Survivorship and Clinical Outcome of the Minimally Invasive Uniglide Medial Fixed Bearing, All-polyethylene Tibia, Unicompartmental Knee Arthroplasty at a Mean Follow-up of 7.3 Years

Background: Medial UKA performed in England and Wales represents 7 to 11% of all knee arthroplasty procedures, and is most commonly performed using mobile-bearing designs. Fixed bearing eliminates the risk of bearing dislocation, however some studies have shown higher revision rates for all-polyethylene tibial components compared to those that utilize metal-backed implants. The aim of the study is to analyse survivorship and maximum 8-year clinical outcome of medial fixed bearing, Uniglide unicompartmental knee arthroplasty performed using an all-polyethylene tibial component with a minimal invasive approach. Methods: Between 2002 and 2009, 270 medial fixed UKAs were performed in our unit. Patients were reviewed pre-operatively, 5 and 8 years post-operatively. Clinical and radiographic reviews were carried out. Patients’ outcome scores (Oxford, WOMAC and American Knee Score) were documented in our database and analysed. Results: Survival and clinical outcome data of 236 knees with a mean 7.3 years follow-up are reported. Every patient with less than 4.93 years follow-up underwent a revision. The patients’ average age at the time of surgery was 69.5 years. The American Knee Society Pain and Function scores, the Oxford Knee Score and the WOMAC score all improved significantly. The 5 years survival rate was 94.1% with implant revision surgery as an end point. The estimated 10 years survival rate is 91.3%. 14 patients were revised before the 5 year follow-up. Conclusion: Fixed bearing Uniglide UKA with an all-polyethylene tibial component is a valuable tool in the management of a medial compartment osteoarthritis, affording good short term survivorship

A reassessment of Kelmayisaurus petrolicus, a large theropod dinosaur from the Early Cretaceous of China

The Early Cretaceous fossil record of large−bodied theropods from Asia is poor, hindering comparison of Asian predatory dinosaur faunas with those from other continents. One of the few large Asian theropod specimens from this interval is a partial skull (maxilla and dentary) from the Lianmugin Formation (?Valanginian–Albian), the holotype of Kelmayisaurus petrolicus. Most authors have either considered this specimen as an indeterminate basal tetanuran or a nomen dubium. Weredescribe K. petrolicus and note that it possesses a single autapomorphy (a deep accessory groove on the lateral surface of the anterior dentary), as well as a unique combination of characters that differentiates it from other theropods, affirming its validity. A phylogenetic analysis recovers K. petrolicus as a basal carcharodontosaurid, which is supported by various features: very deep interdental plates (a carcharodontosaurid synapomorphy), fused interdental plates (present in carchardontosaurids and a limited number of other theropods), and the absence of diagnostic features of other clades of large−bodied theropods such as abelisaurids, megalosauroids, and coelurosaurs. As such, Kelmayisaurus is the second known carcharodontosaurid from Asia, and further evidence that this clade represented a global radiation of large−bodied predators during the Early–mid Cretaceous

Neutron reflection from a dimyristoylphosphatidylcholine monolayer adsorbed on a hydrophobised silicon support

AbstractNeutron specular reflection has been used to study the structure of a monolayer of dimyristoylphosphatidylcholine (DMPC) deposited using the Langmuir-Blodgett technique onto a silicon oxide substrate. A self-assembled monolayer of octadecyltrichlorosilane with a deuterated alkyl chain (d-OTS) had been previously bonded onto this silicon oxide substrate which rendered it hydrophobic. In the system under study, the alkyl chains of the phospholipid were found to penetrate extensively into the d-OTS layer with the mixed chain region (d-OTS and DMPC) having a total thickness of 30.5 Å. This mixed region was divided into two halves for analysis; the ‘lower half’ (nearest to the substrate surface) was found to comprise anchored d-OTS chains mixed with the lipid chains in the volume ratio approx. 0.60:0.35. The corresponding volume ratio in the ‘upper half’ of this region was determined to be approx. 0.50:0.40. The thicknesses of these regions were found to be 17.9 Å (incorporating approx. 6% solvent) and 12.6 Å (incorporating approx. 9% solvent) for the lower and upper halves respectively. The DMPC head groups were found to be confined to the most external layer (furthest away from the silicon substrate). This layer was found to have a thickness of 9.4 Å and included a small fraction of the lipid alkyl chains with approx. 47% solvent