Background: Hip fractures are common injuries that result in blood loss and frequently require the transfusion of blood products. We sought to identify risk factors leading to increased blood transfusion in patients presenting with hip fractures, especially those factors that are modifiable. Methods:We retrospectively reviewed the cases of all patients who had fixation of their hip fractures between October 2005 and February 2010. The need for transfusion was correlated with potential risk factors, including age, sex, preoperative hemoglobin, fracture type, fixation method and more.Results: A total of 835 patients had fixation of their hip fractures during the study period; 631 met the inclusion criteria and 249 of them (39.5%) were transfused. We found an association between need for blood transfusion and female sex (p = 0.018), lower preoperative hemoglobin (p < 0.001), fracture type (p < 0.001) and fixation method (p < 0.001). Compared with femoral neck fractures, there was a 2.37 times greater risk of blood transfusion in patients with intertrochanteric fractures (p < 0.001) and a 4.03 times greater risk in those with subtrochanteric fractures (p < 0.001). Dynamic hip screw (DHS) fixation decreased the risk of transfusion by about half compared with intramedullary nail or hemiarthroplasty. We found no association with age, delay to operation (p = 0.17) or duration of surgery (p = 0.30). Conclusion:The only modifiable risk factor identified was fixation method. When considering blood transfusion requirements in isolation, we suggest a potential benefit in using a DHS for intertrochanteric and femoral neck fractures amenable to DHS fixation.Contexte : La fracture de la hanche est un traumatisme fréquent, qui cause une perte sanguine et nécessite souvent la transfusion de produits sanguins. Nous avons tenté d'identifier les facteurs de risque associés à une hausse du nombre des transfusions sanguines chez des patients ayant subi une fracture de la hanche, en particulier les facteurs modifiables.Méthodes : Au cours d'une étude rétrospective, on a revu les cas de tous les patients chez qui on avait pratiqué une ostéosynthèse pour une fracture de la hanche survenue entre octobre 2005 et février 2010. La nécessité d'une transfusion sanguine a été associée à d'éventuels facteurs de risque, dont l'âge, le sexe, le taux d'hémoglobine préopéra-toire, le type de fracture, la technique d'ostéosynthèse, et d'autres facteurs encore.Résultats : Au total, 835 patients avaient subi une ostéosynthèse pour fracture de la hanche au cours de la période à l'étude; 631 satisfaisaient les critères d'inclusion à l'étude et parmi eux, 249 (39,5 %) ont reçu une transfusion sanguine. On a observé l'existence d'un lien entre la nécessité d'une transfusion sanguine et le sexe féminin (p = 0,018), une plus faible concentration d'hémoglobine préopératoire (p < 0,001), le type de fracture (p < 0,001) et la technique d'ostéosynthèse (p < 0,001). Par rapport aux fractures du col fémoral, le risque de transfusion sanguine était 2,37 fois plus é...

BackgroundFollowing hip or knee arthroplasty, it is clinically warranted to get patients functional as quickly as possible. However, valid tools to assess function shortly after knee or hip arthroplasty are lacking. The objective was to compare the clinimetric properties of four instruments to assess function shortly after arthroplasty.MethodsOne hundred eight patients undergoing hip or knee arthroplasty were assessed preoperatively, 1 and 2 days postoperatively, and 2 and 6 weeks postoperatively with the Timed Up and Go (TUG), Iowa Level of Assistance Scale (ILAS), Postoperative Quality of Recovery Scale (PQRS), and Readiness for Hospital Discharge Scale (RHDS). Descriptive data, floor and ceiling effects, responsiveness, interpretation and construct validity were determined.ResultsOnly the ILAS and RHDS support subscale demonstrated floor or ceiling effects. A large deterioration from preoperative to postoperative, followed by large improvements after surgery were seen in the TUG and ILAS scores. The RHDS personal status subscale and the PQRS pain and function dimensions demonstrated large improvements after surgery. Changes in the RHDS global scale and personal status subscale, PQRS pain dimension and TUG were significantly related to patient perceived improvement. Minimal important changes were obtained for the RHDS global (1.1/10) and personal status subscale (2.3/10), and the TUG (43.4 s at 6 weeks). For construct validity, the PQRS function dimension and RHDS were moderately related to the TUG or ILAS. The correlation between TUG and ILAS was high from preoperative to postoperative day 2, but substantially decreased at 2 and 6 weeks.ConclusionsThe TUG and RHDS personal status subscale demonstrated the best clinimetric properties to assess function in the first 6 weeks after hip or knee arthroplasty.

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ObjectivesPatient function after arthroplasty should ideally quickly improve. It is not known which peri-operative function assessments predict length of stay (LOS) and short-term functional recovery. The objective of this study was to identify peri-operative functions assessments predictive of hospital LOS and short-term function after hospital discharge in hip or knee arthroplasty patients.MethodsIn total, 108 patients were assessed peri-operatively with the timed-up-and-go (TUG), Iowa level of assistance scale, post-operative quality of recovery scale, readiness for hospital discharge scale, and the Western Ontario and McMaster Osteoarthritis Index (WOMAC). The older Americans resources and services activities of daily living (ADL) questionnaire (OARS) was used to assess function two weeks after discharge. ResultsFollowing multiple regressions, the pre- and post-operative day two TUG was significantly associated with LOS and OARS score, while the pre-operative WOMAC function subscale was associated with the OARS score. Pre-operatively, a cut-off TUG time of 11.7 seconds for LOS and 10.3 seconds for short-term recovery yielded the highest sensitivity and specificity, while a cut-off WOMAC function score of 48.5/100 yielded the highest sensitivity and specificity. Post-operatively, a cut-off day two TUG time of 31.5 seconds for LOS and 30.9 seconds for short-term function yielded the highest sensitivity and specificity. ConclusionsThe pre- and post-operative day two TUG can indicate hospital LOS and short-term functional capacities, while the pre-operative WOMAC function subscale can indicate short-term functional capacities.Cite this article: Bone Joint Res 2015;4:145–151.

The b subunit dimer in the peripheral stator stalk of Escherichia coli ATP synthase is essential for enzyme assembly and the rotational catalytic mechanism. Recent protein chemical evidence revealed the dimerization domain of b to contain a novel two-stranded right-handed coiled coil with offset helices. Here, the existence of this structure in more complete constructs of b containing the C-terminal domain, and therefore capable of binding to the peripheral F 1 -ATPase, was supported by the more efficient formation of intersubunit disulfide bonds between cysteine residues that are proximal only in the offset arrangement and by the greater thermal stabilities of crosslinked heterodimers trapped in the offset configuration as opposed to homodimers with the helices trapped in-register. The process of oxidative phosphorylation in mitochondria and bacteria, or photophosphorylation in chloroplasts, requires the enzyme F 1 F 0 -ATP synthase to utilize the energy of the transmembrane proton gradient for the production of ATP from ADP and P i . The enzyme functions as a molecular motor, with rotor and stator complexes consisting of subunits from both the membrane-peripheral F 1 and membrane-integral F 0 sectors of the protein. In the Escherichia coli enzyme, F 0 contains three subunits in an ab 2 c 10 stoichiometry, whereas F 1 has five subunits in the stoichiometry of ␣ 3 ␤ 3 ␥␦⑀. The ␥⑀c 10 subunits compose the rotor, and b 2 ␦ forms the stator. As the rotor is driven by the passage of protons through a pore formed by the c and a subunits of F 0 , rotation of ␥ within the ␣ 3 ␤ 3 hexamer of F 1 causes conformational changes in the catalytic nucleotidebinding sites located on the ␤ subunits, promoting ATP synthesis and release. One function of the b 2 ␦ stator is to hold the ␣ 3 ␤ 3 hexamer against the rotational torque, as otherwise ␣ 3 ␤ 3 would simply turn with the rotor rather than undergoing the conformational changes associated with the formation and release of ATP. In anaerobic or facultative bacteria, the enzyme can function as a proton pump, hydrolyzing ATP to drive protons out of the cytoplasm, against the electrochemical gradient. For recent reviews see Refs.