Page 65 - Canine Lameness

3.2 The Orthopedic Examination 37

Long bone palpation is important not only in geriatric dogs (to detect potential primary bone
tumors), but also in any dog because other diseases, such as panosteitis (in younger patients) or
fractures, can be present.
Muscle atrophy is an important indicator of pathology in the affected limb. Neurogenic atrophy is
generally severe and can develop in as little as a week, while disuse atrophy from orthopedic
disease is generally less severe and develops over multiple weeks. Notably, a severely atrophied
leg may not necessarily be the most impaired limb. For example, a dog with chronic left cruciate
disease may acutely rupture the right cruciate ligament which would result in a severe right
pelvic limb lameness but left‐sided muscle atrophy. Measurement of limb circumference to
assess atrophy is subjective and generally performed by palpation or use of a Gulick tape meas-
ure (please refer to Chapter 5 for further details).
Joint crepitus is defined as a grinding or grating sensation or sound that is caused by severe degen-
eration of the joint or intra‐articular fractures. As such, joint disease has to be severe and there-
fore should be radiographically detectable. It is not uncommon to palpate a popping sensation
during elbow flexion‐extension, which can be observed in dogs without radiographic changes.
This should be differentiated from joint crepitus since it is likely due to flexor tendons passing
over the medial epicondyle. Similarly, shoulder abduction may cause a popping noise which is
likely due to cavitation (i.e. the formation of gas bubbles within the joint cavity). Clicking or
popping of tendons over bony prominences and cavitation has been described in people
(Unsworth et al. 1971) but these concepts have not yet been confirmed in dogs. Regardless, the
term (joint) crepitus should be reserved for animals with substantial joint disease.
Specific tests (e.g. testing for cranial drawer, goniometry, Ortolani maneuver, etc.) are crucial to
determine the diagnosis for various conditions. These are described in the individual region
chapters.

3.2.3.1 Pelvic Limb Palpation
The palpation starts with observation and palpation of the distal limb: flexion and extension of all
digits together should be performed to assess if a problem is present, as indicated by signs of dis-
comfort or abnormal anatomy. If an impairment is detected, further evaluation of each individual
digit is performed to assess potential collateral ligament injuries or other pathology. The nails,
webbing, and pads should also be examined for any injuries, foreign bodies, or masses. The sesa-
moid bones are located just distal to the tarsal pad (Figure 12.7) and should be palpated carefully
for swelling and pain. Swelling of the tarsal joint is best felt by palpating the area just proximal to
and on each side of the calcaneus. Because long and short collateral ligaments stabilize the tarsus,
assessment of this joint must include applying varus and valgus stress in flexion and extension.
The insertion of the common calcanean tendon should be evaluated carefully for any swelling or
pain and followed proximally to the musculotendinous junction. The muscles surrounding the
tibia should also be palpated. The stifle should be evaluated for signs of cruciate ligament disease
or patellar luxation. Frequent signs of cruciate disease include joint effusion, medial buttress, pain
on hyperextension, positive drawer (Figure 19.7) and tibial compression (Figure 19.8) test, and a
meniscal click. Medial patellar luxation is diagnosed by extending the stifle while rotating the limb
internally. The thumb of one hand is placed on the lateral aspect of the patella, and the patella is
pushed medially out of the femoropatellar joint. The opposite (i.e. stifle flexion and external rota-
tion while pushing the patella laterally) is performed for lateral patellar luxations. The collateral
ligaments of the stifle should also be evaluated by applying medial and lateral stress in extension.
The tibial and femoral diaphysis should be carefully palpated for any signs of pain to assess for
bone pathology. The muscle groups around the femur should be palpated as for other areas.