubercle. Thence it 

 runs down the spiral line as far as the inner l)order of the femur, where it is on a 

 level with the lower part of the lesser trochanter. It then runs upwards and back- 

 wards along an obliipie line about two-thirds of an inch (1-6 cm.) in front of the 

 lesser trochanter, and contiiuies its ascent along the back of the neck nearly }>arallel 

 to the posterior intertrochanteric line, and from one-half to two-thirds of an inch 

 (12 to 16 mm.) above it; finally, it passes nlong the inner side of the digital fossa 

 to reach the anterior sujjcrior angle of the great trochanter. 



