[A study on the prevalence and risk factors of muscular fibrotic contracture in Jia-Dong Township, Pingtung County, Taiwan].

In order to examine the prevalence and risk factors of muscular fibrotic contracture (MFC) among school children in Jia-Dong Township, Pingtung County, a prevalence survey combined case-control study was carried out from January to April, 1988. All the school children aged from 6 to 19 years old were first screened at schools and then referred to the Provincial Pingtung Hospital for confirmatory diagnosis based on the non-invasion criteria. A total of 83 MFC cases were identified including 79 gluteal fibrotic contracture (GFC) patients, 3 deltoid fibrotic contracture (DFC) patients, and 1 affected both GFC and DFC. The prevalence was significantly higher in males (17.3 per 1,000) than in females (10.5 per 1,000). The prevalence was found to increase with age after 6 years of age, peaked at the age group of 13-15 years, and decline thereafter. Most MFC cases clustered in both Wen-Fon and Yuan-Wen villages locate in the southern coast of Taiwan Island. Among 83 MFC patients, 65 were further interviewed to obtain information on the risk factors of MFC. A total of 65 healthy classmates one-to-one matched with MFC cases on aged, sex, and living villages were selected as the control group which was also interviewed. The case-control study showed a positive association between the frequency of injection and the MFC in a dose-response relationship. The injection site also correlated with the development of the GFC and DFC. It was reasoned that the injection might be the most important risk factor of MFC. Follow-up study of 65 operated MFC cases indicated a high percentage (89.2%) of hyperscar formation in the incision region.