Salter’s innominate osteotomy predisposes the hip to acetabular retroversion as it hinges upon the symphysis pubis. Retroversion is a recognised cause of osteoarthritis, hip pain and clinical signs of impingement, but there is uncertainty as to whether this over cover persists with growth and development.
We reviewed the long-term follow up of twenty patients that had undergone a Salter’s osteotomy between 1985 to 1993 at The Royal Orthopaedic Hospital Birmingham or New Cross Hospital Wolverhampton. Sixteen skeletally mature patients were available for review that had previously had the pelvic osteotomy performed at a mean five years of age with a contralateral normal hip. Salter’s osteotomy had been performed for developmental dysplasia of the hip in 13 patients and for Perthes’ disease in three patients. Follow up was performed at an average age of 20 years. Outcome was assessed using the Harris Hip Score and a clinical examination for signs of impingement and by a measurement of acetabular version, on well centered pelvic radiograph.
Acetabular version was evaluated by the relationship between anterior and posterior walls of both the normal and Salter acetabulum, using radiographic templates as described by Hefti. Mean acetabular version averaged 16.9 degrees (95% CI 7.6 to 26.1) of anteversion on the Salter side and 17.6 degrees (95% CI 10.4 to 24.8) anteversion on the contralateral normal hip. There was no statistical difference between the version on operated and normal hips, paired t test (p = 0.83). Harris Hip Score averaged 85, indicating a good outcome at long-term follow up. Two patients (12%) demonstrated retroversion, however neither of these had signs of impingement on clinical examination.
After a Salter innominate osteotomy in childhood, we believe there is remodelling of acetabular version by skeletal maturity.