Different pelvic osteotomies and various shelf procedures are used for the operative treatment of hip dysplasia. Slotted acetabular augmentation (SAA) is a well-established technique for the treatment of children and adolescents with hip dysplasia. It has not been widely accepted for treating hip dysplasia in adults although good outcomes have been reported with other augmentation techniques in adults.
Since 1997, SAA has been used for the prevention of hip arthrosis in 14 dysplastic hips in 12 female patients. The median age at operation was 38.5 (17-42) years; the median follow-up period was 4 (1-8) years. The patients were evaluated on the basis of radiographic, biomechanical and clinical data prior to surgery and at follow-up.
The median centre-edge angle of Wiberg increased from 9 degrees (1-26) before the operation to 43 degrees (31-55) at the latest follow-up (P < 0.001). The median peak stress on the weight-bearing area of the hip, calculated mathematically, was reduced from 14.9 (6.3-28-1) MPa prior to the operation to 4.1 (3-6.1) MPa at the latest follow-up (P < 0.001); the median Harris Hip Score increased from 60 (45-98) points preoperatively to 93 (49-100) points at the follow-up (P < 0.001). There was no difference between the preoperative and follow-up hip joint-space width (P = 0.2).
There were no postoperative complications. In our series, the procedure has proved reliable and safe. Its advantages include symptomatic pain relief, adequate acetabular roof coverage and reduced peak stress on the weight bearing area of the hip. It can be used to postpone the development of hip arthrosis in adults with acetabular dysplasia.