Treatment of Non-Union Fractures
The optimal treatment for non-union fractures involves complete excision of the pseudarthrosis site, sufficient autogenous bone grafting, and proper fixation method, with the combined Ilizarov fixator with intramedullary fixation showing high union rates of 93.3%. 1
Definition and Prevalence
A non-union fracture is defined as a fracture that fails to heal within the expected time frame, occurring in approximately 3-5% of all fractures 2. Non-unions have a significant negative impact on mental and physical functioning and quality of life.
Risk Factors for Non-Union
Several factors contribute to the development of non-union:
- Open method of fracture reduction
- Open fracture
- Post-surgical fracture gap
- Smoking
- Infection
- Wedge or comminuted fracture types
- High degree of initial fracture displacement
- Inadequate mechanical stability from implants
- Fracture location in poorly vascularized bone regions
- Tibial fractures (higher risk) 3
Diagnostic Approach
Diagnosis of non-union involves:
- Clinical assessment: Persistent pain, abnormal mobility at fracture site
- Radiographic evaluation: Absence of bone bridging, sclerotic bone ends
- Laboratory tests: Inflammatory markers (ESR, CRP) to rule out infection
- Histopathology: Presence of neutrophils (>5 PMNs/high power field) confirms infection-related non-union 1
Treatment Algorithm
1. Assessment Phase
- Determine if the non-union is infected or aseptic
- Evaluate fracture stability and bone quality
- Assess soft tissue condition
2. For Infected Non-Union (Fracture-Related Infection)
- Surgical debridement of all infected and necrotic tissue
- Deep tissue sampling for microbiology and histopathology
- Appropriate antimicrobial therapy based on culture results
- Consider one of two approaches 1:
- Debridement, antimicrobial therapy, and implant retention (DAIR) for early infections (<3-6 weeks)
- Debridement with implant removal/exchange for established infections
3. For Aseptic Non-Union
Surgical approach based on fracture location and characteristics:
For long bone non-unions (particularly lower extremity):
For upper limb non-unions (particularly clavicle):
For all non-unions:
- Complete excision of the pseudarthrosis site
- Sufficient autogenous bone grafting (iliac crest preferred)
- Proper method of fixation based on fracture location and characteristics
4. Bone Grafting Options
- Autogenous bone graft (gold standard) - provides osteogenic, osteoinductive, and osteoconductive properties 4
- Vascularized fibular graft (VFG) - reserved for cases where other techniques have failed (88.2% final union rate but 45% refracture rate) 1, 4
- Consider biological augmentation with:
- Bone marrow aspirate
- Platelet-rich plasma
- Demineralized bone matrix
Special Considerations
- Low-intensity pulsed ultrasound (LIPUS) is not recommended for bone healing as evidence suggests no benefit 1
- Younger patients (<45 years) with focal lesions may benefit from mosaicplasty for osteochondral defects 4
- For tibial defects, acute docking is recommended for defects <5cm with good soft tissue coverage 4
- Defects >5cm increase risk of neurovascular compromise and may require alternative approaches 4
Outcomes and Complications
- Union rates with combined Ilizarov and intramedullary fixation: 84-100% 4
- Average union time with Ilizarov method: 8.3 months 4
- Non-union rates: 5-12.3% with Ilizarov method, 6% with combined Ilizarov/intramedullary fixation 4
- Refracture rates: highest with VFG (45%), lowest with cross-union technique (22.5%) 1, 4
By following this structured approach to the management of non-union fractures, clinicians can optimize outcomes and minimize complications for patients with this challenging condition.