HIP DYSPLASIA (HD)
Hip Dysplasia (HD) is an anomaly in the hip-joints, in which formation of the hip socket with young, growing dogs is disrupted, causing possible severe malformations.
HD is a hereditary disease, but external factors such as speed of growth, bodyweight, movement activity, muscular development and nutrition play an important role. This combination of hereditary and external factors causes faulty development of hip joints and consequent malformations. Due to these varying factors dogs with similar heredity could eventually develop different hips.
In normal hip-joints a smooth, rounded head of the femur turns in a sufficiently deep and concave acetabulum and is kept in place by a solid joint capsule and its surrounding muscles.
Because the head of the femur is able to turn in the acetabulum, the joint allows a fair amount of free movement. During turning, the head of the femur should however always articulate with the acetabulum. This solid attachment of the femoral head is not only required to ensure good functioning of the joint, but is essential in reaching a normal development of the hip-joint in young, growing dogs.
If excess tolerance occurs between the head of the femur and the acetabulum in the growing phase of young dogs, following malformations could develop:
- the attachement of the femoral head could become unsufficient or the head can even be situated (dislocated) outside the acetabulum;
- the femoral head could get flattened in stead of being smooth, rounded;
- the acetabulum could get shallow;
- anomalous bone growth could occur around the femoral head and the acetabulum due to abnormal wear of the joint
The extent to which these malformations occur can vary from minor to severe.