No abstract

BackgroundTransfusion with red blood cells (RBC) may be needed during hip revision surgery but the appropriate haemoglobin concentration (Hb) threshold for transfusion has not been well established. We hypothesized that a higher transfusion threshold would improve ambulation after hip revision surgery.MethodsThe trial was registered at Clinicaltrials.gov ( NCT00906295). Sixty-six patients aged 18 years or older undergoing hip revision surgery were randomized to receive RBC at a Hb threshold of either 7.3 g/dL (restrictive group) or 8.9 g/dL (liberal group). Postoperative ambulation was assessed using Timed Up and Go-test (TUG) and ability to walk was also assessed daily by a physiotherapist blinded to the allocation.ResultsFifty-three patients were able to perform the TUG and included in the analysis. The TUG could be completed in a median of 36 sec vs. 30 sec in the restrictive group and the liberal group, respectively (P = 0.02). The mean difference in TUG was 14.5 sec (95% CI 2.8-26.2 sec). No difference was found in the day patients could perform TUG or walk 10 meters. The Hb at the day of testing was 10.2 g/dL in the restrictive group and 9.9 g/dL in the liberal group. Only 26 patients received RBC.ConclusionsA Hb transfusion threshold of 8.9 g/dL was associated with a statistically significantly faster TUG after hip revision surgery compared to a threshold of 7.3 g/dL but the clinical importance is questionable and the groups did not differ in Hb at the time of testing.

Our results, with almost 12 years survival data, are comparable with the literature. PAO is considered as an effective treatment for young adults with painful hip dysplasia, especially when preoperative criteria for conversion to THA are highlighted.

We investigated the effects of polymerization heat and toxicity of polymethylmetacrylate bone cement in the canine tibial diaphysis. Heat was studied by filling the tibias with either bone cement or bone wax contained in a monomer tight membrane pouch. Toxicity was studied by filling both tibias with cement, with the control side contained in the membrane pouch. Bone blood perfusion was measured by microsphere technic, and bone remodeling by 99mTc-methylene diphosphonate uptake and by histologic technique. In bone exposed to the combination of polymerization heat and monomer, both perfusion and remodeling were impaired. We did not find any effects of polymerization heat alone. We conclude that hot toxic chemicals from bone cement during polymerization may inhibit bone blood perfusion and remodeling, whereas heat alone seems to be of minor importance for the regenerative processes in cemented diaphyseal bone.