The purpose of this study was to know the time-course from primary shoulder dislocation to recurrence in young rugby players. We sent questionnaire about shoulder dislocation to all highschool/college rugby teams in the Kyushu area (No. of players; 5476). Based on the answers from the players who had undergone shoulder dislocations, we divided them into two groups; Group I: immobilization for 0-3 weeks at the time of initial dislocation(n=61), and Group II: immobilization for 4-7weeks (n=18). We compared the time-course from primary dislocation to recurrence between the two groups using the Kaplan-Meier method. The age of primary dislocation was between 14 and 23 years old ( ave.; 16.7 ). The probability of recurrence was 78%,44%, and 70% after one year; 85%,69%, and 81% after two years in Groups I, II, and the whole groups respectively. The average period from restart of rugby to recrurrence was 9.8,30.6, and 19.7 months in Groups I, II, and the whole groups respectively. The symptom-free period could be elongated if immobilization was done for 4 weeks or more in comparison with cases immobilized for 3 weeks or less (p<0.05). However, the high recurrence ratio showed limitations of immobilization therapy for primary shoulder dislocations of rugby players.
