Scroll to top


Dysplastic Hip and Deformity

The term hip dysplasia describes undesirable developments as the result of congential or developmental malformation. Repeatedly the abnormity is found at the acetabulum (articular cavity) in newborns. It is characteristic for this deformity that the femoral head is not overlaid sufficiently (Figure 1). If there is a diminished roofing of the femoral head, it is possible that ,due to extensive strain on the smaller acetabulum, a premature osteoathritis is formed. This could lead to no other option than a endoprosthesis in younger years. In pronounced cases a hip joint luxation can occur. In this case the femoral head is outside the acetabulum and creates a compensation socket which is located at the pelvis edge.

Figure 1: Dysplastic Hip: diminished femoral head roofing through the acetabulum (CE-angle 21°)

If a hip dysplacia is presence load-dependend pain in the affected join can appear which leads the patient to a doctor’s visit. At an early stage, with a small cartilage damage, there is the option for the reduction of wear by the use of a three-dimensional pelvic correction.
The Peri-Acetabular Pelvic Osteotomy (PAO) in accordance with Ganz is one possible therapy of hip dysplasia . With this technique the acetabulum and the bone around it are detached from the pelvis before they get reconnected at the correct position. The femoral head will then be overlaid by the actetabulum normally and physiological, respectively (Figure 2).

Figure 2: Dysplastic Hip: diminished femoral head roofing through the acetabulum. After an Acetabular Pelvic Osteotomy (PAO) an adequate roofing could be achieved.

In case of a simultaneous malpositioning of the femoral neck a correction at this area also can be performed (e.g. DVO - Derotation-Variation-Osteotomy), in order to reach the optimal femoral head position inside the acetabulum. Clinical and further diagnostic measures play a stering role at the diagnosis: For example, x-rays of the pelvis in combination with an MRI of the hip help to make the correct diagnosis.
As a follow-up treatment following the corrective operation it is important to mobilize the joint. As a general rule the mobilization shall happen due partial weight-bearing for at least 6-9 months. After this period of time a prompt increased load bearing in essential. What is also important in connection with a good outcome is the maintainance by experienced physiotherapists.