抄録
The purpose of this study is to examine the effects of conservative treatment of initial traumatic anterior dislocation of the shoulder.
Materials and methods: From December 1985 to April 1995,527 patients with traumatic anterior dislocation of the shoulder were initially treated at Zao hospital. Questionnaires about the history of the dislocation, glenohumeral joint stability, immobilization time and other factors were sent to them by mail in December 1995. Then the frequency of instability, the relevant prognostic factors and the effects of immobilization after the initial dislocation were statistically analyzed.
Results: Three hundred and twenty-four patients answered the questionnaire, including 176 with initial dislocation. One hundred and fourteen (65%) had no instability, while 62 (35%) had instability (44 with a redislocation and 18 with an apprehension of dislocation) at an average follow-up of 50 months after the initial dislocation. Shoulder instability was present at the follow-up in 65% of 20 patients under 20years of age. The rate decreased to 40% in 102 patients aged 20 to 29 years, and was only 4% in 24 patients over the age of 40. The rate was 55% in 29 patients with less than 1 week of immobilization, but decreased to 23% in 89 patients with more than 3 weeks of immobilization. The rate in 20 patients with a greater tuberosity fracture was significantly low (5%). We also assessed the incidence of shoulder instability in relation to both age and immobilization time in patients without a greater tuberosity fracture. More than 3 weeks of immobilization was not such an effective treatment for patients under 20years of age, but effective for patients over 20.
Conclusion: The age at the time of the initial dislocation, the presence of a greater tuberosity fracture and the immobilization time were significant determinants of shoulder instability after an initial dislocation. More than 3 weeks of immobilization was not such an effective treatment for patients under 20years of age, but effective for patients over that age.
