Hip Dysplasia Research Paper

Hip dysplasia (HD) is associated with an abnormal joint structure and laxity of the muscles, connective tissue (CT) and ligament that normally support the joint. As this joint laxity develops, the articular surfaces on the femur and in the acetabulum loose contact with each other. This separation within the joint is known as a subluxation and will cause drastic changes in both the size and shape of the articular surfaces. All dysplastic dogs are born with normal hips but the soft tissues surrounding the joint develops abnormally due to the dogs genetic make-up, and possibly other environmental factors, which is what causes the subluxation (1). The subluxation and remodeling of the hip is what leads to the symptoms that are associated with HD.

The hip joint is the attachment between the hind limb and the axial skeleton.
The pelvis girdle consists of two identical hipbones that ventrally meet at the pelvic symphysis. Dorsally they articulate with the sacrum. Each hipbone consists of the ilium, pubis and ischium that have different ossification centers. In adults, these bones are completely fused and their bodies form the cavity for the articulation with the femur, the acetabulum (8).
The acetabulum is a deep cotyloid cavity in which all three pelvic bones contribute. It is composed of the body of ilium craniolaterally, the body of ischium caudolaterally and the body of pubis medially. The acetabulum is reciprocal to the head of femur, with which it forms the spheroidal hip joint. The acetabular cavity consists of the peripheral articular lunate surface and the non-articular acetabular fossa in the center. The articular surface is enlarged by a fibrocartilaginous articular labrum. The lunate surface is crescentic and medially is has the acetabular notch through which the intrascapular ligament of the femoral head emerge and joins the femoral head to the acetabular fossa.