C h a p t e r 4 3
Disorders of the Skeletal System: Trauma, Infections, Neoplasms, and Childhood Disorders
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static stabilizers, which control patellar tracking; that is,
the movement of the patella within the femoral troch-
lea.
15
The disorder, also called “runner’s knee,” occurs
most frequently in young adults and is often associated
with jogging, volleyball, and basketball. Persons with
this disorder typically complain of pain, particularly
when climbing stairs or sitting with the knees bent. The
pain is usually difficult to localize, and swelling of the
knee is not characteristic of the disorder. Occasionally,
the person experiences weakness of the knee.
Diagnosis is usually based on history and physical
examination. Radiography may be used as an adjunct to
the history and physical. Treatment consists of relative
rest and physical therapy.
15
Reduction of loading of the
patellofemoral joint and surrounding tissues is the first
step to reduce pain. Inappropriate or excessively worn
footwear may contribute to the problem and need to
be replaced. Although a variety of braces, sleeves, and
straps have been used in treatment of the disorder, stud-
ies have found no significant benefit from their use.
Hip Injuries
The hip is a ball-and-socket joint in which the femo-
ral head articulates deeply in the acetabulum.
10
The
proximal part of the femur consists of a head, neck, and
greater trochanter. The vascular anatomy of the femo-
ral head, which receives its main blood supply from the
lateral and medial circumflex femoral arteries and the
obturator artery, is of critical importance in any disorder
of the hip (Fig. 43-4). Disease or injuries that compro-
mise blood flow may damage the viability of the femoral
head and lead to avascular necrosis or osteonecrosis.
Dislocations of the Hip.
Dislocations of the hip in
which the femoral head is displaced from the acetabu-
lum are commonly the result of severe trauma and are
usually posterior in direction. They typically result from
the knee being struck while the hip and knee are in a
flexed position.
8
This force drives the femoral head out
of the acetabulum posteriorly. Anterior dislocations are
less common and usually result from a force on the knee
with the thigh abducted.
Hip dislocation is an emergency.
5,8
The disorder is
typically accompanied by severe pain and inability to
move the lower extremity. In the dislocated position,
great tension is placed on the blood supply to the femo-
ral head and avascular necrosis may result. To prevent
this complication, early reduction is indicated. Weight
bearing is usually limited after reduction to prevent the
dislocation from reoccurring and allow healing to occur.
Fractures of the Hip.
Hip fracture is a major public
health problem in the Western world, particularly among
the elderly.
16–18
It results in hospitalization, disability,
and loss of independence. Risk factors for hip fracture
include physical inactivity, excessive consumption of
alcohol, use of certain psychotropic drugs, residence
in an institution, visual impairment, and dementia.
16
Osteoporosis is an important contributing factor.
Most hip fractures result from falls. Occasionally, the
person may actually fracture the hip before falling, the
fracture representing the completion of an incomplete
break. The characteristics of the fall (the direction, site
of impact, and protective response) and environmental
factors are recognized as important influences for the
risk of hip fracture from a fall.
A hip fracture usually involves the proximal femur.
Such fractures are commonly categorized according to
the anatomic site in which they occur.
9,16–18
Femoral neck
fractures are located in the area distal to the femoral head
but proximal to the greater and lesser trochanters and
are considered intracapsular because they are located
Head
Ligament of head
of femur
Medial circumflex
femoral artery
Retinacular folds
Acetabular labrum
Artery to head of femur
(acetabular branch of
obturator artery)
Acetabular fossa
Articular cartilage
Ilium (coronal section)
Synovial membrane
Fibrous capsule
Lateral circumflex
femoral artery
Synovial
membrane
Fibrous capsule
Neck of femur
Obturator artery
Lesser trochanter
Greater trochanter
FIGURE 43-4.
Blood supply of
the head and neck of the femur
(anterior view). A section of the
bone has been removed from
the femoral neck. (Modified
from Moore KL, Agur AM,
Dalley AF. Essential Clinical
Anatomy. 4th ed. Philadelphia,
PA: Wolters Kluwer Health |
Lippincott Williams &Wilkins;
2010:380.)
