In schoulders instabilty, the soft tissue has not been the subject of histological studies, as has the "bare area" or zone devoid of cartilage, the exact role of which in glenohumeral biomechanics is unknown. This research is based on the hypothesis that the antipodal lesions are constant, underestimated and that an architectural disorganization at the capsulo-ligament level could contribute to the instability of the shoulder. The aim of this study is therefore to better characterize these lesions which could be the subject of a complementary stabilization procedure even in the absence of a humeral notch

Surgery for unstable shoulders sometimes involves repairing lesions that promote instability. These lesions are identified on imaging before surgery and then during the operation, but they are macroscopically inconsistent on genuine unstable shoulders. While the importance of posterior capsuloligamentous structures (soft tissue) in antero-inferior stability has been the subject of biomechanical studies, the soft tissue has not been the subject of histological studies, as has the "bare area" or zone devoid of cartilage, the exact role of which in glenohumeral biomechanics is unknown. However, this research is based on the hypothesis that the antipodal lesions are constant, underestimated and that an architectural disorganization at the capsulo-ligament level could contribute to the instability of the shoulder. The aim of this study is therefore to better characterize these lesions which could be the subject of a complementary stabilization procedure even in the absence of a humeral notch.

Inclusion Criteria:

Instability Group

• Patient, male or female, over 18 years old and up to 40 years old
• Patient operated for antero-inferior shoulder instability
• Subject affiliated or beneficiary of a social security scheme
• Patient having signed the free and informed consent comparativ group
• Patient, male or female, over 18 years old and up to 40 years old
• Patient operated for a reason other than unstable shoulder
• Subject affiliated or beneficiary of a social security scheme
• Patient having signed the free and informed cons

Exclusion Criteria:

• History of surgery on the affected shoulder
• Capsuloligamentous disease (Ehler Danlos)
• History of instability (dislocation, subluxation) in witnesses
• Patient participating in another clinical study
• Protected patient: adult under guardianship, curatorship or other legal protection, deprived of liberty by judicial or administrative decision;
• Pregnant, breastfeeding or parturient woman;
• Patient hospitalized without consent.