Ceramic on ceramic cementless total hip arthroplasty in arthritis following congenital hip disease: an algorithm of the surgical treatment

The prevalence of Congenital Hip Disease (CDH) in Europe is ranging between 2% and 3%. There are, though, 3 regions where it reaches 4-5%: Bohemia (Cech Republic), Upper Palatinate (Germany) and Emilia Romagna (Italy). The Rizzoli Institute of Bologna, capital of Emilia Romagna, is traditionally the Orthopaedic Hospital treating these large number of patients of northern Italy. Thus, in a previous series of cementless Hip implants [1] published by us in 1994 the prevalence of CDH arthritis was 32%, that is one patient out of three undergoing THA in our department showed some degree of CDH, from minimal alteration to congenital iliac dislocation. In these cases, Total Hip Replacement for degenerative arthritis can be technically difficult. In fact, the Hip anatomy can be severely altered and component placement (especially the cup) is always complicate.Based on our experience, we have classified our cases in 3 groups according to their anatomo – pathologic picture which has determined the indication to a specific surgical procedure: Group A, B and C. First of all, we must say that femoral anatomical features, differently from acetabulum, tend not to vary with the severity of the disease and are fairly uniform. The main features of Dysplastic arthritis of the hip are: 1) FEMUR a straight and narrow femoral canal with a more or less severe anteversion (usually about 20°-25°; that is around 10° more than normal). Regarding to length, in our experience, dysplasic femora are generally hypoplasic (and then shorter than normal)) or normal, rarely hyper-plasic. With these features a straight stem is necessary, cemented or (better) cementless allowing the correction of the anteverted neck. 2) ACETABULUM = we have maintained the 3 groups of Hartofilakidis [2] with more attention to the acetabular morphology, designing an algoritm of the surgical treatment. A) Group A ("DYSPLASIA" of HARTOFILAKIDIS) (Fig. 1a-d) the acetabulum is small, the antero-lateral wall is deficient, sometimes absent, the medial wall is usually not too thick creating problems for placing the cup. 237 Tricks and tips: how to manage the implantation of ceramic implants