Hip dysplasia. Hereditary disease development.
Described by Snelle in America in 1935, hip dysplasia is a hereditary disease related to the development, which affects dogs and working breeds mainly surveillance.
Hip dysplasia is a malformation that affects the joints of the femoral heads with their respective acetabulum.
Various methods of evaluation of hip dysplasia based on radiographs taken dorsoventrally; the hip measurement rule allows Norberg angle measurement as well as the angle of femoral neck relative to the
shaft.
VALUATION OF THE HIP, CLASSIFICATION GUIDANCE
Different organizations and associations hip dysplasia classified in different ways but in summary containing the criteria listed below:
A. Dysplasia free. No radiographic signs of hip dysplasia
No signs of dysplasia. Correspond to an excellent articulation.
The acetabular angle according to Norberg, is> 105 o
Perfect matching of the femoral head
Narrow joint space, concentric and uniform in its entirety
Craniolateral slightly rounded edge, runs lateral to the center of the femoral head.
The cranial part of the acetabulum is smoothed and the cranio-lateral is pointy
B. A good joint without being excellent. Transition
The femoral head and the acetabulum are slightly incongruent, the joint space is slightly open, and Norberg acetabular angle is about 105 degrees.
The center of the femoral head is in internal position with respect to the dorsal edge of the acetabulum, and it and the head are congruent.
C. Slight or mild dysplasia
Femoral head with slight incongruence with their acetabular hole.
Norberg angle is between 100 ° and 105 °
Found cranio-side edge of the acetabulum, slightly flattened and the dorsal edge, can be found at the center of the medial femoral head.
There may be slight signs of irregularities or changes osteoarthrotic, both cranial acetabular margin, caudal, dorsal or on the head or neck of the femur, though, if they exist, they are pretty mild.
D. Mild or moderate dysplasia
In this type of dysplasia is a clear mismatch between the femoral head and the acetabulum, femoral subluxation.
The acetabular angle according to Norberg is somewhat greater than 90 o.
At this level, it is also characteristic flattening meet a cranio-lateral edge and / or signs of osteoarthritis.
E. Severe dysplasia
Severe dysplasia is characterized by marked signs in dysplastic hip joints, with a large overall subluxation or dislocation thereof.
The acetabular angle is less than 90 ° and a clear deformation of the femoral head and acetabular flattening cranial margin.
The signs of osteoarthritis are very marked and obvious.
Overall rating: The final opinion of the degree of dysplasia, is determined by the joint that is more altered.