Treatment of Coronoid Process Fractures
The treatment of coronoid process fractures should be based on fracture type, size, displacement, and elbow stability, with conservative management recommended for most isolated coronoid fractures with less than 50% involvement and stable elbows, while surgical fixation is necessary for larger fragments or unstable elbows. 1, 2
Classification and Assessment
The Regan and Morrey classification system guides treatment decisions:
- Type I: Fracture of the tip (less than 25% of coronoid height)
- Type II: Fracture involving 25-50% of coronoid height
- Type III: Fracture involving more than 50% of coronoid height
- Type IV: Comminuted fracture with elbow instability
Initial imaging should include radiographs of the elbow, which are beneficial as the first-line assessment for acute elbow pain 3. If radiographs are normal or indeterminate but clinical suspicion remains high, CT without contrast is recommended to clarify fracture morphology 3.
Treatment Algorithm
Type I Fractures (Less than 25% involvement)
- Conservative treatment with brief immobilization (10-15 days) 4
- Early finger motion to prevent stiffness 5
- Consider surgical fixation only if the fragment affects elbow movement 6
Type II Fractures (25-50% involvement)
- Conservative treatment if the elbow is stable and the fragment is minimally displaced 1
- Surgical fixation (open reduction and internal fixation with anteroposterior lag screws) if the elbow is unstable 4
- Early post-operative mobilization yields better results than prolonged immobilization 4
Type III Fractures (More than 50% involvement)
- Surgical fixation is strongly recommended due to significant increase in posterior displacement under axial loading 2
- Open reduction and internal fixation with anteroposterior lag screws is the treatment of choice 4
- Address associated ligamentous injuries to restore elbow stability
Type IV Fractures (Comminuted with instability)
- Surgical reconstruction is necessary to recover elbow stability 6
- May require bone grafting or buttress plating for comminuted fragments
Complex Injury Patterns
For coronoid fractures with associated injuries (e.g., "terrible triad" with radial head fracture and elbow dislocation):
- Direct anterior approach for coronoid fixation combined with lateral approach for radial head and lateral collateral ligament repairs 7
- Stabilize with anterior-to-posterior screw fixation and buttress plating for anatomic reduction 7
- Repair or reconstruct damaged ligaments to restore stability 6
Post-Treatment Management
- Encourage early finger motion regardless of immobilization type to minimize stiffness 5
- Limit duration of immobilization to reduce complications 5
- Consider vitamin C supplementation to prevent disproportionate pain 5
- NSAIDs for pain and inflammation control 5
- Directed home exercise program including active finger motion exercises 5
Prognosis and Complications
- Most isolated coronoid fractures with stable elbows have excellent outcomes with conservative treatment 1
- Potential complications include:
- Joint stiffness (most common)
- Traumatic osteoarthritis
- Heterotopic ossification
- Elbow instability
- Chronic pain
Special Considerations
- Proper post-operative rehabilitation can decrease the occurrence of traumatic osteoarthritis 6
- Type IV fractures have significantly worse range of motion outcomes compared to other types 6
- Fractures with perfectly reduced ulnohumeral joint, competent sublime tubercle, and fractured coronoid height up to 50% can be treated without surgery with excellent results in >90% of cases 1
The biomechanical evidence clearly demonstrates that coronoid fractures involving more than 50% of the process significantly compromise elbow stability, especially in flexion beyond 60 degrees, making surgical fixation necessary in these cases 2.