Non-prosthetic surgical treatment of hip dysplasia (see hip dysplasia) has two goals: to correct the dysplasia (either acetabular or femoral) and to treat the joint injuries resulting from these dysplastic changes and thus improve the biomechanics of the hip to try to prevent the development of secondary arthrosis.
Correcting dysplasia involves altering the shape of the joint to make it more congruent and therefore more stable. The way we can change the shape and orientation of both the acetabulum and the femur is with osteotomies (bone cuts). These (osteotomies) create free fragments or “bone blocks” that can be mobilized and placed in the desired position (to correct dysplasia) and then fixed with plates and screws. Once very popular, non-pediatric (post-adolescence) pelvic and femoral osteotomies have become less and less frequent, mainly due to the success and technical evolution of hip prosthesis (performed at earlier and earlier ages and with greater longevity) – see hip prosthesis.
Another crucial and limiting factor of osteotomies is the severity of the articular lesion, namely of the cartilage. The secret of the success and longevity of osteotomies (conversion rate of an osteotomy into a hip prosthesis in the future) is closely related to early diagnosis of dysplasia and articular lesions. In addition, pelvic and femoral osteotomies are complex surgeries with long recovery times and potential risks (vascular and nerve damage), so they should be performed by hip and hip specialists.
There are several pelvic osteotomies described over the years (some are no longer used) but the osteotomy described in 1984 by Professor Reinhold Ganz in Bern, Switzerland, and therefore called Bernese osteotomy or periacetabular osteotomy (PAO) is currently the gold standard (reference procedure) for the treatment of acetabular dysplasias. Not only for its versatility and possibilities in the correction of dysplasia (acetabular coverage, version and medialization) but also for maintaining the integrity of the posterior column of the acetabulum, which allows for early deambulation and rehabilitation, which is fundamental for removing the morbidity of this surgical procedure. Currently with over 30 years of history, it presents in the “best hands” a survival rate (not conversion to prosthesis) of 60% at 20 years and 30% at 30 years (published in 2016). The surgery can be performed by different approaches (ilio-inguinal, Soballe, Smith-Peterson) being the ilio-inguinal the route initially described. Four osteotomies (bone cuts) and a controlled fracture around the acetabulum are performed. The loose fragment is then mobilized to the desired position and fixed with screws.
Regarding femoral osteotomies, they are essentially femoral varus-desrotation surgeries (therefore called varus-desrotational osteotomy – VDO) with the aim of “bringing” the femoral head to point to the “center” of the acetabular cavity. They may be performed isolatedly or in association with acetabular osteotomies and are much less technically complex than these. The approach is lateral to the hip and directly “above” the site where normally only one osteotomy is made in the intertrochanteric region (between the greater and lesser trochanters). After the correction is done, the osteotomy is fixed with a blade plate and screws specific for these situations.
With the success of early screening programmes for hip dysplasia and the technical evolution that hip prostheses have undergone in recent years, pelvic and femoral osteotomies have become less and less frequent. However, they still have their place in the treatment of a specific group of patients with early detection of symptomatic non-arthritic dysplastic disease, as in these cases they can not only treat the dysplasia and its symptoms but also prevent the onset of secondary hip arthrosis.
