Page 66 - Canine Lameness

38 3 The Orthopedic Examination

Of important note is that pain on hyperextension of the hip joint is not pathognomonic for hip
dysplasia/arthritis: other diseases, frequently mistaken for hip pathology (because of pain on “hip
extension”), include iliopsoas injury, lumbosacral disease (Chapter 16), and most frequently, cruci-
ate disease. Cruciate disease can be ruled out by palpation of the stifle and evaluation of abduction
of the hip joint. If abduction is not painful, hip pathology is less likely (Figure 20.8). In juvenile
animals, the hip should be evaluated for a positive Ortolani sign (Figure 20.9).

3.2.3.2 Thoracic Limb Palpation
Digital palpation of the thoracic limb is performed as for the pelvic limb. The carpus should be
carefully evaluated for joint effusion. Namely, just below the distal end of the radius, the carpal
joint is easily palpated (Figure 13.3) and any swelling is considered abnormal. Palpation of the
distal radius and proximal humerus is extremely important due to the high incidence of primary
bone tumors in this region. The muscles surrounding the radius and ulna (with particular empha-
sis on the flexor carpi ulnaris muscle; Figure 13.10) should be carefully palpated along with the
distal aspect of the flexor tendons. The elbow should be evaluated for hyperextension, pain during
flexion, joint effusion, and medial compartment palpation (i.e. Campbell’s test; Figure 14.6).
Hyperextension of the joint is performed by pushing cranially at the level of the elbow joint while
keeping the shoulder in a consistent position (i.e. the range of motion of the shoulder should not
change when the elbow is extended, Video 14.2). Pain on flexion can be tested while the animal is
standing by simply flexing the elbow joint and evaluating for symptoms of pain and whether the
dog “moves” away and hops toward the contralateral side (Video 14.2).
The muscles surrounding the humerus should be carefully palpated and the axillary region
should be examined to assess for possible discomfort arising from the brachial plexus. Shoulder
range of motion should be evaluated ideally without performing any range of motion in the elbow,
which is difficult particularly for extension testing. Abduction of the shoulder can be estimated
during stance (Figure 15.7) but accurate abduction angle measurement requires sedation. All
regional shoulder muscles should be carefully palpated and evaluated for a pain response or spasm.
The biceps tendon can be palpated just medial to the greater tubercle (Figure 15.11). The supraspi-
natus insertion tendon is palpated at its attachment to the greater tubercle. Pain can usually be
elicited when palpating and stretching the muscle at the same time (shoulder flexion and elbow
extension). Palpation of the axillary area in older animals is advised to assess for possible brachial
plexus tumors.

3.2.3.3 Other Techniques for Lameness Detection
If the above‐listed examinations do not reveal a source of discomfort, the cause of lameness may
be secondary to muscle injury, neurologic disease, or non‐painful conditions (such as muscle con-
tractures), or because the examiner was unable to locate the painful area, or a result of the dog not
displaying a detectable pain response despite best attempts localizing the source of pain. In such
cases, several examination steps can be taken to identify the source of lameness. Specifically, evalu-
ation of the muscles including myofascial exam and stretching (Chapters 5 and 6) facilitates identi-
fication of myopathies. If no other abnormalities of a specific joint (such as decreased passive
range of motion, see Chapter 5) are identified, all muscles of the affected thoracic limb should be
thoroughly palpated and this should include passive flexibility testing. Neurologic disease that
causes subtle lameness can be difficult to diagnose on palpation; however, a full neurologic exam
may identify neurologic deficits and should therefore be performed (Chapter 4).
In some cases, although a substantial lameness associated with structural musculoskeletal
disease is observed during movement, no obvious pain response is identified during palpation.