Lesion prevalence and patient outcome comparison between primary and recurrent anterior shoulder instability.

BACKGROUND: The purpose of this study was to compare lesion prevalence and treatment outcomes in patients with primary and recurrent anterior shoulder instability. METHODS: Patients who were admitted to the institution with a diagnosis of anterior shoulder instability and who underwent arthroscopic surgery between July 2006 and February 2020 were retrospectively evaluated. Minimum follow-up duration of the patients was 24 months. The recorded data and magnetic resonance imaging (MRI) of the patients were examined. Patients aged ≥40 years, with a history of shoulder region fracture, inflammatory arthritis, a history of epilepsy, multidirectional instability, nontraumatic dislocation, and off-track lesions were excluded from the study. Shoulder lesions were documented and patient outcome evaluation was made with the Oxford Shoulder Score (OSS) and visual analog scale (VAS). RESULTS: A total of 340 patients were included in the study. The mean age of patients was 25.6 years (±6.49). The recurrent instability group had a significantly higher rate of anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesions compared to the primary instability group (40.6% vs. 24.6% respectively) (P = .033). Twenty-five patients (43.9%) had superior labrum anterior and posterior (SLAP) lesions in the primary instability group and 81 patients (28.6%) had SLAP lesions in the recurrent instability group (P = .035). OSS increased for both primary (from 35 [16-44] to 46 [36-48]) (P = .001) and recurrent instability groups (from 33 [6-45] to 47 [19-48]) (P = .001). There was no significant difference between the groups regarding postoperative VAS and OSS scores (P > .05). CONCLUSIONS: Successful results were obtained in patients younger than 40 years with both primary and recurrent anterior shoulder instability after arthroscopic treatment. ALPSA lesion prevalence was higher whereas SLAP lesion prevalence was lower in patients with recurrent instability. Although the postoperative OSS was comparable between the patient groups, the failure rate was higher in the recurrent instability patients.