The Hipstar cementless system (Stryker) is a straight, wedge-shaped with a rectangular cross-section, titaniumalloy (TMZF) femoral component. This particular titaniumalloy (titanium, molybdeno, zirconium and iron) makes the stem 20% more resistant and less elastic than TiAlV alloy. The advantages are: a thinner neck with an equal resistant, an increase of range of motion, a reduction of impingement.

We examined 100 consecutive primary THRs between January 2002 and March 2004. The mean age was 69,9. Preoperative evaluation included a physical and radiographic examination. The acetabular component was the Trident cup (Stryker). Clinically, all the 100 hips were evaluated according to the scoring system of Harris. A patient’s evaluation test (WOMAC test) was also performed. At the time of the latest follow-up, standardized antero-posterior and axial radiographs of the pelvis and hip were made and evaluated according to Engh radiographic score. The median duration of follow-up was 24 months.

The median post-operative Harris Hip Score for 100 hips was 90.5. The observed mean value of WOMAC test score was 5,11. At the time of the latest follow-up, there was a bony incorporation of all components. We have had 2 cases of dislocation. At the latest follow-up no evidences of infection are present.

Loss of bone stock resulting from wear particle-induced osteolysis may compromise the stability and osteoin-tegration of arthroplasty implants. Usually allogeneic corticocancellous bone is used around an implant to fill the defects, but because of the safety and availability of these grafts, the use of synthetic substitute of bone is becoming everyday frequently. BoneSave™ is an osteo-conductive biomaterial prevalently used in reconstructive surgery but it can be used to fill every bone defects or in traumatology like adjuvant of an osteosynthesis. The particles of BoneSave™ (2–4 mm or 4–6 mm) are made of tricalcium phosphate 80% and hydroxyapatite 20%, they have a superficial porosity of 50% (range 10–400 mm). Usually the osteointegration happens after 2–3 years. Recently studies have described that the mixture of 80% TCP/20% HA with human mesenchymal stem cells induced bone formation in vivo faster than the other formulations of the same elements, In vitro studies also demonstrated the expression of osteocalcin. The mixture of TCP/HA with bone-marrow aspiration could be useful if human stem cells are not available. Orthopaedic and traumatology cases will be shown where the use of Bone-Save™ has lead to good clinical and radiological results after a follow-up of 24 months.