To this point, we have only a relatively short term followup in 32 patients with known labral lesions who have been treated by combined periacetabular osteotomy (PAO) and debridement of the damaged anterior labrum. A positive clinical history in association with pain demonstrated with the impingement test of flexion-adduction-internal rotation nearly always indicates macroscopic pathology within the anterior portion of the hip joint. Labral lesions associated with acetabular dysplasia seem more common with increasing age. Labral lesions seem to correlate with arthrosis. We suspect that uncorrected impinging lesions of the anterior rim have led to some of our early clinical failures after PAO. We feel that intra-articular treatment of certain impinging lesions may improve the clinical outcome in these patients. Correction of the pathological mechanics in the mature, dysplastic hip certainly requires restoration of stability by reorienting osteotomy. If intra-articular derangements of the anterior rim are also present, though, intra-articular surgery may also be necessary to optimize the outcome. Our early results suggest that the earlier and more complete the correction of the disordered mechanics in the dysplastic hip, the more complete and long-lasting will be both relief of clinical symptoms and preservation of a joint free from arthrosis. Anterior arthrotomy to explore the anterior rim, carried out at the time of PAO, employing the direct anterior abductor-sparing approach (DAA), seems a safe and useful adjunct in treating the mature, dysplastic hip. Much longer clinical followup and larger treatment groups will be necessary to allow firm conclusions concerning optimal treatment programs for different patient subgroups of the adult hip dysplasia syndrome.