The
hip
The hip is rarely involved in extrinsic trauma but is commonly
affected by intrinsic trauma (fractured neck of femur) and by chronic conditions
(osteoarthritis). The examination of the joint is made more difficult by the
fact that it is covered by muscles. It is also likely to present with pain
referred to the knee, and can be the site of pain referred from the spine.
Look
Limp
Watch the patient walk, and look for a limp. The limp of a stiff hip is
difficult to spot as the patient rocks their pelvis with the femur on the
affected side, but fixed flexion deformity is common and leads to the patient
walking with a characteristic stooped gait.
Skin
The scars from surgery on the hip are usually on the lateral side of the
hip.
Soft
tissue
wasting with loss of lumbar lordosis caused by back problems. The tilt
of the pelvis may make it look as if there is bilateral gluteal wasting.
Bone
There is little to see because the hip is so deeply buried, but a limp
may give a clue to underlying bony deformity.
Feel
Skin
As the joint is so deeply buried the only item that needs checking is
distal sensation. Damage to the femoral nerve produces numbness over the front
of the thigh. Damage to the sciatic nerve will produce numbness in the lower
leg.
Soft
tissues
Peripheral pulses can, again, be tested in the foot.
Bone
The hip can be palpated anteriorly in the groin beneath the femoral
pulse, but the hip is deep and difficult to feel. Tenderness on the lateral side
of the hip arises from the greater trochanter or is referred from the spine.
Pain posteriorly is usually the sciatic nerve or, once again, has been referred
from the spine.
Leg
length discrepancy
Leg length discrepancy can be caused by bones in the two limbs being of
unequal length, such as might occur after a fracture. It can also be caused by
deformity such as a fixed flexion deformity of the hip. Leg length discrepancy
caused solely by short bones is known by convention as ‘true’ leg length
discrepancy. That caused by joint deformity is known as ‘apparent’
shortening. Most leg length discrepancy is caused by a mixture of the two.
True
leg length discrepancy. It is usual to measure the ‘true’ leg length
discrepancy first by putting both legs as straight as possible, and then
measuring the leg which cannot be put straight. The other leg is then put into
an identical position, so that the deformity has no effect on leg length
discrepancy. If the end of the tape measure is held firmly between the pulp of
the thumb and the side of the index finger the tip of the thumb can be used to
trace the inguinal ligament upwards until it catches in the notch immediately
below the anterior superior iliac crest. A similar manoeuvre can be used at the
lower end of the leg. The tip of the examiner’s other thumb is traced up the
calcaneus, until it jams in the notch immediately below the medial malleolus.
The measure is repeated on the other limb which is first put in the identical
position.
In
order to decide which bone(s) are responsible for the shortening, the patient
should lie supine and the knees should be bent up to a right angle. The examiner
should then look at the knees from the side. If the
femur on the short side lies lower then the shortening is below the
knee. If the tibia lies further back then the shortening lies above the knee. If
the shortening is above the knee then palpation of the greater trochanters will
reveal whether the shortening is in the femoral neck or in the femoral shaft. If
the shortening is below the knee then palpation of the medial and lateral
malleolus will reveal whether the shortening is above or below the ankle.
Apparent
leg length discrepancy. Apparent leg discrepancy is that caused by joint
deformity and is best calculated from the difference in true leg length, as
measured above, and the difference in leg length when both legs are put as
straight as possible.
Move
Active
and passive
In the hip active and passive movements are measured together in the
modified Thomas’s test, which will be described below.
Modified
Thomas’s test. The patient bends up both their knees and hips actively,
rolling themselves into a ball. The examiner can then carefully (watching the
patient’s face) push the hips into further flexion (passive flexion). The
flex-ion of the two hips can now be checked and compared. The patient is now
asked to hold the affected hip flexed by holding their shin in their hands.
This fixes the pelvis in full flexion. The other leg is now carefully extended
as far as comfortable and a note made of the angle that the femur makes to the
couch in full extension. The normal leg is now flexed back up again as far as
possible, and held there by the patient. The abnormal hip is now allowed to
extend (carefully watching the patient’s face) until it too will extend no
further (Fig. 20.17). Again, the angle that the femur makes with the couch is
noted and compared with the recording made on the other side. Both legs are now
lowered on to the bed and a note is made of the range of flexion and extension
of both hips, noting that the examination was performed with the pelvis in full
flexion.
Abduction.
Lay your forearm across the patient’s pelvis with the tips of your fingers
resting on one anterior superior iliac spine and your forearm resting on the
other one nearer
Stability
The Trendelenburg test. This is a test of stability of the hip joint or
of weakness of the gluteal muscles, such that the patient has great difficulty
taking all of their weight on the affected leg. The most sensitive way of
performing this test is to ask the patient to stand on both legs facing you, and
to place their hands palm downwards on your hands held palm upwards. The patient
is asked first to stand on their healthy leg, then repeat the manoeuvre on the
affected leg. If the test
Tests
for referred pain
Pain in the hip can be referred down from the spine, while pathology in
the hip can produce pain in the knee. A simple test which can help distinguish
pathology in the hip from pathology elsewhere is the ‘pastry rolling test’.
With the patient lying supine on the couch start with the unaffected side. Place
the palm of one of your hands on the patient’s shin, and the other on their
thigh. Keep your hands flat with the fingers straight, and roll the leg as one
to and fro under your hands as if you were rolling pastry. If there is no
problem in the hip, the patient will relax completely after a couple of rolls,
and their four will flop to and fro at the end of the leg (Fig.
20.21). Repeat
the test on the affected side. If there is pain and/or stiffness in the hip
joint the patient will not relax, the foot will not flop to and fro, and there
will be a distinct resistance to movement at the end of internal and external
rotation. Pathology in the knee dues not do this because the knee joint is being
rolled as one. Similarly, the sciatic nerve is not irritated by internal and
external rotation of the hip, so pathology in the spine has no effect on this
test.