Page 223 - Clinical Anatomy

ECA4 7/18/06 6:47 PM Page 208

208 The lower limb

scrubbing floors or hewing coal (‘housemaid’s knee’, the ‘beat knee’ of
north-country miners, or prepatellar bursitis); whereas the bursa over the
ligamentum patellae is involved by years of kneeling in a more erect
position —as in praying (‘clergyman’s knee’ or infrapatellar bursitis).
Young women who affect fashionable but tight shoes are prone to bursitis
over the insertion of the tendo Achillis into the calcaneus and may also
develop bursae over the navicular tuberosity and dorsal aspects of the
phalanges.
A‘bunion’ is a thickened bursa on the inner aspect of the first metatarsal
head, usually associated with hallux valgus deformity. Note that this is an
adventitial bursa; it is not present in normal subjects.

Mensuration in the lower limb
Measurement is an important part of the clinical examination of the lower
limb. Unfortunately, students find difficulty in carrying this out accurately
and still greater difficulty in explaining the results they obtain, yet this is
nothing more or less than a simple exercise in applied anatomy.
First note the differences between real and apparent shortening of the
lower limbs. Real shortening is due to actual loss of bone length — for
example, where a femoral fracture has united with a good deal of overrid-
ing of the two fragments. Apparent shortening is due to a fixed deformity of
the limb (Fig. 148). Stand up and flex your knee and hip on one side,
imagine these are both ankylosed at 90° and note that, although there is no
loss of tissue in this leg, it is apparently some 2ft (60cm) shorter than its
partner.

Fig. 148◊Apparent
shortening—one limb
may be apparently
shorter than the other
because of fixed
deformity; the legs in this
illustration are actually
equal in length but the
right is apparently
considerably shorter
because of a gross flexion
contracture at the hip.
Apparent shortening is
measured by comparing
the distance from the
umbilicus to the medial
malleolus on each side.