Clinical assessment of 115 cases of hindfoot fusion with two different types of graft: Allograft+DBM+bone marrow aspirate versus autograft+DBM.

INTRODUCTION: Nonunion is a common complication (15%) of hindfoot and ankle arthrodesis. Autograft can improve the fusion rate because of its osteoconductive, osteoinductive and osteogenic properties. However, autograft harvesting is a source of morbidity. One alternative is to combine allograft with demineralized bone matrix (DBM) and iliac bone marrow aspirate (BMA). This combination graft has similar biological properties to healthy bone. When used alone, allograft has osteoconductive and sometimes structural properties. DBM provides osteoinduction and improves the osteconductivity. BMA adds cells and thereby osteogenic potential. HYPOTHESIS: Given its intrinsic properties, allograft-DBM-BMA is as effective as autograft-DBM treatment while simplifying the clinical practice. MATERIAL AND METHODS: One hundred and fifteen cases of ankle and hindfoot arthrodesis were studied in 82 patients divided in two groups: autograft-DBM vs allograft-DBM-BMA. Treatment effectiveness was assessed using clinical (time to fusion, fusion rate) and radiological (trabecular bone bridge, disappearance of joint space) criteria. A CT scan was done in 60% of cases when fusion could not be confirmed using the clinical and radiological criteria. RESULTS: There was no significant difference between the two groups in terms of fusion rate, time to fusion, number of heterotopic ossifications, revision rate and quantity of DBM used. The nonunion rate was 18% in the autograft group and 13% in the allograft group. The infection rate was 11% in the autograft and 4% in the allograft group. DISCUSSION: Allograft-DBM-BMA is an alternative to autograft-DBM that provides similar effectiveness without increasing the number of nonunion or complications. Osteonecrosis and surgical revision are risk factors. LEVEL OF EVIDENCE: III retrospective study.

Validity of diagnosis using the French translation of the semi-structured interview for seizure classification.

PURPOSE: The purpose of this study was to assess the acceptability and validity of the French cross-cultural translation of a semistructured interview for seizure classification (SISC). We used the first revised version, the original of which was validated in 1990. METHODS: We administered the French SISC to a sample of 67 adults older than 15 years, comprising 17 controls and 50 patients with epilepsy (without provoked or isolated seizures). A cross-cultural translation was made from American English into French. Medical records were reviewed by epileptologists, who classified seizures, syndromes, and risk factors in accordance with the International League Against Epilepsy (ILAE) classifications. Agreement between interview- and physician-based diagnoses was assessed with a kappa coefficient (kappa) at each level of the recognized schemes for the classification of seizures (both broad and specific categories), syndromes, and risk factors. RESULTS: The sensitivity of the French SISC in diagnosing an epileptic seizure was 100%, with a specificity of 94%. Interview-based diagnoses agreed with those of physicians in 90% of patients for broad seizure categories [i.e., generalized or focal in origin (kappa = 0.74)]. When diagnoses agreed on focal origin, the agreement on seizure types-simple or complex-was 91% (kappa = 0.84). Among generalized seizures, the agreement was 73% (kappa = 0.60). Agreement on epilepsy syndromes was excellent for generalized epilepsy but moderate for focal epilepsy. Agreement on identified risk factors was 93%. CONCLUSIONS: The kappa coefficients demonstrated a good level of reliability. These results support the acceptability of this type of interview and the validity of the French version of the SISC.

Electro-optical studies on synthetic polyelectrolytes. IV. Electric polarizability and conformation of poly-N-methyl-2-vinylpyridinium bromide in aqueous solution.

Measurements of the relaxation time on aqueous solutions of the title polyelectrolyte as a function of the concentration and of the molecular weight show that its conformation at very high dilution can be better accounted for by a weakly bending rod or wormlike chain model, with persistence length ranging from 200 to 400 A. The analysis of the field strength dependence of the electric birefringence yields electric polarizability values which increase sharply with the dilution and are not significantly dependent upon the molecular weight. This has been tentatively interpreted on the basis of the theories derived by Oosawa and by Mandel and Van der Touw. The partially flexible model proposed by the latter authors allow to identify the electric polarizability calculated from electro-optical data to the specific dielectric increment measured in the high frequency range; both parameters appear to be molecular weight independent. The electric polarizability obtained from the Kerr effect would be originated in the induced dipoles caused by the delocalization of the bound counterions along rigid subunits whose length seems however to differ from the persistence length.

Electro-optical studies on synthetic polyelectrolytes. I. Ultraviolet electric dichroism of poly-N-alkylvinylpyridinium bromides in aqueous solution.

The electric dichroism of aqueous solutions of poly-2- and 4-vinylpyridinium bromides has been measured in the 220 to 300 nm region. From the knowledge of the assignments of the absorption bands, the orientation of the pyridinium ring with respect to the macromolecular axis was determined for the poly-N-butyl-4-vinylpyridium bromide. An estimation of the birefringence contribution in the visible region originating from these ultraviolet dichroic bands revealed that the negative birefringence observed mainly arose from electronic transitions at shorter wavelengths.