Posterior superior internal impingement: an evidence-based review [corrected]

Area of Science:

• Orthopedics
• Sports Medicine
• Shoulder Surgery

Background:

• Internal impingement syndrome is a distinct shoulder condition characterized by soft tissue compression in the posterosuperior glenoid.
• It requires differentiation from external impingement, which involves the subacromial space.
• The increasing recognition of internal impingement highlights its clinical significance.

Purpose of the Study:

• To differentiate internal impingement from external impingement.
• To explore the potential etiologies of internal impingement syndrome.
• To outline current treatment strategies, including conservative and surgical options.

Main Methods:

• Literature review and conceptual analysis of internal impingement syndrome.
• Comparison of internal and external impingement pathologies.
• Discussion of non-operative and operative treatment approaches.

Main Results:

• Internal impingement involves the rotator cuff, capsule, and glenoid, differing from external impingement.
• Hypothesized causes include anterior instability, posterior capsule contracture, and scapular dyskinesis.
• Conservative treatment (pain management, stretching, strengthening) is the first line; surgery is for refractory cases.

Conclusions:

• Internal impingement syndrome is an evolving concept with increasing recognition.
• Conservative management is primary, but surgical outcomes improve with concurrent instability treatment.
• Further research into etiology and optimized surgical techniques is warranted.