Management of Nonunion at 4 Months After Conservative Care
Surgical fixation is strongly recommended for fractures with nonunion after 4 months of conservative care, as this approach provides the best outcomes for morbidity, mortality, and quality of life.
Definition and Assessment of Nonunion
Nonunion is defined as a fracture that has not healed within the expected timeframe despite appropriate treatment. At 4 months post-injury, persistent fracture lines with either:
- No callus formation (atrophic nonunion)
- Callus that does not bridge the fracture site (hypertrophic nonunion)
Indications for Surgical Intervention
The following findings strongly indicate the need for surgical management:
- Persistent pain at the fracture site after 4 months of conservative care
- Radiographic evidence showing persistent fracture line
- Functional limitations affecting activities of daily living
- Evidence of mechanical instability
Surgical Management Options
1. Long Bone Fractures
- Plate Osteosynthesis: Provides rigid fixation and compression across the fracture site
2. Small Bone Fractures
- Intramedullary Fixation: Particularly effective for fifth metatarsal base nonunions
- Percutaneous screw fixation without fracture site preparation has shown excellent results with union achieved in all patients by 3 months 3
- Bridging Plate Fixation: Useful for small fracture fragments
- Effective for nonunion of stress fractures at the base of the second metatarsal 4
3. Biological Augmentation
- Autogenous Bone Grafting: Essential component of surgical management
- Provides osteogenic, osteoconductive, and osteoinductive properties
- Typically harvested from iliac crest
- Addressing Sclerotic Bone: Freshening of bone ends at nonunion site is crucial for healing
Special Considerations
Age-Related Factors
- In patients >55 years, the evidence does not demonstrate clear superiority of surgical vs. conservative treatment for some fracture types 1
- However, for established nonunion at 4 months, surgical intervention is still indicated regardless of age
Bone Stimulation
- Low-intensity pulsed ultrasound (LIPUS): Should NOT be used as it does not result in accelerated healing or lower rates of nonunion 1
- The BMJ guidelines explicitly recommend against LIPUS for bone healing 1
Metabolic Optimization
- Address potential metabolic factors contributing to nonunion:
- Vitamin D and calcium supplementation (1000-1200 mg calcium/day and 800 IU vitamin D/day)
- Smoking cessation (smoking increases nonunion rates and leads to inferior clinical outcomes) 1
Surgical Techniques Based on Nonunion Type
Hypertrophic Nonunion
- Characterized by abundant callus formation but failure of bridging
- Treatment: Rigid fixation to provide stability without extensive bone grafting
- Most common type (26/27 cases in pediatric forearm fractures) 5
Atrophic Nonunion
- Characterized by minimal biological activity and poor vascularity
- Treatment: Requires both mechanical stability and biological stimulation
- Rigid fixation
- Bone grafting
- Consider adjuvant biological therapies
Post-Surgical Management
- Early mobilization with functional treatment rather than immobilization
- Appropriate pain management with minimal opioid use
- Regular radiographic follow-up to assess healing progress
- Physical therapy to restore function and strength
Pitfalls and Caveats
- Infection Assessment: Always rule out infection before surgical intervention for nonunion
- Technical Factors: Open reduction and technical problems during initial surgery are risk factors for nonunion 5
- Conservative Management: While conservative management may be successful in some pediatric cases 5, adult nonunions at 4 months generally require surgical intervention
- Timing: Delaying surgical intervention beyond 4 months of nonunion may lead to poorer outcomes and prolonged disability
By following this evidence-based approach to nonunion management at 4 months after conservative care, optimal outcomes regarding morbidity, mortality, and quality of life can be achieved.