Background: There is a general belief that inguinal hernias are often caused by a single strenuous event, however there are no data to support this association. This study aims to assess the frequency with which inguinal hernia is attributed to a single muscular strain and to identify predisposing factors.
Methods: All patients who underwent inguinal hernia repair under the care of one surgeon over a nine-year period were studied. Five hundred and twenty patients were sent a structured postal questionnaire.
Results: There was a 62% response rate (320). The median age of the study group was 61.5 (range 19-88) years. Out of a total 320 hernias, 51% (163) of the hernias were gradual in onset and in 42.5% (137) of hernias there was a history suggesting an association between a particular strenuous event and the sudden onset of hernia. In the sudden-onset group 101 (74%) patients had indirect hernias while in the gradual-onset group, 93 patients (57%) had indirect hernias (P < 0.05). Thirty-four patients (25%) had direct hernias in the sudden-onset group and 63 (39%) in the gradual-onset group (P < 0.05). The various predisposing factors were lifting (67.8%, 93), coughing (14.5%, 20), exercise (10.2%, 14), and gardening (7.3%, 10). Heavy work was associated with sudden inguinal herniation.
Conclusions: This study supports the hypothesis that the appearance of inguinal herniation may be attributed to a single strenuous event. Indirect hernias are more likely to present following such an event.