The neck is the firmer structure of the proximal femur designed to spread the stresses both in compression and tension towards the metadiaphisys and the greater trochanter. Therefore femural neck preserving in total hip arthroplasty allows an optimized stresses’ distribution to obtain both an optimal integration and a subsequent better bone remodelling. The solidity of the structure and the geometric architecture with a femural neck angle of 125° guarantee the maximum primary stability, especially torsional of the stem. At last femural neck retaining allows, when requested, the revision with a richer bone-stock. For the aforementioned reasons since 1979 I proposed the femural neck preservation making a short cementless stem named Biodinamica. From 1983 to 1996 I personally implanted 498 Biodinamica prostheses with very satisfactory results showing a long term survival of the 98% (f.up 13 to 17 years). In 1996 with Ing. Keller it has been created the C.F.P. stem with the T.O.P. acetabular cup as evolution of Biodinamica system. The improvements are critical: materials have changed (from Cr-Co-Mb to Ti alloy), coating and design too. We report clinical and radiographical results of 10 years of C.F.P. implants that showed a further improvement, not only about the prosthesis’ survival, but especially regarding their quality with a 91% excellent clinical outcome. In conclusion we report the 25 years experience retaining the femural neck in hip arthroplasty with Biodinamica (498) and after C.F.P. (445) of a complessive cases of 943 arthroplasty.
The authors review the currently available treatments according to analysis of the literature. In the event of prosthetic infection, protocols available at the moment are: specific antibiotic therapy without débridement, débridement with conservation of the prosthesis, one-stage replacement of the prosthesis, débridement with definitive prosthesis removal, arthrodesis,amputation or disarticulation. The choice of the treatment must be based on the analysis of local and general factors: type of infection, clinical presentation, quality of soft tissues, prosthetic implant condition, pathogens involved, function of the knee extensor mechanisms and patient’s expectations and functional requirements. We re-evaluated the literature reports. Antibiotic therapy in infected hip prostheses yielded a successful outcome in 64% of the cases. Arthrotomic débridement in total hip prostheses showed a successful outcome in a variable percentage from 74% to 14%; in contrast, arthroscopic débridement showed a successful outcome in 100% of cases. In total knee replacement the arthrotomic débridement showed a success rate of 32.6% and arthroscopic débridement 52.2%. The mean percentage of success in replacement in one stage with antibiotic cement and preoperative antibiotic therapy was 82% in THA [1], and 71% in TKA [6]. The mean percentage of success in replacement in two stages with spacer cement and perioperative antibiotic therapy was more than 90% in THA and 91% in TKA. Prosthesis replacement in two stages showed the best rate of positive results. The antibiotic therapy was effective in all patients with positive cultures intraoperatively. Arthrotomic or arthroscopic débridement is a valid procedure, but must be performed within 2 weeks from the appearance of the symptoms. Knee arthrodesis is preferable in the presence of pathogens resistant to antibiotics and is indicated in patients with high functional requirements. The Girdlestone arthroplasty is indicated in hip treatment when antibiotic-resistant pathogens are involved. Amputation and disarticulation are indicated only in patients with a poor survival prognosis. The management of prosthetic infections represents a challenge to the entire multi-disciplinary team (i.e. specialists in microbiology, radiology, infectious diseases and orthopaedics) both in achieving a correct diagnosis (infection versus aseptic loosening) and in choosing an adequate therapeutic strategy.
