Posterior shoulder dislocation. Muscle and capsular lesions in cadaver experiments

Area of Science:

• Orthopedic Surgery
• Anatomy
• Biomechanics

Background:

• Posterior shoulder dislocations are less common than anterior dislocations.
• Understanding the associated soft tissue injuries is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate the soft tissue injuries associated with provoked posterior subspinous dislocation of the humeral head in cadaveric shoulders.

Main Methods:

• Posterior subspinous dislocation was induced in 10 cadaver shoulders.
• The extent of soft tissue damage to the posterior capsule and rotator cuff muscles was evaluated.

Main Results:

• All specimens exhibited complete rupture of the posterior capsule and teres minor muscle.
• Partial tears of the infraspinatus muscle were observed in most cases.
• Lesions in the subscapularis muscle and anterior capsule were noted in the majority of specimens.

Conclusions:

• Posterior subspinous dislocation frequently involves extensive damage to the posterior shoulder structures.
• These findings highlight the significant capsulolabral and muscular disruption associated with this type of shoulder instability.