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Progressive valgus ankle deformity is a problematic postoperative donor-site morbidity of a vascularized fibular graft in children. To prevent this complication, tibiofibular metaphyseal synostosis (the Langenskiöld procedure) has been recommended. The authors objectively evaluated the preventive and therapeutic effects of this procedure on five children who had received free vascularized fibular grafts. Their average age at the time of operation was 3 years (range: 1 to 9 years). The Langenskiöld procedure was performed primarily in four patients, and not in one patient. The anteroposterior (A-P) mortise angle and the empirical axis of the donor-site ankle were measured radiographically. With regard to the A-P mortise angle, four of five patients showed valgus with a mild lateral wedging of the distal tibial epiphysis. The patient who did not receive the operation showed the largest A-P mortise angle and mild osteoarthritic changes. The empirical axis exceeded normal range in all of the five patients. These observations indicated that valgus deformity of the ankle in children after harvesting a vascularized fibular graft is inevitable, even if the Langenskiöld procedure is performed. The procedure can delay the ankle valgus. The authors recommend close follow-up of the children who receive the Langenskiöld procedure after harvesting a vascularized fibular graft.

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Environmental nitration of PAHs by nitrogen oxides on airborne particulates and identification and quantification of nitro-PAHs in them have been studied on fluoranthene and pyrene because of their large abundance. However, the direct mutagenic activity of these nitro-PAHs can account for only up to about 20% of the total direct mutagenic activity of airborne particulate samples, and the presence of unknown mutagenic nitro-PAHs was suggested. 1and 2-Nitrotriphenylenes were first identified and quantified in ambient particulate samples collected in Tokyo. Their mutagenicity and formation by laboratory reactions of triphenylene deposited on a filter with NO 2 / NO 3 /N 2 O 5 were also investigated. The concentrations of 1-and 2-nitrotriphenylenes were much higher than that of 1-nitropyrene in the same samples. 2-Nitrotriphenylene showed over 2 orders of magnitude greater mutagenic activity than 1-nitrotriphenylene in both strains TA98 and YG1024 (18 and 480 revertants/nmol for 1-nitrotriphenylene and 3800 and 101 700 revertants/nmol for 2-nitrotriphenylene in TA98 and YG1024). The mutagenic 2-nitrotriphenylene was expected to contribute largely to the total mutagenic activity of the extracts from airborne particulates. In addition, more effective formation of nitrotriphenylenes by the nighttime reaction of triphenylene in the presence of O 3 in the dark can explain the observation of high nitrotriphenylene concentration in the nighttime samples.