ORTHOPAEDICS
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radiograph (Figure 2a). Compare this with the position of
the second radiograph, which also has effusion but the
tibia is not displaced into a cranial position (Figure 2b).
Another consistent finding is osteophyte or enthesiophyte formation in the region of femoral trochlear ridges
and tibial plateau and at the base and apex of the patella.
HIP DYSPLASIA
Hip dysplasia causes joint inflammation and secondary
osteoarthritis, which lead to variable degrees of pain.
Clinical signs can vary from slight discomfort to severe
acute or chronic pain. Although the disease onset has a
linear progression over time, it can be divided into two
forms.
Figure 3b: Severe hip dysplasia is more easily seen and felt on physical examination. Radiographs confirm arthritic changes and help
planning for surgery.
The chronic form of hip dysplasia has a highly variable
onset of clinical signs in middle-aged to senior dogs.
Figure 3a: Mild hip dysplasia often has incongruence, acetabular
sclerosis and a thickened Morgan's line where the joint capsule inserts along the femoral neck.
The juvenile form typically affects dogs between 5 and 12
months of age. Affected dogs may present with unilateral
or bilateral hindlimb lameness or pain on hip extension.
Affected dogs may be bunny hopping at presentation,
have difficulty rising after rest, exhibit exercise intolerance, or seem reluctant to walk, run, jump or climb stairs.
These clinical signs are the result of joint laxity and resultant instability and inflammation.
Pain is most often related to degenerative joint disease
and has a more severe presentation. Clinical signs are
similar to the juvenile form. Pain is elicited most notably during hip extension. Patients tend to off load their
hip joints by shifting weight forward onto their thoracic
limbs. Because of weight shifting over a long period of
time, muscle atrophy of the hindlimbs is common. In
large dogs, you can often see muscular hypertrophy of
the forelimbs as a result of the dogs’ chronically hauling
themselves up by their forelimbs.
Imaging
As the disease progresses, crepitus can be palpated with
range of motion manipulation. An examination while the
patient is sedated, followed by orthogonal radiography
will further support the diagnosis of hip dysplasia. While
the more chronic cases are much easier to diagnose on
radiographs and physical examination (Figures 3a & 3b),
If you examine the patient and still have doubts about the diagnosis,
sedate the dog and repeat your entire examination.
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