Anterior Elbow Dislocation with Radial Neck Fracture- A Variant of the Terrible Triad and a Review of the Literature

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Terrible triad injuries of the elbow typically present as posterior elbow dislocations with an associated radial head and coronoid fracture. We report an atypical presentation of this injury pattern with an anterior dislocation of the elbow with a radial neck and coronoid tip fracture, as well as a humeral avulsion of the lateral ulnar collateral ligament (LUCL). This patient underwent open reduction and internal fixation of her radial neck fracture and suture anchor fixation of the avulsed LUCL through a lateral approach to the elbow. She has since regained painless and functional range of motion of her elbow. This case highlights the importance of the injury mechanism, fracture pattern and intraoperative stress tests in identifying the crucial injured components of the elbow. Addressing the bony injuries alone without reconstituting the soft tissue restraints of the elbow would invariably lead to persistent instability, arthrosis and poor outcome.

The elbow joint is the second most commonly dislocated joint in adults, after the shoulder. 90% of elbow dislocations are posterior dislocations, most of which are simple posterior dislocations that follow a predictable sequence of soft tissue disruptions that eventually lead to a frank dislocation as described by O’Driscoll. By comparison, anterior dislocations are much less common, and they usually occur in conjunction with an olecranon fracture. An anterior elbow fracture-dislocation in the absence of a proximal ulna fracture is exceedingly rare with scant literature on the pathophysiology of these injuries. We present a rare case of an anterior elbow fracture-dislocation with a radial head fracture and review of the existing literature on anterior elbow fracture-dislocations in the absence of a proximal ulna fracture.

The patient is a 56-year old lady who fell on a flexed right el bow after tripping over a carpet. At the Emergency department, initial radiographs revealed an anterior dislocation of the right elbow with a radial neck fracture.Closed reduction was successfully performed under conscious sedation by extending the elbow and applying a posteriorly directed force on the proximal ulna. She was subsequently followed up in the Orthopedic Specialist Outpatient Clinic and computerized tomography scans revealed a coronoid tip fracture as well as an impacted, anteriorly angulated radial neck fracture. Stress radiograph views done in the clinic revealed an incongruously reduced elbow joint.