Hip Joint Preservation Surgery – what are the limits?

When we talk about hip preservation surgery, we are considering our ability to make a painful hip that is limiting activity into a less painful one that allows return to activity and where the alternative to allow that to happen would possibly be a hip replacement.

The common conditions that we see in young patients that lead to a painful hip are hip dysplasia and femoroacetabular impingement. We have learned a lot about these conditions over the last few years and it is clear that they are implicated in the early development of osteoarthritis of the hip. The main factor in being able to achieve success with a joint preserving procedure such as periacetabular osteotomy or hip arthroscopy and correction of FAI, is the degree of articular cartilage damage that has occurred. Once the joint space width, which is an indicator of articular cartilage thickness, on an x-ray is 2mm or less, then our ability to produce a good outcome and return to improved function is limited and a better outcome is likely to be achieved by way of a hip replacement.

We don’t understand why x-ray appearances of dysplasia and FAI produce severe symptoms and joint degeneration in some cases and not in others. It is not infrequent to see a patient with almost the identical appearance of either dysplasia or FAI in each hip but with only one hip symptomatic. We cannot predict over what period of time the other hip will or will not become symptomatic.

A common question in these circumstances is whether the other hip should be operated on to correct the shape before there are symptoms and before there is joint damage. The answer to this is absolutely not! The concern about operating on a hip that has no symptoms is that the surgery, albeit with good intentions, could result in the experience of symptoms that were not there before. We also know that some patients with apparently very compromised hips only become symptomatic very much later in life. The message is that if it is not hurting then leave it alone.