strength. In this joint, however, stability comes chieﬂy from
the deep socket that securely encloses the femoral head and the
strong capsular ligaments.
(±MJ), or jaw joint, is a modiﬁed
hinge joint. It lies just anterior to the ear
. At this joint,
the condylar process of the mandible articulates with the inferior
surface of the squamous part of the temporal bone. Te mandible’s
condylar process is egg shaped, whereas the articular surface of the
temporal bone has a more complex shape. Posteriorly, it forms the
; anteriorly it forms a dense knob called
. Te lateral aspect of the loose articular cap-
sule that encloses the joint is thickened into a
Within the capsule, an articular disc divides the synovial cavity into
superior and inferior compartments (Figure 8.13a, b).
Tese include the
o-ral), a strong
V-shaped ligament anteriorly; the
o-ral), a triangular thickening of the inferior part of the capsule;
o-ral), a spiraling
posterior ligament (Figure 8.12c, d). Tese ligaments are arranged
in such a way that they “screw” the femur head into the acetabulum
when a person stands up straight, thereby providing more stability.
ligament of the head of the femur
, also called the
, is a ﬂat intracapsular band that runs from the femur head
to the lower lip of the acetabulum (Figure 8.12a, b). Tis ligament is
slack during most hip movements, so it is not important in stabiliz-
ing the joint. In fact, its mechanical function (if any) is unclear, but
it does contain an artery that helps supply the head of the femur.
Damage to this artery may lead to severe arthritis of the hip joint.
Muscle tendons that cross the joint and the bulky hip and
thigh muscles that surround it contribute to its stability and
Coxal (hip) bone
Ligament of the
head of the femur
(a) Frontal section through the right hip joint
(d) Anterior view of right hip joint, capsule in place
(c) Posterior view of right hip joint, capsule in place
of the head
of the femur
(b) Photo of the interior of the hip joint, lateral view
The hip joint.