La chirurgie de reconstruction acétabulaire dans les reprises de prothèses totales de hanches, implique de restaurer le capital osseux, d'assurer une stabilité primaire satisfaisante et de restaurer le centre de rotation anatomique de la hanche. Le but de notre étude était d'évaluer les résultats d'une technique de reconstruction acétabulaire associant des allogreffes morcelées impactées et anneau de soutien non cimenté dans les reprises de prothèse totale de hanche avec perte de substances acétabulaires de type III de l'AAOS.

Cette série rétrospective homogène comporte 34 reconstructions acétabulaires pour descellement acétabulaire aseptique avec perte de substance osseuse de type III de l'AAOS associant un anneau de soutien non-cimenté et une allogreffe morcelée impactée. L'analyse radiologique postopératoire au recul portait sur la position de l'implant acétabulaire, sa stabilité, la restauration du centre de rotation de la hanche et l'intégration de la greffe.

Le recul moyen était de 6,6 ans (3-13 ans). Sept patients ont présenté une complication nécessitant une réintervention, dont 2 avec changement d'implant acétabulaire en raison d'une infection. La survie selon Kaplan-Meier était de 91,3 % à 10 ans. Le score de Harris moyen passait de 53 points en préopératoire à 94 points au recul. Sur le plan radiologique aucune migration de cupule n'a été observée, l'intégration de la greffe était bonne dans 100 % des cas et la latéralisation de la hanche était restaurée dans 66 % des cas.

L'association d'une technique cumulant les avantages d'une cupule « press-fit » non cimentée et d'un anneau de recentrage à des greffes morcelées impactées a permis de répondre aux objectifs fixés dans notre étude : reconstruction osseuse, stabilité de la fixation et recentrage de la hanche dans les révisions acétabulaires avec perte de substance de type III de l'AAOS.

Impaction grafting can be used in cementless fixation with morsellized bone, bone graft, and hemispherical cup. The first goal of impaction grafting in revision of total hip arthroplasty is to transform segmental defects into cavitary defects and obtain a full compaction of the graft in order to restore the bone stock. The second goal is to achieve primary stability of the cup. The third goal is to restore the hip center of rotation with a cup anatomically located in the acetabulum. The aim of our study was to evaluate the results of a surgical technique with impacted morsellized bone graft and a cementless press-fit cup for the revision with defect type III according to the AAOS classification.

We performed a retrospective study including 34 hip reconstructions during revision of acetabular aseptic loosening with type III AAOS acetabular defects. All the revisions were performed in the same center by two senior surgeons. Mean age at surgery was 58 years. There were 23 women and 11 men. All reconstructions were performed with a cementless cup and a morsellized impacted bone graft. The analysis of the acetabular defects was done preoperatively according to the AAOS classification. We analyzed postoperatively and at follow-up: position and stability of the acetabular cup, restoration of the hip center and graft integration.

Mean follow-up was 6.6 years (range 3-13 years). Complications included three dislocations, two trochaanteric nonunions. Two acetabular components were revised for septic loosening. According to the Kaplan-Meier survival curves, with endpoint criteria defined as acetabular cup removal, survival was 91.3% at 10 years (95CI: 86.3-96.3). The preoperative Harris hip score was 53 points (range 26-86) and at last follow-up 94 (47-100). Concerning the subjective clinical outcome, 96% of patients were satisfied or very satisfied at last follow-up. 100% of cups were considered stable at follow-up and bone integration was good in 100%. The center of rotation was located in anatomic position mediolaterally in 66% and in the craniopodal plane in 44%.

Restoration of bone stock is one of the main goals during hip reconstruction after aseptic loosening. Clinical experience in our series has shown the reliability of the impacted morsellized bone graft allowing relocation of the center of rotation and good cup stability. Biological fixation of the cup and graft integration seems good at mid-term follow-up. The cup that we used in our series combined the advantages of a press-fit cup and those of a reinforcement ring. The combination of this type of cup with morsellized bone graft seems to be a reliable solution for restoring bone stock, relocating the hip center, and stabilizing the cup in revision total hip arthroplasty with type III acetabular defect according to the AAOS classification.