during total hip replacement there is acetabular deficiency either cavitary or segmental what about biological reconstruction in such cases.
Thank you for this interesting question. Biological reconstruction of the acetabulum is one of the first methods used mainly for dysplastic hips. It is known the Harris technique when he was using the head as graft at the superior part of the socket to create "roof" and also the cotyloplasty used by Hartophylakides when he osteotomised the floor of the acetabulum, pushing it in, creating an extension of the roof and used bone reamings to augment the floor and the roof. In protrusion acetabuli also the part of the head was used as graft at the floor of the socket to help the lateralisation of the total hip (Semi-circular, semilunar or "mexican hat" grafts). All grafts have good outcome, although in literature is know that the Harris technique graft had increased risk of avascular necrosis and absorption. This was at those where there was small contact area and the graft was long trying to create enough lateral support.
In cases of hip revision due to lack of autograft, the used of allograft or xenograft was used (bovine, coral ect). The use mainly of bovine dry grafts increased the infection rate. Coral at all times was visible and possibly it was never remodelled, although there is literature that says the opposite. In recent years due to lack of allografts (new regulation for bone banks which increased the cost) the metal augmentation blocks came to help (trabecular metal etc). Autograft when possible gives better results but the stabilisation, fixation, contact surface and size of it (as this will determine the revascularisation) are the factors that will determine the success.
Hope you find this helpful
I agree entirely with the post of George and his considerations. In my experience the Harris technique is quite good, although Prof. Harris himself presented some limitations in a later publication.
On the other hand, I would like to draw your attention to the role of Chiari pelvic osteotomy. In my opinion it is a very useful augmentation step in early stages of symptomatic displastic hips. It should not be underestimated, especially in young patients, and it makes the positioning of the cup more safe at a later stage (sometimes after 10 or more years) when THR is indicated.
What I usually love to do, if possible, in case of cavitary/segmentary acetabular defects, is to fill it with homologous bone chips prepared from femoral heads coming from the local bone bank. Then I do reshape the cavity to the proper pattern by compressing the graft witch a counter-turning hemispherical reamer. Recovering the bone inside it and regrafting it is commonly a good idea before increasing the size of the reamer in order to obtain adequate Equatorial fit. A trabecular surface, multi hole cup would be the ideal complement to achieve a proper primary stability.
thank you very much my professors, Panayot Tanchev, George Zafiropoulos ,· Michele Francesco Surace
Fully agree with all these posts. These techniques have my preference too especially the one described by
(sorry) by Michele Francesco Surace even for complex revisions requiring extended grafting (up to Paprosky 3B). There is certainly no more place for cementing...
An autologous or homologous repair of the acetabular roof/cavity in combination with an endoprotetic implant is giving good results. First method works only if you have a bone bank of preferrable femoral heads, which can be srewed or morcellized. The bone mostly is integrated very well.
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