Treatment of Unstable Elbow Dislocation with Mason Type 2 Radial Head Fracture
This injury requires surgical intervention with open reduction and internal fixation (ORIF) of the radial head, repair of lateral collateral ligament complex, and early motion protocols to restore stability and optimize functional outcomes. 1, 2
Surgical Management Algorithm
Primary Surgical Intervention
Radial head fixation is mandatory for Mason type 2 fractures in the setting of elbow instability, as preservation of radiocapitellar contact is critical for restoring elbow stability 2. ORIF of the radial head yields significantly superior outcomes compared to nonoperative treatment, with 90% good/excellent results versus 44% for closed treatment 3.
Lateral collateral ligament complex repair must be performed in all cases of unstable elbow dislocation, as failure to repair this structure is associated with recurrent instability and poor outcomes 1, 2. The lateral ulnar collateral ligament is the primary restraint to posterolateral rotatory instability 4.
Assessment of Additional Injuries
Evaluate for coronoid fracture using CT imaging if not clearly visible on plain radiographs, as coronoid involvement creates the "terrible triad" pattern with high instability risk 2. If a coronoid fracture is present, attempt internal fixation when technically feasible 1.
Test medial collateral ligament integrity intraoperatively after radial head fixation and lateral ligament repair 1. If the elbow remains unstable to valgus stress after these repairs, proceed with medial collateral ligament repair 1.
Adjuvant Stabilization
Apply hinged external fixation if concentric joint stability cannot be achieved after completing all bony and ligamentous repairs 1, 5. This serves as a salvage option for persistent instability and allows protected early motion 1.
Alternatively, temporary bridge plate stabilization across the elbow joint can protect the repair while maintaining reduction, followed by staged removal 6.
Postoperative Protocol
Initiate early range of motion at 7-10 days postoperatively once surgical stability is confirmed 1. This early mobilization is critical for preventing stiffness, which is a major source of disability in these injuries 1.
Avoid prolonged immobilization, as extended casting or splinting leads to poor functional outcomes and increased stiffness 1, 2.
Expected Outcomes
With this surgical protocol, patients achieve an average flexion-extension arc of 112° and Mayo Elbow Performance Score of 88 points at 34 months 1. Concentric stability is restored in 94% of cases when following this comprehensive approach 1.
Critical Pitfalls to Avoid
Never resect the radial head in this injury pattern, as all patients with satisfactory outcomes in the literature retained their radial head, while radial head resection was associated with recurrent instability and poor results 2. If the radial head is not reconstructible, prosthetic replacement is preferred over resection 5, 2.
Do not miss the coronoid fracture, as its presence dramatically increases instability risk and changes the treatment algorithm 2. CT imaging should be obtained if there is any uncertainty 2.
Failure to repair the lateral collateral ligament is associated with redislocation rates approaching 100% in some series 2. This repair is non-negotiable in unstable elbow dislocations 1.
Nonoperative treatment of displaced Mason type 2 fractures in unstable elbows results in significantly higher rates of pain, functional limitations, loss of strength, and radiographic arthritis 3.