WBR1492
| Author | PageAuthor::William J Gibson |
|---|---|
| Exam Type | ExamType::Surgery Shelf |
| Main Category | |
| Sub Category | |
| Prompt | [[Prompt::A 24 year old man presents to the emergency room after his car rear-ended another at approximately 15 mph. He was driving back after pitching at his baseball game when the crash occurred, but he cannot remember the crash itself. Physical exam reveals an internally rotated shoulder, with positive Jerk test, consistent with posterior shoulder dislocation. What is the most likely cause of this patient's shoulder injury?]] |
| Answer A | AnswerA::Injury from throwing the baseball |
| Answer A Explanation | [[AnswerAExp::Throwing injuries place large amounts of stress on the posterior aspects of the should. Throwing most often injures the muscles of the rotator cuff and would result in an anterior shoulder dislocation rather than a posterior shoulder dislocation.]] |
| Answer B | AnswerB::Whiplash |
| Answer B Explanation | AnswerBExp::While whiplash is a common injury in motor vehicle accidents, whiplash would not be responsible for a posterior surgical dislocation. Whiplash would typically result in injuries to the cervical spine rather than the shoulder. |
| Answer C | AnswerC::Airbag injury |
| Answer C Explanation | [[AnswerCExp::Airbags often cause abrasions or contusions of the arms, face and chest. The collision in this vignette was a fairly low velocity collision, making the likelihood that the airbag would cause substantial harm smaller. It would be highly unlikely that an airbag would cause a posterior shoulder dislocation, especially given the speed of the collision.]] |
| Answer D | AnswerD::Seatbelt injury |
| Answer D Explanation | AnswerDExp:: |
| Answer E | AnswerE::Seizure |
| Answer E Explanation | AnswerEExp::Seizure |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::This patient most likely suffered a posterior shoulder dislocation as a result of his seizure. Posterior shoulder dislocations are rare (<5%). In most shoulder dislocations, the humerus is displaced anteriorly (>95%). Educational Objective: Posterior shoulder dislocation may be caused by seizures or electrocution. During these events, tetanic contraction of the external rotators of the shoulder can pull the humerus posteriorly out of the glenoid fossa. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Ortho, WBRKeyword::Orthopedics, WBRKeyword::Shoulder, WBRKeyword::Shoulder dislocation, WBRKeyword::Posterior shoulder dislocation, WBRKeyword::Seizure |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |