Abstract
For the surgical approach a trochanteric osteotomy should be utilised if lengthening is to be carried out. The leg can be lengthened up to 4 cm but the nerve should be monitored by exploration, a wake up test, or electrical monitoring.
Bone grafting for reconstruction of the dysplastic acetabulum in total hip arthroplasty has certain distinct advantages. It provides bone support for the acetabular prosthesis at the correct or near correct level. It restores anatomy and corrects leg lengths. It restores bone stock for future surgery. The alternatives, the high hip center, or medialisation are acceptable if adequate bone stock is available and leg lengths are not a problem (i.e. bilateral disease). The potential problem of these two techniques is that they do not restore bone stock for future surgery.
Cemented or uncemented components can be used. Small straight stems must be available in order to fit the dysplastic femur. Most implant designs carry CDH components. The dysplastic femur is not only small in diameter, but also excessively anteverted. If an anatomic stem is used it will be too anteverted. A straight narrow stem allows the surgeon to position the stem correctly.
Between May of 1982 and May of 1994, 67 hips in 58 patients underwent total hip replacement for congenital dislocation with the use of bulk autograft to augment the acetabulum. The average follow-up was 10 years. The revision rate for the cups was 16% (11 hips), and for the stem 6% (four hips). The clinical and radiographic failure rate for the 67 hips was 25% (12 revised, one waiting revision, and four definitely loose). The Kaplan-Meier survivorship for the cups at 14 years was 78%, and the stem 85%. There were three graft nonunions all of which required revision. Resorption of over one-third occurred in 10% of grafts (seven grafts), with four requiring further revision, but only one requiring another structural graft.
The abstracts were prepared by Mrs Dorothy L. Granchi, Course Coordinator. Correspondence should be addressed to her at PMB 295, 8000 Plaza Boulevard, Mentor, Ohio 44060, USA.
