Abstract
Introduction: A criticism of innominate osteotomy is that it causes relative acetabular retroversion, predisposing to osteoarthritis. This study was designed to address this hypothesis.
Materials and Methods: We had access to radiographs of 30 patients that had undergone open reduction and innominate osteotomy for late presenting developmental hip dislocation. The patients are now middle-aged and formed part of a previously reported study on the long term outcome of this protocol. Standardised, well-centered anteroposterior standing hip radiographs had been obtained. We used the validated method of Hefti (1995) to measure anterior and posterior acetabular coverage and contact area. All measurements were made by a single independent investigator.
Results: 10 operated hips had advanced osteoarthritis which made it impossible to identify acetabular landmarks. 26 hips were readable despite signs of mild to moderate osteoarthritis in some (Group A). 20 contra-lateral hips without DDH which appeared radiographically normal formed control group B.
Discussion: We were unable to assess operated hips which had gone on to replacement or severe osteoarthritis. This is a flaw as those hips with better radiographs have been selected out for study. Nonetheless this was a unique opportunity to assess the effect of innominate osteotomy on acetabular development in good numbers of hips with a variety of evolved outcomes.
Conclusion: Acetabular coverage and load area in hips with a good outcome after innominate osteotomy with open reduction were not different to a control group of radiographically normal hips without previous DDH. Innominate osteotomy before the age of 5 years has the potential to facilitate, or at least not prevent, normal acetabular development and version.
Correspondence should be addressed to BSCOS c/o BOA, at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London, WC2A 3PE, England.
