ABSTRACT
Purpose@#The current study aimed to investigate the morphology of the true acetabulum in developmental dysplasia of the hip (DDH) with high dislocation. A secondary was to evaluate the acetabular cup placement in patients with high dislocation who were treated with total hip arthroplasty (THA). @*Materials and Methods@#Using a retrospective design, 23 hips with DDH with high dislocation in patients who were treated with THA were included in this study. We measured the depth, width and thickness of the anterior and posterior walls of the original acetabulum using preoperative computed tomography images and investigated the cup size applied in these cases. @*Results@#The mean depth and width of the acetabulum was 18.4 and 16.2 mm proximal end, 18.4 and 24.3 mm in the middle, and 15.8 and 27.6 mm at the distal part. Mean thickness of the anterior and posterior walls was 10.9 and 23.9 mm at the proximal end, 10.3 and 22.2 mm in the middle, and 10.9 and 22.7 mm at the distal part. A 42-mm cup was using in one hip, a 46-mm cup in three hips, a 48-mm cup in 13 hips, and a 50-mm cup in six hips. @*Conclusion@#In patients with Crowe IV DDH, the morphology of the acetabulum comprises a triangle that broadens from proximal to distal points, with a relatively thick posterior wall. Reaming the acetabulum posteriorly and inferiorly may enable the placement of a relatively larger cup to achieve stable fixation.
ABSTRACT
In Japan, hip joint degenerative diseases are based on acetabular dysplasia and the treatment strategy has been focused primarily on how to maintain the hip joint function and how to achieve pain relief. We employed total hip arthroplasty (THA) to treat end-stage OA of the hip joint. There are many possible complications in THA including infection, dislocation and nerve palsy. Especially in patients with Crowe IV dislocation, THA should be accompanied by simultaneous subtrochanteric shortening osteotomy to prevent sciatic nerve palsy. There is concern that the small metal head and posterior approach without re-attachment of posterior soft tissue commonly used in THA may be susceptible to postoperative dislocation. To avoid this scenario, we developed a modified less invasive total hip arthroplasty surgical approach that uses the anterolateral approach of the modified Watson-Jones approach. By using this approach, the risk of postoperative dislocation can be greatly reduced due to the intact posterior stabilizing soft tissue of the hip joint. Recently, a new concept in hip pathology describing femoroacetabular impingement (FAI) including retroversion of the acetabulum was proposed by Professor Ganz in 2003. Patients with acetabular dysplasia were also assumed to have acetabular retroversion. In patients with acetabular dysplasia to prevent further pathology of the hip joint, we developed a reorientation rotational acetabular osteotomy using a navigation system to obtain accurate direction and alignment in the reorientated hip joint. Orthopedic surgeons and rehabilitation doctors need to understand each other well in their respective fields of pathology and treatment strategy to ensure the optimal treatment of motor diseases.