Risk factors associated with non-union after triple pelvic osteotomy (Toennis and Kalchschmidt technique): a case-control study and review of the literature.

INTRODUCTION: Dysplasia of the hip is a well known cause of secondary osteoarthritis of the hip. The triple pelvic osteotomy (TPO), according to the technique described by Toennis and Kalchschmidt, is a well established procedure to address dysplasia of the hip joint. Non-unions after triple pelvic osteotomies are rare and can occur at each of these osteotomies. The literature is lacking in studies investigating larger group of patients with non-unions after triple pelvic osteotomy. The aim of this study is to evaluate risk factors leading to a non-union after triple pelvic osteotomy. METHODS: A total of 53 patients with a non-union after triple pelvic osteotomy were included in this retrospective case-control. In addition, we identified a cohort of randomly selected patients undergoing hardware removal after triple pelvic osteotomy ("union" group) but had not developed non-union as the control group. This control group underwent the same procedure by the same group of surgeons in the same time period. The variables obtained from the review of the two groups were analyzed using appropriate statistical methods including Bivariable Analysis (p < 0.005) and Multivariable logistic regression analysis (p < 0.015). RESULTS: We identified a total of 53 patients out of the 3269 who had undergone TPO and had developed a non-union. The control group consisted of 117 patients who did not experience a non-union. Bivariable analysis of basic demographic characteristics demonstrated that gender, BMI, smoking, preoperative CE angle and degree of surgical correction did not differ significantly between the groups. There was a statistically significant (p < 0.05) difference between age (31.5 ± 9.4 vs. 27.5 ± 9.0 in the non-union and union groups, respectively; p = < 0.001) and postoperative CE angle (34.4 ± 5.0 vs. 32.8 ± 3.5 in the non-union and union groups, respectively; p = 0.02). Multivariable analysis demonstrated that an age over 30 was significantly associated with non-union (p = 0.01, OR 2.6, 95% CI 1.3-5.3). CONCLUSION: Non-unions after TPO are rare. A higher age and higher degree of surgical correction might be associated risk factors for developing a non-union. Furthermore, smoking, obesity and previous hip surgeries might also contribute to developing a non-union after triple pelvic osteotomy.

Upstream signaling of protein kinase C-epsilon in xenon-induced pharmacological preconditioning. Implication of mitochondrial adenosine triphosphate dependent potassium channels and phosphatidylinositol-dependent kinase-1.

Xenon elicits preconditioning of the myocardium via protein kinase C-epsilon. We determined the implication of (1) the mitochondrial adenosinetriphosphate dependent potassium (K(ATP)) channels and (2) the 3'phosphatidylinositol-dependent kinase-1 (PDK-1) in activating protein kinase C-epsilon. For infarct size measurements, anaesthetized rats were subjected to 25 min of coronary artery occlusion followed by 120 min of reperfusion. Rats received xenon 70% during three 5-min periods before ischaemia with or without the K(ATP) channel blocker 5-hydroxydecanoate or Wortmannin as PI3K/PDK-1 inhibitor. For Western blot, hearts were excised at five time points after xenon preconditioning (Control, 15, 25, 35, 45 min). Infarct size was reduced from 42+/-6% (mean+/-S.D.) to 27+/-8% after xenon preconditioning (P<0.05). Western blot revealed an increased activation of PKC-epsilon after 45 min and of PDK-1 after 25 min during xenon preconditioning. 5-hydroxydecanoate and Wortmannin blocked both effects. PKC-epsilon is activated downstream of mitochondrial K(ATP) channels and PDK-1. Both pathways are functionally involved in xenon preconditioning.