Pearls for Total Hip Arthroplasty in Patients with Hip Dysplasia
Total hip arthroplasty (THA) is a great operation for patients with hip dysplasia, offering dramatic reduction in pain and improved function. And with the new techniques and technologies available today, said Robert T. Trousdale, MD, the reconstruction is simpler, with better durability.
Speaking at Essential Hip Topics: Cradle to Grave, a 1-day meeting from ICJR and the Mid-American Orthopaedic Association, Dr. Trousdale reviewed the principles of acetabular and femoral reconstruction, illustrated by cases from his practice. Dr. Trousdale, from Mayo Clinic in Rochester, Minnesota, noted that hip dysplasia is the second most-common reason he performs THA.
In hip dysplasia, the socket is typically undeveloped but usually has adequate bone stock to place the acetabular cup. If necessary, autologous grafting can be used in patients with a large defect. On the femoral side, the femur is generally hypoplastic and malrotated, most commonly with excessive femoral anteversion. It may be altered by previous surgery.
Dr. Trousdale’s principles for reconstruction of the acetabulum in the dysplastic hip include the following:
- Uncemented fixation of the acetabular cup, with secondary screw fixation, is preferable.
- The hip center should be located as close as possible to the anatomic hip center. Dr. Trousdale will accept a bit of a high hip center in a patient with a low-riding dysplasia to maximize bone contact against the acetabular component.
- Avoid excessive anteversion of the socket: In many cases, the femur already has a fair amount of version.
- Dr. Trousdale will use a femoral head augment in a patient under age 60 who has a segmental deficiency greater than 30% to 35% to restore bone stock.
- If a graft is needed, it should be stressed; it should not overhang beyond the lateral edge of the component.
- Augment cavitary deficiencies with cancellous autograft.
- Avoid perforation of the medial wall past Köhler’s line.
On the femoral side, the surgeon should be prepared to manage severe neck anteversion. Dr. Trousdale prefers using straight conical stems that allow for unlimited version correction. Other options, he said, are cemented stems and modular components.
In a patient with more than 60° of anteversion, the surgeon should consider performing an osteotomy to optimize the trochanteric position. Failing to do so could lead to trochanteric impingement against the pelvis.
Click the image above to hear more from Dr. Trousdale about THA in patients with hip dysplasia.
Dr. Trousdale has disclosed that he receives royalties from and is a paid consultant for DePuy Synthes and that he receives royalties from Medtronic.