Aim of the study: According to the literature, atraumatic shoulder dislocations occur without or only minor trauma,self-reduction and no or little pain. Little is known about intraarticular pathology in this entity. It was the purpose of our study to evaluate such findings.
Methods: During a 2-year period,226 patients had surgery for shoulder dislocation.28 patients met the criteria for atraumatic dislocation as above (group A). Patients with bony pathology or recurrent microtrauma were excluded. All had been treated with a rehabilitation program without success.28 consecutive patients with surgery after posttraumatic dislocation served as a control group (group B). At the beginning of the surgery,arthroscopy was performed in all patients and the intraarticular findings were recorded. For the capsulo-labral pathology,we determined 3 types: type I had capsular elongation or scarring and included so called "non-Bankart-lesions"; type II had classic "Bankart"-lesions and type III more complex capsulo-labral lesions like e.g. "ALSPA"-lesions.
Results: The mean age in group A was 27.6 y and 26.2 y in group B.12 patients in group A and 5 in group B were female. The average no.of dislocations was 10 (1-30) or 9 (1-28), respectively. In group A we saw type I lesions in 11 patients (39.3%), type II lesions in 9 (32.1%) and type III lesions in 8 (28.6%) patients. In group B we found type I lesions in 8 (28.6%), type II lesions in 4 (14.3%) and type III lesions in 16 (57.1%) patients.Hill-Sachs lesions were found in 22 (78.6%) and 23 (82.1%) of the patients, respectively.Also, we saw chondral glenoid damage, cuff lesions and SLAP-lesions in both groups.
Conclusion: The above mentioned criteria for atraumatic shoulder dislocation do not exclude intraarticular pathology comparable to posttraumatic cases, at least for patients, who do not respond to a conservative treatment. Besides the etiology, the given pathology must be considered for therapy.