treatment of femoral neck fractures in the physically active elderly, is still an open question. The comparison of total replacement and partial hip replacement showed substantial superiority of the first approach than the latter. We can not disregard the problems that THR can lead in the elderly: more surgical time, greater blood loss, major sacrifice of bone in osteoporotic subjects. The Tribofit® acetabular system, has the objective to overcome these problems with the implantation of a single 3mm soft, pliable buffer made of polycarbonate-urethane between the large diameter metal femoral head and the subchondral bone, thus replacing the articular cartilage. The surgical technique includes the reaming of the cartilage layer, the creation of a circumferential groove and the snap-fit insertion of the buffer. The purpose of the prospective study was to evaluate the effectiveness of this approach in the treatment of femoral neck fractures in the elderly. from September 2008 to July 2010 we performed 45 implants with the Tribofit® Acetabular Buffer (Active Implants®, Memphis TN, USA). The inclusion criteria for the study were: femoral neck fracture patients over 75 years of age, physically independent before the injury, with good life expectancy, mild or absent arthritis, absence of morphological alterations of the acetabulum. The average age of these patients was 81,2 (75–89), the sex distribution was 36 females and 9 males, with 22 fractures of the left hip and 23 of the right. In all cases an uncemented straight femoral stem was implanted. We recorded per-operative blood loss and intra-per-operative problems encountered. Follow-up were performed at 1, 3, 6 and 12 months post-op with radiographic control and clinical examination. The clinical outcome was objectively measured by the Harris Hip Score, pain Visual Analogue Scale and SF-36 questionnaire.Introduction
Materials and Methods
The durable fixation of an uncemented cup is due to two major factors: the primary stability obtained by the design of the cup and the secondary fixation obtained by the features of the surface of the cup. The CSF (cancellous screws fixation) cup is an emispheric press-fit Hydroxyapatite coated cup that has 5 holes for screws. This permit to insert screws not only in the superior part of the acetabulum but also in the inferior and supero-medial. This theoretically guarantee, also in those cases in which a perfect press-fit was non achievable, a good primary fixation. This primary fixation permit the osteo-conductive function of the HA coating in order to gain secondary e more stable fixation. From january 1999 to september 2003 we per-formed130 uncemented THR with the CSF cup and the Furlong stem. In the first 100we always insert three screws. In the next 30 only in case of a non perfect-press-fit (10). The mean age was 65 years (14–80). The follow-up varying from 5 years to 6 months. The study is retrospective. At the last follow-up all implants resulted well integrated.. The formation of new trabecular bone bonding the cup was noted on the X-ray since the third month’s control. There was no complication due to the position of the screws. All patients regained full authonomy. Primary stability is mandatory in order to obtain a good secondary fixation by osteointegration. The possibility to insert additional screws in a triaxial fashion permit to obtain good primary stability. in all the cases. The screws must be inserted carefully under X-ray in order to avoid complications. Hydroxyapatite, guiding the growth of new trabecular bone bonding the cup to the pelvic bone, guarantee a good secondary fixation.
The mean way to fill bone loss, to fix loss of continuity or to correct severe dysplasia in pelvis and in the femur during replacement or revision arthroplasty is the augmentation of the bone stock by mean of bulky or morcellized bone allograft. In order to treat these problems, limiting the possible complications connected to the use of massive bone allograft (bulky or morcellized), and to simplify the surgical procedure we thought to apply in selected cases the platelet’s derived autologous growth factors (AGF), alone or added to Granular Hydroxyapatite. From january 2001 to june 2003 we have applied-autologous growth factors in 10 cases. The diagnosis was: 5 acetabula in primary THR, 2 acetabular and 1 femoral revision after THR, 1 femoral and 1tibial revision after TKR. We applied the pure AGF in 2 cases and AGF plus Granular Hydroxyapatite in 8 cases. We used emispherical, HA coated, uncemented acetabular cup plus screws (6 cases), uncemented revision cup plus screws (1 case), straight HA coated uncemented femoral stem (1 cases), semi-constrained cemented TKR prosthesis (1 cases). The mean age atoperation was 45 years (21–69). The mean follow-up time was 12,5 months (28–6). At the last follow up in all the implants there were no signs of loosening; all the graft seems to be well osteo integrated except in 1 case in which we have had fracture and partial reabsorption of the granular HA, without failure of the implant. We haven’t had any inflammatory reaction or signs of intollerance to the graft. The short term results of our experience seems to be encouraging. If these results will be confirmed in the future the application of AGF should reduce the utilization of massive bone allograft.
