Locked posterior dislocation of the shoulder

Area of Science:

• Orthopedic Surgery
• Traumatology
• Radiology

Background:

• Locked posterior shoulder dislocation is an uncommon injury, frequently misdiagnosed by initial physicians.
• Common causes include motor-vehicle accidents, seizures, alcohol-related injuries, and electroshock therapy.
• The average delay in diagnosis is approximately one year, though 25 dislocations were diagnosed within six months.

Purpose of the Study:

• To evaluate the diagnostic accuracy and treatment outcomes for locked posterior shoulder dislocations.
• To highlight the importance of axillary radiography in diagnosing this condition.
• To review various surgical interventions and their success rates.

Main Methods:

• Retrospective analysis of forty patients with forty-one locked posterior shoulder dislocations.
• Diagnosis confirmed using axillary radiographs, which also assessed the impression defect size.
• Review of treatment modalities including closed reduction, tendon transfers, hemiarthroplasty, and total arthroplasty.

Main Results:

• The majority of cases were initially misdiagnosed.
• Axillary radiographs were diagnostic in all instances and showed the impression defect.
• Treatment success varied: closed reduction (6/12), subscapularis transfer (4/9), lesser tuberosity transfer (4/4), hemiarthroplasty (6/9), and total arthroplasty (9/10, with one postoperative dislocation).

Conclusions:

• Locked posterior shoulder dislocations are frequently overlooked, necessitating a high index of suspicion.
• Axillary radiography is essential for accurate diagnosis and assessment of bony defects.
• Prompt diagnosis and appropriate management, utilizing various surgical techniques, lead to successful outcomes in most patients.