Patient restrictions following total hip arthroplasty: A national survey.

In this prospective nation-wide web based survey we describe the current practice regarding patient restrictions following total hip arthroplasty. A web-based survey involving 20 items was developed and tested prior to administration. The questionnaire included general information, type of restrictions, specification and duration of restrictions. The target population consisted of all orthopaedic surgeons registered with the Dutch Orthopaedic Association working at one of the 94 orthopaedic departments in the Netherlands. The response rate of the orthopaedic departments was 78% (n=74). The majority of orthopaedic departments use patient restrictions following THA. Restrictions were used with different rates per type of surgical approach: anterior (69%), anterolateral (100%), straight lateral (94%) and posterolateral (93%). The duration of these restrictions is generally six weeks. Patient restrictions following THA are current practice, regardless of the surgical approach.

Development of novel membranes for blood purification therapies based on copolymers of N-vinylpyrrolidone and n-butylmethacrylate.

Developments in membrane based blood purification therapies often come with longer treatment times and therefore longer blood-material contact, which requires long-term membrane biocompatibility. In this study, we develop for the first time membranes for blood purification using the material SlipSkin™, which is a copolymer, made from N-vinylpyrrolidone (NVP) and butylmethacrylate (BMA). Specific attention is focused on understanding the mechanism of pore formation and the tailoring of the membrane mechanical and transport properties to obtain the optimal membrane for blood purification therapies. Polymer composition, solvent type and solvent evaporation time influence membrane morphology and membranes with sieving properties of cascade filters in plasma fractionation applications are developed. The new membranes have very good blood compatibility properties; in fact compared to benchmark flat membranes currently used in the clinic, they have lower platelet adhesion while all other properties (contact activation, thrombogenicity, leukocyte adhesion, hemolysis and complement activation) are also very good and comparable to the benchmarks.

Optimal perfusion of an intact ovary as a prerequisite for successful ovarian cryopreservation.

BACKGROUND: Cryopreservation and subsequent reimplantation of intact ovaries from cancer patients, offers potentially the best prognosis for restoring fertility after sterilizing cancer treatment. We used bovine ovaries as a model system to explore the perfusion procedure that is required for cryopreservation of intact ovaries. METHODS: The arteria ovarica was cannuled, and ovaries were flushed with Indian ink for 5 min. RESULTS: Successful perfusion of blood vessels was immediately visible macroscopically by a grey to black discoloration of the ovary and was confirmed microscopically, by examining tissue sections. There was no correlation between the time interval from removal of the ovary to the start of the perfusion, and success of perfusion. We determined the percentage of Indian ink-perfused vessels and scored blood vessels in four different size classes. The percentage of perfused vessels increased with an increase in vessel size. In a limited set of preliminary experiments with human ovaries, comparable results were obtained. CONCLUSIONS: Our results show that bovine ovaries are a suitable and adequate model system for optimizing the cryopreservation of human ovaries. As bovine are at least of comparable size to human ovaries, we expect that our results can be extrapolated to the human situation.