Isolated infraspinatus musculotendinous junction tear treated with open repair and dermal allograft augmentation: a case report with 5-year outcome

We report the 5-year outcome of an isolated, atraumatic full-thickness infraspinatus myotendinous junction tear treated with open surgical repair. The index patient developed severe pain and weakness in external rotation strength following a subacromial corticosteroid injection. Magnetic resonance imaging and ultrasound of the shoulder demonstrated a full-thickness myotendinous junction tear with extensive muscle edema, mild atrophy and a spinoglenoid notch varix. Due to persistent, worsening pain and presence of ER weakness, the patient underwent primary infraspinatus muscle–tendon repair with allograft augmentation via an arthroscopic-assisted open posterior approach. The patient had an uneventful postoperative course with a resolution of pain and improvement in ER strength, which is maintained at the latest 5-year follow-up. This case report highlights a favorable long-term outcome of an isolated infraspinatus myotendinous junction tear treated with primary muscle–tendon repair and dermal allograft augmentation.