McLaughlin's 1952 case series of 22 posterior shoulder dislocations defines why this injury is missed and what to do about it. It establishes the clinical signs, radiographic approach, and operative anatomy of posterior dislocation. The central question: how do you find this diagnosis, and how do you treat it acutely, chronically, and in the recurrent setting?
When a patient presents with a stiff, painful shoulder after a seizure or electric shock, posterior dislocation is the diagnosis until proven otherwise. Anteroposterior X-rays are frequently non-diagnostic. Get a tangential scapular view (central ray along the scapular spine axis) — McLaughlin showed this view definitively confirms or excludes the diagnosis without additional patient discomfort.
On exam, fixed internal rotation and complete absence of external rotation are the hallmarks. The findings are subtle enough that you must compare both shoulders side-by-side. This paper is why we do that comparison routinely.
Acute cases treated promptly with closed reduction and a sling recover fully in 2-3 weeks. Delay is the enemy: 16 of 22 patients in this series were missed initially, and prolonged dislocation leads to irreversible articular destruction requiring humeral head excision.
For unstable or recurrent cases, the operative finding is the McLaughlin lesion: a vertical compression defect in the anterior humeral head engaging the posterior glenoid rim. Subscapularis transposition into this defect (the McLaughlin procedure) eliminates the mechanical engagement and prevents redislocation.
McLaughlin's 1952 case series of 22 posterior shoulder dislocations defines why this injury is missed and what to do about it. It establishes the clinical signs, radiographic approach, and operative anatomy of posterior dislocation. The central question: how do you find this diagnosis, and how do you treat it acutely, chronically, and in the recurrent setting?
When a patient presents with a stiff, painful shoulder after a seizure or electric shock, posterior dislocation is the diagnosis until proven otherwise. Anteroposterior X-rays are frequently non-diagnostic. Get a tangential scapular view (central ray along the scapular spine axis) — McLaughlin showed this view definitively confirms or excludes the diagnosis without additional patient discomfort.
On exam, fixed internal rotation and complete absence of external rotation are the hallmarks. The findings are subtle enough that you must compare both shoulders side-by-side. This paper is why we do that comparison routinely.
Acute cases treated promptly with closed reduction and a sling recover fully in 2-3 weeks. Delay is the enemy: 16 of 22 patients in this series were missed initially, and prolonged dislocation leads to irreversible articular destruction requiring humeral head excision.
For unstable or recurrent cases, the operative finding is the McLaughlin lesion: a vertical compression defect in the anterior humeral head engaging the posterior glenoid rim. Subscapularis transposition into this defect (the McLaughlin procedure) eliminates the mechanical engagement and prevents redislocation.