Introduction. Progenitor cells with osteochondrogenic potential have been identified within adipose tissue. These cells present diversity of characteristics that can be explained by differences in tissue origin, isolation methods and culture conditions. Mesenchymal stem cells (MSC) have been isolated from many tissues. MSC have been shown to exhibit tissue protective and regenerative properties.

Methods. Hoffa’s fat samples were obtained from four patients (mean age 44 years), five rabbits (New Zeland aged 12 weeks) and five sheeps (Rasa aragonesa aged 22 weeks). Cells were obtained by means of enzimatic and mechanical digestion. The suspension was centrifuged and washed twice with phosphate buffered saline. The resultant pellet was resuspended and plated in culture medium (37°C, CO2 5%). Cellular markers were studied with specific monoclonal antibodies (CD13, CD44, CD49d, CD90, CD105, CD117).

Results:

Human cells: CD13+ (94–99%), CD44+ (87–99), CD49d (14–70%), CD90+ (92–99%), CD105+ (90–97%), CD 117-BD+ (2–22%).

Conclusions: MSC from human, rabbits and sheeps present differences in cellular concentration and markers.

Introduction: Use of a variable angle sliding hip screw is an interesting therapeutic option in pathological trauma of the proximal femur. It has successfully been used in cases of loosening of previously implanted hardware and non-union.

Materials and methods: In this study we present 26 cases treated consecutively in our department between 2001 and 2005. The majority of patients in this group had suffered complications in the treatment of proximal femoral fractures, including non-unions and nail cut-outs.

Results: We treated 12 male patients and 14 female patients; mean age was 72 years. Mean hospital stay was 14.3 days. The patients were examined in our consulting offices and had a minimum 6 months follow-up, with controls of their evolution at 3 and 6 months and 1 year. During the study period functional and x-ray assessments were performed. No relevant alterations were found in any of the patients; all cases resolved successfully.

Conclusions: The variable angle sliding hip screw has been successfully used in cases of severe complications in patients with proximal femur fractures. We have tried to summarize our 4 years’ experience in this study by presenting a series of different cases that went from failure of a previous osteosynthesis to other techniques applied to the fracture failure such as the use of autologous grafts to resolve non-unions. The variable angle sliding hip screw is a very useful and versatile tool in the hands of the orthopedic surgeon in certain cases where rescue surgery is necessary.